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.