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利用碳基材料具有良好的导电导热性能,研发电解吸技术,取代传统的真空解吸工艺,进行吸附剂再生。估算能耗,为碳基材料吸附捕集温室气体CO2的研究和应用提供基础依据。筛选出十余种由椰壳、煤、沥青、木炭和聚合物基体制备成的颗粒状、纤维状以及蜂窝状的碳基吸附剂,进行实验研究。基于实验结果,比较捕集烟道气中CO2的吸附量、选择性、电加热升温速率、电解吸工艺的电能耗。探讨采用碳基材料吸附和电解吸技术捕集烟道气中CO2的有效性和可行性。实验结果表明:采用电加热碳基材料吸附剂,升温速率较快,能使吸附剂达到快速解吸再生的目的。而且电直接加热到吸附剂,电能利用率较高。通过表面改性等方法提高碳基材料吸附CO2容量,电解吸工艺在CO2吸附捕集技术中具有显著的优势。 相似文献
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采用分别装载活性炭和NA型吸附剂的复合床层的变压吸附工艺来脱除合成气中微量的CO和CO2,并利用Aspen-Adsim软件对其进行模拟和优化。模拟结果表明,吹扫气量对工艺性能有较大的影响,吹扫气由处在顺放步骤的吸附塔提供,因此在顺放步骤将床层压力降至较低压力,可获得较大的吹扫气量,此时的工艺性能也较优。模拟结果还表明,均压次数对工艺性能也有影响。在相同的顺放压降下,将变压吸附过程中的3次均压变为2次均压,可减少吸附剂用量,吸附剂产率更高,但塔底尾气量要相应增加。 相似文献
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针对燃煤电厂烟道气中CO2的捕集,采用变压吸附法,从穿透时间、吸附量、分离因子、氨基利用率等方面研究了TEA(三乙醇胺)负载率对胺改性硅胶吸附分离CO2的影响,并进一步考察了胺改性吸附剂中含水量对CO2分离性能的影响。结果表明:TEA改性硅胶对CO2的选择性增强,TEA负载率越高,分离因子越大,TEA负载率为0.8时的分离因子为3.86,是无负载时1.7倍;水的存在能大幅度增强CO2的吸附,水负载率越高,分离因子越大,水负载率为0.35时的分离因子高达24.50,为无水时的7倍,且常温下吸附剂仍可完全再生并具有良好稳定性;氨基利用率随TEA负载率的增大而降低,随水负载率的增大而增大。 相似文献
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液化厂脱水工艺常用的有变温变压吸附法(PTSA)和恒压变温吸附法(TSA)两种方式,本文通过两种工艺在液化工厂中的实际运用,总结出两种工艺特点并对进行比选,确定恒压变温再生(TSA)的合理性和可靠性。 相似文献
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通过窑尾CO2变压吸附捕集与利用的成套装置,将窑尾烟气CO2提纯到40%后,巧妙搭载在飞灰水洗水泥窑协同处置技术系统中,用于飞灰水洗液硬度降控和pH调节,低成本利用窑尾烟气CO2.同时结合前期装置运行中出现的问题,进行技术优化改进,建成变温吸附(TSA)+变压吸附(PSA)的碳捕集装置一套,该装置CO2吸附速率可达到1... 相似文献
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Jianghua Ling Penny Xiao Augustine Ntiamoah Dong Xu Paul Webley Yuchun Zhai 《中国化学工程学报》2016,24(4):460-467
Different VSA(Vacuum Swing Adsorption) cycles and process schemes have been evaluated to find suitable process configurations for effectively separating CO2 from flue gases from different industrial sectors. The cycles were studied using an adsorption simulator developed in our research group, which has been successfully used to predict experimental results over several years. Commercial zeolite APGIII and granular activated carbon were used as the adsorbents. Three-bed VSA cycles with- and without-product purge and 2-stage VSA systems have been investigated. It was found that for a feed gas containing 15% CO2(representing flue gas from power plants), high CO2 purities and recoveries could be obtained using a three-bed zeolite APGIII VSA unit for one stage capture, but with more stringent conditions such as deeper vacuum pressures of 1–3 k Pa. 2-stage VSA process operated in series allowed us to use simple process steps and operate at more realistic vacuum pressures. With a vacuum pressure of 10 k Pa, final CO2 purity of 95.3% with a recovery of 98.2% were obtained at specific power consumption of 0.55 MJ·(kg CO2)-1from feed gas containing15% CO2. These numbers compare very well with those obtained from a single stage process operating at1 k Pa vacuum pressure. The feed CO2 concentration was very influential in determining the desorption pressure necessary to achieve high separation efficiency. For feed gases containing N 30% CO2, a singlestage VSA capture process operating at moderate vacuum pressure and without a product purge, can achieve very high product purities and recoveries. 相似文献
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Reza Haghpanah Ricky Nilam Arvind Rajendran Shamsuzzaman Farooq Iftekhar A. Karimi 《American Institute of Chemical Engineers》2013,59(12):4735-4748
A systematic analysis of several vacuum swing adsorption (VSA) cycles with Zeochem zeolite 13X as the adsorbent to capture CO2 from dry, flue gas containing 15% CO2 in N2 is reported. Full optimization of the analyzed VSA cycles using genetic algorithm has been performed to obtain purity‐recovery and energy‐productivity Pareto fronts. These cycles are assessed for their ability to produce high‐purity CO2 at high recovery. Configurations satisfying 90% purity‐recovery constraints are ranked according to their energy‐productivity Pareto fronts. It is shown that a 4‐step VSA cycle with light product pressurization gives the minimum energy penalty of 131 kWh/tonne CO2 captured at a productivity of 0.57 mol CO2/m3 adsorbent/s. The minimum energy consumption required to achieve 95 and 97% purities, both at 90% recoveries, are 154 and 186 kWh/tonne CO2 captured, respectively. For the proposed cycle, it is shown that significant increase in productivity can be achieved with a marginal increase in energy consumption. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4735–4748, 2013 相似文献
