甲醇制烯烃分离技术进展及评述

根据甲醇制烯烃产物分布特点,提出了分离流程设计原则和目标,介绍了典型的甲醇制烯烃反应产物分离技术和DME脱除方法,并对流程特点进行了评述。

半夏、醇制半夏和清半夏的刺激性毒性及液相指纹图谱研究

目的比较半夏、醇制半夏和清半夏的刺激性毒性和三者的液相指纹图谱,考察半夏醇制方法的合理性。方法通过比较半夏、醇制半夏和清半夏对家兔眼结膜的刺激性和对大鼠腹腔渗出液中PGE2含有量的影响,考察醇制对半夏刺激性毒性的影响。Megres C18色谱柱(250 mm×4.6 mm,5μm),乙腈-0.1%甲酸水溶液梯度洗脱,检测波长为254 nm,体积流量0.6 mL/min,柱温30℃,鸟苷为对照峰,建立并比较3种半夏的HPLC指纹图谱,考察醇制对半夏化学成分的影响。结果醇制半夏能够降低对家兔眼结膜的刺激性,使大鼠腹腔渗出液PGE2量降低,该作用与清半夏相当。半夏醇制后指纹图谱变化不大,而清半夏特征指纹峰数目及峰面积显著降低。结论醇制能够达到降低半夏刺激性毒性的作用,且对半夏中核苷等水溶性成分无显著影响,醇制法可作为半夏减毒存效新方法的研究方向。

半夏醇制减毒新方法研究(Ⅰ)——新方法及新工艺研究探讨

目的:探索半夏醇制减毒新方法和最佳工艺参数。方法:以乙醇润制半夏减毒,采用正交试验设计考察乙醇量、润制时间、乙醇浓度、润制温度4个影响因素,以总游离有机酸含量为化学指标,以大鼠腹腔渗出液中PGE2含量为毒理指标,综合评分,以家兔眼结膜刺激性试验得分作为减毒的直观验证,优选半夏醇制减毒的最佳工艺,并以药效验证考察醇制工艺的合理性。结果:半夏最佳醇制工艺为生半夏在60℃,用0.5倍量的75%乙醇润制4 d,干燥后即得。半夏醇制后保留了半夏的镇咳、祛痰、抗炎作用。结论:该方法简单、可行,可作为半夏减毒存效新方法的研究方向。

煤制醇变换装置低温工艺冷凝液氨氮含量高的原因

煤制甲醇、乙二醇工艺生产过程中,变换装置存在低温工艺冷凝液氨氮含量偏高的问题。在装置正产运行的状况下,此股低温冷凝液不能得到有效处理,给生产装置带来了新的环保问题。经过专题研究、现场取样分析及物料衡算,最终找到该股冷凝液氨氮含量高的原因。

煤化工企业煤制甲醇联产醋酸中工艺技术分析

本文对煤化工企业煤制甲醇联产醋酸的核心技术进行了叙述和深入分析,并对比国内外相关工艺的发展进行了对比。本文提到的核心技术有气化、净化工艺,目标产物的合成及一氧化碳的分离等,为相关产业提供较为准确的技术选择方案。

WSA尾气制酸工艺在褐煤制醇系统中的应用

0前言 云南解化清洁能源开发有限公司解化化工分公司二甲醚厂（以下简称二甲醚厂）以小龙潭褐煤为原料，采用拥有自主知识产权的碎煤加压气化技术，“两步法”生产二甲醚，粗甲醇、二甲醚年产量分别达200kt和150kt。净化技术采用低温甲醇洗工艺，浓缩后的酸性废气采用托普索公司的WSA湿法硫酸技术处理。

降低精甲醇中乙醇含量的工艺研究

分析了煤制甲醇生产过程中产生乙醇的原因,探讨了影响精甲醇中乙醇含量的因素,通过优化“三塔精馏”工艺参数和调整侧线采出,使精甲醇中乙醇质量分数≤100 mg/kg的技术指标要求。

Synthesis and characterization of an unusual snowflake-shaped ZSM-5 zeolite with high catalytic performance in the methanol to olefin reaction

The ZSM-5 zeolite with an unusual snowflake-shaped morphology was hydrothermally synthesized for the first time,and compared with common ellipsoidal and boat-like shaped samples.These samples were characterized by N2 adsorption-desorption,X-ray fluorescence spectroscopy,scanning electron microscopy,X-ray diffraction,magic angle spinning nuclear magnetic resonance,temperature-programmed desorption of ammonia,and infrared spectroscopy of pyridine adsorption.The results suggest that the BET surface area and SiO2/Al2O3 ratio of these samples are similar,while the snowflake-shaped ZSM-5 zeolite possesses more of the（101） face,and distortion,dislocation,and asymmetry in the framework,resulting in a larger number of acid sites than the conventional samples.Catalysts for the methanol to olefin（MTO） reaction were prepared by loading Ca on the samples.The snowflake-shaped Ca/ZSM-5 zeolite exhibited excellent selectivity for total light olefin（72%） and propene（39%） in MTO.The catalytic performance influenced by the morphology can be mainly attributed to the snowflake-shaped ZSM-5 zeolite possessing distortion,dislocation,and asymmetry in the framework,and lower diffusion limitation than the conventional samples.

