Showing papers on "Integrated gasification combined cycle published in 2006"

Effect of Pressure on the Behavior of Copper-, Iron-, and Nickel-Based Oxygen Carriers for Chemical-Looping Combustion

Abstract: The combustion process integrated by coal gasification and chemical-looping combustion (CLC) could be used in power plants with a low energy penalty for CO2 capture. This work analyzes the main characteristics related to the CLC process necessary to use the syngas obtained in an integrated gasification combined cycle (IGCC) power plant. The kinetics of reduction with H2 and CO and oxidation with O2 of three high-reactivity oxygen carriers used in the CLC system have been determined in a thermogravimetric analyzer at atmospheric pressure. The iron- and nickel-based oxygen carriers were prepared by freeze-granulation, and the copper-based oxygen carrier was prepared by impregnation. The changing grain size model (CGSM) was used for the kinetic determination, assuming spherical grains for the freeze-granulated particles containing iron and nickel and a platelike geometry for the reacting surface of the copper-based impregnated particles. The dependence of the reaction rates on temperature was low, with the a...

High-temperature air/steam-blown gasification of coal in a pressurized spout-fluid bed

Abstract: The concept of high-temperature air/steam-blown gasification technology for converting coal into low-caloric-value gas for power generation is proposed and evaluated experimentally. Preliminary experiments are performed in a 0.1 MW thermal input pressurized spout-fluid bed gasifier. The influences of the gasifying agent preheat temperature, the gasification temperature and pressure, the equivalence ratio, the ratio of steam-to-coal on gas composition, gas higher heating value, carbon conversion, and cold gas efficiency are examined. The experimental results prove the feasibility of high-temperature air/steam-blown gasification process. The gas heating value is increased by 23%, when the gasifying agent temperature is increased from 300 to 700 °C. For the operation conditions studied, the results show that gasification temperature is the most important factor influencing coal gasification in the spout-fluid bed. The gasifier performance is improved at elevated pressure mainly due to the better fluidization...

Plant And Process For Removing Carbon Dioxide From Gas Streams

Abstract: The present invention is based on the realization that the carbon dioxide component of industrial gas streams also containing steam can be processed so to utilize either as latent and/or sensible heat the heat available from the steam component to assist in separating carbon dioxide from the remainder of the gas stream. For example, flue gases produced by power stations burning brown coal, black coal or natural gas inherently contain a useful amount of energy that can be harnessed according to the present invention. According to particular preferred forms of the invention, nitrogen and sulphur constituent such as SOx and NOx, H2S and other nitrogen containing compounds may also be removed from the gas stream through direct contact with the absorbing medium and used to produce by-products such as fertiliser material.

Sorbents for Mercury Capture from Fuel Gas with Application to Gasification Systems

Abstract: In regard to gasification for power generation, the removal of mercury by sorbents at elevated temperatures preserves the higher thermal efficiency of the integrated gasification combined cycle system. Unfortunately, most sorbents display poor capacity for elemental mercury at elevated temperatures. Previous experience with sorbents in flue gas has allowed for judicious selection of potential high-temperature candidate sorbents. The capacities of many sorbents for elemental mercury from nitrogen, as well as from four different simulated fuel gases at temperatures of 204−371 °C, have been determined. The simulated fuel gas compositions contain varying concentrations of carbon monoxide, hydrogen, carbon dioxide, moisture, and hydrogen sulfide. Promising high-temperature sorbent candidates have been identified. Palladium sorbents seem to be the most promising for high-temperature capture of mercury and other trace elements from fuel gases. A collaborative research and development agreement has been initiated...

High temperature electrolysis for syngas production

Abstract: Syngas components hydrogen and carbon monoxide may be formed by the decomposition of carbon dioxide and water or steam by a solid-oxide electrolysis cell to form carbon monoxide and hydrogen, a portion of which may be reacted with carbon dioxide to form carbon monoxide One or more of the components for the process, such as steam, energy, or electricity, may be provided using a nuclear power source

Improved System Integration for Integrated Gasification Combined Cycle (IGCC) Systems

Abstract: Integrated gasification combined cycle (IGCC) systems are a promising technology for power generation. They include an air separation unit (ASU), a gasification system, and a gas turbine combined cycle power block, and feature competitive efficiency and lower emissions compared to conventional power generation technology. IGCC systems are not yet in widespread commercial use and opportunities remain to improve system feasibility via improved process integration. A process simulation model was developed for IGCC systems with alternative types of ASU and gas turbine integration. The model is applied to evaluate integration schemes involving nitrogen injection, air extraction, and combinations of both, as well as different ASU pressure levels. The optimal nitrogen injection only case in combination with an elevated pressure ASU had the highest efficiency and power output and approximately the lowest emissions per unit output of all cases considered, and thus is a recommended design option. The optimal combination of air extraction coupled with nitrogen injection had slightly worse efficiency, power output, and emissions than the optimal nitrogen injection only case. Air extraction alone typically produced lower efficiency, lower power output, and higher emissions than all other cases. The recommended nitrogen injection only case is estimated to provide annualized cost savings compared to a nonintegrated design. Process simulation modeling is shown to be a useful tool for evaluation and screening of technology options.

