The Competitive Edge: Drystill Holdings Inc.

by Helena Tavares Kennedy (Biofuels Digest) ... Drystill invented a low temperature low energy distillation technique. While beneficial in a many industrial sectors, it has can be particularly helpful in reducing capital and operating costs in the biofuel industry. The technology can be used worldwide for both first and second generation biofuels. It may be applied from initial plant design or added as a bolt-on enhancement to an existing plant.

Conventional distillation is a hot operation which causes thermal fouling of heat exchange surfaces, denatures enzymes, kills biocatalysts, and demands extra heat to bring fermentation broth to its boiling point. Drystill’s room temperature process avoids these problems.

Besides enabling enzyme and yeast recycling, low temperature ethanol removal makes possible an advanced money-saving concept in fermentation whereby ethanol is removed from the broth as it is produced.

Drystill is a technology provider ready to assist biofuel producers (or companies intending to become biofuel producers) to enhance the economic returns of their plants through the use of new advanced separation technology. Drystill can also license its technology to companies with sophisticated internal engineering capabilities that wish to incorporate it into their own proprietary processes.

Drystill technology shrinks utility, fermentation, and separation equipment leading to smaller overall footprint and capital investment in a small-plant setting. Those who see the advantage of a farm-scale or community scale ethanol plant will want to evaluate Drystill’s approach.

The key block in a bio-refinery’s block diagram is labelled “Fermentation”. Upstream are important blocks that have been the focus of brilliant efforts by many innovative firms. However the single downstream block labelled “Ethanol Removal” is always filled by the same equipment. It is technology inherited from the petrochemical industry and it embodies very little innovation specific to the bio-industry. Such lack of progressiveness is on one hand surprising as this block accounts for most of the utilities consumed in the entire plant.

Drystill offers the only practical technology that can remove ethanol from a living fermentation broth and leave both yeast and enzymes unharmed.

Ethanol is toxic to the microorganisms that produce it. As the concentration of ethanol increases in the broth, the microorganisms become less and less productive. This phenomenon is called “product inhibition”. It greatly extends the length of time necessary for the sugar in the broth to be converted to ethanol.