F. Kusumo

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.

Optimization of extraction of lipid from Isochrysis galbana microalgae species for biodiesel synthesis

ABSTRACT Microalgae are promising alternative plant sources for biodiesel production because of the significant increase in lipid yield through heterotrophic cultivation and genetic engineering approaches. This study aims to evaluate the extraction and conversion of lipids from Isochrysis galbana. Response surface methodology (RSM) was used to optimize lipid extraction and thereby obtain high yields from the four microalgae species. The optimal lipid yields for Isochrysis galbana is 8.41 wt%. Moreover, the dominant lipid composition found from Isochrysis galbana extractions was palmitic acid (C16:0) at 22.3%. The high saturated acid of Isochrysis galbana contributed to the improved biodiesel properties because biodiesel quality is influenced by the lipid composition of microalgae species. The study employed the two-step esterification–transesterification process to convert the microalgae oil into biodiesel, glycerol, and water. The FAME content is 99.7% under the methanol to oil molar mass of 12:1, 1 wt%, 65°C, and 800 rpm. Furthermore, the main biodiesel properties, such as viscosity, higher heating value, and iodine value, were measured according to ASTM D6751 and EN 14124. Results show that microalgae oil can potentially be used as biofuel in future applications.

A comparative study of ultrasound and infrared transesterification of Sterculia foetida oil for biodiesel production

ABSTRACT In this study, biodiesel production using ultrasound and infrared techniques is introduced. The ultrasound and infrared techniques are more efficient for biodiesel production since they improve the mass transfer between the immiscible reactants, increase chemical reactions, and decrease the reaction time and energy consumption. The effect of the reaction time on the acid value of the esterified Sterculia feotida oil is also investigated and it is found that the acid value is 0.76 and 0.85 mg KOH/g for the ultrasound and infrared technique, respectively, at a reaction time of 60 min. In addition, it is found that the biodiesel yield obtained from the ultrasound technique is higher (99.41%) compared to the infrared technique (98.55%) at a reaction time of 60 min. The KOH catalyst is analyzed for both of these techniques and it is found that the ultrasound technique gives faster absorbed reaction compared to the infrared technique. Hence, it can be concluded that the ultrasound and infrared transesterification techniques are promising techniques for biodiesel production.

Analysis of the performance, emission and combustion characteristics of a turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends using kernel-based extreme learning machine

The purpose of this study is to investigate the performance, emission and combustion characteristics of a four-cylinder common-rail turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends. A kernel-based extreme learning machine (KELM) model is developed in this study using MATLAB software in order to predict the performance, combustion and emission characteristics of the engine. To acquire the data for training and testing the KELM model, the engine speed was selected as the input parameter, whereas the performance, exhaust emissions and combustion characteristics were chosen as the output parameters of the KELM model. The performance, emissions and combustion characteristics predicted by the KELM model were validated by comparing the predicted data with the experimental data. The results show that the coefficient of determination of the parameters is within a range of 0.9805–0.9991 for both the KELM model and the experimental data. The mean absolute percentage error is within a range of 0.1259–2.3838. This study shows that KELM modelling is a useful technique in biodiesel production since it facilitates scientists and researchers to predict the performance, exhaust emissions and combustion characteristics of internal combustion engines with high accuracy.

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.