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在填料吸收塔中考察了Na2CO3溶液吸收高浓度H2S气体的气液传质特性。通过测量填料塔进出口气体中H2S浓度计算了Na2CO3溶液吸收高浓度H2S气体的总体积传质系数(KGa),并研究了进气流速、吸收液流量、吸收温度和吸收液浓度对KGa的影响。结果表明,KGa随Na2CO3浓度、吸收液流量的增加而增加,随吸收温度、进气流速的升高而降低;在高浓度H2S吸收过程中液相传质阻力不能忽略。 相似文献
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《环境工程学报》2016,(2)
在自制的1,8-二氮杂双环[5,4,0]十一碳-7-烯(DBU)吸收CO2的填料塔中,研究DBU溶液浓度、入口CO2浓度、DBU溶液流量、气体流量、气体温度以及填料层高度对CO2吸收的影响。结果表明,DBU溶液浓度从1.5%增加到25%,CO2吸收容量和吸收效率均逐步减小;入口CO2浓度从4.5%增加到15%,CO2吸收容量和吸收效率均逐渐增大;DBU溶液流量从20 m L/min增加到120 m L/min,CO2吸收容量和吸收效率略有增加;气体流量从0.7 L/min增加到3.3 L/min,填料层高度从5 cm增加到45 cm,CO2吸收容量和吸收效率均呈先增后减趋势;气体温度从25℃增加到60℃,CO2吸收容量和吸收效率略有下降。DBU溶液在填料塔内能够高效吸收气体中的CO2。 相似文献
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膜吸收法处理高浓度甲醛废气资源化技术研究 总被引:3,自引:2,他引:1
采用疏水性中空纤维膜接触器,以NaHSO3为吸收液处理高浓度甲醛废气。研究了吸收液流量、吸收液温度、吸收液浓度、气体进口流量和气体进口浓度等因素对甲醛去除率和总传质系数的影响。结果表明,当吸收液流量为4.17×10-6m3/s,吸收液温度为60℃,甲醛进气流量为3.7×10-6m3/s,甲醛进气浓度为566 mg/m3时,甲醛出气浓度可低至2.8 mg/m3,甲醛的去除率可达99.5%,总传质系数为4.46×10-5m/s。反应产物(ɑ-羟基磺酸钠)易分离,并可作为重要的有机合成原料或用于制备高纯甲醛而得到充分利用,NaHSO3溶液经适当稀释后仍可作为吸收液循环使用。表明膜吸收法可基本实现高浓度甲醛废气处理的资源化。 相似文献
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中空纤维膜吸收甲苯气体 总被引:1,自引:1,他引:0
采用疏水性聚偏氟乙烯(PDVF)中空纤维膜为气液接触膜,n-甲酰吗啉(NFM)水溶液为吸收剂,研究了膜吸收技术分离甲苯/空气混合气的性能。考察了进气气体浓度、气体停留时间、吸收液体积分数和吸收液流量等诸因素对分离性能的影响。研究结果表明,膜吸收技术可以有效地分离甲苯/空气混合气,甲苯去除率可达90%;提高NFM吸收液的浓度和流量可同时增加甲苯的去除效率η和总传质系数K;气体停留时间的减小导致η降低,K反而增大;进气甲苯浓度的增加导致η下降,同时降低总传质系数K。 相似文献
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《环境工程学报》2017,(11)
对厌氧发酵所产沼气中的硫化氢(H2S)生物法去除进行了实验研究。结果表明,喷淋液流量、进气H2S浓度、反应温度、进气流量和溶解氧5个因素的较优值分别为40 mL·min~(-1)、3 000 mg·L~(-1)、31℃、120 mL·min~(-1)和0.5 mg·L~(-1)。当反应温度为31℃、溶解氧浓度为0.5 mg·L~(-1)时,通过正交实验确定的因素主次顺序分别是进气流量、喷淋液流量、进气H2S浓度,相应的最佳水平值分别为60 mL·min~(-1)、60 mL·min~(-1)和1 500 mg·L~(-1)。在最优工艺条件下,该生物系统的H2S去除率稳定,可达100%。 相似文献
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化学吸收法是目前烟气回收CO2技术的研究热点,其中一类重要的吸收剂就是醇胺复合溶液.醇胺复合溶液具有对CO2吸收速率快、吸收容量大及再生简单的特点,成为烟气CO2吸收剂的首选.采用中试连续实验装置,以N-甲基二乙醇胺(MDEA)/哌嗪(PZ)/羟乙基乙二胺(AEEA)(摩尔比为0.70:0.15:0.15)三元复合溶液为吸收剂对烟气中CO2进行吸收处理.研究结果表明,吸收剂最佳摩尔浓度为3.0 mol/L,最佳吸收温度为40℃,最佳液气比为10 L/m3;再沸器的热负荷随着吸收温度、吸收剂浓度以及液气比的增加而增大,脱碳率随着入口烟气中CO2浓度的增加而降低. 相似文献
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为了降低工业废气中的硫化氢去除工艺成本和运行费用,对三价铁盐吸收与氧化亚铁硫杆菌对Fe2+的生物氧化联合作用脱除H2S进行了研究。通过生物氧化塔中的固定化氧化亚铁硫杆菌细胞再生的Fe3+溶液,在H2S还原吸收塔中脱除H2S。通过单因素实验分别优化了生物氧化塔和H2S吸收塔的运行参数,在生物氧化塔曝气量为150 L/h,停留时间为11 h,吸收液中Fe3+浓度为0.121~0.143 mol/L,吸收液流量为0.3 L/h,进气量为100 L/h条件下,进气中H2S浓度分别为2.28和9.11 mg/L,系统连续运行至200 min时趋于相对稳定,当系统连续运行稳定时,H2S的脱除率可分别达到95%和91%,脱除效果显著。 相似文献
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《Journal of environmental science and health. Part. B》2013,48(5):663-679
In order to remove high concentrations of hydrogen sulfide (H2S) gas from anaerobic wastewater treatments in livestock farming, a novel process was evaluated for H2S gas abatement involving the combination of chemical absorption and biological oxidation processes. In this study, the extensive experiments evaluating the removal efficiency, capacity, and removal characteristics of H2S gas by the chemical absorption reactor were conducted in a continuous operation. In addition, the effects of initial Fe2 + concentrations, pH, and glucose concentrations on Fe2 + oxidation by Thiobacillus ferrooxidans CP9 were also examined. The results showed that the chemical process exhibited high removal efficiencies with H2S concentrations up to 300 ppm, and nearly no acclimation time was required. The limitation of mass‐transfer was verified as the rate‐determining step in the chemical reaction through model validation. The Fe2 + production rate was clearly affected by the inlet gas concentration as well as flow rate and a prediction equation of ferrous production was established. The optimal operating conditions for the biological oxidation process were below pH 2.3 and 35°C in which more than 90% Fe3 + formation ratio was achieved. Interestingly, the optimal glucose concentration in the medium was 0.1%, which favored Fe2 + oxidation and the growth of T. ferrooxidans CP9. 相似文献
