Sustainable Retrofit Design of Natural Gas Power Plants for Low-Grade Energy Recovery

2019 ◽  
Vol 58 (42) ◽  
pp. 19571-19585
Author(s):  
Qiao Q. Tang ◽  
Chang He ◽  
Qing L. Chen ◽  
Bing J. Zhang
Keyword(s):  
Natural Gas ◽  
Energy Recovery ◽  
Power Plants ◽  
Low Grade ◽  
Retrofit Design

Evaluation of the washability characteristics of Khushab coal (Pakistani) by heavy media separation process

2017 ◽  
Vol 28 (5-6) ◽  
pp. 598-607 ◽  
Author(s):  
Hafiz Sana ◽  
Sumaira Kanwal ◽  
Javaid Akhtar ◽  
Naseer Sheikh ◽  
Shahid Munir
Keyword(s):  
Energy Recovery ◽  
Power Plants ◽  
Calorific Value ◽  
Environmental Issues ◽  
Thermochemical Conversion ◽  
Low Grade ◽  
Particle Sizes ◽  
Clean Coal ◽  
Recovery Schemes ◽  
Combustion Technique

The use of high-sulfur Pakistani coals can cause serious problems of slagging and fouling in thermochemical conversion reactors along with environmental issues like acid rain, etc. In this study, a pre-combustion technique, namely heavy media separation, is employed for the cleaning of low-grade Pakistani coal. Six crushed coal samples of different particle sizes were individually subjected to heavy media solutions of ZnCl2 of different specific gravities. It was found that the sample with a particle size of −6.25+4 mm at specific gravity of 1.4 produced the optimum float product as clean coal, showing 83.53% yield of clean coal with 1.24% ash and 1.0% sulfur contents. An overall reduction of 91.68% in ash and 86.11% sulfur contents was obtained. Moreover, up to 19.3% enhancement of gross calorific value was achieved. The resultant clean coal can be used in various energy recovery schemes in Pakistan such as coal-fired power plants and cement industries.

Hybrid Dual-Fuel Combined Cycles: General Performance Analysis

2002 ◽  
Author(s):  
Miroslav P. Petrov ◽  
Andrew R. Martin ◽  
Laszlo Hunyadi
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Small Scale ◽  
Dual Fuel ◽  
Low Grade ◽  
Steam Boiler ◽  
Electrical Efficiency ◽  
Combined Cycles ◽  
Gas Fuel ◽  
The Impact

The hybrid dual-fuel combined cycle concept is a promising technology for increasing the energy utilization of low-grade (solid) fuels. Advantages such as enhanced electrical efficiency, favorable economics, and relative ease of construction and operation have been pointed out by various authors in previous studies. The present investigation aims to assess the performance of natural gas and coal- or biomass-fired hybrid combined cycles, with a gas turbine as topping cycle and a steam boiler as bottoming cycle. A parametric analysis considers the impact of the natural gas/solid fuel energy ratio on the electrical efficiency of various hybrid system configurations. Results show that significant performance improvements (in the order of several percentage points in electrical efficiency) can be achieved by these hybrid configurations when compared to the reference (two independent, single-fuel power plants at the given scales). In large-scale power plants with coal-fired bottoming cycle, efficiencies continuously rise as the share of natural gas fuel is increased up to the cycle integration limits, while an optimum can be seen for the small-scale biomass-fired bottoming cycles (with modest steam parameters) at a certain share of natural gas fuel input.

Optimization study of large-scale low-grade energy recovery from conventional Rankine cycle power plants

2009 ◽  
Vol 34 (12) ◽  
pp. 1071-1087 ◽  
Author(s):  
K. M. Mohamed ◽  
M. C. Bettle ◽  
A. G. Gerber ◽  
J. W. Hall
Keyword(s):  
Energy Recovery ◽  
Power Plants ◽  
Large Scale ◽  
Rankine Cycle ◽  
Low Grade ◽  
Optimization Study

Effect of Chemical Hythane Composition on Pressure in Combustion Chamber of Engine

2019 ◽  
pp. 36-42
Author(s):  
A. P. Shaikin ◽  
I. R. Galiev
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Power Plants ◽  
Engine Speed ◽  
Combustion Engine ◽  
Fuel Mixture ◽  
Maximum Pressure ◽  
Chamber Volume ◽  
Excess Air ◽  
Scientific Papers

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.

Current and Future Technologies for Natural Gas Combined Cycle (NGCC) Power Plants

2013 ◽  
Author(s):  
Norma J. Kuehn ◽  
Kajal Mukherjee ◽  
Paul Phiambolis ◽  
Lora L. Pinkerton ◽  
Elsy Varghese ◽  
...  
Keyword(s):  
Natural Gas ◽  
Power Plants ◽  
Combined Cycle ◽  
Natural Gas Combined Cycle ◽  
Future Technologies

Energy and Exergy Analyses of a Power Plant With Carbon Dioxide Capture Using Multistage Chemical Looping Combustion

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Bilal Hassan ◽  
Oghare Victor Ogidiama ◽  
Mohammed N. Khan ◽  
Tariq Shamim
Keyword(s):  
Carbon Dioxide ◽  
Power Plant ◽  
Natural Gas ◽  
Co2 Capture ◽  
Power Plants ◽  
Waste Heat ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Operating Pressure ◽  
Efficiency Gain

A thermodynamic model and parametric analysis of a natural gas-fired power plant with carbon dioxide (CO2) capture using multistage chemical looping combustion (CLC) are presented. CLC is an innovative concept and an attractive option to capture CO2 with a significantly lower energy penalty than other carbon-capture technologies. The principal idea behind CLC is to split the combustion process into two separate steps (redox reactions) carried out in two separate reactors: an oxidation reaction and a reduction reaction, by introducing a suitable metal oxide which acts as an oxygen carrier (OC) that circulates between the two reactors. In this study, an Aspen Plus model was developed by employing the conservation of mass and energy for all components of the CLC system. In the analysis, equilibrium-based thermodynamic reactions with no OC deactivation were considered. The model was employed to investigate the effect of various key operating parameters such as air, fuel, and OC mass flow rates, operating pressure, and waste heat recovery on the performance of a natural gas-fired power plant with multistage CLC. The results of these parameters on the plant's thermal and exergetic efficiencies are presented. Based on the lower heating value, the analysis shows a thermal efficiency gain of more than 6 percentage points for CLC-integrated natural gas power plants compared to similar power plants with pre- or post-combustion CO2 capture technologies.

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.

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