Combined-Cycle Power Stations Using “Clean-Coal Technologies”: Thermodynamic Analysis of Full Gasification Versus Fluidized Bed Combustion With Partial Gasification

1996 ◽  
Vol 118 (4) ◽  
pp. 737-748 ◽  
Author(s):  
G. Lozza ◽  
P. Chiesa ◽  
L. DeVita
Keyword(s):  
Fluidized Bed ◽  
Power Plants ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Carbon Conversion ◽  
Fluidized Bed Combustion ◽  
Power Stations ◽  
Attractive Option ◽  
Partial Gasification ◽  
Partial Coal Gasification

A novel class of power plants for clean conversion of coal into power has been recently proposed, based on the concept of partial coal gasification and fluidized-bed combustion of unconverted char from gasification. This paper focuses on the thermodynamic aspects of these plants, in comparison with full gasification cycles, assessing their performance on the basis of a common advanced power plant technology level. Several plant configurations are considered, including pressurized or atmospheric fluidized-bed, air- or steam-cooled, with different carbon conversion in the gasifier. The calculation method, used for reproducing plant energy balances and for performance prediction, is described in the paper. A complete second-law analysis is carried out, pointing out the efficiency loss breakdown for both technologies. Results show that partial gasification plants can achieve efficiencies consistently higher than IGCC, depending on plant configuration and carbon conversion, making this solution a viable and attractive option for efficient coal utilization.

A Review of the Efficacy of Silicon Carbide Hot-Gas Filters in Coal Gasification and Pressurized Fluidized Bed Combustion Environments

1996 ◽  
Vol 118 (3) ◽  
pp. 500-506 ◽  
Author(s):  
R. R. Judkins ◽  
D. P. Stinton ◽  
J. H. DeVan
Keyword(s):  
Silicon Carbide ◽  
Fluidized Bed ◽  
Coal Gasification ◽  
Relevant Literature ◽  
Combined Cycle ◽  
Fluidized Bed Combustion ◽  
Gas Cleaning ◽  
Hot Gas ◽  
Hot Gas Cleaning ◽  
Pressurized Fluidized Bed Combustion

Reviews of relevant literature and interviews with individuals cognizant of the state of the art in ceramic filters for hot-gas cleaning were conducted. Thermodynamic calculations of the stability of various ceramic phases were also made. Based on these calculations, reviews, and interviews, conclusions were reached regarding the use of silicon carbide-based ceramics as hot-gas filter media. Arguments are presented that provide the basis for our conclusion that high-purity silicon carbide is a viable material in the integrated coal gasification combined cycle (IGCC) and pressurized fluidized-bed combustion (PFBC) environments we examined. Clay-bonded materials are, we concluded, suspect for these applications, their extensive use not-withstanding. Operations data we reviewed focused primarily on clay-bonded filters, for which a great deal of experience exists. We used the clay-bonded filter experience as a point of reference for our review and analysis.

Comparative Evaluation of Power Plants With Regard to Technical, Ecological and Economical Aspects

2001 ◽  
Author(s):  
Alex Lezuo ◽  
Robert Taud
Keyword(s):  
Life Cycle Cost ◽  
Power Plants ◽  
Coal Gasification ◽  
Time Frame ◽  
Combined Cycle ◽  
Fluidized Bed Combustion ◽  
Ecological Data ◽  
Economical Analysis ◽  
Generation Costs ◽  
Steam Parameters

The development of efficiency of gas turbine based combined cycle plants has been very fast during the last 10 years and has reached now a value of close to 60 %. This value is well above that of coal power plants or other technologies. Even though development has been going on in these fields as well. For a fairly comprehensive reorientation and status evaluation with the time frame of 2005 in focus, a comparative study with equal boundary conditions has been performed considering coal steam plants with various steam parameters, fluidized bed combustion, coal gasification and natural gas fired combined cycle plants. Besides investment also technical differences and ecological data are given. The final evaluation of power generation technologies is based however mainly on its electricity generation costs or life cycle cost. Considering today’s fuel prices and price development projections over the plant life times, an economical analysis has been performed and will be presented, serving also as framework for project and investment decisions.

A Review of the Efficacy of Silicon Carbide Hot Gas Filters in Coal Gasification and Pressurized Fluidized Bed Combustion Environments

1994 ◽  
Author(s):  
Roddie R. Judkins ◽  
David P. Stinton ◽  
Jackson H. DeVan
Keyword(s):  
Silicon Carbide ◽  
Fluidized Bed ◽  
Coal Gasification ◽  
Relevant Literature ◽  
Combined Cycle ◽  
Fluidized Bed Combustion ◽  
Gas Cleaning ◽  
Hot Gas ◽  
Hot Gas Cleaning ◽  
Pressurized Fluidized Bed Combustion

Reviews of relevant literature and interviews with individuals cognizant of the state-of-the-art in ceramic filters for hot-gas cleaning were conducted. Thermodynamic calculations of the stability of various ceramic phases were also made. Based on these calculations, reviews, and interviews, conclusions were reached regarding the use of silicon carbide-based ceramics as hot-gas filter media. Arguments are presented that provide the basis for our conclusion that high-purity silicon carbide is a viable material in the integrated coal gasification combined cycle (IGCC) and pressurized fluidized-bed combustion (PFBC) environments we examined. Clay-bonded materials are, we concluded, suspect for these applications, their extensive use notwithstanding. Operations data we reviewed focused primarily on clay-bonded filters, for which a great deal of experience exists. We used the clay-bonded filter experience as a point of reference for our review and analysis.

