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天然气(CH4)转化制得CO+H2合成气可以生产氨、甲醇及有机化工产品,需要按照转化原理进行工艺优化,以节省原料消耗,满足合成产品对组分要求。 相似文献
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我国天然气(主要成分CH4)潜在资源丰富,利用CH4进行转化生产CO+H2合成气,以生产众多的化工产品。蒸汽转化炉系特殊昂贵的关键设备,发展高效率、低造价的炉型,有其重要的经济意义。本文通过生产实践对圆筒形蒸汽转化炉进行分析总结并介绍应用前景。 相似文献
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我国天然气(主要成份CH4)潜在资源丰富,利用CH4进行转化生产CO+H2合成气,以生产众多的化工产品。蒸汽转化炉系特殊昂贵的关键设备,发展高效率,低造价的炉型,有其重要的经济意义。本文就通过生产实践对圆筒型蒸汽转化炉进行分析总结及其应用机理。 相似文献
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为满足乙二醇装置所需合成气的要求,对凯洛格天然气蒸汽转化装置进行改造,重点从方案研究、方案确定、工艺原理及流程配置等多个方面进行分析,通过选择适当的改造方案,合理调节二段转化炉氧气、CO2和水蒸气的配比,达到乙二醇合成气所需的化学当量比,满足下游产品的需求。 相似文献
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天然气制甲醇合成气工艺及进展 总被引:2,自引:0,他引:2
论述了国内外天然气制甲醇合成气各工艺的研究现状,进展及发展方向。天然气制合成气的典型工艺是水蒸气催化转化法,其技术成熟,但投资大,能耗高,生产的合成气不适于直接用来合成甲醇。天然气与CO2催化转化工艺可制得富含CO的合成气,解决蒸气转化法氢过剩的问题,实现CO2的减排,目前对该法的研究主要集中在开发新型催化剂和优化反应条件等。两段转化法即一段炉采用蒸气转化,两段炉用富氧或纯氧转化,无需经转化炉前或炉后添加二氧化碳,就可达到合成甲醇原料气成分的要求。甲烷部分氧化法能耗低,反应易控制,可制得符合比例要求的甲醇合成气,但尚未见到该技术工业化的相关报道。甲烷自热转化工艺是在反应器中耦合了放热的甲烷部分氧化反应和强吸热的甲烷蒸气转化反应,反应体系本身可实现自供热,该工艺一般采用富氧空气或氧气,因此需氧气分离装置,增加了投资,这是制约其发展和应用的主要障碍。 相似文献
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对以CO2为原料生产羰基合成气的几种方法做了综述和对比,认为通过降低水碳比,提高出口温度进行烃类,水蒸汽-CO2化是一种较为经济的工艺,以此生产羰基合成气可以有效地利用碳资源。 相似文献
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我国天然气(主要成份CH_4)潜在资源丰富,利用CH_4进行转化生产CO+H_2合成气,以生产众多的化工产品。蒸汽转化炉系特殊昂贵的关键设备,发展高效率、低造价的炉型,有其重要的经济意义。本文就通过生产实践对圆筒型蒸汽转化炉进行分析总结及其应用前景。 相似文献
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It is essential to develop the environment-friendly alternative energies urgently considering the limited fossil fuel and the global warming caused by environmental destruction. In this research, the new technology was studied to produce syngas from methane or simulated biogas with a HCCI reforming engine. The purpose is to provide the basics for the research on biogas treatment mainly comprising of methane and carbon dioxide, the cause of global warming. 相似文献
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CO2 and O2 simultaneously reforming of coke oven gas (COG) in three processes including non-catalytic process (NCP), catalytic process (CP), and two-stage process (TSP) was investigated under two important operating conditions, CO2/CH4 and O2/CH4, over Ni-based catalyst in a fixed bed reactor. It was found that the technical indexes depend strongly on CO2/CH4 and O2/CH4 in different processes. CO2 can adjust H2/CO ratio in a wider range (0.52–3.83) in the presence of O2. The conversions of CH4 increase in overall COG reforming processes by adding O2. Also, a little O2 promotes CO2 conversions in NCP and restrains CO2 conversions in CP and TSP. The addition of O2 can also adjust H2/CO ratio of syngas, which is actually at the cost of H2 consumption by oxidation rather than reverse water gas shift (RWGS) reaction. In addition, H2 combustion in the first-stage of TSP provides heat to drive the endothermic CH4 reforming reactions and RWGS reaction in the second-stage of TSP to achieve higher CH4 and CO2 conversions. Therefore, TSP precedes significantly NCP and CP in the reforming of COG. When H2/CO ratio is 2.10, the conversions of CH4 and CO2 are 98.96 and 62.32% respectively; and, oxygen consumption is 0.13 m3 per COG m3 at gas hour space velocity 9256 h−1 in TSP. 相似文献
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我国天然气(主要成分CH4)潜在资源丰富,利用CH4进行转化生产CO+H2合成气.以生产众多的化工产品.蒸汽转化炉系特殊昂贵的关键设备,发展高效率、低造价的炉型,有其重要的经济意义。本文通过生产实践对圆筒形蒸汽转化炉进行分析总结并介绍应用前景。 相似文献
