Fluidized bed combustion of Huadian oil shale

Fluidized bed combustion of Huadian oil shale

09 Combustion (burners, combustion systems) diffraction; (3) finding the temperature history and half bandwidth relationship; (4) screening ...

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09 Combustion

(burners, combustion


diffraction; (3) finding the temperature history and half bandwidth relationship; (4) screening <3 mm particles from solid sample in the combustion zone; (5) determining the half bandwidth for carboncontaining sample by X-ray diffraction; (6) finding its temperature history from the relationship; (7) similarly finding the half bandwidth and temperature history for another sample powder with different inlet conditions; and (8) comparing their temperature histories. The higher the temperature, the higher the combustibility.

02/00568 Combination of pyrolysis equipment with power plant coal combustion Schulz, W., Hauk, R. Stoffliche Therm. Verwert. Abfaellen Ind. Hochtemperaturprozessen, DVV-Kolloq.. llth, 1998, 231-246. (In German) A plant for the thermal utilization of organic wastes is presented, and the pyrolysis technology was selected because it was very flexible on this purpose and also could be combined with power plants. The plant had the capacity of 100000 tons annually, and waste smaller 200 mm edge size was pyrolysed at about 500”. The pyrolytic gas was purified and utilized for power plant fuelling, while the solid residues were separated into coke, iron-metals, non-iron-metals, and inert materials.

02lOO569 Combustion aid for coal Hou, G. ef al. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,232,076 (Cl. ClOL9/10), 20 Ott 1999, Appl. 98,107,186, 1 I Apr 1998. 4. (In Chinese) The combustion aid comprises KMn04 0.5-99.5, NaCl 0.1-90, Fez03 0.1-30, and REC13 O-l%. The combustion aid is mixed with water to form a suspension before mixing with coal, and the heat efficiency of coal is improved and carbon content in cinders and fume is reduced.

02/00570 Comparative pyrolysis and combustion kinetics of oil shales Kok, M.V., Pamir, M.R. J. Anal. Appl. Pyrolysis, 2000, 55, (2), 185194. In this research, thermal characteristics and kinetic parameters of eight Turkish oil shale samples were determined by thermogravimetry (TG/ DTG) at non-isothermal heating conditions both for pyrolysis and combustion processes. A general computer program was developed and the methods are compared with regard to their accuracy and the ease of interpretation of the kinetics of thermal decomposition. Activation energies of the samples were determined by five different methods and the results are discussed.

02/00571 Development of multipurpose coal conversion technology Kaijo, T. et al. Sekiran Ri~o Gijutsu Kaigi Koenshu, 1999, 9, 249-258. (In Japanese) A 7 t/d process develop unit (PDU) was used to study a combined coal pyrolysis-gasification process experimentally. In the process, a fraction of the char formed in the rapid pyrolysis process is recycled and gasified in the presence of low-pressure 02. The effects of operating temperature and coal types on product yield and product composition were discussed. Plans for future pilot plant study are described.

02lOO572 Development of pressurized internally circulating fluidized bed gasification technology Hosoda, S . ei al. Sekitun Riyo Gijutsu Kaigi Koenshu, 1999, 9, 45-55. (In Japanese) A review, with no references, of the title technology, in terms of basic structure and function, operational performance, and futdre development schedule.

02100573 Direct combustion of oil shale using a circulating fluidized-bed combustor Hamdan, M.A.I., El-Azzam, S.M. Dirasat; Eng. Sci., 1999, 26, (2), 174181. A stainless steel circulating fluidized-bed combustor was designed, constructed, and tested for burning oil shale particles. During experimental work, Chromel-Alumel (K-type) thermocouples were used to measure the temperature distribution along the bed. Further, and in order to control the emitted gases, a gas chromatography technique was used to analyse the exhaust products from the bed. Finally, the remaining ash in the bed was analysed for the unburned carbon and thus the combustion efficiency of the bed was determined. It was found that there is a high feasibility for Jordanian oil shale to be directly and continuously burned using a circulating fluidized-bed combustor. The average maximum bed temperature obtained was 950”, while the combustion efficiency has a value ranging between 90% and 97%. 58

