Improving power generation from fluctuating off-gas productions

Engineering plants typically have a variety of interlinked production chains, where process flows are dependent on upstream events and operated by default or manual settings. Burnable off-gasses are mostly utilized as energy sources. Raw material feeds may fluctuate over time, resulting in fluctuating off-gas production and potentially in inefficient energy resource usage. It is common practice to generate steam from off-gas, in boiler houses, where excess steam is allocated for power generation. Over time these fluctuating off-gas and therefore steam production may lead to turbine trips. Another problem is that unused off-gasses are burned to atmosphere, where the energy potential is nullified. This paper investigates the more efficient utilization of these off-gasses, through simulating the potential and additional power generation effect that could have occurred for a typical plant´s manual operating procedure and an optimization control algorithm. The investigation is founded on the results from these two different simulation approaches. Simulated results showed that operations under the control algorithm would have yielded a 3.67% increase in power generation, when compared to the plant´s current operating philosophy. Under the assumption of an additional 65 tonlh boiler house and an extra 15MW turbine, simulation results showed a potential power generation increase of 25.19% under the plant operational procedure, when compared to initial plant set up. The control algorithm yielded an additional 34.39% increase in power generation over the investigated time period. In all but one simulation scenario did the control algorithm result in less turbine trips. All simulations are based on real world data.