第24卷第2期林產(chǎn)化學(xué)與工業(yè)Vol 24 No. 22004年6月Chemistry and Industry of Forest ProductsJune 2004STUDY ON INDUSTRIAL TECHNOLOGY OFGASIFICATION OF BIOMASS WITHFLUIDIZED-BEDYING Hao, JIANG Jian-chun, DAI Wei-di, LIu Shi-cai, Gao Yi-weiInstitute of Chemical Industry of Forest Products CAF Nanjing 210042 ChinaYING HAbstract: Industrial technology of gasification and catalytic gasification of biomass with inner recycled conicalfluidized bed as gasifier was discussed. Experimental results indicated that calorific value of gas from wheat strawgasification is higher than those from rice straw and husk while calorific value of gas from sawdust gasification is thehighest. Calorific value of gas from non-catalytic gasification is about 40% higher than that from down-up gasifieratalytic gasification experiment showed Cao has the effect to markedly increase calorific value and reduce thecontent of CO in gas Na, CO, has the effect to enhance the content of H,. When reaction temperature reached 800Caddition of catalytic agent can obviously enhance the gas calorific valueKey words: biomass catalytic gasification fluidized-bed gasificationCLCr:TO351.2Document code AArticle ID0253-2417(200402-0001-05生物質(zhì)流態(tài)化氣化技術(shù)研究應(yīng)浩,蔣劍春,戴偉娣,劉石彩,高一葦〔中國(guó)林業(yè)科學(xué)研究院林產(chǎn)化學(xué)工業(yè)研究所,江蘇南京210042)摘要論述了在錐形流態(tài)化氣化爐內(nèi)對(duì)生物質(zhì)原料進(jìn)行氣化和催化氣化的工程化應(yīng)用試驗(yàn)研究。研究結(jié)果表明淩草原料氣化所產(chǎn)生的煤氣熱值比稻草和稻殼都高木屑?xì)饣a(chǎn)生煤氣熱值最高非催化氣化條件下流化床氣化產(chǎn)生的煤氣熱值比下吸式氣化爐產(chǎn)生的煤氣熱值提高40%左右催化氣化試驗(yàn)發(fā)現(xiàn)CaO能明顯提高煤氣熱值、降低CO組分№aC3催化氣化能提高氣體H2的含量。但是對(duì)氣化產(chǎn)生的氣體熱值流態(tài)化空氣氣化中在710℃以下低溫時(shí)無(wú)明顯的影響當(dāng)溫度達(dá)到800℃時(shí)添加催化劑能明顯提高氣體的熱值關(guān)鍵詞泩物質(zhì)滙化氣化流化床汽氣化Fluidized-bed gasifier of biomass is a recently developering operating processsince the 70's of last century. Compared with fixed gas中國(guó)煤化工ation has the advancedmerits of evener mixed contact for gas-solid reaction whichCNMHGeed larger gas-solidReceived date 2003-10-0sBiography痖溦1963-)男浙江永康人副研究員碩士生導(dǎo)師主要從事生物質(zhì)能技術(shù)開發(fā)應(yīng)用及林產(chǎn)品化學(xué)加工工藝和工程設(shè)備設(shè)計(jì)研究衛(wèi)mailinjyingh@jlonline.com林產(chǎn)化學(xué)與工業(yè)contact area evener reaction temperature higher heat transfer coefficient higher reaction intensity of unit areaeasier operation controls shorter stay time of the reaction material in the reaction devices greater productioncity lower operation temperature and higher gasified calorific value than fixed bed gasifier -2] In recentyears researches have been paid attention to fluidized-bed technology deeplyRecycled fluidized-bed and pressure fluidized-bed have been developed respectively by researchers ofUSA, Britain Sweden Japan , India ,Germany Spain Belgium ,New Zealand Canada etc. Some of these tech-nologies have been applied in industry.The application technologies of biomass gasification have been developed in China since the 80s of lastcentury. Specially gasification system for civil cooking gas fuel have been spread in development area of ruralvillages. The gasifier that has been applied mainly is the fixed bed gasifier 51. Early in the 1990s,domesticresearches on gasification technology of recycled fluidized-bed had been carried out. However, gasificationtechnology of biomass in our country is still not advanced and the scale is small. Today reports on research ofcatalytic gasification and its industrial application are rare b.The purpose of this research is to investigate engineering adaptability of fluidized-bed gasifier designed byus using forestry residue and agriculture residue( such as sawdust straw ,rice husk etc. )as materials. Theresults of gasification experiment are discussed in this paperExperimental1.1 Raw materialsPulverizer was used to smash raw materials into granules smaller than 5 mm with the following indicescalorific values of wheat straw rice straw rice husk sawdust are 17 757, 16 317, 16 649 and 18784 kJ/krespetively the content of water( dry base )are 9.7%0 14 0% 11 5% and 13. 2% respectively1.2 Gasificationdesi technical process nner recycled fluidized bed and other equipment of biomass gasification system were1. 