Maximizing biodiesel production from high free fatty acids feedstocks through glycerolysis treatment

A comprehensive review of the polyolefin composites and their properties

“…The flexible types of PVC are used as an alternative to rubber and are applied in plumbing, electrical cable insulation, imitation leather, flooring, manufacturing of clothing, footwear/boot grades, upholstery, and electrical and cable compounds [ 38 , 52 , 53 ]. PVC is a thermoplastic with low thermal stability, hence, the use of PVC polymer is limited in the industry that requires high temperature [ 54 , 55 ].…”

Production of Biodiesel from Recycled Grease Trap Waste: A Review

“…19,43,86−88 In terms of the noncatalyzed process, the recent introduction of supercritical transesterification has attracted much attention. 11,51,89,90 Normally, supercritical transesterification is a self-catalyzed process since catalysts, H + , and OH − , are formed during special operational conditions. However, despite the cost benefit that this process can provide, it is waiting to be applied across the industry, because of the critical reaction conditions and the relatively high cost of the associated equipment.…”

“…Typically, the transesterification process can be divided into two reactions: catalyzed and noncatalyzed transesterification. Three types of catalysts can be utilized for the process, namely homogeneous, heterogeneous, and enzymatic catalysts. ,,− In terms of the noncatalyzed process, the recent introduction of supercritical transesterification has attracted much attention. ,,, Normally, supercritical transesterification is a self-catalyzed process since catalysts, H + , and OH – , are formed during special operational conditions. However, despite the cost benefit that this process can provide, it is waiting to be applied across the industry, because of the critical reaction conditions and the relatively high cost of the associated equipment.…”

“…Previous studies have emphasized that the expensive cost of feedstocks is the main impediment to the industrialization and commercialization of biodiesel. − The production from virgin feedstocks (e.g., edible oils) is plagued by the fact that the feedstock represents up to 70%–88% of the production cost, making biodiesel an expensive fuel, in comparison with mineral diesel. In addition, the use of farmland for feedstock cultivation has also raised concerns, in terms of soil impoverishment and food security.…”

Obtention of biodiesel through an enzymatic two-step process. Study of its performance and characteristic emissions

“…10 However, the high concentration of FFAs in this inexpensive waste feedstocks make necessary an additional step to decrease the FFA content below 1.0% to minimize the possibility of the alkali soap formation. 11 The use of lipases is an alternative when the feedstock contains a high amount of FFAs because it allows obtaining a purer product without soap production. However, biocatalysis has limitations, mainly the high cost of enzymes and the inhibition of lipase activity by short-chain alcohols.…”