Benefits of Anaerobic Digestion Systems for Ethanol Producers Highlight Strengths of Closed-Loop Integration

Benefits of Anaerobic Digestion Systems for Ethanol Producers Highlight Strengths of Closed-Loop Integration

With advantages of minimizing operating costs and maximizing use of resources in the production process, AD systems offer practical supplements to ethanol producers.

Industries that produce large quantities of a given commodity often depend on optimization of process design to safeguard their profit margins, long-term viability, and market competitiveness. With many markets being susceptible to price fluctuations, the ability to guarantee cost savings as well as resource optimization not only provides advantages economically, but also environmentally.

Electricity, thermal energy, and water consumption are among the cost drivers of ethanol production. Along with these constants, a number of waste streams in ethanol facilities require cleanup— evaporator condensate streams, dryer/scrubber streams, and any number of other miscellaneous waste streams specific to a given facility must be treated. One of the best solutions to cover these costs most effectively is integrating a combination of Anaerobic Digesters, Combined Heat and Power (CHP) units, and wastewater treatment plants into the facility’s operations.

Anaerobic systems convert influent organics almost entirely into methane and CO2, generating very little excess sludge in the process. The high organic load in the waste streams of ethanol facilities makes this water particularly well-suited to an anaerobic process. What’s more, effluent from anaerobic treatment systems can often be recovered and returned to the ethanol production process, lessening the facility’s water demands.

Anaerobic systems can also provide a more reliable, cost-effective process for treating thin stillage (when used in reference to ethanol production, ‘stillage’ refers to the liquid, mostly water, left over after fermentation and distillation; stillage has some nutrients in it). In addition to generating energy, the solids extracted from the thin stillage treatment system’s effluent can be sold for use as an effective soil conditioner. Adding to this a collaboration with local-area farmers, and a beneficial synergy can be created that reduces waste even more, and treats it as a resource to maximize the Triple Bottom Line. Animals generate manure, and ethanol production generates thin stillage. The manure and stillage are fed into a comingled anaerobic digester, eliminating the need for either party to dispose of these waste streams by conventional methods. The digester produces biogas which generates enough electricity—depending on the configuration—to satisfy the ethanol facility’s needs. The ethanol facility, in turn, produces dry grain which is fed back to the cattle, which in turn generate more fuel for the digester. The system produces very little waste, and both the ethanol facility and the farm benefit.

With team members providing innovative Bio-Ethanol plants, Anaerobic Digesters, CHP units, and Wastewater Treatment plants, Team Gemini offers a complete solution set for ethanol producers and other commodity-intensive industries. Design and development are integral in establishing economic viability, as various cost factors, technology configurations and applications, and other details vary from project to project. Team Gemini is part of this process, and making sure that all requirements are met and implemented for clients to most effectively apply sustainability measures in their operations.

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