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。     

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<正>变压吸附脱碳从变换气中脱除二氧化碳,氢收率可达99.5%,氮收率可达96%~99%,一氧化碳收率可达95%~98%,还可同时获得纯度大于98.5%(体积分数)的二氧化碳,2005年该项目被列为四川省重点科研项目。变压吸附提氢氢纯度99.9%(体积分数)时,氢收率可达95%~98%,氢纯度99.99%(体积分数)时,氢收率可达90%~95%,2002年该项目被列为四川省重点科研项目。变压吸附提纯与生产食品级或工业级二氧化碳变压吸附提纯一氧化碳变压吸附空分制氧提供XHK集散型造气微机油压控制系统,用户遍及全国各地。     

变压吸附制氮技术在石化企业中的应用

变压吸附制粗氮已成功投用于化纤生产，本文介绍了PN—5000型变压吸附制氮及NC—3000型氮气净化工艺技术，分析了变压吸附部分氮气产量、压力与纯度之间的关系，并与同规模的深冷制氮技术在操作、经济性方面进行了较全面的比较。     

变压吸附制氮机组运行总结

变压吸附空分制氮技术以洁净的压缩空气为原料,利用焦炭分子筛吸附其中的氧气成分,从而制得高纯度的氮气。介绍了变压吸附制氮机组的工作原理、影响氮气纯度的因素以及运行状况。     

变压吸附制氮技术的应用

从变压吸附制氮技术原理和沈阳化工公司变压吸附制氮生产的实际情况,分析了变压吸附制氮技术的应用及发展前景。说明了变压吸附制氮技术在化工生产中仍是较适宜的制氮方法。     

变压吸附制氮性能主要影响参数的研究

介绍了变压吸附制氮技术的优点、原理方法及工艺流程,实验研究了吸附压力、吸附解吸时间、产品流量等主要工艺参数对变压吸附制氮装置性能的影响,最后得出实验装置的最佳工艺条件为:吸附压力0.8 MPa,吸附解吸时间54 s,均压时间4 s,产品气出气流量7 m3/h。此时,实验装置制得的产品氮气体积分数最稳定,平均体积分数98%以上,回收率在40%左右。     

非耦联吸附塔新变压吸附工艺的实验研究

通过提氢实验研究一种新的变压吸附工艺.变压吸附流程的主要特征是通过中间均压罐打开吸附塔之间由均压步骤形成的耦联,从而实现了各塔操作的独立性,并提供了降低吸附压力的可能性.以H₂/N₂/CH₄（60/10/30）混合气模拟石油炼厂干气,进行低吸附压力（≤1 MPa）条件下的提氢操作.针对已有变压吸附工艺的不足和新流程特征,确定了新流程的变压吸附循环时序.分别采用普通活性炭（OAC）和高比表面活性炭（SAC）与5A沸石分子筛（ZMS-5A）的组合吸附剂,研究了不同吸附压力下的变压吸附分离效果,证明此种变压吸附新工艺在1 MPa以下、甚至0.4 MPa的低吸附压力下运行,亦可在较高的回收率下达到99.99%的高氢气纯度,并且显示出更强的对偶然性故障的应变能力.     

化肥信息

新型 PSA 制氮装置投入运行由化工部西南化工研究院开发设计的新型变压吸附(PAS)空分制氮装置于1992年10月20日在核工业西南物理研究院投入运行。该装置采用一种新的 PSA 工艺流程,使用国产5A 分子筛作吸附剂,处理空气量90标米~3/时,可根据用户要求输出不同纯度的氮气。氮气纯度和     

对分子筛变压吸附制氮最适宜条件的初步探究

本实验主要运用单因子变量法探究分子筛变压吸附制氮工艺中影响氮气纯度的因素,并最后得出该工艺的最佳工艺参数:进口温度为-5℃、吸附压力为0.7MPa、进料流量为200m3/h,此时氮气纯度最高可达99.99%。     

13X-APG沸石真空变压变温耦合工艺吸附捕集烟道气中CO2

采用13X-APG沸石吸附捕集烟道气中CO2,并研发了五步循环真空变压变温(VTSA)耦合吸附捕集工艺. 实验测定了循环吸附/解吸过程中吸附剂再生率、烟道气中CO2回收率、产品气量及产品气中CO2纯度,并与传统的真空变压吸附工艺(VSA)和变温吸附工艺(TSA)比较. 由于VTSA在真空解吸的同时加热吸附剂,减少了真空泵的电耗,可在较温和的真空下(约3′103 Pa)操作,附加的吸附剂再生温度也不高,90~150℃下吸附剂再生率达97%以上,CO2回收率达98%以上. 吸附剂捕集CO2的量可提高到1.8 mol/kg,是VSA工艺产品气量的2倍,且产品气中CO2纯度提高到90%以上.     

Moderate-pressure cryogenic air separation process

A new cryogenic air separation process has been developed which complements the traditional double column low pressure air separation cycle^1,2. The process, designated the M-Plant cycle (for moderate pressure), focuses upon high fractional recovery of argon and production of moderate pressure gaseous nitrogen. The M-Plant cycle distillation system inverts product pressures and provides crude argon and high purity nitrogen at about 200 kPa pressure with high purity oxygen slightly above atmospheric pressure. The traditional T-Plant cycle uses a standard low pressure double column distillation system which furnishes the oxygen at about 140 kPa pressure and crude argon and high purity nitrogen at slightly above atmospheric pressure. Since nitrogen and argon comprise the larger part (79%) of the processed air, the M-Plant cycle conserves product pressure energy and results in a physically smaller upper column and nitrogen piping which reduces capital cost. Customers requiring large amounts of gaseous nitrogen at about 200 kPa pressure and above can realize as much as 10% energy savings and up to 5% greater argon recovery over the traditional T-Plant.     

