The digester consumes effluent from the beer-making process, among other wastes. Tour participants got to view the biomass used in the anaerobic digestion process through a microscope, almost making it possible to catch a glimpse of the tiny microbes that live on the granular biomass and carry out the process. The system takes in about 3 million gallons of wastewater per day and reduces the facilities’ organic waste by about 80 percent. Material screened out of the wastewater is sold to a family horse radish farm in southern Illinois. The digesters produce about 900,000 square feet of biogas per day, used to generate process heat for the company’s plant.
Randazzo explained that the microbes reproduce and grow quickly, making it necessary to get rid of some of the digester biomass after its depth in the tanks reaches around 30 feet. Twenty-five is ideal, he added.
Randazzo also took tour guests past the evaporation coolers, designed to keep temperatures in the process below 103 degrees Fahrenheit. The microbes can survive lower temperatures and the coldest conditions they’ve worked under is about 85 degrees F.
At the end of the Anheuser-Busch visit, BBI International, publisher of Biomass Power & Thermal, surprised its tour guests with a few cases of beer reserved for the end of the day.
The next stop was the IESI MO Champ Landfill and while BBI didn’t provide complementary bags of trash, the 254-acre site proved to be an exciting location. Because of constant truck traffic, tour guests saw the landfill through the bus windows. A landfill gas recovery operation at the site provides renewable electricity for two asphalt plants, a commercial greenhouse, a concrete facility and a local high school. Plans for expansion of the landfill gas utilization system are slated for operation in August 2012 and will be carried out by electric company Ameren Missouri. The expansion will increase electricity production to about 15 megawatts (MW) and to about 60 MW in 2025, the landfill’s tour guide said
The site also serves as a limestone mine and one of its two landfills sits at the bottom of a 250-foot deep mining trench. The bus crossed a one-way bridge before driving partway into the enormous hole for tour attendees to view a landfill only partially full. A large portion of the black ground liner remained exposed with massive trucks pushing around the garbage piles.
On the way off the site, the tour bus was required to take the same precautions as all other exiting traffic to minimize the amount of sediments and mud removed from the location. It entails driving through a strong sprinkler-type mechanism that essentially creates a white wall of recycled water.
Last, the group stopped at Innovative Energy Inc. to see its 2 MW model of its gasifier in the St. Louis suburb of Fenton. The system can gasify any carbon-based fuel, including wood, municipal solid waste, ag residue, energy crops, plastics, tires, shingles and paper. During the tour, though, the company was experimenting with some switchgrass pellets. CEO Glenn Foy explained that many biomass projects fall through because of feedstock issues. “We thought fuel flexibility was critical,” he said.
The site also has its own briquetting process and Foy displayed a jar full of biochar that he compared to tiny BBs. The gasifier itself is quite small, at about 4 feet in diameter and 15 feet tall. A yellow rope separated the tour guests from the gasifier’s processes, but several company employees spoke to the crowd about the system using diagrams and flow charts to illustrate its functions. Because it is a distributed energy system it doesn’t require transmission lines like wind, coal and hydropower to get the power from where it’s produced to where it will be used, they said.
Innovative Energy was founded in 2001 and has 27 worldwide patents, said Jim Neumeier, vice president of business development. The privately funded company completed its research and development phase at the end of 2009 and since 2010 has been marketing its technology, concentrating on five sectors: municipalities, military, international, commercial and industrial facilities that have waste streams.
Driving back to the city, tour guests discussed the compelling aspects of all the projects and wondered about the proprietary elements of Innovative Energy’s system and what might set it apart from other gasifiers. The company is also an exhibitor at the International Biomass Conference & Expo. For information on the event, click here.