二段式吸收塔强化水洗技术提纯沼气过程

压力水洗技术已成为提纯沼气的关键技术之一。采用填料吸收塔进行CO₂脱除实验研究,考察了液气比、吸收压力、吸收温度、CO₂初始含量、填料层高度对CO₂脱除率的影响,以及液气比、沼气流量对总体积吸收系数的影响,并运用填料塔与喷雾塔结合的二段式吸收塔进行压力水洗提纯沼气的过程强化实验。实验结果表明,吸收压力和液气比的增大、吸收温度的降低、填料层高度的增加有利于CO₂的脱除,体积总吸收系数随着液气比及沼气流量的增加而增大。二段式吸收塔能够提高CO₂吸收效果,当沼气处理量为10 L·min^-1,填料层高度为100 cm,CO₂含量小于3%时,与填料塔相比二段式吸收塔可以减少约12%的吸收液用量,并且采用110 cm填料的二段式吸收塔获得最佳的提纯效果,CO₂脱除率达到97.4%。     

真空变压吸附沼气净化过程的仿真研究

真空变压吸附(VPSA)是一种气体分离技术,该技术运用在沼气净化过程还存在较多的问题,针对该过程吸附塔出口浓度出现的浓度峰问题,运用线性推动力模型(LDF)与Langmuir等温方程对其建立了数学模型,模拟分析了缓冲罐中杂质浓度对吸附步骤出口浓度的影响。结果表明:相同吸附时间下,随着吸附压的降低,二均降结束时会有更多的杂质进入缓冲罐,而缓冲罐中的杂质又会通过一均升步骤进入吸附塔,最终使得吸附步骤出口浓度曲线出现波峰,从而影响了吸附塔出口CH₄含量。通过模型的分析,吸附时间随着吸附压不断降低而缩短,可以有效控制杂质进入缓冲罐,从而使吸附塔出口CH₄含量提高。     

A review of chemical absorption of carbon dioxide for biogas upgrading

Significant attention has been given to biogas production, purification and upgrading as a renewable and clean fuel supplement. Biogas is a product of an anaerobic digestion process comprising methane, carbon dioxide, and trace amounts of other gases. Biogas purification removes trace gases in biogas for safe utilisation. Biogas upgrading produces methane-rich biogas by removing bulk carbon dioxide from the gas mixture. Several carbon dioxide removal techniques can be applied for biogas upgrading. However, chemical absorption of carbon dioxide for biogas upgrading is of special significance due to its operation at ambient or near ambient temperature and pressure, thus reducing energy consumption. This paper reviews the chemical absorption of carbon dioxide using amine scrubbing, caustic solvent scrubbing, and amino acid salt solution scrubbing. Each of these tech-niques for biogas upgrading is discussed. The paper concludes that an optimised implementation of the chemical absorption techniques for biogas upgrading requires further research.     

工业尾气变压吸附提纯一氧化碳中试

Using pressure swing adsorption （PSA） technology to purify carbon monoxide （CO） discharged from industrial gases is a high-efficiency and economical method. In this article, a four-bed PSA experiment for CO purification was improved and optimized, in which a set of 120 m^3·h^-1 pilot-scale PSA device was developed to purify CO from industrial tail gases, a set of control systems suitable for industry production was developed, and the influences of the operating parameters on CO purification were investigated. The experimental results indicated that the pilot-scale PSA device could produce qualified product gas and get high CO recovery ratio under optimized conditions. The research may provide reliable fundamental data, for industrial scale utilization of CO, from industrial tail gases, and have strong market competitive power and a broad promoted application prospect.     

黄磷尾气变温、变压吸附净化技术的新进展

由于黄磷尾气净化分离难度大,阻碍了黄磷中CO的有效利用。介绍达科特能源科技公司开发的黄磷尾气净化分离新技术。其特点是:1)用焦炭过滤除尘和脱磷泥,再用变温吸附法脱磷、硫和砷的氢化物;2)用湿式氧化法脱硫,回收单质硫;3)用真空变压吸附法脱碳。该新工艺成功应用于合成甲酸钠的工业装置。     

变压吸附装置均压压力及管径计算的探讨

本文系统地推导了变压吸附过程中均压压力和管道流速的计算公式,结合均压压力的理论计算值与实际开车数据并进行对比,引入吸附放大系数对管径计算进行修正,为变压吸附管径设计和现场开车数据定量分析提供理论基础。     

