气相色谱法测定合成气制烯烃水相产物中低碳醇、醛、酮、酸化合物

采用气相色谱法建立了合成气制烯烃(SGTO)水相产物中低碳醇、醛、酮、酸的测定方法,对分离条件进行优化,使用标准试样测定了线性范围和工作曲线,考察了方法的精密度和准确度,并采用该方法对SGTO实际水相产物中低碳醇、醛、酮、酸进行了测定。实验结果表明,在一定质量浓度范围内,低碳醇、醛、酮、酸各组分均呈现良好的线性关系,相关系数大于0.99。标样的回收率在93.4%~109.8%之间,6次重复测定的相对标准偏差小于3.9%。SGTO实际水相产物中低碳(C1~6)醇、醛、酮、酸的分析结果表明,SGTO实际水相产物中低碳(C1~6)醇、醛、酮、酸的总含量(w)在1.5%~3.0%之间;其中,乙醇的含量最高,丙酮其次。     

热等离子体重整甲烷和二氧化碳制合成气的热力学研究

常压下利用4kW的直流电弧等离子体装置,进行了甲烷和二氧化碳在氮气等离子体射流作用下重整制备合成气的实验研究。利用氮气作为放电气体产生等离子射流,甲烷和二氧化碳作为反应气体垂直送入此高温射流中,考察了甲烷与二氧化碳配比、进气流量和输入功率对原料转化率、化学能效及热值产率的影响。结果表明:热等离子体重整甲烷和二氧化碳制合成气具有处理量大、甲烷和二氧化碳转化率高、化学能效和热值产率高的特点。     

有效气体回收对造气岗位的意义浅议

介绍气量波动、紧张时,工艺方面的补救措施,包括调整变压吸附、提氢岗位指标,改变气柜高度,控制循环氢等手段。     

Steam gasification of bitumen oil in presence of Ni/dolomite catalysts

An important step in developing clean energy and reducing greenhouse gas emissions is the use of clean technologies such as gasification. In this work, we were used a bubbling fluidized bed (BFB) to convert the bitumen oil into a clean syngas in presence of three kinds of Ni/dolomite catalysts. While all three catalysts were acceptable in the process of tar elimination, but DN-22 was more successful in eliminating tar than the other two samples, which might be due to the higher amount of CaO in the composition DN-22. With increase in Ni, the amount of eliminated tars in the tar cracking process was also increased due to the delay in the deactivation of the dolomite catalyst.     

Dynamic Matrix Control of a Bubble‐Column Reactor for Microbial Synthesis Gas Fermentation

A spatiotemporal metabolic model of a representative syngas bubble‐column reactor was applied to design and evaluate dynamic matrix control (DMC) schemes for regulation of the desired by‐product ethanol and the undesired by‐product acetate. This model was used to develop linear step response models for controller design and also served as the process in closed‐loop simulations. A 2 × 2 DMC scheme with manipulation of the liquid and gas feed flows to the column provided a superior performance to proportional integral (PI) control due to slow process dynamics combining the multivariable and constrained nature of the control problem. Ethanol concentration control for large disturbances was further improved by adding the flow of a pure hydrogen stream as a third manipulated variable. The advantages of DMC for syngas bubble‐column reactor control are demonstrated and a design strategy for future industrial applications is provided.     

The Effect of Additives on Cu/HZSM-5 Catalyst for DME Synthesis

The addition of ZnO or ZrO₂ into CuO/HZSM-5 was investigated for DME synthesis from syngas by using the reactive frontal chromatography method, TPR and in situ TPR. These promoters enhanced the catalytic activity of Cu/HZSM-5 and promotion with ZnO and ZrO₂ produced a maximum activity, which could be explained by the improvement of the dispersion of Cu and the promotion of CuO reduction. The Cu⁺ species existing during the reaction have been detected, based on which a Cu⁰ Cu⁺¹ redox cycle model was put forward.     

Partial Oxidation of Methane to Syngas over Monolithic Ni/γ-Al2O3 Catalyst——Effects of Rare Earths and Other Basic Promoters

A series of monolithic Ni/γ-Al2O3 catalysts with and without basic promoters (Na, Sr, La, Ce) were prepared. Partial oxidation of methane (POM) to syngas was carried out in a continuous-flow, fixed-bed reactor. The influences of reaction conditions, including temperature, CH4/O2 ratio and space velocity, on the performance of the catalyst were investigated. The results show that at a high space velocity of 1×105 h-1, optimal CH4 conversion can be obtained. Effects of promoters such as Na, Sr, Ce, La were also investigated, and the catalyst samples were characterized by means of temperature-programmed reduction and XRD techniques. XRD suggests that the addition of promoters has no influence on the crystal structure of Ni/γ-Al2O3 catalyst. The results show that the addition of a small amount of promoters improves the reducibility and activity of the catalyst. The side reaction CH4 2 O2→CO2 H2O, is fully restrained and 100% H2 selectivity is achieved when Ce and La are used as promoters, respectively.     

Carbon Dioxide Reforming of Methane Over Nanocomposite Ni/ZrO2 Catalysts

A systematic study of the size effect of zirconia nanocrystals on nickel-catalyzed reforming of methane with CO₂ shows that extremely stable Ni/ZrO₂ catalysts are obtainable by hydrogen reduction of impregnated nickel nitrate on zirconia particles with sizes less than 25 nm. The same preparation method with larger particles of zirconia results in catalyst samples that deactivate rapidly in the reforming reaction. Comprehensive characterization with XRD, TPR/TPD, and TEM shows that the stable Ni/ZrO₂ catalysts are better described as nanocomposites of size comparable to Ni metal (9-15 nm) and zirconia (7-25 nm) nanoparticles. The high percentage of the Ni-zirconia boundary or perimeter in the nanocomposite catalysts is believed to be crucial for the extremely stable catalytic activity.     

Infrared studies of reaction of ethylene with syngas on Ni/SiO2

Ni/SiO₂, a methanation catalyst, has been shown to exhibit CO insertion activity. In situ infrared studies of CO/H₂ and C₂H₄/CO/H₂ reactions on Ni/SiO₂ show that carbonylation of Ni/SiO₂ to Ni(CO)₄ leads to an inhibition of methanation in CO hydrogenation but an enhancement of formation of propionaldehyde in the C₂H₄/CO/H₂ reaction.     

甲醇合成气的制取与等压合成创新工艺的发展前景

介绍了甲醇合成工艺的进展，指出现代工业生产采用压力为5MPa的高压造气等压合成甲醇工艺，分析了合成气对甲醇合成的影响。重点阐述了轻烃转化制甲醇合成气的创新工艺——三一段（即外热蒸汽转化、换热转化和自热转化）纯氧转化工艺的特点、原理、工艺流程及主要物耗能耗指标，并与传统工艺进行了对比。举例说明了高压合成气等压合成甲醇技术的推广应用。最后对我国煤炭能源化工综合发展的产品开发和规划框架提出了建议。