DESC0024069

C56-27b-273262In response to the Department of Energy’s Funding Opportunity Announcement number: 0002903, topic 27-b, “Methane Mitigation: Other”, the project team proposes to develop a novel heat recirculating combustor called Advanced Swiss-roll, along with a Model-Free Adaptive combustion control system that can achieve and maintain greater than 99% methane destruction efficiency over a wide range of operating conditions. The unique design of the advanced Swiss-roll-based enclosed combustion device enables high destruction efficiency, while maintaining fuel flexibility and energy efficiency and without the need of supplementary fuel or expensive catalysts. Methane is a powerful greenhouse gas with a global warming potential 80 times that of carbon dioxide, accounting for roughly 30% of global warming since pre-industrial times. Enclosed combustion devices are control equipment designed to safely and efficiently destroy methane and other volatile organic compounds generated during oil and gas operations. Although these devices are designed for flow rates corresponding to maximum upset conditions, they operate for long periods of time at loads as low as 10%. At low and unsteady flare gas flows, the combustion temperatures are not high enough to ensure complete thermal oxidation of methane and other volatile compounds present in the flare gas. This factor along with a lack of effective automatic combustion control systems lead to onsite destruction efficiency being much less than the Environmental Protection Agency’s mandate of 98%. The project team aims to address this challenge with the Advanced Swiss-roll technology, which uses effective heat recirculation to significantly increase the premixed combustion flammability. The proposed concept addresses the practical challenges of high turndown ratio and unsteady flare gas flow by using multiple air blowers and an optimized internal Swiss-roll design. This will enable a wider operating range, reduce response time, and lower auxiliary power consumption. Combined with the Model-Free Adaptive control system, the proposed system provides a cost-effective solution for methane mitigation and high destruction efficiency. The main technical benefits of this solution are: (1) Near 100% methane destruction efficiency due to high reaction temperatures and long residence times; (2) Very low Carbon Monoxide, Nitrogen Oxides, and unburnt hydrocarbons; (3) Advanced hydrodynamic design with lower pressure drop; (4) The Model-Free Adaptive control system can control the combustion chamber temperature to maintain high destruction efficiency under varying flare gas flow and thermal content; and (5) Operating environment has minimal effect on the operation of the enclosed combustion device. In Phase I, we will study the capabilities of the new two-blower advanced Swiss-roll design and prove the proposed concept with a Model-Free Adaptive combustion control on a sub-scale device. The collected data will be used for modeling, designing the full-scale, advanced Swiss-roll, and further improving the technology for higher flare gas flows. Phase II will include a full-scale advanced Swiss-roll system with a refined Model-Free Adaptive control aimed at small-to-medium-size gas flares. At the end of Phase II, the team with develop a market-ready enclosed combustion device based on the advanced Swiss-roll and Model-Free Adaptive control system that will guarantee >99% destruction efficiency over variable conditions including changing gas composition and flow rates.