Evaluation of Two-Step Reaction and Enzyme Catalysis Approaches for Biodiesel Production from Spent Coffee Grounds

Abstract

Currently, the biodiesel industry is investigating non-food crops with high oil content. The industry is also evaluating oil sources from deeper into the industrial or commercial waste streams. Spent coffee grounds could be a feedstock that qualifies for both as a non-food crop and a waste product. The purpose of this study is to evaluate the feasibility of using coffee oil extracted from spent coffee grounds as raw material to produce ASTM standard biodiesel. The two biodiesel production methods that were used are acid-catalyzed esterification followed by alkali-catalyzed transesterification and lipase catalyzed transesterification. It was found that the high level of free fatty acids (FFA) in the coffee oil was reduced from 16.3% to 2.64% by acid-catalyzed esterification with 40/1 molar ratio of methanol to FFA in the presence of 5% (v/v, based on FFA) hydrochloric acid. However, poor conversion was obtained for the further alkali-catalyzed transesterification. In comparison, 98.5% conversion was achieved by using enzymatic catalysis, demonstrating the feasibility of using this approach to process low quality coffee oil from spent coffee grounds for biodiesel production.

Biodiesel From Waste Cooking Oil: Optimization of Production and Monitoring of Exhaust Emission Levels From its Combustion in a Diesel Engine

“…Biodiesel synthesized from edible and non-edible oils, waste cooking oils, and animal fats, has been proved to be a potential alternative to petro-diesel. In the recent years, various attempts have been made by various researchers to explore new advancements in biodiesel production process (Burton et al 2010;Demirbas 2007;Fan et al 2010;Kafuku and Mbarawa 2011;Malça and Freire 2009;Mustafa Özcanl, Keskin, Aydın 2011;Satyanarayana and Muraleedharan 2010;Subbaiah and Gopal 2011;Tao et al 2010;Vedaraman et al 2011).…”

An Experimental Investigation of the Effective Parameters on Wet Washing of Biodiesel Purification

“…All these types of oils come from vegetables or animal fat, making it biodegradable and nontoxic (Marchetti, Miguel, & Errazu, 2007). In the biodiesel production process, different types of catalysts, such as alkali catalysts, acidic catalysts and enzymatic catalysts, are used (Burton, Fan, & Austic, 2010;Mumtaz et al, 2012;Parida, Sahu, & Misra, 2012;Satyanarayana & Muraleedharan, 2010). However, the alkali catalysts are used mainly in industry, because they improve the transesterification rate especially under moderate reaction conditions (Freedman, Pryde, & Mounts, 1984).…”

Biocatalytic Production of Biodiesel from Spent Coffee Grounds

“…The oil that can be recovered from spent coffee grounds is approximately 15 wt% [5]. With a high conversion to biodiesel through transesterification processes, it could add 1 million tons of biodiesel to the transportation fuel supply [1,4]. Due to its high antioxidant content, biodiesel produced from spent coffee grounds has better stability compared to other sources as feedstock [5].…”

“…Biodiesel is seen as an environmental friendly fuel as it holds some advantages over fossil diesel fuel [4]. These advantages include that biodiesel is a renewable fuel, biodegradable, non-toxic and can be blended with fossil diesel fuel.…”

“…Disadvantages of acid-and alkali-catalyzed reactions are: high energy requirements, difficult recovery of catalyst and glycerol, it is toxic and corrosive [4,10]. As an alternative lipase can be used for biodiesel production to overcome the limitations of chemical catalysts: since lipases can be used under moderate conditions, easy to recover, moisture and free fatty acid tolerant [2].…”