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1.
基于化学链气化技术依靠气固反应定向调控气化产物中H 2S和SO 2摩尔比为2的优势,将化学链气化与Claus工艺中的催化转化单元相结合,提出了高硫石油焦化学链气化制合成气和回收硫磺的新系统。针对系统核心单元,即化学链气化过程,基于Aspen Plus,开展热输入10 MW th的高硫石油焦化学链气化过程模拟,以赤铁矿石为载氧体,水蒸气为气化介质,重点考察了氧碳比、气化温度对化学链气化过程及硫转化过程的影响。结果发现,氧碳比的增大导致合成气产率显著降低,但系统从需要外部提供能量逐渐转变为对外部放热,在氧碳比0.8669~0.9535区间内,系统可以达到热量自平衡。同时,气化温度的提高对合成气产率是有利的,在975℃时达到2.15 m 3/kg,主要是由于CO体积分数随气化温度增加而增加。氧碳比和气化温度的提高都会导致H 2S浓度的降低和SO 2浓度的提高。并且研究了当H 2S和SO 2摩尔比为2的最佳工况时,氧碳比和气化温度为反相关,其中氧碳比为0.8669,气化温度为900℃时,冷煤气效率为64.09%。 相似文献
2.
The main disadvantage of the Claus process is that by introducing air as oxidant a large volume of tail gas is produced. This must be treated to reduce atmospheric emissions of sulfur-containing gases. The costs of the tail-gas unit are a significant fraction of the total capital and operating costs for sulfur recovery. A new process uses thermal decomposition of hydrogen sulfide in the presence of carbon dioxide instead of air oxidation. The products of this reaction are hydrogen, carbon monoxide, elemental sulfur, water vapor and carbonyl sulfide. Carbonyl sulfide is easily converted to H 2S and C0 2 by liquid- or vapor-phase hydrolysis. Unreacted H 2S and C0 2 are recovered by absorption and recycled to the reactor. Since no air is introduced, there is no tail gas and the tail-gas unit is eliminated, giving a substantial reduction in capital investment. The concentrations of sulfur-containing gases in the product streams depend only on the operation of the absorber and stripper units and can be controlled to very low levels by increasing stripper boil-up. Process operating costs depend on the level of sulfur recovery required and can also be much lower than those of the modified Claus Process.
The process chemistry depends on a shift in the equilibrium of H 2S decomposition caused by reaction of hydrogen with C0 2 by the reverse of the water-gas-shift reaction. Catalysts for this chemistry have been identified. Reactor conversion is further improved by rapid cooling of the reactor effluent gas. Other aspects of process design and operation confer further advantages with respect to the Claus process; however, the process equipment used is similar to that used in a Claus plant. Retrofit of existing plant to the new technology can therefore be considered. 相似文献
3.
用N 2和H 2S的混合气模拟含硫天然气, 以铁基脱硫剂为脱硫液, 采用超重力旋转填充床(RPB)进行脱除H 2S的集约化实验研究, 考察了原料气H 2S质量浓度、含硫原料气流量、脱硫液流量、温度及RPB转子转速对H 2S脱除率的影响。实验结果表明, 铁基脱硫剂超重力法脱除H 2S的较佳工艺条件为原料气H 2S含量14g/m 3, 原料气流量0.45m 3/h, 脱硫液流量13.5L/h, 脱硫液温度40℃, RPB转子转速1000r/min。在此条件下, H 2S脱除率稳定在99.98%以上, 脱硫后净化气H 2S含量小于2mg/m 3。另外, 舍弃再生用RPB, 采用直接向脱硫富液储槽鼓空气的方法, 脱硫剂氧化再生良好, 脱硫效果保持不变, 且可长时间稳定运行。因此, 铁基脱硫剂超重力法脱硫工艺简单、效率高、设备体积小, 可实现海洋油气平台天然气或石油伴生气脱硫的集约化, 工业化应用前景广阔。 相似文献
4.