3 Analysis of gasGas was analyzed with a gas chromatography apparatus at testing place4 Choice of catalystsIn experiment choice of catalysts is very important. Based on laboratory test, CaO and Na, CO,werechosen as catalysts because of their good catalytic effect feasible nature and economy of industry application2 Results2.1 Gasification experimentGasification feature of sawdust rice straw heat straw and rice husk was respectively investigated. Duringthe trial processing of gasification temperature of gasification reaction was controlled by adjusting the amount ofair flow and the speed of adding raw material. Composition of gas flowing out from the gasification system wanalyzed. For different raw materials the selected feasible catalystdded into raw material before sendinto gasifier Sawdust or rice and wheat straw smashed into si中國(guó)煤化工5mm) were mixed withthe catalyst fully and evenly then they were constantly sentCNMHGgiven air flow amountwhen temperature of gasifier arrived at 600C. They were dried and decomposed quickly to carry out reactionto produce the gases such as CO, H, o,, Ha C, Hmetc2. 2 Influence of raw materialFig. I shows the influence of different kinds of raw material to gas composition at gasification reaction第2期應(yīng)浩等生物質(zhì)流態(tài)化氣化技術(shù)研究temperature of 610C. Co conent is highest for sawdust H, is highest for rice straw but C, H is highest forwheat2 gas from sawdust followed by wheat straw has highest calorific value than rice straw and ricehusk. However calorific values of the later two are still higher than those obtained from down-up gasifier offixed bed usually 15 %o higher歲8710℃610℃materialsmaterials口 rice straw;■ sawdust; Im wheat straw;團(tuán) rice huskFig 1 Effects of raw material on the component Fig. 2 Effects of raw material on the calorific valueof gas from non-catalytic gasificationof gas from non-catalytic gasification2. 3 Relation of raw materials to catalytic gasificationThere are a lot of differences on gas composition produced from catalytic gasification of diverse rawmaterials. Fig. 3 shows gas composition at two different gasifying temperatures. In this situation no matter whatkind of raw materials both contents of CO and H, are the highest the content of C, Hm is the least. This phenomenon is identical with the principle of gas-solid reaction. The content of different gas constituents is inder for CO H, CHa and C, Hm. Catalytic effect on the change of gas composition is not very notablefor the same raw material. Particularly for CO , there are slight differences between catalytic and non-catalyticgasification Content of CHA under the condition of non-catalytic gasification is high. This proved that catalysishas the effect to reduce formation of CHa. Considering the kind of raw material no matter whether catalysis isadopted gasification of sawdust is superior to rice straw. This is similar to solid reaction mechanism. Takinas gasification agent the reactions chiefly occur as followsC+O2-+C02C+O2-+2C030610℃710℃15105Na, Co, non-catalytic Cuo Na, CO, non-catalyticCaO Ne, C0, non-catalyticrice strawsawdustrice strawsawdust口H2;■C0;四CH4;囡CHFig 3 Effects of catalyst on the component of gasThe reaction begins at 350C. When temperature reaches over 500C reaction becomes completely out ofcontrol and catalysis function is lost. Addition of Na, CO, favours the reaction between H,O and C ,thus Hcontent in gas produced with catalysis is obviously higher thTH中國(guó)煤化工2.4 Calorific value of gas from catalysis gasification ofCNMHGnows the influence of catalyst to gas calorific value , under the conditions of different gasificationtemperatures. At 710C calorific value of gas by non-catalytic gasification of sawdust is a little higher thancatalysis. However at 610C the gas calorific value produced using Cao as catalyst is higher than non-catalsis. We can infer from these trial results that catalyst plays a beneficial function for pyrolysis of biomass產(chǎn)化學(xué)與工業(yè)710℃6610℃grice straw口Ca0;■Na2CO3; I non-catalyticFig 4 Effects of catalyst on calorific value of gasFig 5 shows the relation between kinds of catalyst withtures. Content of CO, was increased at 750C by addition of Na, CO,. At 710 C content of CO, was decreasedby addition of CaO. In this test change of non-catalytic gasification is fairly small between 610-800C. Gasifi-talyzed by Cao below 710C had no obvious effect on CO content in gas. However at 800C CaOplayed a function to raise the content of CO in gas. Moreover after adding Na, CO, the content of CO would bereduced64086420710710800temp /Ctemp./℃CO content :O-Ca0H2 content:-Ca0;■Na2OO3;△CO2 content i x-Ca0;-口一Na2CO3;●- non-catalytic CH4 content:x-Ca0;-kNa2OO3;-●- non-catalyticFig 5 Relationship between temperature of catalytic gasification and its content of gas from sawdustCHA and C, H are the gas components of high calorific value. In order to get gas of high calorific value thecontent of CHa and C, Hm should be raised. In Fig. 5 content of CHa under non-catalysis gasification is higherthan catalysis gasification Na, CO, possesses clearly the function of restraining the production of CHa the effectof CaO is the second Content of H, varies remarkably Na, CO, can raise the content of H, greatly. Thus it is comparatively advantageous to add Na, CO, as catalyst for producing gas rich in H, under the conditions of takias a gasification agent and using the inner recycled conical fluidized bed as gasifier. Except the decomposition ofless organic gas under high temperature the increase of H, in gas is mainly due to the addition of catalyst byreducing activation energy to accelerate the reaction between steam and carbon Content of h, is reduced underthe condition taking CaO as the catalyst probably because of occurrence of more reactions. This occurs also intheIn gasification procession with fluidized bed ,aw mater中國(guó)煤化工 perature in a very shorttime similar to flash pyrolysis which is favourable to obtainCNMH Gse However the longerstaying time in gasifier generally 10 s results in thermal decomposition of the produced gas to increase C, Hcontent In Fig. 6 calorific value of gas with CaO catalyst is higher the maximum value reaches 9 kJ/NmBoth CaO and CaCO, catalysts increase the calorific value of gas at temperature above 710C. Calorific value isobviously raised taking Cao as catalyst and reduced taking Na, CO, as catalyst應(yīng)浩等生物質(zhì)流態(tài)化氣化技術(shù)研究3 Conclusions8103. 1 Inner recycled conical fluidized bed developed by authors is an 95propriate gasifier for loose materials such as rice straw Wheat strawrice husk sawdust etc. Suitable operation temperature in central sec- 9 a0ion of gasifier is 600-820C. Adoption of the fluidized-bed can not a 6800teap./℃only resolve the difficulty for fixed gasifier to gasify materials of lowdensity and high ash content but also produce gas of higher calorificFig 6 Relationship between temperaturevalue than fixed bed gasifier for biomassof catalytic gasification and calo3.2 Calorific value of gas from wheat straw at 7716 kJ/Nm' is highrifie value of gas from sawduster than rice straw, Calorific value of gas from sawdust at 9 064 kJ/Nmis the highest3.3 Cao can obviously increase C, Hm and decrease CO in gas Na, CO, can increase H, content and decreaseCO content slightly in gas. Adoption of catalyst can effectively adjust the component of gas and reduce the content of CO. However addition of catalyst at reaction temperature below 710C has insignificant influence oncalorific value of gas. When reaction temperature is over 800C calorific value of gas is clearly increased3. 4 Inner recycled conical fluidized bed is a suitable and comparatively ideal gasifier for loose biomass.Under the condition of non-catalytic gasification ,gas of high calorific value about 40% higher than that ofdown-up gasifier of fixed bed can be obtained. Reaction temperature can be controlled convenientlyReferences1]黎強(qiáng)邱寬嶸等.流態(tài)化原理及其應(yīng)瓶M]徐州中國(guó)礦業(yè)大學(xué)岀版社1994[2 JMILES TES TR ir. Overview of biomass gasification in the USA[ J ] Biomass 1989 18: 163-1[3]張進(jìn)平蔣劍春金淳等.生物質(zhì)流態(tài)化催化氣化技術(shù)研究J]林產(chǎn)化學(xué)與工業(yè)200121(3)16[4 GERALD L, FRANCIS X J. Modern bioenergy-An overview of its prospects and potential[ J ] Renewable Energy forDevelopment 1999 124) 16-18[5正鐵林等.農(nóng)作物秸稈利用技術(shù)與設(shè)備M]北京中國(guó)農(nóng)業(yè)出版社1996[6凎金淳應(yīng)浩漲進(jìn)平等.民用木煤氣的研究J]林產(chǎn)化工通訊1995293)3-1舊◆舊◆◆舊◆◆舊◆◆舊舊◆舊◆陽(yáng)◆◆◆◆舊◆◆◆◆◆◆◆◆◆◆◆舊◆◆◆舊◆◆◆◆舊◆林產(chǎn)業(yè)廣交會(huì)”10月召開2004林業(yè)產(chǎn)業(yè)及技術(shù)應(yīng)用廣州博覽會(huì)將于2004年10月26~29日在廣州·花城(國(guó)際)展覽中心舉行。主辦單位中國(guó)林學(xué)會(huì)承辦單位疒州市今科展覽服務(wù)有限公司。博覽會(huì)設(shè)以下展會(huì)●木材、夾板、飾面板及設(shè)備專題展覽會(huì);●森林生態(tài)旅游專題展覽會(huì);紙品、紙板、紙漿及機(jī)械專題展覽會(huì);家具及木工機(jī)械專題展覽會(huì);林副產(chǎn)品、林化」林花木及木雕、根雕及機(jī)械專題展覽會(huì)。中國(guó)煤化品專題展覽會(huì);●園CNMHG聯(lián)系地址:510620廣州市體育東路33號(hào)天盛大廈?？赨154158;傳真020)87577283;E-mailjk6@163.net;聯(lián)系人杜齊華先生。