ABSTRACT
The reduction of greenhouse gas (GHG) emissions from solid waste incinerator fly ash (IFA) management attracts growing interests since China's zero-waste plan and carbon peak/neutral goals. Herein, provincial GHG emissions from four demonstrated IFA reutilization technologies in China were estimated after analyzing IFA spatial-temporal distribution. Results indicate that technologies transition (landfilling-to-reutilization) could reduce GHG except for glassy slag production. IFA to cement option could potentially realize negative GHG emissions. Spatial GHG variation drivers in IFA management were recognized as provincial-different IFA composition and power emission factors. IFA management options were recommended provincially after weighting local development goals related to GHG reduction and economic benefits. Baseline scenario analysis shows that China's IFA industry would reach carbon peak in 2025 (5.02 Mt). 2030's GHG reduction potential (6.12 Mt) is equivalent to that of absorbed CO2 by 340 million trees annually. Overall, this research could contribute to illustrating future market layout complying with carbon peaking.
ABSTRACT
The biomass-derived platform compound 5-hydroxymethylfurfural (HMF) has been hailed as the "Sleeping Giant" due to its promising applications, and it occupies a critical spot in the biomass upgrading roadmap. HMF is typically produced from cellulose and its monosaccharides via a complex tandem conversion with multiple steps (i. e., cellulose depolymerization, glucose isomerization, fructose dehydration, etc.). Previous investigations have confirmed the irreplaceable contribution of solvents in regulating the tandem conversion of cellulose and its monosaccharides to HMF. However, the potential effects of solvents in contributing to this multi-step tandem process have not yet been clearly elucidated. In this context, this Review aims to provide in-depth insights into the intrinsic interactions between solvent system and substrate conversion (cellulose and its monosaccharides conversion), reaction regulation (reaction activity and selectivity regulation), as well as product acquisition (humins formation inhibition and product purification). It attempts to elucidate specific solvent effects to promote a more efficient tandem conversion of cellulose and its monosaccharides towards HMF. The insights provided in this Review may contribute to a more sustainable HMF production from biomass feedstocks and a further development of greener solvent systems.
