Aemetis Debuts First Mitsubishi ZEBREX Ethanol Dehydration System In North America

Aemetis Commissions US$10 Million Mitsubishi ZEBREX System At Keyes Plant, Reducing Petroleum Natural Gas Use By 20% And Lowering Ethanol Carbon Intensity

Aemetis Inc. (Aemetis) a renewable natural gas (RNG) and renewable fuels company focused on negative carbon intensity products, completed the installation and commissioning at the Keyes ethanol plant in California. It is the first Mitsubishi system in North America, reducing overall energy use and lowering the carbon intensity of ethanol. The system is now fully operational, reducing energy costs and increasing biofuel value by more than US$5 million per year. The cost of equipment, engineering, and installation of the Mitsubishi ZEBREX system was approximately US$10 million. Aemetis expects to receive more than US$1 million of grant funding from the PG&E and CPUC Energy Efficiency Program in support of the project.

The Mitsubishi Chemical Corporation ZEBREX ethanol dehydration system was commissioned after several years of engineering design, fabrication, installation, and testing at the Aemetis 65 million-gallon-per-year, low-carbon ethanol plant. The patented ZEBREX technology replaces the energy-intensive molecular sieve ethanol dehydration process used by most fuel ethanol plants in the world. The Aemetis plant upgrade is the largest implementation of the ZEBREX system worldwide.

The upgrade from the traditional pressure swing adsorption (PSA) ethanol dehydration process to the ZEBREX system has reduced petroleum natural gas consumption at the Keyes facility by more than 20%, which is estimated to provide energy savings of approximately US$3.4 million per year. By reducing the amount of fossil fuel energy used in the production process, Aemetis expects to receive a lower carbon intensity score for the fuel ethanol produced at the Keyes plant, which will increase revenue for each gallon of fuel ethanol sold. “Implementation of the Mitsubishi ZEBREX technology at the Aemetis Keyes plant completes another significant project as we transition our ethanol production process from petroleum-based energy sources to renewable electricity,” said Andy Foster, president of Aemetis Advanced Fuels Keyes Inc. “Our engineering team worked closely with Mitsubishi in Japan to customize the design of the system for large-scale fuel ethanol production. The ZEBREX technology is delivering as promised and Mitsubishi has been an outstanding partner throughout this multi-year process.”

The Aemetis carbon intensity reduction projects at the Keyes ethanol plant include a 1.9-MW solar microgrid with battery backup that will produce zero-carbon electricity to reduce natural gas usage and a mechanical vapor recompression system that uses electric motors. Combined, the Aemetis carbon reduction projects are expected to reduce the use of petroleum natural gas at the Keyes biofuel facility by 85%, which will save the company more than US$1 million per month in natural gas costs and provide a significant increase in the value of the ethanol produced at the plant.