Renewable feedstocks for biobutanol production by fermentation

Accepted Manuscript Title: Renewable feedstocks for biobutanol production by fermentation Author: Alessandra Procentese Francesca Raganati Giuseppe Olivieri Maria Elena Russo Marco De La Feld Antonio Marzocchella PII: DOI: Reference:

S1871-6784(16)32517-1 http://dx.doi.org/doi:10.1016/j.nbt.2016.10.010 NBT 931

To appear in: Received date: Revised date: Accepted date:

13-4-2016 18-10-2016 28-10-2016

Please cite this article as: Procentese, Alessandra, Raganati, Francesca, Olivieri, Giuseppe, Russo, Maria Elena, De La Feld, Marco, Marzocchella, Antonio, Renewable feedstocks for biobutanol production by fermentation.New Biotechnology http://dx.doi.org/10.1016/j.nbt.2016.10.010 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.

Renewable Feedstocks for Biobutanol Production by Fermentation Alessandra Procentese2,*, Francesca Raganati1, Giuseppe Olivieri1, Maria Elena Russo2, Marco De La Feld3, Antonio Marzocchella1 Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale – Università degli Studi di Napoli Federico II, P.le V. Tecchio 80, 80125 Naples, Italy 1

Istituto di Ricerche sulla Combustione – Consiglio Nazionale delle Ricerche,P.le V. Tecchio 80, 80125 Naples, Italy 2

3

ENCO S.r.l. Engineering & Consulting – Via Michelangelo Schipa 115, 80122 Naples, Italy

*Corresponding author Dr Alessandra Procentese Ph: +39 0817682541 Fax: +39 0815936936. E-mail address: [email protected]

Highlights    

A survey of available European feedstock for bio-butanol production was reported 43% of the European demand for biofuel may be replaced by agriculture residues Encouraging results rise from analysis of use of Mischantus crops in Campania 50% of the Campania demand for biofuel may be replaced by dedicated Mischantus crop

Abstract This paper reports a study of potential feedstock for butanol production via the biotechnological route. Several waste(water) streams rich in sugars and lignocellulosic biomass were studied: cheese-whey, leftovers of high sugar-content beverages, food lost or wasted, agriculture residues. The maximum butanol production rate from each type of feedstock was assessed according to the parameters indicated in the literature: feedstock availability rate, feedstock average composition and butanol yield. In Europe the potential biotechnological production of butanol from the feedstock studied was assessed to be about 39 Mt yr-1, which would be enough to meet the current European demand of biofuels. The potential butanol production at local level was also assessed taking into account the concentration of feedstock suppliers in the Campania region. Keywords Feedstock, butanol, lignocellulosic biomass, waste, survey, fermentation

Introduction Environmental awareness of the effects of the exploitation of fossil-based resources and the planned global actions to decrease greenhouse gas emissions have led to an increasing interest in renewable resources for production of chemicals, materials and energy vectors, including biofuels. The huge demand for liquid fuels (diesel and gasoline) in the Europe Union (EU) (Table 1) has experienced a modest inflection during the years of economic crisis, but a light trend inversion has been recorded more recently. However, fuel demand is still high and a huge amount of renewable resources are required to fulfil the European Directive 2009/28/CE: “…. a mandatory target of a 20 % share of energy from renewable sources in overall Community energy consumption by 2020 and a mandatory 10 % minimum target to be achieved by all Member States for the share of biofuels in transport petrol and diesel consumption by 2020, to be introduced in a cost-effective way”. Taking into account the energy content of diesel and gasoline at about 45 MJ kg-1 and 47 MJ kg-1, respectively, fuel demand in the European Union in 2014 averages about 1.4 * 1013 MJ year-1. Assuming that the need for renewable transportation fuels in the EU will account for 20% of current total demand, 2.7*1012 MJ year-1 of biofuels will be required to fulfil the EU commitment.

Table 1.

