CO₂ Capture for Dry Reforming of Natural Gas: Performance and Process Modeling of Calcium Carbonate Looping Using Acid Based CaCO₃ Sorbent

Several industrial activities often result in the emissions of greenhouse gases such as carbon dioxide and methane (a principal component of natural gas). In order to mitigate the effects of these greenhouse gases, CO₂ can be captured, stored and utilized for the dry reforming of methane. Various CO₂ capture techniques have been investigated in the past decades. This study investigated the performance and process modeling of CO₂ capture through calcium carbonate looping (CCL) using local (Malaysia) limestone as the sorbent. The original limestone was compared with two types of oxalic acid-treated limestone, with and without aluminum oxide (Al₂O₃) as supporting material. The comparison was in terms of CO₂ uptake capacity and performance in a fluidized bed reactor system. From the results, it was shown that the oxalic acid-treated limestone without Al₂O₃ had the largest surface area, highest CO₂ uptake capacity and highest mass attrition resistance, compared with other sorbents. The sorbent kinetic study was used to design, using an Aspen Plus simulator, a CCL process that was integrated with a 700 MWe coal-fired power plant from Malaysia. The findings showed that, with added capital and operation costs due to the CCL process, the specific CO₂ emission of the existing plant was significantly reduced from 909 to 99.7 kg/MWh.