The Evaluation of Reactive Sorption Enhanced Biogas Steam Reforming Process for Hydrogen Production Using Nano-Sized CaO Adsorbents.

Abstract

The simulation of a biogas steam reforming process for hydrogen production with nano-sized CaO reactive sorption enhancement has been done to evaluate the performance of this new technology. First, the conversion of CH₄ in reforming reaction (XCH₄) and CO conversion in water shift reaction (XCO) were obtained from experimental results under different conditions of reaction temperature (T), steam to methane molar ratios (S/C) and calcium to total carbon molar ratios (Ca/CT). Then the technical performance indicators including yield of hydrogen and efficiency of biogas energy conversion were calculated based on the XCH₄ and XCO results. The evaluation results showed that the maximum values of yield of hydrogen (2.47 Nm³ H₂/Nm³ Biogas) and efficiency of energy conversion (88.25%) could be got when T was 600 °C, S/C was 4, Ca/CT was 2.75 and the reaction pressure was 1 atm. Compared with the conventional biogas steam reforming process without enhancement and the sorption enhanced biogas steam reforming process using micro-sized CaO adsorbents, this new technology using nano-sized CaO adsorbents owned higher purity and yield of hydrogen at lower reaction temperature, which revealed the stronger technical advantages.