Butanol is a 4-carbon alcohol that may be used as chemical building block and as a biofuel (energy content 36.6 MJ kg-1). Compared to bio-ethanol – a well known biofuel - butanol is characterized by high energy content and low volatility, and is less corrosive [2]. A potential route to produce n-butanol is by Clostridial fermentation, commonly known as ABE (acetone–butanol– ethanol) fermentation [3]. However, a critical issue of this route is the cost of the substrate, which affects about 60% of the overall production cost of butanol[4]. Therefore, the focus for the industrial success of the ABE includes

scouting for renewable feedstock available at high mass rate,

characterized by constant availability over the year and low cost. To the authors’ knowledge, only a

few studies reported in the literature have considered the amount of feedstock available for biofuel production: municipal solid waste by Noor (2014) [5] and food waste by Kiran et al. (2014) [6]. This paper reports a survey of several European feedstocks potentially available for butanol production by the biotechnological route. Assessment of the butanol production rate is carried out taking into account both the known sugar composition of the feedstock and the butanol yields reported in the literature. Potential European butanol productivity is compared with European fuel demand. A case study is reported regarding butanol production on a regional scale to consider the logistical issues related to the harvesting of the feedstock.

FEEDSTOCK ANALYSIS AND PROCEDURE Feedstock analysis Five potential feedstocks for butanol production by biotechnological route were considered: cheese-whey, high sugar content beverage, lignocellulosic biomass, agricultural residues and food wastes. The composition and the market of these feedstocks are reported below.

Cheese-whey The dairy industries are pressured by the production of a huge mass stream rate of wastewater. As a rule of thumb, the processing of 1 kg of milk produces 0.2 kg of cheese and 0.8 kg of wastewater, known as cheese-whey. The organic fraction of the cheese-whey is remarkably high: the Biochemical Oxygen Demand (BOD) and the Chemical Oxygen Demand (COD) are about 35 g L-1 and 70 g L-1, respectively [7]. In particular, the COD is larger than the limit set by the European Commission of 250-500 mg L-1 for discharge into sewerage systems (75/440/EEC). Therefore, the cheese-whey must be treated in order to reduce the COD and its disposal is quite expensive. Molella and co-workers [8] carried out an analysis of cheese-whey regarding its impact as a pollutant. They reported that a small dairy produces about 20 m3 day-1 of wastewater, a pollution comparable to a community of about 10,000 people.

The cheese-whey may be used as feedstock for industrial processes:(i) as a dietary supplement for farm animals, and (ii) as a source of lactose to be used in the confectionery industry. The supply of confectionery industries is very interesting from the economic point of view, but the market is rather small and the investment for production is quite high. Therefore, an alternative fate of the cheese-whey must be sought to reduce the disposal issues. The option as feedstock for the ABE fermentation to produce butanol has already been verified [8]. The main advantages of cheese-whey as an ABE fermentation feedstock are: continuous production over the year at an almost constant rate, production in small regional areas and a negative cost of supply (the remediation cost becomes an income for the ABE fermentation process). These features positively affect the economic aspect of the butanol production process. The critical issues related to the use of cheese-whey as an ABE fermentation feedstock are storage and transport. Indeed, the high sugar content of cheese-whey supports spontaneous fermentation. Therefore, the butanol production plants must be located as close as possible to dairies. Cheese-whey produced in the European Union is about 40 Mt yr-1 [8].

High sugar content beverages High sugar content beverages (HSCBs), such as fruit juices, syrups, soft drinks, and sport drinks, may be a potential carbon source for ABE fermentation. Dwidar et al. (2012) [10] and Raganati et al. (2015) [11] showed that HSCBs are good candidates butanol production. They contain a wide spectrum of sugar (e.g. sucrose and fructose) at concentrations ranging from a few grams per litre to hundreds of grams per litre. The European market size for HSBCs is about 70 Mt yr-1 and about 0.1% of the production - e.g., beverages outside commercial targets, process wastewaters, seizures of badly repaired or illegal goods, and stocks after their expiration date - may request remediation. The main advantages of HSCBs as ABE fermentation feedstock are their continuous availability over the year at an almost constant rate and a negative cost of supply. The critical issue

related to the use of HSCBs is the transport cost. Other than the beverages outside the commercial targets and of the process wastewaters, the HSCBs to be treated may be dispersed around the country. Of course, the beverages out of the commercial targets and the process wastewaters are available at the HSCB production enterprises.

