Chemistry

Ecology

Transesterification

Ionic liquid

Biodiesel production

Biomass (ecology)

Environmentally friendly

Methanol

Chlorella vulgaris

Botany

Agronomy

Catalysis

Organic chemistry

Pulp and paper industry

Biodiesel

Algae

Biology

Biofuel

Waste management

Engineering

Biomass and Bioenergy

In this study, four types of tetrabutylphosphonium carboxylate ionic liquids (ILs) were synthesized and used for a one-pot transesterification of wet Chlorella vulgaris (C. vulgaris) microalgae into fatty acid methyl esters (FAME) in the presence of methanol, as well as refined oils (sunflower, canola, and corn oil). The resulting process removed the need for complete drying and lipid extraction steps typically needed for biodiesel production from microalgae. The leading candidate ionic liquid catalyst, tetrabutylphosphonium formate ([P4444][For]), was further optimized using response surface methodology to minimize material consumption, increase water compatibility, reduce processing time while maximizing yield from wet microalgae biomass. The optimized conditions resulted in a yield of 98.0 ± 2.48% using biomass containing 40 wt% water. Finally, the reusability of the ionic liquid was confirmed and [P4444][For] could be recycled with less than 2% loss between cycles. Due to the simple and low cost of synthe...

Direct transesterification of wet microalgae to biodiesel using phosphonium carboxylate ionic liquid catalysts