Hydrocarbon synthesis over sulfide catalysts. Break-down of the Anderson-Schulz-Flory distribution

The kinetics of hydrocarbon synthesis over sulfide-based catalysts was studied. It appears that the formation of methane follows another reaction path than that of higher hydrocarbons. This might explain the very high selectivities for ethane and propane as compared with conventional Fischer-Tropsch catalysts. Reference is made to testing of the catalysts at industrial conditions.     

费托合成油和石油基油加工产品对比分析

费托合成及煤化工的发展能够有效缓解我国对石油资源的依赖。本文针对低温煤基合成油与传统石油基石脑油、煤油、柴油、润滑油和蜡产品性能进行对比。文章指出与传统石油基产品对比,费托合成油产品具有蜡含量高、无硫、无氮、少芳烃的特性,满足清洁油品的环保要求,同时在高档润滑油基础油和高熔点石蜡等高附加值产品生产方面更具竞争优势。但费托合成油加工的油品普遍存在凝点、冰点、密度等相关关键指标不合格问题,不同油品的生产,均需要通过异构、精制、裂化、重整等技术改善油品的低温流动性,并通过切割、掺炼等工艺改进才能生产符合标准的油品。文章提出结合我国清洁燃料消费及能源结构调整的变化,费托合成工艺和煤制油应发挥高端产品优势,延伸加工产业链,实现粗放型加工向产业链高端迈进。     

费托合成高温油相产品中正构烃的分离

以模拟的费托合成高温油相产品为原料,采用尿素包合法从原料中分离正构烃。考察了活化剂的种类、包合反应条件、解包合反应条件等对正构烃分离效果的影响。通过正交实验研究,结果表明：乙醇为较适宜的活化剂;较优反应条件为反应温度5℃,反应时间60min,以1g原料为基准,尿素用量2.75g,乙醇用量3.5mL,水用量1.125mL。在此包合反应条件下,得到1-癸烯的回收率为87.75%,正癸烷的回收率为89.90%。尿素包合物的解包合反应实验结果说明,水的存在有利于解包合反应的进行,得到正构烃回收率较高。用水量为100 mL时,尿素包合物的解包合反应基本完成。     

Fischer-Tropsch products as liquid fuels or chemicals

The compatibility between the Fischer-Tropsch Synthesis (FT) and the economic role of the petroleum refining industry is examined. The economic advantage of the FT synthesis utilized within a petroleum refinery is explored. Also examined are the chemical and physical properties of the FT products. Although the FT distillate fuels have exceptional properties, FT naphta is difficult to reform into gasoline. The refiner may choose to utilize lighter FT products in petrochemical applications when FT is viewed as a supplement, rather than an alternative to petroleum refining.     

Liquid-vapor thermodynamic equilibrium in Fischer-Tropsch synthesis products

A modified Peng-Robinson equation of state is used to develop the methods for calculating the liquid-vapor thermodynamic equilibrium in Fischer-Tropsch synthesis products. The critical thermodynamic parameters of paraffin and olefin hydrocarbons with a number of carbon atoms higher than 20 are determined using the correlations proposed in the present paper. The calculated results are compared with literature data and the data obtained in the Integrated Research and Development Center.     

费托合成产物中含氧组分资源化利用技术进展

费托合成产物中含多种高附加值含氧组分。部分较低碳数含氧化合物溶解于合成水中,使其具有酸性强、腐蚀性强、刺激性气味、直接生物处理难度大等特点。根据实际组成有针对性地进行资源化利用才能实现经济和环境效益最大化。随着煤间接液化产业发展,费托合成产物中含氧组分资源化利用技术逐渐被更多研究者关注。本文分析了不同费托工艺产生的费托合成水相组成特点,综述了以油分离、酸分离、醇类等分离为步骤的高附加值含氧组分提取分离技术的最新进展,介绍了以高级氧化法、厌氧法等为代表的适用于费托合成废水提质的最新技术研究情况。最后总结了国内外成功工业化的费托合成水相产物处理技术应用情况及实施效果,提出了费托合成产物中含氧组分资源化利用技术的未来发展方向。     

