How Taxonomies Lead to Fuel Pathway - The Bio/Synthetic Pathway

THE BIO/SYNTHETIC PATHWAY

This category includes fuels that are produced from biomass, including plants, waste oils and agricultural waste. Catalytic processing and upgrading of biomass can yield liquid fuels with physical and chemical properties comparable to diesel oil; this is desirable from a design standpoint because they can be used as drop-in biofuels with minimal or no changes to marine engines and their fuel delivery systems.

Bio-/Renewable Diesel → Gas-to-Liquid Fuels → 2nd and 3 rd generation biodiesel

Currently, the most widely used component is fatty acid methyl esters (FAME) or biodiesel, which is described in the latest ISO (8217/2017) specifications for marine fuel blends and is being offered by major oil companies.

The standard allows for seven percent biodiesel in the fuel blend, but some shipowners are testing richer blends, from 20 to 100 percent. FAME is a first generation biofuel and faces challenges associated with its poor oxidative stability, and its potential to degrade over time.

Hydro-treated vegetable oil (HVO) is a second generation biofuel, which is not produced from food crops. It is often referred to as renewable diesel and produced using modern hydro-treating processes, which yield high-quality fuels with better stability than FAME biodiesel.

HVO has similar physical and chemical properties to marine gas oil (MGO), making it fully compatible with existing engines and fuel-delivery systems. Renewable diesel also can be produced from biomass gasification, using the Fischer-Tropsch (FT) process. It is often referred to as a gas-to-liquid or biomass-to-liquid fuel.

Renewable diesel fuel is thought to be a promising medium- to long-term solution for shipowners, because it can offer a significant reduction in carbon output with minimal capital expenditures.

Electro-fuels: Using renewable energy to produce electro-fuels from biomass could reduce the energy required for their production, and thus reduce their life-cycle carbon footprint. This technique can be applied to any of the three fuel pathways to produce bio-LNG, bio-methanol or renewable diesel.

Electro-fuels have the potential to offer carbon-neutral propulsion and can provide solutions in the medium- to long-term. In addition to fossil and biomass sources, electro-fuels can be produced by carbon dioxide recovery (CDR), a technique that converts CO 2 to syngas, which in turn can be used to produce bio-LNG or bio-methanol.

CDR has the potential to remove CO 2 from the atmosphere and use it for production of electro-fuels, thereby minimizing the energy needed for fuel production and their potential to reduce global warming.