Case Study: Stainless Steel RTOs for Ethanol Emissions and Odors

Industry

Ethanol Processing

Problem

A 42 million gallon expansion at an ethanol production plant in Nebraska was certain to put the dry mill out of emission compliance for Hazardous Air Pollutants (HAPs), Volatile Organic Compounds (VOCs), carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM), all regulated by the EPA. Ethanol production facilities in the United States are permitted to operate under a ‘minor source’ status as long as the total tonnage of key pollutants are below the 100 tons per year limit but operating restrictions, penalties and fines, as well as community pressures are forcing many plants to strive for the lowest possible emission levels, enabling future capacity expansions.

Action

Anguil Environmental Systems Inc. has been awarded a multi-million dollar contract to assist the ethanol plant in meeting Environmental Protection Agency (EPA) regulatory requirements.

Solution

Anguil, a leading emission control equipment provider was chosen after demonstrating their ability to provide a cost-effective, reliable solution for the Nebraska ethanol plant.  Known for their low operating cost and high destruction rate efficiency, the Anguil Regenerative Thermal Oxidizer (RTO) was selected as the best available control technology for the application.  The pollution control device will consist of two side-by-side Anguil RTOs handling a process volumetric flow of 120,000 SCFM (Standard Cubic Feet per Minute).  The system will achieve greater than 99% destruction rate efficiency for air pollutants and odorous emissions with 95% thermal energy recovery, insuring low fuel usage.  Portions of the equipment will be constructed of 304-stainless steel to protect against corrosion from the ethanol process stream.  The project scope consists of equipment design, manufacturing, installation supervision, process integration and start-up.

While several options and suppliers were considered, Anguil was awarded the contract after the Nebraska producer evaluated system reliability, capital costs, destruction rate efficiency and operating cost estimates.  Production has begun on the oxidizer system and the project is slated to be up and running by April of 2007.