- Email: [email protected]
Fe3O4 nanoparticles impregnated eggshell as a novel catalyst for enhanced biodiesel production
Accepted Manuscript Fe3O4 nanoparticles impregnated eggshell as a novel catalyst for enhanced biodiesel production
Ch. Chingakham, Asha David, V. Sajith PII: DOI: Reference:
S1004-9541(18)31820-2 https://doi.org/10.1016/j.cjche.2019.02.022 CJCHE 1424
To appear in:
Chinese Journal of Chemical Engineering
Received date: Revised date: Accepted date:
4 December 2018 19 January 2019 20 February 2019
Please cite this article as: C. Chingakham, A. David and V. Sajith, Fe3O4 nanoparticles impregnated eggshell as a novel catalyst for enhanced biodiesel production, Chinese Journal of Chemical Engineering, https://doi.org/10.1016/j.cjche.2019.02.022
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Article Fe3O4 nanoparticles impregnated eggshell as a novel catalyst for enhanced biodiesel production
2
Malabar Christian College, Calicut, India
corresponding author email: [email protected]
US
#
IP
School of Nano Science and Technology, National Institute of Technology Calicut, India
CR
1
T
Ch.Chingakham1, Asha David2 and V.Sajith1，*
AN
Abstract
M
Biodiesel is a green fuel which can replace diesel while addressing various issues such as scarcity of hydrocarbon fuels, environmental pollution etc. to an extent. The high production cost
ED
of biodiesel and the recovery of the catalyst after the transesterification process are the major challenges to be addressed in biodiesel production. In the present work, a cheap and promising
PT
solid base oxide catalyst was synthesized from chicken eggshell by calcination at 900°C forming catalyst eggshells (CES) and was impregnated with the nanomagnetic material (Fe3O4) to obtain
CE
Fe3O4 loaded catalytic eggshell (CES-Fe3O4). Fe3O4 nanomaterials were synthesized by coprecipitation method and were loaded in catalytic eggshell by sonication, for better recovery of
AC
the catalyst after transesterification process. CES-Fe3O4 material was characterized by Thermogravimetric analysis, X-ray diffraction, Fourier Transmission Infrared Spectroscopy, Vibrating-sample magnetometer, Brunauer-Emmer-Teller, Dynamic light scattering, Scanning electron microscopy. Biodiesel was synthesized by transesterification of Pongamia pinnatta raw oil with 1:12 oil to methanol molar ratio and 2 wt% catalyst loading for 2 hours at a temperature of 65°C and yield were compared.
The reusability of the catalyst was studied by the
transesterification of the raw oil and its catalytic activity was found to be retained up to 7 cycles with a yield of 98%.
ACCEPTED MANUSCRIPT Keywords: Catalyst; Biodiesel; nanoparticles; Fe3O4; Impregnation; Transesterification 1. INTRODUCTION The demand rate of non-renewable energy sources like petroleum, coals, natural gases etc. is increasing day by day which leads to scarcity of these fuels [1]. Apart from ever-growing prices of petroleum-based fuels, the harmful exhaust emissions from automobiles directly affecting
T
human health and the environment are of great concern [2]. Hence research is now being directed
IP
in the quest of alternative, renewable and eco-friendly fuels for satisfying the energy demand.
CR
Biodiesel has drawn unique consideration as a potential alternative fuel for current oil-based non-renewable energy sources [3]. Biodiesel is a renewable alternative to diesel, which mainly
US
comprises of mono-alkyl esters of unsaturated fatty acid and also has comparable physical properties of diesel, with unique advantages of being renewable and biodegradable with nontoxic
AN
emissions [4 -7]. Biodiesel is generally produced by transesterification of vegetable oils or animal fats using short-chain alcohols like methanol and ethanol in the presence of catalysts. In
M
the initial step of transesterification, triglyceride gets converted to diglyceride, followed by the conversion of subsequent higher glyceride to lower glyceride and then to glycerol, yielding a
ED
methyl ester molecule from each glyceride [8]. Different types of alcohols such as methanol, ethanol, propanol, and butanol are being used for the biodiesel synthesis. During the reaction,
PT
when methanol is utilized as a reactant, unsaturated fatty acid methyl ester blend (FAME) is obtained whereas, in the presence of ethanol unsaturated fatty acid ethyl esters blend (FAEE) is
CE
obtained [9-12].
The catalyst used for the biodiesel synthesis can be broadly classified into homogeneous and
AC
heterogeneous catalysts. The normal catalyst for the transesterification procedure of vegetable oils is a homogeneous base catalyst, for example, sodium hydroxide (NaOH), potassium hydroxide (KOH) sodium methoxide (NaOCH3) and so forth. The main problems with the use of a homogeneous catalyst are the lack of reusability and formation of soap via saponification reaction, which consumes the catalyst, thus reducing the biodiesel yield while making the purification steps more complicated [13]. Homogeneous acid catalysts like sulphuric acid lead to serious environmental and corrosion problems [14-17]. Consequently, the development of strong heterogeneous catalysts has recently gained much attention owing to their advantage of reusability, without any environmental impacts.
Solid catalysts are generally recovered by
ACCEPTED MANUSCRIPT centrifuging or filtering through the membrane but consumes time and energy. Separation of the catalyst with the aid of magnetic field helps to recover the catalyst and increase the number of cycles for transesterification and also has much potential for industrial applications [18-24]. A wide range of heterogeneous catalysts has been investigated by various researchers. Among them, calcium oxide (CaO) and hydroxyapatite from solid waste like waste eggshells, shells and
T
waste animal bones have received much interest due to their mild reaction condition, relatively
IP
cheap and lower impact on the environment [4,6,7,8,10,12,15,22,24]. Eggshell shows high
CR
thermal stability, relatively low density and phase continuity as compared to calcium carbonate (CaCO3). In addition, the porous structure of eggshell provides high surface area as compared to artificial materials. The waste eggshell based catalysts demonstrated reasonable performance
US
even though high catalyst loading and high methanol/oil ratio are required. The eggshell based catalyst can be made reusable for transesterification by loading it with Fe3O4 nanoparticles,
AN
making it magnetic in nature [7]. Monica et. al. has reported that supporting materials such as Fe3O4 for the catalyst CaO reduces the problem of the formation of high viscous glycerin due to
M
the presence of lattice oxygen on the surface of the catalyst. The addition of Fe3O4 simplifies the process of separation with the application of an external magnetic field [25].
Iron oxide
ED
nanoparticles such as magnetite (Fe3O4) has drawn much attention in recent years due to their potential applications in magnetic media, catalysis, color imaging, biomedicine etc. Fe3O4 has
PT
been widely used as a catalyst in the field of photocatalysis, biocatalysis and phase transfer catalysis etc. [7,16,17,19]. Han et. al. reported the use of KF/CaO-Fe3O4 as a catalyst for the
CE
transesterification. The loading of Fe3O4 nanoparticles in eggshell based catalyst not only help in the recovery of the catalyst but also enhance the surface area and hence the biodiesel yield [19].
AC
Xie et. al. has reported Fe3O4 as a biocatalyst by treating magnetic Fe3O4 nanoparticles with (3aminopropyl) triethoxysilane for the conversion of soybean oil [3]. Chakraborty et. al. used hydroxyapatite impregnated with Antimony (III) chloride as a heterogeneous catalyst, synthesized by the calcination of pork bone at 500oC [12]. The impregnation of the supporting catalyst was done by magnetic stirring. Nisar et. al. synthesized heterogeneous catalyst by the calcination of animal bone at a temperature of 1100oC. [8]. Wei et. al. and Savaliya et. al. synthesized calcium oxide as the catalyst for the transesterification by the calcination of eggshell at a temperature in the range 900 - 1000oC [4,6].
ACCEPTED MANUSCRIPT Recent studies show the potential of eggshell based heterogeneous catalyst for transesterification, owing to its low production cost and high basicity. In this present work, we report a novel method of using waste chicken eggshells loaded with Fe3O4 nanoparticles as a reusable heterogeneous catalyst for the transesterification. Fe3O4 nanomaterials were synthesized by coprecipitation method and were loaded in catalytic eggshell by sonication. Biodiesel was synthesized by conventional transesterification method with methanol recovery setup. The effect
T
of parameters such as molar ratio, time, temperature and loading of catalyst was studied. The
IP
synthesized methyl ester was analyzed using gas chromatography-mass spectrometry [GC-MS]
CR
to evaluate the yield and purity. XRD data was refined by using Rietveld refinement software and quantified the amount of metal hydroxide Ca(OH)2 and metal carbonate CaCO3 conversion
2.1.
AN
2. MATERIALS AND METHODOLOGY
US
during the formation CES-Fe3O4, which has not been reported earlier.
Synthesis of Ferric oxide (Fe3O4) nanoparticles
M
Ferric oxide nanoparticles were synthesized by co-precipitation method. 1M of ferrous sulphate (FeSO4.7H2O) and ferric sulphate heptahydrate (Fe2(SO4)3.7H2O) were mixed in 60 ml of
ED
deionized (DI) water and sonicated for 30 minutes while maintaining the temperature at 65⁰C. Ammonia (NH3) solution was added drop by drop to the solution till the pH reaches 12, finally
PT
forming a black precipitate. Ferric oxide nanoparticles were removed by applying an external magnetic field and were washed several times with DI water until the pH drops to 7. The
CE
material was dried at 70⁰C for 12 hours to obtain ferric oxide nanoparticles.
AC
2.2. Preparation of CES-Fe3O4 based heterogeneous catalyst. Eggshells of chicken were collected from different hotels. The eggshells were washed few times with DI water to remove the impurities and dried at 100⁰C in an oven. The dried eggshell was crushed and grounded to fine powder, followed by calcination in a furnace under atmospheric conditions at different temperatures (500-900⁰C) for 4 hours [4]. CaCO3 is converted to CaO by calcination and the eggshell powder obtained after the calcination was stored in a desiccator for 24 hours, to avoid catalytic poisoning due to contact with air [6]. For the preparation of Fe3O4 loaded eggshell based catalyst, 3g of CaO and 1-5wt% of Fe3O4 nanoparticles were taken in 30
ACCEPTED MANUSCRIPT ml and 20 ml of DI water, respectively and mixed by means of magnetic stirrer followed by ultrasonication for 10 hours, thus loading the Fe3O4 nanoparticles in catalyst eggshells. The solution was dried for 12 hours in a hot air oven followed by calcination for 4 hours at 600°C. The sample was grounded into a fine powder and stored in a vacuum desiccator. 2.3. Characterization
T
The calcined egg shells were characterized by Thermogravimetric analysis (TGA), X-ray
IP
diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy
CR
(TEM), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), Vibrating Sample Magnetometer (VSM). TGA (Perkin Elmer) experiments were carried out
US
under nitrogen atmosphere in the temperature range 100 to 1000°C with a heating rate of 10°C/min. X-ray diffraction patterns were obtained using X-ray diffractometer (Rigaku Miniflex
AN
600) and Rietveld refinement method was used for refining the XRD data. The refinement of XRD data was done under slow scanning of 0.02 degree stepping and Fullprof suite program was Scanning electron microscopy (Hitachi, SU6600) and
M
used for the refinement process.
