共查询到20条相似文献,搜索用时 13 毫秒
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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. 相似文献
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Ashkan Khoshkharam Mohammad Ali Ghayyem Reza Mosayyebi Behbahani 《Petroleum Science and Technology》2017,35(5):471-478
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. 相似文献
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N. I. Laguntsov G. G. Kagramanov I. M. Kurchatov M. D. Karaseva 《Petroleum Chemistry》2017,57(2):132-138
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). 相似文献
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AbstractProcess 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. 相似文献
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湍球塔的传递及其在吸收二氧化硫系统中应用 总被引:1,自引:0,他引:1
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。 相似文献
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V. A. Naumov G. V. Kusyi V. B. Vorotyntsev T. L. Chelyshev T. F. Surzhikova 《Chemical and Petroleum Engineering》1991,27(10):550-554
Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 10, pp. 5–7, October, 1991. 相似文献
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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。 相似文献