醇溶色素对制糖脱钙树脂的再生促进机制研究

树脂的绿色再生是离子交换技术应用于制糖工业的关键。本文研究了醇溶制糖色素存在条件下传统氯化钠再生剂对糖汁脱钙树脂的再生,探讨醇溶制糖色素对钙型树脂再生的影响,以及钙的解吸性质及动力学。结果表明,醇溶色素的存在,促进了传统氯化钠再生剂对糖汁脱钙树脂的复苏,可能的原因是醇溶酚类色素与钙盐的螯合作用促进了树脂的再生;使用动边界模型描述了钙型树脂的解吸过程,发现解吸过程的速度控制步骤为颗粒扩散,表观活化能Ea为36.90 k J/mol,反应级数为1.14,表观频率因子k0为1679 min-1,解吸过程可用假二级动力学模型描述(R2>0.99);钙型树脂的解吸过程与Freundlich等温模型拟合性良好,说明钙型树脂的解吸属于表面不均一性单分子层或多分子层扩散。研究为减少再生剂氯化钠的使用,实现糖用树脂绿色再生提供思路。

庚烯羰化制醇的原位红外光谱表征

庚烯羰化制醇的原位红外光谱表征１）焦凤英胡庆云陈艳晶（济南大学实验中心济南２５０００２）牛建中殷元骐（中国科学院兰州化学物理研究所羰基合成与选择氧化国家重点实验室兰州７３００００关键词庚烯均相催化氢甲酰化原位红外光谱铑膦催化剂铑催化剂（以较强碱性的三...

Conversion of Bio-syngas to Liquid Hydrocarbon over CuCoMn-Zeolite Bifunctional Catalysts

A series of bifunctional catalysts composed of a component for higher alcohol synthesis （Cu-CoMn oxides, CCM） and an acidic zeolite （SAPO-34, ZSM-5, Y, MCM-41） were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage pro-cess. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5〉CCM-SAPO-34〉CCM-Y〉CCM-MCM-41. CCM-ZSM-5 （20wt%, Si/Al=100） prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion （76%） and yield of liquid products （30%）. The catalysts were characterized by N2 adsorption/desorption, NH3-TPD, XRD, and H2-TPR analysis. The results showed that higher speci c surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites into CuCoMn precursors. Medium pore dimension and moderate acidity in CCM-ZSM-5 were observed, which proba-bly resulted in its excellent reaction performance. Additionally, a higher number of weaker acid sites （weak and/or medium acid sites） were formed by increasing ZSM-5 content in CCM-ZSM-5 or decreasing Si/Al ratio in ZSM-5. It was also seen that metal dispersion was higher and reducibility of metal ions was easier on the CCM-ZSM-5 catalyst prepared by coprecipitation. The higher alcohols-to-hydrocarbon process provides a promising route to hydrocarbon fuels via higher alcohols from syngas or biobased feedstocks.

Changing the balance of the MTO reaction dual-cycle mechanism: Reactions over ZSM-5 with varying contact times

The methanol to olefins （MTO） reaction was performed over ZSM‐5 zeolite at 300℃ under various methanol weight hourly space velocity （WHSV） values. During these trials, the catalytic perfor‐mance was assessed, in addition to the formation and function of organic compounds retained in the zeolite. Analysis of reaction effluents and confined organics demonstrated a dual‐cycle reaction mechanism when employing ZSM‐5. The extent of the hydrogen transfer reaction, a secondary reac‐tion in the MTO process, varied as the catalyst‐methanol contact time was changed. In addition, 12C/13C‐methanol switch experiments indicated a relationship between the dual‐cycle mechanism and the extent of the hydrogen transfer reaction. Reactions employing a low methanol WHSV in conjunction with a long contact time favored the hydrogen transfer reaction to give alkene products and promoted the generation and accumulation of retained organic species, such as aromatics and methylcyclopentadienes, which enhance the aromatic cycle. When using higher WHSV values, the reduced contact times lessened the extent of the hydrogen transfer reaction and limited the genera‐tion of methylcyclopentadienes and aromatic species. This suppressed the aromatic cycle, such that the alkene cycle became the dominant route during the MTO reaction.

Charge compensation dominates the distribution of silica in SAPO-34

The distribution of Si atoms in the SAPO-34 framework determines its acidity and catalytic effects.This was investigated using the charge balance between the inorganic framework and trapped template ions.Three types of templates,which yielded R~＋,2R~＋ and 2R^（2＋） positive charges in the cages of SAPO-34,were obtained from single crystal data and they were used to direct the synthesis of SAPO-34 with different Si contents and formation of isolated Si atoms and Si islands in the lattice.The concentration limits of SiO2 in the gel for constituting isolated Si atoms were calculated and verified experimentally.Si islands,including 5-Si,8-Si,11-Si,14-Si island were described on the basis of host-guest charge compensation.An overall view of the distribution of Si atoms in SAPO-34 was given and a criterion for the strength and density of acid sites in SAPO-34 for it to be an efficient catalyst for MTO was made available.

