Process design for sorption-enhanced chemical looping steam methane reforming: Selection of process configuration and combustible gas type

Process efficiency of sorption-enhanced chemical looping steam methane reforming for H 2 production were developed. The effects of reactor arrangement, namely reforming-oxidation-calcination (R-O-C) and reforming-calcination-oxidation (R-C-O) systems, and combustible gas type (CH 4 vs. H 2 ) were analyzed through process simulation. The results showed that the R-O-C exhibited higher H 2 production and process efficiency than the R-C-O, regardless of combustible gas type. However, the R-O-C produced CO 2 during the oxidation step due to heat release from the oxidation reaction. Using CH 4 as a combustible gas resulted in greater process efficiency than H 2 but led to increased CO 2 emissions, requiring additional CO 2 capture units. Among all cases studied, the R-O-C using CH 4 as a combustible gas achieved H 2 purity of 87% and process efficiency of 75% at a steam-to-carbon ratio (S/C) of 3, a calcium oxide-to-carbon ratio (CaO/C) of 1, and a nickel oxide-to-carbon ratio (NiO/C) of 0.5 at 600 °C and 1 bar. • Sorption-enhanced chemical looping steam methane reforming shows high H 2 production. • Reactor arrangment and combustible gas type affect process thermal efficiency. • Reactor arrangment and combustible gas type influence CO 2 emissions. • Using CH 4 as a combustible gas provides high thermal efficiency and CO 2 emissions. • CO 2 capture unit is not required for the process using H 2 as a combustible gas.