Pilot Plant for Capturing CO2 Using a Precipitating Potassium Carbonate Solvent

Abstract

The Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) researches and develops technologies for carbon dioxide capture and geological storage of carbon dioxide. The CO2CRC solvent capture group are developing a novel precipitating potassium carbonate (K2CO3) process, known as UNO MK 3, which is designed to capture 90% of carbon dioxide (CO2) emissions from large scale emission sources such as power stations. Some of the key benefits of this process, compared to traditional amine based capture processes, include lower regeneration energy, lower overall cost, low volatility and environmental impact, low toxicity and the ability to incorporate multi-impurity capture of CO2, SOx and NOx and production of valuable by-products. Demonstration of this precipitating potassium carbonate process is underway using a laboratory based pilot plant located at The University of Melbourne. The pilot plant has been designed to capture 4 - 10 kg/hr of CO2 from an air/CO2 feed gas rate of 30 – 55 kg/hr. Initial trials have been completed using solvent concentrations ranging from 20 to 40 wt% K2CO3 with and without a rate promoter. Performance data collected from the plant is presented fora range of operating conditions. Plant data (including temperature profiles, solvent loadings and exit gas CO2 concentrations) have also been used to validate and further develop Aspen Plus simulations.