Transmission electron microscopy (Philips Tecnai G2 F20) analysis of the catalyst was done to
ED
obtain the size and morphology. FT-IR spectroscopy was performed in the wavelength range 400-4000 cm-1. The magnetization curve properties of the samples were studied using a vibrating
PT
sample magnetometer (VSM, Lakeshore VSM 7410) at room temperature. The specific surface area of the prepared catalyst samples was characterized by Surface area analyzer. (Belsorp max,
CE
Microtrac Belcorp). The average size of the materials was measured by means of DLS (Malvern Nano ZS) The fatty acid profile of Pongamia oil, both before and after trans esterification was
AC
obtained using gas chromatography-mass spectrometry (GC-MS) (JEOL GC MATE II). 2.4. Transesterification Pongamia pinnata oil was washed with hot water and filtered thoroughly to remove the undissolved materials. The oil was dried in a dry oven for 24 hours. The acid value of the oil was 6.3 mg NaOH/g with a free fatty acid content of 3.15 wt%. As the free fatty acid content is high, esterification was done before the transesterification reaction in a three-necked flask. In esterification reaction, 100 ml of Pongamia pinnata oil was dried in an oven at 110⁰C for 12 hrs. The oil was blended with 5 (v/w) % of sulphuric acid and the molar ratio of oil and methanol
ACCEPTED MANUSCRIPT was fixed as 1:6. [15]. The reaction was performed for 1 hour at 65°C and the speed of the mechanical stirrer was set at 600 rpm. The reaction mixture was transferred to a separating funnel on completion of the reaction. Esterified oil was used for transesterification and CESFe3O4 powder was used as a heterogeneous catalyst while optimizing the parameters. The fatty acid composition of the biodiesel synthesized from raw Pongamia pinnata was
IP
T
determined by using Gas Chromatography with Mass spectrometer (JEOL GC MATE II). The
MS data.
CR
retention time and the percentage of relative abundance of fatty acid were obtained from the GCThe area of the peaks in the GC-MS data was used for the estimation of FAME
(∑ 𝐴)−𝐴SI 𝐴SI
×
𝐶SI ×𝑉SI 𝑤
× 100
(1)
AN
FAME =
US
conversion [8, 12, 15, 22], as follows:
where ∑ 𝐴 denotes the total peaks area, 𝐴𝑆𝐼 denotes peak area of methyl heptadeconoate (internal
M
standard), 𝐶SI is the concentration of methyl heptadeconoate (mg/ml), 𝑉SI is the volume of internal standard solution used (ml) and w is the weight of biodiesel sample (mg). 𝑊Biodiesel × FAME × 100 % 𝑊Raw oil
(2)
PT
Yield =
ED
The percentage yield is obtained from FAME as follows:
CE
where 𝑊Biodiesel the weight of biodiesel is produced and 𝑊Raw oil is the weight of raw oil (Pongamia pinnata) used.
3.1.
AC
3. RESULT AND DISCUSSIONS Catalyst characterization
The thermal stability of the calcined eggshell was studied by thermogravimetric analysis and is shown in Fig 1 (a). TGA results show weight loss in the temperature range of 300°C - 400°C and above 800°C, the weight of the sample remains constant. The eggshell mainly contains CaCO3 and transformation of the CaCO3 to CaO occurs at a temperature more than 800°C [4, 6]. Hence
ACCEPTED MANUSCRIPT calcination temperature of eggshell was fixed at 900°C to obtain CaO catalyst from the waste eggshell. FTIR spectrum in Fig.1 (b) of eggshell shows that most of the peaks are in the range 1444 cm-1, 874 cm-1, 549 cm-1 and 461 cm-1 which corresponds to the existence of asymmetric stretch, out of the plane bend and in-plane bend of the CES-Fe3O4, respectively [26-28]. CaO catalyst was
T
synthesized from chicken eggshell and its absorption band peak is less than 1064 cm-1. The
IP
eggshells on calcination, loose carbonate due to the decomposition of CaCO3 to CaO, which results in the decrease in the mass of the functional group attached to the CO3- ions accordingly,
CR
diminishing the intensity of CaCO3 peaks. A new peak around 3638 cm-1 corresponding to OHstretching vibration and bending hydroxyl group was also observed in the FTIR spectra of the
CE
PT
ED
M
AN
[10,16,26].
OH- groups in calcium hydroxide, Ca(OH)2
US
calcined eggshells, which corresponds to the
AC
Fig1 (a) TGA of CES (b) FT-IR spectrum of CES-Fe3O4
Fig 2 (a) shows the magnetic hysteresis of the Fe3O4 particles and magnetic composite catalysts measured at room temperature by VSM. Fe3O4 particle exhibits superparamagnetic behavior and the saturation magnetization is around 29.852 emu [7,17,19]. The coercivity, sensitivity, and retentivity were found to be 16.599G, -2.6000emu and 542.80 emu, respectively. CES-Fe3O4 particles exhibit comparatively low superparamagnetic behavior with saturation magnetization around 19.465 emu [19]. The coercivity, sensitivity, and retentivity of CES-Fe3O4 particles were found to be 14.621G, -2.6000 emu and 318.77 emu respectively. However, after the tenth cycle of transesterification with CES-Fe3O4 particles as a catalyst, it exhibits a low superparamagnetic
ACCEPTED MANUSCRIPT behavior with a magnetization around 1.2390 emu as seen in Fig 2 (a). The corresponding coercivity, sensitivity, and retentivity were found to be 18.7686G, -2.6000emu and 542.80 emu, respectively. The magnetic composite catalyst can be recovered with the aid of a magnetic field [29]. The surface area and pore size of CES and CES–Fe3O4 based heterogeneous catalysts were measured by sorption BET method. Fig.2 (b) shows the graphics isotherms of adsorptiondesorption of CES and CES-Fe3O4 based catalysts. The surface area for CES and CES-Fe3O4
T
materials was found to be 7.026 m2/g and 25.618 m2/g, respectively and the pore volume
IP
estimated for these samples was 0.0106 cc/g and 0.0956 cc/g respectively. Pore distribution was
CR
found to be high for CES- Fe3O4 based catalyst, with a pore size of 14.929 nm, which is classified as mesoporous type [14]. The isotherm graph of CES and CES- Fe3O4 shows that it
US
belongs to Type IV of the isotherm, attributing to monolayer - multilayer adsorption [30-32]. The area of the hysteresis loop formed between adsorption and desorption curve in Fig 2(b) indicates of the CES-Fe3O4 catalyst is better as compared to CES catalyst due
AN
that the catalytic behavior
to increase in the surface area owing to the formation of flakes and rough sheets as shown in the
AC
CE
PT
ED
M
TEM image Fig. 4 (b)
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
due xi
de-
M
oxiFig 2. (a)VSM image of Fe3O4 and CES-Fe3O4 (b) Curves of adsorption-desorption isotherm
ED
of CES and CES- Fe3O4(c) Size distribution of CES and CES-Fe3O4 The average size of the CES and CES-Fe3O4 samples measured by DLS was found to be 2612
PT
nm and 1629 nm respectively, as shown in Fig 2 (c). The smaller size was observed for CESFe3O4 sample, due to continuous sonication for 10 hours during the preparation of
CE
nanocomposite catalyst. The single peak in the size distribution of CES-Fe3O4 sample confirms the presence of uniform size particles whereas the two peaks for the CES sample is due to the
AC
presence of different sized particles. Fig 3 (a) shows the SEM images of the raw eggshell which has an irregular crystal structure. Even though eggshell has an irregular crystal structure, flower petals like structure are formed after calcination as shown in Fig 3 (b). The TEM image of Fe3O4 loaded calcined eggshell after sonication for 10 hours is shown in Fig 4 (b) which confirms the presence of spherical Fe3O4 nanoparticles in the structure of calcined eggshell. SEM image of Fe3O4 loaded calcined eggshell shows rough flake structure in Fig.4 (a). Due to the continuous sonication for 10 hours, the petal structures were converted to flake structure. Fig 4 (c) shows the polycrystalline diffraction patterns in the Selected Area Electron Diffraction (SAED) pattern of CES-Fe3O4 nanoparticles. The identified diffraction planes corresponds to (201), (100), (102),
ACCEPTED MANUSCRIPT (101), (001), (110) and (111) indicating that particles are in crystalline phase [3,7,16,17,19]. These results are consistent with those obtained from XRD analysis, seen in Fig 4 (e). Fig 4 (d) shows the image of catalyst CES-Fe3O4 recovery by using an external magnet. In addition, TEM image reveals that the Fe3O4 sample displays a well-defined crystal lattice stripe with a spacing of 2.82 Å and 4.92 Å corresponding to the (220) and (001) planes respectively, as shown in Fig 4 (f) [3]. The energy disperses spectroscopy results (Fig 4 (g)) confirms the presence of Iron (Fe),
T
Oxygen (O), Calcium (Ca) elements in the prepared sample and Carbon (C) which could be due
CR
IP
to the formation of CaCO3.
Fig.5 (a). shows the transformation of the catalyst into new phases [3,6,7,19]. The peaks corresponding to angles 17.3°,29.2°,47.4°,72°,84.1°, 33.6°,51.3°,54.6°,62.3°, and 64.2° is clearly
US
visible from Fig 5 (a). The sonication of CaO catalyst in Fe3O4 solution results in the conversion of CaO to Ca(OH)2 and also to CaCO3 phase loaded with Fe3O4. CaO catalyst being unstable
AN
and hygroscopic in nature tends to convert to a stable form. The formation Ca(OH)2 help to improve the yield, even though the drawback for the formation of hydroxide compound has been
M
reported [19]. Han et. al. has reported the benefit of formation of hydroxide which increases the biodiesel yield. The water molecules adsorbed initially on the metal oxide catalyst surface forms
ED
metal hydroxide (OH-) which help to accept one proton from methanol to generate methoxide (CH3O-) [19]. The high conversion of oil to methyl ester observed in the present work could be
PT
due to the formation of excess metal hydroxide Ca(OH)2 of 94%, as per the Rietveld refinement
AC
CE
data.
