Estimation of cold gas efficiency and reactor size of low-temperature gasifier for advanced-integrated coal gasification combined cycle systems

2019 ◽  
Vol 193 ◽  
pp. 304-316 ◽  
Author(s):  
Yusuke Furusawa ◽  
Haruka Taguchi ◽  
Siti Norazian Ismail ◽  
Sivasakthivel Thangavel ◽  
Koichi Matsuoka ◽  
...  
Author(s):  
Dandan Wang ◽  
Sheng Li ◽  
Lin Gao

In this paper, a novel coal gasification technology used for Integrated Gasification Combined Cycle (IGCC) power plants is proposed, in which a regenerative unit is applied to recover syngas sensible heat to generate steam and then the high temperature steam is used to gasify coke from pyrolyzer. Through such a thermochemical regenerative unit, the sensible heat with lower energy level is upgraded into syngas chemical energy with higher energy level, and therefore a higher cold gas efficiency (CGE) is expected. The Aspen Plus Software is selected to simulate the novel coal gasification system. Then the exergy and Energy-Utilization Diagram (EUD) analyses are applied to disclose the plant performance enhancement mechanism. It reveals that 83.2% of syngas sensible heat can be recovered into steam agent and so the CGE is upgraded to 90%. And with the enhancement of CGE, the efficiency of an IGCC plant based on the novel gasification system can be as high as 51.82%, showing a significant improvement compared to 45.2% in a Texaco coal gasification based plant. At the same time, the exergy destruction of gasification process is reduced from 132.5MW to 98.4MW through thermochemical reactions. Lift of accepted energy level (Aea), and decrease of released energy level (Aed) and heat absorption (ΔH) contribute to the exergy destruction reduction in the gasification process. Additionally, since oxygen agent is no longer used in the IGCC, 34.5MW exergy loss in the air separation unit is avoided. Thereby the novel coal gasification technology proposed in this paper has a good thermodynamic performance and may provide a quite promising way for high efficient and clean coal utilization.


Author(s):  
Orlando M. Ramirez ◽  
Lesme Corredor

Coal is the most interesting gasification resource in commercial application due to its wide reserves and low prices, therefore numerous commercial coal gasification technologies have been developed. The features of the most important have been studied in this paper. The gasifiers considered are the British Gas Lurgi, Siemens, General Electric, Conoco Phillips and Shell; principal parameters have been taken into account such as the cold gas efficiency, the production capacity, oxygen, electricity and steam consumption, effect of coal type, syngas produced for the desired final product, capital, operation costs, and environmental performance. From assessment of the latter features for each gasifier, one can conclude that although the BGL has the lowest production capacity with 1000 tons/day, it represents the best technology option due to its highest cold gas efficiency of 89%, the lowest oxygen and electricity consumption and the lowest capital costs with 50 million dollars per unit.


Author(s):  
Osamu Kurata ◽  
Risa Nomura ◽  
Norihiko Iki ◽  
Masako Kawabata ◽  
Atsushi Tsutsumi ◽  
...  

Integrated Coal Gasification Fuel Cell Combined Cycle (IGFC) is expected to be the most efficient power generation system in coal fired power generation systems [1,2]. We have been analyzing the processes of Advanced IGFC (A-IGFC) [3] which is expected to be realized in 2040. The Advanced IGFC (A-IGFC) system can reduce the exergy loss resulting from combustion, and its ‘exergy recuperation’ [4] is appealing. The waste heat exhausted from the fuel cells is recycled to the gasifier for steam reforming in an endothermic reaction with a low exergy loss and a high cold gas efficiency. Our current study focuses on the optimization of the unit configurations of the A-IGFC including gasifier, compressor, solid oxide fuel cell (SOFC), combustor, gas turbine, heat recovery steam generator (HRSG), and steam turbine. The process simulator HYSYS®.Plant (Aspen technology Inc.) is employed in order to express the gasifier, the SOFC and the other units. The process of reforming with steam means recycled steam stream in the HYSYS® model. In the previous study [3] we found that many recycled material streams and recycled steam in the AIGFC process prevent convergence of solver. It is shown that comparison of simulation program, a trial analysis of the AIGFC process using HYSYS.Plant and the problems about convergence of solver.


2020 ◽  
Vol 209 ◽  
pp. 03011
Author(s):  
Igor Donskoy

In this work, we studied the efficiency of the coal gasification process under oxyfuel conditions. Using mathematical modelling one-dimensional stationary statement, the optimal parameters of coal processing were determined, air and oxyfuel conditions are compared. The calculated dependences of the characteristics of the gasification process on the stoichiometric ratio at different initial temperatures are constructed. The optimal values of oxygen stoichiometric ratio and the maximum values of cold gas efficiency in the selected range of parameters are determined. The contribution of the thermophysical and reactive properties of the gasification agent to the change in the cold gas efficiency is estimated.


Author(s):  
Eric Liese

This paper examines the arrangement of a solid oxide fuel cell (SOFC) within a coal gasification cycle, this combination generally being called an integrated gasification fuel cell cycle. This work relies on a previous study performed by the National Energy Technology Laboratory (NETL) that details thermodynamic simulations of integrated gasification combined cycle (IGCC) systems and considers various gasifier types and includes cases for 90% CO2 capture (2007, “Cost and Performance Baseline for Fossil Energy Plants, Vol. 1: Bituminous Coal and Natural Gas to Electricity,” National Energy Technology Laboratory Report No. DOE/NETL-2007/1281). All systems in this study assume a Conoco Philips gasifier and cold-gas clean up conditions for the coal gasification system (Cases 3 and 4 in the NETL IGCC report). Four system arrangements, cases, are examined. Cases 1 and 2 remove the CO2 after the SOFC anode. Case 3 assumes steam addition, a water-gas-shift (WGS) catalyst, and a Selexol process to remove the CO2 in the gas cleanup section, sending a hydrogen-rich gas to the fuel cell anode. Case 4 assumes Selexol in the cold-gas cleanup section as in Case 3; however, there is no steam addition, and the WGS takes places in the SOFC and after the anode. Results demonstrate significant efficiency advantages compared with IGCC with CO2 capture. The hydrogen-rich case (Case 3) has better net electric efficiency compared with typical postanode CO2 capture cases (Cases 1 and 2), with a simpler arrangement but at a lower SOFC power density, or a lower efficiency at the same power density. Case 4 gives an efficiency similar to Case 3 but also at a lower SOFC power density. Carbon deposition concerns are also discussed.