Co/AC催化剂对F-T合成醇产物的影响

以活性炭为载体,采用真空浸渍法制备Co/AC催化剂,在浆态床反应器中考察反应温度、反应压力和空速等条件对F-T合成醇产物的影响。结果表明,升高反应温度对长链烃和醇的生成有利,醇类的选择性随着反应压力的增大而提高,但反应压力增至3.0 MPa后,继续增加反应压力对醇类选择性变化不大;随着空速的增大,液相产物中醇含量虽然增加,但醇的分布无变化。     

New controlling method for product distribution in Fischer-Tropsch synthesis reaction

Addition of a small amount of heavy 1-olefin into a supercritical-phase or liquid-phase FT reaction medium could significantly promote the carbon-chain growth and greatly enhance the selectivity of waxy products, with increased CO conversion while suppressing methane selectivity. The phenomenon was not observed in the gas-phase reaction.     

高温固定流化床费托合成技术及其产物加工路线

与采用低温费托合成主产油品技术相比,产品更为多元化和高值化的高温费托合成技术在目前市场环境下显示出非常明显的优势。本文综述了高温费托合成技术的发展历程及其最新进展,重点介绍了高温费托合成过程中的核心问题,主要包括高温费托合成工艺、固定流化床反应器、费托合成催化剂;介绍了高温费托合成产物分布与特性,讨论了高温费托合成产物的加工路线,并对高温费托合成煤间接液化的工业应用前景和产业化方向进行了展望。结果表明：高温费托合成技术具有产物附加值高、兼顾油品和化学品、技术发展成熟等优势,产物中轻组分含量高、碳数分布较窄、高附加值的α-烯烃含量高;精细化、高端化、差异化加工是实现高温费托合成产物高值化利用的关键。     

Influence of the hydrocarbons distribution on the heat produced during Fischer-Tropsch synthesis

The heat produced during Fischer-Tropsch synthesis has been calculated, considering a base case in which a typical Anderson-Schulz-Flory (ASF) distribution is followed by the paraffinic hydrocarbons produced. An equation has been obtained, which allows us to calculate the enthalpy of reaction, using the probability of chain growth as the variable. The effect of a deviation from the ASF distribution has been considered, through the example of a higher methane selectivity than in the base case. The correction due to the condensation of higher hydrocarbons has also been evaluated. In order to be able to perform energy balance calculations, the physical state of water at the reactor outlet has been checked.     

Kinetics modelling of Fischer-Tropsch synthesis over an industrial Fe-Cu-K catalyst

The kinetic experiments of Fischer-Tropsch synthesis (FTS) over an industrial Fe-Cu-K catalyst are carried out in a micro-fixed-bed reactor under the conditions as follows: temperature of 493-542 K, pressure of 10.9-30.9 bar, H₂/CO feed ratio of 0.98-2.99, and space velocity of 4000-10?000 h⁻¹. The effects of secondary reactions of olefins are investigated by co-feeding C₂H₄ and C₃H₆. A detailed kinetics model taking into account the increasingly proven evidence of the olefin re-adsorption mechanism is then proposed. In this model, different sites are assumed for FTS reactions and water gas shift (WGS) reaction, respectively. Rate expressions for FTS reactions are based on the carbide polymerisation mechanism, in which olefin re-adsorption is considered to be a reverse step of olefin desorption reaction. Rate expression for WGS reaction is based on the formate mechanism. An integral reactor model considering both FTS and WGS kinetics is used to describe the reaction system, and the simultaneous estimation of kinetic parameters is conducted with non-linear regression procedure. The optimal model shows that the rate determining steps in FTS reactions proceed via the desorption of hydrocarbon products and the adsorption of CO and the slowest step in WGS reaction is the desorption of gaseous carbon dioxide via formate intermediate species. The activation energies of FTS reactions and WGS reaction are in good agreement with literature values.     

