Sustainable Fuels, Sealing Solutions and Unlocking Progress in the Energy Transition

As the world shifts towards a sustainable energy future, the transition to renewable sources is more vital than ever. Fuels like biodiesel, biogas, methanol, ammonia and sustainable aviation fuel (SAF) are crucial to achieving net zero emissions goals. It's possible for these fuels to decarbonise hard-to-abate sectors, thereby minimising environmental impact.

Several types of sustainable fuels are significant to unlocking the new energy landscape, each playing a role based on their advantages and limitations. Engaged in more than 30 sustainable fuel projects globally, John Crane is committed to reducing greenhouse gas (GHG) emissions by providing advanced sealing and filtration solutions for rotating equipment across the sustainable fuels value chain.

Defining Sustainable Fuels

Sustainable fuels include biofuels (biodiesel, biogas and ethanol) and e-fuels obtained from electrolytic hydrogen and biologically sourced methanol and ammonia. When used to replace traditional fossil fuels in combustion engines, these sustainable fuels contribute to decarbonisation.

Sustainable biofuels in the form of diesel, gas or ethanol can be classified by “generation”, which reflects their source material and level of technological development.

First Generation: Fuel Produced from Food Crops

Referred to as “first generation,” conventional biofuels are derived from food crops such as corn, sugarcane and soybeans. The primary method for producing first-generation biofuel is fermentation, which breaks down source materials — called feedstock — further and further into carbohydrates, sugars and eventually, ethanol.

Creating biodiesel is similar to creating bioethanol but involves additional steps. It requires vegetable oils, animal fats and specialised processing to extract the oils and combine them to produce a liquid diesel fuel.

Second Generation: Fuel Produced from Non-Food Crops

Biofuels considered second-generation are produced using non-food crops including agricultural waste, perennial grasses, straw, wood chips and/or bagasse — the fibrous material that remains after extracting juice from sugarcane. Because breaking these materials into their constituent components involves greater effort than conventional biofuel crops, the second-generation production process requires complex thermochemical methods. Heat, pressure and enzymes break down the feedstock into component materials. These materials then undergo fermentation, similar to first-generation biofuels.

Production and processing methods for second-generation biofuels are not as mature as those of conventional biofuels. Researchers are working to improve efficiency and develop commercial-scale production.

Third Generation: Algae-Based Fuels

Unlike first- and second-generation biofuels, the third generation uses aquatic algae rather than land crops as feedstock. Algae quickly proliferate in saltwater or freshwater, producing oils and biomass to create biofuels.

Making biogas or biodiesel from algal feedstock involves sophisticated thermochemical processes such as pyrolysis, which is combustion in the absence of oxygen, or hydrothermal liquefaction, which uses heat and pressure to initiate feedstock decomposition.

Fourth Generation: E-Fuels

A fourth generation of sustainable fuels, sometimes called e-fuels, represents a significant advancement over the previous generations. E-fuel does not rely on biological feedstock; instead, it uses low-carbon or renewable energy sources in its production processes.

Generating e-fuel involves combining hydrogen and CO₂ to create a liquid energy carrier. The process for creating e-fuel is at the forefront of innovation, using Fischer-Tropsch synthesis to combine low-carbon hydrogen and CO₂ (often from carbon capture) at high pressure in the presence of a catalyst. The result is a synthetic liquid that can replace fossil fuels in many applications. Research into e-fuel is ongoing, with large-scale production methods in development.

Liquefied Natural Gas (LNG)

LNG burns cleaner than coal or oil and is a bridge fuel in the transition to biofuels and e-fuels. This capability is especially relevant in the marine shipping industry, where high carbon-emitting heavy fuel oil (HFO) combustion typically powers engines. Transitioning from conventional fuels to LNG can help reduce carbon emissions, while sustainable fuel technologies advance to meet demands.

Sustainable bio-LNG — produced from first-, second- or third-generation biofuel feedstock — and e-LNG present exciting decarbonisation solutions. They can leverage existing storage and transportation networks, thus enabling a smooth transition away from fossil fuel-based LNG.

John Crane has experience supporting applications involving sustainable fuels such as LNG, methanol and hydrogen. Learn how our integrated solutions helped a leading shipping company increase the reliability of a sustainable fuel-powered container ship.

The Role of Biofuels in the Energy Ecosystem

Biofuels offer a distinct contribution to decarbonisation, as they can cut emissions in cases where electrification is challenging. As a drop-in alternative to traditional fossil fuels, biofuels can often be used with existing combustion machinery with little-to-no modification. These benefits underscore the role of sustainable fuels in decarbonising the energy ecosystem.