煤层气浓缩用碳分子筛的研制及性能研究

为评价分析碳分子筛(Carbon Molecular Sieves,CMS)产品性能,以酚醛树脂废料为主要原料,通过添加助剂,采用炭化/气相沉积一体化工艺,制备了专用于煤层气提浓的BM碳分子筛(记为BMCMS)。采用CO_2吸附法、加压热重法及四塔变压吸附法对BMCMS及商业碳分子筛(记为JCCMS)的孔隙结构、CH_4和N_2的吸附容量、速度以及对煤层气的实际分离性能等进行研究。结果表明,BMCMS碳分子筛的孔隙以0.85 nm以下微孔为主,主要分布在0.4~0.65 nm,其比例占整个孔隙的66%以上,高于JCCMS的65%;碳分子筛的孔隙直径为N_2分子的1.1~1.8倍时,该类孔隙适宜吸附N_2,而对CH_4的吸附具有阻碍作用;当用于PSA浓缩抽采煤层气时,可将煤层气中CH_4浓度提高25.6%,实际运行指标优于JCCMS。     

VCM精馏尾气净化回收工艺

介绍了宁夏西部聚氯乙烯有限公司采用变压吸附法回收VCM精馏尾气的新工艺,与原活性炭吸附工艺法相比,具有PLC自动化控制程度高、运行稳定、操作方便、安全性能好等优点。实际运行结果表明：采用变压吸附法工艺回收VCM精馏尾气,VCM、C2H2回收率大于99．9％,排放的尾气中VCM质量浓度小于36mg／m^3,C2H2质量浓度小于150mg／m^3。     

IDA工艺路线草甘膦生产废气中H2的回收提纯与利用

IDA工艺路线草甘膦的脱氢岗位产生的H_2尾气中含有较多的杂质,采用水洗、酸洗、除氧、干燥、变压吸附(简称PSA)等工艺进行H_2提纯,H_2含量达99.8%以上,该工艺具有H_2回收率高、品质好,而且能将尾气中的有害杂质除尽等优点。     

Equilibrium Analysis of Cyclic Adsorption Processes: CO2 Working Capacities with NaY

Abstract

The most common application of adsorption is via pressure swing adsorption. In this type of design, the feed and regeneration temperatures are kept approximately equal, whereas the feed pressure is higher than the regeneration pressure. By exploiting the difference in the amount adsorbed at a higher pressure to the amount adsorbed at a lower pressure, a working capacity is realized. Therefore, by examining the expected (ideal) working capacity of an adsorbent, a performance characteristic can be analyzed for a pressure swing adsorption process (PSA). For this work, feed pressures up to 2.0 atm CO₂ and feed temperatures from 20°C to 200°C were investigated. These limits were chosen due to the nature of the target process: CO₂ removal from flue gas.

Carbon dioxide adsorption isotherms were determined in a constant volume system at 23°C, 45°C, 65°C, 104°C, 146°C, and 198°C, for pressures between 0.001 and 2.5 atm CO₂ with NaY zeolite. These data were fit with the temperature dependent form of the Toth isotherm. Henry's Law constants and the heat of adsorption at the limit of zero coverage were also determined using the concentration pulse method. Comparison of the Henry's Law constants derived from the Toth isotherm, and those obtained with the concentration pulse method provided excellent agreement.

By using the Toth isotherm, expected working capacity contour plots were constructed for PSA (Pressure Swing Adsorption), TSA (Temperature Swing Adsorption), and PTSA (Pressure Temperature Swing Adsorption) cycles. The largest expected working capacities were obtained when the bed was operated under a high‐pressure gradient PSA cycle, or a high thermal and pressure gradient PTSA cycle. The results also showed that certain TSA and PSA cycle conditions would result with higher expected working capacities as the feed temperature increases.     

