Biogas upgrading using ionic liquid [Bmim][PF6] followed by thermal-plasma-assisted renewable hydrogen and solid carbon production

Abstract

The use of hydrogen as clean energy has attracted significant attention because conventional industrial hydrogen production processes show negative environmental impact, require intensive energy, and/or are dependent on natural gas. The main objective of this study is to develop an innovative and environment-friendly hydrogen production process utilizing biogas as an alternative to natural gas. Ionic liquid [Bmim][PF6] shows high potential for the replacement of aqueous amine solutions for CO2 absorption and are employed for biogas upgrading, while thermal plasma (TP), which is beneficial for converting electrical energy to chemical energy, is employed for the simultaneous production of clean “turquoise” hydrogen and solid carbon. In addition, an intercooler is used to improve CO2 removal in the absorber. Heat and power integration are employed to enhance the performance of the upgrading process and thermal-plasma-assisted hydrogen production. All simulations were conducted using Aspen Plus V10.0 software. The simulated results show that the solid carbon production from biomethane increases compared to that in the proposed base case. The savings in both the heater used to preheat the TP reactor and the third flash drum are 100%, while the saving in power consumption in the compression section is 62.0%. Furthermore, sensitivity is investigated to determine the effect of biomethane composition on the performance of the proposed configuration.