Governments, corporations, and consumers alike are demanding alternatives to fossil fuels that can reduce emissions, enhance energy security, and support the urgent push toward net zero. Among the most prominent contenders in this transition are biofuels, particularly biodiesel (FAME) and hydrotreated vegetable oil (HVO).
As with all energy solutions, biofuels come with both opportunities and challenges. Their chemistry makes them a beacon of sustainability but also introduces the need to consider any operational risks, notably the potential for microbial contamination. Understanding these dynamics is key – to not only embrace the promise of biofuels, but to manage them effectively in order to deliver their full potential.
Conidia Bioscience, a company that develops and manufactures innovative solutions for fuel system maintenance, has evaluated the leading transition contenders in laboratory conditions. In this article they share the outcomes, exploring the reasons behind surging demand for biofuels, why HVO is poised to lead the charge, and how careful vigilance and good fuel management can help to ensure successful adoption.
Why biofuels are surging
The case for biofuels is both environmental and pragmatic. Unlike fossil fuels, which release carbon that has been sequestered underground for millions of years, biofuels can operate within a closed carbon cycle. The CO₂ emitted during combustion is offset – at least in part – by the CO₂ absorbed during the growth of the biomass feedstocks, whether those are sugarcane, corn, soy beans, or waste fats.
Biofuels also offer something many renewable technologies struggle with: Compatibility. Whereas electrification requires new infrastructure, and hydrogen demands new distribution networks, biofuels can often flow seamlessly into existing engines and supply chains.
Market forecasts tell a clear story. Today, biofuels account for a small slice of global energy demand, but their share is expected to double to 6% by 2030. Transport fuels will be the largest driver, with biofuels meeting roughly 9% of demand within the decade. Aviation, traditionally a hard-to-abate sector, is set for even faster growth, with sustainable aviation fuel (SAF) expected to cover 10% of demand by 2030.
Behind the statistics lies a powerful narrative: biofuels are no longer niche. They are climbing the energy ladder into mainstream relevance.
The two faces of biofuels: FAME and HVO
Not all biofuels are created equal. Two, in particular, dominate the diesel-replacement conversation: biodiesel (FAME) and hydrotreated vegetable oil (HVO).
FAME: A double-edged sword
Biodiesel, technically known as fatty acid methyl ester (FAME), is derived from vegetable oils, animal fats, or recycled greases. It is widely used in blends (B7, B20, or even B100), and on paper, it represents a renewable, sustainable solution.
But FAME carries vulnerabilities, especially around water. Research shows biodiesel can hold 15 to 25 times more water than conventional diesel, creating favourable conditions for microbes. This hygroscopic nature, combined with biodiesel’s oxygenated chemistry, means that microbial contamination can quickly become a problem in storage and distribution systems.
HVO: The drop-in disruptor
HVO, by contrast, is structurally different. Produced by hydrogenating vegetable oils or animal fats, it emerges as a paraffinic hydrocarbon that looks and behaves remarkably like petroleum diesel.
The implications are profound:
- HVO contains no oxygen, making it less prone to oxidation and microbial attack.
- It has low water affinity, behaving more like fossil diesel in storage.
- It burns cleaner than biodiesel.
- It requires no engine modifications as a drop-in fuel.
HVO’s stability is another strength. Properly stored, it can last up to 10 years, compared to biodiesel blends that often degrade within months. For fleet operators, shipping companies, and backup power providers, this long shelf life is a game-changer.
It is little wonder, then, that HVO adoption is expected to accelerate sharply over the next decade. As governments tighten emissions targets and industries seek practical decarbonisation tools, HVO stands out as a bridge between today’s infrastructure and tomorrow’s sustainability goals.
The microbial challenge: Water, biofilms, and breakdown
Biofuels may be renewable, but they are also biologically inviting if conditions align. Microbes are omnipresent in the environment, lying dormant until fuel, water, and time create an opportunity.
How water sneaks in
Water infiltrates storage tanks through multiple pathways:
- Condensation from temperature fluctuations.
- Leaks through corroded fittings or poor seals.
- Hygroscopic absorption, particularly in biodiesel.
Once inside, water stratifies. Free water pools at the tank bottom, while emulsified water disperses throughout the fuel. Both forms create risks. Warmer temperatures increase water solubility, feeding microbial growth, while colder conditions reduce – but never eliminate – the threat.