1985 ◽  
Vol 64 (9) ◽  
pp. 716-733
Author(s):  
Takehiko FURUSAWA ◽  
Toshinori KOJIMA ◽  
Seiji TOKAWA ◽  
Shuichi TANAKA ◽  
Takuya KAWANISHI ◽  
...  

Author(s):  
W. P. Parks ◽  
R. R. Ramey ◽  
D. C. Rawlins ◽  
J. R. Price ◽  
M. Van Roode

A Babcock and Wilcox - Solar Turbines Team has completed a program to assess the potential for structural ceramic composites in turbines for direct coal-fired or coal gasification environments. A review is made of the existing processes in direct coal firing, pressurized fluid bed combustors, and coal gasification combined cycle systems. Material requirements in these areas were also discussed. The program examined the state-of-the-art in ceramic composite materials. Utilization of ceramic composites in the turbine rotor blades and nozzle vanes would provide the most benefit. A research program designed to introduce ceramic composite components to these turbines was recommended.


Author(s):  
Rongbin Li ◽  
Mingzhuang Xie ◽  
Hui Jin ◽  
Liejin Guo ◽  
Fengqin Liu

AbstractThe three-dimensional (3-D) comprehensive mathematical model was developed to simulate the coal gasification process in an entrained flow gasifier with a swirl burner. The models employed or developed includes the coal devolatilization model, the char combustion and gasification model, the gas homogeneous reaction model, the random-trajectory model, gas turbulence model, and the P-1 radiation model. The solution of models was executed based on the computational fluid dynamics (CFD). By qualitatively comparing the results at different swirl number, the significant influences of swirl on characteristics of coal gasification such as flow distributions, gas temperature and product composition including hydrogen (H2), carbon monoxide (CO), etc., and on the performance of coal gasification such as averaged exit product composition, carbon conversion rate and cold gas efficiency, were in detail discussed. Especially, a proper swirl number (S ≤ 0.65) in favor of gasification was found for the investigated gasifier in this paper.


1995 ◽  
Vol 117 (4) ◽  
pp. 673-677 ◽  
Author(s):  
C. S. Cook ◽  
J. C. Corman ◽  
D. M. Todd

The integration of gas turbines and combined cycle systems with advances in coal gasification and gas stream cleanup systems will result in economically viable IGCC systems. Optimization of IGCC systems for both emission levels and cost of electricity is critical to achieving this goal. A technical issue is the ability to use a wide range of coal and petroleum-based fuel gases in conventional gas turbine combustor hardware. In order to characterize the acceptability of these syngases for gas turbines, combustion studies were conducted with simulated coal gases using full-scale advanced gas turbine (7F) combustor components. It was found that NOx emissions could be correlated as a simple function of stoichiometric flame temperature for a wide range of heating values while CO emissions were shown to depend primarily on the H2 content of the fuel below heating values of 130 Btu/scf (5125 kJ/NM3) and for H2/CO ratios less than unity. The test program further demonstrated the capability of advanced can-annular combustion systems to burn fuels from air-blown gasifiers with fuel lower heating values as low as 90 Btu/scf (3548 kJ/NM3) at 2300°F (1260°C) firing temperature. In support of ongoing economic studies, numerous IGCC system evaluations have been conducted incorporating a majority of the commercial or near-commercial coal gasification systems coupled with “F” series gas turbine combined cycles. Both oxygen and air-blown configurations have been studied, in some cases with high and low-temperature gas cleaning systems. It has been shown that system studies must start with the characteristics and limitations of the gas turbine if output and operating economics are to be optimized throughout the range of ambient operating temperature and load variation.


2020 ◽  
Vol 9 (1) ◽  
pp. 30-35
Author(s):  
Hendriyana Hendriyana

Rice husk is the waste from agriculture industries that has high potential to produce heat and electricity through the gasification process. Air suction mode is new development for updraft rice husk gasification, where blower are placed at output of gasifier. The objective of this research is to examine these new configuration at several equivalence ratio. The equivalence ratio was varied at 32% and 49% to study temperature profile on gasifier, producer gas volumetric flow rate, composition of producer gas, producer gas heating value, cold gas efficiency and carbon conversion. The time needed to consume rice husk and reach an oxidation temperature of more than 700oC for equivalence ratio of 49% is shorter than 32%. Producer gas rate production per unit weight of rice husk increase from  2.03 Nm3/kg and 2.36 Nm3/kg for equivalence ratio of 32% and 49%, respectively. Composition producer gas for equivalence ratio of 32% is 17.67% CO, 15.39% CO2, 2.87% CH4, 10.62% H2 and 53.45% N2 and 49% is 19.46% CO, 5.94% CO2, 0.90% CH4, 3.46% H2 and 70.24% N2. Producer gas heating value for equivalence ratio 32% and 49% is 4.73 MJ/Nm3 and 3.27 MJ/Nm3, respectively. Cold gas efficiency of the gasifier at equivalence ratio 32% is 69% and at 49% is 55%.


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