Interest in hydrogen as a primary fuel stream in heavy-duty gas turbine engines has increased as pre-combustion carbon capture and sequestration (CCS) has become a viable option for integrated gasification combined cycle (IGCC) power plants. The US Department of Energy has funded the Advanced IGCC/Hydrogen Gas Turbine Program since 2005 with an aggressive plant-level NOx target of 2 ppm @ 15% O2 for an advanced gas turbine cycle. Approaching this NOx level with highly-reactive hydrogen fuel at the conditions required is a formidable challenge that requires novel combustion technology. This study begins by measuring entitlement NOx emissions from perfectly-premixed combustion of the high-hydrogen fuels of interest. A new premixing fuel injector for high-hydrogen fuels was designed to balance reliable, flashback-free operation, reasonable pressure drop, and low emissions. The concept relies on distributed, small-scale jet-in-crossflow mixing that is a departure from traditional swirl-based premixing concepts. Single nozzle rig experiments were conducted at pressures of 10 atm and 17 atm, with air preheat temperatures of about 650K. With nitrogen-diluted hydrogen fuel, characteristic of carbon-free syngas, stable operation without flashback was conducted up to flame temperatures of approximately 1850K. In addition to the effects of operating pressure, the impact of minor constituents in the fuel — carbon monoxide, carbon dioxide, and methane — on flame holding in the premixer is presented. The new fuel injector concept has been incorporated into a full-scale, multi-nozzle combustor can with an energy conversion rate of more than 10 MW at F-class conditions. The full-can testing was conducted at full gas turbine conditions and various fuel compositions of hydrogen, natural gas, and nitrogen. This combustion system has accumulated over 100 hours of fired testing at full-load with hydrogen comprising over 90 percent of the reactants by volume. NOx emissions (ppm) have been measured in the single digits with hydrogen-nitrogen fuel at target gas turbine pressure and temperatures. Results of the testing show that small-scale fuel-air mixing can deliver a reliable, low-NOx solution to hydrogen combustion in advanced gas turbines.

Interest in hydrogen as a primary fuel stream in heavy-duty gas turbine engines has increased as precombustion carbon capture and sequestration (CCS) has become a viable option for integrated gasification combined cycle (IGCC) power plants. The U.S. Department of Energy has funded the Advanced IGCC I Hydrogen Gas Turbine Program since 2005 with an aggressive plant-level NO^ target of 2 ppm at 15% O2for an advanced gas turbine cycle. Approaching this NO^ level with highly reactive hydrogen fuel at the conditions required is a formidable challenge that requires novel combustion technology. This study begins by measuring entitlement NO^ emissions from perfectly premixed combustion of the high-hydrogen fuels of interest. A new premixing fuel injector for highhydrogen fuels was designed to balance reliable flashback-free operation, reasonable pressure drop, and low emissions. The concept relies on small-scale jet-in-crossflow mixing that is a departure from traditional swirl-based premixing concepts. Single nozzle rig experiments were conducted at pressures of 10 atm and 17 atm, with air preheat temperatures of about 650 K. With nitrogen-diluted hydrogen fuel, characteristic of carbon-free syngas, stable operation without flashback was conducted up to flame temperatures of approximately 1850 K. In addition to the effects of pressure, ihe impacts of nitrogen dilution levels and amounts of minor constituents in ihe fuel-carbon monoxide, carbon dioxide, and methane-on flame holding in the premixer are presented. The new fuel injector concept has been incorporated into a full-scale, multinozzle combustor can with an energy conversion rate of more than 10 MW at F-class conditions. The full-can testing was conducted at full gas turbine conditions and various fuel compositions of hydrogen, natural gas, and nitrogen. This combustion system has accumulated over 100 h of fired testing at full load with hydrogen comprising over 90% of the reactants by volume. NOê missions (ppm) have been measured in the single digits with hydrogen-nitrogen fuel at target gas turbine pressure and temperatures. Results of the testing show that small-scale fuel-air mixing can deliver a reliable, low-NO^ solution to hydrogen combustion in advanced gas turbines.

Progress on the joint GE Energy/US Department of Energy (DOE) High Hydrogen Turbine Program is presented. A summary of GE’s current integrated gasification combined cycle (IGCC) experience is provided. The Phase I approach is discussed with selected results included. The program follows the well-established GE approach to introducing new technology through: fundamental laboratory testing and analysis; subscale demonstration; full-scale development; full-scale verification. Advancements towards the ultimate goal of ultralow NOx emissions with coal derived pre-combustion carbon capture fuels are presented. Feasibility of diluent-free low NOx combustion is demonstrated experimentally at gas turbine conditions with representative fuel compositions. Phase II design challenges are highlighted within the framework of Phase I results.

Future high-efficiency, low-emission generation plants that produce electric power, transportation fuels, and/or chemicals from fossil fuel feed stocks require a new class of fuelflexible combustors. In this program, a validated combustor approach was developed which enables single-digit NO x operation for a future generation plants with low-Btu off gas and allows the flexibility of process-independent backup with natural gas. This combustion technology overcomes the limitations of current syngas gas turbine combustion systems, which are designed on a site-by-site basis, and enable improved future co-generation plant designs. In this capacity, the fuel-flexible combustor enhances the efficiency and productivity of future co-production plants.In task 2, a summary of market requested fuel gas compositions was created and the syngas fuel space was characterized. Additionally, a technology matrix and chemical kinetic models were used to evaluate various combustion technologies and to select two combustor concepts. In task 4 systems analysis of a co-production plant in conjunction with chemical kinetic analysis was performed to determine the desired combustor operating conditions for the burner concepts.Task 5 discusses the experimental evaluation of three syngas capable combustor designs. The hybrid combustor, Prototype-1 utilized a diffusion flame approach for syngas fuels with a lean premixed swirl concept for natural gas fuels for both syngas and natural gas fuels at FA+e gas turbine conditions. The hybrid nozzle was sized to accommodate syngas fuels ranging from ~100 to 280 btu/scf and with a diffusion tip geometry optimized for Early Entry Co-generation Plant (EECP) fuel compositions. The swozzle concept utilized existing GE DLN design methodologies to eliminate flow separation and enhance fuel-air mixing. With changing business priorities, a fully premixed natural gas & syngas nozzle, Protoytpe-1N, was also developed later in the program. It did not have the diluent requirements of Prototype-1 and was demonstrated at targeted gas turbine conditions. The TVC combustor, Prototype-2, premixes the syngas with air for low emission performance. The combustor was designed for operation with syngas and no additional diluents. The combustor was successfully operated at targeted gas turbine conditions. Another goal of the program was to advance the status of development tools for syngas systems. In Task 3 a syngas flame evaluation facility was developed. Fundamental data on syngas flame speeds and flame strain were obtained at pressure for a wide range of syngas fuels with preheated air. Several promising reduced order kinetic mechanisms were compared with the results from the evaluation facility. The mechanism with the best agreement was selected for application to syngas combustor modeling studies in Task 6. Prototype-1 was modeled using an advanced LES combustion code.The tools and combustor technology development culminate in a full-scale demonstration of the most promising technology in Task 8. The combusto...