Dedicated lignocellulosic biomass Lignocellulosic biomass is one of the most abundant natural resources. Its main advantages as a fermentation feedstock are due to the “carbon quasi-neutral” feature of the produced biofuels: the combustion of biofuels releases about as much CO2 as that fixed during the biomass growth. However, the CO2 emitted by the biofuel production process (biomass harvesting, pre-treatment processes, fermentation processes, biofuel recovery and concentration) makes the carbon balance positive [12]. The main issues to take into account in the selection of lignocellulosic biomass as feedstock for butanol production are the spectrum of cultivar available in each country, the growth time of the cultivars, the demand for each cultivar for other purposes, and harvesting, transport and pre-treatment costs. The lignocellulosic species present in Europe and receiving attention for biofuel production are the short rotation crops. These can be classified into two different specialized systems: short rotation forestry (SRF) and short rotation coppice (SRC). Both crops consist of high-yield varieties and tolerate several rotations. The differences between the two are the period of rotation - from 8 to 20 years for SRF and from 2 to 4 years for SRC - and the species. The species included in SRF in central Europe and Scandinavian countries are aspen, alder and birch; those in SRC are willow and poplar. Willow is mainly produced in Sweden, Finland, Denmark, the Netherlands, the UK and Ireland. Poplar and robinia are cultivated in warmer climates such as the Mediterranean area (Italy, France and Spain) [13]. The EU Forest Action Plan promotes the use of forest materials as energy source provided that the forest should not decline. Many European countries have adopted specific legal measures to

support these objectives: e.g. law 43/2003 of woodlands in Spain set out principles and goals for forest management. Figure 1 shows the total roundwood production in the EU-28 between 2005 and 2012 [14]. Roundwood production has been almost constant at about 315 Mt yr-1, of which Germany, France, Finland, and Sweden provide approximately half. The extension of the forests and other woodland in the EU is about 180 million hectares, or about 42 % of the area of the EU[14]. Woodland covers a slightly greater fraction of the land than that used for agriculture (about 40 %). Sweden reports the largest wooded area (31.2 million hectares), followed by Spain (27.7 million hectares), Finland (23.3 million hectares), France (17.6 million hectares), Germany (11.1 million hectares) and Italy (10.9 million hectares). Of the total area of the EU covered by woodland, Sweden accounted for 17.3 %, Spain for 15.4 % and Finland for 12.9 % [14].

Figure 1. Gomez et al. [15] reported that about 21% of total roundwood production is wood-fuel dedicated to produce energy. Indeed, the largest fraction is used by the forest based industries to produce wood-related products (sawn wood, wood panels, pulp and paper). Extending the fraction reported by Gomez et al. [15] to the overall forest and woodland in EU, about 36 million hectares may be committed to grow lignocellulosic biomass for fuel production. Biobutanol may be successfully produced from dedicated lignocellulosic biomass by fermentation [16]. Aqu et al. [16] reported efficient ABE fermentation of Miscanthus giganteus after dilute acid pretreatment and detoxification.

Agricultural residues Agricultural residue/wastes are produced during lignocellulosic harvesting processes and from crops. Lignocellulosic harvesting processes include arboreal residues, e.g. pruning of olive groves, vineyards, and orchards. Crop-derived wastes include residues of grains, corns, flowers, grass,

and straws. The main relevant features of this typology of residues are seasonal production and high humidity. Seasonal production makes the availability of the material variable over the year; the average availability rate of agricultural residues is approximately 150 Mt yr-1 [17]. The mass rate of agricultural residues is lower than that for the lignocellulosic dedicated biomass. However, agricultural residues are characterized by low lignin content, so that the cost of the agricultural residue pre-treatment is expected to be lower than that required for the lignocellulosic dedicated biomass. Tests carried out with agricultural residue/wastes to produce fermentable sugars and butanol [18][19] have shown that this kind of biomass is well suited to butanol fermentation.

