生物质间接液化一步法合成燃料二甲醚

结合合成气制备液体燃料二甲醚的技术特点，对生物质在不同气化介质中的气化工艺以及气体组分分布进行了分析，对生物质合成气的自有特点和组分调整等重要制备过程进行了分析探讨，参考煤气化制备二甲醚的工艺过程，提出了生物质间接液化一步法合成液体燃料二甲醚的工艺路线设想。     

信息与动态

生物法二甲醚合成技术通过验收中国科学院广州能源研究所承担的广东省国际科技合作项目"生物质气化合成二甲醚(DME)技术的合作研究与应用示范"通过验收。该项目于2010年正式启动,在生物质流化床气化技术、粗合成气催化重整净化与组分调变技术与装置、生物合成气的二甲醚合成工艺与催化剂等方     

生物质合成气一步法合成二甲醚的研究

用共沉淀沉积法制备了生物质合成气直接合成二甲醚(DME)的催化剂,考察了固定床中温度、压力、空速等工艺条件对二甲醚合成性能的影响,同时基于Gibbs自由能最小法对合成DIME反应的化学平衡进行模拟计算,并与实际测试结果相比较.结果表明,模拟结果与测试结果吻合较好.     

生物质热化学转化合成二甲醚

在鼓泡流化床反应器内，采用空气-水蒸汽气化松木粉制备了富氢燃气，在下游的固定床重整反应器内，通过添加沼气重整富氢燃气，调变化学当量比，制备了含氮的生物质合成气. 在Cu-Zn-Al/HZSM-5催化剂上，对生物质合成气一步法合成二甲醚进行了实验研究. 在280℃, 4 MPa, 1000~4000 h-1的条件下，CO的单程转化率达到67%，单位质量催化剂的最大二甲醚时空收率0.358 g/(g×h) [DME/(催化剂×h)]；通过添加沼气重整，90%以上的生物质碳转化为合成气，二甲醚的最大产量为0.244 kg/kg (DME/生物质).     

新型能源二甲醚合成催化剂和工艺发展综述

二甲醚(DME)作为一种多用途的清洁环保能源,因其作为新型清洁燃料在替代柴油或液化气方面的广阔的市场前景,近年来受到了越来越多的关注。二甲醚的合成主要有甲醇脱水(两步法)、合成气直接合成(一步法)和二氧化碳加氢合成三种途径,而目前已工业化的工艺包括甲醇气相脱水、合成气直接合成和二甲醚/甲醇联产三种工艺。本文对二甲醚合成催化剂及工艺的最新发展进行了综述。     

二甲醚等技术简介

1 Topse公司专有技术及产品 1.1 二甲醚技术 二甲醚（DME）工业生产技术有甲醇脱水和合成气直接合成两种，通过合成气一步法生产二甲醚技术进展很快。所谓一步法，即将合成甲醇和甲醇脱水两个反应组合在一个反应器内完成，具有流程短、能耗低等优点，而且可得到较高的单程转化率。合成气一步法工艺包含下面二三个工艺流程。     

生物质合成气合成二甲醚的研究

在加压固定床反应装置上进行了生物质合成气合成二甲醚(DME)的研究.采用机械混合法制备二甲醚合成双功能催化剂.考察了组成为V(H_2):V(CO):V(CO_2):V(CH_4)=52:24:23:1的生物质合成气在不同反应温度、空速、压力下对合成二甲醚反应的影响.同时进行了102 h的催化剂的稳定性实验.结果表明,在260-300℃范围内,随反应温度的升高,CO转化率和二甲醚的选择性均先增大后减小;随反应压力的升高,CO转化率和二甲醚选择性都随之升高;原料气中高浓度的CO_2可导致铜基催化剂较快的失活.     

HZSM-5硅铝比对生物质合成气合成二甲醚的影响

以不同硅铝比的HZSM-5分子筛为甲醇脱水活性组分,采用共沉淀沉积法制备合成二甲醚的双功能催化剂Cu-ZnO-Al2O3/HZSM-5,在加压固定床反应装置上进行了生物质合成气合成二甲醚的研究。考察了不同硅铝比的HZSM-5对生物质合成气合成二甲醚的影响。结果表明,随着硅铝比的增加,催化剂的酸性降低,使得CO的转化率降低。当硅铝比为38时,双功能催化剂具有较好的活性和选择性。     

合成气一步法合成二甲醚研究

结合国内外二甲醚研究现状,从合成气一步法合成二甲醚的分类、工艺、热力学、动力学、催化剂等方面进行了阐述,并对合成气一步法制取二甲醚进行了技术评价。     

合成气一步法制取二甲醚技术研究进展

二甲醚是一种重要的化工原料和理想的清洁替代能源.由合成气一步法直接制取二甲醚克服了甲醇合成反应的热力学限制,大大提高了合成气的转化率,近年来发展迅猛.对合成气一步法直接制取二甲醚技术的进展进行了综述和展望,包括催化剂及制备方法和工艺.     

二甲醚合成技术研究概况

简要介绍了二甲醚的性质、用途,详细阐述了一步法和两步法制取二甲醚的工艺路线,对各工艺路线的特点、技术研究进展和实际工业应用状况进行了介绍,并提出了采用生物质制取二甲醚的可能性与合适的工艺路线。     

生物质气一步法合成二甲醚双功能催化剂失活研究

概述了生物质气一步法合成二甲醚双功能催化剂的热失活、中毒失活的原因及其解决方案。提出了载体是二甲醚合成催化剂需要突破的重点,将整体式催化剂载体应用二甲醚合成中,不失为一个新的研究方向。     

清洁燃料二甲醚的合成技术

介绍了清洁燃料二甲醚的性质与用途、合成技术、所涉及的催化剂以及合成反应器,并提出了生物质制取二甲醚的可能性.     

