A Novel Coal Gasification System Through Thermochemical Regenerative Process of Syngas Sensible Heat to Enhance Cold Gas Efficiency

2017 ◽  
Author(s):  
Dandan Wang ◽  
Sheng Li ◽  
Lin Gao
Keyword(s):  
Energy Level ◽  
Coal Gasification ◽  
The Novel ◽  
Sensible Heat ◽  
Exergy Destruction ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Gasification Technology ◽  
Cold Gas

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.

Novel Coal-Steam Gasification With a Thermochemical Regenerative Process for Power Generation

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Dandan Wang ◽  
Sheng Li ◽  
Lin Gao ◽  
Handong Wu ◽  
Hongguang Jin
Keyword(s):  
Energy Level ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Steam Gasification ◽  
Energy Utilization ◽  
Plant Performance ◽  
The Novel ◽  
Sensible Heat ◽  
Exergy Destruction ◽  
Separation Unit

In this paper, a novel high-efficiency coal gasification technology is proposed in which a regenerative unit is applied to recover syngas sensible heat to generate steam; then, the high-temperature steam is used to gasify coke from a pyrolyzer. Through such a thermochemical regenerative unit, the sensible heat with a lower energy level is upgraded into syngas chemical energy with a higher energy level; therefore, high cold gas efficiency (CGE) is expected from the proposed system. aspenplus software is selected to simulate the novel coal gasification system, and the key parameters are validated by experimentation. Then energy, exergy, and energy-utilization diagram (EUD) analyses are applied to disclose the plant performance enhancement mechanism. It is revealed that 83.2% of syngas sensible heat can be recovered into steam agent with the CGE upgraded to 90%. In addition, with the enhancement of CGE, the efficiency of an integrated gasification combined cycle (IGCC) based on the novel gasification system can be as high as 51.82%, showing a significant improvement compared to 45.2% in the general electric company (GE) gasification-based plant. In the meantime, the irreversible destruction of the gasification procedure is reduced to 25.7% through thermochemical reactions. The increase in the accepted energy level (Aea) and the decreases in the released energy level (Aed) and heat absorption (ΔH) contribute to the reduction in exergy destruction in the gasification process. Additionally, since the oxygen agent is no longer used in the IGCC, 34.5 MW exergy destruction in the air separation unit (ASU) is avoided.

scholarly journals Mathematical modelling of the oxyfuel gasification of pulverized coal fuel

2020 ◽  
Vol 209 ◽  
pp. 03011
Author(s):  
Igor Donskoy
Keyword(s):  
Mathematical Modelling ◽  
Coal Gasification ◽  
Stoichiometric Ratio ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Coal Fuel ◽  
Pulverized Coal Fuel ◽  
Optimal Values ◽  
Gas Efficiency ◽  
Cold Gas

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.

Effect of Swirl on Gasification Characteristics in an Entrained-flow Coal Gasifier

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Rongbin Li ◽  
Mingzhuang Xie ◽  
Hui Jin ◽  
Liejin Guo ◽  
Fengqin Liu
Keyword(s):  
Coal Gasification ◽  
Three Dimensional ◽  
Reaction Model ◽  
Gas Temperature ◽  
Swirl Number ◽  
Entrained Flow ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Product Composition ◽  
Gas Efficiency

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.

scholarly journals Modelling and experimental analysis of a small-scale olive pomace gasifier for cogeneration applications: A techno-economic assessment

2019 ◽  
Vol 25 (4) ◽  
pp. 329-339
Author(s):  
João Cardoso ◽  
Valter Silva ◽  
Daniela Eusébio ◽  
Tiago Carvalho ◽  
Paulo Brito
Keyword(s):  
Economic Assessment ◽  
Gas Production ◽  
Waste To Energy ◽  
Small Scale ◽  
Producer Gas ◽  
Olive Pomace ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Cold Gas