Food loss and food waste Annual global food waste is estimated to be about 1.3 billion tons, about one third of the total food production for human consumption [20]. The waste problem along ’the food chain’ was presented several years ago to the European Parliament in October 2010 with the “Declaration Against Food Waste”. The declaration of the Parliament and the European Commission was to promote strategies and resolutions aimed at reducing food waste by at least 50% by 2025. The report “Strategies for a More Efficient Food Chain in the EU” was drawn up and approved in 2012. Recently, the Swedish Institute for Food and Biotechnology proposed a distinction between food loss and food waste. Food loss “takes place during agricultural production, post-harvesting, and processing stages in the food supply chain” and is due to climatic and environmental factors and accidental causes that can be traced back to the low development of agricultural technology and infrastructures used in some geographic areas. Food waste occurs “at the end of the food chain (distribution, sale and final consumption): “the food waste comes from behavioural factors and intentional choices, based on which perfectly edible food is discarded and thrown away”. Table 2 reports food loss and waste pro capita in European Union and no European Union countries. The highest value is reported for United Kingdom and United States (about 110 kg yr-1 per capita), and the lowest for Sweden (72 kg yr-1 per capita).

Table 2. Figure 2 reports the main sources of the loss/wasted food in Europe altogether about 89 Mt year-1 [21]. The household fraction (42%) is the main contributor to food waste; the fraction of food waste from the food processing (39%) and the catering and restaurant services (14%) are also remarkable. The lost/wasted foods are a huge resource of carbohydrate–based biomass that may be potentially used as feedstock in ABE fermentation [22]. Moreover, this resource is safe, available at quite a high annual rate, and at a negative cost of supply (the disposal/remediation cost becomes an income for the ABE fermentation process).

Figure 2 The reported carbon sources are typically distributed around the countries. Therefore, their processing as feedstock for the butanol production requires harvesting and transport to the biofuel production plants. A possible exception to this drawback is made by cheese-whey, the HSCBs and the food loss/wastes. Indeed, some scenarios of concentration of these resources may be found in Europe (e.g. regional areas with industry clusters focused on the same products). This issue is very relevant for the energy/economic assessment of butanol production sustainability and is outide the present investigation. Huang et al. [23] reported butanol production from food waste; 18.9 g/L ABE and high ABE productivity (0.46 g/L/h) and yield (0.38 g/g) were reported when 81 g/L of food waste (containing equivalent glucose of 60.1 g/L) was used as substrate.

Expected butanol productivity Potential butanol productivity from renewable resources has been assessed taking into account the annual availability (Wresource), the sugar composition of the resource with respect to fermentable sugars, and the butanol yield for each fermentable sugar (Ybutanol/sugar,i). The maximum expected

butanol production rate (WButanol) from each feedstock has been assessed according to the following relation: 𝑊𝐵𝑢𝑡𝑎𝑛𝑜𝑙 = 𝑊𝑓𝑒𝑒𝑑𝑠𝑡𝑜𝑐𝑘 × [∑𝐹𝑒𝑟𝑚 𝑠𝑢𝑔𝑎𝑟𝑠(𝜔𝑠𝑢𝑔𝑎𝑟,𝑖 × 𝑌𝑏𝑢𝑡𝑎𝑛𝑜𝑙⁄𝑠𝑢𝑔𝑎𝑟,𝑖 )]

(1)

where ωsugar,i is the mass fraction of the sugar “i" in the resource. The summation refers to all the fermentable sugars of the selected resource. The chief assumptions for the assessment of the maximum butanol production adopting the investigated feedstock are the following. Lignocellulosic feedstocks 

The lignocellulosic biomass is made up of cellulose, hemicellulose, and inert. The mass fraction of cellulose and hemicellulose reported by Kumar et al. (2009) [24] was adopted.



Lignocellulosic treatment converts all the cellulose into glucose.



Lignocellulosic treatment converts all the hemicellulose into glucose, mannose, arabinose and xylose and the mass ratio among the listed simple sugars has been set at 5:1:2:4.