Fig 3. SEM image of (a) raw eggshell (b) CES after calcination at 900°C
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
Fig 4. (a) SEM image of CES-Fe3O4 (b) TEM image of CES- Fe3O4 (c) Pattern of CES-Fe3O4
M
nanoparticles (d) Recovery of catalyst CES-Fe3O4 by using an external magnet (e) XRD data of
ED
CES-Fe3O4 (f) Surface morphology and SAED (g) EDS spectra of CES- Fe3O4 The XRD pattern shows the confirmation of CES-Fe3O4 and was further studied by using the
PT
Rietveld refinement method to determine the formation of Ca(OH)2 and CaCO3. The detailed structural properties of prepared Ca(OH)2 was obtained through Rietveld refinement of the XRD
CE
pattern, as shown in Fig 5 (b). The refined XRD data confirms that the prepared sample contains 94% percentage of Ca(OH)2 phase and 6% of CaCO3 phase. Further, structural details of
AC
individual phases were also extracted from the refinement output. The presence of a higher percentage of hydroxide phase in the material results in the better conversion of oil to methyl ester.
CR
IP
T
ACCEPTED MANUSCRIPT
Fig 5. (a) XRD pattern of the CES-Fe3O4 with confirmation phases (b) Refinement data
Transesterification reaction
AN
3.2.
US
of CES-Fe3O4
The transesterification of Pongamia pinnata oil was done with CES-Fe3O4 as a catalyst. Various
M
parameters affecting the transesterification of the biodiesel includes (i) reaction temperature (ii) reaction time (iii) catalyst loading (iv) oil to methanol ratio. The parameters were optimized to
ED
obtain the maximum yield of biodiesel based on one-factor approach and the details are
PT
presented here. Temperature
CE
The effect of reaction temperature on transesterification of Pongamia pinnata oil was studied and results are shown in Fig 6 (a). FAME yield was found to be increased with increase in
AC
temperature, and achieved a maximum value at 65°C, followed by a decrease in the yield [4]. The increase in the yield with the temperature could be due to the high mobility of molecules with increase in temperature resulting in high reaction rate [33]. However as the reaction temperature goes beyond 70°C, which is the boiling temperature of methanol, methanol evaporates decreasing the biodiesel yield. Hence the reaction temperature was fixed at 65°C.
ED
M
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
PT
Fig 6. Variation of biodiesel yield with (a) reaction temperature (b) reaction time (c) loading of
Reaction time
CE
catalyst (d) oil to molar ratio.
The effect of reaction temperature on the biodiesel yield was studied and the results are shown in
AC
Fig 6 (b). The biodiesel yield was found to increase with an increase in the reaction time, with a maximum yield of 98% attained for a reaction time of 120 minutes, followed by a decrease in yield with time [6]. The reaction could have achieved equilibrium at the end of 120 minutes and afterward the shifting of the reaction occurs in the reverse direction, leading to the soap formation [34]. Hence the reaction time was fixed at 120 minutes. Catalyst loading
ACCEPTED MANUSCRIPT The catalyst loading directly affects the biodiesel yield in a transesterification reaction. The high Free Fatty Acid in the feedstock, results in the soap formation, influencing the separation process which limits the FAME yield. The variation of the yield with the catalyst loading is shown in Fig 6 (c). The biodiesel yield was found to increase with an increase in the catalyst loading, up to 2 wt% loading with a biodiesel yield of 98 %. However, a decrease in the yield was observed with further increase in the concentration of catalyst. An excess amount of catalyst adversely affects
T
the mixing of methanol, oil, and catalyst leading to phase separation [35]. Hence in the present
CR
IP
study, catalytic loading was fixed as 2 wt%. Oil to Methanol molar ratio
US
Oil to methanol molar ratio directly affects the biodiesel yield. The variation of the yield with the oil: methanol ratio is shown in Fig 6 (d). As the methanol to oil ratio increases from 1:3 to 1:12
AN
the biodiesel yield was found to increase from 56 to 98%, with further decrease in the yield [27]. Normally the excess methanol favors the shift in the equilibrium, to achieve high biodiesel yield
M
[36]. However, as the methanol concentration increases, the contents of catalyst and reactants are dissolved by methanol, which may inhibit the reaction thus reducing the biodiesel yield. The oil
ED
to methanol molar ratio was fixed at 1:12.
PT
3.3. Yield comparison
The transesterification of Pongamia pinnata oil was done by using raw animal bone, CES and
CE
CES-Fe3O4 as a catalyst, with the optimized parameters and yield were compared as shown in Fig 7 (a). The improved catalytic behavior of CES-Fe3O4 treated sample is mainly due to the
AC
increase in surface area and pore volume due to the layered structure as mentioned earlier [26,31]. The raw eggshell cannot be used as a catalyst as it does not help in the conversion of methanol to methoxide, which aids in the conversion of triglycerides to methyl ester. The economic feasibility of biodiesel production at large scale depends on the reusability and stability of the calcium-based catalyst. The reusability of the calcined chicken eggshell (900°C) was studied by carrying out the transesterification under the optimized condition, with oil to methanol ratio of 1:12, catalyst loading of 2 wt.%, a reaction temperature of 65°C and response time of 120 min. Catalysts recovered after the transesterification reaction was washed and reused and yield obtained in each cycle was compared. Fig 7 (b) shows the variation of biodiesel yield
ACCEPTED MANUSCRIPT with the cycles of transesterification. The biodiesel yield of 98% was obtained initially which was found to be consistent until the 7th cycle of the transesterification reaction, followed by a decrease in the yield. The decrease in the yield is mainly due to blockage of catalyst pores which
AN
US
CR
IP
T
further reduces the adsorption and desorption of the reactants.
M
Fig 7. (a) Biodiesel yield comparison (b) Reusability of the CES-Fe3O4
ED
Table 1. GC- MS data of raw oil; Pongamia pinnata oil
AC
CE
PT
Table 2. GC- MS data of Pongamia pinnata oil based Methyl Ester
AC
CE
PT
ED
M
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
Fig 8. GC-MS chromatogram of (a) raw Pongamia pinnata oil (b) biodiesel synthesized from Pongamiapinnata oil.
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
M
Fig 9. Adsorption and desorption on the active site of the heterogeneous catalyst -schematic
ED
The fatty acid composition of Pongamia pinnata oil was analyzed by using gas chromatographymass spectra. Table.1 and Table 2 shows the GC-MS data of Pongamia pinnata oil and Pongamia
PT
pinnata oil biodiesel respectively, in which retention time and percentage of relative abundance of fatty acid are shown. Different peaks in GC-MS chromatogram represent the presence of
CE
methyl esters and the maximum peak indicates the presence of Octadecenoic Acid (43.94%) methyl ester and a minimum of the presence of Margaric acid (0.09%). Fig 8 (b). shows that the -
C19 is maximum, while the
AC
presence of compounds with carbon atoms in the range C17
compounds with carbon atoms in the range C15-C16 is minimum. GC-MS results also establish the successful transformation of palm oil into biodiesel [15,22]. From GC-MS chromatogram Fig 8 (a), 7 major peaks of various fatty acids were visible in the case of raw Pongamia Pinnata oil whereas 13 major peaks were visible in the case of Pongamia pinnata oil based biodiesel. The increase in the number of peaks of methyl esters could be due to the conversion of raw Pongamia pinnata to methyl ester (biodiesel), shown in Fig 8 (b) [37]. The abundance data in Fig.8 (b) is higher than that in Fig.8 (a), which shows good conversion of raw oil to methyl ester (biodiesel)
ACCEPTED MANUSCRIPT [38]. Table 3. shows the comparison of present work with that of similar works on eggshells/shells based heterogeneous catalyst, reported earlier. Table 3
T
Comparison of catalytic activity with reported eggshell based heterogeneous catalysts.
IP
4. Conclusions
CR
In summary, we have demonstrated a simple route for the synthesis of magnetic recoverable CES-Fe3O4 cheap catalyst from waste eggshells. The solid base oxide catalyst was synthesized
US
by calcination of chicken eggshell at 900°C and was loaded with the nanomagnetic material (Fe3O4). Fe3O4 nanomaterials were synthesized by co-precipitation method and were loaded in
AN
calcined eggshell by sonication. The calcination followed by sonication for 10 hours results in the formation of flake-like structures with enhanced surface area. The surface area of calcined
M
chicken eggshell was found to be increased from 7.026 m2/g to 25.618m2/g with the loading of Fe3O4 nanoparticles. The transesterification of Pongamia pinnata oil was done using Fe3O4 loaded The sonication of calcined
ED
calcined chicken eggshell and the parameters were optimized.
chicken eggshell in Fe3O4 solution results in the conversion of CaO to Ca(OH)2 which aids in the
PT
enhancement of the biodiesel yield. The reusability of the catalyst was studied by performing the transesterification using the same catalyst for 10 cycles and the yield was found to be slightly
CE
decreased after the 7th cycle, which could be due to the blockage of catalyst pores, reducing adsorption and desorption of the reactants.
[1]
AC
REFERENCES:
I.M. Atadashi, M.K. Aroua, A.R. Abdul Aziz, N.M.N. Sulaiman, The effects of catalysts in biodiesel production: A review, J. Ind. Eng. Chem. 19 (2013) 14–26.
[2]
N. Mansir, S.H. Teo, I. Rabiu, Y.H. Taufiq-Yap, Effective biodiesel synthesis from waste cooking oil and biomass residue solid green catalyst, Chem. Eng. J. 347 (2018) 137–144.
[3]
W. Xie, N. Ma, Immobilized Lipase on Fe3O4 Nanoparticles as biocatalyst for biodiesel production, Energy and Fuels. 23 (2009) 1347–1353.
ACCEPTED MANUSCRIPT
[4]
Wei Z, Xu C, Li B. Application of waste eggshell as low-cost solid catalyst for biodiesel
V.C. dos Santos, K. Wilson, A.F. Lee, S. Nakagaki, Physicochemical properties of
IP
[5]
T
production. Bioresource Technol. 5 (2009) 2883-2885.
WOx/ZrO2 catalysts for palmitic acid esterification, Appl. Catal. B Environ. 162 (2015)
[6]
CR
75–84.
M.L. Savaliya, M.S. Bhakhar, B.Z. Dholakiya, Cutting cost technology for the preparation
US
of biodiesel using environmentally benign and cheaper catalyst, Catal. Letters. 146 (2016)
[7]
AN
2313–2323.