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旋转填料床/柠檬酸盐法吸收-解吸SO2 总被引:1,自引:1,他引:0
提出采用旋转填料床结合柠檬酸盐法脱除烟气中SO2的方法,考察了旋转填料床转子转速、液气比、初始柠檬酸根浓度和初始pH值等因素对脱硫效率的影响。结果表明,采用超重力法超重机转子转速为1 000 r/min、液气比为7L/m3、初始柠檬酸根浓度为1.5 mol/L、吸收液的初始pH值为5.0,脱硫效率稳定在99%左右。研究了水蒸气汽提法解吸SO2时初始柠檬酸根浓度、初始pH值、SO2浓度、富液流量和水蒸气流量对解吸效率的影响,得出了影响SO2解吸率的基本规律,并进行了分析。通过实验证明该方法在技术上是可行的,具有良好的应用前景。 相似文献
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Kim Jones Alvaro Martinez Mohammad Rizwan Jim Boswell 《Journal of the Air & Waste Management Association (1995)》2013,63(4):415-420
Abstract Two types of media, a natural medium (wood chips) and a commercially engineered medium, were evaluated for sulfur inhibition and capacity for removal of hydrogen sulfide (H2S). Sulfate was added artificially (40, 65, and 100 mg of S/g of medium) to test its effect on removal efficiency and the media. A humidified gas stream of 50 ppm by volume H2S was passed through the media-packed columns, and effluent readings for H2S at the outlet were measured continuously. The overall H2S baseline removal efficiencies of the column packed with natural medium remained >95% over a 2-day period even with the accumulated sulfur species. Added sulfate at a concentration high enough to saturate the biofilter moisture phase did not appear to affect the H2S removal process efficiency. The results of additional experiments with a commercial granular medium also demonstrated that the accumulation of amounts of sulfate sufficient enough to saturate the moisture phase of the medium did not have a significant effect on H2S removal. When the pH of the biofilter medium was lowered to 4, H2S removal efficiency did drop to 36%. This work suggests that sulfate mass transfer through the moisture phase to the biofilm phase does not appear to inhibit H2S removal rates in biofilters. Thus, performance degradation for odor-removing biofilters or H2S breakthrough in field applications is probably caused by other consequences of high H2S loading, such as sulfur precipitation. 相似文献
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Atul C. Sheth Chandramouli Sastry Yaw D. Yeboah Yong Xu Pradeep Agarwal 《Journal of the Air & Waste Management Association (1995)》2013,63(4):451-460
Abstract Catalyst recovery studies were conducted for gasified chars produced from steam gasification of Illinois #6 coal catalyzed with two different catalyst systems. A ternary (43.5 mol% Li2 CO3 –31.5 mol% Na2 CO3 –25 mol% K2 CO3 ) and a binary (29 mol% Na2 CO3 –71 mol% K2 CO3 ) eutectic catalyst system were used for gasifying coal. Various extraction schemes, such as water extraction, H2 SO4 extraction, and acetic acid extraction, were evaluated with respect to their extraction efficiencies. Effects of major process variables, such as solvent-to-char ratio, mixing time, temperature, and concentration, on the extraction efficiency were evaluated. A process schematic for the entire catalyst recovery, regeneration, and recycle scheme was developed and the preliminary process economics were determined based on these extraction schemes. H2 SO4 extraction was found to be the most desirable. It also turned out to be more attractive than a once-through throwaway system. 相似文献