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G.R. Moradi J. Ahmadpour F. Yaripour 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2008,144(1):88-95
The intrinsic kinetics of the three-phase dimethyl ether (DME) synthesis from syngas over a bi-functional catalyst has been investigated in a agitated slurry reactor at 20–50 bar, 200–240 °C and H2/CO feed ratio from 1 to 2. The bi-functional catalyst was prepared by physical mixing of CuO/ZnO/Al2O3 as methanol synthesis catalyst and H-ZSM-5 as methanol dehydration catalyst. The three reactions including methanol synthesis from CO and H2, methanol dehydration and water gas shift reaction were chosen as the independent reactions. A kinetic model for the combined methanol and DME synthesis based on a methanol synthesis model proposed by Graaf et al. [G.H. Graaf, E.J. Stamhuis, A.A.C.M. Beenackers, Kinetics of low pressure methanol synthesis, Chem. Eng. Sci. 43 (12) (1988) 3185; G.H. Graaf, E.J. Stamhuis, A.A.C.M. Beenackers, Kinetics of the three-phase methanol synthesis, Chem. Eng. Sci. 43 (8) (1988) 2161] and a methanol dehydration model by Bercic and Levec [G. Bercic, J. Levec, Intrinsic and global reaction rate of methanol dehydration over γ-Al2O3 pellets, Ind. Eng. Chem. Res. 31 (1992) 399–434] has been fitted our experimental data. The obtained coefficients in equations follow the Arrhenius and the Van’t Hoff relations. The calculated apparent activation energy of methanol synthesis reaction and methanol dehydration reaction are 115 kJ/mol and 82 kJ/mol, respectively. Also, the effects of different parameters on the reactor performance have been investigated based on the presented kinetic model. 相似文献
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Kyoungmo Koo Jaekyung Yoon Changha Lee Hyunku Joo 《Korean Journal of Chemical Engineering》2008,25(5):1054-1059
The autothermal reforming of methane to syngas for use in the Fischer-Tropsch synthesis was studied in this work over PdO
containing various combinations of CeO2, BaO or SrO in a washcoated form on a metallic monolith at atmospheric pressure. This study focused on the autothermal operation
of the system, in which an electric heater inside the reactor was used only to reach the ignition temperature, and thereafter
the autothermal reaction successfully sustained itself without any external heat source. It was concluded from the experiments
that the PdO/Al2O3 catalyst was better than the others, except for PdO-CeO2-BaO-SrO/Al2O3, which showed similar performance in terms of the CH4 conversion and H2+CO selectivity, while affording a higher H2/CO ratio (close to ca. 3) than the PdO/Al2O3 catalyst did (close to ca. 2). The gas hourly space velocity and O2/CH4 ratio governed the methane conversion, while the H2O/CH4 ratio controlled the H2/CO ratio. A methane conversion of ∼87%, H2+CO selectivity of ∼94%, H2/CO ratio of ∼2.9, and M factor ∼2.15 were obtained under the conditions of a gas hourly space velocity (GHSV) of 120,000
h−1, O2/CH4=0.6 and H2O/CH4=0.5. 相似文献
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Simulation of DME synthesis from coal syngas by kinetics model 总被引:1,自引:0,他引:1
Hyun Min Shim Seung Jong Lee Young Don Yoo Yong Seung Yun Hyung Taek Kim 《Korean Journal of Chemical Engineering》2009,26(3):641-648
DME (Dimethyl Ether) has emerged as a clean alternative fuel for diesel. There are largely two methods for DME synthesis.
