Developed by scientists at the Pacific Northwest National Laboratory (PNNL), the technique involves taking bioethanol from renewable feedstocks and converting it to n-butene using a microchannel reactor embedded with a patented catalyst. N-butene, which is currently derived from fossil fuels, can then be further processed into products such as diesel, jet fuel and industrial lubricants.
“Biomass is a challenging source of renewable energy because of its high cost,” said Vanessa Dagle, co-primary investigator of the initial research study, which was published in the journal ACS Catalysis. “Additionally, the scale of biomass drives the need for smaller, distributed processing plants. We have reduced the complexity and improved efficiency of the process, while simultaneously reducing capital costs. Once modular, scaled processing has been demonstrated, this approach offers a realistic option for localised, distributed energy production.”
PNNL partnered with Oregon State University (OSU) to integrate the novel chemical conversion process into microchannel reactors using 3D printing. This allowed the research team to create a pleated honeycomb of mini-reactors that significantly increased the effective surface-area-to-volume ratio available for the reaction.
“The ability to use new multi-material additive manufacturing technologies to combine the manufacturing of microchannels with high-surface-area catalyst supports in one process step, has the potential to significantly reduce the costs of these reactors,” said OSU lead researcher Brian Paul.
Currently, one of the major impediments to using biomass for fuel is the need to transport it long distances to large, centralised production plants, which significantly adds to the overall cost. According to the researchers, the new microchannel technology could allow commercial-scale bioreactors to be built near agricultural centres where the majority of biomass is produced.
“The modular design reduces the amount of time and risk necessary to deploy a reactor,” said Robert Dagle, co-primary investigator of the research. “Modules could be added over time as demand grows. We call this scale up by numbering up.”