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What is needed to significantly increase production of bio-LPG, renewable marine diesel, and bio-aromatic hydrocarbons like BTX?

Oct-2024

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Andrew Layton, KBC (A Yokogawa Company), andrew.layton@kbc.global

- Sources: Most bio-LPG and biodiesel biofuels now come from recycled fats and vegetable oils, which do not compete with food sources. Recycled fats are the cheapest and most accessible source, but they still require pretreatment to remove several impurities. This pretreatment results in a 10% yield loss as water and requires additional isomerisation for diesel production. These factors increase the cost compared to conventional fuels, adding perhaps two extra steps.

The use of other waste or cheaper streams, such as woody feed sources, introduces additional issues with transportation costs, even more treatment, and potentially pyrolysis/gasification/Fischer-Tropsch steps before reaching conventional fuel-type treatment. Thus, the cost of these extra three to four steps in transportation and chemical treatment means the overall cost is several times higher than that of conventional fuels.

Production from electrolysis, H₂, and then reforming/F-T type processes to get to hydrocarbons is equally costly, especially if it starts from CO₂. CO₂ capture is feasible, but making hydrocarbons starting from CO₂ is like climbing a steep energy ladder, which was so easily descended by hydrocarbons going to CO₂.

- Scale-up: Apart from the bio-hydroprocessing route, most processes are still small and from smaller suppliers, requiring scale-up as well as managing solids – similar to recycling issues from multiple and contaminated sources. Several of these are best if they get together to provide a viable intermediate product. Existing refineries are designed to best manage or blend these products; thus, intermediate products need to be transported or built on-site if space permits.

- Investment: These processes require substantial investment. Money is available from bankers. However, due diligence is required for investors to assess the many small process start-up companies and identify those with viable business plans. Such due diligence often leads to turnarounds in the process configuration as various profit /practicality problems arise that were not predicted. Examples include basic changes in the source of H₂.

A solid business plan is essential to secure investment, as the cost of the final product is high, even with government support, and a firm customer base is vital. Some customers have already moved away from renewables in the short term. Additionally, some government support is disappearing or being delayed due to other economic drivers.

Many obstacles exist to quickly replace the conventional fuel supply routes, especially as the cost is high now. A key factor is choosing companies with good business and technology plans from cradle to product. In many cases, a robust plan may mean facilitating joint programmes between multiple companies.

Oct-2024