System and method for generation of high pressure air in an integrated gasification combined cycle system

Abstract: An integrated gasification combined cycle system. In one embodiment (FIG. 2 ) a system ( 200 ) includes an ion transport membrane air separation unit ( 210 ) for producing oxygen-enriched gas ( 209 ) and oxygen-depleted air ( 227 ), a gasification system ( 5 ) for generating syngas with the oxygen-enriched gas ( 209 ), a gas combustor ( 234 ) for reacting the syngas ( 224 ), and a subsystem configured to provide a first stream of air to the combustor ( 234 ) at a first pressure and to provide a second stream of air to the air separation unit ( 210 ) at a second pressure greater than the first pressure. The subsystem includes a compressor ( 230 ) having multi-pressure outlets ( 203, 204 ).

The role of a coal gasification fly ash as clay additive in building ceramic

Abstract: The clean coal integrated gasification in combined cycle (IGCC) technology of electrical power generation is different than conventional process in combustible treatment which generates inorganic wastes in the form of glassy slag and fly ash with singular properties We have studied the fly ash coming from ELCOGAS IGCC power plant as additive to clays for building ceramic fabrication The addition of this new kind of fly ash to a clay of medium plasticity to elaborate pressed specimens, that were baked at 900 °C, improves the sintering of the paste and consequently an improvement of absorption, saturation and mechanical properties of the fired bodies, with no negative effects on shrinkage, colour alteration or efflorescence In contrast, this fly ash does not mend the excessive firing shrinkage when added to a clay of a high plasticity index

Utilization of carbon dioxide from coal-fired power plant for the production of value-added products

Abstract: 2

Integrated coal gasification combined cycle plant

Abstract: An IGCC plant which can improve the power generation efficiency and which can suppress the emission of sulfur components and dust into the atmosphere is provided. The IGCC plant described above has a coal gasifier for converting pulverized coal to a syngas; an exhaust heat recovery boiler generating steam; a gas turbine system which is operated by the syngas and which supplies a combustion exhaust gas to the exhaust heat recovery boiler; a steam turbine system operated by the steam generated by the exhaust heat recovery boiler; a power generator connected to the gas turbine system and/or the steam turbine system; a desulfurization device for removing sulfur components from the combustion exhaust gas discharged from the exhaust heat recovery boiler; and a wet-type electric precipitator for removing sulfur components and dust.

Technology options for capturing CO2

Abstract: Concerns about global climate change have prompted interest in reducing or eliminating the carbon dioxide (CO 2 ) emissions of fossil fuel-fired power plants. Here's a guide to the technology and economics of three CO 2 capture methods: postcombustion separation of CO 2 from flue gas (applicable to existing plants), and oxygen-fired combustion and precombustion capture (suitable for new coal-fired capacity, including IGCC plants).

Syngas capable combustion systems development for advanced gas turbines

Abstract: In the age of volatile and ever increasing natural gas fuel prices, strict new emission regulations and technological advancements, modern IGCC plants are the answer to growing market demands for efficient and environmentally friendly power generation. IGCC technology allows the use of low cost opportunity fuels, such as coal, of which there is a more than a 200-year supply in the U.S., and refinery residues, such as petroleum coke and residual oil. Future IGCC plants are expected to be more efficient and have a potential to be a lower cost solution to future CO2 and mercury regulations compared to the direct coal fired steam plants. Siemens has more than 300,000 hours of successful IGCC plant operational experience on a variety of heavy duty gas turbine models in Europe and the U.S. The gas turbines involved range from SGT5-2000E to SGT63000E (former designations are shown on Table 1). Future IGCC applications will extend this experience to the SGT5-4000F and SGT6-4000F/5000F/6000G gas turbines. In the currently operating Siemens’ 60 Hz fleet, the SGT6-5000F gas turbine has the most operating engines and the most cumulative operating hours. Over the years, advancements have increased its performance and decreased its emissions and life cycle costs without impacting reliability. Development has been initiated to verify its readiness for future IGCC application including syngas combustion system testing. Similar efforts are planned for the SGT6-6000G and SGT5-4000F/SGT6-4000F models. This paper discusses the extensive development programs that have been carried out to demonstrate that target emissions and engine operability can be achieved on syngas operation in advanced F-class 50 Hz and 60 Hz gas turbine based IGCC applications.

