University of Nebraska–Lincoln researchers studying how to reduce ethanol’s water and energy footprint

In Nebraska, Nebraska researchers are studying how to make ethanol production more environmentally sensitive by reducing the amount of water and energy required to produce it and cutting the air emissions that result.

The Nebraska Environmental Trust is helping fund this University of Nebraska–Lincoln research — $155,663 this year and $44,232 in a second year.

Ethanol fermentation generates gaseous emissions including carbon dioxide and hazardous air pollutants such as acetaldehyde, formaldehyde and acrolein, among other compounds. Each ethanol plant has a federally enforceable limit of HAPs to be emitted annually.

Decreasing HAPs in ethanol plants requires web scrubbers, which remove excess ethanol and HAPs from the fermenter off-gasses, and thermal oxidizers, which combust off-gasses generated from drying wet distillers grain.

Excess water and energy are needed to operate the scrubbers, with the water typically recycled into the liquefaction process. Part of the excess water evaporates during wet distillers grain drying, and the rest ultimately leaves the plant in distillers grains.

Grant funds will be used to buy sampling equipment to monitor these air emissions at Nebraska ethanol plants. Gas samples will be tested at a UNL lab.