气和煤合成甲醇的原料路线探讨

介绍气煤联产甲醇氢碳互补的工艺原理,比较天然气、煤和气煤联产甲醇的工艺流程、原料消耗、煤气变换率、CO2排放、动力消耗、投资和经济性,指出气煤联产能起到很好的氢碳互补作用,可使水煤气的变换率为最低,气煤联产无论是在原料消耗、动力消耗、CO2排放,还是在投资和经济性上均有一定的优势,是一种较优的甲醇合成原料路线.     

气和煤生产乙二醇合成气的原料路线选择探讨

介绍天然气转化和气煤联产氢碳互补制乙二醇合成气的工艺原理。对天然气部分氧化和气煤联产乙二醇合成气的工艺流程、原料消耗、CO2排放、动力消耗、投资、经济性进行比较。提出气煤联产和天然气部分氧化都是可行的乙二醇合成气生产路线。气煤联产有氢碳互补作用,水煤气无需变换,天然气消耗和氧耗低;天然气部分氧化流程简单、投资省、CO2排放少。经济比较,两种原料路线相差不大。     

轻烃三一段纯氧转化制甲醇合成气的自然增碳研究

为达到甲醇合成的化学当量比,采用三一段纯氧自热转化工艺,即原料气分3路进行换热蒸汽转化、外热蒸汽转化和直入二段炉的蒸汽转化串纯氧自热转化方法,实现自然增碳的目的。对比了天然气制甲醇一段法与三一段纯氧转化法工艺的基本原理和工艺流程;分析了国外天然气二段转化合成甲醇的主要技术参数;从工艺特征、转化流程、设备组合等方面论述了三一段纯氧转化制甲醇合成气的设计技术、消耗指标、投资及成本。结果表明,按甲醇售价2 500元/t计,投产后约2年即可收回投资。     

煤制甲醇和合成氨废气作为天然气生产甲醇补加CO2源

该公司30万t/a以天然气为原料生产甲醇产品的过程中,产生过剩的氢随弛放气排放,另一处装置20万t/a煤制甲醇和10万t/a合成氨排放二氧化碳,造成资源浪费.通过技术改造,将原先作为废气排放的二氧化碳作为甲醇生产装置的补充碳源,该装置由蒸汽转化工艺改造为蒸汽转化前补碳工艺,从而大幅度降低天然气消耗和生产成本.在提高甲醇产品市场竞争力的同时,实现CO2减排.     

煤制甲醇和合成氨废气作为天然气生产甲醇补加CO_2源

该公司30万t/a以天然气为原料生产甲醇产品的过程中,产生过剩的氢随弛放气排放,另一处装置20万t/a煤制甲醇和10万t/a合成氨排放二氧化碳,造成资源浪费。通过技术改造,将原先作为废气排放的二氧化碳作为甲醇生产装置的补充碳源,该装置由蒸汽转化工艺改造为蒸汽转化前补碳工艺,从而大幅度降低天然气消耗和生产成本。在提高甲醇产品市场竞争力的同时,实现CO2减排。     

中海石油天野化工甲醇合成塔及触媒运行控制

1装置介绍 中海石油天野化工股份有限公司油改气联产甲醇,是五环科技股份有限公司总承包设计的一套以天然气为原料,年产200kt甲醇的生产装置。主要工艺：一段蒸汽转化、操作压力2．85MPa、炉前补碳;低压合成甲醇、操作压力8．0MPa;3＋1塔精馏生产精甲醇;膜分离弛放气氢回收;MEA烟道气CO2回收工艺流程,CO2回收工序的碳源为一段转化炉的烟道气,回收的CO2气体为甲醇装置和尿素装置补充CO2气体,项目于2005年12月11日一次投料成功。     

壳牌煤气化制甲醇之变换装置工艺流程的优化设计

介绍了壳牌煤气化制甲醇的变换工艺流程和操作参数;针对现有工艺提出了三段变换和二段变换2个优化改进方案;从流程特点、蒸汽消耗、建设投资和催化剂装填等方面,对比了现有流程和2个改进流程的优缺点。结果表明,CO变换装置采用二段变换流程优于采用三段变换流程。     

自热式纯氧二段转化工艺在甲醇装置技改中应用

甲醇是重要的基础化工产品之一,在国民经济中占有重要地位。天然气自热式纯氧二段转化已是一种成熟的生产工艺。结合企业现有生产工艺,采用自热式纯氧天然气二段转化工艺来改造,相比原一段转化工艺,天然气消耗降低300 m3/t甲醇,同时减少了一段炉烟气排放,降低甲醇的生产成本、适应环境发展要求,实现甲醇生产节能减排及可持续发展。     

