A novel photo-thermochemical cycle for the dissociation of CO 2 using solar energy

Detailed kinetic modeling of homogeneous H2SO4 decomposition in the sulfur–iodine cycle for hydrogen production

“…Reactions (2) and (3) showed positive sensitivity to O 2 concentration but negative sensitivity to reaction (20) within 10 À9 s to 10 À5 s. Above 10 À5 s, O 2 concentration was sensitive to reactions (3), (12), and (13). Reaction (13) displaced reaction (3) in having the greatest influence on O 2 generation when the temperature was increased to 1200 K.…”

“…The O 2 production rates for reactions (3), (12) both were increased with increasing temperature at a fixed H 2 O/SO 3 ratio, but the increase of reaction (12) was more obviously. Nevertheless, the O 2 production rates for reactions (3) and (12) rapidly decreased as the H 2 O/SO 3 molar ratio increased at a fixed temperature (Fig. 7).…”

“…The three chemical reactions in the SI cycle are described as follows: Reaction (b) principally consists of a dehydration process at approximately 727 K and a catalytic decomposition process of SO 3 at approximately > 973 K. The former process produces gaseous SO 3 and H 2 O, whereas the latter process produces SO 2 In the SI cycle and hybrid sulfur cycle, the sulfuric acid decomposition section demanding the highest temperature and sulfuric acid concentration leads to the largest energy consumption. Previous studies [6,7] revealed that H 2 SO 4 is rapidly converted into SO 3 and H 2 O at 773 K [8]; however, the temperature needed for SO 3 to be converted into SO 2 focused on reaction (e). Sulfur trioxide electrolysis is conducted to reduce the maximum operating temperature to 773-823 K [8,9].…”

“…With the growth of global energy demand and the urgency of reducing greenhouse gas emissions [1][2][3], hydrogen has become a new and promising energy carrier. Thermochemical water splitting is becoming one of the popular methods for large-scale hydrogen production.…”

Catalytic decomposition of sulfuric acid over CuO/CeO2 in the sulfur–iodine cycle for hydrogen production

“…Water is a promising candidate raw material for large-scale hydrogen production, which can help solve the energy problem and reduce greenhouse-gas emissions [1,2]. The sulfureiodine (SI) cycle with good thermal efficiency and operability is receiving increased attention among the large number of thermochemical water-splitting processes [3].…”