甲醇合成铜基催化剂中毒失活评述

阐述了甲醇合成铜基催化剂的活性机理,常见毒物如硫、氯、油、氨、金属羰基化合物等对铜基催化剂的毒害机理。并就预防失活的措施及新型甲醇合成催化剂的开发提出了建议。     

脱羰基金属、脱氯、脱氨和脱油技术及其在甲醇工业中的应用（下）

2氯及氯的化合物 2．1氯对甲醇催化剂的中毒作用 氯有未成键孤对电子，并有很大的电子亲和力，易与金属离子反应，氯离子还具有很高的迁移性，常随工艺气向下游迁移，对氯中毒催化剂分析表明，上下床层氯含量几乎无浓度梯度，中毒是不分层的，其造成催化剂中毒往往是全床层性的。表4是几例失活甲醇催化剂中氯含量。     

甲醇钾合成方法研究进展及应用

介绍了甲醇钾的传统合成方法及目前国内外制备甲醇钾的最新研究进展,重点概述了钾金属及钾金属化合物与甲醇反应制备甲醇钾以及钾金属化合物与甲醇的有机盐反应生成甲醇钾两个研究方向的最新进展,并简介了甲醇钾的应用情况。     

影响甲醇合成的因素

甲醇是重要的有机化工原料和优质燃料。主要用于制造甲醛、醋酸、氯甲烷、甲氨、硫酸二甲脂等多种有机产品,也是农药、医药的重要原料之一。甲醇亦可代替汽油作燃料使用。本文通过甲醇合成的发展历史和合成技术的阐述,讨论了影响甲醇合成的几个重要因素,对甲醇生产有指导意义。     

1-苄氧基-3-丁烯-2-酮的合成研究

设计合成了标题化合物,以二甲醇缩氯乙醛为起始原料,通过亲核取代、脱保护基、Grignard反应和氧化合成了目标产物,总收率50.4%.产品的结构经1HNMR、13CNMR和高分辨质谱确证.     

甲醇液氯法联产氯代甲烷的工艺特点及其发展前景

介绍了以甲醇、液氯为原料的两步反应法生产氯代甲烷,即甲醇气相催化生产一氯甲烷和一氯甲烷液相催化生产其他氯代甲烷的工艺特点及其发展前景。     

甲醇合成催化剂保护剂

据统计我国甲醇生产厂已达200多家,并仍在继续增加,所用甲醇合成催化剂为铜基催化剂。该类催化剂活性高、选择性好、操作条件温和、但对于原料气的纯度要求较高,特别是对硫、铁、镍和氯等杂质非常敏感,极易引起甲醇合成催化剂的失活,硫及氯对催化剂的影响已引起广大厂家的高度重视,而羰基铁、镍由于受分析条件限制,被广大厂家所忽视,脱除原料气中的羰基铁、镍能有效地延长甲醇合成催化剂的寿命,降低粗甲醇中的杂质含量,降低生产成本,使生产管理登上一个新的台阶。     

氯对氮肥和甲醇生产的危害及其脱除

详细介绍了氮肥和甲醇生产中氯的来源、危害及其脱除方法。     

2,4-二氯-α-氯甲基苯甲醇的合成研究

2,4-二氯-α-氯甲基苯甲醇是合成硝酸咪(益)康唑、抑霉唑等的重要中间体,具有非常广泛的用途。参考了国内有关2,4-二氯-α-氯甲基苯甲醇合成的文献,综述了我国2,4-二氯-α-氯甲基苯甲醇的合成研究,提出了孔分子筛中负载金属氧化物、手性配体等活性组分将是今后研究发展的主要方向。     

谈天然气转化利用技术的研究进展

主要评述了自1995年以来，全球天然气转化利用商业化技术的重大进展，包括合成气生产、天然气制合成油、含氧化合物生产（主要是甲醇和二甲醚）、甲醇制烯烃。综述了甲烷脱氢芳构化反应制苯、部分氧化制甲醇、氧化偶联制乙烯的研究进展，并对发展我国天然气化工提出建议。     

低压恒温甲醇合成系统的设计及应用

论述了低压恒温甲醇合成系统工艺流程的特点,介绍了水管式甲醇合成塔内件的结构形式和选型方案;通过生产运行数据分析,总结了低压恒温水管式甲醇合成塔的应用效果。     

甲醇代替石油燃料的可行性分析

介绍了甲醇生产的技术与生产状况,指出了国内甲醇生产行业存在的问题主要集中于甲醇生产企业规模较小,产能较低;企业开工率低以及甲醇生产的增长速度超过了市场需求量的增长速度等方面并简要分析了原因。介绍了全球石油的需求情况,分析了甲醇代替石油燃料的可行性以及甲醇汽油在中国发展的优势和未来市场前景并进行了展望。     

