Sustainable Processes Reusing Biomass Potassium-Rich Ash as a Green Catalyst for Biodiesel Production: A Mini-Review

To mitigate the emissions of greenhouse gases from fossil fuels, biodiesel production has be-come more attention over the past decade, especially for the use of waste cooking oils and non-edible oils as starting feedstock. For the biodiesel production process, the suitability of a catalyst is a core function implemented in the transesterification reaction. heterogeneous cata-lysts were superior to homogeneous catalysts due to some advantages such as no saponification products formed, recyclability, and less equipment corrosion. Recent studies also revealed that heterogeneous solid base catalysts are widely used for the production of biodiesel. Further-more, the biomass-based ash derived from herbaceous & agricultural biomass is increasing rap-idly because of its environmental sustainability, high biodiesel yield and low catalyst cost. To search for the depth of green catalysts, this mini-review paper thus focused on the summary of various heterogeneous biomass-based potassium-rich catalysts for the sustainable production of biodiesel. Due to cocoa pod husk that’s rich in potassium-containing minerals, it was found that its derived ash may be the most commonly used solid base catalyst in the biodiesel production.