Optimizing biodiesel production from Madhuca indica oil using marine bacteria as a whole-cell biocatalyst: engine testing and performance analysis

Abstract

Background

The increasing global demand for fuel, driven by the unchecked extraction and consumption of fossil fuels, has intensified the search for sustainable energy alternatives. Recent advancements in biodiesel production techniques highlight the potential of microbial processes. Lipase-mediated whole-cell biocatalysts for biodiesel production offer a sustainable and economical route that eliminates the need for enzyme purification. These biocatalysts use microbial cells that express lipase to catalyze the transesterification of oils into biodiesel. Their good efficiency, reuse, and operational simplicity make them a new promising alternative to green energy solutions.

Result

This work employs the marine bacterial strain Bacillus licheniformis to develop a whole-cell biocatalyst for the enzymatic transesterification process of Madhuca indica oil in order to produce biodiesel. Optimal conditions for achieving a biodiesel yield of 95.3% were identified as a methanol-to-oil molar ratio of 7.5:1 and a catalyst concentration of 30 wt%. The performance and emission characteristics of biodiesel blends MB30 and MB50 were evaluated in comparison to conventional diesel. Results indicated that MB30 and MB50 blends reduced CO emissions by 11.71% and 27.93%, respectively, compared to diesel. Additionally, MB30 showed decreases in hydrocarbon emission (HC) and smoke opacity by 23.53% and 3.02%, respectively, while MB50 exhibited reductions of 36.47% and 15.42%, respectively. The nitrous oxide emission is enhanced while using biodiesel blends MB30 and MB50 by 13.34% and 15.96% respectively.

Conclusion

The analysis indicates the lipolytic activity of this bacterial strain Bacillus licheniformis, is efficient in converting Madhuca indica oil into biodiesel by a sustainable process. The produced biodiesel had better fuel properties and reduced emissions during engine analysis with respect to CO and particulate matter. This further strengthens its potential to be considered a green alternative to conventional fossil fuels. The process will make use of naturally occurring catalytic properties of bacteria and, hence, would be comparatively green and cheap. This brings to note the possibilities that bio-based resources have opened up for cleaner and more sustainable energy production.

Highlights

• This is the first research to use marine bacteria as a whole-cell biocatalyst for the production of Madhuca indica biodiesel.

• The bacterial strain was isolated from a marine sponge Tedania anhelans.

• Parameters for the synthesis of biodiesel were optimized using the RSM approach.

• The maximum yield of biodiesel produced was 95.3%.

• In engine study, the biodiesel blends MB30 and MB50 demonstrate a decrease in CO, HC, and smoke emissions.

Graphical Abstract