Advances in Sustainable Fuel Materials for Industrial Applications: A Systematic Review ^†

Abstract

The use of fossil fuels in the industry has resulted in a significant environmental impact, contributing to high levels of CO₂ emissions. The growing need for sustainable alternatives has driven research into biofuels, hydrogen, and other renewable energy sources. To address this issue, a systematic review was conducted using the ScienceDirect and Scopus databases, selecting relevant studies published between 2020 and 2024. The PRISMA2020 model and VOSviewer 1.6.20 software were applied for data analysis. The results highlight advancements in biodiesel production from various raw materials, emission reductions in the maritime industry through liquefied natural gas (LNG) utilization, and improved combustion efficiency using hydrogen in industrial engines. It is concluded that technological development and the implementation of environmental policies are essential for a sustainable energy transition.

1. Introduction

Industrial activities generated 9.4 gigatonnes of CO₂ in 2021, representing nearly 25% of global emissions, with the maritime, aviation, and petrochemical sectors as major contributors [1,2,3,4]. This environmental burden is exacerbated by the widespread reliance on fossil fuels, which despite covering 48% of the global energy demand, pose challenges related to pollution, resource depletion, and price volatility. As a response, biofuels—particularly biodiesel from vegetable oils—have emerged as promising alternatives. Biodiesel offers advantages such as cost-effectiveness, biodegradability, low sulfur and aromatic content, and a higher flash point, making it a safer and more sustainable option for industrial applications [5,6].

Recent advancements demonstrate the viability of converting Grewia asiatica seed oil into biodiesel using eco-friendly niobium oxide nanoparticles, achieving a 90% yield under optimal conditions [7]. In Taiwan, the use of biodiesel in industrial boilers has shown promising results, reaching an energy efficiency of 86.6% [8]. Additionally, carbon capture, utilization, and storage (CCUS) strategies, particularly in China, are key to meeting long-term decarbonization goals, aiming for over 80% of the national energy supply from carbon-free sources by 2060 and reducing CO₂ emissions by the same margin [9].

Despite regulatory and technological challenges, sustainable fuel technologies continue to advance across industries. In the context of Industry 4.0, circular supply chain models for electric vehicle batteries integrate robotics, reverse osmosis systems, and emission reduction technologies to promote reusability [10,11]. In Sweden, bioethanol, e-methanol, and hydrogen have been identified as viable low-carbon marine fuels, with biomethanol standing out as the most cost-effective [12]. Additionally, the pyrolysis of biogas digestate has enabled the production of biodiesel blends suitable for agricultural and maritime diesel engines [13].

Butyraceous braunii has emerged as a promising microalga for biodiesel production due to its capacity to synthesize long-chain hydrocarbons, with wastewater serving as a cost-effective growth medium [14]. Additionally, the catalytic deoxygenation (CDO) of biomass, particularly soybean oil using a modified dolomite catalyst (NiO-CD), has achieved high deoxygenation efficiency (88.6%) and produced eco-friendly diesel with a hydrocarbon yield of 50.5%, surpassing conventional catalysts [15]. This review aims to provide a comprehensive overview of developments in sustainable fuels for the industry between 2020 and 2024. It focuses on evaluating production processes, energy efficiency, and CO₂ emission reductions in biodiesel, bioethanol, e-methanol, hydrogen, and liquefied natural gas.

2. Materials and Methods

Through a systematic literature review, the most relevant articles were identified and synthesized in an organized and transparent manner. Initially, two databases were selected, namely ScienceDirect and Scopus. Subsequently, the search was conducted using the keywords “sustainable fuels” and “industry,” applying the logical operator AND. The study was limited to the period between 2020 and 2024, excluding review articles and considering only open access research articles in English, resulting in a preliminary set of 571 articles. Once collected, the articles were exported to Rayyan software, which identified and removed 8 duplicate records. In the initial phase of article selection, only those whose title and abstract contained the predefined keywords were considered. Subsequently, studies focused on renewable energy, politics, economics, chemical concepts, and systematic reviews were excluded, as they did not align with the research focus. As a result of this process, 17 articles were selected, whose synthesis is presented using the PRISMA methodology in Figure 1 [16].

3. Results and Discussion

Table 1. Summary of research on biofuels and their impact on various industries.

