Research discovers enzyme that transforms distiller’s corn oil (DCO) into aviation biofuels

CNPEM study, which detailed the structure and functioning of the enzyme, was published in Nature Communications

A discovery by the Brazilian Center for Research in Energy and Materials (CNPEM), in Campinas (SP), points out ways to transform distiller’s corn oil into renewable fuels, such as biokerosene and green diesel. The study, published in Nature Communications, details the structure and functioning of a natural enzyme capable of generating hydrocarbons similar to those obtained in oil refineries.

The enzyme identified by CNPEM’s Brazilian Biorenewables National Laboratory (LNBR) has an important differentiator for DCO to take on a prominent role in the advanced fuel industry such as green diesel and biojet fuel: it is highly efficient and withstands high temperatures, which allows its direct application in this co-product of corn ethanol production — currently underutilized.

The enzyme is able to act in the DCO processing, an acidic raw material with a high content of free fatty acids. The enzyme performs the decarboxylation of DCO, removing oxygen from fatty acids, transforming them into molecules very similar to those obtained in the oil refining process. In addition to fuel, the resulting compounds can be used in the production of plastics, cosmetics and other industrial products.

Imagem ampliada do sítio catalítico da enzima, destacando a ligação do ácido oleico durante sua conversão em hidrocarboneto. O ácido oleico é um dos principais ácidos graxos presentes no DCO. Na estrutura, os átomos estão representados por cores: bolinhas vermelhas indicam átomos de oxigênio, azul-escuro representa nitrogênio, verde-azulado corresponde ao carbono e o átomo de ferro está em tom rosado (Divulgação/CNPEM)

In Brazil, in 2023, 145,700 tonnes of DCO were produced in the corn ethanol industries, which could be used for fuel production. Globally, DCO production is estimated at 4.3 million tonnes per year. CNPEM is a pioneer in studies on the use of this raw material for hydrocarbons sustainable production using enzymes. For industrial application, there are still stages to be overcome, but the discovery represents an important step towards the technology being licensed.

“The great challenge was to find an enzyme that could work directly with raw and varied materials, such as industrial by-products and/or co-products. We were able to not only identify this enzyme, but also completely elucidate its ways of action and understand which characteristics made it extremely efficient in acting on DCO”, explains researcher Letícia Zanphorlin, from CNPEM, who led the study. To get to this information, researchers turned the enzyme into crystals so that its atomic structure could be revealed by protein crystallography carried out at Sirius’ Manacá beamline.

Besides the scientific impact, the discovery has implications for sustainable development. In Brazil, corn ethanol is a growing industry, especially in the Midwest, where corn is planted between soybean crops, without the need for new agricultural areas. The oil generated in corn ethanol production, which currently has little commercial application, can now be converted into fuel for long-distance transportation, increasing the economic return of the production chain, and contributing to the sector’s circularity.

“In initiatives like this, CNPEM have been betting in solutions that value sustainability in a broader way, going beyond the reduction of greenhouse gas emissions, and including issues related to the responsible use of natural resources and maintaining the balance of our ecosystems”, highlights the director of LNBR/CNPEM, Eduardo Couto.

“Technology adds value to the maize chain and strengthens sustainability. This chain generates ethanol, DDGS (Distiller’s Dried Grains with Solubles) and DCO. DGGS already becomes animal feed, and now the residual oil can have a very important destination, which is SAF (sustainable aviation fuel), for example”, explains Letícia. She also points out other raw materials potential, such as babassu and macauba, that are on the radar for future studies.

Bridge to the industry

This project exemplifies how scientific innovation can boost the sustainability and competitiveness of Brazilian industry. Funded by Sinochen, now incorporated by PRIO — Brazil’s largest independent oil and gas company — and with support from Embrapii (Brazilian Company for Industrial Research and Innovation), the study received approximately R$10 million in investments aimed at Research, Development and Innovation.

“The corn ethanol industry is booming in Brazil, and this technology creates a unique opportunity to transform byproducts into high-value items”, adds Letícia Zanphorlin, from CNPEM. The next step is to expand the scale of the process, looking for new applications in the market.

About CNPEM

The Brazilian Center for Research in Energy and Materials (CNPEM) is home to a state-of-the-art, multi-user and multidisciplinary scientific environment and works on different fronts within the Brazilian National System for Science, Technology and Innovation. A social organization overseen by the Ministry of Science, Technology and Innovation (MCTI), CNPEM is driven by research that impacts the areas of health, energy, renewable materials, and sustainability. It is responsible for Sirius, the largest assembly of scientific equipment constructed in the country, and is currently constructing Project Orion, a laboratory complex for advanced pathogen research. Highly specialized science and engineering teams, sophisticated infrastructure open to the scientific community, strategic lines of investigation, innovative projects involving the productive sector, and training for researchers and students are the pillars of this institution that is unique in Brazil and able to serve as a bridge between knowledge and innovation. It is responsible for operating the Brazilian Synchrotron Light (LNLS), Biosciences (LNBio), Nanotechnology (LNNano), and Biorenewables (LNBR) National Laboratories, as well as the Ilum School of Science, which offers a bachelor’s degree program in science and technology with support from the Ministry of Education (MEC).