Advanced ASU and HRSG integration for improved integrated gasification combined cycle efficiency

Abstract: A system and method for increasing the efficiency and/or power produced by an integrated gasification combined cycle system by increasing the integration between the air separation unit island, the heat recovery steam generator and the remainder of the system. By integrating heat produced by the heat recovery steam generator in the remainder of the integrated gasification combined cycle system, heat may be utilized that may have otherwise been lost or used further downstream in the system. The integration helps to increase the efficiency of the combustion reaction and/or the gasification reaction used to produce the syngas utilized in the integrated gasification combined cycle system.

Energy and economic assessment of IGCC power plants integrated with DME synthesis processes

Abstract: The combined production of dimethylether (DME) and electrical energy in Integrated Gasification Combined Cycle (IGCC) power plants is a very attractive option for exploiting the world's hug...

An Overview of Turbine and Combustor Development for Coal-Based Oxy-Syngas Systems

Abstract: Coal combustion technology is required that is capable of: (1) co-producing electricity and hydrogen from coal while; (2) achieving high efficiency, low capital cost, low operating cost, and near-zero atmospheric emissions; and (3) producing a sequestration-ready carbon dioxide stream. Clean Energy Systems, Inc. (CES) and Siemens Power Generation, Inc., are developing this technology that would lead to a 300 to 600 MW, design for a zero emissions coal syngas plant, targeted for the year 2015, CES and Siemens received awards on September 30, 2005 from the U.S. Department of Energy’s; Office of Fossil Energy Turbine Technology R&D Program. These awards are designed to advance turbines and turbine subsystems for integrated gasification combined cycle (IGCC) power plants. Studies have shown [1–4] that replacing air with nearly pure oxygen and steam in a turbine’s combustion chamber is a promising approach to designing coal based power plants with high efficiency and near-zero emissions. Siemens will combine current steam and gas turbine technologies to design an optimized turbine that uses oxygen with coal derived hydrogen fuels in the combustion process under a DOE Turbine Development Project [5]. CES will develop and demonstrate a new combustor technology powered by coal syngas and oxygen under a DOE Combustor Development Project [6]. The proposed programs build upon twelve years of prior technical work and government-sponsored research to develop and demonstrate zero-emission fossil fuel power generation. The planned system studies build upon previous work conducted by private, public, and foreign organizations, including CES [7–9], DOE’s National Energy Technology Laboratory (NETL) [10–12], Air Liquide (AL) [1,13], Lawrence Livermore National Laboratory (LLNL) [2], Fern Engineering, Inc. [14], and Japanese investigators [15, 16]. Other pertinent data related to coal gasification, advanced air separation unit (ASU), plant integration and plant systems optimization, etc., can be found in references [17–23].Copyright © 2006 by ASME

