Challenge: Maximize production while controlling costs to meet market dynamics
The United States continues to see sustained demand for fuel ethanol as more cities and states have adopted policies encouraging or requiring the use of ethanol in gasoline. Dry grind ethanol production also produces distillers dried grains with solubles (DDGS) and wet distillers grains with solubles (WDGS), which are in demand as livestock feed.
Thus, it’s not surprising that what began as a committee of farmers and businesspeople interested in building a value-added ethanol production facility quickly resulted in a full-scale ethanol plant. The plant is capable of grinding 13 million bushels of corn, producing 35 million gallons of ethanol, and generating more than 170,000 tons of wet and distillers dried grain per year.
The rapidly growing markets for ethanol, DDGS and WDGS mean that manufacturers face great pressure to maximize production while controlling costs. Because even the smallest variables in the complex production process can impact yield, time to market, operating costs and profit margin, ethanol producers must constantly balance market dynamics with operational efficiencies.
Solution: Capacity Building with Rockwell Automation
Soon after it began operations, the forward-thinking team at the manufacturer began looking for ways to maximize production capacity and efficiency at its dry mill. Specifically, the team wanted to increase dryer capacity, decrease energy costs, increase DDGS moisture (and yield) and increase ethanol production through more stable beer column operation.
The team turned to Rockwell Automation, a recognized leader in predictive process control technology and environmental solutions for the ethanol industry, to implement FactoryTalk® Analytics™ PavilionX™ for process optimization.
The Rockwell Automation Solution enabled ethanol companies to drive operational performance to desired business objectives while maintaining regulatory compliance. Powerful capabilities for modeling, control, monitoring, analysis, visualization, warehousing and integration were combined to provide targeted solutions, delivering faster time-to-value and greater cumulative value than alternative solutions.
“The results we have achieved with Rockwell Automation have far exceeded our expectations…The Rockwell Automation Solution has given us the edge we need to boost our production capacity, with minimal additional investment in plant equipment.”
- Plant Manager, Ethanol Manufacturer
The ethanol manufacturer first worked with Rockwell Automation software engineers to clearly define requirements, clarify expectations and identify anticipated benefits. The project parameters included optimizing the plant’s evaporator, dryer and thermal oxidizer.
Rockwell Automation implemented its FactoryTalk Analytics PavilionX solution to optimize dryer performance by predicting and closed-loop control of moisture. The solution used a multivariable, non-linear controller that was used to generate and execute dynamic optimization and control. Its continuous process control was able to maximize the ethanol manufacturer’s dryer production 24 hours a day, seven days a week to yield the highest possible returns with the plant’s current equipment configuration.
The controller was designed to shift drying load from dryer to evaporator. It is also customized to reduce heat losses of the thermal oxidizer hotbox temperature, resulting in a decreased need for natural gas. It controls the thermal oxidizer’s process steam header pressure and the syrup evaporator (including syrup solids and steam consumption) in the beer column to manage and stabilize beer column separation with the residual evaporator steam. Rockwell Automation also customized the ethanol manufacturer’s solution to allow for higher average DDGS moisture, which increases DDGS yield.
Results: Increased production with reduced energy
As a result of implementing FactoryTalk Analytics PavilionX, the ethanol manufacturer increased production by 12%. The solution also allowed the plant to significantly reduce its energy usage, resulting in a 9.9% increase in energy efficiency.
Key Benefits
• 12% increase in ethanol production • 12% increase in throughput • 9.9% increase in energy efficiency • 3.3% reduction in standard deviation in dryer moisture
The ethanol manufacturer realized these significant benefits with minimal additional investment in plant equipment. The team estimates that the total value of the installation is more than $2.5 million per year based on industry average marginal values and cost of natural gas. The impressive project results demonstrate the significant amount of capacity hidden in production processes, readily available with the right process control solution.
