Richard A. Newby

Final Report on the Development of a Hydrogen-Fueled Combustion Turbine Cycle for Power Generation

Through its New Energy and Industrial Technology Development Organization (NEDO) the Japanese government is sponsoring the World Energy Network (WE-NET) Program. WE-NET is a 28-year global effort to define and implement technologies needed for hydrogen-based energy systems. A critical part of this effort is the development of a hydrogen-fueled combustion turbine system to efficiently convert the chemical energy stored in hydrogen to electricity when hydrogen is combusted with pure oxygen. A Rankine cycle, with reheat and recuperation, was selected by Westinghouse as the general reference system. Variations of this cycle have been examined to identify a reference system having maximum development feasibility, while meeting the requirement of a minimum of 70, 9 percent low heating value (LHV) efficiency. The strategy applied by Westinghouse was to assess both a near-term and long-term Reference Plant. The near-term plant requires moderate development based on extrapolation of current steam and combustion turbine technology. In contrast, the long-term plant requires more extensive development for an additional high pressure reheat turbine, and is more complex than the near-term plant with closed-loop steam cooling and extractive feedwater heating. Trade-offs between efficiency benefits and development challenges of the near-term and long-term reference plant are identified. Results of this study can be applied to guide the future development activities of hydrogen-fueled combustion turbine systems.

A thermogravimetric study of the sulfation of limestone and dolomite — prediction of pressurized and atmospheric fluidized-bed desulfurization☆

Abstract A pressurized thermogravimetric (TG) analysis system was used to study the isothermal reaction of sulfur dioxide with limestone and dolomite at 1 and 10 atm pressure, and temperatures from 750 to 1050°C. Sorbents of 44–4000 μm particle size were sulfated in gases simulating a 10–300% excess air level in a coal combustion atmosphere. The TG rate data were used to predict the desulfurization performance of limestone and dolomite sorbents in atmospheric and pressurized fluidized-bed combustion systems. The projections are compared to available pilot plant data (i.e., the pressurized Exxon miniplant), and their limitations are discussed.

Coal/biomass fuels and the gas turbine: Utilization of solid fuels and their derivatives

This paper discusses key design and development issues in utilizing coal and other solid fuels in gas turbines. These fuels may be burned in raw form or processed to produce liquids or gases in more or less refined forms. The use of such fuels in gas turbines requires resolution of technology issues which are of little or no consequence for conventional natural gas and refined oil fuels. For coal, these issues are primarily related to the solid form in which coal is naturally found and its high ash and contaminant levels. Biomass presents another set of issues similar to those of coal. Among the key areas discussed are effects of ash and contaminant level on deposition, corrosion, and erosion of turbine hot parts, with particular emphasis on deposition effects.

Status of Westinghouse Hot Gas Filters for Coal and Biomass Power Systems

Several advanced, coal and biomass-based combustion turbine power generation technologies using solid fuels (IGCC, PFBC, Topping-PFBC, HIPPS) are currently under development and demonstration. A key developing technology in these power generation systems is the hot gas filter. These power generation technologies must utilize highly reliable and efficient hot gas filter systems iftheir full thermal efficiency and cost potential is to be realized. This paper reviews the recent test and design progress made by Westinghouse in the development and demonstration of hot gas ceramic barrier filters toward the goal of reliability. The objective of this work is to develop and qualify, through analysis and testing, practical hot gas ceramic barrier filter systems that meet the performance and operational requirements for these applications.

Development of a Hydrogen-Fueled Combustion Turbine Cycle for Power Generation

Consideration of a hydrogen based economy is attractive because it allows energy to be transported and stored at high densities and then transformed into useful work in pollution-free turbine or fuel cell conversion systems. Through its New Energy and Industrial Technology Development Organization (NEDO) the Japanese government is sponsoring the World Energy Network (WE-NET) Program. The program is a 28-year global effort to define and implement technologies needed for a hydrogen-based energy system. A critical part of this effort is the development of a hydrogen-fueled combustion turbine system to efficiently convert the chemical energy stored in hydrogen to electricity when the hydrogen is combusted with pure oxygen. The full-scale demonstration will be a greenfield power plant located sea-side. Hydrogen will be delivered to the site as a cryogenic liquid, and its cryogenic energy will be used to power an air liquefaction unit to produce pure oxygen.To meet the NEDO plant thermal cycle requirement of a minimum of 70.9%, low heating value (LHV), a variety of possible cycle configurations and working fluids have been investigated. This paper reports on the selection of the best cycle (a Rankine cycle), and the two levels of technology needed to support a near-term plant and a long-term plant. The combustion of pure hydrogen with pure hydrogen with pure oxygen results only in steam, thereby allowing for a direct-fired Rankine steam cycle. A near-term plant would require only moderate development to support the design of an advanced high pressure steam turbine and an advanced intermediate pressure steam turbine.© 1997 ASME