Food based feedstock: a reference composition has been set for glucose, mannose, arabinose and xylose at 1:1:1:1.

Non-lignocellulosic feedstocks  The main sugar component was assumed to be the carbon source (e.g. lactose for cheese-whey).  The butanol yield has been set according to data reported in the literature. It has been set at: (i) 0.26 gbutanol/gsugar for lactose [25]; (ii) 0.24, 0.15, 0.16, and 0.19 gbutanol/gsugar for glucose, arabinose, mannose, and xylose, respectively [26]; (iii) 0.16 gbutanol/gsugar for HSCBs, an average value assessed from data reported by Raganati et al. (2015) [27]; (iv) 0.20 gbutanol/gsugar for hemicellulose, as an average value taking into account the composition and the butanol yield of each component; and (v) 0.20 gbutanol/gsugar for food waste, as an average value taking into account glucose, mannose, arabinose, xylose, lactose, sucrose and fructose yields.  The European production rate of cheese-whey has been set at 40 Mt yr-1.

 The European HSCB market is of the order of 70 Mt yr-1 and 0.1% has been taken into account as the stream to be disposed of or remediated (about 0.07 Mt yr-1). 

21% of the total amount of European lignocellulosic biomass production rate (63 Mt

yr-1) has been taken into account as available lignocellulosic biomass rate.  The stream mass rates of agricultural residue and of food loss/waste have been assessed assuming that the whole European amount of agricultural residues and loss/waste food is used for the butanol production.

Case study The butanol production analysis has been customized with reference to a regional scenario. The Campania in southern Italy has been taken as a regional scenario. This area is characterized by high production mass rate of both cheese-whey and agricultural residues (e.g. grapevine residues). Moreover, the Mediterranean temperate climate supports intensive production of dedicated lignocellulosic biomass. Hence. three feedstocks have been taken into account: cheese-whey, agricultural residues, and dedicated lignocellulosic biomass. The availability mass rate of cheese-whey and agricultural products has been assumed from the literature ([28] [29]). Agricultural residues have been assumed to be 50% of the regional agriculture products. As regards the dedicated lignocellulosic biomass, the Miscanthus species has been taken into consideration. Miscanto sinensis is a grass with narrow leaves, growing well on poor lands up to 3 m in height. It is a perennial plant and therefore does not need to be replanted every year. It grows in well-drained soil and with full sun. Currently Miscanthus crops are carried out by ENEA in Sicily [30]. In Campania region the Total Agriculture Surface value (SAT) is about 722.424 ha, the Utilizable Agriculture Surface value (SAU) is about 549.270 ha [31]. The available Agriculture Surface to produce Miscanthus crops has been calculated as the difference between SAT and SAU

values: 173.154 ha. Assuming the annual areal productivity of Miscanthus reported by [32] 20.000 kg ha-1 yr-1, the Miscanthus potential availability in Campania region is about 3460 t year-1. The regional fuel demand has been calculated assuming 3,420,000 vehicles [33] and a fuel consumption of 40 L week-1. The annual demand of fuel is about 6 Mt yr-1 and the 2020 biofuel demand is about 1.2 Mt yr-1 corresponding to 5.6*1010 MJ year-1.

Results European assessment Table 3 reports the assessment of the European maximum butanol year productivity carried out with reference to the investigated available feedstock.

Table 3. The total expected butanol productivity has been assessed to be about 39 Mt yr-1, which is about 1.4 * 1012 MJ year-1. The expected butanol energy production is about 52% of the 20% of the renewable energy demand of the EU, 2.7 * 1012 MJ year-1. Figure 3 describes the potential capacity of the investigated feedstock to meet the European demand for biofuels. In particular, the ratio between the maximum expected butanol production from each feedstock and European demand for biofuels is reported. The analysis of data in Figure 3 suggests that the residue/waste streams from the investigated food industries are sufficient to supply about 5% of the 2020 biofuel European demand. The proportion may increase up to about 65% if the lignocellulosic biomass and agricultural residues are converted into butanol. Moreover, the biofuel production should be integrated with the ethanol produced during the ABE fermentation, about 10% of the mass butanol production or energy-butanol production.

