(205c) Ozone-Cracking of Lipids to Synthesize Biokerosene and Its Combustion Performance in Diesel Engines

Net-zero emission is the globally admitted strategy to mitigate climate change. The United States will achieve carbon neutrality by 2050 by replacing the fossil economy with a bioeconomy through bio-based fuels, chemicals and materials. The transportation sector is a major GHG contributorin the United States. With passenger vehicles and small trucks with internal combustion engines being phased out by electric vehicles by 2035, heavy-duty engines, such as airplanes, still use liquid fuels for the foreseeable future. Various approaches have been investigated for biofuel synthesis from renewable sources to reduce GHG emissions. However, these technologies own several disadvantages, such as high energy consumption in production and refinery, low yields of target products, or harsh reaction conditions.

Herein, energy-efficient technology is desired to achieve net-zero or even negative carbon emissions. Lipids produced from crops, algae, or lignocellulosic sugar fermentation can be promising feedstocks for synthesizing low-carbon footprint fuel. Because of the high content of carbon-carbon double bonds, the current cracking refinery technologies can result in a high content of undesired aromatic molecules, resulting in undesired emissions, such as smoke, soot etc. Energy-efficient ozone cracking works as an alternative to the current thermal-based cracking process for low carbon footprint fuel production from lipids. Part of the ozonized products, carboxylic acids, reacted with bio-based alcohols to synthesize esters called biokerosene. Our results show that these products could be excellent alternatives to jet fuels or kerosene because of the excellent cold flow properties with cloud points as low as -70 ^oC. Alcohol types significantly influence viscosities and combustion heat. In addition, the products exhibit outstanding oxidation stability and thermal stability. The combustion performance of biokerosene and biokerosene-jet fuel blends in diesel engines was measured. The existence of oxygen facilitates combustion, resulting in low emissions of hydrocarbons and carbon monoxide and high carbon dioxide emissions. Moreover, biokerosene can reduce nitrogen oxides emissions. Therefore, our proposed approach provides an energy-efficient way to produce alternatives to petroleum-based jet, kerosene, and diesel fuels.