Properties of the oxidized activated carbon KAU treated at different temperatures in inert atmosphere were studied by means of DTA, Boehm titration, XPS and AFM methods and their catalytic activity in H 2S oxidation by air was determined. XPS analysis has shown the existence of three types of oxygen species on carbon catalysts surface. The content of oxygen containing groups determined by Boehm titration is correlated with their amount obtained by XPS. Catalytic activity of the KAU catalysts in selective oxidation of hydrogen sulfide is connected with chemisorbed charged oxygen species (O 3.1 oxygen type with BE 536.8–537.7 eV) present on the carbons surface. Formation of dense sulfur layer (islands of sulfur) on the carbons surface and removal of active oxygen species are the reason of the catalysts deactivation in H2S selective oxidation. The treatment of deactivated catalyst in inert atmosphere at 300 °C gives full regeneration of the catalyst activity at low temperature reaction but only its partial reducing at high reaction temperature. The last case is connected with transformation of chemisorbed charged oxygen species into CO groups. The KAU samples treated in flow of inert gas at 900–1000 °C were very active in H2S oxidation to elemental sulfur transforming up to 51–57 mmol H2S/g catalyst at 180 °C with formation of 1.7–1.9 g Sx/g catalyst. 相似文献
5.
The selective reduction of sulfur dioxide with hydrogen to elemental sulfur was studied over Co---Mo/Al 2O 3. When the feed conditions were properly optimized (SO 2/H 2 mole RATIO = 1:3), a sulfur yield of about 80% was achieved at temperatures around 300°C. The temperature is the lowest that has been reported so far for any catalyst for this reaction. The catalytic activity remained high and stable after presulfiding with 10% H 2S in hydrogen. Little influence on the catalytic activity was observed if the water content in the feed was kept below 11 vol.-%. The overall reaction consisted of two individual steps occurring on two different sites; sulfur dioxide was first hydrogenated to hydrogen sulfide on the metal sulfide phase, then followed by the Claus reaction of hydrogen sulfide with sulfur dioxide to produce elemental sulfur on the acidic sites of the alumina support. 相似文献
6.
This review article deals with the development of sulfur recovery from the Claus process to H 2S selective oxidation. Governments are constantly tightening regulations to limit the emission of sulfur compounds into the air. This makes it necessary to constantly enhance the level of sulfur recovery from natural, refinery, or coal gasification geses, and many improvements in the Claus process have been introduced to this end. In this review, emphasis has been put on the mechanism of reactions occurring in most of the sulfur recovery units, reactions between H 2S and SO 2 or O 2 and side reactions such as hydrolysis of COS and CS 2 or sulfation of the catalyst. 相似文献
7.
在工业二氧化碳加氢制甲醇过程中,硫化氢气体的引入将对该过程中使用的催化剂活性及稳定性带来负面的影响。基于此,采用微反应合成法成功制备了InZrO x和ZnZrO x锆基催化剂,并研究了在二氧化碳加氢反应中,硫化氢气体对锆基催化剂的结构性质及其催化性能的影响规律。结果表明,在T=573 K、p=3.0 MPa和GHSV=18 000 mL/(g cat·h)条件下,仅通入二氧化碳/氢气反应气时,InZrO x和ZnZrO x催化剂的二氧化碳转化率和甲醇选择性分别为7.2%、9.3%和93%、92%。在二氧化碳/氢气原料气中通入体积分数为5×10 -3硫化氢气体时,InZrO x和ZnZrO x催化剂的二氧化碳转化率和甲醇选择性都降为0,这主要是因为硫化氢气体占据了氧空位,导致锆基双金属氧化物催化剂硫中毒失活。当停止通硫化氢气体时,InZrO x和ZnZrO x催化剂的二氧化碳转化率和甲醇选择... 相似文献
8.
