Recent Development of Biodiesel Feedstocks and the Applications of Glycerol: A Review

Abstract

Biodiesel, as renewable and biological origin alternative diesel fuel, has been receiving a lot of concern throughout the world due to the energy needs and environmental awareness. However, at present, it is not economically feasible to use food-grade vegetable oils to produce biodiesel because of the surge in feedstocks price. Much attention has been devoted to the application of lower-cost feedstocks to produce biodiesel. This paper provided a comprehensive review of biodiesel production from lower-cost non-edible oil sources, such as waste cooking oil (WCO), grease, soapstock, Jatropha oil, and algae. The engine performances of biodiesel produced from these feedstocks were further evaluated. This review also investigated the various applications for the value-added products from glycerol, the byproduct of biodiesel. Moreover, the challenges in terms of different feedstocks and by-product applications were further pointed out.

Review on recent progress in catalytic carboxylation and acetylation of glycerol as a byproduct of biodiesel production

“…Researchers have recently focused on upgrading glycerol into fine chemicals [6,7,10,12,[36][37][38][39][40][41] through reaction pathways, such as selective oxidation, dehydration, acetylation, transesterification, steam reforming, hydrogenolysis, and etherification ( Fig. 1) [1,[42][43][44][45].…”

“…As such, a low-cost alternative route, that is, using low-cost feedstock in BD production, has been proposed to reduce or avoid the utilization of food-grade materials [2]. These low-cost feedstocks can be sourced from non-edible oil sources, waste cooking oil, grease, Jatropha seed oil, and algae [1,6]. Nevertheless, the quality of feedstock utilized in BD production must be assessed for impurities, which may reduce the quality and affect the market value of the synthesized BD [7].…”

A Review of Enzymatic Transesterification of Microalgal Oil-Based Biodiesel Using Supercritical Technology

“…This consists of the reaction between TG and an acyl-acceptor [11, 63]. Carboxylic acids, alcohols, or another ester can be used as acyl-acceptor.…”

Rhizoclonium grande Bioethanol in Biofuel Production by Transesterification of Jatropha curcas Oil

“…This may be attributed to loss during pressing by evaporation and wetting of the cold press. Jatropha curcas kernels have about 50% oil [21]. The oil recovery in mechanical expeller is about 85%, while more than 95% recovery of oil could be achieved when extracted by solvent method.…”