Figure 3

A number of considerations arise in regard to the reported scenario. The first consideration relates to the assessed butanol production annual rate. This is an overestimation of the butanol production rate because the sugar conversion may not be complete, a fraction of butanol may be lost during the recovery and concentration process, and other fates of the feedstock may compete with butanol fermentation supply (e.g. lactose recovery from cheese-whey). The second consideration relates to the use of waste streams from industries: the current European rules (European directive COM (2012) 595) allow counting the supplemented fraction of biofuel twice. According to current European rules, the butanol produced by using the residue/waste streams from the investigated food industries is broadly sufficient to fulfil the 2020 European target regarding biofuel, i.e. 20% of biofuel. Although the results of the reported assessment are promising for the industrial success of butanol production via the biotechnological route, the development of

sustainable industrial

processes must take several issues into account. In particular, a sound assessment of sustainable development must include the impact of the national distribution on feedstock, the energy/material required for feedstock processing, and the external resources to be used for butanol production. Indeed, a sustainable analysis must take into account the following. 1.

The energy balance of the overall process. The energy associated with the butanol produced must be larger than that fed into the process. The energy saved for the disposal of the investigated streams should be included;

2.

The material balance on CO2 equivalent. The CO2 released directly and/or indirectly during the overall process must be smaller than that released by the conventional process to produce the biofuel. The CO2 released during the disposal of the investigated streams should be included.

3.

The cost analysis. The production cost must be competitive with the current cost of European biofuel supply (about 600 kg/t). The cost saved for the disposal of the investigated streams should be included.

It is worth noting that the reported analysis may be extended to the production of different bioproducts. Indeed, all suggested biomasses could be used to feed different fermentation processes (ethanol, chemical building blocks, etc). Therefore, the objective function for the exploitation of the investigated biomasses should take into account the portfolio of potential bioproducts, the market of these bioproducts, and the environmental and socio-economic impacts of the biotechnological routes to produce the bioproducts with respect to well consolidated process.

Local assessment-case study Table 4 reports the assessment of the maximum butanol year productivity in the Campania area. The contribution to current Campania biofuel demand of the expected maximum butanol production from the investigated feedstocks is also reported.

Table 4. The total expected butanol productivity has been assessed at about 0.9 Mt yr-1, which is about 3*1010 MJ year-1. The expected butanol production is about 58% of the expected biofuels demand of the region Campania, estimated as 20% of the current fuel demand of the region. The very promising scenario in Campania may further be advantageous if the national distribution of the industries which voted to produce the investigated feedstocks are taken into account. Indeed, the food processing industries are mainly localised in specialised area of the Campania - e.g. the dairies in Caserta and Salerno – and they may deliver the waste (water) streams at the butanol production plant without excessive impact on the process sustainability.

Conclusion Potential butanol production via the biotechnological route in Europe has been assessed assuming waste(water) streams rich in sugars and lignocellulosic biomass (cheese-whey, leftover of high sugar content beverages, food loss/waste, agricultural residues) as feedstocks. The processing of

waste(water) streams to produce butanol is sufficient to meet the current European biofuel demand (about 60 Mt yr-1). A detailed assessment of the sustainability of processes dedicated to produce butanol from the investigated feedstocks requires further analysis that takes into account the balance of energy, CO2 and costs. The success of butanol production processes may be strongly affected by local scenario regarding the availability of feedstock.

Acknowledgment The authors thank the Ministero dello Sviluppo Economico for the financial support to the project EuroTransBio ETB-2012-16 OPTISOLV (Development, optimization and scale-up of biological solvent production).