在使用单一甲基二乙醇胺(MDEA)溶液脱除天然气中H 2S的过程中,随着有机硫含量不断地增加,常常造成出料气中H 2S和总硫含量均不能满足国家二类天然气质量要求。在改变关键参数后,脱硫效果仍然不能改善。因此,本文针对高含量的有机硫,开展了MDEA+DIPA、MDEA+DEA、环丁砜+MDEA、环丁砜+DIPA 4组高效脱硫剂的复配研究,通过对比H 2S及有机硫在溶液中的吸收分压,筛选出了吸收效果较优的脱硫剂组合为:环丁砜+MDEA。随后再利用BBD响应面分析法,以环丁砜、MDEA、H 2O的不同配比为变量,以H 2S和总硫脱除率最高为目标函数进行寻优,经过混料实验与复合优化,最终得出最优脱硫剂配比为:23.3%环丁砜+54.6%MDEA+22.1%H 2O。最优配比脱硫剂经现场装置使用后的效果表明,H 2S脱除率达到99.964%,总硫脱除率达到99.833%,出料气中H 2S含量为14.4mg/m 3,总硫含量为78.5mg/m 3,满足二类气标准。 相似文献
9.
Three chemically modified/impregnated activated carbons (supplied by manufactures) were used for adsorption–catalytic removal of hydrogen sulfide from digester gas. The performance of samples was studied in dynamic conditions at 1000, 2000 and 5000 ppm of H 2S in digester gas. The results showed differences in the H 2S removal capacities related to the type of carbon and conditions of the experiment. A decrease in H 2S concentration resulted in an increase in a breakthrough capacity, which is linked to slow kinetics of oxidation process. No significant changes were observed when the oxygen content increased from 1 to 2% and the temperature from 38 to 60 °C. On the surface of carbons studied hydrogen sulfide was oxidized predominantly to sulfur, which was deposited in micropores, either on the walls or at the pore entrances. The capacities at low concentrations, 50 and 100 ppm, of H 2S were determined using an approach based on known theoretical solution of a dynamic model where the parameters of the model were determined from the experimental data at a high concentration of an adsorbate. 相似文献
10.
Mercury contamination from gas and condensate can cause concerns in the safe operation of LNG plants, LPG plants and naphtha crackers. The mercury contamination is tenacious and it is difficult to decontaminate the systems by clean gas or condensate purging. We have demonstrated in the laboratory that the systems contaminated with mercury, both from gas and liquids condensate, can be passivated effectively. The most effective passivation procedure is to discontinue the normal processing, remove the hydrocarbon from the system, inject H 2S gas into the system for adsorption and then flow with air, both at atmospheric pressure and room temperature. Because of its effectiveness, simplicity, and mild condition this process lends itself to held applications in the plants and storage tanks. The process could be implemented safely by handling H 2S carefully, injecting H 2S slowly and stopping H 2S injection as soon as the H 2S could be detected at the exit of the system.
The procedure involves three chemical steps. The H 2S is adsorbed on the Hg and then reacts with O 2 to form nascent sulfur [S], Finally, [S] reacts with Hg to form innocuous HgS. This procedure appears to be effective for all types of Hg compounds, including the organic mercury in the condensate. 相似文献
11.
The feasibility of using a cobalt-molybdenum (Co-Mo) sulfide catalyst that was prepared from a commercial Co-Mo oxide catalyst for the production of elemental sulfur from hydrogen sulfide (H 2S) and carbon dioxide (CO 2) in a packed bed catalytic reactor was studied. It was demonstrated that the desired sulfide catalyst could be prepared by first reducing, then sulphiding the corresponding oxide. The results showed that the prepared catalyst was capable of producing elemental sulfur from the thermal decomposition of H 2S in the presence of CO 2 over a temperature range of 465-700°C and at atmospheric pressure. A specific rate coefficient was calculated as well as the Arrhenius parameters for the non-equilibrated reaction. The H 2S decomposition reaction was found to be a second order reaction and have an activation energy of 114.4kJ/mol(27.3kcal/mol). 相似文献
12.
