New Biochar Catalyst Achieves 96% Aromatic Yield from Microalgae for Sustainable Biofuel Production

Shenyang Agricultural University researchers develop a biochar-zeolite catalyst to turn microalgae into clean, high-value aromatic fuels with 96% selectivity.

By: AXL Media

Published: Apr 18, 2026, 10:58 AM EDT

Source: Information for this report was sourced from EurekAlert!

Engineering a Cleaner Path for Algal Biofuels

Microalgae have long been hailed as a cornerstone of renewable energy due to their rapid growth and ability to capture carbon dioxide without competing for food-grade land. However, the resulting bio-oil is historically plagued by high concentrations of oxygen and nitrogen, which diminish energy density and cause engine-clogging instability. To solve this, a team of scientists has engineered a composite catalyst that refines the conversion process. By integrating a biochar base with a zeolite coating, the researchers have created a system that selectively produces high-value fuels while stripping away the molecular impurities that previously hindered large-scale adoption.

The Strategic Pretreatment of Wet Torrefaction

Before the microalgae undergo chemical conversion, they are subjected to a specific pretreatment known as wet torrefaction. This preliminary step is designed to partially deoxygenate and denitrogenate the biomass, conditioning the feedstock for a more efficient breakdown. Following this, the material undergoes catalytic pyrolysis, where high temperatures decompose the biomass into smaller, volatile molecules. This dual-stage approach ensures that the raw biological material is physically and chemically prepared to interact with the catalyst, maximizing the recovery of usable energy from the original algae cells.

Achieving Precision in Hydrocarbon Selectivity

The newly developed HZSM-5 coated biochar catalyst has demonstrated an unprecedented level of precision in its chemical output. Under optimized experimental conditions, the process achieved a 96 percent selectivity toward aromatic hydrocarbons, such as benzene, toluene, and xylene. These compounds are critical building blocks for high-performance fuels and industrial chemicals. Under non-catalytic conditions, bio-oil typically contains over 80 percent oxygen and nitrogen compounds, but this new hybrid catalyst successfully reduced those contaminants to a negligible few percent, significantly enhancing the purity of the final fuel product.