Biofilms: The hidden saboteurs
When microbes encounter fuel-water interfaces, they form biofilms – sticky, gelatinous layers composed of polysaccharides, proteins, and lipids. These biofilms cling to tank surfaces, clog filters, corrode metal, and degrade fuel quality.
The risk lies in their resilience. Microbes in biofilms can be up to 1,000 times more resistant to biocides than free-floating cells. Once established, they are notoriously difficult to eradicate, requiring both chemical and physical intervention.
For operators, the consequences can be significant: pump failures, nozzle fouling, sluggish servo-valves, engine stalling, and corrosion of tanks and pipelines, all of which can be costly and disruptive if not addressed. In sectors where uptime is critical – aviation, shipping and emergency services – operational reliability is essential.
Laboratory lessons: Testing the limits
To better understand these risks, Conidia Bioscience evaluated FAME, HVO, and SAF in controlled laboratory conditions. Fuel samples were inoculated with a blend of common microbial species, then monitored over several weeks.
The results confirmed what industry has long observed:
- FAME is highly susceptible to microbial growth, owing to its chemistry and water affinity.
- HVO is far more resistant, though not immune, particularly when excess water is present.
- SAF sits between the two, with risks dependent on storage and handling conditions.
To monitor such threats in the field, rapid lateral-flow tests have been developed that can detect biomarkers of microbial presence and biofilm formation.
Conida’s solution, FUELSTAT® One is an example of how technology is supporting operators in balancing sustainability goals with operational reliability. Unlike traditional culturing, which can take days, this tool delivers results in 20–30 minutes using a simple test kit and a smartphone app.
Managing the microbial risk
Mitigating microbial contamination is not about eliminating microbes – an impossible task – but about controlling the conditions that allow them to flourish.
The first line of defence: Water control
Keeping tanks dry is paramount. This means:
- Regularly draining free water.
- Maintaining seals and gaskets to prevent ingress.
- Using water-removal technologies that can absorb emulsified water before microbes can exploit it.
Testing and monitoring
Routine testing is the second safeguard. Rapid diagnostics like FUELSTAT® allow operators to catch contamination early, before biofilms harden into entrenched problems. By embedding such checks into regular maintenance schedules, operators can reduce downtime, extend equipment life, and minimise costly cleanups.
The strategic context: Beyond chemistry
The biofuels story is more than a technical debate over molecules and microbes. It reflects a deeper question: how do we decarbonise without disrupting the backbone of global mobility and trade?
Electric vehicles dominate headlines, but they will not power container ships across oceans or aircraft across continents anytime soon. Hydrogen holds promise but faces infrastructure bottlenecks. Nuclear and renewables are reshaping power grids, not diesel engines.
In this landscape, biofuels – particularly HVO – offer immediacy. They leverage existing infrastructure, reduce lifecycle emissions, and buy time for the broader energy transition. But success depends on ensuring that any vulnerabilities are acknowledged and addressed. Microbial contamination is one such issue; it is an operational risk that requires proactive management to deliver full confidence in biofuels.
Conclusion: A fuel for the future, if we get it right
Biofuels stand at a crossroads. On one side lies enormous promise: carbon savings, energy security, compatibility with today’s infrastructure. On the other lies a microbial challenge, that became apparent during early FAME adoption. Left unchecked, it could undermine reliability and slow adoption – but with proper management, it is highly controllable.
The rise of HVO suggests the market is learning fast – prioritising fuels that balance sustainability with stability. But even HVO requires the good fuel management that has always been an essential aspect of the industry and continues to be so with biofuels. Vigilance in water management, routine testing, and investment in contamination-control technologies will be essential to keep renewable fuels clean, engines running, and the energy transition on track.
The energy transition will not be won in laboratories or policy papers alone. It will be secured in the real-world storage tanks, pipelines, and engines where fuels meet microbes. There is no question whether biofuels will play a role in the future of energy – they already are. The challenge now is to manage them effectively so that they can deliver fully on their promise.
To find out more about biofuels, HVO and blends, download Conidia Bioscience’s latest free white paper here: https://conidia.com/biofuels-hvo-and-blends/
Image credit: Conidia Bioscience
