S. Dharma

A perspective on bioethanol production from biomass as alternative fuel for spark ignition engine

The increasing consumption of fossil fuels has led to the development of alternative fuels for the future. Domestic biofuel production and the utilization of alternative fuels can decrease dependency on petroleum oil, reduce trade deficits, reduce air pollution and reduce carbon dioxide emission. Bioethanol is a renewable fuel produced by the fermentation of sugar which is derived from plants such as sugarcane or beet, maize, or cassava etc. However, bioethanol consumption in an engine is approximately 51% higher than gasoline since the energy per unit volume of ethanol is 34% lower than for gasoline. Bioethanol is an oxygenated fuel that contains 35% oxygen, which can reduce particulate matter and NOx emissions caused by combustion of the fuel. Therefore, bioethanol–gasoline blends can significantly reduce petroleum use and GHG emission. In addition, utilization of lignocellulosic materials in bioethanol production is the most viable pathway from an environmental point of view. This paper reviews the current status and technologies involved in bioethanol production and the properties and engine performance from various biomass feedstocks which are the recommended sustainable alternative fuel in the future.

A comparative study of biodiesel production methods for Reutealis trisperma biodiesel

ABSTRACT In this study, three types of biodiesel production methods are compared in order to maximize Reutealis trisperma biodiesel yields and it is found that the best method is esterification-neutralization-transesterification. The optimum methanol to oil molar ratio, catalyst concentration, reaction temperature, and reaction time are also determined from laboratory experiments and modeling using response surface methodology. There is excellent agreement between the predicted and experimental Reutealis trisperma biodiesel yields under optimum process conditions, with a value of 99.23 and 98.72%, respectively. The physicochemical properties of the Reutealis trisperma biodiesel also fulfill the fuel specifications of the ASTM D6751 standard.

Physicochemical property enhancement of biodiesel synthesis from hybrid feedstocks of waste cooking vegetable oil and Beauty leaf oil through optimized alkaline-catalysed transesterification

Recycling waste cooking vegetable oils by reclaiming and using these oils as biodiesel feedstocks is one of the promising solutions to address global energy demands. However, producing these biodiesels poses a significant challenge because of their poor physicochemical properties due the high free fatty acid content and impurities present in the feedstock, which will reduce the biodiesel yields. Hence, this study implemented the following strategy in order to address this issue: (1) 70 vol% of waste cooking vegetable oil blended with 30 vol% of Calophyllum inophyllum oil named as WC70CI30 used to alter its properties, (2) a three-stage process (degumming, esterification, and transesterification) was conducted which reduces the free fatty acid content and presence of impurities, and (3) the transesterification process parameters (methanol/oil ratio, reaction temperature, reaction time, and catalyst concentration) were optimized using response surface methodology in order to increase the biodiesel conversion yield. The results show that the WC70CI30 biodiesel has favourable physicochemical properties, good cold flow properties, and high oxidation stability (22.4 h), which fulfil the fuel specifications stated in the ASTM D6751 and EN 14214 standards. It found that the WC70CI30 biodiesel has great potential as a diesel substitute without the need for antioxidants and pour point depressants.