No.	Author/Year	Ref.	Fuel Type	Process	Industry	Key Findings
1	Sharma et al. (2022).	[17]	Fish oil (FOEE, FOPE)	Biological–Chemical	Various	Good physicochemical stability among esters.
2	Kirshner et al. (2022).	[18]	2G bioethanol	Biological	Refinery	Relevance of primary crops for enzyme development.
3	De Fournas & Wei (2022).	[19]	Renewable methanol	Physicochemical	Maritime	GHG reduction of 38–165%; integrated with PEM electrolysis.
4	Moghaddam et al. (2024).	[20]	Dimethyl ether (DME)	Chemical	Transport	Compatible with LPG/diesel infrastructure; modified zeolites.
5	Maydison Lim et al. (2024).	[21]	LNG	Physicochemical	Maritime	Reduces global warming potential by 23–42%.
6	Andra Luciana et al. (2021).	[22]	LNG	Physicochemical	Maritime	Identified as the most sustainable marine fuel.
7	Molina et al. (2023).	[23]	Hydrogen	Physicochemical	Transport	Requires air dilution adjustment to control emissions.
8	Baidoo et al. (2022).	[24]	Rubber seed oil	Chemical	Aviation	Viable due to high oil content and comparable properties.
9	Alsiyabi et al. (2021).	[25]	Ethanol E30	Physicochemical	Transport	Feasible in non-flex vehicles; manageable with system calibration.
10	Agarwal et al. (2020).	[26]	Methanol M85	Physicochemical	Transport	More injected fuel needed; engine delivers similar power.
11	Laguado-Ramírez et al. (2024).	[27]	Rice bran biodiesel + H2	Chemical	Various	Reduced pressure with biodiesel; enhanced with H2 blend.
12	Ishola et al. (2020).	[28]	Palm biodiesel	Biological–Chemical	Various	62.5% yield; meets ASTM biodiesel standards.
13	Aravinda et al. (2024).	[29]	LPG + hydrogen	Physicochemical	Various	Improved combustion; reduced CO and CO2 emissions.
14	Rozina et al. (2024).	[7]	Grewia asiatica seed oil	Biological–Chemical	Various	High conversion efficiency; ultra-low sulfur content.
15	Emma et al. (2022).	[30]	Coffee husk biodiesel	Biological–Chemical	Various	Blends improve calorific value and reduce viscosity.
16	Kourkoumpas et al. (2024).	[31]	Used vegetable oil (HVO)	Physicochemical	Petroleum	7.7% GHG reduction with HVO integration.
17	Mors et al. (2023).	[32]	Bio-oil from organic waste	Chemical	Aviation	79% C8–C16 fraction; suitable for aviation biofuel.

presents an analysis of 17 studies on sustainable fuels, highlighting biodiesel, bioethanol, renewable methanol, hydrogen, and liquefied natural gas (LNG) as viable options for reducing industrial emissions. The research primarily focuses on applications in the transportation, aviation, and maritime sectors.

In aviation, sustainable aviation fuels (SAFs) offer lower carbon emissions compared to conventional fuels [33]. Studies explored rubber seed oil for biodiesel production through hydrogenation simulations [24] and organic waste liquefaction—such as mandarin peels, coffee grounds, and cocoa husks—for sustainable fuel synthesis [32]. The transportation sector has investigated hydrogen, ethanol, and methanol as promising alternatives. Methanol dehydration for dimethyl ether (DME) has demonstrated compatibility with existing LPG and diesel infrastructure [20]. In India, an M85-fueled motorcycle improved efficiency but generated higher NOx emissions [26]. Another study in the U.S. found that increasing E10 to E30 usage in 10% of vehicles annually could significantly impact emissions [25]. Hydrogen integration in spark ignition engines, with concentrations of 25–75%, was shown to reduce greenhouse gases and pollutants [23]. In maritime applications, biomass gasification for methanol production led to a 38–165% reduction in greenhouse gas emissions compared to traditional fuels [19]. LNG substitution in a training vessel reduced global warming potential by 23.1–42.3% [21]. A comparison of LNG and petroleum-based marine fuels confirmed LNG as the most sustainable option [22].

Beyond these industries, biomass utilization for bioethanol production—such as eucalyptus-derived enzymes in Brazil—offers new solutions [18]. Hydrogen–LPG mixtures in commercial burners were found to improve combustion efficiency while reducing CO and CO₂ emissions [29]. Spain’s ceramic tile industry evaluated negative-emission biohydrogen Hydrogen-coupled Bioenergy with Carbon Capture and Storage (HyBECCS), which enhanced biomethane savings by over 37% compared to conventional gas blends [34]. In the aviation sector, recent studies emphasize that Sustainable Aviation Fuels (SAF) combined with carbon capture can achieve negative emissions and high carbon efficiency, providing a critical roadmap for decarbonizing long-haul transport [35]. Complementing this, novel catalytic processes, such as palladium-on-carbon-catalysed reactions using cyclohexanone and alkyl alcohols, are being developed to synthesize jet fuels with zero net emissions [36].While emission reduction strategies vary across sectors [37], the aviation industry remains a major contributor to climate change [38], driving sustainable fuel advancements [39]. Renewable energy sources—including biodiesel, e-methanol [40], photovoltaics [41], industrial solar heating [42], and hydrogen—are gaining traction. Europe is progressing with pilot projects, positioning itself for future expansion [43]. This review underscores a preference for biological feedstocks in biodiesel production, including fish oil [17], rice bran [27], coffee husks [30], palm olein [28], rubber seeds [24], Grewia asiatica [7], and used cooking oil [31]. Chemical processing enhances their physicochemical properties, reinforcing their viability as alternatives to fossil fuels. Regulatory and infrastructural challenges persist, but ongoing research and policy support could accelerate sustainable fuel adoption across industries.