Reducing Greenhouse Gas (GHG) Emissions

Implementing biofuels that lower GHG emissions is an important step toward offering an alternative to fossil fuels. At the point of use, options including sustainable methanol and ammonia emit little to no GHGs compared to traditional fossil fuels.

John Crane is committed to developing innovative solutions that reduce emissions. Learn how a natural gas liquid extraction plant decreased emissions by 97% by switching to John Crane's dry gas seals.

Supporting the Energy Transition

Scaling up low-carbon energy sources is fundamental to a net zero scenario. However, renewables that provide zero-carbon energy are also inherently intermittent. Biofuels can complement renewable energy sources by providing power during downtime intervals when solar and wind cannot meet demand.

Another advantage of biofuels is their ease of storage and transportation; the infrastructure and technology required are well understood. By supporting on-demand energy use, gaseous and liquid biofuels can strengthen security and reliability within the overall energy ecosystem.

Diverse Applications

The transportation sector, which is notoriously difficult to abate, stands to achieve meaningful carbon reductions by incorporating biofuels. Although not yet widely adopted, the production of biofuels for road transport has been well established. The aviation industry is working toward commercialising alcohol-to-jet SAF using bioethanol.

Other biofuel applications involve using biomethane in place of conventional methane for power generation, residential heating or as a feedstock for industrial processes.

Challenges with Biofuel Implementation

While biofuels present a promising pathway to limiting emissions, challenges still hinder adoption. These obstacles involve scientific limitations and market dynamics that impede biofuel use on a larger scale.

Technical Challenges

The IEA estimates that meeting net zero targets will require significant biofuel production. However, securing feedstock for biofuel production is a sensitive issue. First-generation biofuel crops compete with food sources, with limited arable farmland and water resources leading to the option of “food versus fuel.”

Second-generation biofuel feedstock does not come from food crops and can be grown on marginal land. However, the processes for creating biofuel from second-generation feedstock are not as efficient as first-generation biofuels; these methods cost more and produce less.

Producing third-generation biofuels from aquatic algae does not impact land crops, yet scaling up algae farms has proven difficult. The technology for creating biofuel from algae is currently less efficient than both first- and second-generation processes.

Market and Regulatory Trends

Since biofuels are more costly than conventional fossil fuels, advanced economies are more likely to embrace adoption. Policies that prop up biofuels could help overcome this imbalance and drive demand. For example, financial incentives and regulations for producing and blending biofuels would benefit decarbonisation and energy security in both advanced and emerging economies.

According to a projection report by McKinsey, the global biofuel market will increase through 2050 in sectors such as road transportation, aviation, building and industry applications, and maritime shipping.

The Role of Sealing Solutions in the Sustainable Fuel Value Chain

A successful transition to sustainable alternatives is largely contingent upon the technologies that underpin the energy value chain. Among these, sealing solutions play a crucial role. They're key to the integrity and efficiency of rotating equipment — pumps, compressors, expanders and mixers — needed for processing and distribution.

John Crane's Sealing Technologies and Service Capabilities

John Crane's sealing solutions help reduce emissions, increase efficiency and extend the mean time between repair (MTBR) for rotating equipment.

Our global service network is backed by decades of technical expertise. We provide mechanical seal maintenance and repair, mechanical seals reliability programmes, comprehensive asset management solutions and other consultancy-based services that help customers strengthen every link in their value chain.

John Crane's technology has been at the forefront of mechanical sealing for more than 100 years. Our solutions, which support new energy and sustainable fuel initiatives worldwide, include:

• Dry gas seals, including mechanical seals specifically designed for turbomachinery
• Pump seals, including advanced duty mechanical seals for corrosive, viscous or abrasive fluids
• Vessel and agitator seals specialised mechanical seals for mixers, reactors, and other types of reaction vessels
• Seal support systems for wet and dry gas seals
• Seal face technologies such as John Crane Diamond® and Upstream Pumping

Supporting the Transition to Sustainable Fuels

Global leaders must consider all available pathways for decarbonisation. Biogas, biodiesel, ethanol and e-fuel are crucial to making meaningful progress in the energy transition. However, scaling up the sustainable fuel value chain requires a partner focused on innovative solutions.

John Crane's market-ready technologies are already helping increase rotating equipment - safety and reliability and efficiency across the sustainable fuel value chain. However, we're also investing in sealing solutions that meet tomorrow's challenges — because that's what it takes to enable the energy transition across hard-to-abate industries.

Contact John Crane to explore how we can help you engineer a better future.