Cryogenic Processing
In 2008, Freez-it-Cleen created a buzz with a unique cleaning process that is saving the ethanol industry millions of dollars through improved efficiency and longevity on thermal oxidizers, a key piece of equipment in the ethanol production process. The cleaning process, which is called Cryogenic Processing, is simply put, sand blasting with a media that is not wet and does not leave behind potentially fouling residues.
Freez-it-Cleen is a dry ice blasting company that was founded in 2004. In late 2007, Freez-it-Cleen’s president Kelly Brannick approached an ethanol plant in Atwater, Minn., and asked if they were interested in having the company clean their grain receiving building. Instead, Freez-it-Cleen was tasked with cleaning the tubes on the boiler in the thermal oxidizer. Between the fall of 2007 and the spring of 2008, Brannick designed a unique tool that allowed the ability to clean every tube throughout the boiler.
The first job took the company almost 24 hours to complete and though it was a success, several difficulties were encountered. The specially designed tool worked, but did not hold up to the abuse, and using CO2 in a confined space had potential hazards that needed to be managed. Once the process was improved with newly designed, robust tools, Freez-it-Cleen was able to clean an entire thermal oxidizer safely in half the time.
It is the nature of the beast that boiler tubes and stack coils become fouled. Their design lends themselves to this and keeping them clean is paramount in reliability, longevity and efficiency. Through a study done by the Minnesota Technical Assistance Program, it was determined that cleaning with Freez-it-Cleen’s process a minimum of twice a year would improve a thermal oxidizer’s reliability, longevity and efficiency. The thermal oxidizer is typically cleaned during annual outages in the spring and the fall, so scheduling additional down time is not a requirement.
Centrifuge bowls & oil separators
Centrifuge bowls and Westfalia oil separators are also important pieces of equipment that the polishing effects of cleaning with dry ice can prove to be beneficial. Balance is a huge issue, and the fact that dry ice blasting does not etch or scratch the material and does not leave behind a residues that can be detrimental to operation, makes this cleaning process stand out from the rest. In 2009, Freez-it-Cleen further developed their process by designing and building fixtures that allow the company to clean an entire set of Wesfalia disks and associated pieces of equipment in less than 9 hours.
Grain receiving & load-out buildings
Other very important areas of concern are grain receiving and load-out buildings. These buildings become very dirty with a combination of road and corn dust. This will often trap moisture that is always present and oftentimes will perpetuate into mold and mildew creating an unhealthy environment for the operators, not to mention an explosion risk. Though dry ice kills mold, it will not eliminate the mold completely, which will always be part of doing business in the Midwest. In the summer time especially this can become a constant issue.
Cleaning grain receiving and load-out buildings does not require the plant be shut down. The cleaning can take place on weekends or at night when there is little or no traffic. This is often a process that does not need to be repeated annually, but every 2-3 years as build-up increases.
Looking forward
Freez-it-Cleen knows that as the ethanol industry comes under fire and scrutiny from people, including legislators, it will become extremely important to show that the companies within the industry are always working towards a better, cleaner and more efficient means of producing ethanol. The company’s proprietary and patent pending process can save the ethanol industry thousands of dollars. Freez-it-Cleen has created an easy to use spreadsheet that can be used to determine the return on investment (ROI). The spreadsheet demonstrates how cleaning makes the boiler more efficient and saves natural gas.
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