Simulating Complex Processes for Alternative Energy Production

Feb. 9, 2012
Complexity is a challenge when it comes to tapping into alternative energy sources, especially for those processes that gasify biomasses as fuel.

“These alternative energy processes, in a way, become combined chemical and power plants, which introduces a lot of unique operational and control issues,” says Steve Zitney, Ph.D., director of the Advanced Virtual Energy Simulation Training and Research Center at the Dept. of Energy’s National Energy Technology Laboratory in Morgantown, W.V. “So, you need software tools that cover both the chemical-process space and the power-generation space.”

To make working with these complexities more manageable, Zitney’s group is developing high-fidelity simulators using the Dynsim dynamic process simulation software and InTouch human-machine interface from Invensys Operations Management in Plano, Texas. One project resulted in an integrated gasification combined cycle (IGCC) simulator that also models the capture of carbon dioxide from the effluent streams from the gasification of just about any fuel, including pulverized coal and various biomasses. “It’s really combining a process dynamic simulator (for the gasification with a CO2 capture) with a more conventional combined-cycle power simulator,” he says.

“The DOE target for IGCC is 90 percent CO2 capture,” Zitney continues. Simulations show that the technology can hit this target under normal operating conditions. The hope is that the software will help researchers to develop advanced process control strategies for optimizing the capture under a wide variety of transient conditions and disturbances.

Because releasing carbon dioxide from the extraction solvent requires heat that could have otherwise generated electricity, the capture process has the effect of derating the plant.  Consequently, utilities will want control software for managing the capture, ramping it down at peak periods, ramping it back up when demand is lower, and removing obstacles for following the loads quickly.

The IGCC dynamic simulator is also finding uses in education and training. West Virginia University in Morgantown, for example, is already using it in a senior process control course. Utilities can also use it to train their control room operators and give them some experience virtually before coming online. They can go through an entire IGCC plant startup and shutdown, including an emergency shutdown, and learn to deal with disturbances.

NETL is also developing what it calls an immersive training system that adapts animation technology for creating three-dimensional virtual models of the plant. “It will be a full plant walk-through type model that will be directly connected to the real-time dynamic simulator, so we can do joint control room and field operator training,” says Zitney. “For example, a field operator will be able to use a controller like in a video game to walk up to a manual valve and close it in the virtual world. Engineers in the control room will be able see the impact of that change.”

Click here to read Automation World's feature on developments in automation for alternative energy sources.