Figure 2 illustrates the keyword co-occurrence network extracted from the Scopus database for 2020–2024 on sustainable fuels. It shows a central core dominated by large red nodes such as “sustainable development”, “climate change”, “renewable energy”, and “carbon”, indicating high frequency and centrality in the literature. Surrounding this, a medium-sized green cluster groups terms such as “energy efficiency” and “global warming”, focusing on energy optimization and emissions mitigation. A third yellow group with moderate-frequency nodes includes “greenhouse gases” and “life cycle assessment”, focusing on environmental assessment. Finally, smaller blue nodes such as “fossil fuels” and “biofuels” mark emerging subthemes. The strong interconnections between terms suggest a multidisciplinary approach encompassing chemical engineering, sustainability, and renewable energy. Previous studies have emphasized the significance of these connections in optimizing biomass conversion and reducing carbon emissions [7,44]. Thus, analyzing this figure helps identify crucial areas for technological advancements in biofuel development. Figure 3 illustrates the network of the most cited authors and co-authors in biofuel research from 2020 to 2024, providing insights into academic collaboration within the Scopus database. The size of each circle is proportional to the number of citations, indicating a relatively similar citation count among most researchers. However, How B. S. stands out as the most cited author, as their circle is slightly larger than the others, suggesting a significant impact in the field. The connectivity among authors highlights interdisciplinary collaborations between institutions and research groups, reinforcing joint efforts to advance sustainable energy technologies [45]. The presence of clusters within the network indicates specific areas of research interest, such as biodiesel and bioethanol production, environmental impact analysis, and biochemical process optimization. Previous studies have emphasized the importance of academic collaboration in improving biofuel production processes and increasing biomass conversion efficiency [46,47].

The co-authorship map for the period 2020–2024, generated with VOSviewer, reveals a stratified structure where the nodes represent individual authors. In the center, the largest red nodes, identified as Lim, C. H. and Sunarso, J., indicate the researchers with the highest number of collaborations and high centrality within this specific dataset. Surrounding them, a medium-sized green group, composed of nodes such as How, B.S. and Ng, W.P.Q., groups studies on biomass conversion and microbial culture optimization.The smaller blue nodes, associated with Lam, H.L. lam and Teng, S.Y., reflect emerging collaborations in green hydrogen technologies and energy carriers, which are still in the consolidation phase. Finally, a moderately sized yellow cluster, featuring Yeoh, S., and Show, P.L., integrates interdisciplinary studies on life cycle assessment and sustainability.

Furthermore, global author connectivity suggests growing international cooperation, facilitating knowledge exchange and technological advancements in renewable energy solutions. This visualization underscores the increasing integration of scientific research in addressing energy challenges and accelerating the transition to sustainable alternatives. Understanding these connections provides valuable insights into emerging trends, influential contributors, and collaborative dynamics shaping the future of biofuels, reinforcing the importance of integrated scientific efforts in achieving global energy sustainability [48].

Future Research Trends: The field of sustainable fuels is moving toward the diversification of non-conventional feedstocks, such as microalgae and industrial waste, optimized through next-generation heterogeneous catalysts and integrated biorefinery processes [14,30]. Likewise, the convergence of digital technologies under Industry 4.0 paradigms, including artificial intelligence and big data analytics, will enhance the efficiency of review protocols and the performance prediction of new fuels [43]. Research into electrochemical fuels (e-fuels), especially e-methanol and e-hydrogen, supported by Power-to-X schemes and CO₂ capture, is expected to grow [43]. Furthermore, the development of life cycle assessment methodologies and full-scale techno-economic analyses will promote the commercial viability of these solutions [48]. Finally, the implementation of global and transversal collaboration networks and incentive policies will be key to accelerating the energy transition towards net-zero climate emissions.

4. Conclusions

The adoption of sustainable fuels—such as biodiesel, bioethanol, e-methanol, hydrogen, and LNG—is crucial for reducing industrial CO₂ emissions and improving energy efficiency. The analyzed studies demonstrate that adopting these fuels can significantly reduce the carbon footprint, enhance energy efficiency, and optimize industrial processes. However, challenges persist regarding infrastructure, production costs, and regulatory acceptance. While these alternatives show clear environmental and operational benefits, their widespread implementation faces challenges related to infrastructure, costs, and regulation. Advancements in technologies like CCUS and catalytic processes, along with supportive policies and research investment, are essential to enable an effective and sustainable energy transition.