Enhanced high-purity syngas production and sustainable chemicals synthesis via chemical looping dry reforming of methane

Dry reforming of methane (DRM) utilizes two major greenhouse gases, CO 2 and CH 4 , to produce syngas (CO and H 2 ), which is an important chemical intermediate resource for high-value chemicals synthesis. However, conventional DRM faces challenges such as catalyst deactivation , low product selectivity, and an unsuitable syngas ratio for downstream chemicals synthesis. To address these limitations, we propose a chemical looping dry reforming of methane (CLDRM) method, which achieves high methane conversion, superior syngas selectivity, and high-purity syngas for chemicals synthesis. In this study, 100 cycles of experiments were carried out using the LaFe 0.8 Al 0.2 O 3 oxygen carrier. The results showed 88.3 % CH 4 conversion, over 99 % CO selectivity, and a syngas yield of 8.1 mmol/g with an H 2 /CO ratio of 2 during the methane partial oxidation (POx) step. In the CO 2 splitting step, the system achieved 81.3 % CO 2 conversion with a CO yield of 2.6 mmol/g. The energy upgrade factor during the cycle reached 1.98. Furthermore, the performance of the proposed CLDRM-based chemicals production system was analyzed, taking acetic acid synthesis as a typical case. The new system achieved energy and exergy efficiencies of 62.9 % and 65.4 %, respectively, representing improvements of 11.5 % and 12.2 % compared to the conventional DRM system. Additionally, the new system reduced methane consumption by 8.84 % while increasing the CO 2 fixation rate by 50.54 %. In summary, the proposed CLDRM process offers a promising pathway for CO 2 reduction and cleaner utilization of CH 4 for high-value chemicals production, supporting the transition to a more sustainable and low-carbon future. • Efficient and low-carbon conversion of methane and carbon dioxide by CLDRM. • Achieve 88.3 % CH 4 conversion, >99 % CO selectivity with a stable H 2 /CO ratio of 2. • LaFe 0.8 Al 0.2 O 3 demonstrates stable performance over 100 cycles in the CLDRM. • A system for acetic acid production by combining CLDRM method is proposed. • The energy efficiency and exergy efficiency of the proposed system are 62.88 % and 65.38 %.