The Road to Biorenewables: Carbohydrates to Commodity Chemicals

Abstract

The pressing need for climate change mitigation has focused attention on reducing global emissions of carbon dioxide by effectuating the transition from fossil-based chemicals manufacture to a carbon neutral alternative based on lignocellulosic waste. The first step involves fractionation of the lignocellulose into cellulose, hemicellulose, and lignin. Subsequently, a cellulase enzyme cocktail is used to catalyze the hydrolysis of the polysaccharides into their constituent sugars. This is followed by selective conversion of the carbohydrates into commodity chemicals using a variety of sustainable bio-and chemocatalytic methodologies. These include, inter alia, fermentative production of alcohols, diols, and carboxylic acids and a variety of chemocatalytic reductions and oxidations. Hence, the transition from fossil feedstocks to lignocellulose represents a switch from hydrocarbons to carbohydrates as the primary basic chemicals. To compare these renewable biomass-based routes with their petrochemical equivalents, it is necessary to develop reliable sustainability metrics.

Development of Fully Bio‐Based Lubricants from Agro‐Industrial Residues under Environmentally Friendly Processes

“…It is also important to highlight that the reactants employed in this work—acetic acid, acetic anhydride, and formic acid—are bio‐based building blocks which can be obtained from biorefineries, originated from different polysaccharide waste streams produced in the current industries. [ 27 ]…”

Catalytic Oxidations in a Bio-Based Economy

“…First generation (1G) renewable raw materials, exemplified by corn starch, sugar cane, and sugar beet, are not perceived as sustainable options in the long term as their utilization involves, directly, or indirectly, competition with food production. In contrast, the use of second generation (2G) renewable biomass, in the form of waste polysaccharides, such as lignocellulose (Liguori and Faraco, 2016;Zhang et al, 2017) and pectin, from agricultural and forestry residues and food supply chain waste (Dahiya et al, 2018), is perceived as a sustainable long term option for producing biofuels and commodity chemicals (Sheldon, 2014(Sheldon, , 2016(Sheldon, , 2018Horváth et al, 2017). Looking further afield, third generation (3G) aquatic biomass, such as micro-and macro-algae and cyanobacteria, has additional advantages (John et al, 2011;Al Abdallah et al, 2016;Shuba and Kifle, 2018).…”

Direct biodiesel production from wet spent coffee grounds

“…Currently biodiesel production relies on vegetable oil as a source, which further exacerbates the food vs. fuel debate. 13 The utilization of feedstocks which require a lot of water for cultivation (drink vs. fuel) has also been critiqued. 14 Consequently nding low-cost feedstocks which contain high lipids is necessary to increase biodiesel competitiveness.…”