ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Critical review on quality, stability and uses of fuel additives for biodiesel

Shajia Rehman, Fawad Ahmad, Waqar Uddin, Mohamed A. Habib, Ahmed B. M. Ibrahim, and Mudassir Iqbal

Department of Chemistry, University of Wah, Quaid Avenue, Wah Cantt, Punjab, Pakistan

E-mail: fawad.ahmad@uow.edu.pk

Abstract:

The performance limitations of conventional and bio derived diesel fuels, particularly poor oxidative stability, cold flow behavior and emission profiles, have intensified the need for effective fuel additives. This review critically evaluates major classes of additives, including antioxidants, cold flow improvers (CFIs), lubricity improvers, cetane enhancers and multifunctional formulations, with main focus on their performance consistency across diverse feedstocks. Comparative analysis reveals that antioxidant additives, particularly phenolic and aminic compounds, demonstrate the most reliable improvement in oxidative stability across all feedstocks. CFIs shows strong feedstock dependence, performing most effectively in paraffinic rich diesel but they exhibit reduced efficiency in biodiesel dominant blends. Cetane enhancers consistently improve ignition quality with relatively low dosage requirements, although their impact on emissions varies with engine conditions. Lubricity improvers are found to be essential for ultra-low sulfur diesel (ULSD), where sulfur removal compromises inherent lubricity, while multifunctional additives offer synergistic benefits but they also have antagonistic interactions under certain conditions. A key contribution of this review lies in integrating performance trends with feedstock chemistry, additive concentration and operational parameters, to identify practical optimization, rather than isolated outcomes. The analysis highlight that no single additive class is universally optimal, instead tailored additive combinations are necessary to balance operability, stability and environmental performance. This work establishes an integrated framework for the rational selection and design of fuel additive systems, and also highlight the emerging directions, to expedite the development of next generation fuel additives.

Graphical abstract

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05110-y

Chemical Papers 80 (11) 12615–12650 (2026)