Page 39 - AJWEP-22-5

Heterogeneous catalysts for biodiesel production

chemicals, energy, or animal feed requires more study, either through catalyst modification
(iv) Reducing waste through process integration: a or the use of technology for process intensification, such
circular bioeconomy promotes the integration of as co-solvents, microwaves, or ultrasonication.
several processes to maximize resource use and Efficient manufacturing of FAME from natural
decrease waste production, hence increasing system resources has been a primary area of scientific interest.
efficiency. The most efficient technique for producing biodiesel
is transesterification. Heterogeneous catalysts provide
14. Executing life cycle assessment several benefits over homogeneous ones, including the
ability to operate reactors continuously, produce cleaner
Assessing the economic impact of the glycerol, and eliminate the need for alkaline catalyst
transesterification procedure, society, and environment replacement or neutralization. Due to these benefits,
requires incorporating life cycle assessment into the heterogeneous catalysts are a good substitute for FAME
circular bio-economy framework. Using life cycle generation. Temperature, reactor type, oil kind, and the
assessment, Malode et al. recently examined molar ratio of alcohol-to-oil influence the reactivity
439
advancements in the production of biofuels from biomass of solid catalysts. To get high biodiesel yields, these
and their environmental impacts. Future studies should characteristics must be optimized. The possibility for
evaluate how well transesterification processes perform recovery and their dependence on external-surface active
environmentally and look for ways to cut energy use, sites make heterogeneous catalysts an attractive option.
greenhouse gas emissions, and resource usage. The economic viability of biodiesel production varies
significantly across technologies, with conventional
15. Conclusion alkaline-catalyzed transesterification being the most
cost-effective (0.30 – 0.50 USD/L) but sensitive to
Further sustainable and affordable fuel is needed to feedstock quality, while enzymatic (0.80 – 1.50 USD/L)
enhance the manufacturing of biodiesel. Conventional and supercritical (0.60 – 1.00 USD/L) methods offer
catalysis, which usually uses uniform basic catalysts, greater feedstock flexibility at higher costs. Stability
generates a lot of wastewater and has purification remains a critical challenge, as biodiesel’s oxidative
issues, resulting in less consistent biodiesel quality. degradation, accelerated by unsaturated fatty acids, can
In particular, this review focused on heterogeneous lead to sediment formation, an increase in acidity, and
catalysts, exploring their types, synthesis processes, fuel system deposits during storage. To mitigate these
and applications in the generation of biodiesel. issues, antioxidants (e.g., butylated hydroxytoluene,
Clearly, calcination temperature and time have tocopherols) and selective hydrogenation are employed,
a significant impact on catalyst performance. though they add 0.02 – 0.30 USD/L to production cost.
The intrinsic characteristics of biomass-derived Heterogeneous catalysts (e.g., CaO, K O) provide a
2
heterogeneous catalysts promote sustainable methods middle ground (0.40 – 0.70 USD/L) with improved
and demonstrate encouraging triglyceride conversion reusability and reduced soap formation, but their
outcomes. Although a number of reasonably priced tendency to leach metal ions can still compromise long-
catalysts produced from biomass have previously been term fuel stability. Optimizing production methods
investigated, more research is still required to uncover to balance cost and stability, such as using stabilized
other organic entities. nanocatalysts or blended feedstock, is essential for
Converting biomass waste into catalysts promotes enhancing biodiesel competitiveness against petroleum
sustainable catalyst manufacturing and offers an diesel while ensuring reliable engine performance.
efficient waste disposal alternative. The utilization The results imply that catalyst characteristics,
of waste materials and inedible oils in conjunction particularly basicity and acidity, are essential for the
with inexpensive catalysts derived from renewable synthesis of biodiesel. Acidity affects esterification
resources provides a more economical and ecologically activity, but the basicity of the catalyst directly
sustainable means of producing biodiesel. A number correlates with transesterification efficiency, according
of these catalysts have demonstrated catalytic activity to several studies. Better esterification activity results
that is similar to existing ones of commercially sold from higher catalyst acidity. Notwithstanding their
solid catalysts. However, long reaction times and high promise, biomass-derived materials still face a number
temperatures still remain challenges, as they result in of obstacles that call for more studies, including their
higher energy usage. Enhancing catalyst efficiency restricted supply, the high energy costs associated

Volume 22 Issue 5 (2025) 33 doi: 10.36922/AJWEP025130095