费托合成钴基催化剂微观结构研究进展

费托合成可将煤、天然气及生物质等各种非石油含碳资源通过合成气转化为各种油品和精细化学品.钴基催化剂因其水煤气变换反应活性低、费托反应活性高、碳链增长能力高的优良特点,在工业应用和相关科学研究上备受关注.钴基催化剂微观活性位的结构和费托反应过程中催化剂的表面吸附物等都会对F-T合成反应的产物分布以及催化性能有影响.本文分...     

二甲醚反应化学的研究进展

随着GTL(Gas-to-Liquid)技术的发展,从煤炭或天然气经由合成气制备甲醇的反应过程已转向合成二甲醚的反应过程,最近的研究表明由合成气直接生产二甲醚能突破甲醇合成的热力学限制,实现单程的完全转化[1],其中煤基合成气一步法合成二甲醚较甲醇更具技术和经济优势.从物理性质看,     

沉淀铁催化剂在F-T合成中的研究与应用进展*

F-T合成是煤间接液化的关键工艺步骤,选择鼓泡浆态床反应器和廉价高效的铁催化剂是实现低氢碳比的煤基合成气转化的最为现实有效的产业化途径.本文对近年来国内外F-T合成技术发展进行了评述,着重介绍了用于浆态床反应器的沉淀铁催化剂的制备化学、成型方法、活性相组成、预处理条件及诸因素对F-T合成性能与工艺的影响,指出并展望了该类催化剂今后腞&D趋势与方向.     

Effect of reduction temperature on the properties and Fischer-Tropsch synthesis performance of Fe-Mo catalysts

研究了还原温度对Fe-Mo催化剂性质及费托(F-T)合成性能的影响.采用N2物理吸附、X射线衍射、穆斯堡尔谱和H2程序升温脱附技术对催化剂进行了表征.结果表明,随还原温度升高,金属铁晶粒粒径增大,金属铁上的H2吸附量先升后降;催化剂还原度提高,反应态催化剂碳化铁含量递增.催化剂F-T合成性能在280℃、1.5MPa、2000h-1、合成气H2/CO比为2.0条件下在固定床反应器中测试.反应结果表明,随还原温度提高,催化剂接近稳态时的活性和重质烃选择性(C5+)先升后降,而甲烷选择性则先降后升.350℃还原催化剂具有最佳F-T合成反应性能.     

还原温度对Fe-Mo催化剂性质及F-T合成性能的影响

研究了还原温度对Fe-Mo催化剂性质及费托(F-T)合成性能的影响。采用N₂物理吸附、X射线衍射、穆斯堡尔谱和H₂程序升温脱附技术对催化剂进行了表征。结果表明,随还原温度升高,金属铁晶粒粒径增大,金属铁上的H₂吸附量先升后降;催化剂还原度提高,反应态催化剂碳化铁含量递增。催化剂F-T合成性能在280 ℃、1.5 MPa、2 000 h^-1、合成气H₂/CO比为2.0条件下在固定床反应器中测试。反应结果表明,随还原温度提高,催化剂接近稳态时的活性和重质烃选择性(C₅⁺)先升后降,而甲烷选择性则先降后升。350 ℃还原催化剂具有最佳F-T合成反应性能。     

用于F—T合成的超细粒子催化剂及其制备化学

为提高F-T过程的汽油收率,本研究开发了一种新型工艺过程,即由合成气先转化为低碳烯烃,再将烯烃在HZSM-5分子筛上转化为高辛烷值汽油。利用超细粒子并选用适当的助剂提高了F-T过程的反应活性,选择性和热稳定性。考察了几种前躯物及助剂Mn,Zn,Mg对F-T合成的影响。由实验结果确认采用Fe/Mn草酸复盐作前躯物,经超细化处理后制得的8805催化剂活性高,选择性好,几项主要指标均已超过国内外同类催化剂水平。     

费-托合成Fe-Mo/SiO2双金属催化剂的性能

用原位穆斯堡尔谱和微型固定床反应器考察了Fe-Mo/SiO_2催化剂在还原、碳化和反应中的物相及费-托合成(F-T)反应性。富钼的Fe-Mo/SiO_2催化剂在550℃H_2中还原生成Fe-Mo合金,该合金在300℃合成气中碳化转化为Fe-Mo碳化物,是F-T反应中的主要物相。该催化剂的活性较高,其选择性体现了铁和钼的平均性质。富铁的Fe-Mo/SiO_2催化剂在550℃H_2中还原主要生成Fe~(2+),还有Fe-Mo合金和α-Fe,碳化时大部分转化为Fe~(3+),在F-T反应中的主要物相为Fe~(2+)及碳化铁,该催化剂的活性很低,其选择性类似于Fe-Mo/SiO_2。     