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Gongkui Xiao Penny Xiao Andrew Hoadley Paul Webley 《Frontiers of Chemical Science and Engineering》2021,15(3):483
This study explored the feasibility of integrating an adsorption and solvent scrubbing process for post-combustion CO2 capture from a coal-fired power plant. This integrated process has two stages: the first is a vacuum swing adsorption (VSA) process using activated carbon as the adsorbent, and the second stage is a solvent scrubber/stripper system using monoethanolamine (30 wt-%) as the solvent. The results showed that the adsorption process could enrich CO2 in the flue gas from 12 to 50 mol-% with a CO2 recovery of >90%, and the concentrated CO2 stream fed to the solvent scrubber had a significantly lower volumetric flowrate. The increased CO2 concentration and reduced feed flow to the absorption section resulted in significant reduction in the diameter of the solvent absorber, bringing the size of the absorber from uneconomically large to readily achievable domain. In addition, the VSA process could also remove most of the oxygen initially existed in the feed gas, alleviating the downstream corrosion and degradation problems in the absorption section. The findings in this work will reduce the technical risks associated with the state-of-the art solvent absorption technology for CO2 capture and thus accelerate the deployment of such technologies to reduce carbon emissions. 相似文献
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Three gas separation technologies,chemical absorption,membrane separation and pressure swing adsorption,are usually applied for CO2 capture from flue gas in coal-fired power plants.In this work,the costs of the three technologies are analyzed and compared.The cost for chemical absorption is mainly from $30 to $60 per ton(based on CO2 avoided),while the minimum value is $10 per ton(based on CO2 avoided).As for membrane separation and pressure swing adsorption,the costs are $50 to $78 and $40 to $63 per ton(based on CO2 avoided),respectively.Measures are proposed to reduce the cost of the three technologies.For CO2 capture and storage process,the CO2 recovery and purity should be greater than 90%.Based on the cost,recovery,and purity,it seems that chemical absorption is currently the most cost-effective technology for CO2 capture from flue gas from power plants.However,membrane gas separation is the most promising alternative approach in the future,provided that membrane performance is further improved. 相似文献
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Shreenath Krishnamurthy Vemula Rama Rao Sathishkumar Guntuka Paul Sharratt Reza Haghpanah Arvind Rajendran Mohammad Amanullah Iftekhar A. Karimi Shamsuzzaman Farooq 《American Institute of Chemical Engineers》2014,60(5):1830-1842
The capture and concentration of CO2 from a dry flue gas by vacuum swing adsorption (VSA) has been experimentally demonstrated in a pilot plant. The pilot plant has the provision for using two coupled columns that are each packed with approximately 41 kg of Zeochem zeolite 13X. Breakthrough experiments were first carried out by perturbing a N2 saturated bed with 15% CO2 and 85% N2 feed, which is representative of a dry flue gas from coal‐fired power plants. The breakthrough results showed long plateaus in temperature profiles confirming a near adiabatic behavior. In the process study, a basic four‐step vacuum swing adsorption (VSA) cycle comprising the following steps: pressurization with feed, adsorption, forward blowdown, and reverse evacuation was investigated first. In the absence of any coupling among the steps, a single bed was used. With this cycle configuration, CO2 was concentrated to 95.9 ± 1% with a recovery of 86.4 ± 5.6%. To improve the process performance, a four‐step cycle with light product pressurization (LPP) using two beds was investigated. This cycle was able to achieve 94.8 ± 1% purity and 89.7 ± 5.6% recovery. The Department of Energy requirements are 95% purity and 90% recovery. The proposed underlying physics of performance improvement of the four‐step cycle with LPP has