Design of Ionic Liquid as Carbon Capture Solvent for a Bioenergy System: Integration of Bioenergy and Carbon Capture Systems

Abstract

Current atmospheric carbon dioxide (CO2) concentration has exceeded the safe limit of 350 ppm. One potential technology to remove CO2 from the atmosphere is the integrated bioenergy production and carbon capture system. A bioenergy production system produces multiple energy products from biomass, resulting in zero net increment of CO2 amount in the atmosphere. Meanwhile, CO2 produced from bioenergy production is separated for other purposes through carbon capture. To ensure the entire system is environmental friendly, an efficient and green carbon capture solvent should be utilized. Ionic liquids (ILs) are the potential solvents for this purpose, as they have negligible vapor pressure and high thermal stability. However, there are up to a million possible combinations of cations and anions that may make up ILs. This work presents a systematic approach to identify an optimal IL solvent to separate CO2 produced from a bioenergy system at the optimal conditions of carbon capture process. Following that, the bioenergy system is retrofitted to provide sufficient utilities to a carbon capture system to make sure that the entire process is self-sustainable. A case study involving an existing palm-based bioenergy system, integrated with carbon capture to produce CO2, is used to demonstrate the presented approach.