CrO x and CrO x supported on SiO 2 have been found to be active for the selective oxidation of hydrogen sulfide to elemental sulfur. The catalysts show maximum sulfur yield at a stoichiometric ratio of O 2/H 2S, 0.5. Amorphous Cr 2O 3 exhibits higher yield of sulfur and has stronger resistance against water than supported Cr/SiO 2, especially at low temperatures. At high temperatures above 300°C, the sulfur yield over the supported catalyst becomes similar to amorphous Cr 2O 3 because the Claus reaction occurring on the silica support removes SO 2 to increase the sulfur yield. Active sites are the amorphous monochromate species that can be detected as a strong temperature programmed reduction (TPR) peak at 470°C. Catalytic activity can be correlated with the amount of labile lattice oxygen and the strength of Cr–O bonding. The reaction proceeds via the redox mechanism with participation of lattice oxygen. 相似文献
13.
The room temperature wet catalytic oxidation was conducted in a batch reactor with Fe/MgO catalyst. Fe/MgO catalyst was prepared by the dissolution–precipitation method. XRD and temperature-programmed reductions (TPR) indicate that Fe oxide in the Fe/MgO is finely dispersed in the MgO support. The high H 2S removal capacities of Fe/MgO can be explained by the finely dispersed iron oxide MgO. The H 2S removal capacities of Fe/MgO are dependent on oxygen partial pressure (1.0 g H 2S/g cat in air and 2.6 g H 2S/g cat in oxygen). The valence state analysis of Fe/MgO catalyst suggests that the H 2S oxidation on Fe/MgO can occur by a redox couple reaction, reducing Fe 3+ into Fe 2+ by H 2S and oxidizing Fe 2+ to Fe 3+ by O 2. 相似文献
14.
The recovery of H 2 from H 2S is an economical alternative to the Claus process in petroleum and minerals processing industries. Previous studies [React. Kinet. Catal. Lett. 62 (1997) 55; Catal. Lett. 37 (1996) 167] have demonstrated that catalytic decomposition of H 2S over bimetallic sulfide can proceed at relatively higher rates than over mono-metallic systems due to chemical synergism although conversions are still thermodynamically limited. In the present study, the performance of a catalytic membrane reactor containing a packed bed of Ru–Mo sulfide catalyst has been investigated with a view to improving H 2 yield beyond the equilibrium ceiling. A system of differential equations describing the non-isothermal reactor model has been solved to examine the effect of important hydrodynamic and transport properties on conversion. The results were obtained using a Pt-coated Nb membrane tube as the catalytic reactor enclosed in a quartz shell cylinder. Reynolds number for shell and tube side ( Res and Ret) as well as the modified wall Peclet number, Pem, dramatically affect H 2S conversions. Membrane reactor conversion rose monotonically with axial distance exceeding the equilibrium conversion by as much as eight times under some conditions. 相似文献
15.
采用三氧化二铝或二氧化硅固体催化剂进行的最新实验室研究表明,H2Sx先在催化剂表面的碱性位分解为H2S,然后被吹扫气从液硫中驱除出去.由于H2S从气相返回液相的传质是一个有限的过程,从理论上讲,这预示着可利用克劳斯尾气作为吹扫气.试验还揭示,在涂有三氧化二铝的堇青石上,脱气期间尾气中约60%的H2S和SO2转化为元素硫.这预示着(例如)可在硫冷凝器管内衬入涂有三氧化二铝的堇青石管,以在脱气的同时提高总转化率. 相似文献
16.
