甲醇合成工艺进展

介绍了国内外甲醇合成工艺进展,对甲醇的气相合成工艺与液相合成工艺作了对比,指出液相合成工艺是甲醇生产未来发展的方向。认为国内外在液相甲醇合成工艺的基础研究和应用基础研究方面已做了比较充分的前期工作,利用这些研究成果,在工业上开发新的甲醇合成工艺路线是完全可能和十分必要的     

甲醇合成路线的新进展

近些年来，国内外对甲醇合成路线的改进及新合成路线的开拓取得很大进展。本文从合成气的生产方法、气相合成、液相合成及甲烷直接转化法等几方面综述了国外最新动态。     

Chemical equilibria in methanol synthesis

The chemical equilibria of the methanol reaction and the water—gas shift reaction, starting from carbon monoxide, carbon dioxide and hydrogen, were studied in a fixed-bed catalytic reactor at P = 10–80 bar and T = 200–270°C. It was found that the chemical equilibria could be described very well by thermochemical data based on ideal gas behaviour in combination with a correction for the non-ideality of the gas mixture as predicted by the Soave—Redlich—Kwong equation of state. This correction for non-ideality results in significantly better agreement with experimental data than a correction based on the original Redlich—Kwong equation of state, the Peng—Robinson equation of state, the virial equation truncated after the second virial coefficient, Lewis and Randall's rule, or not correcting at all for non-ideality, thus assuming ideal gas behaviour.     

大型甲醇合成反应器的制造

从材料的选择、简体和封头制造、大型管板加工、部件组对、主要焊缝焊接工艺以及热处理等方面论述了200kt／a甲醇合成反应器制造的控制点，以确保其成功制造，为今后同类设备的制造提供借鉴与参考。     

甲醇合成技术进展

主要介绍了目前世界上几种先进的大型甲醇合成工艺,对工艺中的核心设备——合成塔的结构做了说明,对大型甲醇合成工艺的特点进行了论述,并对几种工艺特点做了详细比较,同时介绍了液相甲醇合成技术,并预测了未来甲醇工艺的发展趋势.     

低温甲醇合成研究进展

日本学者Tsubaki等开创了一种全新的低温甲醇合成反应路径。该路径以含有二氧化碳的合成气为反应原料,使用单一低碳醇(包括甲醇)同时作为催化剂和溶剂,实现了反应原料一氧化碳在低温(443 K)条件下,一步转化率达到70%～100%。原位红外和多种表征手段证明,该反应能够在低温条件下进行,是由于催化剂上吸附的甲酸盐物种可以和多种低碳醇溶剂在低温条件发生酯化反应,生成相对应的甲酸酯。而生成的甲酸酯很容易在低温条件下,铜基催化剂表面,发生加氢反应,生成甲醇和相应的溶剂醇。该种全新的甲醇合成路径克服了常规甲醇合成过程中,甲酸盐必须在高温条件下才能发生加氢反应的关键步骤。同时,还介绍了适用于低温甲醇合成反应的金属Cu/ZnO催化剂制备方法的研究进展。全新的溶胶-凝胶-燃烧法、固相研磨-燃烧法以及甲酸辅助燃烧法直接制备高活性、纳米尺度、高分散的金属Cu/ZnO催化剂,而不需要额外的还原流程。     

MegaMax 700型甲醇合成催化剂在大型甲醇装置中的还原

介绍了MegaMax 700型甲醇合成催化剂在新型MegaMethanol大型甲醇反应器中的装填和还原情况,阐述了催化剂的还原过程和还原控制要点。     

影响甲醇合成催化剂时空收率的因素

研究温度、压力、空速、原料气组成等对甲醇合成催化剂时空收率的影响 ,以及催化剂使用前后的时空收率 ,CO、 CO2 转化率 ,粗甲醇含水量 ,粗甲醇中杂质的变化规律。并对实验结果进行了数学关联和综合分析     

煤制甲醇合成回路技改

简述煤制甲醇合成回路工艺原理和工艺流程,分析原回路不能达到设计指标,而无法满足气化炉满负荷状态运行的原因,提出改造方案。改造后,运行效果良好,达到了预期目标。     

RK-05型甲醇合成催化剂的应用情况

简要介绍RK-05型甲醇合成催化剂的物理化学性能、装填、升温还原及生产运行情况,并介绍其与一期甲醇系统运行情况相比,具有系统压力低、新鲜气耗低、反应副产物少等特点。但也存在合成塔压差大的问题。     

甲醇合成铜基催化剂的研究概述

介绍了甲醇合成催化剂的分类,对常用铜基催化剂从催化机理、助剂作用及其失活原因等方面进行了综述,讨论了各种催化剂的优缺点。     

合成气催化合成甲醇Cu基催化剂的研究

介绍了合成气催化合成甲醇Cu基催化剂的制备方法——沉淀法,并指出在制备过程中为避免催化剂失活应注意的问题。介绍了3种Cu基催化剂的活性中心模型,分别为：Cu0,Cu＋及Cu0-Cu＋模型。详细介绍了催化剂合成甲醇的反应机理：CO机理,CO2机理和CO与CO2混合反应机理。最后对甲醇合成催化剂制备提出了改进意见。     