E. Mosaddegh, F.A. Hosseininasab, A. Hassankhani, Eggshell/Fe3O4 nanocomposite:
M
novel magnetic nanoparticles coated on porous ceramic eggshell waste as an efficient catalyst in the synthesis of 1,8-dioxo-octahydroxanthene, RSC Adv. 5 (2015) 106561–
Nisar J, Razaq R, Farooq M, Iqbal M, Khan RA, Sayed M, et al. Enhanced biodiesel
PT
[8]
ED
106567.
production from Jatropha oil using calcined waste animal bones as catalyst. Renew
[9]
AC
CE
Energy 9 (2017) 101:111.
V.B. Gade, A.K. Rathi, S.B. Bhalekar, J. Tucek, O. Tomanec, R.S. Varma, R. Zboril, S.N. Shelke, M.B. Gawande, Iron-Oxide-supported ultrasmall ZnO nanoparticles: Applications for transesterification, Amidation, and O-Acylation reactions, ACS Sustain. Chem. Eng. 5 (2017) 3314–3320.
[10] S.L. Lee, Y.C. Wong, Y.P. Tan, S.Y. Yew, Transesterification of palm oil to biodiesel by using waste obtuse horn shell-derived CaO catalyst, Energy Convers. Manag. 93 (2015) 282–288.
ACCEPTED MANUSCRIPT [11] S. Luz Martínez, R. Romero, J.C. López, A. Romero, V. Sánchez Mendieta, R. Natividad, Preparation and characterization of CaO nanoparticles/NaX zeolite catalysts for the transesterification of sunflower oil, Ind. Eng. Chem. Res. 50 (2011) 2665–2670. [12] Chakraborty R, Mukhopadhyay P, Kumar B. Optimal biodiesel-additive synthesis under
T
infrared excitation using pork bone supported-Sb catalyst: Engine performance and
IP
emission analyses. Energy Convers. Manag. 126 (2016) 132–141.
CR
[13] S. Semwal, A.K. Arora, R.P. Badoni, D.K. Tuli, Biodiesel production using heterogeneous catalysts, Bioresour. Technol. 102 (2011) 2151–2161.
US
[14] A.F. Lee, K. Wilson, Recent developments in heterogeneous catalysis for the sustainable
AN
production of biodiesel, Catal. Today. 242 (2015) 3–18.
[15] D. Madhu, Y.C. Sharma, Synthesis of a reusable novel catalyst (β-tricalcium phosphate)
M
for biodiesel production from a common Indian tribal feedstock, Resour. Technol. 3 (2017) 144–157.
ED
[16] Y. Liu, J. Chung, Y. Jang, S. Mao, B.M. Kim, Y. Wang, X. Guo, Magnetically recoverable nanoflake-shaped iron oxide/Pt heterogeneous catalysts and their excellent
PT
catalytic performance in the hydrogenation reaction, ACS Appl. Mater. Interfaces. 6
CE
(2014) 1887–1892.
[17] S. Tang, L. Wang, Y. Zhang, S. Li, S. Tian, B. Wang, Study on preparation of
AC
Ca/Al/Fe3O4 magnetic composite solid catalyst and its application in biodiesel transesterification, Fuel Process. Technol. 95 (2012) 84–89. [18] D.Y.C. Leung, X. Wu, M.K.H. Leung, A review on biodiesel production using catalyzed transesterification, Appl. Energy. 87 (2010) 1083–1095. [19] S. Hu, Y. Guan, Y. Wang, H. Han, Nano-magnetic catalyst KF/CaO-Fe3O4 for biodiesel production, Appl. Energy. 88 (2011) 2685–2690. [20] M. Feyzi, L. Norouzi, Preparation and kinetic study of magnetic Ca/Fe3O4@SiO2 nanocatalysts for biodiesel production, Renew. Energy. 94 (2016) 579–586.
ACCEPTED MANUSCRIPT [21] B. jin Xue, J. Luo, F. Zhang, Z. Fang, Biodiesel production from soybean and Jatropha oils by magnetic CaFe2O4-Ca2Fe2O5-based catalyst, Energy. 68 (2014) 584–591. [22] Y.C. Sharma, B. Singh, J. Korstad, Application of an efficient nonconventional heterogeneous catalyst for biodiesel synthesis from pongamia pinnata oil, Energy and Fuels. 24 (2010) 3223–3231. d
T
[23] D. Kumar, A. Ali, Transesteri fi cation of Low-Quality Triglycerides over a Zn/CaO
IP
Heterogeneous Catalyst : Kinetics and Reusability Studies, Energy and Fuels. 27 (2013)
CR
3758–3768.
[24] S.B. Chavan, R.R. Kumbhar, D. Madhu, B. Singh, Y.C. Sharma, Synthesis of biodiesel
US
from Jatropha curcas oil using waste eggshell and study of its fuel properties, RSC Adv. 5
AN
(2015) 63596–63604.
[25] M.C.G. Albuquerque, J. Santamaría-González, J.M. Mérida-Robles, R. Moreno-Tost, E.
M
Rodríguez-Castellón, A. Jiménez-López, D.C.S. Azevedo, C.L. Cavalcante, P. MairelesTorres, MgM (M = Al and Ca) oxides as basic catalysts in transesterification processes,
ED
Appl. Catal. A Gen. 347 (2008) 162–168. [26] Y.C. Sharma, B. Singh, J. Korstad, Latest developments on application of heterogenous
PT
basic catalysts for an efficient and eco friendly synthesis of biodiesel: A review, Fuel. 90
CE
(2011) 1309–1324.
[27] A.P.S. Chouhan, A.K. Sarma, Modern heterogeneous catalysts for biodiesel production: A
AC
comprehensive review, Renew. Sustain. Energy Rev. 15 (2011) 4378–4399. [28] C. Liu, P. Lv, Z. Yuan, F. Yan, W. Luo, The nanometer magnetic solid base catalyst for production of biodiesel, Renew. Energy. 35 (2010) 1531–1536. [29] S. Chen, R. Si, E. Taylor, J. Janzen, J. Chen, Synthesis of Pd/Fe3O4 hybrid nanocatalysts with controllable interface and enhanced catalytic activities for CO oxidation, J. Phys. Chem. C. 116 (2012) 12969–12976. [30] A.F. Lee, J.A. Bennett, J.C. Manayil, K. Wilson, Heterogeneous catalysis for sustainable biodiesel production via esterification and transesterification, Chem. Soc. Rev. 43 (2014)
ACCEPTED MANUSCRIPT 7887–7916.
[31] D.R. Vardon, B.R. Moser, W. Zheng, K. Witkin, R.L. Evangelista, T.J. Strathmann, K. Rajagopalan, B.K. Sharma, Complete utilization of spent coffee grounds to produce
IP
T
biodiesel, bio-oil, and biochar, ACS Sustain. Chem. Eng. 1 (2013) 1286–1294.
CR
[32] G. Corro, N. Sánchez, U. Pal, F. Bañuelos, Biodiesel production from waste frying oil using waste animal bone and solar heat, Waste Manag. 47 (2016) 105–113.
US
[33] I.B. Banković-Ilić, M.R. Miladinović, O.S. Stamenković, V.B. Veljković, Application of nano CaO–based catalysts in biodiesel synthesis, Renew. Sustain. Energy Rev. 72 (2017)
AN
746–760.
[34] Ara; Nunes, R. C. D. R.; De Moura, C. V. R.; De Moura; Dos Santos junior, J. R.,
M
Synthesis and characterization of beef tallow biodiesel, Energy and Fuels. 24 (2010)
ED
4476–4480.
[35] I.M. Atadashi, M.K. Aroua, A.A. Aziz, Biodiesel separation and purification: A review,
PT
Renew. Energy. 36 (2011) 437–443.
CE
[36] M. Balat, Potential alternatives to edible oils for biodiesel production - A review of current work, Energy Convers. Manag. 52 (2011) 1479–1492. S. Chellappan, V. Nair, V. Sajith, K. Aparna, Synthesis optimization and characterization
AC
[37]
of biochar based catalyst from saw dust for stimultaneous eterification and transesterification. Chinese J. Chem. Eng. (2018) 1082-1092. doi: [38]
Chellappan S, Nair V, Sajith V, Aparna K. Experimental validation of biochar based green bronsted acid catalysts for simultaneous esterification and transesterification in biodiesel production. Bioresour Technol Reports 2 (2018) 38–44.
ACCEPTED MANUSCRIPT Table 1. GC- MS data of raw oil; Pongamia pinnata oil Sl.No.
Retention time (min)
Fatty Acid Profile
Composition(%)
25.775
Palmitic Acid
11.33
2
30.141
Stearic Acid
6.01
3
30.452
Oleic Acid
44.45
4
31.343
Linoleic Acid
17.10
5
32.624
Linolenic Acid
2.52
6
34.145
Arachidic Acid
7
34.420
Eicosenoic Acid
8
34.729
Behenic Acid
9
37.727
Lignoceric Acid
IP CR
US
AN M ED PT CE AC
T
1
1.55 2.14
10.15 4.76
ACCEPTED MANUSCRIPT Table 2. GC- MS data of Pongamia pinnata oil based Methyl Ester Retention time (min)
Fatty Acid Profile
Composition(%)
15.867
Lauric Acid
0.21
2
21.022
Myristic Acid
0.94
3
25.736
Palmitic Acid
37.86
4
26.246
Palmitoleic Acid
0.16
5
27.911
Margaric Acid
6
30.061
Stearic Acid
7
30.446
Octadecenoic Acid
43.94
8
31.380
Linoleic Acid
11.02
9
32.689
Linolenic Acid
0.14
10
34.000
Arachidic Acid
0.45
11
34.349
Behenic Acid
0.19
12
37.721
Lignoceric Acid
0.11
13
41.169
Eicosenoic Acid
0.12
IP
CR
AN M
ED PT CE AC
T
1
US
Sl.No.
0.09 4.76
ACCEPTED MANUSCRIPT
Table 3 Comparison of catalytic activity with reported eggshells based catalysts.
Mode of operation
Eggshells with Fe3O4
12:1
2
65
2
Waste eggshells
9:1
3
65
Eggshells derived
8:1
2.5
65
Fe3O4 with alkali from eggshell
4chlorobenzalde hyde (0.14 g) and dimedone (0.28 g)
1
Waste obtuse horn shell derived catalyst.