F-T合成催化剂羰基硫中毒热力学分析

利用热力学基础数据和相关软件对F-T合成催化剂COS中毒的热力学进行了计算。在热力学上,Ru、Fe、Co的COS中毒在F-T合成反应可以发生的条件下均是自发过程。F-T合成反应体系中10^-9级的COS即可使Ru基催化剂中的金属Ru生成RuS₂而中毒。Fe和Co毒化后生成的硫化物种类较多,对反应的热力学计算结果表明,对于不同的反应,其平衡常数的差异很大,对应中毒反应发生时,所需COS的浓度也不同。由于Fe基F-T合成催化剂活性相的复杂性,利用对催化剂相关性质的修饰开发具有一定抗硫性的铁基F-T合成催化剂是可行的;对于Co催化剂,利用F-T合成的反应特点和催化剂改性开发具有一定抗硫性催化剂也是可能的。     

Thermodynamics of carbonyl sulfide poisoning on F-T synthesis catalyst

利用热力学基础数据和相关软件对F-T合成催化剂COS中毒的热力学进行了计算.在热力学上,Ru、Fe、Co的COS中毒在F-T合成反应可以发生的条件下均是自发过程.F-T合成反应体系中10-9级的COS即可使Ru基催化剂中的金属Ru生成RuS2而中毒.Fe和Co毒化后生成的硫化物种类较多,对反应的热力学计算结果表明,对于不同的反应,其平衡常数的差异很大,对应中毒反应发生时,所需COS的浓度也不同.由于Fe基F-T合成催化剂活性相的复杂性,利用对催化剂相关性质的修饰开发具有一定抗硫性的铁基F-T合成催化剂是可行的;对于Co催化剂,利用F-T合成的反应特点和催化剂改性开发具有一定抗硫性催化剂也是可能的.     

氧化铝负载Co基F-T合成催化剂还原性能

采用XRD、TPR、XPS和H2-TPD等技术对Co/Al2O3催化剂的还原性能进行了研究.还原温度低时,催化剂中Co物种还原不充分,活化不够,催化剂的F-T合成反应活性偏低;高温还原时,由于催化剂中金属钴颗粒聚集和增大使活性组分的有效活性面积减小,催化剂的F-T合成反应活性下降.还原温度在400～500℃之间存在最佳...     

2002—Emergence of the Gas—to—Liquids Industry： a Review of Global GTL Developments

This paper reviews the status of the gas-to-liquids(TGL) industry-including current commercial plants,announced projects and the technologies that are are likely to be implemented in these future projects.Today,only 35,000 B/D of GTL products (0.1% of market) are manufactured from commercial gas-based plants,Advances in technology have lowered the cost of plants to the point where GTL phants can be profitable at crude oil prices of $16/B ,The advanced stage of development of several proposed GTL projects and attractive integrated economicws,for both the gas field and plant ,show that GTL can be a significant alternative for monetizing natural gas in the 21st centruy,GTL technologies includes more than Fischer-Tropsch technology and extends to other liquid fuels,especially in the oxygenate family (methanol,dimethyl ether ,etc.).     

The Future of Gas to Liquids as a Gas Monetisation Option

The paper introduces gas to liquids (GTL) as a monetising option from a technology, marketingand project perspective. GTL is complementary to LNG and pipelines. At the same time, using naturalgas as a source for fuels in the form of GTL helps countries around the world to diversify their energysupplies. Furthermore, gas-based products are inherently cleaner than oil products. Shell‘s proprietary GTL technology or SMDS (Shell Middle Distillates Synthesis), is discussed in some detail. The paperalso covers the challenges for successful implementation of GTL projects and why Shell is well positionedto take a lead in the industry on the basis of its long standing and broad experience in GTL research,plant operations, marketing and excellent track record in mega projects in the last thirty years. Shell‘scommitment to GTL is best demonstrated by the recent signing of a Heads of Agreement with Qatar Petroleum for the construction of the world‘s largest GTL plant. A key success factor is Shell‘s experiencewith marketing quantities of high quality GTL products from its 12,500 barrels per day plant at Bintulu,Malaysia since 1993. Further marketing opportunities will arise when new GTL capacity comes on-streamin the middle east when more quantities will become available to bulk users. Amongst the most interesting market will be automotive transportation, where clean GTL fuels can be positioned as an ‘alternativefuel beyond oil‘ providing energy security to host countries. Shell is actively engaging with a numberof regulators, automotive companies and governments worldwide including China, to demonstrate theperformance of GTL and its cost effectiveness in reducing local emissions. An added benefit is that GTLcan use existing infrastructure and requires no investment. Finally, the paper briefly discusses the coal toliquids (CTL) process as an alternative route to produce high quality GTL products and the key issuesrelating to the process.     

