低温低压液相催化合成甲醇和甲酸甲酯用超细铜铬氧化物催化剂Ⅰ.制备条件对催化剂性能的影响

合成气制甲醇有三类催化剂.第一类是含贵金属的催化剂[1],由于其成本高,流失严重,回收困难等,致使工业上使用受到限制.第二类是Ni系催化剂[2～4],由于在使用时极易生成剧毒的Ni(CO)4化合物,既危害操作人员健康又污染环境,故工业上已逐渐弃用.第三类是Cu系催化剂[5～11],由于其低温活性高,成本低,毒性小,近年来已受到广泛重视[5～13].     

天然气化学转化新途径

21世纪初将迎来天然气能源时代,作为石油的替代资源,由天然气间接转化(经由合成气)和直接转化为液体燃料或重要化工品原料已成为人们关注的热点。本文简要介绍了80年代以来世界各国和我国有关天然气转化的各种新过程。     

非合成气法烯烃、炔烃氢甲酰化研究进展

烯烃、炔烃的氢甲酰化反应是制备醛及其衍生物的重要反应,传统的过渡金属催化合成气(CO/H2)合成法,因为价格低廉,工艺成熟,在工业上得到了广泛应用.然而合成气的高毒性、高危性限制了它的实验室研究,因此使用非合成气的氢甲酰化反应吸引了化学家的研究兴趣.采用非一氧化碳(CO)为羰基源的新型氢甲酰化研究发展迅速,我们对该领域...     

生物质气催化合成甲醇的研究

在高压微型反应装置上进行了生物质气合成甲醇的研究。利用组成为H2/CO/CO2 /N2(体积比)=52.5/21.5/22.8/3.2 的富CO2原料气考察了不同温度、压力和空速条件时甲醇的时空产率和质量分数。结果表明,在所考察的范围内,甲醇的产率和质量分数在260 ℃达到最大。产率和质量分数随反应压力升高而增大,空速增加使产率增大,甲醇的质量分数降低。当p=4 MPa,t=260 ℃,WHSV=5 280 h-1时, 甲醇的时空产率为0.79 g·（mL·h）－１,质量分数为96.2%,与工业合成气相比,分别下降25.8％和1.64％。     

Entrained Flow Gasification of Polypropylene Pyrolysis Oil

Petrochemical products could be produced from circular feedstock, such as waste plastics. Most plants that utilize syngas in their production are today equipped with entrained flow gasifiers, as this type of gasifier generates the highest syngas quality. However, feeding of circular feedstocks to an entrained flow gasifier can be problematic. Therefore, in this work, a two-step process was studied, in which polypropylene was pre-treated by pyrolysis to produce a liquid intermediate that was easily fed to the gasifier. The products from both pyrolysis and gasification were thoroughly characterized. Moreover, the product yields from the individual steps, as well as from the entire process chain, are reported. It was estimated that the yields of CO and H₂ from the two-step process were at least 0.95 and 0.06 kg per kg of polypropylene, respectively, assuming that the pyrolysis liquid and wax can be combined as feedstock to an entrained flow gasifier. On an energy basis, the energy content of CO and H₂ in the produced syngas corresponded to approximately 40% of the energy content of the polypropylene raw material. This is, however, expected to be significantly improved on a larger scale where losses are proportionally smaller.     

高硫化氢合成气制甲硫醇新型钼基催化剂研究

研究了一系列负载型钼基催化剂催化含高硫化氢合成气制甲硫醇的性能,用XPS和ESR对其进行表征.活性测试显示,钾促进的钼基催化剂催化的反应产物中甲硫醇成为主导产物.几种钼基催化剂合成甲硫醇的活性大小顺序:K₂MoO₄/CoO/SiO₂>K₂MoO₄/SiO₂>MoO₃/K₂CO₃/SiO₂>K₂MoS₄/SiO₂>MoS₂/K₂CO₃/SiO₂.ESR表征显示,反应后的催化剂可以检测到"oxo-Mo(V) "和"thio-Mo(V)"物种.XPS表征显示反应后催化剂中的Mo包含着Mo⁴⁺,Mo⁵⁺和Mo⁶⁺,S包含着S^2-,(S-S)^2-和S⁶⁺三种价态.添加CoO后,"oxo-Mo(V)"含量减少,而"thio-Mo(V)"含量增加,(S-S)^2-物种的生成得到抑制,S^2-物种的量增多.(Mo⁴⁺+Mo⁵⁺)/Mo⁶⁺峰强度比为0.75以及S^2-/(S-S)^2-接近1有利于甲硫醇的生成.本文提出甲硫醇的合成与"Mo-S-K"相关联的反应机理.