12:1
5
Eggshells
8:1
2.5
Waste eggshells
8:1
Referenc es
Conventional
98
This work
Conventional
95
[4]
3
Conventional
99.2
[6]
0.25
Conventional
95
[7]
65
6
Conventional
86.75
[10]
65
2.5
Conventional
95
[22]
65
2.5
Conventional
AN
US
3
M
80
ED PT
CE AC
Biodiesel yield (%)
T
Reaction Time (h)
IP
Reaction conditions Reaction Methanol to oil Catalyst Temperatu ratio (mol) (wt. %) re (ºC)
CR
Waste Shells based base heterogeneous catalyst
2
90
[24]
ED
M
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
AC
CE
PT
Graphical abstract
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Ch. Chingakham, Asha David, V. Sajith PII: DOI: Reference:
S1004-9541(18)31820-2 https://doi.org/10.1016/j.cjche.2019.02.022 CJCHE 1424
To appear in:
Chinese Journal of Chemical Engineering
Received date: Revised date: Accepted date:
4 December 2018 19 January 2019 20 February 2019
Please cite this article as: C. Chingakham, A. David and V. Sajith, Fe3O4 nanoparticles impregnated eggshell as a novel catalyst for enhanced biodiesel production, Chinese Journal of Chemical Engineering, https://doi.org/10.1016/j.cjche.2019.02.022
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Article Fe3O4 nanoparticles impregnated eggshell as a novel catalyst for enhanced biodiesel production
2
Malabar Christian College, Calicut, India
corresponding author email: [email protected]
US
#
IP
School of Nano Science and Technology, National Institute of Technology Calicut, India
CR
1
T
Ch.Chingakham1, Asha David2 and V.Sajith1，*
AN
Abstract
M
Biodiesel is a green fuel which can replace diesel while addressing various issues such as scarcity of hydrocarbon fuels, environmental pollution etc. to an extent. The high production cost
ED
of biodiesel and the recovery of the catalyst after the transesterification process are the major challenges to be addressed in biodiesel production. In the present work, a cheap and promising
PT
solid base oxide catalyst was synthesized from chicken eggshell by calcination at 900°C forming catalyst eggshells (CES) and was impregnated with the nanomagnetic material (Fe3O4) to obtain
CE
Fe3O4 loaded catalytic eggshell (CES-Fe3O4). Fe3O4 nanomaterials were synthesized by coprecipitation method and were loaded in catalytic eggshell by sonication, for better recovery of
AC
the catalyst after transesterification process. CES-Fe3O4 material was characterized by Thermogravimetric analysis, X-ray diffraction, Fourier Transmission Infrared Spectroscopy, Vibrating-sample magnetometer, Brunauer-Emmer-Teller, Dynamic light scattering, Scanning electron microscopy. Biodiesel was synthesized by transesterification of Pongamia pinnatta raw oil with 1:12 oil to methanol molar ratio and 2 wt% catalyst loading for 2 hours at a temperature of 65°C and yield were compared.
The reusability of the catalyst was studied by the
transesterification of the raw oil and its catalytic activity was found to be retained up to 7 cycles with a yield of 98%.
ACCEPTED MANUSCRIPT Keywords: Catalyst; Biodiesel; nanoparticles; Fe3O4; Impregnation; Transesterification 1. INTRODUCTION The demand rate of non-renewable energy sources like petroleum, coals, natural gases etc. is increasing day by day which leads to scarcity of these fuels [1]. Apart from ever-growing prices of petroleum-based fuels, the harmful exhaust emissions from automobiles directly affecting
T
human health and the environment are of great concern [2]. Hence research is now being directed
IP
in the quest of alternative, renewable and eco-friendly fuels for satisfying the energy demand.
CR
Biodiesel has drawn unique consideration as a potential alternative fuel for current oil-based non-renewable energy sources [3]. Biodiesel is a renewable alternative to diesel, which mainly
US
comprises of mono-alkyl esters of unsaturated fatty acid and also has comparable physical properties of diesel, with unique advantages of being renewable and biodegradable with nontoxic
AN
emissions [4 -7]. Biodiesel is generally produced by transesterification of vegetable oils or animal fats using short-chain alcohols like methanol and ethanol in the presence of catalysts. In
M
the initial step of transesterification, triglyceride gets converted to diglyceride, followed by the conversion of subsequent higher glyceride to lower glyceride and then to glycerol, yielding a
ED
methyl ester molecule from each glyceride [8]. Different types of alcohols such as methanol, ethanol, propanol, and butanol are being used for the biodiesel synthesis. During the reaction,
PT
when methanol is utilized as a reactant, unsaturated fatty acid methyl ester blend (FAME) is obtained whereas, in the presence of ethanol unsaturated fatty acid ethyl esters blend (FAEE) is
CE
obtained [9-12].
The catalyst used for the biodiesel synthesis can be broadly classified into homogeneous and
AC
heterogeneous catalysts. The normal catalyst for the transesterification procedure of vegetable oils is a homogeneous base catalyst, for example, sodium hydroxide (NaOH), potassium hydroxide (KOH) sodium methoxide (NaOCH3) and so forth. The main problems with the use of a homogeneous catalyst are the lack of reusability and formation of soap via saponification reaction, which consumes the catalyst, thus reducing the biodiesel yield while making the purification steps more complicated [13]. Homogeneous acid catalysts like sulphuric acid lead to serious environmental and corrosion problems [14-17]. Consequently, the development of strong heterogeneous catalysts has recently gained much attention owing to their advantage of reusability, without any environmental impacts.
Solid catalysts are generally recovered by
ACCEPTED MANUSCRIPT centrifuging or filtering through the membrane but consumes time and energy. Separation of the catalyst with the aid of magnetic field helps to recover the catalyst and increase the number of cycles for transesterification and also has much potential for industrial applications [18-24]. A wide range of heterogeneous catalysts has been investigated by various researchers. Among them, calcium oxide (CaO) and hydroxyapatite from solid waste like waste eggshells, shells and
T
waste animal bones have received much interest due to their mild reaction condition, relatively
IP
cheap and lower impact on the environment [4,6,7,8,10,12,15,22,24]. Eggshell shows high
CR
thermal stability, relatively low density and phase continuity as compared to calcium carbonate (CaCO3). In addition, the porous structure of eggshell provides high surface area as compared to artificial materials. The waste eggshell based catalysts demonstrated reasonable performance
US
even though high catalyst loading and high methanol/oil ratio are required. The eggshell based catalyst can be made reusable for transesterification by loading it with Fe3O4 nanoparticles,
AN
making it magnetic in nature [7]. Monica et. al. has reported that supporting materials such as Fe3O4 for the catalyst CaO reduces the problem of the formation of high viscous glycerin due to
M
the presence of lattice oxygen on the surface of the catalyst. The addition of Fe3O4 simplifies the process of separation with the application of an external magnetic field [25].
Iron oxide
ED
nanoparticles such as magnetite (Fe3O4) has drawn much attention in recent years due to their potential applications in magnetic media, catalysis, color imaging, biomedicine etc. Fe3O4 has
PT
been widely used as a catalyst in the field of photocatalysis, biocatalysis and phase transfer catalysis etc. [7,16,17,19]. Han et. al. reported the use of KF/CaO-Fe3O4 as a catalyst for the
CE
transesterification. The loading of Fe3O4 nanoparticles in eggshell based catalyst not only help in the recovery of the catalyst but also enhance the surface area and hence the biodiesel yield [19].
AC
Xie et. al. has reported Fe3O4 as a biocatalyst by treating magnetic Fe3O4 nanoparticles with (3aminopropyl) triethoxysilane for the conversion of soybean oil [3]. Chakraborty et. al. used hydroxyapatite impregnated with Antimony (III) chloride as a heterogeneous catalyst, synthesized by the calcination of pork bone at 500oC [12]. The impregnation of the supporting catalyst was done by magnetic stirring. Nisar et. al. synthesized heterogeneous catalyst by the calcination of animal bone at a temperature of 1100oC. [8]. Wei et. al. and Savaliya et. al. synthesized calcium oxide as the catalyst for the transesterification by the calcination of eggshell at a temperature in the range 900 - 1000oC [4,6].
ACCEPTED MANUSCRIPT Recent studies show the potential of eggshell based heterogeneous catalyst for transesterification, owing to its low production cost and high basicity. In this present work, we report a novel method of using waste chicken eggshells loaded with Fe3O4 nanoparticles as a reusable heterogeneous catalyst for the transesterification. Fe3O4 nanomaterials were synthesized by coprecipitation method and were loaded in catalytic eggshell by sonication. Biodiesel was synthesized by conventional transesterification method with methanol recovery setup. The effect
T
of parameters such as molar ratio, time, temperature and loading of catalyst was studied. The
IP
synthesized methyl ester was analyzed using gas chromatography-mass spectrometry [GC-MS]
CR
to evaluate the yield and purity. XRD data was refined by using Rietveld refinement software and quantified the amount of metal hydroxide Ca(OH)2 and metal carbonate CaCO3 conversion
2.1.
AN
2. MATERIALS AND METHODOLOGY
US
during the formation CES-Fe3O4, which has not been reported earlier.
Synthesis of Ferric oxide (Fe3O4) nanoparticles
M
Ferric oxide nanoparticles were synthesized by co-precipitation method. 1M of ferrous sulphate (FeSO4.7H2O) and ferric sulphate heptahydrate (Fe2(SO4)3.7H2O) were mixed in 60 ml of
ED
deionized (DI) water and sonicated for 30 minutes while maintaining the temperature at 65⁰C. Ammonia (NH3) solution was added drop by drop to the solution till the pH reaches 12, finally
PT
forming a black precipitate. Ferric oxide nanoparticles were removed by applying an external magnetic field and were washed several times with DI water until the pH drops to 7. The
CE
material was dried at 70⁰C for 12 hours to obtain ferric oxide nanoparticles.
AC
2.2. Preparation of CES-Fe3O4 based heterogeneous catalyst. Eggshells of chicken were collected from different hotels. The eggshells were washed few times with DI water to remove the impurities and dried at 100⁰C in an oven. The dried eggshell was crushed and grounded to fine powder, followed by calcination in a furnace under atmospheric conditions at different temperatures (500-900⁰C) for 4 hours [4]. CaCO3 is converted to CaO by calcination and the eggshell powder obtained after the calcination was stored in a desiccator for 24 hours, to avoid catalytic poisoning due to contact with air [6]. For the preparation of Fe3O4 loaded eggshell based catalyst, 3g of CaO and 1-5wt% of Fe3O4 nanoparticles were taken in 30
ACCEPTED MANUSCRIPT ml and 20 ml of DI water, respectively and mixed by means of magnetic stirrer followed by ultrasonication for 10 hours, thus loading the Fe3O4 nanoparticles in catalyst eggshells. The solution was dried for 12 hours in a hot air oven followed by calcination for 4 hours at 600°C. The sample was grounded into a fine powder and stored in a vacuum desiccator. 2.3. Characterization
T
The calcined egg shells were characterized by Thermogravimetric analysis (TGA), X-ray
IP
diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy
CR
(TEM), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), Vibrating Sample Magnetometer (VSM). TGA (Perkin Elmer) experiments were carried out
US
under nitrogen atmosphere in the temperature range 100 to 1000°C with a heating rate of 10°C/min. X-ray diffraction patterns were obtained using X-ray diffractometer (Rigaku Miniflex
AN
600) and Rietveld refinement method was used for refining the XRD data. The refinement of XRD data was done under slow scanning of 0.02 degree stepping and Fullprof suite program was Scanning electron microscopy (Hitachi, SU6600) and
M
used for the refinement process.