A direct method of DME synthesis has been recently developed that has a more compact process than the indirect method. However,
the direct method of DME synthesis has not yet been optimized at the face of its performance: yield and production rate of
DME. In this study it is developed a simulation model through a kinetics model of the ASPEN plus simulator, performed to detect
operating characteristics of DME direct synthesis. An overall DME synthesis process is referenced by experimental data of
3 ton/day (TPD) coal gasification pilot plant located at IAE in Korea. Supplying condition of DME synthesis model is equivalently
set to 80 N/m3 of syngas which is derived from a coal gasification plant. In the simulation it is assumed that the overall DME synthesis
process proceeds with steadystate, vapor-solid reaction with DME catalyst. The physical properties of reactants are governed
by Soave-Redlich-Kwong (SRK) EOS in this model. A reaction model of DME synthesis is considered that is applied with the LHHW
(Langmuir-Hinshelwood Hougen Watson) equation as an adsorption-desorption model on the surface of the DME catalyst. After
adjusting the kinetics of the DME synthesis reaction among reactants with experimental data, the kinetics of the governing
reactions inner DME reactor are modified and coupled with the entire DME synthesis reaction. For validating simulation results
of the DME synthesis model, the obtained simulation results are compared with experimental results: conversion ratio, DME
yield and DME production rate. Then, a sensitivity analysis is performed by effects of operating variables such as pressure,
temperature of the reactor, void fraction of catalyst and H2/CO ratio of supplied syngas with modified model. According to simulation results, optimum operating conditions of DME reactor
are obtained in the range of 265–275 °C and 60 kg/cm2. And DME production rate has a maximum value in the range of 1–1.5 of H2/CO ratio in the syngas composition. 相似文献
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Co-liquefaction of lignite and sawdust under syngas 总被引:1,自引:0,他引:1
Individual and co-liquefaction of lignite and sawdust (CLLS) under syngas was performed in an autoclave and the effects of temperature, initial syngas pressure, reaction time and ratio of solvent to coal and biomass on the product distribution of CLLS were studied. Sawdust is easier to be liquefied than lignite and the addition of sawdust promotes the liquefaction of lignite. There is some positive synergetic effect during CLLS. In the range of the experimental conditions investigated, the oil yield of CLLS increases with the increase of temperature, reaction time (10-30 min) and the ratio of the solvent to the feedstock (0-3), but varies little with the increase of initial syngas pressure. Accordingly, the total conversion, the yield of preasphaltene and asphaltene (PA + A) and gas, changes by the difference in operation conditions of liquefaction. The gas products are mainly CO and CO2 with a few C1-C4 components. The syngas can replace the pure hydrogen during CLLS. The optimized operation conditions in the present work for CLLS are as follows: syngas, temperature 360 °C, initial cold pressure 3.5 MPa, reaction time 30 min, the ratio of solvent to coal and sawdust 3:1. Water gas shift reaction occurs between CO in the syngas and H2O from coal and sawdust moisture during the co-liquefaction, producing the active hydrogen which increases the conversion of liquefaction and decreases the hydrogen consumption. 相似文献
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This paper presents experimental measurements of the critical velocity gradient and flashback behavior of H2-CO and H2-CH4 mixtures. Effects of H2 concentration, external excitation, and swirl on the flashback behavior for flames of these fuel mixtures are discussed. For H2 concentration burner and scaling studies the critical velocity gradient (gF), defined as the ratio of the square of the laminar burning velocity to the thermal diffusivity of the mixture , was used to quantify the flashback propensity of the flames. The critical velocity gradient of both H2-CH4 and H2-CO flames changed nonlinearly with the increase in H2 contents in the mixture. The critical velocity gradient (gF) of 5-95% and 15-85% H2-CO mixtures somewhat agreed with the scaling relation and yielded an average c value of 0.04. Similarly, values of a 25%H2-75%CH4 for different burner diameters were also fitted using the scaling relation yielding an average c value of 0.044. The gF values of 25-75% H2-CO mixture showed non-linear variation with the ratio (especially for ), and at a lower ratios burner diameter had small effect on critical velocity gradient measurements. The opposite trend was observed for a 25-75% H2-CH4 mixture showing non-linear variation at a lower ratios (for ) and having less effect at higher ratios. It was also determined that the effect of external excitation on the flashback propensity of H2-CO flames with more than 5% H2 was not significant. Flashback through two mechanisms and their dependence on combustor parameters were also identified for swirl stabilized H2-CO flames. 相似文献
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《化学工业与工程技术》2017,(5):6-10
采用2个模拟绝热反应器串联的模试装置,对自主研发的NCJ-1宽温型催化剂与NCJ-2低温型催化剂进行了活性评价,研究了煤基合成气制SNG的反应工艺。试验采用的原料气组成(φ)为:H268.4%,CO 19.6%,CO_23.0%,CH_49.0%,考察了空速、入口温度、新鲜气中CO_2体积分数、循环比、反应压力、一反入口加水量等条件对甲烷合成的影响。试验结果表明:空速上升对反应转化率和气体出口浓度的影响不太明显,但热点位置会下移;入口温度在高于250℃的前提下,随着温度的升高热点温度急剧上升;CO_2入口体积分数上升,CO_2转化率上升;通过改变循环比可以有效控制一反入口CO_x体积分数,使反应热点温度控制在催化剂允许的范围内;随着压力升高,热点温度、CH_4出口体积分数、CO转化率、CO_2转化率均上升;一反入口加水有利于控制床层温度,并有效保护催化剂,防止积炭。 相似文献
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