By Ifath Arwah, University of Sharjah

Researchers have developed four new high-octane gasoline formulations using renewable fuel additives, reporting improvements in knock resistance, volatility, fuel stability, and combustion-related properties compared with the base gasoline assessed in the study.

The fuels, named HyperFuel-95, HyperFuel-98, HyperFuel-100, and HyperFuel-102, were formulated by blending petroleum-derived components with isopropanol and methyl ester of dimate (MED). The researchers describe the products as hybrid, low-carbon gasoline biofuels designed to bridge renewable-fuel innovation and continued reliance on internal combustion engines while remaining compatible with conventional internal combustion engines.

The study was conducted by scientists from the University of Sharjah’s Research Institute of Sciences and Engineering (RISE) and was published in the journal Thermal Science and Engineering Progress.

According to the authors, the work represents the “first successful development of new hybrid low-carbon, environmentally friendly, high-octane gasoline formulations” spanning four grades: HyperFuel-95, HyperFuel-98, HyperFuel-100, and HyperFuel-102. The study also reports what the authors describe as “the first use of MED, which is made by methoxylating isohexene (dimate), as a gasoline additive.” The highest-grade formulation, HyperFuel-102, was developed with high-performance engines, motorsports, and aviation applications in mind.

Highlighting the novelty of the work, the authors write, "Significant originality is presented in the current work on providing a new propulsion technology for successfully producing new recipes for hybrid low-carbon, eco-friendly, high-octane Hyperbiofuel-derived gasoline, including HyperFuel-95, HyperFuel-98, HyperFuel-100, and HyperFuel-102 by leveraging these refined fuel fractions and renewable petrol additives."

They further note, "These new recipes are not documented in the literature as viable low-carbon high-octane gasoline biofuels." To evaluate their performance, the team subjected the formulations to laboratory tests and compared them with a commercial reference gasoline consisting of 60% reformate and 40% fluid catalytic cracking gasoline by volume.

Renewable additives meet conventional gasoline

The study addresses two interrelated challenges: the environmental impacts of transportation fuels and the gradual depletion of petroleum-based fossil resources. While electric and other non-fossil technologies are expanding, gasoline-powered vehicles continue to dominate much of the global vehicle fleet, creating demand for lower-carbon liquid fuels that can work with existing spark-ignition engines.

To develop the HyperFuel series, the researchers combined gasoline Fischer-Tropsch (GFT), reformate, and light straight-run naphtha (LSRN) with two oxygenated octane boosters: isopropanol and MED. Describing one of the renewable pathways, the authors note that "Waste, vegetables, wood, and algae are just a few of the biomass feedstocks that can be used to make bioalcohols."

The authors identify isopropanol as a promising renewable fuel component, explaining that it “is one of the potential types of bioalcohols, which can be produced from the strongly entrenched ABE (acetone-butanol-ethanol) fermentation technology." MED, meanwhile, is produced by methoxylating isohexene, also known as dimate, using methanol.

Among the blend components, MED emerged as a particularly effective octane booster because of its strong antiknock characteristics. The study reports research and motor octane numbers of 131.5 and 120, respectively, for MED, compared with corresponding values of 117 and 99 for isopropanol.

aboratory testing ranked the components' contribution to antiknock performance, in descending order, as MED, reformate, isopropanol, GFT, and LSRN.
The composition of the fuels changed progressively across the four formulations. As the target octane rating increased, the researchers reduced the shares of the lower-octane GFT and LSRN fractions while increasing shares of MED and reformate. Bio-blend 1, used for HyperFuel-95, contained 15% GFT, 28% LSRN, 17% MED, 25% isopropanol, and 15% reformate. By contrast, bio-blend 4, used for HyperFuel-102, contained 9% GFT, 17% LSRN, 20% MED, 25% isopropanol, and 29% reformate.

According to the authors, these compositional adjustments were intended to strike a balance between petroleum-based and renewable components while improving fuel quality. As they write, "This change in composition suggested a formulation approach to balancing petroleum-based and bio-based fractions for maximum sustainability and efficiency while enhancing fuel characteristics, especially octane performance."

To evaluate the formulations, the researchers employed a range of standardized laboratory tests measuring octane quality, density, vapor pressure, distillation characteristics, hydrocarbon composition, oxidation stability, gum content, and copper corrosion. The authors state that "these test methods collectively optimize gasoline biofuel recipes for high-octane, low-carbon, low-emission petrol surrogates and high performance."

Research Octane Number (RON) and Motor Octane Number (MON) were determined using a Cooperative Fuel Research (CFR) engine under different operating conditions. The researchers repeated each test as needed “to guarantee accuracy and reproducibility” to ensure the reliability of the results.

From laboratory formulation to commercial fuel

The authors present the HyperFuel series as a potential transitional solution for reducing reliance on conventional fossil gasoline while existing internal combustion engines remain in use. Summarizing the results, they write, "The examination of the physical and chemical features of biofuel-derived gasoline blends shows that they meet local regulatory standards while providing maximized performance attributes."

They further note that "when compared to traditional gasoline, the HyperFuel series exhibits superior anti-detonation properties due to its high anti-knocking characteristics." According to the laboratory results, the blends combine familiar refinery streams with renewable oxygenate additives while maintaining high octane ratings, low sulfur and benzene content, oxidation stability, and favorable distillation characteristics.

"The suggested HyperFuel series presents a viable route toward environmentally friendly gasoline substitutes, attaining lower carbon intensity without sacrificing fuel efficiency," the researchers write. They argue that the blends' antiknock properties and controlled volatility make them potentially suitable for contemporary engines and demanding high-performance applications.

The study stops short, however, of demonstrating whether the fuels can be produced at commercially competitive costs or deliver the projected carbon and emissions benefits across their complete lifecycle. Factors such as feedstock sourcing, processing energy requirements, refinery integration, transportation, engine calibration, and real-world combustion could all influence the ultimate environmental and economic performance.

The researchers acknowledge this commercial gap and identify techno-economic evaluation as a critical next step. Further research, they write, will require "a thorough analysis of raw material costs, processing needs, and the viability of large-scale production" to determine whether the proposed hybrid fuels can progress from successful laboratory formulations to commercially viable alternatives.

For now, the four formulations demonstrate that renewable oxygenated additives can be successfully incorporated into carefully balanced gasoline blends while achieving octane grades from 95 to 102. The findings provide an experimental foundation for further engine testing, emissions studies, lifecycle assessment, and refinery-scale evaluations of hybrid gasoline biofuels.