煤制天然气淮南煤气化技术的选择

主要介绍了淮南煤和煤灰的特性,通过煤气化技术比较,选择煤制天然气方案中适合淮南煤的气化技术。     

新疆伊犁地区煤制天然气技术经济分析

分析了新疆伊犁地区的煤炭资源和利用现状,结合国家西气东输二线工程的实施,从政策、技术、规模、厂址选择、资源配套等方面,论述了在伊犁地区开展煤制天然气的可行性,并选择典型煤种和工艺进行技术经济评价,得出在伊犁地区开展煤制天然气的可行性结论并给出合理化建议。     

天然气换热式转化制合成气催化剂的选用

论述了制合成气过程催化剂的选择及重要性,转化催化剂要求有较好的低温活性和抗积炭性能,中变催化剂考虑催化剂本体含硫量,低变催化剂要从活性、热稳定性、堆积密度、还原后体积收缩率、烧失重和自由水含量等方面衡量,甲烷化催化剂的选用要根据设备状况满足工艺要求方面考虑。催化剂的使用寿命既与合理选用催化剂有重要关系,也与工业应用过程中的正确使用和维护有关。     

可用于富氢重整气中CO消除的负载型Ni基甲烷化催化剂研究进展

富氢重整气中微量CO会引起燃料电池中Pt电极的永久性中毒而影响燃料电池的性能,通过CO甲烷化反应是消除富氢重整气中微量CO的有效方法。介绍了近年来在CO甲烷化Ni基催化剂组成、制备方法和催化机理等方面的研究进展。阐述了载体的性质、稀土和贵金属助剂以及制备方法对CO甲烷化Ni基催化剂性能的影响。研究重点通过优化载体、组成和制备方法制备新型Ni基催化剂,使其在低温下对CO甲烷化反应有着很好的催化活性、选择性和稳定性,同时抑制高温下CO2甲烷化反应和逆水煤气反应的发生。     

Studies of the fischer-tropsch synthesis on a cobalt catalyst II. Kinetics of carbon monoxide conversion to methane and to higher hydrocarbons

Six Langmuir-Hinshelwood-Hougen-Watson models have been derived for the kinetics of conversion of carbon monoxide to hydrocarbons in the Fischer-Tropsch synthesis. The models were fitted to experimental data obtained in an internal recycle reactor over a wide range of operating conditions. Two models, one based on the hydrogenation of surface carbon and the other on a hydrogen-assisted dissociation of carbon monoxide as rate limiting steps were both able to provide a satisfactory fit to the experimental rate data. A general model was also developed for the rate of methanation in the presence of higher hydrocarbons. The same two rate limiting assumptions as those used in formulating the rate of total CO conversion are used in these models. The two models were fitted to experimental data for methane formation. It was the model assuming CH formation as rate limiting that showed the best fit for both CO conversion for CH₄ formation.     

稀土改性镍催化剂对CO2甲烷化反应的影响

以稀土为助剂 ,金属镍为活性组份 ,研究了不同稀土对镍催化剂的改性作用 ,同时用活性比表面、H2 -TPD、CO2 - TPD及 XPS等方法对催化剂进行了表征。结果表明 ,稀土对镍催化剂的 CO2 甲烷化活性有明显的促进作用 ,其中以稀土 Sm的改善效果最好 ;海泡石和 Sm既能增大镍催化剂的活性比表面积 ,又能提高 H2 和 CO2 的吸附量 ,同时降低反应的活化能 ,增大镍上的电子云密度。     

The influence of Metal Dusting on gas reactions

Gas composition analysis measurements have been performed in the outlet gas stream of a laboratory metal dusting test furnace in order to study the influence of metal dusting on gas reactions. This analysis has shown that carbon deposition is associated with metal dusting, i.e. the material most severely attacked by metal dusting, catalyses the formation of carbon to the largest extent. Also, metal dusting has not been seen to influence the methanation reactions. A kinetic model has been used to interpret the obtained data with respect to the catalytic activity of several high temperature materials showing that the catalytic activity of the material can vary by orders of magnitude for different reactions.     

The influence of CO,CO2 and H2O on selective CO methanation over Ni(Cl)/CeO2 catalyst: On the way to formic acid derived CO-free hydrogen

For the first time the influence of CO, CO₂ and H₂O content on the performance of chlorinated NiCeO₂ catalyst in selective or preferential CO methanation was studied systematically. It was shown that the rate of CO methanation over Ni(Cl)/CeO₂ increases with the increasing H₂ concentration, is independent of CO₂ concentration and decreases with increasing CO and H₂O concentrations; the rate of CO₂ methanation is weakly sensitive to H₂ and CO₂ concentrations and decreases with increasing CO and H₂O concentrations. High catalyst selectivity was attributed to Ni surface blockage by strongly adsorbed CO molecules and ceria surface blockage by Cl, which both inhibit CO₂ hydrogenation.For the first time, selective CO methanation over Ni(Cl)/CeO₂ was studied for deep CO removal from formic acid derived hydrogen-rich gases characterized by high CO₂ (40–50 vol%), low CO (30–1000 ppm) content and trace amounts of water. Composite Ni(Cl)/CeO₂-η-Al₂O₃/FeCrAl wire mesh catalyst was demonstrated to be effective for this process at temperatures of 180–220°С, selectivity 30–70%, WHSV up to 200 L (STP)/(g∙h). The catalyst provides high process productivity, low pressure drop, uniform temperature distribution, and appears highly promising for the development of a compact CO cleanup reactor. Selective CO methanation was concluded to be a convenient way to CO-free hydrogen produced by formic acid decomposition.     

电转气地质储能技术的经济性分析

电转气(power-to-gas)是一项将电能转化为高能量密度可燃气体的化学储能技术,该技术与地质储能相结合,有望满足未来大容量储能需求,并成为未来有效储能技术选择之一.电转气地质储能技术中涉及电离制氢、甲烷化、二氧化碳(CO2)地质储存、人工合成甲烷(CH4)地质储存4个阶段.由于电转气地质储能技术发展处于初步阶段,...     

焙烧条件对镍基甲烷化催化剂性能的影响

考察了焙烧条件对工业甲烷合成催化剂Ni-MgO-Al2O3的性能的影响,采用X射线衍射、低温氮物理吸附、程序升温还原、CO脉冲吸附等手段对反应后的催化剂进行了表征。结果表明,随着焙烧温度的升高和焙烧时间的延长,催化剂活性金属组分分散效果更好,与载体的结合作用更强,催化剂还原的耗氢量变小。焙烧后有MgAl2O4和NiAl2O4等晶相结构形成,加强了催化剂的机械强度,同时提高了催化剂热稳定性能。在温度750℃、压力2 MPa、空速8 000h-1条件下,950℃焙烧3h的催化剂的活性最好。