Sustainable green pretreatment approach to biomass-to-energy conversion using natural hydro-low-transition-temperature mixtures

Abstract

Natural hydro-low-transition-temperature mixtures (NH-LTTMs) tend to be the most favorable next-generation green solvents for biomass pretreatment, as they are cheap and environmental friendly. The amount of water bound into the NH-LTTMs greatly affected their thermal stability, whereby the highest thermal stability was observed with the water content of 7.6 wt%. It is worth noting that, the highest molar transition energy of NH-LTTMs (47.57 kcal mol), which indicated the highest solubility, was optimized with the molar ratio of hydrogen bond donor (HBD)-hydrogen bond acceptor (HBA)-water (2:4:3) at a temperature of 60 °C. Hydrogen bonding networks of the NH-LTTMs, which led to the dissolution of biomass, were confirmed by the alteration in the peaks of the involved bonds and resonance signal to lower field through FTIR and H NMR spectra, respectively. The components evidenced in high-resolution mass spectra of extracted lignin showed its high potential to be valorized into useful fuels and chemicals.

Recent advances in green solvents for lignocellulosic biomass pretreatment: Potential of choline chloride (ChCl) based solvents

“…In addition, the pretreatment with LTTMs is capable of achieving a higher extraction yields as compared to conventional solvents (Kottaras et al, 2017). For instance, a study conducted by Yiin et al (2018) involving the pretreatment of lignocellulosic biomass with malic acid-based LTTMs demonstrated high delignification selectivity, and improved enzymatic hydrolysis, as well as thermal degradation of biomass.…”

“…Valorizing, instead of disposing these biomass wastes is utterly important as these biomass wastes can serve as alternative feedstocks in place of the depleting fossil fuels, as well as to be transformed into various value-added products such as bio-derived fine chemicals and bio-fuels. Most importantly, they serve as inexpensive energy sources for the production of enzyme which are beneficial for microbial fermentation (Anwar et al, 2014;Yiin et al, 2018). As such, lignocellulosic biomass has indeed caught the interests of many researchers in recent times due to their nature of being renewable and cheap.…”

Switchable deep eutectic solvent driven micellar extractive fermentation of ultrapure fibrin digesting enzyme from Bacillus subtilis

“…Therefore, it could be conclusive from the above postulations that SDES with moderate density (TX: CCL) acts selectively toward effective extraction of fibrinolytic protease. A similar investigation using a hydrolow transition-temperature mixture for the biomass pretreatment of lignin concluded effective product recovery using mixtures with moderate density (31).…”

Increased productivity of liquid smoke through fast thawing with refrigeration systems at low air temperatures

“…The amount of waste must be managed into a valuable and economical product such as liquid smoke [3]. Many ways have been taken in the management of palm shell waste such as environmentally friendly liquid smoke with various techniques and different results, as has been done by several researchers [4]- [6]. Palm kernel shell is one of the many types of solid waste from the palm oil processing industry which still causes problems for the environment, this waste is difficult to degrade in large quantities and is difficult naturally in the environment [7].…”