微波场中的甲烷部分氧化制合成气

介绍了微波场中甲烷部分氧化制合成气反应的原理及特性,对甲烷部分氧化制合成气反应的催化剂在微波场中的性能进行了简要介绍和分析,表明了甲烷部分氧化的微波反应技术具有较好的工业应用前景。     

甲烷部分氧化制合成气的研究进展

综述了近年来甲烷部分氧化制合成气的催化剂，反应机理及活性中心的研究进展及反应中存在的主要问题。     

甲烷部分氧化制合成气催化剂的研究进展

甲烷部分氧化（POM）反应制合成气是化学利用甲烷的有效途径之一。研究表明,甲烷部分氧化反应的工艺有能耗低和反应速率较快等优点,而且所得的H2和CO的比例适于合成甲醇等工业化学品。在该工艺过程中,所需反应容器体积小,反应效率高,可大幅度降低制备合成气的成本。开发POM反应的高效催化剂是进一步提高反应效率、实现工业化的关键途径,因此,是当前国际催化领域研究的热门课题之一。本文主要介绍了传统的金属负载型催化剂和金属氧化物催化剂用于POM反应的研究进展。     

天然气甲烷部分氧化制合成气的研究进展

甲烷部分氧化制合成气是高转化率、高选择性、高空速、低H2/CO、温和的放热反应,综述了近几年来甲烷部分氧化制合成气的催化剂、反应机理及活性中心的研究进展及反应中的存在问题。     

甲烷部分氧化制合成气反应中床层热点问题研究进展

综述了甲烷部分氧化制合成气反应中催化剂床层热点问题,包括热点产生的原因,热点位置的测定,热点温度的影响因素,以及热点问题的解决方法,对于保护催化剂和反应器,降低反应的危险性起到借鉴作用.     

催化部分氧化甲烷制合成气的平衡热力学研究

The catalytic partial oxidation of methane to syngas (CO H2) has been simulated thermodynamically with the advanced process simulator PRO/Ⅱ. The influences of temperature,pressure,CH4/O2 ratio and steam addition in feed gas on the conversion of CH4 selectively to syngas and heat duty required were investigated, and their effects on carbon formation were also discussed. The simulation results were in good agreement with the literature data taken from a spouted bed reactor.     

甲烷部分氧化制合成气催化剂的研究进展

综述了甲烷部分氧化制合成气的研究意义和现状，从金属活性组分，载体效应，载量选择，助剂添加和制备方法等因素对催化剂活性的影响及研究进行了系统。结合本课题组的研究结果及文献报道，分析了Ni基催化剂的失活特性，并提出使用等离子体技术对Ni基催化剂进行改笥处理，以提高其催化稳定性的技术展望。     

甲烷催化部分氧化制合成气的研究进展

文章叙述了甲烷催化部分氧化制合成气研究的进展情况。介绍了两种主要的反应机理：间接反应机理和直接反应机理;对负载型镍系催化剂的研究现状进行了叙述,并简单介绍了非负载型催化剂;另外还对固定床、流化床、膜反应器以及一些新开发的反应器的特点进行了讨论。     

甲烷空气催化部分氧化制含氮合成气的研究

采用常规的浸渍法制备镍基催化剂,研究了甲烷空气催化部分氧化制备含氮合成气的催化性能,得到了镍含量在8％时部分氧化活性最佳;加入镧助剂使催化剂的活性和选择性达到95．3％和97．5％,通过向体系加入H2O和CO2,可以提高加压条件下甲烷的转化率并抑制催化剂积炭,可以获得n(H2):n(CO）接近２的合成气;催化剂连续使用500h性能稳定。     

甲烷空气催化部分氧化制含氮合成气的研究

采用常规的浸渍法制备了镍基催化剂和经过镧改性的镍基催化剂,研究了甲烷催化部分氧化制备含氮合成气的催化功能,结果说明,镍含量在8％时催化活性达到最好,同时加入镧进行改性后催化剂的活性和选择性有所提高;该催化剂对甲烷空气催化部分氧化制合成气在常压下具有较高的转化率,随压力升高,转化率明显下降,并且积极严重,通过向体系加入H2O和CO2可以提高加压条件下甲烷的转化率并抑制催化剂积碳,还可以获得H2／CO接近2的合成气,满足合成液体燃料的要求。     

甲烷部分氧化制合成气反应的研究

用粒度为5mm的α－Al2O3、β-Al2O3、γ-Al2O3为载体，用浸渍法制备了10％（质量）Ni基催化剂。在固定床流动反应器中，在反应温度500－850℃，大空速和不同的CH4／O2摩尔比下，测定了该催化剂用于甲烷部分氧化制合成气的活性和CO选择性。500℃用H2对催化剂还2h后，进行活性测试结果,10%Ni／β-Al2O3、Ni／γ-Al2O3对POM反应无活性，只有10％Niα－Al2O3对POM反应有活性。TPR测试结果表明，这是由于10％Ni／β-Al2O3和Ni／γ-Al2O3催化剂在700℃以下未被还原所致。另外，合成气的生成速率和CO选择尾均随反应温度和空速的增大而增大，并在CH4／O2摩尔比2时有最大值。     

