관형 Pt-라이닝 반응기를 이용한 가압 황산분해반응

Abstract

Sulfur-Iodine (SI) cycle, which thermochemically splits water to hydrogen and oxygen through three stages of Bunsen reaction, HI decomposition, and H_2SO_4 decomposition, seems a promising process to produce hydrogen massively. Among them, the decomposition of H_2SO_4 (H_2SO_4 = H_2O + SO_2 + 1/2 O_2) requires high temperature heat over 800℃ such as the heat from concentrated solar energy or a very high temperature gas-cooled nuclear reactor. Because of harsh reaction conditions of high temperature and pressure with extremely corrosive reactants and products, there have been scarce and limited number of data reported on the pressurized H_2SO_4 decomposition. This work focuses whether the H_2SO_4 decomposition can occur at high pressure in a noble-metal reactor, which possibly resists corrosive acidic chemicals and possesses catalytic activity for the reaction. Decomposition reactions were conducted in a Pt-lined tubular reactor without any other catalytic species at conditions of 800℃ to 900℃ and 0 bar (ambient pressure) to 10 bar with 95 wt% H_2SO_4. The Pt-lined reactor was found to endure the corrosive pressurized condition, and its inner surface successfully carried out a catalytic role in decomposing H_2SO_4 to SO_2 and O_2. This preliminary result has proposed the availability of noble metal-lined reactors for the high temperature, high pressure sulfuric acid decomposition.