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题名	钴基催化剂催化生物质合成气F-T合成的实验研究; Experiment Study of Fischer-Tropsch Synthesis from Biomass Syngas over Cobalt-based Catalysts
作者	覃欣欣
学位类别	硕士
答辩日期	2009-05-31
授予单位	中国科学院广州能源研究所
授予地点	广州能源研究所
导师	王铁军
关键词	生物质合成气 钴基催化剂 F-T合成 锰助剂
其他题名	Experiment Study of Fischer-Tropsch Synthesis from Biomass Syngas over Cobalt-based Catalysts
中文摘要	Biomass energy is the forth in the world total energy consumption, coming only after coal, oil, and natural gas. As a carbon resource, biomass not only can be used for heat and power generation, but it also is the only renewable energy which can be converted into liquid fuels or chemicals. Compared to the first generation biofuels the second generation biofuels have greater prospects for development, because the feedstocks are non-food crops and are more stable in supply. Biomass indirect liquefaction through gasification is regarded as the most efficient way of utilizing biomass. The FTS (Fischer-Tropsch synthesis) is a commonly used reaction in organic chemical, which is taking coal, oil or natural gas as feedstocks. FTS is the basic principle of BTL (biomass to liquid) process and produces hydrocarbons of different length from a gas mixture of H2 and CO (syngas) from biomass gasification. At present, FTS using coal and natural gas is almost a well-established technology. However, as for FTS from biomass-derived syngas, it is still limited in laboratory stage. It is significant in science and practice to research & development proper catalyst systems and FTS processes for the biomass derived syngas. The aim of the present work is to study the FTS of biomass derived syngas on traditional FTS catalysts, and to improve the conversion by adding promoters, including: (1) under typical FTS reaction condition, comparing the reaction performances of industrial syngas (H2/CO=2) and biomass syngas (H2/CO=1, containing CO2) over traditional FTS catalyst, in a fixed bed microreactor; (2) investigating the effect of manganese promoter with different loadings on the conversion and product distribution of the syngas; (3) characterizing the catalysts by XRD, H2-TPR, and TGA-FTIR. The results obtained are listed as follows: 1. FT reactions were carried out under 240oC, 2.0MPa, 1000h-1, using industrial syngas and biomass syngas as feedgas.It was found that (1) the 20wt% Co/SiO2 catalyst used had higher activity and the CO conversion of the industrial syngas was over 90%; (2) FTS from the biomass syngas is possible to obtain liquid hydrocarbons over Co/SiO2 catalyst, and the selectivity of CH4 is lower. However, the CO conversion of biomass syngas (less than 30%) is much lower than that of industrial syngas. The product of biomass syngas tended to be higher carbon number hydrocarbons, and the selectivity of C5+ was 80.62%. The average yield of C5+ after 24h-reaction was 131.30g/m3(syngas). 2. The Co/SiO2 catalyst was promoted by impregnation with different amounts of manganese (0.4, 0.8, 1.5, 2.0, 5.0, and 7.0 wt%). (1) It was shown by XRD and H2-TPR that Mn made the particle size of Co3O4 be smaller and hampered the reduction of Co3O4 to Co0, which probably was caused by formation of CoMn oxides. (2) FT catalytic test revealed that small amount of Mn (0.4%, 0.8%) could increase the CO conversion and selectivity of C5+. On the cobalt catalyst promoted by 0.8% Mn, the CO conversion of biomass syngas was the highest (52.55%) and CH4 selectivity is lower(9.93%). Loading of more than 0.8% Mn resulted in a decrease in activity and C5+ selectivity and an increase in olefin content in light hydrocarbons. (3) Stability of the cobalt catalyst in the atmosphere of biomass syngas was improved by adding Mn. The average CO conversion after 24h-reaction was increased from 29.13% (over Co/SiO2) to 42.38% (over Co-(0.8%)Mn/SiO2).The average selectivity of C5+ hydrocarbons was 78.99%, and the average yield was 154.9g/m3(syngas) (4) The average flux of the off-gas accounted for about 50% of the syngas. Based on the composition, the heat value of the FT off-gas of biomass syngas over Co-(0.8%)Mn/SiO2 is about 14.54 MJ/m3. Deposition of carbon and small amount of heavy hydrocarbons on the catalysts surface was one of the possible reasons for the catalyst deactivation.
语种	中文
公开日期	2011-07-10 ; 2011-07-15
页码	79
内容类型	学位论文
源URL	[http://ir.giec.ac.cn/handle/344007/4029]
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	覃欣欣. 钴基催化剂催化生物质合成气F-T合成的实验研究, Experiment Study of Fischer-Tropsch Synthesis from Biomass Syngas over Cobalt-based Catalysts[D]. 广州能源研究所. 中国科学院广州能源研究所. 2009.

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