Final Report: Enhanced Drying of Pipeline Ethanol

EPA Contract Number: EPD12021
Title: Enhanced Drying of Pipeline Ethanol
Investigators: Campos, Daniel
Small Business: Compact Membrane Systems Inc.
EPA Contact: Manager, SBIR Program
Phase: I
Project Period: March 1, 2012 through August 31, 2012
Project Amount: $80,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2012) RFA Text |  Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Sustainabile Utilization of Biomass


The need for low-cost production and shipment of fuel-grade ethanol from agricultural sources is continuing. Ethanol from agricultural sources has many advantages, including developing fuel independence and significantly reducing greenhouse gases. Bio-ethanol has significant value as an oxygenate and octane improver; however, the cost of ethanol still tends to be significantly higher than gasoline. President Bush spoke of his “Twenty in Ten” initiative in his 2007 State of the Union address. His goal was to reduce gasoline usage by 20 percent in the next 10 years and to require 35 billion gallons of renewable and alternative fuels in 2017. This alternative fuel will replace 15 percent of projected gasoline use. Although ethanol has many strong points, its high production and distribution cost most likely will limit its transition into the fuel industry.
Shipping by truck, ship or rail is a major contributor to the high cost of implementing fuel grade ethanol. Shipping ethanol by pipeline is significantly less expensive, but because ethanol is hydroscopic, pipeline ethanol usually includes water. This water can cause problems in engines and cause gasoline to irreversibly phase separate in gasoline-ethanol-water systems.
Compact Membrane Systems proposes a novel, simple and low-cost membrane process that can easily remove water from ethanol so that ethanol can be shipped by pipeline, and consequently, be less expensive than shipping by truck, ship or rail. In Phase I, Compact Membrane Systems fabricated a novel membrane system and then designed and fabricated laboratory membrane module systems consistent with the needs of in-line simple drying of pipeline ethanol.
The broad technical objective is to demonstrate a simple pervaporation system that can remove sufficient levels of water from pipeline fuel-grade ethanol to re-establish the target fuel-grade ethanol levels of less than 5,000 ppm of water in an economical manner. This needs to be done in a simple cost-effective system. The specific target is to do this for a cost that is 50 percent of the cost of shipping fuel-grade ethanol by truck or rail. This will provide significant driving force for the introduction of pipeline ethanol.

Summary/Accomplishments (Outputs/Outcomes):

  • A novel polymer was developed and customized for making membranes that are suitable for polishing fuel-grade ethanol that is contaminated with water after pipeline transport.
  • A process for coating a thin film of the novel polymer on a chemically and thermally resistant microporous support to produce the membrane for ethanol drying has been demonstrated.
  • The manufacture of the novel polymer was scaled up successfully, as well as the manufacture of developmental quantities of membrane.
  • The membrane coating process was optimized to produce optimum thickness, resulting in optimum water permeance of 1,500 GPU while maintaining maximum water/ethanol selectivity of 50.
  • Prototype membrane modules were successfully fabricated.
  • Pervaporation tests of the prototype membrane modules with mixtures of ethanol-water showed excellent water permeance and selectivity.
  • An extended test showed stable performance of the prototype membrane module, demonstrating the chemical and thermal stability of the membrane, support and sealing materials.
  • Economic and engineering analyses showed that the proposed product concept produces fuel-grade ethanol at an incremental cost of $0.005 to $0.014/gal when shipped via pipeline. This is significantly better than the stated goal of maintaining the drying cost at less than $0.075 per gallon.


Based on the Phase I results, the incremental cost of membrane drying added to the pipeline shipping cost is such that it would still be significantly cheaper than the cost of shipping by rail car. The membrane specifications to meet this need were demonstrated in the Phase I program and in conjunction with the economic analysis demonstrate feasibility of the proposed product.
In addition to achieving the program objectives, this membrane technology is synergistic with an EPA program need to dehydrate solvents for recycle. The same system under development in this program can be used for drying a variety of solvents used in the pharmaceutical industry (e.g., THF, IPA, acetone, etc.).
Phase I commercialization activities were targeted at developing interest from other parties with an ethanol plant willing to accommodate a field test of the Phase II prototype system. Working with Foresight Science & Technology during the Phase I project, Compact Membrane Systems has identified companies with expressed interest. In addition, a significant effort was expended to identify and understand the market, competition and needs of the ethanol community, not only pertaining to pipeline, but dewatering in general. This information is critical to the development of a viable plan to commercialize the membrane technology


Supplemental Keywords:

PFOA, water removal, ethanol, amorphous perfluoromembranes, perfluoro-octanoic acid, ethanol pipeline, SBIR