生物质气一步法合成LPG催化剂及工艺研究

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	生物质气一步法合成LPG催化剂及工艺研究
其他题名	Experimental Study on the Catalyst and Techniques for the Direct Synthsis of LPG from Biomass Synthesis Gas
	吕永兴
导师	王铁军
	2008-06-03
学位授予单位	中国科学院广州能源研究所
学位授予地点	广州能源研究所
学位名称	硕士
关键词	生物质合成气液化石油气双功能催化剂 Hzsm-5型分子筛
摘要	随着化石燃料储量的减少和燃烧化石燃料导致的全球环境问题加剧，寻求一种可再生的石油代替品引起了全球性的关注。生物质具有可再生性、相对比较廉价、高效率转化和洁净等优点，对生物质进行开发利用具有极大的现实意义。利用生物质合成气一步法合成液化石油气（LPG），具有效率高、成本低、经济效益良好等优点，是对生物质进行利用最有前景的方法之一，具有十分重要的社会意义。本文以提高生物质气一步法合成液化石油气转化率为目标，首先展开了对合成液化石油气催化剂的研究。研究主要包括以下三个方面：（1）研究HZSM-5和USY型分子筛对合成液化石油气的影响，筛选更适合合成液化石油气的脱水催化剂为HZSM-5型分子筛；（2）通过对HZSM-5型分子筛不同硅铝比，双功能催化剂中不同含量作出进一步研究，筛选出硅铝比为38的HZSM-5型分子筛效果最佳；（3）通过利用MgO对HZSM-5型分子筛进行改性，得出含MgO0.25%~1%的HZSM-5型分子筛的效果最佳。实验中液化石油气合成装置在微型积分反应器上进行，催化剂的表征手段为NH3-TPD、XRD等。主要研究结果如下： 1. 通过对脱水催化剂HZSM-5和超稳USY型分子筛的研究，表明HZSM-5型分子筛效果明显高于超稳USY型分子筛。合成液化石油气过程中，HZSM-5型分子筛最佳反应温度为325℃，而超稳USY型分子筛为340℃。同时也表明，HZSM-5型分子筛脱水性能和对C3、C4选择性能上都优于超稳USY型分子筛。 2. 对HZSM-5在合成LPG催化剂中含量不同和Si/Al比值的研究。结果表明：甲醇合成催化剂与HZSM-5最佳质量配比为2：1；CO转化率随HZSM-5的Si/Al比值的降低而升高；HZSM-5酸性强弱为Cat25＞Cat38＞Cat50；C3+C4时空产率规律为Cat38＞Cat25＞Cat50。HZSM-5型分子筛在合成LPG过程中，硅铝比为38时最佳，其对C3+C4的选择性及时空产率达到最佳。 3. 通过NH3-TPD测试得出，改性的HZSM-5随MgO含量的增加，高温强酸B酸量减少，而低温峰几乎无变化。证明MgO的加入，主要影响的是HZSM-5中的B酸。研究结果表明，含0.25%~1% MgO的HZSM-5作为脱水催化剂时，合成LPG的效果最佳，同时也表明适量的添加MgO可以提高催化剂的稳定性，延长催化剂的使用寿命。
其他摘要	With declining reserves of fossil fuels and the threat of global climate deterioration caused largely by the combustion of fossil fuels, the search for a renewable substitute as raw material to replace petroleum has been intensified all over the world. Since biomass feedstock is clean, cheap and renewable, the developments and utilizations of the biomass resoures are prospective in the future. The process of direct synthsis Liquefied Petroleum Gas (LPG) highly efficient and low-cost, has already been suggested as a way of utilizing biomass and has great economical and social effects. In this paper, for the high conversion of biomass syngas to LPG, the catalyst for the direct LPG synthesis is investigated. Research includes the following three aspects: (1) the effect of HZSM-5 zeolite and USY zeolite on direct synthesis LPG; (2) the effect of Si/Al ratio of HZSM-5 zeolite on the direct LPG synthesis; (3) the effect of MgO modified HZSM-5 zeolite on the direct LPG synthesis. The catalyst test of LPG synthesis from biomass syngas were carried out in an integral micro-reactor and the catalysts were characterized by the means of NH3-TPD and XRD. The major results are: 1. The research results show that HZSM-5 zeolite was significantly better than ultra-stable USY zeolite. In the process of LPG synthesis, the best reaction temperature of HZSM-5 is 325℃，but Ultra-stable USY zeolite is 340℃. It also shows that dehydration and the selectivity to C3+C4 of HZSM-5 zeolite is better than that of ultra-stable USY zeolite. 2. The hybrid catalyst consists of methanol synthesis catalyst and HZSM-5 zeolite, which demonstrated a highly effective formation when the mass ratio of methanol synthesis catalyst and HZSM-5 zeolite is 2:1. The results show that the CO conversion is increased with the decrease of Si/Al ratio. The acidity of the HZSM-5 with Si/Al value is Cat25＞Cat38＞Cat50. The space time yield of C3+C4 with Si/Al value is Cat38＞Cat25＞Cat50. According to our study, with Si/Al ratio of 38, the selectivity to C3+C4 and the space time yield of C3+C4 can reach the best value respectively. 3. NH3-TPD characterization results showed that with the increase in MgO content, HZSM-5 zeolite reduced the amount of B-acid, but the low-temperature peaks almost unchanged. The results showed that the effect of LPG synthesis is the best when containing 0.25%~1% MgO of HZSM-5 zeolite is a dehydration catalyst of LPG snthesis catalyst. It also shows that moderate addition of MgO can improve the stability of catalysts and catalyst life.
页数	67
语种	中文
文献类型	学位论文
条目标识符	http://ir.giec.ac.cn/handle/344007/5820
专题	中国科学院广州能源研究所
推荐引用方式 GB/T 7714	吕永兴. 生物质气一步法合成LPG催化剂及工艺研究[D]. 广州能源研究所. 中国科学院广州能源研究所,2008.

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