An Experimental Study On Electrolytic Regeneration Of Decarbonization Liquid By Potassium Alkali

Environmental problems due to emissions of greenhouse gases especially CO₂ have become major global problems in recent years. It is widely accepted that CO₂ is the main contributor to the global warming and climate change and it is urgent to cut CO₂ emissions. However, the high capital and operation cost makes it very difficult to implement CO₂ capture technologies. So it is urgent to do some further researches on process intensification in order to reduce the energy consumption.The chemical absorption process is the only method that has been industrially adopted in many processes, and has more recently been considered as a mechanism to control greenhouse gas emissions. Benfield method is a successful technology for CO₂ absorption, and has been widely used in fertilizer plants. However, the capital cost for CO₂ capture via chemical absorption process is very high, which mainly lies in the regeneration process.The conventional thermal stripping process consumes much energy. A new process for stripping process have been carried out using ion-exchange membrane electrolysis technology decarbonisation solution by potassium carbonate, which produces useful hydrogen as a byproduct. Carbon dioxide and hydrogen can be collected and used as reactants for catalytic reaction to produce methanol, witch can greatly reduce the energy consumption and production cost.In this work, the reaction mechanism of membrane electrolysis technology has been studied and the operation conditions (temperature, current density) have been optimized. High temperature favors the conductivity of the anolyte together with the mass balance of potassium in the anolyte, which are considered as a function of the duration of the constant current electrolysis experiment. With current density increasing, the CO₂ separation speed becomes higher. H2 production quantity is directly proportional to the current density However, the process at lower current density can reduce cell voltage, and reduce the energy consumption.By contrasting with the traditional thermal desorption process, the electrolytic process has the obvious energy conservation and economical benefits. The process using membrane electrolysis can enable the KHCO₃ conversion rate to achieve 100% in the recycling fluid, and H₂ generated in the cathode compartment, makes this method be more economical.The process at low current densities, proper high temperature and continuous electrolytic operation reduced the energy consumption by 18%.