农业工程学报
農業工程學報
농업공정학보
2014年
20期
252-258
,共7页
李攀%王贤华%邵敬爱%杨海平%陈汉平
李攀%王賢華%邵敬愛%楊海平%陳漢平
리반%왕현화%소경애%양해평%진한평
生物质%热解%催化剂%产物特性
生物質%熱解%催化劑%產物特性
생물질%열해%최화제%산물특성
biomass%pyrolysis%catalysts%product property
为考察对于氢型分子筛(HZSM-5)的Si/Al变化和添加量对生物质热解液化的影响,该文通过离子交换法制备HZSM-5催化剂,采用激光粒度分析仪、比表面积及孔径分析仪和X射线衍射仪对催化剂的粒度、孔隙及晶体结构等性质进行表征,并在最佳油产率温度下进行木屑的催化热解。对无催化剂和不同催化条件下得到的生物油进行气相色谱质谱联用分析,结果表明,分子筛作用下,生物油产率明显降低(最大降幅8%),含水率增加。同时,液体产物中醛类、酯类、酮类、呋喃等含氧化合物及酸含量均有所降低,提高了烃类和酚类的含量,峰面积百分比最高达到12.57%和39.36%,对催化剂催化调控改善生物油品质提供了一定的科学依据。
為攷察對于氫型分子篩(HZSM-5)的Si/Al變化和添加量對生物質熱解液化的影響,該文通過離子交換法製備HZSM-5催化劑,採用激光粒度分析儀、比錶麵積及孔徑分析儀和X射線衍射儀對催化劑的粒度、孔隙及晶體結構等性質進行錶徵,併在最佳油產率溫度下進行木屑的催化熱解。對無催化劑和不同催化條件下得到的生物油進行氣相色譜質譜聯用分析,結果錶明,分子篩作用下,生物油產率明顯降低(最大降幅8%),含水率增加。同時,液體產物中醛類、酯類、酮類、呋喃等含氧化閤物及痠含量均有所降低,提高瞭烴類和酚類的含量,峰麵積百分比最高達到12.57%和39.36%,對催化劑催化調控改善生物油品質提供瞭一定的科學依據。
위고찰대우경형분자사(HZSM-5)적Si/Al변화화첨가량대생물질열해액화적영향,해문통과리자교환법제비HZSM-5최화제,채용격광립도분석의、비표면적급공경분석의화X사선연사의대최화제적립도、공극급정체결구등성질진행표정,병재최가유산솔온도하진행목설적최화열해。대무최화제화불동최화조건하득도적생물유진행기상색보질보련용분석,결과표명,분자사작용하,생물유산솔명현강저(최대강폭8%),함수솔증가。동시,액체산물중철류、지류、동류、부남등함양화합물급산함량균유소강저,제고료경류화분류적함량,봉면적백분비최고체도12.57%화39.36%,대최화제최화조공개선생물유품질제공료일정적과학의거。
In order to investigate the effect on biomass liquefaction of HZSM-5 zeolite under different silica to alumina ratio and adding amounts. The HZSM-5 (hydrogen zeolite) catalysts obtained by ion-exchange method were characterized using laser particle size analyzer, specific surface area and pore size analyzer with Brunauer-Emmett-Teller (BET) method and X-ray diffraction (XRD), and applied for the catalytic pyrolysis of wood at the optimum temperature of best oil yield. The bio-oils obtained from direct liquefaction with and without catalysts were characterized by GC-MS (Gas Chromatograph-Mass Spectrometer) analyses. The results indicated that: Compared with ZSM-5 zeolite, the crystal grain size of HZSM-5 zeolite prepared through ion exchange increased, and the particle size distribution was more concentrated, andthe catalyst had a preferable crystalline tacticity and a increased crystallinity, meanwhile, the surface area and the pore volume of HZSM-5 catalyst decreased, while pore size did not change significantly. When the HZSM-5 zeolite of different silica to alumina ratio were applied to pyrolysis, the yield of bio-oil decreased significantly (the maximum was up to 8%), the moisture content of the bio-oil increased. However, the composition of bio-oil and the relative content of the product changed a lot, it indicated that there was obvious catalytic effects during the direct liquefaction of biomass under HZSM-5 zeolite. Compared with non-catalyst pyrolysis, the contents of aldehydes, esters, ketones, furans and acid (oxygenated compounds) were reduced. It showed that HZSM-5 zeolite promoted a series of decarboxylation, decarbonylation reaction during the pyrolysis process, resulted to the reduction of the oxygen content of bio-oil and helped to improve the stability of bio-oil. With the increasing of silica to alumina ratio, the catalytic activity weakened a little. When the adding amounts of HZSM-5 zeolite were increased, a small variation of the yield of bio-oil occured, the moisture content of the bio-oil continued to go up, while the content of oxygen-containing compounds and acid aldehydes, esters, ketones, furans further reduced, promoting the formation of hydrocarbons, phenols, alcohols, the maximum percentage of the peak area could be up to 12.57% and 39.36%. Because HZSM-5 zeolite help to provide rich aperture on the surface, which was conducive to the formation of positive carbon ions, then the products of the first thermal decomposition carried on isomerization, cracking formation to convert as small molecules alkanes and alkenes, then go through polymerization reaction, cyclization reaction and a series of reactions to generate aromatic substances and so on. Owing to the above reaction procedure, there was a greater overall increasing in hydrocarbon substances. After the addition ratio was greater than 10%, the changing rate of various components decreased. Comprehensive analysis results of the type and amount of added catalyst showed that HZSM-5 (25) zeolite with the addition ratio of 10% played a more significant role on the catalytic liquefaction control of wood dust.