A 2-D numerical simulation approach was implemented to describe the gasification process of olive pomace in a bubbling fluidized bed reactor. The numerical model was validated under experimental gasification runs performed in a 250 kWth quasi-industrial biomass gasifier. The producer gas composition, H2/CO ratio, CH4/H2 ratio, cold gas efficiency and tar content were evaluated. The most suitable applications for the potential use of olive pomace as an energy source in Portugal were assessed based on the results. A techno-economic study and a Monte Carlo sensitivity analysis were performed to assess the feasibility and foresee the main investment risks in conducting olive pomace gasification in small facilities. Results indicated that olive pomace gasification is more suitable for domestic purposes. The low cold gas efficiency of the process (around 20%) turns the process more appropriate for producer gas production in small cogeneration facilities. Olive pomace gasification solutions showed viable economic performance in small cogeneration solutions for agriculture waste-to-energy recovery in olive oil agriculture cooperatives. However, the slender profitability may turn the project unattractive for most investors from a financial standpoint.

scholarly journals Sensitivity Analysis of Different Parameters on the Performance of a CHP Internal Combustion Engine System Fed by a Biomass Waste Gasifier

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 688 ◽  
Author(s):  
Mauro Villarini ◽  
Vera Marcantonio ◽  
Andrea Colantoni ◽  
Enrico Bocci
Keyword(s):  
Internal Combustion Engine ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Waste To Energy ◽  
Biomass Waste ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Cold Gas

The present paper presents a study of biomass waste to energy conversion using gasification and internal combustion engine for power generation. The biomass waste analyzed is the most produced on Italian soil, chosen for suitable properties in the gasification process. Good quality syngas with up to 16.1% CO–4.3% CH4–23.1% H2 can be produced. The syngas lower heating value may vary from 1.86 MJ/ Nm3 to 4.5 MJ/Nm3 in the gasification with air and from 5.2 MJ/ Nm3 to 7.5 MJ/Nm3 in the gasification with steam. The cold gas efficiency may vary from 16% to 41% in the gasification with air and from 37% to 60% in the gasification with steam, depending on the different biomass waste utilized in the process and the different operating conditions. Based on the sensitivity studies carried out in the paper and paying attention to the cold gas efficiency and to the LHV, we have selected the best configuration process for the best syngas composition to feed the internal combustion engine. The influence of syngas fuel properties on the engine is studied through the electrical efficiency and the cogeneration efficiency.

scholarly journals Catalytic Coal Gasification Process Simulation with Alkaline Organic Wastewater in a Fluidized Bed Reactor Using Aspen Plus

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1367 ◽  
Author(s):  
Xiao ◽  
Wang ◽  
Zheng ◽  
Qin ◽  
Zhou
Keyword(s):  
Process Simulation ◽  
Equivalence Ratio ◽  
Coal Gasification ◽  
Aspen Plus ◽  
Operating Conditions ◽  
Catalytic Gasification ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Organic Wastewater

A co-gasification process was proposed both for treating alkaline organic wastewater and to promote coal gasification by the alkaline substances in situ. A catalytic gasification model was developed by introducing a catalytic correction factor to describe the catalytic effects quantitatively. An integrated process simulation was carried out using Aspen Plus equipped with FORTRAN subroutines. The model was verified using the root mean square error between the simulation results and experimental data from the literature. Syngas composition, cold gas efficiency, and carbon conversion efficiency were analyzed with respect to different operating conditions (reaction temperature, steam/coal ratio, and equivalence ratio). The optimal conditions are summarized based on a self-sufficient system by using sensitivity analysis: Gasification temperature of 700 °C, steam/coal ratio = 1.0, and equivalence ratio = 0.4.

