Insolite 27+ Alkaline Pretreatment Of Lignocellulosic Biomass. Lignocellulosic biomass is one of the most abundant organic resources worldwide and is a promising source of renewable energy and bioproducts. The use of an alkali causes the degradation of ester and glycosidic side chains resulting in structural alteration of lignin, cellulose. Alkaline pretreatment involves the use of bases, such as sodium, potassium, calcium, and ammonium hydroxide, for the pretreatment of lignocellulosic biomass.