Flexible strategies for carbon-negative syngas and biochar poly-generation via a novel chemical looping approach

This work proposed a pyrolysis chemical looping reforming-two stage regeneration (PCLR-TR) process with carbon-negative syngas and biochar poly-generation, aimed at overcoming challenges in chemical looping gasification. The process effectively separates pyrolysis and reforming, circumventing slow solid-solid reactions and enabling the flexible adjustment of the H2/CO ratio. The two-stage regeneration ensures improved synchronization of reaction rates across different reactors. The results indicate that manipulation of process parameters allows for flexible adjustment of the H2/CO ratio in syngas (ranging from 1.02 to 3.83). The introduction of CO2 feed in the first stage regeneration reactor reduces the oxygen carrier exothermic intensity in the second stage regeneration reactor by 58%. Optimization results suggest that the generated syngas is compatible with diverse downstream applications, exhibiting a maximum CO2 negative emission of 1.85 kg/kg syngas. The PCLR-TR system offers a versatile and environmentally friendly solution for the energy and chemical industries.