饱和塔增湿技术在焦炉煤气制甲醇中的应用

将合成氨变换工序的饱和塔增湿技术引入焦炉煤气制甲醇的生产工艺中,利用转化工艺冷凝液回收转化加热炉对流段的烟气余量,为焦炉煤气加湿,减少了工艺蒸汽消耗、新水消耗和废水的排放。     

合成氨生产“十五”重点推广技术

大型合成氨（气头）：一段炉烟气实施余热回收，降低烟道气排放温度；采用新型催化剂降低进料H2O／C，降低工艺蒸汽消耗量；采用“温和转化”或“换热转化”等节能型工艺设计，提高转化效率。变换工序采用低水碳比高活性的催化剂，提高CO变换率，降低蒸汽消耗。采用新型合成塔内件配以小颗粒、高活性催化剂和合成回路改造。     

Kinetic and CFD Modeling of Exhaust Gas Reforming of Natural Gas in a Catalytic Fixed-Bed Reactor for Spark Ignition Engines

Fuel reforming is an attractive method for performance enhancement of internal combustion engines fueled by natural gas, since the syngas can be generated inline from the reforming process. In this study, 1D and 2D steady-state modeling of exhaust gas reforming of natural gas in a catalytic fixed-bed reactor were conducted under different conditions. With increasing engine speed, methane conversion and hydrogen production increased. Similarly, increasing the fraction of recirculated exhaust gas resulted in higher consumption of methane and generation of H₂ and CO. Steam addition enhanced methane conversion. However, when the amount of steam exceeded that of methane, less hydrogen was produced. Increasing the wall temperature increased the methane conversion and reduced the H₂/CO ratio.     

制氢技术现状及展望

矿物燃料制氢是主要的制氢方法，其中以天然气蒸汽转化制氢的成本最低。重油部分氧化和煤气化曾经是制氢的重要方法，由于生产成本较高其发展有所减缓。这三种制氢过程制得合成气后还要经过变换完成进一步制氢，最后脱除CO2得到较纯的氢气，过程复杂。随着燃料电池的商业化进程的日益加快，低成本的、不含或少含CO的制氢技术受到广泛关注，其中铁蒸汽法和甲烷催化裂解法制得的氢气不含CO和CO2，过程得到简化。显然，矿物燃料制氢要向大气排放大量的温室气体，对环境不利。水电解制氢是较理想的制氢方法，不产生温室气体，但生产成本较高。因此水电解制氢适合电力资源如水电、风能、地热能、潮汐能以及核能比较丰富的地区。其他制氢技术如热化学制氢、太阳能制氢、生物质制氢以及等离子体制氢也在开发之中，相信是矿物燃料制氢与水电解制氢的有效补充。     

CFD analysis of water gas shift membrane reactor

Fuel cell based modular power generation can be achieved by miniaturization and process intensification of equipments in the process. Fuel cells require hydrogen rich gas which can be generated through reforming and water gas shift reaction. The water gas shift reactor being kinetically limited occupies more volume to achieve the required CO conversion. A membrane reactor integrates the reaction and hydrogen separation stages and hence reduces the volume requirement. Computational Fluid Dynamics offers virtual prototyping of the reactor and thus helps in design, optimization and scale up of reactors. In this study customized User Defined Functions (UDFs) were developed to analyze the performance of low temperature water gas shift membrane reactor. The models were validated using literature data for the parameters – synthesis gas compositions, time factor, sweep flow rate and steam to CO ratio. The effect of all these parameters on the reactor was analyzed for CO conversion, H₂ recovery, DaPe, concentration polarization, concentration profiles and conversion index. The simulations have showed that the UDFs developed were capable of simulating the membrane reactor and this can be used for the design and optimization of the membrane reactor for any process conditions.     

Partial oxidation reforming of biomass fuel gas over nickel-based monolithic catalyst with naphthalene as model compound

With naphthalene as biomass tar model compound, partial oxidation reforming (with addition of O₂) and dry reforming of biomass fuel gas were investigated over nickel-based monoliths at the same conditions. The results showed that both processes had excellent performance in upgrading biomass raw fuel gas. Above 99% of naphthalene was converted into synthesis gases (H₂+CO). About 2.8 wt% of coke deposition was detected on the catalyst surface for dry reforming process at 750 °C during 108 h lifetime test. However, no coke deposition was detected for partial oxidation reforming process, which indicated that addition of O₂ can effectively prohibit the coke formation. O₂ can also increase the CH₄ conversion and H₂/CO ratio of the producer gas. The average conversion of CH₄ in dry and partial oxidation reforming process was 92% and 95%, respectively. The average H₂/CO ratio increased from 0.95 to 1.1 with the addition of O₂, which was suitable to be used as synthesis gas for dimethyl ether (DME) synthesis.     