Fuel and Energy


January 2002

02/00574 Dynamics of combustion of solid fuel particles in a fluidized bed under pressure Maistrenko, A.Y., Topal, A.I. Ekorekhnol. Resursosberezhenie, 2000, 3, 12-16. (In Russian) The results of an experimental study on the effect of pressure (0.1-1.6 MPa) on combustion behaviour of coal particles in a fludized bed reactor are presented. The dynamics of the formation of combustion products and temperature variation are obtained. The effective combustion times and specific reaction rates as a function of the conversion degree for the main types of Ukrainian coals used in power plants are calculated. The empirical correlation of the data was also included. 02/00575 Effect of catalysts on the pyrolysis of Turkish Zonguldak bituminous coal Oeztas, N.A., Yueruem, Y. Energy Fuels, 2000, 14, (4), 820-827. Raw coal, HCl-treated coal, and HCl-HF treated coal samples ZnClz, NiCIz, CoCIz, CuClz and Fe20s.S04 as catalysts were pyrolysed under various temperature and time conditions in an inert atmosphere. The conversion of organic matter was calculated. The change in the aliphatic hydrogen and the degree of aromatic condensation by FTIR technique have been examined a function of temperature, time, and catalyst type. The volumetric swelling ratio of the chars obtained in different experimental conditions have been measured by using the pyridine swelling technique, and the extent of crosslinking in the macromolecular network of chars was examined. The crosslinking increased with the catalysts. 02lOO576 Effect of co-combustion of sewage sludge and biomass on emissions and heavy metals behavior Spliethoff, H. er rrl. Process Saf. Environ. Prof., 2000, 78, (Bl), 33-39. Extensive investigations on co-combustion were carried out using a 0.5 MW pulverized-coal-fuelled experimental furnace with fuel preparation, accompanied by tests on an electric heated tube reactor. The following additional fuels were utilized within the framework of various projects: biomass such as wood and straw and sewage sludge. The question in focus in the case of the solid feedstock was at first the necessary fuel preparation. The outcome was that biomass (e.g. straw or wood), compared with coal, allows a clearly coarser milling due to its higher content of volatile matter. While the particle must be <1 mm for wood to completely combust, for straw they may be coarser. Regarding combustion behaviour, the major factor beside the volatile matter content is utilized grain size. The delayed ignition of coal/ biomass blends could be manifested through measurements in the flame. In the case of sewage sludge, the fine milling and the high content of volatile matter resulted in an accelerated combustion process. Co-combustion also had an effect on emission behaviour. Owing to their high volatile matter content, sewage sludge, straw and wood as suited for application in air and fuel staging with a view to nitrogen abatement. Besides the emission and combustion behaviour, the factors to be taken into account in co-combustion are the operational behaviour (slagging, fouling, corrosion) and the quality of the byproducts. 02lOO577 Effect of reaction temperature and bed depth on slow pyrolysis of coal Al-Masry, W.A. et al. J. Saudi Chem. Sot., 2000, 4, (l), 119-127. The effect of the bed depth and reaction temperature on slow pyrolysis of coal was studied. The experiments covered the range of 25-233 mm for the bed depth and 600-1000°C for the reaction temperature. Six components (i.e. CHI, CO*, CO, Hz, tar, and fixed carbon) were considered. The variation of the formation of the various volatile components with the temperature and the bed depth was discussed. A model equation that relates the yield of a particular component to the temperature and bed depth was proposed and a non-linear algorithm was employed to evaluate its associated parameters. Excellent match between predictions of the proposed model and experimental data was obtained for the various components. Such correlations can provide convenient design tool for fixed bed reactors employed in slow pyrolysis of coal. 02iOO578 Experimental study by high compression biobriquette combustion Sadakata, M. et al. Sogo Shikensho Nenpo (Tokyo Daigaku Kogakubu), 2000, 58, 177-182. (In Japanese) The combustion characteristics and desulphurization rate of biobriquettes were studied experimentally. The biobriquette was manufactured by mixing low-grade biomass, desulphurizer and denitrificater under high compression condition. The biobriquette has significant self-desulphurization and self-denitrification capabilities. The efficiency was strongly affected by coal type, and it changed from 25 to 67% for the tested types coals under the same experimental condition. 02/00579 Fluidired bed combustion of Huadian oil shale Liu, B. Ranshoo Kexue Yu Jishu, 1999, 5, (4), 448452. (In Chinese)

09 Combustion Based on the experimental study and theoretical predication, the paper introduces the fluidized bed combustion characteristics of Huadian oil shales. The basic chemical and physical properties and the ignition, combustion, burnout time, etc. of the shale, and provide a basis for large scale utilization of the oil shale. 02/00580 Forming method of pulverized coal Matsudaira, K., Nishimura, M. Jpn. Kokai Tokkyo Koho JP 2000 160,175 (Cl. ClOL5/08), 13 Jun 2000, Appl. 1998/333,595, 25 Nov 1998. 5. (In Japanese) Raw coal for manufacture of coke is prepared by mixing fine powders of coal having particle size below a fixed value and coarse powders having particle size above a fiied value at 30-90 wt.% ratio, versus the total weight of fine and coarse powders, and compressing the mixture without completely using the binder or substantially no binder used. 02/00581 Ignition processes of pulverized coal injected into preheated
(burners, combustion systems)

