New Metrics of Green Sorbents for CO2 Capturing

Significant progress has been made in the past decades in the capture, storage, and utilization of greenhouse gases, particularly CO2. In general, the synthesis of most of the available CO2 sorbents is not ecofriendly and can require multistep synthesis in order to prepare and/or activate, which is considered a strict violation of green chemistry principles (GCPs). Therefore, thinking of green frameworks to design chemical products and processes becomes essential to mitigate these challenges. This paper provides an in-depth review of available green sorbents for CO2 capture with an emphasis on those prepared from biorenewable materials and ionic liquids. A new metric is presented to classify these sorbents based on their degree of compliance to the GCPs, which could be a useful tool in selection of green alternatives. Due to the interdisciplinary nature of this research topic, a wide range of literature is available in multiple areas including but not limited to chemistry and engineering. Hence, this review targets a wide range of scientists including chemists, biotechnologists, material scientists, and meteorologists, as well as green industrial corporations.