π型向心径向流吸附器变质量流动特性研究

对径向流吸附器内变压吸附(PSA)制氧的变质量流动规律进行研究,有助于准确掌握吸附过程及床层内的变量因素对制氧性能的影响。对π型向心径向流吸附器建立气固耦合的两相吸附模型,并对其PSA制氧过程进行了数值模拟研究,得到了床层内氧气浓度分布、温度分布以及产品气浓度的变化规律。结果表明：首次循环结束时床层内氧气最高摩尔分数可达66.02%,回收率29.2%。非稳定循环期间,氧气摩尔分数从66.02%升高至 97.5%,回收率从29.2%提高至38.5%。循环达到稳定后,床层内氧气摩尔分数最高可达98.6%,回收率38.9%左右,且达到稳定状态后床层内气固两相温差减小,逐渐达到热平衡。获得了吸附器内部气体与吸附剂两相间的传质、传热过程,为π型向心径向流吸附器用于PSA制氧提供技术支持。     

炭分子筛CH4/N2吸附分离

煤层气(CBM)是一种非常规天然气。在中国,煤层气在抽采出来时常混有空气。考虑到安全因素,氧气首先应该被去除。之后,煤层气利用的最重要步骤则是甲烷-氮气混合气体的甲烷高效提浓。本文搭建了双床变压吸附(PSA)装置,选择特定的炭分子筛(CMS)进行CH₄/N₂混合物分离实验研究。由于CMS的动力学吸附特性,氮被吸附在CMS上,带有一定压力的甲烷则连续输出。研究了吸附压力、进气速度和循环周期等因素对吸附过程整体性能的影响。从50% CH₄/50% N₂的原料气可以获得95.45%纯度的甲烷产品,而从30% CH₄/70% N₂的原料气可以获得94.89%纯度的甲烷产品。研究表明,以上3个参数都对分离性能有影响,其中后两者的影响更大。在较低吸附压力和较低进气速度时更容易获得纯度90%以上的甲烷产品。另外,循环周期越短,获得的甲烷纯度越高。     

Modelling and simulation of two-bed PSA process for separating H_2 from methane steam reforming

Methane steam reforming is the main hydrogen production method in the industry. The product of methane steam reforming contains H_2, CH_4, CO and CO_2 and is then purified by pressure swing adsorption(PSA) technology. In this study, a layered two-bed PSA process was designed theoretically to purify H_2 from methane steam reforming off gas. The effects of adsorption pressure, adsorption time and purgeto-feed ratio(P/F ratio) on process performance were investigated to design a PSA process with more than99.95% purity and 80% recovery. Since the feed composition of the PSA process changes with the upstream process, the effect of the feed composition on the process performance was discussed as well.The result showed that the increase of CH_4 concentration, which was the weakest adsorbate, would have a negative impact on product purity.     

变压吸附制氮装置用于工业生产中的惰性保护

简要介绍变压吸附制氮技术的基本原理、变压吸附制氮装置以及用于工业生产中的惰性保护     

草甘膦生产中甲醇回收工序技术改造

针对草甘膦生产中甲醇回收工序存在的产品产量低、质量不稳定、能耗高等问题,在对原有装置进行分析及模拟计算的基础上,提出了以下改造方案:①将甲缩醛塔回流比从8.0降至3.8左右;②选用新型填料和塔内件降低全塔压降。工业试验结果表明,改造后的装置生产能力扩大2.25倍,能耗大幅降低,从而在扩能的同时节约了成本。     

中间气两步充压对快速真空变压吸附制氧的影响

针对快速变压吸附制氧浓度和回收率低问题,提出了用于提高产氧浓度和回收率的中间气两步充压的快速真空变压吸附流程,并对该流程进行了研究。结果表明：在快速真空变压吸附制氧过程中,中间气先在出气端充压可以有效提高产氧浓度,之后再在进气端充压可提高氧气回收率。出气端充压前中间气压力及氧浓度和进气端充压后床层压力是影响产氧浓度和回收率提高的关键参数。当吸附和解吸压力分别为240、60 kPa时,循环氧气回收率为34.57%,且每天产单位吨氧需吸附剂量为61.18 kg·TPD^-1。     

Single bed pressure swing adsorption process to generate high purity nitrogen

The separation of air for the production of nitrogen by pressure swing adsorption over a carbon molecular sieve is kinetically based. The basic steps involved in a cycle are typically pressurization, high pressure adsorption, countercurrent blowdown and vent. Simulations studies with DAPS (Dynamic Adsorption Process Simulator) were performed to analyze the effect of the pressurization rate and bed length on the performance of a single bed nitrogen pressure swing adsorption unit in the high purity region. Both specific product and yield improve with the bed length due to the reduction in the axial dispersion effect. A comparison between the predictions of the theoretical model and experimental results was carried out.     

Carbon-based oxygen selective desiccants for use in nitrogen PSA

Techniques for the production of composite oxygen selective adsorbents are disclosed. These adsorbents are comprised of a carbon molecular sieve (CMS) which is kinetically selective for the adsorption of oxygen over nitrogen and an agent for the sorption of water such as LiCl or SiO₂. The adsorption properties of the composite adsorbents and results obtained from pressure swing adsorption (PSA) process testing are presented. The composite adsorbents improve the nitrogen PSA process performance (recovery and productivity) over the use of conventional desiccants which do not exhibit oxygen selectivity. Using a standard nitrogen PSA process cycle, replacement of conventional inorganic desiccants like alumina with the current CMS-based desiccants improved air recovery 2 to 4 percentage points and increased nitrogen productivity 15 to 20% at 70°F and a nitrogen purity of 99.5%.