also been experimentally validated. The pilot plant results were then used for detailed validation of a one‐dimensional, nonisothermal, and nonisobaric model. Both transient profiles of various measured variables and cyclic steady state performance results were compared with the model predictions, and they were in good agreement. The energy consumptions in the pilot plant experiments were 339–583 ± 36.7 kWh tonne?1 CO2 captured and they were significantly different from the theoretical power consumptions obtained from isentropic compression calculations. The productivities were 0.87–1.4 ± 0.07 tonne CO2 m?3 adsorbent day?1. The results from our pilot plant were also compared with available results from other pilot plant studies on CO2 capture from flue gas. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1830–1842, 2014 相似文献
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为减缓气候变化,减少CO2的排放,对真空变温吸附(TVSA)从干烟道气中捕集CO2进行了系统的研究。以沸石13X为吸附剂,设计了实验室规模的4塔连续进料的TVSA工艺,并建立数学模型进行数值模拟。模拟结果表明,通过四塔TVSA可获得纯度为97.54%,回收率为96.79%的CO2产品气,其产率为1.7 mol· -1·h-1,能耗为3.14 。此外,考察了进料量、循环回流步骤时间、真空度对产品气纯度、回收率、吸附剂产率和工艺能耗的影响,并且分析了塔内压力与温度变化,详细探讨了塔内气固相浓度随轴向的分布。良好的工艺效果表明,TVSA有潜力成为一种能够生产高纯度高回收率的CO2产品气,并具有良好经济效益的捕碳工艺。 相似文献
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Assessing vacuum swing adsorption (VSA) technology for postcombustion CO2 capture and concentration (CCC) using energy and productivity indicators are useful, but its ultimate test must be the cost of electricity from a power plant including CCC. Here, our integrated optimization platform (Khurana and Farooq, AlChE J. 2017;63:2987–2995) developed earlier to simultaneously obtain the optimum adsorbent and process conditions is extended to include a comprehensive costing framework. The framework is complete with scale-up design and column scheduling, and compliant with National Energy Technology Laboratory costing guidelines for carbon capture. This is the ultimate tool that enables integrated optimization to minimize the cost of electricity. The Shell Cansolv CO2 capture system is used as the benchmark for evaluating the best performance of two VSA cycles for two adsorbents. The operating conditions and isotherm shapes necessary to achieve the lowest possible cost of electricity for the two VSA cycles are also presented to facilitate designing or searching the best adsorbent for CCC. © 2018 American Institute of Chemical Engineers AIChE J, 65: 184–195, 2019 相似文献
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目前工业上主要通过变压吸附技术从蒸汽甲烷重整气中制取氢产品气。然而,能源需求量的快速增加使得传统变压吸附技术在产量方面的不足越发明显。为此,进行了快速变压吸附从蒸汽甲烷重整气中制取氢气的模拟研究。采用活性炭和5A分子筛作为吸附剂,并以测得的原料气中各组分在两种吸附剂上的吸附数据为基础,进行了六塔快速变压吸附工艺的数值模拟与分析。在分析了塔内温度、压力和固相的浓度分布后,探究了进料流量、双层吸附剂高度比以及冲洗进料比三个操作参数对于快速变压吸附工艺性能的影响,结果表明:原料气组成为H2/CH4/CO/CO2=76%/3.5%/0.5%/20%,吸附压力为22 bar(1 bar=105 Pa),解吸吹扫压力为1.0 bar,处理量为0.8875 mol·s-1,吸附剂床层高度比为0.5∶0.5,冲洗进料比为22.37%时,可获得H2纯度99.90%,回收率69.88%,此时H2产量为0.4713 mol·s-1。相比之下,氢气纯度为99.90%时,尽管PSA工艺回收率为83.40%,但处理量只有0.39 mol·s-1,因此H2产量仅为0.2472 mol·s-1。 相似文献
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The role of water on postcombustion CO2 capture by vacuum swing adsorption: Bed layering and purge to feed ratio
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Gang Li Penny Xiao Jun Zhang Paul A. Webley Dong Xu 《American Institute of Chemical Engineers》2014,60(2):673-689
The influence of water vapor on the adsorption of CO2 in carbon capture by vacuum swing adsorption (VSA) was described. VSA experiments with single and multilayered columns using alumina and zeolite 13X were conducted to understand the migration of water. The penetration depth of water in the column could be controlled by maintaining the purge‐to‐feed ratio above a critical value. At high water content in the feed (>4%), employment of a water adsorbing prelayer was essential to prevent failure of the carbon capture process. A simple axial working capacity model predicts the penetration depth of water in the column for a given feed temperature and adsorption isotherm, and the layering ratio can be selected accordingly. Although water is detrimental to CO2 capture with polar adsorbents, long‐term recovery of CO2 is still possible by appropriate layering and ensuring an adequate purge‐to‐feed ratio. © 2013 American Institute of Chemical Engineers AIChE J 60: 673–689, 2014 相似文献