SMALE established a famous horseshoe model,which shows that there exists a phe-nomenon of chaos in some self-homeomorphisms of discs on the plane although these homeo-morphisms are not very complex.A main conclusion o...SMALE established a famous horseshoe model,which shows that there exists a phe-nomenon of chaos in some self-homeomorphisms of discs on the plane although these homeo-morphisms are not very complex.A main conclusion on the Smale horseshoe is as follows.展开更多
Fractional pyrolysis and one-step pyrolysis of natural algae Cyanobacteria from Taihu Lake were comparatively studied from 200 to 500 ℃. One-step pyrolysis produced bio-oil with complex composition and low high heati...Fractional pyrolysis and one-step pyrolysis of natural algae Cyanobacteria from Taihu Lake were comparatively studied from 200 to 500 ℃. One-step pyrolysis produced bio-oil with complex composition and low high heating value （HHV〈30.9 MJ/kg）. Fractional pyrolysis separated the degradation of different components in Cyanobacteria and improved the selectivity to products in bio-oil. That is, acids at 200 ℃, amides and acids at 300 ℃, phenols and nitriles at 400 ℃, and phenols at 500 ℃, were got as main products, respectively. HZSM-5 could promote the dehydration, cracking and aromatization of pyrolytic intermediates in fractional pyrolysis. At optimal HZSM-5 catalyst dosage of 1.0 g, the selectivity to products and the quality of bio-oil were improved obviously. The main products in bio-oil changed to nitriles （47.2%） at 300 ℃, indoles （51.3%） and phenols （36.3%） at 400 ℃. The oxygen content was reduced to 7.2 wt% and 9.4 wt%, and the HHV was raised to 38.1 and 37.3 MJ/kg at 300 and 400 ℃, respectively. Fractional catalytic pyrolysis was proposed to be an efficient method not only to provide a potential solution for alleviating environmental pressure from water blooms, but also to improve the selectivity to products and obtain high quality bio-oil.展开更多
This work aims to investigate the intrinsic kinetics of thermal dimerization of C_5 fraction in the reactive distillation process. Experiments are conducted in an 1000-m L stainless steel autoclave under some selected...This work aims to investigate the intrinsic kinetics of thermal dimerization of C_5 fraction in the reactive distillation process. Experiments are conducted in an 1000-m L stainless steel autoclave under some selected design conditions. By means of the weighted least squares method, the intrinsic kinetics of thermal dimerization of C_5 fraction is established, and the corresponding pre-exponential factor as well as the activation energy are determined. For example, the pre-exponential factor A is equal to 4.39×105 and the activation energy E4 a is equal to 6.58×10J/mol for the cyclopentadiene dimerization reaction. The comparison between the experimental and calculated results shows that the kinetics model derived in this work is accurate and reliable, which can be used in the design of reactive distillation columns.展开更多
利用隔壁精馏塔替代混合碳五馏分原有分离流程中的脱丁烷塔和碳五预分离塔,通过Aspen Plus V12软件对混合碳五馏分的提纯流程进行稳态模拟,在此基础上运用灵敏度分析工具,对隔壁精馏塔的操作参数进行优化。结果表明:采用隔壁精馏塔替代...利用隔壁精馏塔替代混合碳五馏分原有分离流程中的脱丁烷塔和碳五预分离塔,通过Aspen Plus V12软件对混合碳五馏分的提纯流程进行稳态模拟,在此基础上运用灵敏度分析工具,对隔壁精馏塔的操作参数进行优化。结果表明:采用隔壁精馏塔替代脱丁烷塔和碳五预分离塔,最佳原料进料位置为第11块塔板、最佳质量回流比为5、最佳侧线采出位置为第7块塔板、最佳侧线采出量为500 kg h,气相回流位置为第37块塔板,液相回流位置为第12块塔板;在相同进料条件和相同碳五馏分纯度的前提下,与采用常规精馏工艺相比,采用隔壁塔精馏工艺时冷却能耗降低17.04%,加热能耗降低16.69%。展开更多
文摘SMALE established a famous horseshoe model,which shows that there exists a phe-nomenon of chaos in some self-homeomorphisms of discs on the plane although these homeo-morphisms are not very complex.A main conclusion on the Smale horseshoe is as follows.
基金supported by the National Basic Research Program of China(973 Program,No.2013CB228103)
文摘Fractional pyrolysis and one-step pyrolysis of natural algae Cyanobacteria from Taihu Lake were comparatively studied from 200 to 500 ℃. One-step pyrolysis produced bio-oil with complex composition and low high heating value （HHV〈30.9 MJ/kg）. Fractional pyrolysis separated the degradation of different components in Cyanobacteria and improved the selectivity to products in bio-oil. That is, acids at 200 ℃, amides and acids at 300 ℃, phenols and nitriles at 400 ℃, and phenols at 500 ℃, were got as main products, respectively. HZSM-5 could promote the dehydration, cracking and aromatization of pyrolytic intermediates in fractional pyrolysis. At optimal HZSM-5 catalyst dosage of 1.0 g, the selectivity to products and the quality of bio-oil were improved obviously. The main products in bio-oil changed to nitriles （47.2%） at 300 ℃, indoles （51.3%） and phenols （36.3%） at 400 ℃. The oxygen content was reduced to 7.2 wt% and 9.4 wt%, and the HHV was raised to 38.1 and 37.3 MJ/kg at 300 and 400 ℃, respectively. Fractional catalytic pyrolysis was proposed to be an efficient method not only to provide a potential solution for alleviating environmental pressure from water blooms, but also to improve the selectivity to products and obtain high quality bio-oil.
文摘This work aims to investigate the intrinsic kinetics of thermal dimerization of C_5 fraction in the reactive distillation process. Experiments are conducted in an 1000-m L stainless steel autoclave under some selected design conditions. By means of the weighted least squares method, the intrinsic kinetics of thermal dimerization of C_5 fraction is established, and the corresponding pre-exponential factor as well as the activation energy are determined. For example, the pre-exponential factor A is equal to 4.39×105 and the activation energy E4 a is equal to 6.58×10J/mol for the cyclopentadiene dimerization reaction. The comparison between the experimental and calculated results shows that the kinetics model derived in this work is accurate and reliable, which can be used in the design of reactive distillation columns.
文摘利用隔壁精馏塔替代混合碳五馏分原有分离流程中的脱丁烷塔和碳五预分离塔,通过Aspen Plus V12软件对混合碳五馏分的提纯流程进行稳态模拟,在此基础上运用灵敏度分析工具,对隔壁精馏塔的操作参数进行优化。结果表明:采用隔壁精馏塔替代脱丁烷塔和碳五预分离塔,最佳原料进料位置为第11块塔板、最佳质量回流比为5、最佳侧线采出位置为第7块塔板、最佳侧线采出量为500 kg h,气相回流位置为第37块塔板,液相回流位置为第12块塔板;在相同进料条件和相同碳五馏分纯度的前提下,与采用常规精馏工艺相比,采用隔壁塔精馏工艺时冷却能耗降低17.04%,加热能耗降低16.69%。