02lOO585 Laboratory study of trace element vaporization form combustion of pulverized coal Senior, CL. et al. Fuel Processing Technology, 2000, 63, (2-3), 109-124. Small-scale combustion experiments were conducted to study the vaoorization of trace elements durine the combustion of oulverized coil. the combustion process was samiled at high tempera&es (1423 K) corresponding to in-flame conditions. Rapid quenching and dilution oi the combusti& products were followed by a cascade impactor to collect size-segregated ash samples. Based on the comparison of concentrations of refractory elements in size-segregated ash with their bulk concentrations, we conclude that the ash having diameters less than approximately 0.4 micrometers represents the material which vaporizes during combustion in our combustion furnace. Good mass balance closure (90% to 140%) was obtained overall for ash in the sampling system. The volatile elements As, Sb, Se, and Zn showed mass balance closures significantly less than 100%. Thermochemical equilibrium predictions reported in the literature indicate that these elements should be completely volatile in the flame, although As in predicted to form condensed calcium arsenate at the sampling temperature in our system. Little chromium was found in the vaporization mode in our experiments. The uniformly low volatility of chromium suggests that chromium may react with oxides in the bulk ash. An upper bound on the amount of the more volatile elements which vaporized was computed. This upper bound accounted for the amount of the element in the finest ash and the material ‘losses’ indicated by the mass balance closure. The results of these experiments suggest almost complete vaporization of certain trace elements (Se, Zn) from coal combustion in the flame zone, in accordance with theoretical equilibrium predictions. Other elements (As, Sb) appeared considerably less volatile and may react with constituents in the bulk ash at combustion temperatures. 02/00588 Low NO, burner modifications for cost effective NO, control Melick, T.A. et al. Proc. Am. Power Conf., 2000, 62, 12-77. A review with no references of three designs available for new burners and how they are applied. Low NO, burners achieve their NO, reduction principally by control of the rate of fuel/air mixing. All of GE EERs Burner Projects were retrofits and this has required creative designs to work within the existing structure. Based on many years of low NO, burner develooment exoerience for wall fired aoolications. GE Energy and Enviroimental Rksearch Corporation (Gi ‘EER) has found that low NO. fuel/air mixing conditions can also be incorporated into conventional burners by modifying the burners as an alternative to complete burner replacement. The scope of the modificatibns is small compared to complete burner replacement, and results in a considerable savings to the utility, in many instances for similar NO, control performance. Presented is an update on GE EERs experience in applying low NO, burner modifications. This has included three 605 MWe cell-burner units, and wall fired units ranging from 17-868 MWe firing a range of coals, including Powder River Basin coals. Also discussed is the use of CFD and physical modelling techniques in the identification and resolution of flame stabilization issues experienced in certain retrofits. 02lOO587 Low NO. combustion technology for bituminous coal fired boilers Qiu, G. e/ al. Huanjing Baohu {Beijingl, 2000, 4, 10-12. (In Chinese) The formation of NO, and mechanism of NO, reduction in fractional combustion system was studied.The continuous current bituminous coal fired boiler was reformed by air fractional combustion along axial direction and radial direction. The ratio of burned out air, radial air distribution and Oz content, etc. on NO, formation and denitration efficiency was studied and optimal operation was obtained. 02/00588 Magnetizing technology for coal combustion in presence of combustion improver Piao, H. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,231,328 (Cl. ClOL9/10), 13 Ott 1999, Appl. 98,113,882, 3 Apr 1998. 5. (In Chinese) The technology comprises mixng coal, clay and fly ash, pulverizing, placing the mixture on the magnet board, dispersing the combustion improver on the material, and magnetizing for 30 min, and forming industrial coal or honeycomb briquette with the aid of magnet and agitator. The ratio of anthracite: clay and fly ash: combustion improver is (1-1.17) : (0.49-0.66) : (0.005-0.008) for honeycomb briquette, and that of industrial coal:clay and flue ash: combustion improver is (l1.06) : (0.18-0.25) : (0.0025-0.006). The combustion improver is composed of CaO 1, NaCl 0.27, urea 0.22, NH4N03 0.05, activated C 0.07, and Mn powder 0.07 part. The magnetized coal has high-heat value and no pollution. 02/00589 Mathematical description of fuel combustion grate taking into account the ecological effect Nadziakiewicz, J. Karbo, 2000, 45, (3), 91-95. (In Polish) Fuel and Energy Abstracts

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