Transmission electron microscopy (Philips Tecnai G2 F20) analysis of the catalyst was done to
ED
obtain the size and morphology. FT-IR spectroscopy was performed in the wavelength range 400-4000 cm-1. The magnetization curve properties of the samples were studied using a vibrating
PT
sample magnetometer (VSM, Lakeshore VSM 7410) at room temperature. The specific surface area of the prepared catalyst samples was characterized by Surface area analyzer. (Belsorp max,
CE
Microtrac Belcorp). The average size of the materials was measured by means of DLS (Malvern Nano ZS) The fatty acid profile of Pongamia oil, both before and after trans esterification was
AC
obtained using gas chromatography-mass spectrometry (GC-MS) (JEOL GC MATE II). 2.4. Transesterification Pongamia pinnata oil was washed with hot water and filtered thoroughly to remove the undissolved materials. The oil was dried in a dry oven for 24 hours. The acid value of the oil was 6.3 mg NaOH/g with a free fatty acid content of 3.15 wt%. As the free fatty acid content is high, esterification was done before the transesterification reaction in a three-necked flask. In esterification reaction, 100 ml of Pongamia pinnata oil was dried in an oven at 110⁰C for 12 hrs. The oil was blended with 5 (v/w) % of sulphuric acid and the molar ratio of oil and methanol
ACCEPTED MANUSCRIPT was fixed as 1:6. [15]. The reaction was performed for 1 hour at 65°C and the speed of the mechanical stirrer was set at 600 rpm. The reaction mixture was transferred to a separating funnel on completion of the reaction. Esterified oil was used for transesterification and CESFe3O4 powder was used as a heterogeneous catalyst while optimizing the parameters. The fatty acid composition of the biodiesel synthesized from raw Pongamia pinnata was
IP
T
determined by using Gas Chromatography with Mass spectrometer (JEOL GC MATE II). The
MS data.
CR
retention time and the percentage of relative abundance of fatty acid were obtained from the GCThe area of the peaks in the GC-MS data was used for the estimation of FAME
(∑ 𝐴)−𝐴SI 𝐴SI
×
𝐶SI ×𝑉SI 𝑤
× 100
(1)
AN
FAME =
US
conversion [8, 12, 15, 22], as follows:
where ∑ 𝐴 denotes the total peaks area, 𝐴𝑆𝐼 denotes peak area of methyl heptadeconoate (internal
M
standard), 𝐶SI is the concentration of methyl heptadeconoate (mg/ml), 𝑉SI is the volume of internal standard solution used (ml) and w is the weight of biodiesel sample (mg). 𝑊Biodiesel × FAME × 100 % 𝑊Raw oil
(2)
PT
Yield =
ED
The percentage yield is obtained from FAME as follows:
CE
where 𝑊Biodiesel the weight of biodiesel is produced and 𝑊Raw oil is the weight of raw oil (Pongamia pinnata) used.
3.1.
AC
3. RESULT AND DISCUSSIONS Catalyst characterization
The thermal stability of the calcined eggshell was studied by thermogravimetric analysis and is shown in Fig 1 (a). TGA results show weight loss in the temperature range of 300°C - 400°C and above 800°C, the weight of the sample remains constant. The eggshell mainly contains CaCO3 and transformation of the CaCO3 to CaO occurs at a temperature more than 800°C [4, 6]. Hence
ACCEPTED MANUSCRIPT calcination temperature of eggshell was fixed at 900°C to obtain CaO catalyst from the waste eggshell. FTIR spectrum in Fig.1 (b) of eggshell shows that most of the peaks are in the range 1444 cm-1, 874 cm-1, 549 cm-1 and 461 cm-1 which corresponds to the existence of asymmetric stretch, out of the plane bend and in-plane bend of the CES-Fe3O4, respectively [26-28]. CaO catalyst was
T
synthesized from chicken eggshell and its absorption band peak is less than 1064 cm-1. The
IP
eggshells on calcination, loose carbonate due to the decomposition of CaCO3 to CaO, which results in the decrease in the mass of the functional group attached to the CO3- ions accordingly,
CR
diminishing the intensity of CaCO3 peaks. A new peak around 3638 cm-1 corresponding to OHstretching vibration and bending hydroxyl group was also observed in the FTIR spectra of the
CE
PT
ED
M
AN
[10,16,26].
OH- groups in calcium hydroxide, Ca(OH)2
US
calcined eggshells, which corresponds to the
AC
Fig1 (a) TGA of CES (b) FT-IR spectrum of CES-Fe3O4
Fig 2 (a) shows the magnetic hysteresis of the Fe3O4 particles and magnetic composite catalysts measured at room temperature by VSM. Fe3O4 particle exhibits superparamagnetic behavior and the saturation magnetization is around 29.852 emu [7,17,19]. The coercivity, sensitivity, and retentivity were found to be 16.599G, -2.6000emu and 542.80 emu, respectively. CES-Fe3O4 particles exhibit comparatively low superparamagnetic behavior with saturation magnetization around 19.465 emu [19]. The coercivity, sensitivity, and retentivity of CES-Fe3O4 particles were found to be 14.621G, -2.6000 emu and 318.77 emu respectively. However, after the tenth cycle of transesterification with CES-Fe3O4 particles as a catalyst, it exhibits a low superparamagnetic
ACCEPTED MANUSCRIPT behavior with a magnetization around 1.2390 emu as seen in Fig 2 (a). The corresponding coercivity, sensitivity, and retentivity were found to be 18.7686G, -2.6000emu and 542.80 emu, respectively. The magnetic composite catalyst can be recovered with the aid of a magnetic field [29]. The surface area and pore size of CES and CES–Fe3O4 based heterogeneous catalysts were measured by sorption BET method. Fig.2 (b) shows the graphics isotherms of adsorptiondesorption of CES and CES-Fe3O4 based catalysts. The surface area for CES and CES-Fe3O4
T
materials was found to be 7.026 m2/g and 25.618 m2/g, respectively and the pore volume
IP
estimated for these samples was 0.0106 cc/g and 0.0956 cc/g respectively. Pore distribution was
CR
found to be high for CES- Fe3O4 based catalyst, with a pore size of 14.929 nm, which is classified as mesoporous type [14]. The isotherm graph of CES and CES- Fe3O4 shows that it
US
belongs to Type IV of the isotherm, attributing to monolayer - multilayer adsorption [30-32]. The area of the hysteresis loop formed between adsorption and desorption curve in Fig 2(b) indicates of the CES-Fe3O4 catalyst is better as compared to CES catalyst due
AN
that the catalytic behavior
to increase in the surface area owing to the formation of flakes and rough sheets as shown in the
AC
CE
PT
ED
M
TEM image Fig. 4 (b)
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
due xi
de-
M
oxiFig 2. (a)VSM image of Fe3O4 and CES-Fe3O4 (b) Curves of adsorption-desorption isotherm
ED
of CES and CES- Fe3O4(c) Size distribution of CES and CES-Fe3O4 The average size of the CES and CES-Fe3O4 samples measured by DLS was found to be 2612
PT
nm and 1629 nm respectively, as shown in Fig 2 (c). The smaller size was observed for CESFe3O4 sample, due to continuous sonication for 10 hours during the preparation of
CE
nanocomposite catalyst. The single peak in the size distribution of CES-Fe3O4 sample confirms the presence of uniform size particles whereas the two peaks for the CES sample is due to the
AC
presence of different sized particles. Fig 3 (a) shows the SEM images of the raw eggshell which has an irregular crystal structure. Even though eggshell has an irregular crystal structure, flower petals like structure are formed after calcination as shown in Fig 3 (b). The TEM image of Fe3O4 loaded calcined eggshell after sonication for 10 hours is shown in Fig 4 (b) which confirms the presence of spherical Fe3O4 nanoparticles in the structure of calcined eggshell. SEM image of Fe3O4 loaded calcined eggshell shows rough flake structure in Fig.4 (a). Due to the continuous sonication for 10 hours, the petal structures were converted to flake structure. Fig 4 (c) shows the polycrystalline diffraction patterns in the Selected Area Electron Diffraction (SAED) pattern of CES-Fe3O4 nanoparticles. The identified diffraction planes corresponds to (201), (100), (102),
ACCEPTED MANUSCRIPT (101), (001), (110) and (111) indicating that particles are in crystalline phase [3,7,16,17,19]. These results are consistent with those obtained from XRD analysis, seen in Fig 4 (e). Fig 4 (d) shows the image of catalyst CES-Fe3O4 recovery by using an external magnet. In addition, TEM image reveals that the Fe3O4 sample displays a well-defined crystal lattice stripe with a spacing of 2.82 Å and 4.92 Å corresponding to the (220) and (001) planes respectively, as shown in Fig 4 (f) [3]. The energy disperses spectroscopy results (Fig 4 (g)) confirms the presence of Iron (Fe),
T
Oxygen (O), Calcium (Ca) elements in the prepared sample and Carbon (C) which could be due
CR
IP
to the formation of CaCO3.
Fig.5 (a). shows the transformation of the catalyst into new phases [3,6,7,19]. The peaks corresponding to angles 17.3°,29.2°,47.4°,72°,84.1°, 33.6°,51.3°,54.6°,62.3°, and 64.2° is clearly
US
visible from Fig 5 (a). The sonication of CaO catalyst in Fe3O4 solution results in the conversion of CaO to Ca(OH)2 and also to CaCO3 phase loaded with Fe3O4. CaO catalyst being unstable
AN
and hygroscopic in nature tends to convert to a stable form. The formation Ca(OH)2 help to improve the yield, even though the drawback for the formation of hydroxide compound has been
M
reported [19]. Han et. al. has reported the benefit of formation of hydroxide which increases the biodiesel yield. The water molecules adsorbed initially on the metal oxide catalyst surface forms
ED
metal hydroxide (OH-) which help to accept one proton from methanol to generate methoxide (CH3O-) [19]. The high conversion of oil to methyl ester observed in the present work could be
PT
due to the formation of excess metal hydroxide Ca(OH)2 of 94%, as per the Rietveld refinement
AC
CE
data.
