生物质合成甲醇的热力学性质研究

采用热化学方法,将玉米秸秆裂解为生物质燃气,制备出甲醇合成气;在C301铜基催化剂的作用下,在直流流动等温积分反应器中,对玉米秸秆合成气催化合成甲醇进行了试验研究.运用SHBWR状态方程,计算了加压下秸秆合成气合成甲醇反应体系的密度及状态方程参数;在一定温度和压力条件下,计算了不同组成秸秆合成气合成甲醇反应体系的总反应热△HT P、平衡常数Kf1、Kf2、Kp1、Kp2及平衡体系各组分的浓度,为生物质(秸秆)气催化合成甲醇工业设备的设计提供了基础研究数据.     

秸秆合成气催化合成甲醇催化剂优化试验研究

生物质能是一种可再生能源,为了研究秸秆类生物质转化为燃料甲醇以有效地利用生物质能,采用热化学方法在下吸式固定床气化炉中生产低热值燃气,对该燃气进行脱硫、脱氧、焦油催化分解、纯化、配氢等优化试验,制备出秸秆合成气。在直流流动等温积分反应器中进行了催化合成甲醇的试验,在235℃和5MPa条件下进行了催化剂种类及粒度对合成甲醇的影响试验。试验结果表明:合成甲醇的适宜催化剂型号为C301,最优化颗粒粒度为0.833mm×0.351mm,该研究为生物质(秸秆)气催化合成甲醇的深入研究提供了基础数据。     

秸秆类生物质催化合成甲醇的实验研究

为了将农业废弃物转变为燃料甲醇，对玉米秸秆燃气进行合成气优化实验，在5MPa压力下，采用等温积分反应器和国产C301铜基催化剂，对合成气进行催化合成甲醇的实验研究。     

生物质气一步法合成二甲醚化学平衡分析

对生物质基合成气合成二甲醚反应体系进行热力学参数计算.选取CO、CO2加氢合成甲醇及甲醇脱水生成二甲醚为独立反应,CO、CO2、二甲醚为关键组分,提出了合成气合成二甲醚的计算模型.讨论了温度、压力对生物质气合成二甲醚化学平衡的影响.结果表明:CO平衡转化率、DME平衡收率随温度的升高而下降;随压力升高,CO平衡转化率、DME平衡收率增加.     

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。     

生物质合成气合成甲醇

在高压微型反应装置上进行了生物质合成气合成甲醇的实验研究。利用组成为V(H2)/V(CO)/V(CO2)/V (N2)=50/25/20/5的富CO2原料气考察了不同温度、压力和空速条件下甲醇的时空产率、甲醇和水的选择性等指 标。结果表明,在所考察的范围内,温度、压力和空速对甲醇的产率和选择性都有影响。在反应压力为4．6MPa, 空速为7000h-1时,时空产率的最大值为0．69g/(mL·h),甲醇的选择性范围为93％-97．2％。和富CO的原料气 相比,利用富CO2的生物质合成气合成甲醇,甲醇的时空产率和选择性都有所下降,时空产率下降的幅度在 10％-30％之间,选择性的下降幅度在2％-8％之间。通过控制适宜的操作条件,可降低甲醇的产率和选择性 的下降幅度。     

页岩气自热转化等压合成60×10~4t/a甲醇工艺设计

我国页岩气资源丰富,是替代石油生产乙丙烯的原料。美国页岩气为原料生产乙烯的成本仅为石油制乙烯的38%。页岩气生产合成气制甲醇,再生产乙丙烯的生产过程采用组合生产工艺,包括页岩气纯氧自热转化制合成气,合成气在等压下直接合成甲醇,省去了合成气压缩机,副产高压蒸汽作空分空压机动力平衡能源,不需燃料加热,无燃气CO2排放。页岩气自热转化制得的合成气在H2-CO/CO+CO2=2.1~2.2,压力5MPa下合成甲醇,甲醇合成采用气冷和水冷串联合成,提高了合成转化率,合成甲醇浓度很高,省去了甲醇精馏。甲醇制烯烃采用甲醇脱水制烯烃(MTO)工艺,MTO工艺原料需求低,原料消耗少,烯烃收率高,乙烯、丙烯可调性大,产品分离简单方便,材质要求低。由甲醇催化制得的烯烃气体不含有机硫化物和乙炔,省去了十分复杂的烯烃分离工艺,所以甲醇制乙烯比石油制乙烯具有较大的竞争力,是今后乙烯工艺技术的发展方向。设计的4.8×108m3页岩气制60×104t/a甲醇,再生产24×104t/a乙丙烯组合工艺总投资约为26亿元,年利税9.94亿元,投产后约3年即可回收投资。     