Biohydrogen production with anaerobic sludge immobilized by granular activated carbon in a continuous stirred-tank

A continuous stirred-tank reactor （CSTR） process with granular activated carbon （GAC） was developed for fermentation hydrogen production from molasses-containing wastewater by mixed microbial cultures. Operation at 35℃, an initial biomass of 17.74 g·L^-1 and hydraulic retention time （HRT） of 6 h, the CSTR reactor presented a continuous hydrogen production ability of 5.9 L·d^-1 and the biogas was free of methane throughout the experiment. Dissolved fermehtation products were predominated by ethanol and acetate acid, with smaller quantities of propionic acid, butyric acid and valeric acid. It was found that GAC could make the immobilized system durable and stable in response to organic load impacting and low pH value. When the organic loading rate （OLR） ranged from 8 kgCOD/（m^3d） to 4 kgCOD/（m^3d）, stable ethanol-type fermentation was formed, and the ethanol and acetate concentrations account for 89% of the total liquid products.

Enhanced MTO performance over acid treated hierarchical SAPO-34

Hierarchical SAPO‐34 crystals were synthesized by a facile acid etching post‐treatment. Butterfly‐shaped porous patterns on four side faces and hierarchical pores composed of micropores,mesopores and macropores were formed after a nitric acid or oxalic acid treatment. The catalyticperformance of the hierarchical SAPO‐34 for the methanol to olefins (MTO) process showed that thesynergistic effect of the hierarchical pores and acid sites resulted in a longer catalyst lifetime (from210 to 390 min for the acid treated SAPO‐34) and higher selectivity to light olefins of 92%–94%.The ethylene selectivity can be adjusted between 37.4% and 51.5% by the pore size. No hierarchical SAPO‐34 was obtained after a treatment with butanedioic acid, and with this sample, fast deactivation was detected after 100 min.

Methanol-to-propylene process: Perspective of the most important catalysts and their behavior

The methanol-to-propylene （MTP） process is a route of methanol conversion to hydrocarbons, which is in high demand because of limited oil resources. The present paper discusses the effect of catalyst structure on the MTP process conditions, and the role of different zeolite factors, such as acidity, crystal size, mesoporosity, and topology, on the activity and selectivity of the MTP reaction.

In situ Synthesis of SAPO-34 Zeolites in Kaolin Microspheres for a Fluidized Methanol or Dimethyl Ether to Olefins Process

SAPO-34 zeolite is considered to be an effective catalyst for methanol or dimethyl ether conversion to olefins. In this study,we developed the in situ synthesis technology to prepare SAPO-34 zeolite in kaolin micro-spheres as a catalyst for fluidized methanol or dimethyl ether to olefins process. The silicoaluminophosphate zeolite was first time reported to be synthesized in kaolin microspheres. The SAPO-34 content of synthesized catalyst was about 22% as measured by three different quantitative methods(micropore area,X-ray fluorescence and energy dispersive spectroscopy element analysis) . Most of the SAPO-34 zeolites were in nanoscale size and distributed uniformly inside the spheres. The catalytic performance was evaluated in fixed bed and fluidized bed reactors. Compared with the conventional spray-dry catalyst,SAPO/kaolin catalyst showed superior catalytic activities,bet-ter olefin selectivities(up to 94%,exclusive coke) ,and very good hydrothermal stability. The in situ synthesis of SAPO-34 in kaolin microspheres is a facile and economically feasible way to prepare more effective catalyst for fluidized MTO/DTO(methanol to olefins/dimethyl ether to olefins) process.

Enhancing ethylene selectivity in MTO reaction by incorporating metal species in the cavity of SAPO-34 catalysts

The SAPO‐34 catalysts were modified with metal cations by different processes(conventional ion exchange(CIE),template‐assisted ion incorporation(TII)and alcoholic ion exchange(AIE)),systematically characterized by XRD,XRF,N2 adsorption‐desorption,UV‐VIS,H2‐TPR,EPR,SEM,EDX,XPS,NH3‐TPD,1H NMR and IGA,and applied in MTO reaction.The metal cations incorporation introduces extra diffusion hindrance by metallic species located in the cavity of SAPO‐34.In particular,the Zn cations‐modified SAPO‐34 catalysts exhibit core‐shell like structure,with Si‐rich and Zn‐rich sublayer near the external surface,which favors the coke deposition at the beginning of MTO reaction,exerts marked impact on the diffusion of the generated products with relatively large molecular size(e.g.propylene),and significantly increases the selectivity to ethylene and the ratio of ethylene to propene in the MTO reaction.