甲烷空气部分氧化制合成气喷动床反应器的研究

On the basis of hydrodynamic and scaling-up studies, a pilot-plant-scale thermal spouted bed reactor (50 mm in ID and 1500 mm in height) was designed and fabricated by scaling-down cold simulators. It was tested for making syngas via catalytic partial oxidation (CPO) of methane by air. The effects of various operating conditions such as operating pressure and temperature, feed composition, and gas flowrate etc. on the CPO process were investigated. CH4 conversion of 92.20％ and selectivity of 92.3% and 83.30/0 to CO and H2, respectively, were achieved at the pressure of 2.1 MPa. It was found that when the spouted bed reactor was operated within the stable spouting flow regime, the temperature profiles along the bed axis were much more uniform than those operated within the fixed-bed regime. The CH4 conversion and syngas selectivity were found to be close to thermodynamic equilibrium limits. The results of the present investigation showed that spouted bed could be considered as a potential type of chemical reactor for the CPO process of methane.     

甲烷非催化部分氧化制乙炔和合成气过程的实验研究

通过探头取样和四极杆质谱在线测量甲烷、氧气和乙炔等组分的浓度分布,考察了氧气/甲烷(甲烷+乙烷/丙烷)摩尔比、气体预热温度及原料气中添加乙烷和丙烷对甲烷非催化部分氧化制乙炔和合成气的影响. 结果表明,随轴向距离增加,乙炔浓度先增大后减小,存在最大值;随氧气/甲烷(甲烷+乙烷/丙烷)摩尔比增加,乙炔选择性下降;升高混合气体预热温度产物中乙炔浓度增大,620℃时最大乙炔浓度为4.52%;添加乙烷和丙烷时产物中乙炔浓度基本不变,但甲烷消耗量下降. 在实验条件下,生成最大乙炔浓度的激冷位置距烧嘴出口的距离约为80 mm.     

Catalytic Partial Oxidation. Part I. Catalytic Processes to Convert Methane: Partial or Total Oxidation

The presence of large reserves of natural gas has stimulated research to utilize methane, its principal component, as an alternative energy source and to convert it to other fuels and industrially important chemicals. The reserves of natural gas in the world are estimated to be 1.4 × 10¹⁴ Nm³, while new gas fields are being discovered every year. Although this natural gas is available under pressure for piping and transport, extensive research efforts have been directed to develop gas-to-liquid (GTL) technology for the conversion of remote natural gas reserves into high-added-value liquid products, such as methanol and synthetic fuels, that can be more easily transported. A further incentive for natural gas utilization originates from environmental concerns that drive the search for cleaner energy sources. Catalytic combustion of methane offers an attractive alternative to gas-phase homogeneous combustion since it can stabilize flames at lower fuel-to-air ratios, thereby lowering flame temperatures and reducing NO_x emission. Another alternative can be found in the conversion of natural gas into hydrogen, which can be used to generate electricity in fuel cells. Fuel cells have a much higher energy efficiency compared to current combustion-based power plants. Also, hydrogen is a much cleaner fuel than hydrocarbon feedstocks since the only product from hydrogen fuel cells is water.     

Partial Oxidation of Methane to Syngas in a Packed Bed Catalyst Membrane Reactor

The planar membrane reactor configuration was explored for partial oxidation of methane (POM) to syngas. A supported membrane composed of yttria‐stabilized zirconia and La_0.8Sr_0.2Cr_0.5Fe_0.5O_3‐δ was sealed to a stainless holder, and a Ni/Al₂O₃ catalyst bed was placed under the membrane plane with a small slit between them. This reactor configuration would facilitate the POM reaction via oxidation‐reforming mechanism: the oxidation reaction occurring at the membrane surface and the reforming reaction taking place in the catalyst bed. At 800°C and a methane feed rate of 32 mL min^?1, the reactor attained methane throughput conversion over 90%, CO and H₂ selectivity both over 95%, and an equivalent oxygen permeation rate 1.4 mL cm^?2 min^?1. The membrane and catalyst remained intact after the POM testing. The planar membrane reactor configuration explored in this study may lead to the development of a compact reactor for syngas production. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2170–2176, 2016     

Catalytic Total Oxidation of Methane. Part II. Catalytic Processes to Convert Methane: Partial or Total Oxidation

The introduction of solid catalysts into a traditionally non-catalytic free-radical process such as combustion occurred in recent years under the influence of environmental pressures. The major applications of catalytic combustion are two-fold: at low temperatures to eliminate volatile organic compounds (VOCs) and at high temperatures (>1000°C) to reduce NOx emission from gas turbines, jet motors, etc. It is the high temperature application that is reviewed here. Some recent developments in high-temperature catalytic combustion are trend setters in catalysis and hence of particular interest. For instance, novel materials are being developed for catalytic applications above 1000°C for sustained operation longer than one year. Where material/catalyst developments are still inadequate, systems engineering is coming to the rescue by developing multiple-monolith catalyst systems and the so-called hybrid (catalytic + thermal) reactors.