Recent developments in polysaccharide and lignin-based (nano)materials for CO2 capture

Abstract

Global warming in 2023 shows no signs of slowing down. The situation alarms scientists, including the Intergovernmental Panel on Climate Change, the international body responsible for regularly developing knowledge on climate change. Indeed, some impacts are already threatening the environment. Today, the average global temperature has increased by about 1 °C compared to the pre-industrial era (1850–1900). At the current rate, the increase in global average temperature will reach 1.5 °C between 2030 and 2052. The greenhouse effect is unbalanced by human activities, in particular the use of fossil fuels (oil, gas, and coal), which lead to the release of greenhouse gases. CO₂ represents nearly 2/3 of global greenhouse gas emissions caused by human activities and has the tendency to linger in the atmosphere for a long time. This is why the effect of other greenhouse gases is usually measured in CO₂ equivalent. Current CO₂ emissions will impact atmospheric concentrations and global temperatures for decades. To date, some solutions have been proposed to deal with this (energy transition, regulation of emissions, etc.). However, most of these solutions have not yet been sufficiently developed and/or do not offset the effects of ever-increasing industrialization on anthropogenic CO₂ emissions. As a result, carbon capture and sequestration processes appear to be attractive solutions. CO₂ capture can take place by absorption (chemical and/or physical) and/or adsorption (chemisorption and/or physisorption). Various compounds can act as sorbents, among which polysaccharides and lignin have special importance due to their many advantages, the most important of which are biodegradability, availability, relatively cheapness, environmental friendliness, etc. In this review, we report recent studies regarding polysaccharides and lignin-based materials for CO₂ capture. Such materials can be in different forms such as composites, aerogels, hydrogels, pellets, heteroatom-doped materials, membranes, metal–organic frameworks (MOFs), porous carbons, etc. These materials are used for CO₂ capture through the adsorption or absorption processes.