天然气制甲醇的物料关系分析

以转化气中一氧化碳、二氧化碳含量为变量建立天然气转化的摩尔反应方程,分析天然气蒸汽转化及纯氧转化工艺的转化气量/天然气量、蒸汽分解率、转化气中氢含量及甲烷含量与转化气中一氧化碳、二氧化碳含量之间的关系。     

Thermodynamics of Hydrogen Generation from Methane for Domestic Polymer Electrolyte Fuel Cell Systems

Low temperature fuel cells such as the Polymer Electrolyte Fuel Cell (PEFC) are preferably used for domestic applications because of their moderate operating conditions. Using the existing distribution system, natural gas is used as a source for a hydrogen rich gas to power this fuel cell type. The high requirements on the fuel gas quality as well as high conversion efficiencies for the small local gas processing units are critical aspects in the evaluation of decentralized fuel cell systems. In the present paper, three typical gas processing methods are evaluated for the supply of a hydrogen rich gas for PEFCs: steam reforming, partial oxidation, and autothermic conversion. All three processes are studied in detail by varying the relevant process parameters: temperature, pressure, steam to fuel ratio, and oxygen to fuel ratio. The results are graphically displayed in numerous nomograms. With the help of these graphs, regions of stable operation and the sensitivity to the operational parameters are discussed. For all three gas processing methods, the graphs generated display methane conversion, the hydrogen yield, and the yields of unwanted components, i.e., carbon monoxide and solid carbon. Although only steady‐state operating conditions were simulated, critical modes of operation, which might occur during start‐up or transient operation can easily be identified. For instance, operating conditions where soot is generated have to be avoided under all circumstances. All simulations were done with the Gibb's reactor model of a commercial simulation program. The Gibb's reactor model was found to be a suitable tool, since the simulated results compared well with reported literature data. According to the simulation results, the methane‐steam‐reforming process appears to be favorable for application to PEFCs. Methane conversion and hydrogen yields are highest for this process while the yield of CO is relatively low.     

用于PEMFC的天然气水蒸气制氢系统

针对质子交换膜燃料电池（PEMFC）的应用要求,开发了一个包括天然气水蒸气重整、CO变换和变压吸附净化的制氢工艺过程,并着重对重整反应和变压吸附的操作条件进行了实验研究。考察了温度、空速和水碳比对重整反应的影响,得到适宜的工艺操作条件,实验结果表明：温度650℃、水碳比6、空速42h^-1时,氢气含量为70.21%,甲烷转化率为77.41%;分析了温度、流速对变压吸附脱除CO效果的影响,结果表明：在0.2MPa、40℃和吸附、脱附时间120s的条件下,产品气中CO浓度接近于1×10^-6,经过多次循环后产品气质量稳定,可以连续获得满足80W质子交换膜燃料电池要求的高纯度氢气。     

焦炉气催化部分氧化制甲醇氢碳比优化与CO_2减排

从焦炉气催化部分氧化制甲醇氢碳比的优化谈起,对几种提氢、混兑与直接补碳技术作了介绍,给出了回收CO2成本估算的依据,对转化前后补碳、补碳量等作了论述和说明,得出了调节、优化氢碳比可降低甲醇消耗和生产成本、实现CO2减排,既有经济效益也有社会效益的结论,有条件的企业可结合自身实际选择。     

吸附强化乙醇水重整制氢的工艺条件

采用吸附强化技术强化了乙醇水重整制氢过程。考察了温度、水醇比、液空速对无强化乙醇水重整制氢反应特性的影响,在此基础上研究了吸附强化乙醇水重整制氢反应特性。通过响应面法确定了吸附强化乙醇水重整制氢最优工艺条件为温度422～444 ℃、水醇比10.2～10.8、液空速0.13 h?1,在此条件下的氢产率为3.2 mol/mol,同比提高了51.7%,氢含量为88.91%,同比提高了22.9%,反应温度降低了178 ℃,降低了能耗,控制了CO2排放。