Redox Combustion of Methanol, Methane and Carbon Monoxide in Molten (Li⁺, Na⁺, K⁺) ₂ (CO₃^2-, SO₄^2-) Mixtures at 550-650°C

Abstract

The authors proposed the “Molten Salt Redox Combustion Energy System”, which will be realized recovering the pure carbon dioxide with combustion of fuels in molten salt. We predict that the combustion at this system can be realized the two reactions in molten (Li⁺, Na⁺, K⁺) ₂ (CO₃^2-, SO₄^2-). One is the reduction of the alkali sulfate to sulfide with fuels. And the other is the oxidation of the sulfide to sulfate with air. We attempted that the reduction of the sulfate with methanol as fuels and the oxidation of the sulfide with air in the molten (Li⁺, Na⁺, K⁺) ₂ (CO₃^2-, SO₄^2-), at the temperature range 550 to 650°C. When the methanol was reacted in the molten salts under inert atmosphere, CO₂, CO, H₂O and H₂ were formed. At 650°C, combustion product CO₂ yield in carbon component was 0.81. The activation energy of methanol reaction in the molten salts was 107 kJ·mol^-1. When the oxidation of the sulfide with air was conducted after the methanol reaction, the sulfate regeneration with exothermic reaction was confirmed.