One-step synthesis of DME (dimethyl ether) from syngas on hybrid catalyst is studied.In the experiment,the effects of variables including composition of feed gas,temperature and pressure are studied under the conditio...One-step synthesis of DME (dimethyl ether) from syngas on hybrid catalyst is studied.In the experiment,the effects of variables including composition of feed gas,temperature and pressure are studied under the condition as follows:the catalyst was composed of C302 methanol synthesis catalyst and CM-3-1 methanol dehydration catalyst (mixing ratio 1∶1).Liquid paraffin is used as inert solvent.The reaction temperature is in the range of 230-270?℃ and the pressure is in the range of 3.0-5.0?MPa.It turns out that with the temperature and pressure increasing the conversion of carbon,the selectivity and production rate of dimethyl ether increase,while the selectivity and production rate of methanol decrease.Furthermore,both the conversion of carbon and the selectivity of dimethyl ether are high for the syngas of appropriate CO 2.展开更多
To meet the rapidly increasing demand for energy and the dramatic depletion of conventional crude oil,it is imperative to utilize sour naphtha.With no coke being produced,oxidative desulfurization(ODS)of naphtha lower...To meet the rapidly increasing demand for energy and the dramatic depletion of conventional crude oil,it is imperative to utilize sour naphtha.With no coke being produced,oxidative desulfurization(ODS)of naphtha lowers its sulfur content and average molecular weight.In this article,we outline a method for heavy naphtha non-extractive ODS using a very stable catalyst.The technique involves the use of a solid catalyst with oxygen gas as the oxidant.This necessitated relatively high mixing intensities;hence a three-phase Oscillatory Baffled Reactor(OBR)was used.The catalyst was based on the zeolite ZSM-5,prepared from natural kaolin by a series of delamination and activation steps and impregnated with Fe.A TiO2 nanolayer was applied,using the sol-gel method,to prevent rapid deactivation.The reactor performance was evaluated to minimize the sulfur content in the naphtha fuel.Due to the protective coating,the sulfur conversion stabilized at 90%.The results of this work establish the use of natural clay-based catalysts in a continuous,three-phase ODS,particularly with regard to proving long-term stability.It also showed that modest ODS can be achieved using an environmentally friendly oxidant,at mild operating conditions,whilst maintaining stability.展开更多
A three-phase reactor mathematical model was set up to simulate and design a three-phase bubble column reactor for direct synthesis of dimethyl ether （DME） from syngas, considering both the influence of part inert c...A three-phase reactor mathematical model was set up to simulate and design a three-phase bubble column reactor for direct synthesis of dimethyl ether （DME） from syngas, considering both the influence of part inert carrier backmixing on transfer and the influence of catalyst grain sedimentation on reaction. On the basis of this model, the influences of the size and reaction conditions of a 100000 t/a DME reactor on capacity were investigated. The optimized size of the 10000 t/a DME synthesis reactor was proposed as follows： diameter 3.2 m, height 20 m, built-in 400 tube heat exchanger （Ф 38×2 mm）, and inert heat carrier paraffin oil 68 t and catalyst 34.46 t. Reaction temperature and pressure were important factors influencing the reaction conversion for different size reactors. Under the condition of uniform catalyst concentration distribution, higher pressure and temperature were proposed to achieve a higher production capacity of DME. The best ratio of fresh syngas for DME synthesis was 2.04.展开更多
随着社会发展和人民环保意识的提高,特高压(ultra high voltage,UHV)噪声污染的投诉与纠纷日益增多,已经成为制约电网绿色发展与建设的重要因素。通过对特高压变电站内主设备噪声的测量,发现三相电抗器噪声最大,且出现极大与极小值交替...随着社会发展和人民环保意识的提高,特高压(ultra high voltage,UHV)噪声污染的投诉与纠纷日益增多,已经成为制约电网绿色发展与建设的重要因素。通过对特高压变电站内主设备噪声的测量,发现三相电抗器噪声最大,且出现极大与极小值交替现象。说明电抗器噪声在传播过程中存在明显的干涉效应,这也是造成常用商业噪声软件的预测值与实测结果不符的主要原因。为解决此问题,基于有限元法(finite element method,FEM)声固耦合及有限元法-边界元法(FEM-boundary element method,FEM-BEM)耦合理论,使用数值仿真软件COMSOL对三相电抗器声源特性及声源等效模型建立方法展开研究。研究发现三相电抗器噪声频谱中100 Hz的声功率级占比全频带声功率级超过90%,说明100 Hz是造成干涉效应的主要频率。并基于此频率提出一种通过设置井型线声源的方法建立三相电抗器声源等效模型。结果显示:模型仿真计算的预测结果与实测值的趋势基本一致,差异在修正后实现了较高的吻合度。研究对于三相电抗器设备的噪声预测与治理具有现实指导意义,为特高压输变电工程的进一步精细化设计提供了一种有效思路与方法。展开更多
文摘One-step synthesis of DME (dimethyl ether) from syngas on hybrid catalyst is studied.In the experiment,the effects of variables including composition of feed gas,temperature and pressure are studied under the condition as follows:the catalyst was composed of C302 methanol synthesis catalyst and CM-3-1 methanol dehydration catalyst (mixing ratio 1∶1).Liquid paraffin is used as inert solvent.The reaction temperature is in the range of 230-270?℃ and the pressure is in the range of 3.0-5.0?MPa.It turns out that with the temperature and pressure increasing the conversion of carbon,the selectivity and production rate of dimethyl ether increase,while the selectivity and production rate of methanol decrease.Furthermore,both the conversion of carbon and the selectivity of dimethyl ether are high for the syngas of appropriate CO 2.