合成甲醇催化剂的研究进展

介绍了国内外合成甲醇催化剂的研究情况;从性能参数、测定数据、制备方法等方面阐述了锌铬催化剂、铜基催化剂、合金催化剂等国外新型金属催化剂的研究进展。     

联醇催化剂和合成甲醇催化剂的研制

介绍了LC210型联醇催化剂和LC308型合成甲醇催化剂的特点和性能,分析了工艺条件对催化剂性能的影响,对技术经济指标和经济效益进行了总结。     

Platinum-macrocycle co-catalysts for the electrochemical oxidation of methanol

Metal phthalocyanines (Fe, Co, Ni and Sn) and ruthenium tetramethylcyclam 14 and 15 were studied as cocatalysts for methanol oxidation on platinum supported catalysts. The formation of well defined monolayers of the adsorbed complexes was inferred from the Langmuirian form of the adsorption isotherms in solutions of macrocycles. The coverage at monolayer levels was low, e.g. 1.25 to 2.25×10¹³ molecules cm⁻² or 400 to 800 Ų molecule⁻¹. Enhancement for the methanol oxidation reaction was observed for Pt co-catalyzed with Sn phthalocyanine and Ru tetramethylcyclam. Ru tetramethylcyclam showed an enhancement for methanol oxidation on a per unit weight basis over pure Pt, approaching the activity of PtRu at lower potentials. Increasing the size of the nitrogen ring from 14 to 15 resulted in a lower redox potential and increase in the activity of methanol oxidation. The activity of Pt co-catalyzed with Ru TMC 15 decreased with time suggesting that the macrocycle was desorbing from the supported catalyst surface.     

Performance of ternary PtRuRh/C electrocatalyst with varying Pt:Ru:Rh ratio for methanol electro-oxidation

Highly dispersed ternary PtRuRh/C anode catalysts for direct methanol fuel cells were prepared with various contents and their electro-catalytic activities towards methanol oxidation at 25 °C and 60 °C were examined to investigate the influence of the catalyst composition. Electrocatalysts were prepared by a co-impregnation method using ethanolic solutions of metal precursors and carbon black followed by pyrolysis under reducing conditions. X-ray diffraction analysis revealed that the fcc peaks shifted to higher diffraction angles with increasing Rh content, indicating the alloying of Rh into the fcc structure. In terms of the mass specific current density, the activity towards methanol oxidation differed significantly depending on the catalysts composition and cell temperature. The catalyst prepared at a ratio of Pt:Ru:Rh = 1:1:2 exhibited the highest activity at 60 °C of 155 A (g-Pt)⁻¹ at 0.5 V vs. RHE.     

Binary and ternary anode catalyst formulations including the elements W, Sn and Mo for PEMFCs operated on methanol or reformate gas

In an exploratory approach to find improved electrocatalyst formulations binary and ternary carbon supported catalysts with the elements Pt and Ru, W, Mo or Sn, respectively, amending the choice of Pt and Pt/Ru catalysts by addition of non-Pt metal cocatalysts were manufactured by impregnation and a colloid method and tested towards their activity for anodic oxidation of H₂ containing 150 ppm CO and of methanol. Membrane-electrode-assemblies with noble metal loadings of 0.4 mg cm⁻² were manufactured and tested in fuel cell operation at 75°C with H₂ fuel contaminated by CO and at 95°C for operation on methanol. Cocatalytic activities were found for the elements W and Mo for oxidation of H₂/CO and methanol while in the case of Sn a cocatalytic activity was only found for H₂/CO-oxidation. Both for oxidation of methanol and H₂/CO the system Pt/Ru/W was superior to the other systems tested. The colloid method was found to be highly suitable for synthesizing polymetallic PEM catalysts.     

等温冷管型低压甲醇塔与双系统串联流程的应用

论述了国内外低压甲醇合成技术现状,介绍了新型等温冷管型低压甲醇塔在双合成系统串联流程的应用实例,对工艺过程、改造前后系统物料平衡进行了分析对比,提出了改造措施和设计方案。     

Improvement of fuel economy of a direct-injection spark-ignition methanol engine under light loads

The effects of ignition system, compression ratio, and methanol injector configuration on the brake thermal efficiency (BTE) and combustion of a high-compression direct-injection spark-ignition methanol engine under light loads were investigated experimentally, and its BTE was compared with its diesel counterpart. The experimental results showed that these factors significantly affect the fuel economy under light load. The BTE of a methanol engine using a high-energy multi-spark-ignition system is on average 25% higher than that of one using a single-spark-ignition system at a brake mean effective pressures (BMEP) of 0.11-0.29 MPa and an engine speed of 1600 rpm. Decreasing the compression ratio of the methanol engine from 16:1 to 14:1 markedly increases the BTE under low loads and decreases the BTE at high loads. For the methanol engine, using an injector of a 10-hole × 0.30 mm nozzle decreases the ignition delay and improves the fuel economy compared to when an injector of a 7-hole × 0.45 mm nozzle is used. The combustion duration using an injector of a 7-hole × 0.45 mm nozzle is much longer than that with one of a 10-hole × 0.30 mm nozzle under light loads. As a result, the BTE for a methanol engine with optimal parameters is improved by 27% compared to that for a methanol engine without optimized parameters at a BMEP of 0.17 MPa and an engine speed of 1600 rpm, but the BTE of the optimized methanol engine is 20% lower than that of its diesel counterpart under these operating conditions.     

Oxidation stability of biodiesel fuel as prepared by supercritical methanol

A non-catalytic supercritical methanol method is an attractive process to convert various oils/fats efficiently into biodiesel. To evaluate oxidation stability of biodiesel, biodiesel produced by alkali-catalyzed method was exposed to supercritical methanol at several temperatures for 30 min. As a result, it was found that the tocopherol in biodiesel is not stable at a temperature higher than 300 °C. After the supercritical methanol treatment, hydroperoxides were greatly reduced for biodiesel with initially high in peroxide value, while the tocopherol slightly decreased in its content. As a result, the biodiesel prepared by the supercritical methanol method was enhanced for oxidation stability when compared with that prepared by alkali-catalyzed method from waste oil. Therefore, supercritical methanol method is useful especially for oils/fats having higher peroxide values.