Dennis Day’s Ethanol Plant

Dennis Day's Ethanol Plant
Out in the Northwest corner of the Des Moines Area, along the border of Grimes and Urbandale sits what remains of Dennis Day’s ethanol plant. This was not the first ethanol plant in Iowa, but it is significant to the entire ethanol industry because this is where Dennis Day introduced the molecular sieve to the ethanol indusrty.

The idea for for using ethanol for motor fuel is not new. Though for much of the history of ethanol production for use as motor fuel, the key challenge was to reduce the water content to a point where it was suitable for motor fuel. Simple distillation only achieves between 175 and 185 proof ethanol. To be suitable for motor fuel, the ethanol must be anhydrous. The previous methods for producing anhydrous ethanol involved compound distallation and the introduction of highly toxic benzene into the process. This process was expensive, dangerous and prone to operational failures.
Base of the distillation column
The molecular sieve had already been in use in the petroleum industry for many years and it was at the natural gas plant in Redfield where Dennis’ son Wayne observed it in use. Wayne discussed the possibility of using a molecular sieve to produce anhydrous ethanol with his father, who was already interested in ethanol as a value-added farm product.

Shortly thereafter, Dennis contacted his friend Larry Hunt of Hunt Sprayers Inc. in Hartford about building a molecular sieve to produce ethanol on the farm.

Dennis Day with his sons Dale(L) and Russ(R)

Larry already had the manufacturing capability needed to build a molecular sieve and also provided financial backing to the project. The actual construction of the molecular sieve was not that difficult, but a new challenge arose when it came to providing automated control to operation of the molecular sieve. Dennis’ son Russ who was an avid computer hobbyist, suggested computer control and took on the task of developing the software needed to control a molecular sieve.

The molecular sieve proved to be a complete success and was widely adopted across the ethanol industry. Dennis’ ethanol plant was frequently visited bus loads of people interested in seeing Dennis’ on-farm ethanol plant. Astronaut Gordon Cooper once landed his ethanol-powered airplane at the farm.
Dennis Day with Jane Fonda
One day, Dennis learned that he was going to be visited by Jane Fonda. Dennis didn’t particularly care for Jane Fonda. Dennis thought that day was a good day to work on truck tires. He got his hands as dirty as he possibly could for the moment when he could offer to shake hands with Jane Fonda.

By the mid-1980’s, changes in the ethanol industry caused Dennis’ ethanol plant to fall silent. Dennis passed away in 1995. The plant had sat dormant for over a decade and with a heavy heart, Dennis’ family dismantled the ethanol plant except for the distallation column, which stands to this day.