【作者】 张洪敏；

【导师】 周小平；

【作者基本信息】 湖南大学 ， 化学工艺， 2008， 硕士

【摘要】 目前,天然气制高碳烃液体燃料主要是从合成气出发,经费-托合成转化生成。但是,在天然气水蒸汽重整制合成气的过程中,需要消耗掉四分之一以上的天然气来供给反应热量,能量消耗大,造成资源的巨大浪费。本实验室设计的天然气经非合成气途径合成高碳烃的新工艺流程,可以有效地将甲烷等低碳烃转化为高碳烃,能耗和CO2排放大幅降低。新工艺流程包括两步反应:第一步,甲烷通过与氢溴酸和氧气的反应转化成溴甲烷;第二步,溴甲烷脱溴化氢制高碳烃,溴化氢循环使用。本文主要是对溴甲烷脱溴化氢制高碳烃的催化剂进行研究。实验中所使用的溴甲烷原料是由氢溴酸和无水甲醇混合液在HZSM-5催化剂上生成的。论文在自制的固定床反应器中开展溴甲烷脱溴化氢制高碳烃催化剂的研究,主要考察了分子筛载体、MgO或ZnO负载量、反应温度（200°C～300°C）、空速等因素对反应的影响,考察了几种典型催化剂的寿命,并在GC-MS （Agilent 6890N/5973N）上对气体、液体产物进行了定性定量分析。结果表明:HZSM-5负载的ZnO、MgO是溴甲烷转化的最好催化剂,ZnO、MgO的最佳含量在1.0⁵.0wt%之间;温度升高有利于溴甲烷的转化,升至260°C³00°C时,溴甲烷的转化率趋于稳定,高达99.7% ;气相、液相产物的组成也随温度的升高而变化,在3.0wt%ZnO/HZSM-5催化剂上高温有利于芳烃的生成,在3.0wt%MgO/HZSM-5催化剂上,温度升高时低碳烃选择性高;MgO/HZSM-5较ZnO/HZSM-5催化剂具有更好的稳定性,连续反应近一个月效率仍然较高。产物的主要组成是C₂～C₁₃的烷烃、烯烃和芳烃。更多还原

【Abstract】 Recent years, the major process for the conversion of natural gas to liquid fuels is initially from syngas, which is called Fischer-Tropsch process. But it is an energy consuming and resource wasting process. More than one fourth of the natural gas must be burned to generate heat for the steam reforming of the raw material. Here, we designed a new process in which higher hydrocarbons can be synthesized from non-syngas and the process is effective to convert methane and other low-carbon hydrocarbons into higher hydrocarbons. Meanwhile, the energy consumption and CO2 emissions are substantially reduced. In the process, the first step was to convert methane to methyl bromide by the reaction of methane with hydrogen bromide and oxygen, then, higher hydrocarbons were produced by the condensation of methyl bromide in the second step. The produced hydrogen bromide can be recycled. By this method, methane could be high efficiently converted to higher hydrocarbons.This paper mainly developed the catalysts of methyl bromide catalytic dehydrobromination to prepare higher hydrocarbons in the self-made fixed-bed reactor. In the experiments, methyl bromide was generated by the reaction of the mixture of hydrobromic acid and methanol on HZSM-5 catalyst. In the current investigation, the influence of zeolite carriers, MgO or ZnO concentrantion, reaction temperature（200°C～300°C） and space velocity on CH3Br conversion was tested. In addition, the aging reaction of several typical catalysts was investigated; the qualitative and quantitative analysis of all products in gas and liquid phase was performed on GC-MS （Agilent 6890N/5973N）. The results were that on the HZSM-5 supported MgO or ZnO catalysts, MgO and ZnO concentration between 1.0wt% and 5.0wt% were the best; higher temperature was favor to CH3Br reaction, when the temperature was up to 260°C³00°C, CH3Br conversion would be stable, 99.7% the highest; the constitute of gas and liquid phase products changed with the temperature increasing: on 3.0wt% ZnO/HZSM-5 catalyst, higher temperature was favor to the aroma, while to the lower hydrocarbons on 3.0wt% MgO/HZSM-5 catalyst; the catalyst MgO/HZSM-5 was better than ZnO/HZSM-5 because the former showed better activity at lower temperature and better stability, which could keep higher CH3Br conversion in one month. The major components of the products were alkanes, olefins and aromatic compounds with carbon number in the region of C₂ to C₍13_.更多还原