焦炉气加氢净化工艺及催化剂问世

以煤制合成气合成甲醇在我国发展迅速，为了降低甲醇生产成本及寻找更廉价的原料，现在人们又把目光投向了焦炉气，而焦炉气制甲醇技术的关键是净化处理及高效转化。近日从西北化工研究院获悉，该院在加氢脱硫系列催化剂研究的基础上，开发成功焦炉气加氢净化工艺及催化剂，使焦炉气制甲醇合成气实现了工业化。     

合成气_甲醇掺烧火焰研究

对合成气-甲醇掺烧火焰进行了实验研究及数值分析.实验观测了火焰形态,测量了火焰温度及烟气中NOx污染物的浓度.实验表明:相同功率条件下,相比于合成气火焰,合成气-甲醇掺烧火焰尺寸略显细长、高温区温度略低、烟气中NOx排放较少.通过数值计算分析指出,合成气-甲醇掺烧火焰尺寸变长缘于火焰中甲醇未能及时消耗完,火焰温度降低缘于甲醇火焰温度较低,烟气中NOx排放减少缘于火焰中加入甲醇有利于抑制热力型NO及中间型NO的生成.     

采用串联液相甲醇合成的多联产系统变负荷性能的分析

建立了多联产系统部件的变工况模型,分析了串联结构的甲醇、电力联产系统的变负荷性能.系统采用液相甲醇合成工艺,并针对该工艺可以直接使用富CO合成气的特点,根据是否包括合成气水煤气变换工艺,设计了变换系统和不变换系统.对这2个系统在设计工况和部分电力负荷工况时的性能进行了计算和比较,特别对变换系统的变负荷性能进行了较详细的分析.结果表明:串联多联产系统可以通过调节甲醇合成单元的循环比实现不改变气化单元的运行工况而降低电力负荷.     

Process simulation and optimization of methanol production coupled to tri-reforming process

Tri-reforming, as a new approach for the treatment of CO₂ in flue stack gases, has been studied in this work. To determine the optimum operating conditions for the production of syngas with target ratio and maximum CO₂ conversion, the effects of temperature (400–1200 °C), CH₄/Flue gas ratio (0.4–1.0) and pressure (1–5 atm), on the compositions of syngas were investigated. Also, the methanol production from syngas has been rigorously simulated. An optimum heat exchange network was obtained with the objective of minimizing both utility and capital costs, which were calculated by General Algebraic Modeling system (GAMS). Furthermore, an economic analysis was carried out to substantiate the potential profits based on the conceptual results from heat integration. Results showed that the tri-reforming process, when integrated with methanol synthesis, is an economical approach for the treatment and utilization of CO₂ in flue gases.     

Thermodynamic analysis of syngas production from biodiesel via chemical looping reforming

In this study, thermodynamic analysis of the syngas production using biodiesel derived from waste cooking oil is studied based on the chemical looping reforming (CLR) process. The NiO is used as the oxygen carrier to carry out the thermodynamic analysis. Syngas with various H₂/CO ratios can be obtained by chemical looping dry reforming (CL-DR) or steam reforming (CL-SR). It is found that the syngas obtained from CL-DR is suitable for long-chain carbon fuel synthesis while syngas obtained from CL-SR is suitable for methanol synthesis. The carbon-free syngas production can be obtained when reforming temperature is higher than 700 °C for all processes. To convert the carbon resulted from biodiesel coking and operate the CLR with a lower oxygen carrier flow rate, a carbon reactor is introduced between the air and fuel reactors for removing the carbon using H₂O or CO₂ as the oxidizing agent. Because of the endothermic nature of both Boudouard and water-gas reactions, the carbon conversion in the carbon reactor increases with increased reaction temperature. High purity H₂ or CO yield can be obtained when the carbon reactor is operated with high reaction temperature and oxidizing agent flow.     