References [1] Fuels Europe Data, http:// www.fuelseurope.eu/; 2016 [accessed 25.02.2016]. [2] Jin C, Yao M, Liu H, Lee C, Ji J. Progress in the production and application of n-butanol as a biofuel. Renew Sust Energ Rev 2011; 15(8): 4080-4106. [3] Zheng YT, Tsuyoshi Y, Ming G, Qunhui W, Kenji S. Continuous butanol fermentation from xylose with high cell density by cell recycling system. Bioresour Technol 2013; 129: 360–365. [4] Maiti S, Sarma S J, Brar S K, Bihan Y L, Drogui P, Buelna G, Verma M, Soccol C R. Novel spectrophotometric method for detection and estimation of butanol in acetone-butanol-ethanol fermenter. Talanta 2015; 141:116-121. [5] Noor Z. An overview for energy recovery from municipal solid wastes (MSW) in malaysia scenario. Renew Sustain Energy Rev. 2013; 20:378–84. [6] Kiran E U, Trzcinski AP, Liu Y. Bioconversion of food waste to energy: A review. Fuel 2014; 134: 389-399. [7] Becerra M, Cerdan M E, Gonzalez-Siso M I. Biobutanol from cheese whey. Microbial cell factories 2015;14-27. [8] Mollea C, Marmo L, Bosco F. Valorization of cheese whey, a by-product from the dairy industry. In: Muzzalupo I, editor. Agricultural and Biological Science, E-Publishing Inc; 2013. [9] Procentese A, Raganati F, Olivieri G, Russo M, Salatino P, Marzocchella A. Continuous lactose fermentation by Clostridium acetobutylicum – Assessment of solventogenic kinetics. Bioresour Technol 2015; 18:330–337. [10] Dwidar M, Lee S, Mitchell RJ. The production of biofuels from carbonated beverages. Appl Ener 2012; 100:47–51. [11] Raganati F, Procentese A, Montagnaro F, Olivieri G, Marzocchella A. Butanol Production from Leftover Beverages and Sport Drinks. BioEner Research 2015; 8: 369–379. [12] Farrell AE, Plevin RJ, Tumer BT, Jones AD, O’Hare M, Kammen DM. Ethanol can contribute to Energy and Environmental Goals. Science 2009; 311(5760): 506-8. [13] Bergante S, Facciotto G, Miniotta G. Identification of the main site factors and management intensity affecting the establishment of Short-Rotation-Coppices (SRC) in Northern Italy through stepwise regression analysis. Cen European J Biology 2010; 5(4): 522-530. [14] Eurostat, http://www.eurostat.it/; 2014 [accessed 10.9.2014]. [15] Gomez N, Belda M. Biofuel policies for dynamic markets. Demand for lignocellulosic biomass in Europe 2010 Elobio Intelligent Energy Europe report

[16] Aqu CV, Ujor V, Gopalan V, Ezeji TC. Use of Cupriavidus basilensis-aided bioabatement to enhance fermentation of acid-pretreated biomass hydrolysates by Clostridium beijerinckii. J Ind Microbiol Biotechnol 2016; 43(9): 1215-26. [17] European Biofuels Technology Platform, http://www.biofuelstp.eu/agri-residues/; 2014 [accessed 10.11.2014]. [18] Procentese A, Johnson E, Orr V, Garruto A , Wood J, Marzocchella A, Rehmann L. Deep Eutectic Solvent Pretreatment and Saccharification of Corncob. Bioresour Technol 2015; 192:31-36. [19] Noomtima P, Cheirsilp B. Production of Butanol from Palm Empty Fruit Bunches Hydrolyzate by Clostridium acetobutylicum. Energy Procedia 2011; 9: 140 – 146. [20] FAO, http://www.fao.org/; 2014 [accessed 19.11.2014]. [21] Buchner B, Fischler C, Reily J, Riccardi G, Ricordi C, Veronesi U. Food waste: causes, impacts and proposals. Barilla Center for Food & Nutrition, Report 2012. [22] Sarchami T, Rehmann L. Optimizing Acid Hydrolysis of Jerusalem Artichoke-Derived Inulin for Fermentative Butanol Production. BioEner Resour 2015; 8(3): 1148-1157. [23] Huang H, Singh V, Qureshi N. Butanol production from food waste: a novel process for producing sustainable energy and reducing environmental pollution. Biotechnol for Biofuels 2015: 8;147 [24] Kumar P, Barrett DM, Delwiche MJ, Stroeve P. Methods for pretreatment of lignocellulosic biomass for efficient hydrolysis and biofuel production. Ind Eng Chem Res 2009;48(8): 3713– 3729. [25] Napoli F, Olivieri G, Russo ME, Marzocchella A, Salatino P. Continuous lactose fermentation by Clostridium acetobutylicum - Assessment of acidogenesis kinetics. Bioresour Technol 2011;102(2): 1608–1614. [26] Raganati F, Procentese A, Olivieri G, Russo ME, Salatino P, Marzocchella A. Biobutanol Production from Hexose and Pentose Sugars. Chem Eng Trans 2014; 38: 193–198. [27] Raganati F, Procentese A, Montagnaro F, Olivieri G, Marzocchella A. Butanol Production from Leftover Beverages and Sport Drinks. BioEnergy Research 2015; 8: 369–379. [28] ISTAT, CGA 2000 http://www.ISTAT.it/; 2015 [accessed 13.09.2015]. [29] CLAL, http//www.clal.it/; 2014 [accessed 10.02.2014]. [30] Filippi N, Lucci S. Qualità e vulnerabilità dei suoli in Colture a scopo energetico e ambiente. Sostenibilità, diversità e conservazione del territorio. Atti Convegno APAT 2007. [31] Regione Campania Assessorato Agricoltura, http://www.agricoltura.regione.campania.it/; 2015 [accessed 10.10.2015].

