摘要
针对热解挥发物直接燃烧作为分布式热解制炭热源工艺,以消除生物质热解挥发物中炭颗粒、提高其品质,改善其燃烧性能为目的,利用自制生物质螺旋连续热解反应器和热解挥发物贫氧调质反应器,采用贫氧燃烧方式进行了热解挥发物原位调质试验研究,分析了调质温度、空气量对挥发物组分的影响。结果表明:生物质热解挥发物中携带炭颗粒粒径为1~2μm,在调质温度350℃和空气量20 m L/min条件下,已很难收集到炭颗粒,原位贫氧调质可以消除热解挥发物中炭颗粒;贫氧调质对气相产物组分含量影响不明显,主要组分H2、CO2的变化均在±5%范围内,CO、CH4变化在±2%范围内;随着贫氧调质温度升高和空气量加大,重质组分中的烷类物质含量显著降低,酚类物质显著增加,呋喃、醇、茚、醛等次要组分含量略有增加,低碳原子数物质含量增加,高碳原子数物质含量降低;轻质产物中烷类、酸类、酮类和酚类物质相对含量发生显著变化,酚类物质性质较稳定,实际含量变化不明显,调质后低碳原子数物质含量增加。原位贫氧调质可以消除热解挥发物中炭颗粒,降低热解挥发物中重质组分含量,从而改善热解挥发物的燃烧性能,为热解挥发物直接燃烧作为分布式热解制炭的热源提供科学依据。
With regard to the distributed bio-char production technology that combusting pyrolysis volatiles for its heat resource,and aimed at eliminating charcoal particles,decreasing heavy components and increasing light components in pyrolysis volatiles,thereby improving the combustion characteristics of pyrolysis volatiles,by using an auger reactor for continuous pyrolysis of biomass and an oxygen-lean conditioning reactor for pyrolysis volatiles,with the stoichiometric air rate of combusting charcoal particles in pyrolysis volatiles as the basis,the experimental study on in-situ oxygen-lean conditioning on biomass pyrolysis volatiles was carried out. The influences of conditioning temperatures and air rates on the components of pyrolysis volatiles were analyzed. The experimental conditions were as follows： pyrolysis temperature of 550℃,biomass feeding rate of 527 g/h,pyrolysis residential time of 10 min,and the control temperature for charcoal tank was 250℃; the conditioning temperatures were 350℃,400℃,450℃ and 500℃,respectively,and the air rates were 20 m L/min,40 m L/min,60 m L/min and80 m L/min,respectively. The results showed that the particle size of charcoal in the pyrolysis volatiles was 1 ~ 2 μm,and it was difficult to collect the particles at the conditioning temperature of 350℃ with air rate of 20 m L/min,in-situ oxygen-lean conditioning may eliminate the charcoal particles in pyrolysis volatiles; in-situ oxygen-lean conditioning had less influences on the gas components of pyrolysis volatiles,the changing rates of H2 and CO2 were all within ± 5%,the influences were even weak for CO and CH4 whose changing rates were within ± 2%; along with the elevating of conditioning temperature and the increase of the air rate,the contents of alkyl group chemicals in the heavy components of pyrolysis volatiles showed obvious decrease while the phenols showed evident increase,a little bit ofincrease in contents was found for the lower-content chemicals such as furans,alcohols,indenes and aldehydes. The contents of lower carbon compounds were increased while the higher carbon compounds were decreased; the relative contents of alkyl group,acids,ketones and phenols in light components of pyrolysis volatiles showed obvious changes,and the changes of phenols ＇ absolute contents were not obvious due to their chemical stabilities,similar to that in the heavy components of pyrolysis volatiles,the lower carbon compounds in light components of pyrolysis volatiles had also shown increases. Due to the feasibility of eliminating the charcoal particles, decreasing heavy components and increasing light components in pyrolysis volatiles, in-situ oxygen-lean conditioning may improve the combustion characteristics of pyrolysis volatiles,the research results could be used as reference for distributed biochar production which pyrolysis volatiles were combusted for pyrolysis.
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2017年第11期330-337,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
广东省科技计划重大项目(2015B020237010)
关键词
生物质
热解
挥发物
原位
贫氧调质
biomass
pyrolysis
voIatiles
in-situ
oxygen-lean conditioning