Intrinsic kinetics of the Fischer-Tropsch synthesis over an impregnated cobalt-potassium catalyst

The optimal amount of 15 wt%Co/10 wt%K/Al₂O₃ catalyst was prepared using the impregnation technique in order to study the kinetics of the Fischer-Tropsch synthesis. The rate of synthesis was measured in a fixed-bed micro reactor with H₂/CO feed ratio of 1–3 and space velocity in the range of 2,700–5,200 h⁻¹ under reactor pressure of 8 bar and a temperature range of 210–240 °C. The experimental data were best fitted by a Langmuir-Hinshelwood-Hougen-Watson (LHHW) approach rate in the form of - r_CO = (k₂ K₁ P_CO P_H2 )/(1 + K₁ P_CO ) - r_{CO} = (k_2 K_1 P_{CO} P_{H_2 } )/(1 + K_1 P_{CO} ). Furthermore, the data were fitted fairly well by a power law equation in the form of - r_CO = kP_CO^1.32 P_H2 ^1.42 - r_{CO} = kP_{CO}^{1.32} P_{H_2 }^{1.42} . The activation energies for LHHW approach model and power law equation were obtained as 138.5 kJ/mol and 87.39 kJ/mol, respectively.     

费托合成α-烯烃脱除含氧化合物方法的研究进展

综述了α-烯烃脱除含氧化合物方法的最新研究进展。目前主要的脱除方法有化学脱除、物理吸附、加氢法、溶剂萃取和精馏等。通过对比几种方法的优缺点得出:精馏法和物理吸附方法为最佳的脱除方法,含氧化合物脱除率高达99.995%。同时,指出了脱氧方法的不足以及其发展趋势。     

合成气一步法制汽油馏分烃费托合成催化剂研究进展

围绕对费托合成产物分布的有效调控,综述了近年来有关合成气一步法制汽油馏分烃(C5~C11烷烃)费托合成催化剂的研究进展。重点分析了铁、钴、钌基分子筛催化剂对C5~C11烃选择性的影响,并对费托合成一步法制汽油馏分烃催化剂的未来发展方向进行了展望。     

固定化微生物技术处理费托合成废水研究

采用固定化复合菌对煤间接制油费托合成废水进行生化处理,考察固定化微生物技术对费托合成废水中CODCr和NH_3-N的去除效果,并确定最佳的反应参数。结果表明,在初始pH值为7.0,固定化复合菌投加量为90 g/L,温度为30℃的最佳条件下,恒温振荡96 h后,废水中CODCr、NH_3-N的质量浓度分别由初始的10 512.3、30.0 mg/L降至2 094.0、4.7 mg/L,去除率分别为80.08%、84.47%。在合适的CODCr浓度范围内,固定化复合菌对废水的处理效果显著。说明固定化微生物技术对煤间接制油费托合成废水具有良好的处理效果。     

费托油品中氧化物脱除方法的研究进展

介绍了国内外费托油品中氧化物脱除的几种方法:萃取法、精馏法、吸附法、加氢法、化学法等,分析了各种方法的优缺点及研究进展。提出氧化物脱除方法的选择应基于不同氧化物脱除方法的特点和费托油品氧化物的脱除目标,指出多种方法组合的方式是未来脱除费托油品中氧化物的发展方向。     

煤间接液化技术开发现状及工业前景

评述了国内外煤经合成气间接液化合成液体燃料的开发趋势和工业化状况，讨论了煤间接液化工艺路线和需要解决的关键技术难题，分析了煤间接液化的技术经济性，展望了我国煤间接液化产业化前景。     

合成气一步法制汽油馏分烃费托合成催化剂研究进展

围绕对费托合成产物分布的有效调控,综述了近年来有关合成气一步法制汽油馏分烃(C5^C11烷烃)费托合成催化剂的研究进展。重点分析了铁、钴、钌基分子筛催化剂对C5C11烷烃)费托合成催化剂的研究进展。重点分析了铁、钴、钌基分子筛催化剂对C5^C11烃选择性的影响,并对费托合成一步法制汽油馏分烃催化剂的未来发展方向进行了展望。     

Kinetics of Fischer-Tropsch selectivity

The kinetic model of Fischer-Tropsch chain growth as a non-trivial surface polymerization is developed and applied to discuss olefin/paraffin selectivity. The probability of the olefin chemidesorption-reaction, which controls primary olefin selectivity, is derived from experimental data as a function of temperature and total pressure. Secondary olefin hydrogenation and olefin double bond shift are identified in the system as interrelated reactions.