二甲醚生产工艺技术进展

对国内外二甲醚的生产工艺,如两步法、一步法、二氧化碳及生物质直接合成二甲醚等进行了评述,认为一步法工艺比较适合我国国情;对国内二甲醚生产技术提出了合理建议.     

Design framework for dimethyl ether (DME) production from coal and biomass-derived syngas via simulation approach

A comprehensive thermodynamic study was conducted to evaluate the comparative efficacy of methanol and dimethyl ether (DME) synthesis using CO₂ rich syngas feed. The first part of our study included assessing the relative performances of the methanol synthesis system, two step DME synthesis system, and one step DME synthesis system in terms of the CO_x conversion and product yield (methanol/DME) based on the Gibbs free energy minimization approach. The wide range of composition of CO₂-enriched syngas feed produced by the coal and biomass gasification was simulated using Aspen Plus and the following evaluation parameters were analyzed for a broad parameter range: reaction temperature (180–280°C), reaction pressure (10–80 bar), stoichiometry number (SN) (0–11), and CO₂/(CO₂ + CO) molar feed ratio (0–1) for isothermal as well as adiabatic conditions. Based on the equilibrium yield, one-step DME synthesis was discovered as the most viable process to utilize the co-gasification derived syngas effectively. In the second part of our study, the overall process efficiency was inspected through the process design of 1 tonnes per day (TPD) DME plant inclusive of heat integration, resulting in significant CO₂ abatement and DME production with high product purity and minimum energy consumption. Consequently, one-step DME production via CO₂-enriched syngas obtained through the coal or biomass gasification process is identified as the leading technology based on energy utilization and CO₂ abatement.     

Dewatering of Biomass Using Liquid Bio Dimethyl Ether

An interesting integrated configuration in a thermochemical conversion biorefinery that is producing dimethyl ether (DME) is to use a small fraction of the BioDME for dewatering of the solid biomass feedstock. Therefore, the use of liquid BioDME was investigated in this study for pressurized dewatering of biomass at room temperature. Water was removed in liquid form from wet sawdust and wet wood chips using liquid DME in a laboratory-scale batch unit. Both the sawdust and the wood chips could be dewatered in a short time (minutes) to a moisture content of 15% (w/w) from an initial content of approximately 55% (w/w). Longer DME treatment times (hours) lowered the moisture content even further down to 8% (w/w), indicating that the transport phenomena in the porous biomass and the solubility of DME in water influence the dewatering characteristics. The DME dewatering performance, 12–22 g DME per g water removed, was similar to literature data on coal dewatering using liquid DME. The present study showed that DME dewatering of the solid biomass feedstock has potential as an energy-efficient dewatering process, especially in an integrated thermochemical conversion biorefinery.     

Co-gasification of woody biomass and coal with air and steam

The co-gasification of woody biomass and coal with air and steam was carried out in order to supply syngas for the synthesis of liquid fuels from the biomass with coal. The experiment was performed using a downdraft fixed bed gasifier at 1173 K. The effect of the feedstock with a varying content of woody biomass and coal on the co-gasification behavior was studied by varying the biomass ratio from 0 to 1; this ratio is the woody biomass content in the total feedstock on a carbon basis. The conversion to gas on a carbon basis increased with an increase in the biomass ratio, whereas the conversions to char and tar decreased. With an increase in the biomass ratio, the H₂ composition decreased and the CO₂ compositions increased. However, the CO composition was independent of the biomass ratio. A low biomass ratio led to the production of a gas favorable for methanol and hydrocarbon fuel synthesis, and a high biomass ratio led to the production of a gas favorable for DME synthesis. The synergy due to the mixture of woody biomass and coal might be observed in the extent of the water–gas shift reaction. The co-gasification conditions in the study provided a cold gas efficiency ranging from 65% to 85%.     

浆态床一步法二甲醚产业化技术开发研究进展

介绍了国内外浆态床一步法二甲醚产业化技术开发现状,报道了清华大学实验室与重庆英力燃化有限公司合作开发的燃料级二甲醚中试试验结果,提出了未来二甲醚产业化的发展趋势。     

Enhanced stability of Fe-modified CuO-ZnO-ZrO2-Al2O3/HZSM-5 bifunctional catalysts for dimethyl ether synthesis from CO2 hydrogenation

A series of iron (Fe) modified CuO-ZnO-ZrO2-Al2O3 (CZZA) catalysts,with various Fe loadings,were pre-pared using a co-precipitation method.A bifunctional catalyst,consisting of Fe-modified CZZA and HZSM-5,was studied for dimethyl ether (DME) synthesis via CO2 hydrogenation.The effects of Fe loading,reaction temperature,reaction pressure,space velocity,and concentrations of precursor for the synthesis of the Fe-modified CZZA catalyst on the catalytic activity of DME synthesis were investigated.Long-term stability tests showed that Fe modification of the CZZA catalyst improved the catalyst stability for DME synthesis via CO2 hydrogenation.The activity loss,in terms of DME yield,was significantly reduced from 4.2％ to 1.4％ in a 100 h run of reaction,when the Fe loading amount was 0.5 (molar ratio of Fe to Cu).An analysis of hydrogen temperature programmed reduction revealed that the introduction of Fe improved the reducibility of the catalysts,due to assisted adsorption of H2 on iron oxide.The good stability of Fe-modified CZZA catalysts in the DME formation was most likely attributed to oxygen spillover that was introduced by the addition of iron oxide.This could have inhibited the oxidation of the Cu surface and enhanced the thermal stability of copper during long-term reactions.