Microfluidic cold stripping of H2S from crude oil in low temperature and natural gas consumption

Abstract

This study presents the results of removing H2S from crude oil using a micro scale stripper. The main issue in this work is reduction of natural gas consumption and use of low operational temperature. The effects of various operational parameters (such as: crude oil flow rate, natural gas flow rate and temperature of crude oil) on H2S removal efficiency (efficiency) and Specific Energy Consumption (S.E.C) are evaluated. The obtained results, even for lower amounts of the used gas (about one-third) and lower gas temperature (about 18 °C), show a higher efficiency of cold stripping using microchannel compared with other type of strippers. This superior result, with an efficiency of 77.80%, is related to efficient mixing by the employed microchannel at the proposed condition. It has been demonstrated that the efficiency increases with increasing the temperature of crude oil and natural gas flow rate, while temperature does not show a considerable effect on S.E.C. The efficiency and SEC have decreasing trend with increase in flow rate of crude oil at constant temperature and gas flow rate. The mathematical modeling is proposed for H2S removal and the relation between the parameters was determined using Response Surface Methodology (RSM) with Central Composite Design (CCD) method. The values of R2 and lack of fit (LOF), obtained from the mathematical model for efficiency, are 0.9589 and 0.2126, respectively. In addition, the values of R2 and LOF for S.E.C are 0.9981 and 0.0606.