Synthesis of Ionic Ultramicroporous Polymers for Selective Separation of Acetylene from Ethylene

The design of highly stable and efficient porous materials is essential for developing breakthrough hydrocarbon separation methods based on physisorption to replace currently used energy-intensive distillation/absorption technologies. Efforts to develop advanced porous materials such as zeolites, coordination frameworks, and organic polymers have met with limited success. Here, a new class of ionic ultramicroporous polymers (IUPs) with high-density inorganic anions and narrowly distributed ultramicroporosity is reported, which are synthesized by a facile free-radical polymerization using branched and amphiphilic ionic compounds as reactive monomers. A covalent and ionic dual-crosslinking strategy is proposed to manipulate the pore structure of amorphous polymers at the ultramicroporous scale. The IUPs exhibit exceptional selectivity (286.1–474.4) for separating acetylene from ethylene along with high thermal and water stability, collaboratively demonstrated by gas adsorption isotherms and experimental breakthrough curves. Modeling studies unveil the specific binding sites for acetylene capture as well as the interconnected ultramicroporosity for size sieving. The porosity-engineering protocol used in this work can also be extended to the design of other ultramicroporous materials for the challenging separation of other key gas constituents.     

Selective hydrogenation of acetylene over Pd/CeO2

Five hundred ppm Pd/CeO₂ catalyst was prepared and evaluated in selective hydrogenation of acetylene in large excess of ethylene since ceria has been recently found to be a reasonable stand-alone catalyst for this reaction. Pd/CeO₂ catalyst could be activated in situ by the feed gas during reactions and the catalyst without reduction showed much better ethylene selectivity than the reduced one in the high temperature range due to the formation of oxygen vacancies by reduction. Excellent ethylene selectivity of ~100% was obtained in the whole reaction temperature range of 50°C–200°C for samples calcined at temperatures of 600°C and 800°C. This could be ascribed to the formation of Pd_xCe_1−xO_2−y or Pd-O-Ce surface species based on the X-ray diffraction and X-ray photoelectron spectroscopy results, indicating the strong interaction between palladium and ceria.     

High nitrogen carbon material with rich defects as a highly efficient metal-free catalyst for excellent catalytic performance of acetylene hydrochlorination

In this work,we developed a simple strategy to synthesize a carbon material with high nitrogen and rich carbon defects.Our approach polymerized diaminopyridine(DAP) and ammonium persulfate(APS).Following a range of different temperature pyrolysis approaches,the resulting rough surface was shown to exhibit edge defects due to N-doping on graphite carbon.A series of catalysts were evaluated using a variety of characterization techniques and tested for catalytic performance.The catalytic performance of the N-doped carbon material enhanced alongside an increment in carbon defects.The NC-800 catalyst exhibited outstanding catalytic activity and stability in acetylene hydrochlorination(C_2 H_2 GHSV=30 h~(-1),at 220℃,the acetylene conversion rate was 98%),with its stability reaching up to 450 h.Due to NC-800 having a nitrogen content of up to 13.46%,it had the largest specific surface area and a high defect amount,as well as strong C_2 H_2 and HCl adsorption.NC-800 has excellent catalytic activity and stability to reflect its unlimited potential as a carbon material.     

碳纳米管表面基团对Bi基催化剂在乙炔氢氯化反应中催化性能的影响

以多壁碳纳米管(MWCNTs)、羟基碳纳米管(MWCNTs-OH)、羧基碳纳米管(MWCNTsCOOH)为催化剂载体,采用等体积浸渍法制备负载型Bi基催化剂,在固定床反应器中评价催化剂在乙炔氢氯化反应中的性能。结果表明,以MWCNTs-OH为载体的Bi基催化剂催化性能最优,乙炔转化率最高52%。BET、FT-IR、XRD、XPS、EDS、TG、TEM和H_2-TPR表征表明,碳纳米管表面基团,尤其是羟基,可以提高活性组分的分散度、抑制催化剂表面积炭生成和减少Bi物种流失。     

乙炔发生發发气能力不足的原因及对策

分析了乙炔发生器发气能力低的原因,对发生器温度、发生器压力及发生器耙齿等方面进行了改进,提高了发气量。     

煤制乙炔关键中间体BaC2合成的热力学分析

煤制电石(CaC₂)乙炔工艺在我国煤化工行业中占有重要地位。但其关键中间体CaC₂的工业生产过程具有反应温度高、能耗大、CO₂排放严重等问题,严重制约了电石及下游相关产业的发展。开发绿色环保的煤制电石替代工艺具有重要意义。本研究提出采用BaC₂替代CaC₂作为煤制乙炔工艺的关键中间体,从热力学角度分析了BaC₂合成反应体系的特点,并在1550℃进行了合成BaC₂的实验验证。结果表明,以BaC₂替代CaC₂为煤制乙炔的关键中间体、通过BaCO₃-BaC₂-Ba(OH)₂-BaCO₃的钡循环将碳和二氧化碳转化为乙炔和一氧化碳的新路线,具有反应温度低、零CO₂排放、联产CO、固废排放少等优点,可以为现代煤化工的绿色发展提供新的思路。     

姜钟法聚氯乙烯工艺介绍及前景分析简

摘要：介绍了聚氯乙烯的性质及传统生产方法以及德州实华化工有限公司研发的聚氯乙烯生产新工艺和发展前景。     

天然气制乙炔装置炭黑循环冷却水工艺研究

介绍了天然气制乙炔装置现场循环冷却水系统工艺流程,分析了该工艺存在的环保、运行等问题,提出了技术改造的方向。通过流程改造和优化,提高了天然气制乙炔装置的环境友好性,延长装置的运行时间。     

乙炔发生器溢流管的改造

对乙炔发生器溢流管进行了改造,降低了乙炔发生器压力和电石消耗,优化了操作条件,使乙炔收率由86.81%提高至88.53%,可节约电石成本1 083.6万元/a,经济效益显著。