Fuels and electricity from biomass with CO2 capture and storage

Abstract: Mass/energy balances and financial analysis are presented for (1) plants co-producing Fischer- Tropsch diesel and gasoline blendstocks plus electricity from biomass and (2) biomass integrated gasification combined cycle power plants. Plant designs with and without carbon capture and storage are analyzed. The feedstock is switchgrass. For plants with CO2 capture, we assume that the CO2 is stored in deep saline aquifers or used for enhanced oil recovery. Sustainably produced biomass is an essentially carbon-neutral energy source since the CO2 emitted from its use as energy is of recent photosynthetic origin. By capturing and storing below ground some carbon from biomass during its conversion to fuel or electricity, this biomass becomes a negative CO2-emitting energy supply. This paper summarizes and extends detailed analyses (1,2) of mass/energy balances and economics for plants that co-produce Fischer-Tropsch (FT) diesel and gasoline blendstocks plus electricity from biomass, with and without carbon capture and storage (CCS). Stand-alone biomass integrated gasification combined cycle (IGCC) power generation with and without CCS is similarly analyzed. For plants with CCS, overall economics are explored assuming the CO2 is stored in deep saline aquifers or used for enhanced oil recovery (EOR). The feedstock is switchgrass, a perennial grass native to the Great Plains of the USA that is a promising future bioenergy crop (3,4). Methodology We use Aspen Plus software to help design the FT and IGCC plants and calculate mass/energy balances. Some equipment components in our plants are not commercially available today but can be expected to be so in the 2010-2015 timeframe. To help understand the potential for these biomass conversion systems in this timeframe and beyond, our process simulations assume that key achievable technology advances are, in fact, realized. These include feeding of switchgrass to a pressurized fluidized-bed gasifier, reliable high-efficiency oxygen-blown fluidized-bed gasification, complete tar cracking in a separate vessel following gasification, and gas cleanup to specifications for downstream synthesis or gas turbine combustion. We consider a switchgrass feed rate of 5,669 tonnes per day (20% moisture as received), or 4535 dry tonnes per day. This scale of bioenergy conversion is larger than most prior analyses have considered, although biomass processing facilities this size and larger are operating commercially today (e.g., some Brazilian sugarcane mills). When switchgrass is produced as an agricultural crop, average transport distances will be relatively modest for delivering feedstock to conversion facilities of the size we consider here. In earlier work we have shown that up to very large conversion plant sizes, the impact on overall economics of increasing average delivered feedstock costs with increasing plant sizes is more than offset by scale-economy gains in the capital cost of the larger conversion facilities (5). All plants include chopping of the switchgrass, followed by oxygen-blown fluidized-bed gasification, gas cooling and gas cleanup. In our IGCC design with CCS (IGCC-C), CO2 is removed with Rectisol technology following water gas shift (WGS), after which the remaining hydrogen-rich syngas is burned in a gas turbine combined cycle. With CO2 venting (IGCC-V), no

Carbon dioxide capture and geological storage: research, development and application in Australia

Abstract: Projections of world energy demand indicate increasing use of fossil fuels, especially coal. Because of this there is interest in using carbon dioxide capture and storage technologies as a mitigation option, particularly in Australia because of its dependency on fossil fuels for electricity generation. Research in Australia into capture options includes post-combustion capture (PCC), integrated gasification combined cycle (IGCC) and oxyfuels combustion. Separation technologies being investigated in Australia include solvent absorption, membranes, adsorption and cryogenics, with particular emphasis on bringing down costs. Australia appears to have abundant geological storage capacity, particularly in saline formations and to a much lesser extent in depleted oil and gas fields. Storage in coal systems has potential but more research and development is needed. Australia has the opportunity to use low-emission hubs in order to bring down costs. A major study of this concept for the Latrobe Valley of Victoria,...

High Temperature Steam and Air Gasification of Non-woody Biomass Wastes

Abstract: Gasification of non-woody biomass wastes has been conducted experimentally to examine the effect of gasification agent temperature and waste composition on the product gas composition with special focus on the amounts of hydrogen produced. The temperature and chemical composition of gasification agent was controlled using a premixed burner and water injection into the high temperature zone of the flame. Increase in gasifying agent temperature enhanced the volume and heating value of the syngas using pure steam or air/steam as the gasifying agent. Pure steam gasification produced more H2, CO and CH4 as compared to air/steam case, in particular at low gasification temperatures. The gasification characteristic of all the biomass wastes examined was similar and depends on the biomass fuel composition. Gasification at higher temperatures resulted in more hydrogen yield in the product stream. The quality of steam used had an important effect on the syngas composition. Much higher yields of hydrogen can be achieved using ultra high temperature steam with negligible amounts of tars and hydrocarbons in the syngas.

Estimating Future Costs of CO2 Capture Systems Using Historical Experience Curves

Abstract: Reductions in the cost of technologies as a result of learning-by-doing, RD coal-based integrated gasification combined cycle (IGCC) plants with precombustion capture; and coal-fired oxyfuel combustion for a new PC plants. We assess the rate of cost reductions achieved by other process technologies in the past, and by analogy with capture plant components estimate future cost reductions that might be achieved by power plants employing CO2 capture. Effects of uncertainties in key parameters on projected cost reductions also are evaluated via sensitivity analysis.

Method for increasing the efficiency of a combined gas/steam power station with integrated gasification combined cycle

Abstract: The invention relates to a method for increasing the efficiency of a combined gas/steam power station (10) with integrated gasification combined cycle. Said power station comprises a gas turbine compressor (14) and an air-separation unit (18) having a defined working pressure. Compressed air is removed from the gas turbine compressor (14) at a pressure level that is adapted to the working pressure of the air-separation unit (18). The removed air is then supplied to the air-separation unit (18) where the air is broken down into its individual constituents, especially oxygen and nitrogen. The nitrogen produced in the air-separation unit (18) is removed from the air-separation unit and at least a part of the removed nitrogen quantity is used as a coolant in the gas/steam power station in order to improve its efficiency.