A parametric study on coal gasification for the production of syngas

2012 ◽  
Vol 66 (7) ◽  
Author(s):  
Afsin Gungor ◽  
Murat Ozbayoglu ◽  
Cosku Kasnakoglu ◽  
Atilla Biyikoglu ◽  
Bekir Uysal
Keyword(s):  
Parametric Study ◽  
Coal Gasification ◽  
Steam Gasification ◽  
Heating Value ◽  
Fuel Ratio ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Reactor Temperature ◽  
Gas Efficiency ◽  
Optimum Working

AbstractIn this parametric study, the effects of coal and oxidiser type, air-to-fuel ratio, steam-to-fuel ratio, reactor temperature, and pressure on H2 and CO amounts at the gasifier output, H2/CO, and higher heating value of the syngas produced have been calculated using a coal gasification model. Model simulations have been performed to identify the optimum values which are assumed to be 100 % for both cold gas efficiency and carbon conversion efficiency in the gasification process. From this study, it may be observed that the moisture content of the coal type is of crucial importance for the air gasification process; the O2 content of similar coals (taking into consideration the moisture and H2 content) is of significant importance for the air gasification process. When compared with air gasification, air-steam gasification becomes a more effective coal gasification method. The optimum working condition for air-steam gasification is to carry out the process at one atmosphere. High gasifier temperatures are not needed for the air-steam gasification of coal.

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 ◽  
...  
Keyword(s):  
Low Temperature ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Cold Gas Efficiency ◽  
Cycle Systems ◽  
Gas Efficiency ◽  
Cold Gas

Study on Gasification Characteristics of Petroleum Asphalt in a Two-Stage Gasifier

2014 ◽  
Vol 953-954 ◽  
pp. 1673-1677
Author(s):  
Guang Yu Li ◽  
Shi Sen Xu ◽  
Jun Cang Xia ◽  
Yong Qiang Ren
Keyword(s):  
Bituminous Coal ◽  
Heterogeneous Reaction ◽  
Reaction Model ◽  
Utilization Rate ◽  
Two Stage ◽  
Petroleum Asphalt ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Gas Efficiency ◽  
Cold Gas

The gasification performance of petroleum asphalt in a two-stage gasifier was investigated through experiments and simulations. The analysis results of asphalt samples show that the asphalt has characteristics of high volatile content, high calorific value, and low ash content. Coal pyrolysis model, gas-solid heterogeneous reaction model, gas homogeneous reaction model and Gibbs free energy minimization method were employed to build the two-stage entrained flow gasification model and simulate the asphalt gasification process using Aspen Plus software. The results indicate that the cold gas efficiency of asphalt is 3% higher than that of bituminous coal, while the consumption of coal and oxygen is 40% lower than that of bituminous coal. The gasification performance of asphalt is superior to that of coal. In addition, the cold gas efficiency of asphalt can be increased by about 3% when the two-stage gasification process is employed. The utilization rate of coal in the two-stage gasifier is much higher than that in traditional one-stage gasifier.

Simulation of Enriched Air-Steam Biomass Gasification in a Bubbling Fluidized Bed Gasifier

2014 ◽  
Vol 699 ◽  
pp. 510-515
Author(s):  
Miao Miao Niu ◽  
Ya Ji Huang ◽  
Bao Sheng Jin
Keyword(s):  
Fluidized Bed ◽  
Steam Injection ◽  
Biomass Gasification ◽  
Carbon Conversion ◽  
Gasification Process ◽  
Cold Gas Efficiency ◽  
Oxygen Percentage ◽  
Bubbling Fluidized Bed ◽  
Gas Efficiency ◽  
Cold Gas

A model was developed for the enriched air-steam biomass gasification in a bubbling fluidized bed (BFB) gasifier using Aspen Plus. Restricted equilibrium method was used to eliminate the deviation caused by the diffusion effect of gas-particle. The model has been divided into three stages (drying and pyrolysis, partial combustion and gasification) for predicting the gasifier performance. Simulation results for gas composition, carbon conversion and cold gas efficiency versus oxygen percentage and steam to biomass ratio (S/B) were compared with the experimental results. Higher oxygen percentage improves the gasification process, increases the production of H2 and CO and results in better gasification efficiency. With increasing oxygen percentage, the production of CO2 and CH4 show decreasing trends. Steam injection enhances the H2 and CO2 production but decreases CO and CH4 production. Carbon conversion presents a slight decrease trend over the S/B range, while cold gas efficiency is first constant and then decreased.

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