[32] Energie pflanzen, http://www.energiepflanzen.com/; 2015 [accessed 10.10.2015] [33] Automobile Club D’Italia - ACI 2013, http://www.aci.it/; 2015 [accessed 5.10.2015].

Figure Legends Figure 1. Annual European roundwood production [13] Figure 2. Food loss and waste distribution [18] Figure 3. Contribution to the current European biofuel demand (assessed as 20% of the fuel demand) of the expected maximum butanol production from the investigated feedstocks

350

300

Mt yr-1

250

200

150

100

50

0 2005

2006

2007

2008

2009

Year

Figure 1.

2010

2011

2012

% Total Food waste and loss

50

40

30

20

10

0

ale a e/C

W

vic

od

g

g in

in

r te

les

ho

r Se

r tu

nu

Ma

Fo

Figure 2.

c fa

ld ho

e us Ho

Figure 3.

Table 1. European liquid fuel demand (Mt yr-1) [1] Fuel 2011 2012 2013 2014 Diesel 200 196 198 200 Gasoline 98 95 80 80

Table 2. Food loss and waste: from Buchner et al. (2012) [18] Nation United Kingdom United States Italy Germany France Sweden

Food loss and waste (kg per capita per year) 110 109 108 82 99 72

Table 3. Maximum expected butanol productivity in Europe by converting the investigated feedstocks via the biotechnological route.

Cheese-whey

Feedstock available for biobutanol production (Mt yr-1)(a) 40

HSCB

0.07

Feedstock

Lignocellulosic 63 biomass Agriculture 150 residues Food 89 loss/waste (a) As delivered at the production site

SUGAR COMPOSITION (%wt)(b) 4% lactose 50% (glucose, fructose, saccarose, ..) (*) 45% cellulose 30% hemicellulose 30% cellulose 50% hemicellulose 50% (glucose, fructose, saccarose, ..) (c)

Maximum expected butanol productivity (Mt yr-1) 0.416 0.006 10 26 3

(b) The composition refers to the total weight (c) The composition refers to the dry weight and the 30% of the dry matter has been assumed

Table 4. Maximum expected butanol productivity in Campania (Italy) by converting the investigated feedstocks via the biotechnological route.

Feedstock

Availability mass flow rate (Mt yr-1)

Cheese-whey

0.5

Agricultural residues

2

Mischantus

3

SUGAR COMPOSITION (%wt)

Maximum expected butanol productivity (Mt yr-1)

Contribution to the current Campania biofuel demand

4% lactose

0.005

0.43%

0.3

26.12%

0.6

50.49%

30% cellulose 50% hemicellulose 45% cellulose 30% hemicellulose