采用密度泛函理论方法研究H 2S与NiFe 2O 4(001)完整表面和氧缺陷表面的相互作用机理。结果表明,H 2S在NiFe 2O 4氧载体表面Ni原子位的吸附能比其在Fe原子位的吸附能大。氧缺陷的形成会使H 2S在氧载体表面金属原子位的吸附能增大,并且Ni原子位吸附H 2S的吸附能增加更为明显。因而,NiFe 2O 4氧载体表面的Ni原子位是H 2S的主要吸附位。同时采用热力学方法进一步研究含H 2S的合成气与NiFe 2O 4氧载体之间的反应,发现H 2S与氧载体的反应产物与氧载体的还原程度密切相关。由于铁氧化物的深度还原过程受到热力学限制,H 2S与NiFe 2O 4氧载体反应的主要产物为Ni 3S 2。密度泛函理论方法与热力学方法研究结果均表明H 2S倾向于与NiFe 2O 4氧载体中Ni发生相互作用,这将对NiFe 2O 4氧载体的反应性能产生不利影响。 相似文献
17.
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H 2/CH 4/CO/CO 2=76%/3.5%/0.5%/20%,吸附压力为22 bar(1 bar=10 5 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H 2纯度99.90%,回收率69.88%,此时H 2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H 2产量仅为0.2472 mol·s -1。 相似文献
18.
The catalytic performance of some metal oxides in the selective oxidation of H 2S in the stream containing water vapor and ammonia was investigated in this study. Among the catalysts tested, V 2O 5/SiO 2 and Fe 2O 3/SiO 2 catalyst showed good conversion of H 2S with very low selectivity to undesired SO 2. Hydrogen sulfide could be recovered as harmless solid products (elemental sulfur and various ammonium salts), and distribution of solid products was varied with types of catalyst and compositions of reactant. XRD and FT-IR analysis revealed that the salt was mixture of ammonium–sulfur–oxygen compounds. It was noteworthy that V 2O 5/SiO 2 catalyst produced elemental sulfur and ammonium thiosulfate, and that elemental sulfur was principal product on Fe 2O 3/SiO 2 catalyst. Small amount of ammonium sulfate was obtained with the Fe 2O 3/SiO 2 catalyst. In order to elucidate the reaction path, the effects of O 2/H 2S ratio and concentration of NH 3 and H 2O are also studied with the V 2O 5/SiO 2 catalyst. 相似文献
19.
将H 2S和CO 2混合酸气一步转化制合成气,既实现了二者无害化处理,又生产出合成气,是一条理想的废气资源化利用新路线。由于分子结构稳定,在常规条件下因受热力学平衡限制,二者转化率极低。而在低温等离子体中,H 2S和CO 2可被激发为高活性物种来参与反应。研究了具有不同Si/Al摩尔比的ZSM-5催化剂与低温等离子体结合实现H 2S-CO 2一步高选择性制合成气,显著提高了H 2S-CO 2转化性能。考察了ZSM-5催化剂中Si/Al比和低温等离子体放电条件等对反应的影响。其中,当Si/Al比为80时表现出最优催化性能,最高H 2和CO产率分别达到56.1%和10.0%。对常规条件和低温等离子体氛围下的不同ZSM-5催化剂上CO 2、H 2S、CO、H 2等化学吸脱附行为进行了对比研究,发现低温等离子体促进了催化剂对CO 2、H 2及CO分子的吸附活化,进而明显提升了H 2S和CO 2转化。 相似文献
20.
In the partial oxidation of tar derived from the pyrolysis of cedar wood, the effect of H 2S addition was investigated over non-catalyst, steam reforming Ni catalyst, and Rh/CeO 2/SiO 2 using a fluidized bed reactor. In the non-catalytic gasification, the product distribution was not influenced by the presence of H 2S. Steam reforming Ni catalyst was effective for the tar removal without H 2S addition, however, the addition of H 2S deactivated drastically. In contrast, Rh/CeO 2/SiO 2 exhibited higher and more stable activity than the Ni catalyst even under the presence of high concentration of H 2S (280 ppm). On the Ni catalyst, the adsorption of sulfur was observed by XPS and Ni species was oxidized during the partial oxidation of tar. In the case of Rh/CeO 2/SiO 2, the adsorption of sulfur was below the detection limit of XPS. This can be related to the self-cleaning of catalyst surface during the circulation in the fluidized bed reactor for the partial oxidation of tar derived from cedar pyrolysis. 相似文献
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