Thermal performance study for the coal-fired combined cycle with partial gasification and fluidized bed combustion

2001 ◽  
Vol 215 (4) ◽  
pp. 421-427 ◽  
Author(s):  
N Cai ◽  
T Yu ◽  
J Xiao ◽  
G Welford
Keyword(s):  
Fluidized Bed ◽  
Thermal Performance ◽  
Combined Cycle ◽  
Fluidized Bed Combustion ◽  
Performance Study ◽  
Integration System ◽  
Partial Gasification ◽  
Exergetic Analysis ◽  
Parametric Analyses ◽  
Pressurized Fluidized Bed Combustion

The coal-fired combined cycle with partial gasification and fluidized bed combustion (PGFBC-CC), also referred to as a hybrid cycle, has advantages of staged energy conversion and utilization, which can attain high thermal efficiency with low emissions. Four kinds of PGFBC-CC are studied in this paper, two based on pressurized fluidized bed combustion (PFBC) and two on atmospheric fluidized bed combustion (AFBC). Thermal performance calculations and parametric analyses were performed. On the basis of the results from the above analyses, the best integration system for China is suggested. In addition, a preliminary exergetic analysis is carried out for three of the PGFBC-CC variants.

Natural Gas Decarbonization to Reduce CO2 Emission From Combined Cycles—Part II: Steam-Methane Reforming

2000 ◽  
Vol 124 (1) ◽  
pp. 89-95 ◽  
Author(s):  
G. Lozza ◽  
P. Chiesa
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Partial Oxidation ◽  
Power Plants ◽  
Combined Cycle ◽  
Performance Estimation ◽  
Thermodynamic Efficiency ◽  
Methane Reforming ◽  
Operating Pressure ◽  
Carbon Conversion

This paper discusses novel schemes of combined cycle, where natural gas is chemically treated to remove carbon, rather than being directly used as fuel. Carbon conversion to CO2 is achieved before gas turbine combustion. The first part of the paper discussed plant configurations based on natural gas partial oxidation to produce carbon monoxide, converted to carbon dioxide by shift reaction and therefore separated from the fuel gas. The second part will address methane reforming as a starting reaction to achieve the same goal. Plant configuration and performance differs from the previous case because reforming is endothermic and requires high temperature heat and low operating pressure to obtain an elevated carbon conversion. The performance estimation shows that the reformer configuration has a lower efficiency and power output than the systems addressed in Part I. To improve the results, a reheat gas turbine can be used, with different characteristics from commercial machines. The thermodynamic efficiency of the systems of the two papers is compared by an exergetic analysis. The economic performance of natural gas fired power plants including CO2 sequestration is therefore addressed, finding a superiority of the partial oxidation system with chemical absorption. The additional cost of the kWh, due to the ability of CO2 capturing, can be estimated at about 13–14 mill$/kWh.

scholarly journals Ruhrchemie/Ruhrkohle’s Technical Version of the Texaco Coal Gasifier as Part of a Combined Cycle Plant

1982 ◽  
Author(s):  
B. Cornils ◽  
J. Hibbel ◽  
P. Ruprecht ◽  
R. Dürrfeld ◽  
J. Langhoff
Keyword(s):  
High Pressure ◽  
Power Plants ◽  
Coal Gasification ◽  
Operating Time ◽  
Combined Cycle ◽  
Gas Generation ◽  
Load Following ◽  
Gasification Process ◽  
Steady State Operation ◽  
Combined Cycle Plant

The Ruhrchemie/Ruhrkohle variant of the Texaco Coal Gasification Process (TCGP) has been on stream since 1978. As the first demonstration plant of the “second generation” it has confirmed the advantages of the simultaneous gasification of coal: at higher temperatures; under elevated pressures; using finely divided coal; feeding the coal as a slurry in water. The operating time so far totals 9000 hrs. More than 50,000 tons of coal have been converted to syn gas with a typical composition of 55 percent CO, 33 percent H2, 11 percent CO2 and 0.01 percent of methane. The advantages of the process — low environmental impact, additional high pressure steam production, gas generation at high pressure levels, steady state operation, relatively low investment costs, rapid and reliable turn-down and load-following characteristics — make such entrained-bed coal gasification processes highly suitable for power generation, especially as the first step of combined cycle power plants.

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