Hydrothermal pretreatment technologies for lignocellulosic biomass: A review of steam explosion and subcritical water hydrolysis.

The pretreatment of lignocellulosic biomass enhances the conversion efficiency to produce biofuels and value-added chemicals, which have the potential to replace fossil fuels. Compared to physicochemical and other pretreatment techniques, the hydrothermal methods are considered eco-friendly and cost-effective. This paper reviews the strengths, weaknesses, opportunities and threats of steam explosion and subcritical water hydrolysis as the two promising hydrothermal technologies for the pretreatment of lignocellulosic biomass. Although the principle of the steam explosion in depolymerizing the lignin and exposing the cellulose fibers for bioconversion to liquid fuels is well known, its underlying mechanism for solid biofuel production is less identified. Therefore, this review provides an insight into different operating conditions of steam explosion and subcritical water hydrolysis for a wide variety of feedstocks. The mechanisms of subcritical water hydrolysis including dehydration, decarboxylation and carbonization of waste biomass are comprehensively described. Finally, the role of microwave heating in the hydrothermal pretreatment of biomass is elucidated.

Application of biomass derived products in mid-size automotive industries: A review.

The automotive industry is directly affected by the shortage of fossil fuels and the excessive pollution resulting from crude oil-based fuels has many adverse effects on the environment. The search for a greener and sustainable source of materials and fuels to power automobiles has ultimately led to the usage of biomass and biobased sources as the main precursor due to its graft availability and renewability. Biobased fuels developed have been shown to easily blend in with the existing automobile engines and to provide sustainable performance. Similarly, the usage of various biobased polymers, plastics, and composite materials as the structural materials for the construction of automobiles instead of crude oil sources have shown to be invaluable. The powering of automobiles with electricity is the future of the transportation industry to address the greenhouse gas emissions caused by fossil fuels. Hence, biobased lithium-ion batteries and supercapacitors have started to enter the mid-sized automotive industry. However, extensive commercialization of biobased products application in the automotive sector is underdeveloped. Hence it is customary to assess the various drawbacks of using biobased materials and identify the correct pathway for new research and development in this field. Therefore, this review covers various applications of biobased products in the automotive industries and mentions the active researches going on in this field to replace petroleum and crude oil-based sources with biobased sources.