Chromatographic Rectification of Ethanol

Abstract

A scalable technology for purifying ethanol from a dilute aqueous solution of ethanol, the technology incorporating vaporization of ethanol coupled with a chromatographic rectification process comprising feeding a vaporized ethanol / water mix onto a plurality of molecular sieve beds, to produce dehydrated ethanol vapor, which can then be condensed to recover purified dehydrated ethanol liquid. The scalable technology process is suitable for farm-scale production of fuel-grade ethanol, having the added benefit of allowing wet distillers grains to be used on-site as live-stock feed, thus eliminating the energy and shipping costs associated with drying and off-site distribution of the grains portions generated during the rectification process. Scalable technology, as provided herein, is also suitable for recovery of ethanol from processes which use ethanol during manufacture of a product. Current embodiments of the scalable technology as disclosed herein are suitable for production of fuel-grade ethanol at quantities of anywhere from about 1000 gallons per year to upwards of hundreds of millions of gallons per year, by reducing energy requirements and costs and reducing pollution, thereby minimizing the economy of scale effect to create a technology scalable to any output need. Embodiments disclose a plurality of smaller molecular sieve beds in series and use heat generated during desorption and regeneration of the molecular sieve beds as an energy source to aid in the vaporization step.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present application is a continuation of U.S. application Ser. No. 11 / 471,460 filed Jun. 20, 2006, issuing as U.S. Pat. No. 7,507,273 on Mar. 24, 2009, and which claims priority from U.S. Provisional Patent Application Ser. No. 60 / 692,152 filed Jun. 20, 2005, the entire contents of both of which are incorporated by reference herein.TECHNICAL FIELD AND BACKGROUND ART[0002]The present invention relates to rectification of ethanol and production of fuel grade ethanol from beer using an energy efficient chromatographic rectification process.[0003]The production of fuel grade ethanol by fermentation has become a large source of transportation fuel in the United States and in particular, in the corn belt states of Indiana, Illinois, Iowa, Minnesota and the Dakotas. Ethanol is produced typically from corn, but other substrates are available by the yeast fermentation of sugars to produce a beer containing typically from 10 to 15% ethanol. The...

AI Technical Summary

Benefits of technology

[0005]In a first embodiment of the invention there is provided a scalable technology for purifying ethanol from a dilute aqueous solution of ethanol, the technology incorporating vaporization of ethanol coupled with a chromatographic rectification process comprising feeding vaporized ethanol / water mix on a plurality of molecular sieve beds in series, to deliver dehydrated ethanol vapor, which can then be condensed to dehydrated ethanol liquid. The scalable technology process is suitable for farm-scale production of fuel-grade ethanol, having the added benefit of allowing wet distillers grains to be used on-site as live-stock feed, thus eliminating the energy and shipping costs associated with drying and off-site distribution of the grains portions generated during the rectification process. Eliminating the need for drying the grains portion also eliminates the pollution generated in the form of volatile organic compounds during the drying process. Scalable technology, as provided herein, is also suitable for recovery of ethanol from processes which use ethanol during manufacture of a product, such as, for example recovering ethanol from a gum production process where ethanol is added to precipitate the gum product. Current industrial-sized distillation systems, which produce upwards of one hundred million gallons of fuel-grade ethanol / per year and utilize vast amounts of energy, mostly unrecovered as heat loss, benefit from large economy of scale, making them unsuitable for smaller-scale production needs. In contrast, current embodiments of the scalable technology as disclosed herein are suitable for production of fuel-grade ethanol at quantities of anywhere from about 1000 gallons per year to upwards of hundreds of millions of gallons per year, by reducing energy requirements and costs and reducing pollution, thereby minimizing the economy of scale effect to create a technology scalable to any output need. The reduction in energy output, cost requirements and pollution, and minimization of the economy of scale effect is achieved by replacing standard distillation / molecular sieve bed technology with a chromatographic rectification system directly following vaporization, the chromatographic rectification system employing a plurality of smaller molecular sieve beds, either in series or parallel, and using heat generated during desorption and regeneration of the molecular sieve beds as an energy source to aid in the vaporization step.

Problems solved by technology

Current industrial-sized distillation systems, which produce upwards of one hundred million gallons of fuel-grade ethanol / per year and utilize vast amounts of energy, mostly unrecovered as heat loss, benefit from large economy of scale, making them unsuitable for smaller-scale production needs.

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