GreenField Ethanol demonstrates membrane technology, may save 40% energy costs

GreenField Ethanol, Canada’s largest ethanol producer, announced it has completed a successful trial demonstration of new technology that will dramatically improve the ethanol production process.

At a project at its plant in Tiverton, Ontario, GreenField joined with Quebec-based Vaperma to demonstrate and study their membrane technology. The Vaperma Siftek membrane can remove more than 40 per cent water from an alcohol water mixture producing a 99 per cent fuel-grade ethanol product. Vaperma's process is unique to the industry and has the potential to revolutionize the alcohol production process.

GreenField Ethanol began discussions with Vaperma two years ago about installing a demonstration project at its Tiverton, Ontario ethanol plant. This project proved to be the first large-scale demonstration in North America of membrane technology for the dewatering of ethanol.

The Vaperma Siftek membrane is a high-performance, highly stable polymer membrane. The proprietary technology uses a polyimide-based material forming a solvent-resistant, asymmetric, integrally-skinned permeation membrane (schematic, click to enlarge).

To separate water from ethanol, water vapor permeates across the membrane at a much greater flux than ethanol. The high permeability of water is due to its relatively high adsorption and high diffusion rate in the membrane. The higher selectivity and permeance of water compared to ethanol are attributed to the unique polymer formulation and the membrane fabrication process.

Over the last 20 years, the Pressure Swing Adsorption (PSA) process using molecular sieve dehydration (MSD) has earned industry-wide acceptance in the separation of ethanol from water. This semi-continuous process produces a purge stream which contains between 60% and 80% ethanol that must be reboiled in the distillation process.

The Vaperma process allows for significant energy savings because the membrane eliminates distillation and molecular sieve units. By replacing these, GreenField would be able to save up to 40 per cent in energy costs:
energy :: sustainability :: biofuels :: ethanol :: distillation :: dehydration :: pressure swing adsorption :: membrane ::

The unit in Tiverton used substantially less energy and therefore fewer greenhouse gases were created in the process – reducing the plant's CO2 footprint. While our plants are all extremely efficient, the less natural gas we use to make steam, the better for the environment. - Robert Gallant, GreenField President and CEO

GreenField Ethanol, formerly Commercial Alcohols, is Canada’s leading ethanol producer. The company produces 250 million litres a year of corn-based fuel ethanol at its plants in Chatham and Tiverton, Ontario and Varennes, Quebec. Two more plants are under construction in Hensall and Johnstown, Ontario, and will be operational in 2008. GreenField Ethanol will be one of the top producers in North America with five operating plants, producing more than 700 million litres of ethanol per year by 2008. GreenField's Ethanol is available at more than 1,500 gas stations across Canada.

Vaperma is an emerging developer, manufacturer and supplier of advanced
gas separation systems. Vaperma breakthrough patented polymer membrane technology combines solvent and high temperature resistances into a strong hollow fibre which enables it to address new industrial applications. Yesterday, it officially opened its new 22,000 square-foot research and technology centre for the development and pilot testing of clean energy gas separation membranes.

Vaperma’s innovative hollow fiber membrane is a proprietary, made-in-Canada technology that represents a new “dewatering” process for the production of fuel ethanol. The technology also has strong potential for the dehydration of natural gas.