变压吸附技术净化分离有机蒸气的研究进展

从变压吸附分离回收低沸点和中高沸点有机蒸气、变压吸附用吸附剂以及变压吸附分离回收有机蒸气工艺及其过程的计算机模拟等方面,评述了变压吸附技术在净化分离有机蒸气方面的研究进展。指出今后的研究方向为:新型变压吸附用吸附剂;多种分离过程的集成技术;过程优化设计;智能型控制系统;多成分有机气体的变压吸附分离;利用计算机进行变压吸附过程模拟的基础研究;吸附和脱附的传质、传热基础理论等。     

Adsorptive cyclic purification process for CO2 mixtures captured from coal power plants

CO₂ capture technology combined with bulk separation and purification processes has become an attractive alternative to reduce capture costs. Furthermore, the required purity in the application for CO₂ conversion and utilization is more stringent than that required from a captured CO₂ mixture for geological storage. In this study, an adsorptive cyclic purification process was developed to upgrade a CO₂/N₂ mixture captured from greenhouse gas emission plants as a feasibility study for a second capture unit or captured CO₂ purifier. To purify 90% CO₂ with balance N₂ as a captured gas mixture, two‐bed pressure swing adsorption and pressure vacuum swing adsorption (PVSA) processes using activated carbon were experimentally and theoretically studied at adsorption pressures of 250–650 kPa and a fixed vacuum pressure of 50 kPa. CO₂ with higher than 95% purity was produced with more than 89% recovery. However, a four‐bed PVSA process could successfully produce CO₂ with greater than 98% purity and 90% recovery. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1051–1063, 2017     

车用沼气提纯净化工艺技术研究

概述了车用沼气提纯净化工艺技术现状,评价了目前车用沼气脱除硫化氧、二氧化碳和水的工艺技术,重点论述了生物法、活性炭和变压吸附联合脱硫化氢,氢氧化钠溶液法吸收二氧化碳工艺和冷分离法除水工艺.指出提纯净化工艺具有较为广阔的发展前景.     

碳分子筛变压吸附提纯沼气的性能

选择碳分子筛,以CH₄和CO₂为原料气,对变压吸附法提纯沼气中生物甲烷的分离性能进行了研究。采用高精度智能重量分析仪IGA-100测定了25℃下CH₄、CO₂和N₂纯组分气体在碳分子筛上的吸附平衡等温线,计算了3种气体在碳分子筛内的扩散速率CO₂>N₂>CH₄。使用单塔变压吸附装置测量了动态吸附穿透曲线,考察了吸附压力、气体流量和少量氮气等因素对吸附分离的影响,并对吸附机理做了初步探讨。实验结果表明,在吸附压力为0.4MPa、气体流量为200mL/min时,在碳分子筛上CO₂穿透吸附量为35.9mL/g,CH₄穿透吸附量为5.4mL/g,CO₂/CH₄分离系数高达12.6,可直接从吸附塔顶富集纯净的CH₄,而且碳分子筛可以通过抽真空完全再生,是一种理想的吸附材料;在有少量氮气存在的实验条件下,由于碳分子筛对CH₄和N₂具有动力学分离效应,仍能在塔顶富集高浓度的CH₄。     

吸附法产品氢纯度和收率的研究

本文探讨了中国神马集团尼龙66盐公司制氢装置的变压吸附气体分离的机理,通过试验,找出了运行方式与回收率的关系以及吸附压力、真空度、吸附时间对产品氢纯度的影响,确定了对产品氢的纯度和收率起主要作用的工艺参数,并选定了合适的操作条件,使得产品氢纯度达到了99.9%以上,产品氢的收率增至85%以上。     

变压吸附制氮机均压方式的研究

简述了变压吸附制氮装置工艺流程、工作过程和均压方式。介绍了对变压吸附制氮装置等势平衡均压、不等势平衡均压、等势不平衡均压、不等势不平衡均压方式的实验结果,着重介绍了等势不平衡均压方式的特点。     

采用新型吸附剂及变温变压吸附技术脱除氯乙烯单体中的水分

介绍了采用新型吸附剂及变温变压吸附技术脱除氯乙烯单体中水分的原理及工艺流程。该技术用于20万t/a氯乙烯单体装置的深度脱水处理后,氯乙烯单体的含水质量分数由700μg/g下降到20~50μg/g。该技术脱水能力强、效率高,生产过程中无"三废"排放。     

氮气纯化工艺技术应用进展

介绍了加氢除氧和无氢除氧纯化制取高纯氮气的几种工艺路线和应用情况,并对应用情况进行分析对比,提出无氢氮气纯化技术是发展方向.