Gas-to-liquid technologies

Gas-to-liquid technologies (GTL) involve a two-step, indirect conversion of natural gas to higher hydrocarbons ranging from LPG to paraffin wax. The worldwide growing interest in GTL is determined by the possibility to obtain clean diesel, naphtha, lubes, olefins, and other organics form natural gas. A brief review of the state of the art in GTL is presented, including basics of syngas manufacturing and hydrocarbons synthesis. A comprehensive analysis of iron and cobalt Fischer-Tropsch catalysts in terms of their activity, stability, and product selectivity is given. Manufacturing principal GTL products and their quality and market perspectives are also discussed.     

Nanostructured Catalyst for Fischer–Tropsch Synthesis

Fischer–Tropsch synthesis (FTS) is a heterogeneous catalytic process for the production of fuels or chemicals from synthesis gas (CO + H₂), which can be derived from nonpetroleum feedstocks such as natural gas, coal, or biomass. Co, Ru, Fe and Ni are all active in FTS, but only cheaper Fe and Co based catalysts are used in industry because the price of Ru is relatively high. However, the industrial Fe‐ and Co‐ based FTS catalysts normally work at a relatively high temperature range of 493—623 K in order to get a reasonable space time yield. Moreover, the product selectivity of FTS is governed by the law of polymerization, i.e., a so‐called Anderson‐Schulz‐Flory distribution holds, which restricts its industrial application. In this account, we highlight some of our progress toward the design/fabrication of nanostructured Fe, Co and Ru catalysts to improve FTS activity at the low temperature and to change the product selectivity and confine the product distribution into a certain range.     

Fischer-Trospch Synthesis on Ordered Mesoporous Cobalt-Based Catalysts with Compact Multichannel Fixed-Bed Reactor Application: A Review

CO hydrogenation to hydrocarbons through Fischer–Tropsch synthesis (FTS) reaction is one of the promising chemical processes, which can convert alternative feedstocks such as natural gas or biomass into synthetic fuels. The FTS reaction has received many attentions due to a limited petroleum resource with an increased demand for using alternative carbon sources such as stranded gas or shale gas. Some proper synthetic methods of an effective FTS catalyst having a larger active metal surface area and a lower deactivation rate are the most important issues for a long-term operation. Therefore, some ordered mesoporous materials (OMM) have been widely investigated in the field of CO hydrogenation using some heterogeneous catalysts. The present brief review paper summarized the various preparation methods of the ordered mesoporous materials for the possible applications of FTS reaction with a lower deactivation rate and a higher catalytic performance. The applications of the ordered mesoporous cobalt oxides for FTS reaction are briefly introduced and the ways to improve a structural stability even under reductive CO hydrogenation conditions by using efficient pillaring materials as well as by preparing mixed metal oxides. A higher catalytic activity of the ordered mesoporous cobalt oxide was also verified in a multi-channel fixed-bed compact reactor having the intersected interlayers of micro-channel heat exchanger. The thermal stability of ordered mesoporous cobalt-based catalysts was mainly affected by a structural stability which can easily remove the heavy hydrocarbons from the inner surfaces.     