Fig 3. SEM image of (a) raw eggshell (b) CES after calcination at 900°C
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
Fig 4. (a) SEM image of CES-Fe3O4 (b) TEM image of CES- Fe3O4 (c) Pattern of CES-Fe3O4
M
nanoparticles (d) Recovery of catalyst CES-Fe3O4 by using an external magnet (e) XRD data of
ED
CES-Fe3O4 (f) Surface morphology and SAED (g) EDS spectra of CES- Fe3O4 The XRD pattern shows the confirmation of CES-Fe3O4 and was further studied by using the
PT
Rietveld refinement method to determine the formation of Ca(OH)2 and CaCO3. The detailed structural properties of prepared Ca(OH)2 was obtained through Rietveld refinement of the XRD
CE
pattern, as shown in Fig 5 (b). The refined XRD data confirms that the prepared sample contains 94% percentage of Ca(OH)2 phase and 6% of CaCO3 phase. Further, structural details of
AC
individual phases were also extracted from the refinement output. The presence of a higher percentage of hydroxide phase in the material results in the better conversion of oil to methyl ester.
CR
IP
T
ACCEPTED MANUSCRIPT
Fig 5. (a) XRD pattern of the CES-Fe3O4 with confirmation phases (b) Refinement data
Transesterification reaction
AN
3.2.
US
of CES-Fe3O4
The transesterification of Pongamia pinnata oil was done with CES-Fe3O4 as a catalyst. Various
M
parameters affecting the transesterification of the biodiesel includes (i) reaction temperature (ii) reaction time (iii) catalyst loading (iv) oil to methanol ratio. The parameters were optimized to
ED
obtain the maximum yield of biodiesel based on one-factor approach and the details are
PT
presented here. Temperature
CE
The effect of reaction temperature on transesterification of Pongamia pinnata oil was studied and results are shown in Fig 6 (a). FAME yield was found to be increased with increase in
AC
temperature, and achieved a maximum value at 65°C, followed by a decrease in the yield [4]. The increase in the yield with the temperature could be due to the high mobility of molecules with increase in temperature resulting in high reaction rate [33]. However as the reaction temperature goes beyond 70°C, which is the boiling temperature of methanol, methanol evaporates decreasing the biodiesel yield. Hence the reaction temperature was fixed at 65°C.
ED
M
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
PT
Fig 6. Variation of biodiesel yield with (a) reaction temperature (b) reaction time (c) loading of
Reaction time
CE
catalyst (d) oil to molar ratio.
The effect of reaction temperature on the biodiesel yield was studied and the results are shown in
AC
Fig 6 (b). The biodiesel yield was found to increase with an increase in the reaction time, with a maximum yield of 98% attained for a reaction time of 120 minutes, followed by a decrease in yield with time [6]. The reaction could have achieved equilibrium at the end of 120 minutes and afterward the shifting of the reaction occurs in the reverse direction, leading to the soap formation [34]. Hence the reaction time was fixed at 120 minutes. Catalyst loading
ACCEPTED MANUSCRIPT The catalyst loading directly affects the biodiesel yield in a transesterification reaction. The high Free Fatty Acid in the feedstock, results in the soap formation, influencing the separation process which limits the FAME yield. The variation of the yield with the catalyst loading is shown in Fig 6 (c). The biodiesel yield was found to increase with an increase in the catalyst loading, up to 2 wt% loading with a biodiesel yield of 98 %. However, a decrease in the yield was observed with further increase in the concentration of catalyst. An excess amount of catalyst adversely affects
T
the mixing of methanol, oil, and catalyst leading to phase separation [35]. Hence in the present
CR
IP
study, catalytic loading was fixed as 2 wt%. Oil to Methanol molar ratio
US
Oil to methanol molar ratio directly affects the biodiesel yield. The variation of the yield with the oil: methanol ratio is shown in Fig 6 (d). As the methanol to oil ratio increases from 1:3 to 1:12
AN
the biodiesel yield was found to increase from 56 to 98%, with further decrease in the yield [27]. Normally the excess methanol favors the shift in the equilibrium, to achieve high biodiesel yield
M
[36]. However, as the methanol concentration increases, the contents of catalyst and reactants are dissolved by methanol, which may inhibit the reaction thus reducing the biodiesel yield. The oil
ED
to methanol molar ratio was fixed at 1:12.
PT
3.3. Yield comparison
The transesterification of Pongamia pinnata oil was done by using raw animal bone, CES and
CE
CES-Fe3O4 as a catalyst, with the optimized parameters and yield were compared as shown in Fig 7 (a). The improved catalytic behavior of CES-Fe3O4 treated sample is mainly due to the
AC
increase in surface area and pore volume due to the layered structure as mentioned earlier [26,31]. The raw eggshell cannot be used as a catalyst as it does not help in the conversion of methanol to methoxide, which aids in the conversion of triglycerides to methyl ester. The economic feasibility of biodiesel production at large scale depends on the reusability and stability of the calcium-based catalyst. The reusability of the calcined chicken eggshell (900°C) was studied by carrying out the transesterification under the optimized condition, with oil to methanol ratio of 1:12, catalyst loading of 2 wt.%, a reaction temperature of 65°C and response time of 120 min. Catalysts recovered after the transesterification reaction was washed and reused and yield obtained in each cycle was compared. Fig 7 (b) shows the variation of biodiesel yield
ACCEPTED MANUSCRIPT with the cycles of transesterification. The biodiesel yield of 98% was obtained initially which was found to be consistent until the 7th cycle of the transesterification reaction, followed by a decrease in the yield. The decrease in the yield is mainly due to blockage of catalyst pores which
AN
US
CR
IP
T
further reduces the adsorption and desorption of the reactants.
M
Fig 7. (a) Biodiesel yield comparison (b) Reusability of the CES-Fe3O4
ED
Table 1. GC- MS data of raw oil; Pongamia pinnata oil
AC
CE
PT
Table 2. GC- MS data of Pongamia pinnata oil based Methyl Ester
AC
CE
PT
ED
M
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
Fig 8. GC-MS chromatogram of (a) raw Pongamia pinnata oil (b) biodiesel synthesized from Pongamiapinnata oil.
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
M
Fig 9. Adsorption and desorption on the active site of the heterogeneous catalyst -schematic
ED
The fatty acid composition of Pongamia pinnata oil was analyzed by using gas chromatographymass spectra. Table.1 and Table 2 shows the GC-MS data of Pongamia pinnata oil and Pongamia
PT
pinnata oil biodiesel respectively, in which retention time and percentage of relative abundance of fatty acid are shown. Different peaks in GC-MS chromatogram represent the presence of
CE
methyl esters and the maximum peak indicates the presence of Octadecenoic Acid (43.94%) methyl ester and a minimum of the presence of Margaric acid (0.09%). Fig 8 (b). shows that the -
C19 is maximum, while the
AC
presence of compounds with carbon atoms in the range C17
compounds with carbon atoms in the range C15-C16 is minimum. GC-MS results also establish the successful transformation of palm oil into biodiesel [15,22]. From GC-MS chromatogram Fig 8 (a), 7 major peaks of various fatty acids were visible in the case of raw Pongamia Pinnata oil whereas 13 major peaks were visible in the case of Pongamia pinnata oil based biodiesel. The increase in the number of peaks of methyl esters could be due to the conversion of raw Pongamia pinnata to methyl ester (biodiesel), shown in Fig 8 (b) [37]. The abundance data in Fig.8 (b) is higher than that in Fig.8 (a), which shows good conversion of raw oil to methyl ester (biodiesel)
ACCEPTED MANUSCRIPT [38]. Table 3. shows the comparison of present work with that of similar works on eggshells/shells based heterogeneous catalyst, reported earlier. Table 3
T
Comparison of catalytic activity with reported eggshell based heterogeneous catalysts.
IP
4. Conclusions
CR
In summary, we have demonstrated a simple route for the synthesis of magnetic recoverable CES-Fe3O4 cheap catalyst from waste eggshells. The solid base oxide catalyst was synthesized
US
by calcination of chicken eggshell at 900°C and was loaded with the nanomagnetic material (Fe3O4). Fe3O4 nanomaterials were synthesized by co-precipitation method and were loaded in
AN
calcined eggshell by sonication. The calcination followed by sonication for 10 hours results in the formation of flake-like structures with enhanced surface area. The surface area of calcined
M
chicken eggshell was found to be increased from 7.026 m2/g to 25.618m2/g with the loading of Fe3O4 nanoparticles. The transesterification of Pongamia pinnata oil was done using Fe3O4 loaded The sonication of calcined
ED
calcined chicken eggshell and the parameters were optimized.
chicken eggshell in Fe3O4 solution results in the conversion of CaO to Ca(OH)2 which aids in the
PT
enhancement of the biodiesel yield. The reusability of the catalyst was studied by performing the transesterification using the same catalyst for 10 cycles and the yield was found to be slightly
CE
decreased after the 7th cycle, which could be due to the blockage of catalyst pores, reducing adsorption and desorption of the reactants.
[1]
AC
REFERENCES:
I.M. Atadashi, M.K. Aroua, A.R. Abdul Aziz, N.M.N. Sulaiman, The effects of catalysts in biodiesel production: A review, J. Ind. Eng. Chem. 19 (2013) 14–26.
[2]
N. Mansir, S.H. Teo, I. Rabiu, Y.H. Taufiq-Yap, Effective biodiesel synthesis from waste cooking oil and biomass residue solid green catalyst, Chem. Eng. J. 347 (2018) 137–144.
[3]
W. Xie, N. Ma, Immobilized Lipase on Fe3O4 Nanoparticles as biocatalyst for biodiesel production, Energy and Fuels. 23 (2009) 1347–1353.
ACCEPTED MANUSCRIPT
[4]
Wei Z, Xu C, Li B. Application of waste eggshell as low-cost solid catalyst for biodiesel
V.C. dos Santos, K. Wilson, A.F. Lee, S. Nakagaki, Physicochemical properties of
IP
[5]
T
production. Bioresource Technol. 5 (2009) 2883-2885.
WOx/ZrO2 catalysts for palmitic acid esterification, Appl. Catal. B Environ. 162 (2015)
[6]
CR
75–84.
M.L. Savaliya, M.S. Bhakhar, B.Z. Dholakiya, Cutting cost technology for the preparation
US
of biodiesel using environmentally benign and cheaper catalyst, Catal. Letters. 146 (2016)
[7]
AN
2313–2323.
E. Mosaddegh, F.A. Hosseininasab, A. Hassankhani, Eggshell/Fe3O4 nanocomposite:
M
novel magnetic nanoparticles coated on porous ceramic eggshell waste as an efficient catalyst in the synthesis of 1,8-dioxo-octahydroxanthene, RSC Adv. 5 (2015) 106561–
Nisar J, Razaq R, Farooq M, Iqbal M, Khan RA, Sayed M, et al. Enhanced biodiesel
PT
[8]
ED
106567.
production from Jatropha oil using calcined waste animal bones as catalyst. Renew
[9]
AC
CE
Energy 9 (2017) 101:111.