玉米秸秆燃烧过程及燃烧动力学分析

采用TG-DTA-DTG热分析联用技术对玉米秸秆在不同升温速率下进行了燃烧实验.考察了着火温度、燃烧速率最大时温度、燃尽温度等燃烧特征参数.根据对不同升温速率下玉米秸秆燃烧过程的分析,用双组分分阶段反应模型能够很好的描述玉米秸秆的燃烧过程.建立了玉米秸秆反应动力学方程,得到了在不同温度区间的燃烧动力学方程和表观活化能、频率因子等燃烧动力学参数,并提出了相应的燃烧机理.     

Techno-economic-environmental evaluation of a combined tri and dry reforming of methane for methanol synthesis with a high efficiency CO2 utilization

Production of methanol, as a green energy, from syngas is coming into focus. However, natural gas based methanol plants, which are used steam reforming of methane for syngas production, have a high CO₂ emission resulting in the global warming. In this study, a novel process for methanol synthesis is proposed to reduce CO₂ emission. In this regard, natural gas and flue gas are fed to a parallel-series system with tri and dry reforming of methane for syngas production with the optimized stoichiometric number. Then, the produced syngas is converted to methanol in a reactor. Finally, the produced methanol is purified by two distillation towers. The proposed method is compared to a referenced method in the view of technological, economic and environmental metrics. The techno-economic-environmental analysis of the processes reveals that not only the proposed method, as compared to the referenced one, increases CO₂ conversion from 20.93% to 99.22%, but also it is more economical and environmentally friendly. In addition, the global warming potential of the proposed method is almost 60% lower than that for the referenced method due to the lower CO₂ emission. Therefore, the proposed method can save above MUS$ 8 a year by CO₂ capture.     

油页岩干馏残渣与玉米秸秆混烧特性

利用热重分析仪对汪清油页岩干馏残渣、玉米秸秆及二者不同比例的混合物进行了不同升温速率下的燃烧特性实验,得到了燃烧特性曲线并求解了燃烧特性参数.研究结果表明,玉米秸秆的燃烧特性明显优于油页岩干馏残渣,油页岩干馏残渣中掺入玉米秸秆后,着火温度、燃尽温度提前,综合燃烧特性得到改善;混合物的综合燃烧特性指数随升温速率的升高而增...     

Process design and techno-economic analysis of dual hydrogen and methanol production from plastics using energy integrated system

This study has been dedicated towards the conversion of plastics to methanol and hydrogen. The base design (case 1) represents the conventional design for producing syngas via steam gasification of waste plastics followed by CO₂ and H₂S removal. The syngas then processed in the methanol synthesis reactor to produce methanol, whereas, the remaining unconverted gases are processed in water gas shift reactors to produce hydrogen. On the other hand, an alternative design (case 2) has been also developed with an aim to increase the H₂ and methanol production, which integrates the plastic gasification and the methane reforming units to utilize the high energy stream from gasification unit to heat up the feed stream of reforming unit. Both the cases have been techno-economically compared to evaluate the process feasibility. The comparative analysis revealed that case 2 outperforms the case 1 in terms of both process efficiency and economics.     

Molecular composition of soluble fraction from depolymerized cornstalk powder in supercritical methanol and ethanol

Cornstalk was depolymerized in supercritical methanol and ethanol, respectively. The depolymerization products were analyzed with FTIR and GC/MS. The results show that the products can be classified into methyl esters and dimethyl diesters, ethyl esters and diethyl phthalate, hydroxybenzenes and dihydroxybenzenes, ketones, methoxybenzene to trimethyoxybenzenes, hydrocarbons, nitrogen-containing organic compounds and other compounds. Most of the products are oxygen-containing species. Palmitate and octadec-9-enoate are the two most abundant products both with supercritical methanol and with supercritical ethanol. The fact that the cornstalk depolymerization in different solvents afforded many different products suggests that the two solvents played different roles in the cornstalk depolymerization.