Effect of Potassium Addition on Coprecipitated Iron Catalysts for Fischer-Tropsch Synthesis Using Bio-oil-syngas

The effects of potassium addition and the potassium content on the activity and selectivity of coprecipitated iron catalyst for Fischer-Tropsch synthesis (FTS) were studied in a fixed bed reactor at 1.5 MPa, 300 o C, and contact time (W=F) of 12.5 gcath/mol using the model bio-oil-syngas of H2/CO/CO2/N2 (62/8/25/5, vol%). It was found that potassium addition increases the catalyst activity for FTS and the reverse water gas shift reaction. Moreover, potassium increases the average molecular weight (chain length) of the hydrocarbon products. With the increase of potassium content, it was found that CH4 selectivity decreases and the selectivity of liquid phase products (C5+) increases. The characteristics of FTS catalysts with different potassium content were also investigated by various characterization measurements including X-ray diffraction, X-ray photoelectron spectroscopy and Brunauer-Emmett-Teller surface area. Based on experimental results, 100Fe/6Cu/16Al/6K (weight ratio) was selected as the optimal catalyst for FTS from bio-oil-syngas. The results indicate that the 100Fe/6Cu/16Al/6K catalyst is one of the most promising candidates to directly synthesize liquid bio-fuel using bio-oil-syngas.     

压力对塔里木原油四组分热解性能的影响

压力对深层油藏原油热化学过程的影响尚存在较大争议,为研究其在油藏原油热解成气过程中的作用机理,我们在450℃、5~40 MPa压力下对塔里木原油四组分(饱和分、芳香分、胶质和沥青质)进行了封闭体系的热解实验,通过气相色谱(GC)和气相色谱/质谱(GC/MS)分别对原油四组分热解反应的气体产物及饱和分热解过程的液态产物进行了分析。结果表明,在450℃、24 h及不同压力下,沥青质热解产气率高于胶质、芳香分和饱和分;四组分的气相热解产物中,C1的产率明显高于C2~C5组分。增大压力抑制沥青质、胶质及芳香分的热解产气过程而促进饱和分的热解产气过程。随压力的增大,饱和分热解的液态产物的主峰组分碳数先减小,再增大。压力低于20 MPa时,饱和分热解过程中以裂解反应为主;高于30 MPa时,增大压力有利于缩合反应。研究结果可为认识深层油藏原油的稳定程度及天然气的成因提供一定的理论参考。     

Purification Influence of Synthesis Gas Derived from Methanol Cracking on the Performance of Cobalt Catalyst in Fischer-Tropsch Synthesis

1. Introduction Fischer-Tropsch synthesis (FTS) has gained in- dustrial attention for converting synthesis gas to high- boiling points waxes that can be further converted to sulfur-free motor fuels by hydrogenation or hydroc- racking as alternative resour…     

Influence of the Feed Gas Composition on the Fischer-Tropsch Synthesis in Commercial Operations

Key technical challenges relating to the Fischer-Tropsch(F-T)synthesis applied in the commer- cialization of coal/gas-to-liquids(CTL/GTL)technolo- gies have been reviewed.Based on the experiences ac- cumulated from pilot plant,semi-work test and lab re- searches,the influences of the H_2/CO ratio and the CO_2 in the feed gas on the F-T process as well as on CTL/GTL complex in terms of product yields,energy efficiency and carbon utilization efficiency have been studied.Being contrary to the current design schemes for F-T process using the coat derived syngas and the iron-based cata- lyst,it is suggested to feed the F-T synthesis unit with a syngas having a H_2/CO ratio of 0.5 and then adjusting to 1.4 via the recycling process.As a result,the carbon efficiency of the whole plant could be reached to as high as 50%.For the issue of CO_2 addition to the feed gas, it is proved that only a diluting role is played under the current commercial slurry phase F-T process.     

Isothermal Kinetics Modelling of the Fischer-Tropsch Synthesis over the Spray-Dried Fe-Cu-K Catalyst

The isothermal kinetics of the Fischer-Tropsch synthesis (FTS) over Fe-Cu-K spray-dried catalyst was studied in a spinning basket reactor. The experiments were carried out at a constant temperature of 523 K, n(H2)/n(CO) feed ratios of 0.8-2.0, reactor pressures of 1.1-2.5 MPa, and space velocity of 0.556×10-3 Nm3/kgcat·s. Kinetic model for hydrocarbon formation was derived on the basis of simplified carbide mechanism to reduce the number of parameters. Two individual rate constants for methane and ethene were considered. Furthermore, the model was modified empirically by non-intrinsic effect, such as physisorption and fictitious olefin pressures that were taken into account, and the influences of secondary reaction of α-olefins on product distribution. The simulation results showed that the experimental phenomena of FTS and the deviations from ASF distribution, such as the relatively high yield of methane and low yield of ethene observed experimentally could be depicted basically.