V.B. Gade, A.K. Rathi, S.B. Bhalekar, J. Tucek, O. Tomanec, R.S. Varma, R. Zboril, S.N. Shelke, M.B. Gawande, Iron-Oxide-supported ultrasmall ZnO nanoparticles: Applications for transesterification, Amidation, and O-Acylation reactions, ACS Sustain. Chem. Eng. 5 (2017) 3314–3320.
[10] S.L. Lee, Y.C. Wong, Y.P. Tan, S.Y. Yew, Transesterification of palm oil to biodiesel by using waste obtuse horn shell-derived CaO catalyst, Energy Convers. Manag. 93 (2015) 282–288.
ACCEPTED MANUSCRIPT [11] S. Luz Martínez, R. Romero, J.C. López, A. Romero, V. Sánchez Mendieta, R. Natividad, Preparation and characterization of CaO nanoparticles/NaX zeolite catalysts for the transesterification of sunflower oil, Ind. Eng. Chem. Res. 50 (2011) 2665–2670. [12] Chakraborty R, Mukhopadhyay P, Kumar B. Optimal biodiesel-additive synthesis under
T
infrared excitation using pork bone supported-Sb catalyst: Engine performance and
IP
emission analyses. Energy Convers. Manag. 126 (2016) 132–141.
CR
[13] S. Semwal, A.K. Arora, R.P. Badoni, D.K. Tuli, Biodiesel production using heterogeneous catalysts, Bioresour. Technol. 102 (2011) 2151–2161.
US
[14] A.F. Lee, K. Wilson, Recent developments in heterogeneous catalysis for the sustainable
AN
production of biodiesel, Catal. Today. 242 (2015) 3–18.
[15] D. Madhu, Y.C. Sharma, Synthesis of a reusable novel catalyst (β-tricalcium phosphate)
M
for biodiesel production from a common Indian tribal feedstock, Resour. Technol. 3 (2017) 144–157.
ED
[16] Y. Liu, J. Chung, Y. Jang, S. Mao, B.M. Kim, Y. Wang, X. Guo, Magnetically recoverable nanoflake-shaped iron oxide/Pt heterogeneous catalysts and their excellent
PT
catalytic performance in the hydrogenation reaction, ACS Appl. Mater. Interfaces. 6
CE
(2014) 1887–1892.
[17] S. Tang, L. Wang, Y. Zhang, S. Li, S. Tian, B. Wang, Study on preparation of
AC
Ca/Al/Fe3O4 magnetic composite solid catalyst and its application in biodiesel transesterification, Fuel Process. Technol. 95 (2012) 84–89. [18] D.Y.C. Leung, X. Wu, M.K.H. Leung, A review on biodiesel production using catalyzed transesterification, Appl. Energy. 87 (2010) 1083–1095. [19] S. Hu, Y. Guan, Y. Wang, H. Han, Nano-magnetic catalyst KF/CaO-Fe3O4 for biodiesel production, Appl. Energy. 88 (2011) 2685–2690. [20] M. Feyzi, L. Norouzi, Preparation and kinetic study of magnetic Ca/Fe3O4@SiO2 nanocatalysts for biodiesel production, Renew. Energy. 94 (2016) 579–586.
ACCEPTED MANUSCRIPT [21] B. jin Xue, J. Luo, F. Zhang, Z. Fang, Biodiesel production from soybean and Jatropha oils by magnetic CaFe2O4-Ca2Fe2O5-based catalyst, Energy. 68 (2014) 584–591. [22] Y.C. Sharma, B. Singh, J. Korstad, Application of an efficient nonconventional heterogeneous catalyst for biodiesel synthesis from pongamia pinnata oil, Energy and Fuels. 24 (2010) 3223–3231. d
T
[23] D. Kumar, A. Ali, Transesteri fi cation of Low-Quality Triglycerides over a Zn/CaO
IP
Heterogeneous Catalyst : Kinetics and Reusability Studies, Energy and Fuels. 27 (2013)
CR
3758–3768.
[24] S.B. Chavan, R.R. Kumbhar, D. Madhu, B. Singh, Y.C. Sharma, Synthesis of biodiesel
US
from Jatropha curcas oil using waste eggshell and study of its fuel properties, RSC Adv. 5
AN
(2015) 63596–63604.
[25] M.C.G. Albuquerque, J. Santamaría-González, J.M. Mérida-Robles, R. Moreno-Tost, E.
M
Rodríguez-Castellón, A. Jiménez-López, D.C.S. Azevedo, C.L. Cavalcante, P. MairelesTorres, MgM (M = Al and Ca) oxides as basic catalysts in transesterification processes,
ED
Appl. Catal. A Gen. 347 (2008) 162–168. [26] Y.C. Sharma, B. Singh, J. Korstad, Latest developments on application of heterogenous
PT
basic catalysts for an efficient and eco friendly synthesis of biodiesel: A review, Fuel. 90
CE
(2011) 1309–1324.
[27] A.P.S. Chouhan, A.K. Sarma, Modern heterogeneous catalysts for biodiesel production: A
AC
comprehensive review, Renew. Sustain. Energy Rev. 15 (2011) 4378–4399. [28] C. Liu, P. Lv, Z. Yuan, F. Yan, W. Luo, The nanometer magnetic solid base catalyst for production of biodiesel, Renew. Energy. 35 (2010) 1531–1536. [29] S. Chen, R. Si, E. Taylor, J. Janzen, J. Chen, Synthesis of Pd/Fe3O4 hybrid nanocatalysts with controllable interface and enhanced catalytic activities for CO oxidation, J. Phys. Chem. C. 116 (2012) 12969–12976. [30] A.F. Lee, J.A. Bennett, J.C. Manayil, K. Wilson, Heterogeneous catalysis for sustainable biodiesel production via esterification and transesterification, Chem. Soc. Rev. 43 (2014)
ACCEPTED MANUSCRIPT 7887–7916.
[31] D.R. Vardon, B.R. Moser, W. Zheng, K. Witkin, R.L. Evangelista, T.J. Strathmann, K. Rajagopalan, B.K. Sharma, Complete utilization of spent coffee grounds to produce
IP
T
biodiesel, bio-oil, and biochar, ACS Sustain. Chem. Eng. 1 (2013) 1286–1294.
CR
[32] G. Corro, N. Sánchez, U. Pal, F. Bañuelos, Biodiesel production from waste frying oil using waste animal bone and solar heat, Waste Manag. 47 (2016) 105–113.
US
[33] I.B. Banković-Ilić, M.R. Miladinović, O.S. Stamenković, V.B. Veljković, Application of nano CaO–based catalysts in biodiesel synthesis, Renew. Sustain. Energy Rev. 72 (2017)
AN
746–760.
[34] Ara; Nunes, R. C. D. R.; De Moura, C. V. R.; De Moura; Dos Santos junior, J. R.,
M
Synthesis and characterization of beef tallow biodiesel, Energy and Fuels. 24 (2010)
ED
4476–4480.
[35] I.M. Atadashi, M.K. Aroua, A.A. Aziz, Biodiesel separation and purification: A review,
PT
Renew. Energy. 36 (2011) 437–443.
CE
[36] M. Balat, Potential alternatives to edible oils for biodiesel production - A review of current work, Energy Convers. Manag. 52 (2011) 1479–1492. S. Chellappan, V. Nair, V. Sajith, K. Aparna, Synthesis optimization and characterization
AC
[37]
of biochar based catalyst from saw dust for stimultaneous eterification and transesterification. Chinese J. Chem. Eng. (2018) 1082-1092. doi: [38]
Chellappan S, Nair V, Sajith V, Aparna K. Experimental validation of biochar based green bronsted acid catalysts for simultaneous esterification and transesterification in biodiesel production. Bioresour Technol Reports 2 (2018) 38–44.
ACCEPTED MANUSCRIPT Table 1. GC- MS data of raw oil; Pongamia pinnata oil Sl.No.
Retention time (min)
Fatty Acid Profile
Composition(%)
25.775
Palmitic Acid
11.33
2
30.141
Stearic Acid
6.01
3
30.452
Oleic Acid
44.45
4
31.343
Linoleic Acid
17.10
5
32.624
Linolenic Acid
2.52
6
34.145
Arachidic Acid
7
34.420
Eicosenoic Acid
8
34.729
Behenic Acid
9
37.727
Lignoceric Acid
IP CR
US
AN M ED PT CE AC
T
1
1.55 2.14
10.15 4.76
ACCEPTED MANUSCRIPT Table 2. GC- MS data of Pongamia pinnata oil based Methyl Ester Retention time (min)
Fatty Acid Profile
Composition(%)
15.867
Lauric Acid
0.21
2
21.022
Myristic Acid
0.94
3
25.736
Palmitic Acid
37.86
4
26.246
Palmitoleic Acid
0.16
5
27.911
Margaric Acid
6
30.061
Stearic Acid
7
30.446
Octadecenoic Acid
43.94
8
31.380
Linoleic Acid
11.02
9
32.689
Linolenic Acid
0.14
10
34.000
Arachidic Acid
0.45
11
34.349
Behenic Acid
0.19
12
37.721
Lignoceric Acid
0.11
13
41.169
Eicosenoic Acid
0.12
IP
CR
AN M
ED PT CE AC
T
1
US
Sl.No.
0.09 4.76
ACCEPTED MANUSCRIPT
Table 3 Comparison of catalytic activity with reported eggshells based catalysts.
Mode of operation
Eggshells with Fe3O4
12:1
2
65
2
Waste eggshells
9:1
3
65
Eggshells derived
8:1
2.5
65
Fe3O4 with alkali from eggshell
4chlorobenzalde hyde (0.14 g) and dimedone (0.28 g)
1
Waste obtuse horn shell derived catalyst.
12:1
5
Eggshells
8:1
2.5
Waste eggshells
8:1
Referenc es
Conventional
98
This work
Conventional
95
[4]
3
Conventional
99.2
[6]
0.25
Conventional
95
[7]
65
6
Conventional
86.75
[10]
65
2.5
Conventional
95
[22]
65
2.5
Conventional
AN
US
3
M
80
ED PT
CE AC
Biodiesel yield (%)
T
Reaction Time (h)
IP
Reaction conditions Reaction Methanol to oil Catalyst Temperatu ratio (mol) (wt. %) re (ºC)
CR
Waste Shells based base heterogeneous catalyst
2
90
[24]
ED
M
AN
US
CR
IP
T
ACCEPTED MANUSCRIPT
AC
CE
PT
Graphical abstract
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9