15 March 2020
AGROinLOG has evaluated the feasibility of producing green chemicals from herbaceous biomass. The motivation was to valorise these type of crop residues in Spain where there is high availability. Namely, the production of levulinic acid and furfural was demonstrated using different herbaceous biomass: corn stalks, wheat straw and barley straw.
Levulinic acid can be used as ‘green’ chemical precursor for use in chemical and pharmaceutical industries. It is considered a platform chemical and is used for the production of herbicides (aminolevulinic acid), plasticizers, cross-linker, fuel additives, coatings, solvent and in cosmetics (fragrances and perfumes). Furfural and its derivatives can be used in plastics, pharmaceutical and agrochemical industries. Furthermore, it is a natural precursor to a range of furan-based chemicals and solvents. Both chemicals have growth expectancy in the market.
Currently, the commercial production of furfural is largely based on sugar cane bagasse, which is an important and abundant by-product of the cane sugar production. Commercial production of levulinic acid is mainly based on corn.
In AGROinLOG, the simultaneously production of levulinic acid and furfural from herbaceous biomass was investigated in more detail. Here fore, a process was chosen in which lignocellulosic biomass is impregnated with acid, drained and subsequently subjected to a flow of hot steam in a pressure reactor. The lignocellulose complex is degraded, (hemi)cellulose is hydrolyzed to monosaccharides and the monosaccharides are further dehydrated to yield furfural and hydroxy-methylfurfural (HMF). The C5 carbohydrates are converted into furfural and the C6 carbohydrates into HMF that is subsequently converted into levulinic acid and formic acid.
Thus, herbaceous biomass can be used to produce ‘green’ chemicals. The economic viability to use herbaceous biomass for manufacturing these chemicals is linked to competition with other biomass sources (corn cobs, bagasse/ sugar, starch) and the potential scale of operation, such as commercial or large commercial plant. The competition with food production is avoided when instead of sugar and starch, straws (e.g. wheat, rice) are being utilized.
The combined production of levulinic acid and furfural is advantageous as both bio-commodities can be produced and the herbaceous biomass potential can be fully exploited. The business case analysis of this combined production process showed that the process for the production of furfural and levulinic acid from wheat straw could be economically viable.