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Biotreatment of various ratios of H2S and NH3 gas mixtures was studied using the biofilters, packed with co-immobilized cells (Arthrobacter oxydans CH8 for NH3 and Pseudomonas putida CH11 for H2S). Extensive tests to determine removal characteristics, removal efficiency, removal kinetics, and pressure drops of the biofilters were performed. To estimate the largest allowable inlet concentration, a prediction model was also employed. Greater than 95% and 90% removal efficiencies were observed for NH3 and H2S, respectively, irrespective of the ratios of H2S and NH3 gas mixtures. The results showed that H2S removal of the biofilter was significantly affected by high inlet concentrations of H2S and NH3. As high H2S concentration was an inhibitory substrate for the growth of heterotrophic sulfur-oxidizing bacteria, the activity of H2S oxidation was thus inhibited. In the case of high NH3 concentration, the poor H2S removal efficiency might be attributed to the acidification of the biofilter. The phenomenon was caused by acidic metabolite accumulation of NH3. Through kinetic analysis, the presence of NH3 did not hinder the NH3 removal, but a high H2S concentration would result in low removal efficiency. Conversely, H2S of adequate concentrations would favor the removal of incoming NH3. The results also indicated that maximum inlet concentrations (model-estimated) agreed well with the experimental values for space velocities of 50–150 h−1. Hence, the results would be used as the guideline for the design and operation of biofilters. 相似文献
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Chia Hao Hsu Chorng Ming Cho 《Journal of the Air & Waste Management Association (1995)》2013,63(2):246-252
Abstract The removal system for the absorption of CO2 with amines and NH3 is an advanced air pollution control device to reduce greenhouse gas emissions. Absorption of CO2 by amines and NH3 solutions was performed in this study to derive the reaction kinetics. The absorption of CO2 as encountered in flue gases into aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), and NH3 was carried out using a stirred vessel with a plane gas-liquid interface at 50 °C. Various operating parameters were tested to determine the effect of these variables on the absorption kinetics of the reactants in both gas and liquid phases and the effect of competitions between various reactants on the mass-transfer rate. The observed absorption rate increases with increasing gas-liquid concentration, solvent concentration, temperature, and gas flow rate, but changes with the O2 concentration and pH value. The absorption efficiency of MEA is better than that of NH3 and DEA, but the absorption capacity of NH3 is the best. The active energies of the MEA and NH3 with CO2 are 33.19 and 40.09 kJ/mol, respectively. 相似文献
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玻璃减薄蚀刻液中氟硅酸的选择性脱除方法 总被引:1,自引:0,他引:1
光电玻璃减薄蚀刻液中氟硅酸(H2SiF6)的累积,是导致蚀刻液无法连续使用而转化为废液的主要原因。尝试对蚀刻废液中氟硅酸进行选择性脱除工艺,探索刻蚀液循环利用的有效处理方法。鉴于氟硅酸的碱金属盐具有溶解度较低的特点,研究考察了利用钠盐或钾盐为沉淀剂,将废液中的H2SiF6以氟硅酸盐的形式沉淀去除,为实现蚀刻液的循环利用提供可能。结果表明,KCl相比NaCl对H2SiF6处理效果更好,但生成的K2SiF6的结晶颗粒过细,难以自然沉降,过滤效果较差;而Na2SiF6结晶沉降特性较好,且使用NaCl为沉淀剂具有价廉易得等特点,可作为氟硅酸的理想沉淀剂。H2SiF6去除率与碱金属盐H2SiF6摩尔计量比正相关,当摩尔计量比NaCl/H2SiF6=2,H2SiF6含量10%的模拟废液,其H2SiF6去除率可达到90%以上。 相似文献