深冷轻烃中CO_2脱除工艺模拟分析

以油田深冷轻烃为原料,利用Aspen Plus工艺模拟软件,对原料脱除二氧化碳进行模拟设计。结果表明,采用提馏塔分离方案,在提馏塔最佳操作压力为1.6 MPa的条件下,可脱除深冷轻烃中质量分数为90%的二氧化碳,满足裂解装置对原料的要求。     

四丁基氯化铵半笼型二氧化碳水合物生成动力学研究

为明确四丁基氯化铵+CO_2+水体系下水合物生成的动力学特性,在可视化高压搅拌反应釜内进行四丁基氯化铵+CO_2+水体系水合物的动力学实验,探究了溶液中四丁基氯化铵浓度对诱导时间、快速生长时间、快速生长速率和累积耗气量的影响以及机理。实验结果表明,与纯水体系相比,随着四丁基氯化铵浓度的增加,诱导时间显著增加;5%(w)的四丁基氯化铵溶液对水合物的生成有抑制作用,而10%(w),15%(w)的四丁基氯化铵溶液则会促进水合物的生成,但是由于气体的大量消耗,驱动力减小,快速生成时间较短;随四丁基氯化铵浓度的增加,总的气体消耗量逐渐减小。     

Non-thermal inactivation of Escherichia coli K12 in buffered peptone water using a pilot-plant scale supercritical carbon dioxide system with a gas–liquid porous metal contactor

This study evaluated the effectiveness of a supercritical carbon dioxide (SCCO₂) system, with a gas–liquid porous metal contactor, for reducing Escherichia coli K12 in diluted buffered peptone water. 0.1% (w/v) buffered peptone water inoculated with E. coli K12 was processed using the SCCO₂ system at CO₂ concentrations of 3.1–9.5 wt%, outlet temperatures of 34, 38, and 42 °C, a system pressure of 7.6 MPa, and a flow rate of 1 L/min. Increased CO₂ concentrations and temperatures significantly (P < 0.05) enhanced microbial reduction. A maximum reduction of 5.8-log was obtained at 8.2% CO₂ and 42 °C. To achieve a 5-log reduction of E. coli K12 in 0.1% buffered peptone water, minimum CO₂ concentrations of 9.5%, 5.5%, and 5.3% were needed at 34, 38, and 42 °C, respectively. Further reductions of cells were observed after storage for 7 days at 4 °C. But storage at 25 °C increased the number of viable cells to 8-log cfu/mL after 7 days. This study showed the potential of the pilot scale SCCO₂ system with a gas–liquid porous metal contactor for microbial inactivation in liquid food.     

Laboratory investigation of carbon dioxide separation from methane using a PES/Pebax 1657 composite membrane

Removal of carbon dioxide from methane is a critical issue in the gas sweetening and treatment units. The aim of this study is to investigate the capability of PES/Pebax composite membrane in order to CO₂ removal from the CH₄. In this regard, permeability values of both carbon dioxide and methane have been measured. The ranges of temperature and pressure used for pure gases experiments were 20–50°C and 2.5–10 bar, respectively. Moreover, influence of CO₂ concentration on the CH₄ permeability and its selectivity was studied. Results indicated that the pressure and temperature have significant influence on permeability and selectivity. In addition, for the gas mixtures, experiments were carried out at 5 bar and 35°C. Results also indicated that at higher CO₂ concentrations the CO₂ permeability increased significantly.     

Natural gas drying and cleaning of carbon dioxide by membrane gas separation

To solve the problem of dehydration and CO₂ removal in natural gas purification, a membrane process scheme consisting of a two-stage countercurrent recirculation cascade has been proposed. The first stage is an ordinary separator, and the second stage is a two-module separator with recycle. This scheme allows natural gas cleaning to remove highly permeable impurities with any desired level of methane recovery. Optimal values of the main parameters of the given process flowsheet have been determined. Energy efficiency has been evaluated with taking account of the operating costs of interstage compression and methane loss (in energy units).     

Modeling of CO2 capture from gas stream emissions of petrochemical industries by membrane contactor

Abstract

Process optimization of CO₂ removal from natural gas by a polyvinylidene fluoride hollow-fiber membrane contactor is a major goal of many computational fluid dynamics (CFD) simulations in this area. In this study, a 2D CFD model based on mass transfer equation inside the tube, the membrane, and the shell section of a HMFC at steady state and laminar conditions is developed and solved by COMSOL Multiphysics with finite element approach. Simulation results show an excellent agreement with experimental data. The model predicts that higher liquid velocity and membrane porosity results in higher CO₂ removal, because of enhancement of effective diffusion coefficient. Also, taller fiber length results in higher contact area and higher mass transfer of CO₂ from natural gas into distilled water. Although higher temperature will decrease the CO₂ removal.     

二氧化碳气田气制液体二氧化碳的原料气预处理技术的改进

通过调整工艺流程,利用换热器对工艺流程内部不同工艺介质进行热量交换,即利用温度高的氨气对原料气进行加热,同时低温的原料气又对氨气进行降温,最大限度的利用了系统内部的能量转换和平衡,实现了节约能源,降低生产成本的目的。     

湍球塔的传递及其在吸收二氧化硫系统中应用

系统地介绍了湍球塔的流体力学行为和传质、传热、混合等传递过程及其工程设计计算。并以天然碱液吸收二氧化硫制得亚硫酸钠为实例,通过对部分设计结果的观察和测试,验证了设计计算的正确性。     

由二氧化碳直接合成碳酸二甲酯

由二氧化碳出发的直接合成是碳酸二甲酯合成的新方法 ,可以在金属烷氧基化合物、碱以及负载金属催化剂作用下进行。吸水剂及作为甲基化剂的碘化物的添加可有效提高反应的转化程度 ,反应在超临界二氧化碳溶剂中表现出更高的转化率 ,直接合成反应的核心是二氧化碳的活化 ,二氧化碳对M -O键的插入在反应机理中起关键作用。     

Nonisothermal dynamics of the absorption of water vapor and carbon dioxide from an air flow by NaX zeolite

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 10, pp. 5–7, October, 1991.     

改性煤基活性炭在高氟水处理中的应用研究

采用改性煤基活性炭处理高氟水,实验结果表明改性的煤基活性炭吸附反应速度快,最佳的pH为5-8,而且对氟离子具有较好的离子选择性能。     

K_2CO_3溶液脱除CO_2最佳浓度的研究

在实验室模拟脱碳装置上,对K2CO3溶液脱除CO2进行了实验研究。在恒定再生加热功率条件下以质量百分含量为18%～36%的K2CO3溶液考察了实验模拟装置的不同脱碳效果。结果表明w(K2CO3)为25%的溶液脱碳效果最佳。     

考虑地层水的凝析气井注CO2提高产能研究

注CO2吞吐被认为是解除凝析气井反凝析污染、提高气井产能的较好方法。利用CMG数值模拟软件,以一口实际的含水凝析气井数据为基础,建立了单井径向数值模拟模型。对比研究凝析气井自然衰竭开采和注CO2吞吐不同情况下,反凝析液饱和度和气相相对渗透率的变化规律,并利用陈元千的"动态污染表皮系数"法进行产能提高效果评价。研究表明:反凝析现象在近井带形成了一个10m左右的动态径向污染区,致使气井产能急剧下降。注CO2吞吐可通过CO2与凝析液的反蒸发作用有效地消除近井带的反凝析液污染,从而提高气井产能。CO2注入量越大,吞吐效果越好,但也存在一个最优值(实例为16×104m3),超过后的产能提高幅度明显减小,而注入速度和焖井时间对产能的提高不敏感。