PRODUCTION AND UTILISATION OF BIODIESEL DERIVED FROM WASTE COOKING OIL : A FEASIBILITY STUDY OF ITS APPLICATION IN MARIKINA CITY, PHILIPPINES

Abstract

This interdisciplinary study explores the engineering, environmental, social science, economics and policy perspectives of a novel waste-to-energy programme in Marikina City, Metro Manila, Philippines. In particular, the study aims to determine the technical and economic feasibility of the production and utilisation of biodiesel derived from waste cooking oil (WCO). It also evaluates the environmental implications ofsuch a programme, as well as the legal and political capacities needed for project realisation. Questionnaire surveys, interviews and focus group discussions were carried out to obtain the data needed for environmental, economic and policy analyses. In addition, WCO sample collection and laboratory analyses were conducted to determine the technical feasibility of WCO biodiesel conversion. Two conversion processes (2-step and single step catalysis) were assessed based on the overall quality ofthe biodiesel produced against existing fuel quality standards. In order to assess the environmental implications ofthe programme, the results of a community survey were consolidated and fitted to an existing biodiesel Life Cycle Analysis (LCA) model. This was then modified to approximate the actual life cycle of WCO biodiesel. A standard cost and benefit analysis of several scenarios was also performed using the benefit-cost ratio as the key parameter for comparison. The results of the study show that more than 30,000 litres of WCO can be recovered from both household and commercial sectors of the city every month. This translates to a monthly biodiesel yield of at least 27,000 litres. The chemical properties of the WCO and the resulting biodiesel are similar to that of coconut oil and its Fatty Acid Methyl Esther (FAME) derivative. The results ofthe total FAME yield obtained from the Gas Chromatography Mass Spectrometry (GCMS) analysis reveal that the product of the 2-step catalysis contains more FAME than that of the single-step catalysed process, with a difference of about 16%. This is further supported by the lower kinematic viscosity ofthe product produced by the same process. Hence, the 2-step catalysed process is deemed more desirable on the basis ofFAME yield and potential for emulsion formation. The results of the environmental analysis illustrate that WCO collection can prevent surface and ground water from contamination with WCO and organic food residues. Moreover, the use of WCO biodiesel is expected to reduce annual emissions of CO2, SOx, and PM (unspecified) and PM10 by 1000, 1.60, 025 and 0.1 metric tons respectively. However, NOx is estimated to increase by as much as 1 metric ton per year. The study's economic analysis also reveals that there is a need for government to secure external grants and maintain a WCO recovery efficiency of at least 80% to ensure positive returns, unless the disbursement of community incentives is deferred for a revenue equivalent ofat least a year. In view of the results of the analyses, this study concludes that Marikina City's exemplary public service infrastructure, robust legal system and strong political will puts it in a strong position to pioneer a citywide WCO biodiesel programme in the Philippines.