Application of heterogeneous acid catalyst derived from biomass for biodiesel process intensification: a comprehensive review

Abstract Hordes of viable methods to prepare catalysts from biomasses are available for enriching the quality and yield of biodiesel. The heterogeneous acid catalysts are advantageous because of their reactivity toward low-valued feedstocks and reusability. The latest studies on biodiesel production using green catalytic processes promote the use of biomass-derived solid acid catalysts as a result of their low price and eco-friendly attribute, leading to a sustainable biodiesel production. This review focuses on the discussion of various heterogeneous acid catalysts derived from biomass with an added emphasis on polycyclic aromatic hydrocarbons containing sulfonic acid group. Their effects on acid site strength, porosity as well as surface hydrophobicity for biodiesel production have also been discussed in this chapter. The use of these biomass derived catalysts paves a greener route for biodiesel production.