XNC-98甲醇合成催化剂使用总结

我公司甲醇生产系统采用煤制气低压甲醇合成工艺，合成塔为鲁奇塔，塔径2200mm，塔高10523mm，内部列管高度为6000mm，共1855根，列管内径34mm，总换热面积1302m^2。装置设计生产能力为30kt／d，投产1a便突破设计生产能力。为进一步提高装置的生产能力，公司经     

液相法甲醇合成的平衡收率

对液相法甲醇合成系统进行了热力学分析，建立了求解该系统相平衡和化学平衡问题的非线性方程组。在此基础上，分别对以四甘醇二甲醚和角鲨烷为液相介质的反应热力学平衡进行了计算，结果表明液相介质具有提高甲醇平衡收率的作用。研究了液相介质的性能、用量、温度、压力及原料气组成对甲醇平衡收率的影响。     

Optimal temperature profile in methanol synthesis reactor

An optimal temperature profile is determined for a methanol synthesis reactor of LURGI type. The temperature profile is estimated so that methanol production rate in the reactor outlet will be maximized. First, the reactor is simulated based on heterogeneous one- and two-dimensional models. The comparison of the simulation results and plant data shows that the heterogeneous one-dimensional model can reliably be used for determining optimal temperature profile. Since optimal temperature profile for reversible exothermic reaction in tubular reactors is a decreasing function of reactor length, the technique of control variable parameterization is used for determining optimal temperature profile in a methanol reactor. In this way, a third order polynomial is considered for the temperature profile and the polynomial coefficients are as decision variables. The optimization is based on a Quasi-Newton's method (BFS technique), and the objective function is methanol flow rate at the reactor outlet. The results of optimization indicate that if optimal temperature profile is implemented in the reactor, methanol production will significantly be increased.     

甲醇合成路线及其进展

介绍了甲醇合成的各种路线及其最新进展。合成气合成甲醇是现行的主要工艺路线 ,而甲烷氧化法、二氧化碳加氢法是甲醇合成路线的研究热点。     

Catalytic methanol synthesis via black liquor gasification

Biofuel production from gasified black liquor is an interesting route to decrease green house gas emissions. The only pressurised black liquor gasifier currently in pilot operation is located in Sweden. In this work, synthesis gas was taken online directly from this gasifier, purified from hydrocarbons and sulphur compounds and for the first time catalytically converted to methanol in a bench scale equipment. Methanol was successfully synthesised during 45 h in total and the space time yield of methanol produced at 25 bar pressure was 0.16-0.19 g methanol/(g catalyst h). The spent catalyst exposed to gas from the gasifier was slightly enriched in calcium and sodium at the inlet of the reactor and in boron and nickel at the outlet of the reactor. Calcium, sodium and boron likely stem from black liquor whereas nickel probably originates from the stainless steel in the equipment. A slight deactivation, reduced surface area and mesoporosity of the catalyst exposed to gas from the gasifier were observed but it was not possible to reveal the origin of the deactivation. In addition to water, the produced methanol contained traces of hydrocarbons up to C₄, ethanol and dimethyl ether.     

Application of methanol synthesis reactor to large-scale plants

The developing status of world large-scale methanol production technology is analyzed and Linda's JW low-pressure methanol synthesis reactor with uniform temperature is described. JW serial reactors have been successfully introduced in and applied in Harbin Gasification Plant and the productivity has been increased by 50% and now nine sets of equipments are successfully running in Harbin Gasification Plant,Jiangsu Xinya, Shandong Kenli,Henan Zhongyuan, Handan Xinyangguang,' Shanxi Weihua and Inner Mongolia Tianye. Now it has manufacturing the reactors of 300,000 t/a for Liaoning Dahua. Some solutions for the structure problems of 1000 ～5000 t/d methanol synthesis rectors are put forward.     

Dynamic modeling of the methanol synthesis fixed-bed reactor

A dynamic model for a fixed-bed reactor for methanol synthesis is presented. The model is compared with its steady state version. The analysis points out that the numerical stability of the dynamic model is improved by opportunely increasing the level of detail. It is appropriate to introduce the diffusion terms, to work with mass fractions, to select good discretization methods for each term of the model equations. Since these aspects are usually neglected in steady state analysis, this paper investigates step-by-step their implementation, emphasizing their importance (I) in the transformation of an original hyperbolic PDE system into a parabolic PDE system; (II) in removing non-physical oscillations generated by first-order systems that may lead to relevant model prediction errors; and (III) in the approximation of the convection terms using the forward formulation, which is more stable and provides more realistic solutions.     

Liquid-phase synthesis of methanol using industrial copper-zinc catalyst

The industrial copper-zinc catalyst MEGAMAX®-phase synthesis of methanol was tested under the conditions of a liquid-phase process while varying the pressure (0.5–7.0 MPa) and the gas mixture flow rate (40–400 mL_N/min). The catalyst was shown to have high activity and selectivity in the synthesis of methanol. The best result (730 g(methanol)/kg(cat) h^?1 and selectivity 99.2%) was obtained under reaction conditions of 2.0 MPa, 240°C, H₂: CO: CO₂: N₂ = 70.5: 17.9: 6.5: 5.1, and reaction time 3 h. The concentration of methane by-product increased at gas mixture pressures over 3.0 MPa, lowering the selectivity of the process with respect to methanol. Trace amounts of ethane and water were found in addition to methane. Dimethyl ether, a typical by-product of methanol synthesis, was missing from the vapor-gas mixture over the range of pressures. The results from this study indicate that the MEGAMAX® can be used in the liquid-phase synthesis of methanol.