Hydrogen-Fired Steam Generation as an Alternative to Coal
Hydrogen-Fired Steam Generation is a patent-pending technology capable of driving megawatt-scale steam-turbine generator sets in commercial power plants, generating steam directly from the combustion of a fuel-mix composed of hydrogen and oxygen gases in stoichiometric proportion The intense heat generated is used to vaporize the water-flow necessary to drive the turbine, creating electricity as it turns the generator set. A brief overview of the technology, and the history of its development can be found here.
The only product of combustion is pure, virgin water, used directly in powering the turbine. There is no smokestack required, as there are no emissions of any kind, toxic or otherwise. In a typical Rankine Cycle power plant, the combustion of hydrogen-oxygen fuel-mix adds approximately 20% of the total water flow to the system on each pass.
While fuel-cell technology holds promise as a component in an energy storage and retrieval system for use in automobiles, homes and even some small business operations, its efficacy in a gigawatt-scale power plant is questionable at this time. Hydrogen-fired steam generation is the only technology available worldwide, capable of generating gigawatt-scale electric power from energy stored in the form of hydrogen and oxygen gases.
HFSG was originally developed as a fast-start, or black-start technology to enable conventional boiler-driven plants to produce power in the time it takes to warm a turbine to its operating state, while waiting the four- to six-hours it takes for the boiler to build a full head of steam. The recent increase in the number of coal-fired generating stations either decommissioned or scheduled to be so in the near future, presents an opportunity to deploy HFSG as an alternative to coal-fired operations, saving both power plant jobs and generation for downstream markets.
Coal-Fired Plant Conversion
Alternate steam path engineering utilizing HFSG technology can proceed in parallel to ongoing coal-fired operations, resulting in minimal interruption. Gas generation infrastructure must be located onsite, and typically will include a natural gas reforming furnace, and an air separation system to provide the hydrogen and oxygen supplies required to drive the turbine. An HFSG system is engineered for each turbine component of a modern, multi-stage unit, a computerized control unit providing optimum temperature and pressure conditions for each stage, as recommended by the manufacturer. Water supply to each stage is engineered to provide distilled water (post de-aeration, distal to the condenser infrastructure) to each stage according to the manufacturer's recommendation. When engineering is complete, tie-in can be accomplished in the time it takes for a normal, scheduled maintenance shut-down.
Once fully operational, all coal-delivery, -storage, -processing, -transport, and -combustion infrastructure can be removed from the site. The boiler infrastructure, fire-box and smokestack can also be removed, at which time site remediation can proceed to remove all traces of coal and fly ash.
Because the existing steam-turbine and generator set infrastructure can be driven by hydrogen fuel, the cost of conversion of coal-fired power plants is a mere fraction of the cost of total dismantling them, or converting them to gas-fired turbines.
Renewable Energy and Electrolyzer Generation of Hydrogen and Oxygen
Steam reforming and air separation technologies are quick to deploy, enabling continued power generation operations using HFSG. Air separation of oxygen is expensive however, and steam reformation of natural gas produces carbon-dioxide that must be abated. Fortunately, recent advances in bio-engineering hold significant promise in the field of carbon-dioxide conversion to fuels, but ideally gas generation without carbon-dioxide generation will better serve the needs of planet earth in the long run.
Once HFSG operations are underway, conversion of gas-generating processes to atmospheric electrolyzer generation should begin as soon as practical, in order to convert the plant to fully-renewable energy utilization. Manufacturing of commercial electrolyzer equipment appears to be limited to small-scale and test equipment in the United States. Tentative agreements are in place to begin producing large-scale atmospheric electrolyzer units here in America, under license from the European owners of the technology.
When a sufficient number of electrolyzer units is in place on-site, wind- and hydro-electric power purchased off-peak will generate enough hydrogen and oxygen fuel-stocks to power the plant during the day, when demand is high. The resulting output will be driven by fuel sourced from renewable energy, and thus will satisfy the requirements of most states' Renewable Energy Portfolios.
