33.3 Evaluation of Waste Cooking Oil and Valorized Cooking Oil

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filtration process. The WCO is separated based on its boiling point. The raw material

is subjected to a few common processes like subjecting to an unpolished filtration to

remove solid contaminants and later heating under vacuum. At a constant reduced

pressure, distilled crude oil is purified from the volatile fraction which results in

refined oil. The quality of the final product of the recycled oil depends not only on

the quality of the WCO but also on the special configuration of the machines.

33.2.2

Microbiological and Biotechnological Treatment

Utilized vegetable oils have the potential to be used as low-cost and copious

substrates for the microbial growth and metabolite production. This process will

help to reduce the production costs of valuable compounds and also becomes

environment-friendly. According to various studies, it is seen that oxygen has a

vital role in the biosynthesis of microbial lipids from oils and fats. Meanwhile, if a

water-immiscible substrate is used, oils can coat the gas–liquid interface with their

layer and reduce the oxygen mass transfer to the culture medium [14].

33.3

Evaluation of Waste Cooking Oil and Valorized

Cooking Oil

Increasing demand and huge consumption of biofuels and the lesser availability of

raw materials for their manufacturing are motivating factors for the exploration of

substitute methods and raw materials. Utilized vegetable oil which is produced as

effluent in food chains and outlets worldwide in huge quantities need to be man-

aged skillfully. Biodiesel which is also known as “green fuel” is a perfect alternative

for petroleum as discussed earlier. Although on survey it was seen that the physical

and chemical properties of waste vegetable oil varies from fresh edible vegetable oil

in that waste oil exhibits a higher free fatty acids and moisture content than fresh

vegetable oil owing to the thermolytic, oxidative and hydrolytic reactions occurred

during frying. Different polymerized triglycerides are found in the WCO [15].

World’s largest chain of fast-food restaurants, hotels, food suppliers, and food

industries serves around 68 million clients daily in 119 countries across 35 000

outlets. Around 90% of the WCO produced is utilized as after use for various

industries. The WCOs from the food outlets are collected, recycled, and put back

into distributor’s trucks to fuel their distributions. Utilized vegetable oil is ware-

housed at the restaurants in a particularly designed ampule and then utilized for

delivery trucks to power the distribution fleets and are also sold to other companies

to reduce their transportation impacts [16]. The post-processing techniques are

essential which point toward the steps after the transesterification reactions which

are performed to purify the biodiesel in accordance with the existing rules and

regulations. Even though the final product depends a lot on the kind of feedstock

utilized, researchers have also concluded that the functioning temperature is a

foremost prevailing factor in the descent of the characteristics of fuel produced [17].