基金supported by a grant from Petroleum Research and Development Center,Ministry of Oil,Iraq(No.304/16/1/2022).
文摘To meet the rapidly increasing demand for energy and the dramatic depletion of conventional crude oil,it is imperative to utilize sour naphtha.With no coke being produced,oxidative desulfurization(ODS)of naphtha lowers its sulfur content and average molecular weight.In this article,we outline a method for heavy naphtha non-extractive ODS using a very stable catalyst.The technique involves the use of a solid catalyst with oxygen gas as the oxidant.This necessitated relatively high mixing intensities;hence a three-phase Oscillatory Baffled Reactor(OBR)was used.The catalyst was based on the zeolite ZSM-5,prepared from natural kaolin by a series of delamination and activation steps and impregnated with Fe.A TiO2 nanolayer was applied,using the sol-gel method,to prevent rapid deactivation.The reactor performance was evaluated to minimize the sulfur content in the naphtha fuel.Due to the protective coating,the sulfur conversion stabilized at 90%.The results of this work establish the use of natural clay-based catalysts in a continuous,three-phase ODS,particularly with regard to proving long-term stability.It also showed that modest ODS can be achieved using an environmentally friendly oxidant,at mild operating conditions,whilst maintaining stability.
基金This work was supported by the National Basic Research Program of China (2005CB221205)
文摘A three-phase reactor mathematical model was set up to simulate and design a three-phase bubble column reactor for direct synthesis of dimethyl ether （DME） from syngas, considering both the influence of part inert carrier backmixing on transfer and the influence of catalyst grain sedimentation on reaction. On the basis of this model, the influences of the size and reaction conditions of a 100000 t/a DME reactor on capacity were investigated. The optimized size of the 10000 t/a DME synthesis reactor was proposed as follows： diameter 3.2 m, height 20 m, built-in 400 tube heat exchanger （Ф 38×2 mm）, and inert heat carrier paraffin oil 68 t and catalyst 34.46 t. Reaction temperature and pressure were important factors influencing the reaction conversion for different size reactors. Under the condition of uniform catalyst concentration distribution, higher pressure and temperature were proposed to achieve a higher production capacity of DME. The best ratio of fresh syngas for DME synthesis was 2.04.
文摘随着社会发展和人民环保意识的提高,特高压(ultra high voltage,UHV)噪声污染的投诉与纠纷日益增多,已经成为制约电网绿色发展与建设的重要因素。通过对特高压变电站内主设备噪声的测量,发现三相电抗器噪声最大,且出现极大与极小值交替现象。说明电抗器噪声在传播过程中存在明显的干涉效应,这也是造成常用商业噪声软件的预测值与实测结果不符的主要原因。为解决此问题,基于有限元法(finite element method,FEM)声固耦合及有限元法-边界元法(FEM-boundary element method,FEM-BEM)耦合理论,使用数值仿真软件COMSOL对三相电抗器声源特性及声源等效模型建立方法展开研究。研究发现三相电抗器噪声频谱中100 Hz的声功率级占比全频带声功率级超过90%,说明100 Hz是造成干涉效应的主要频率。并基于此频率提出一种通过设置井型线声源的方法建立三相电抗器声源等效模型。结果显示:模型仿真计算的预测结果与实测值的趋势基本一致,差异在修正后实现了较高的吻合度。研究对于三相电抗器设备的噪声预测与治理具有现实指导意义,为特高压输变电工程的进一步精细化设计提供了一种有效思路与方法。
