Here’s to the Alternatives to the Alternatives: LNG, Methanol Duel It Out at Sea

by Jim Lane (Biofuels Digest) ... what should power the boat? The current answer is a sprawling, contested catalogue of contenders—conventional LNG, Bio-LNG, biomethanol, e-ammonia, hydrogen, and wind-assisted propulsion. The real challenge,however, is not simply dreaming up a cleaner molecule. It is inventing an industrial architecture that can manufacture,transport, store, and bunker that molecule without bankrupting the voyage. That reality takes us to two very different industrial doctrines, both starting with the exact same unpretentious, volatile molecule: methane.

The Swedish Play: Economies of Aggregation

Our first port of call is Vara, located within Sweden’s agricultural heartland of Västergötland, northeast of Gothenburg.Here, roughly one hundred farmers have united under Biogas Västra Skaraborg AB to resolve a dilemma as ancient as agriculture itself: what to do with the manure. Returning slurry to the soil remains sensible agronomy until volumes,seasonal nutrient limits, and regional runoff mandates turn it into an environmental tightrope. Rather than treating animal waste as a disposal liability, these Swedish growers decided to construct an industrial assembly line.

Partnering with German technology specialist EnviTec Biogas, their joint facility is engineered to digest approximately 370,000 tonnes of cattle and swine manure, slurry, and agricultural residues annually—more than a thousand tonnes of feedstock arriving at the gate every single day. The operational blueprint calls for generating up to 70 gigawatt-hours of upgraded biomethane each year, piped immediately into a contiguous liquefaction train to yield Bio-LNG for heavy transport and marine bunkering.

EnviTec’s EnviThan hollow-fiber membrane systems strip away the carbon dioxide,sending pipeline-spec biomethane directly into an adjoining liquefaction unit without the overhead of intermediary regional pipeline transport.

The Massachusetts Venture: The Engine as a Chemical Plant

Now turn west across the Atlantic to Woburn, Massachusetts, where MIT spinout Emvolon is looking at the vast universe of methane that slips through the fingers of traditional energy infrastructure. The gas escaping from small municipal landfills, remote manure pits, isolated wastewater systems, and flared oilfield gathering lines has always suffered from an awkward economic reality: there is plenty of total energy, but never enough concentrated in one postal code to justify a hundred-million-dollar chemical complex. Building a sprawling refinery next to a modest landfill is the economic equivalent of dredging a deep-water seaport for a duck pond. Gathering that dispersed gas with long-distance pipelines and compressor stations rapidly incinerates capital. So, Emvolon turned the proposition completely on its head: instead of building expensive gathering infrastructure to haul the gas to the factory, why not build a factory that can drive out to the gas?

Operating under fuel-rich, partial-oxidation conditions, the modified engine reforms methane-rich waste streams into synthesis gas—a balanced stream of carbon monoxide and hydrogen—while preserving the chemical energy of the molecule. That syngas is routed through downstream catalytic synthesis modules to condense into liquid biomethanol. Yesterday, the engine moved a semi-truck; today, it operates as a modular chemical plant manufacturing fuel to propel a container vessel. By hijacking mature automotive manufacturing supply chains and known maintenance tolerances, Emvolon sidesteps the bespoke fabrication bottlenecks that habitually plague first-of-a-kind chemical engineering projects.

Methanol, by contrast, is a liquid at ambient temperature and atmospheric pressure. While toxic and demanding vigilant maritime handling protocols, it moves effortlessly within standard chemical tankers, tanker trucks,and rail cars. The Swedes move the raw biomass to generate liquefied gas; the Americans move the plant to turn dispersed gas into ambient liquid.

That distributed logic just attracted serious capital. Emvolon secured $22 million in Series A equity and grant funding backed by MassVentures, VX Ventures, and Wagner Carbon to scale its skid-mounted modules.

Bio-LNG slots directly into the existing maritime infrastructure developed for fossil LNG, delivering high energy density and proven dual-fuel engine architectures. Yet LNG demands complex vacuum-insulated, cryogenic bunker tanks,continuous boil-off gas management, and hyper-vigilance against engine methane slip, which can wipe out carbon benefits. Biomethanol sidesteps cryogenics entirely, resting comfortably in mildly modified bunker tanks at sea level,but it carries a lower volumetric energy density that requires roughly twice the fuel storage volume for an equivalent voyage. Both pathways deliver a coveted double climate dividend when executed correctly—destroying a potent greenhouse gas at the waste source while displacing fossil bunker fuel at sea. Yet neither “bio” nor “renewable” shields a fuel from rigorous lifecycle scrutiny: the actual carbon balance hinges on parasitic energy loads, fugitive methane leakage, and unvarnished well-to-wake greenhouse accounting. READ MORE