Fuel Gas Cleanup Parameters in Air-Blown IGCC

Fuel gas cleanup processing significantly influences overall performance and cost of IGCC power generation. The raw fuel gas properties (heating value, sulfur content, alkali content, ammonia content, tar content, particulate content) and the fuel gas cleanup requirements (environmental and turbine protection) are key process parameters. Several IGCC power plant configurations and fuel gas cleanup technologies are being demonstrated or are under development. In this evaluation, air-blown, fluidized-bed gasification combined-cycle power plant thermal performance is estimated as a function of fuel type (coal and biomass fuels), extent of sulfur removal required, and the sulfur removal technique. Desulfurization in the fluid bed gasifier is combined with external hot fuel gas desulfurization, or, alternatively with conventional cold fuel gas desulfurization, The power plant simulations are built around the Siemens Westinghouse 501F combustion turbine in this evaluation.

Large-scale fluidized bed physical model: methodology and results

Abstract Fluidized bed physical modeling principles are identified and applied to simulate a large-jetting fluidized bed. Physical (cold) model results from 30-cm and 3-m gasifier simulation units for initial bubble diameter, bubble frequency, gas leakage, bubble velocity, jet penetration depth and jet half-angle are correlated and compared with previous studies.

Use of Thermochemical Recuperation in Combustion Turbine Power Systems

The performance and practicality of heavy duty combustion turbine power systems incorporating thermochemical recuperation (TCR) of natural gas has been estimated to assess the potential merits of this technology. Process models of TCR combustion turbine power systems based on the Westinghouse 501F combustion turbine were developed to conduct the performance evaluation. Two TCR schemes were assessed — Steam-TCR and Flue Gas-TCR. Compared to conventional combustion turbine power cycles, the TCR power cycles show the potential for significant plant heat rate improvements, but their practicality is an issue. Significant development remains to verify and commercialize TCR for combustion turbine power systems.© 1997 ASME

A Direct Coal-Fired Combustion Turbine Power System Based on Slagging Gasification With In-Situ Gas Cleaning

Westinghouse began the development of a compact, entrained, slagging gasifier technology utilizing in-situ fuel gas cleaning for combustion turbine power cycles in 1986. The slagging gasifier is air-blown, and produces a hot, low-heating value fuel gas that can be combusted and quenched to combustion turbine inlet temperatures while maintaining low levels of NO x emissions. The U.S. Department of Energy sponsored engineering studies and pilot testing during the period 1986 to 1992. This work has shown that the technology has promise, although performance improvements are required in some key areas. A major challenge has been the development of in-situ removal of sulfur, alkali vapor, and particulate to low enough levels to permit its use in combustion turbine power systems without additional, external gas cleaning. This paper reviews the Westinghouse slagging gasifier, direct coal-fired turbine power generation concept; the pilot test results; and the current development activities that Westinghouse is engaged in.

An Evaluation of a Partial Oxidation Concept for Combustion Turbine Power Systems

In the partial oxidation concept, a high pressure, low-heating-value fuel gas is generated by partially combusting fuel with air. This fuel gas is expanded in a high-pressure turbine prior to being burned in a second-stage, conventional combustion turbine. This process reduces the specific air requirements of the power system and increases the power output. The performance, practicality, and cost of a heavy duty combustion turbine power system incorporating partial oxidation (PO) of natural gas has been estimated to assess the potential merits of this technology. Compared to conventional combustion turbine power cycles, the PO power cycle shows the potential for significant plant heat rate and cost-of-electricity improvements. However, significant development remains to verify and commercialize PO for combustion turbine power systems.Copyright