Overview of Biodiesel Production Processes

Abstract

The global population and energy demand are rapidly growing, creating harmful environmental impacts such as climate change and acidification, due to undesirable pollutant emissions from increasing fossil fuel consumption. Hence green alternatives to energy sources are needed, and biofuels produced through eco-friendly approaches are attracting worldwide attention. Of the different kinds of biofuels available, researchers have identified biodiesel as one of the most promising alternatives, as it can be used as an alternative to petrodiesel. Fuel characteristics such as lower greenhouse gas emissions, higher biodegradability, minimal combustion toxicity, and compatibility with existing engines are reasons behind the growth of the biodiesel industry. A wide range of feedstocks from four different generations, i.e. edible and non-edible vegetable oils, animal fats, waste cooking oils, and algal biomass, are possible candidates for biodiesel production. Various production technologies, diverse reactions and separation and purification operations, and different types of catalysts have been employed in biodiesel production processes with a range of feedstocks. The quality and yield of biodiesel are affected by the feedstock type and amount, catalyst type and loading, molar ratio of alcohol to feedstock, and reaction conditions such as operating temperature and reaction time. This chapter presents an overview of the biodiesel production process, covering state-of-the-art processing technologies for biodiesel production, separation, and purification stages, and effects of process parameters on biodiesel production. Favorable processes for commercial-scale biodiesel production with higher quality and yields are compared and discussed.