Elsevier

Renewable Energy

Volume 34, Issue 3, March 2009, Pages 762-765
Renewable Energy

Biodiesel production process optimization and characterization to assess the suitability of the product for varied environmental conditions

https://doi.org/10.1016/j.renene.2008.04.006Get rights and content

Abstract

In this study, both edible (coconut oil, palm oil, groundnut oil, and rice bran oil) and non-edible oils (pongamia, neem and cotton seed oil) were used to optimize the biodiesel production process variables like catalyst concentration, amount of methanol required for reaction, reaction time and reaction temperature. The fuel properties like specific gravity, moisture content, refractive index, acid value, iodine number, saponification value and peroxide value were estimated. Based on the cetane number and iodine value, the methyl esters obtained from palm and coconut oils were not suitable to use as biodiesel in cold weather conditions, but for hot climate condition biodiesel obtained from the remaining oil sources is suitable.

Introduction

The increased use of diesel fuel resulted in depletion of its fossil reserves. This triggers for many initiatives to search for alternate fuel, which can supplement or replace such fossil fuel. In recent years, research has been directed to explore plant-based fuels and plant oils and fats as fuels have bright future [1]. The most common that is being developed and used at present is biodiesel, which is fatty acid methyl esters of seed oils and fats and have already been found suitable for use as fuel in diesel engine. Biodiesel is found to be environmentally safe, non-toxic and biodegradable [2].

The raw material being exploited commercially by the developed countries constitutes the edible fatty oils derived from rapeseed, soybean, palm, sunflower, coconut, linseed, etc. [3]. Use of such edible oil to produce biodiesel in India is not feasible in view of a big gap in demand and supply of such oils in the country. Increased pressure to augment production of edible oil has also put limitation on the use of these oils for production of biodiesel. Under such conditions, those crops that produce non-edible oil in appreciable quantities can be grown in large scale in non-cropped marginal lands and wastelands only considered for biodiesel production [4].

Long list of trees, shrubs and herbs is available plenty in India, which can be exploited for fuel production. In this study we have utilized both edible and non-edible oils for the biodiesel production process optimization and fuel property characterization to assess the suitability of the different methyl esters to the varied environmental conditions.

Section snippets

Materials and methods

Edible (coconut oil, palm oil, groundnut oil, rice bran oil, and gingelly oil) and non-edible (pongamia, cotton seed oil and neem oil) oils were used in this experiment.

All the oils were first filtered by cloth mainly to remove the dirt and other inert materials from the oil and then placed in a conical flask equipped with magnetic stirrer, thermometer and condenser. Under agitation the raw oil was heated up to nearer to the boiling point to remove the water contaminant present in the oil.

Effect of catalyst concentration

The effect of sodium hydroxide concentration on the transesterification of the edible and non-edible oils was investigated with its concentration varying from 0.5 to 2.5 wt.% (based on the weight of raw oil). The operation conditions during the whole reaction process were fixed at the optimal level: reaction temperature of 55 °C, reaction time of 90 min. and 180 and 210 ml of methanol for edible and non-edible oils, respectively.

Experimental results showed changes in ester yield content with varied

Conclusion

The study on the biodiesel production process optimization of edible and non-edible oils showed that the quantity of catalyst, amount of methanol, reaction temperature and reaction time are the main factors affecting the production of methyl esters. The optimal values of these parameters for achieving maximum conversion of oil to esters depended on the chemical and physical properties of these oils. The following conclusions are drawn from the study:

  • Addition of excess catalyst causes more

Acknowledgment

The authors thank Dr. K. Veeramani, Chancellor and Dr. N. Ramachandran, Vice-Chancellor, Periyar Maniammai University for encouragement and research funding.

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