1A-06

Large Scale Ethanol Fermentation through Pipeline Delivery of Corn Stover

Amit Kumar, Jay B. Cameron and Peter C. Flynn^*

4 – 9 Mechanical Engineering Building

Department of Mechanical Engineering

University of Alberta

Edmonton, Alberta, Canada T6G 2G8

Phone:   (780)492-6438

Fax:  (780)492-2200

E mail: peter.flynn@ualberta.ca

Corn stover is available in abundance in the central U.S.; total annual supply exceeds 150 M dry tonnes per year.  Truck congestion is a major factor in the size of any corn stover receiving facility; a facility processing 2 M dry tonnes per year requires a truck to arrive every 4 to 8 minutes.  Community resistance would likely preclude receiving facilities of larger capacity.  Ethanol fermentation plants processing corn stover are below economic optimum size at this capacity.

Multiple pipelines transporting corn stover to an ethanol fermentation facility offer the potential to achieve a significantly more economic scale for production and distribution of ethanol. 

This study compares the cost of produced ethanol from a large number of small ethanol plants, processing 0.7 M dry tonnes of corn stover per year, to a large facility processing corn stover delivered by multiple pipelines each having a capacity of 2 M dry tonnes per year.  Data for the small facilities is drawn from previous detailed studies by the National Renewable Energy Laboratory, and is compared to a larger plant processing 4 to 24 M dry tonnes per year.

Saccharification of corn stover can occur in the pipeline during transport.  The cost of ethanol production from a large central processing facility is evaluated with and without simultaneous saccharification.  Since saccharification occurs at elevated temperatures, one key cost factor in simultaneous saccharification is the availability of waste heat at the pipeline inlet.