Comparison Between Two-Shaft Simple and Single-Shaft Recuperated Brayton Cycles Using Different Types of Gaseous Fuels

2010 ◽  
Author(s):  
A. K. Malkogianni ◽  
A. Tourlidakis ◽  
A. L. Polyzakis
Keyword(s):  
Natural Gas ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
High Efficiency ◽  
Heating Value ◽  
Gaseous Fuels ◽  
Oil And Natural Gas ◽  
Parametric Studies ◽  
The Impact ◽  
Lower Heating

Geopolitical issues give rise to problems in the smooth and continuous flow of oil and natural gas from the production countries to the consumers’ development countries. In addition, severe environmental issues such as greenhouse gas emissions, eventually guide the consumers to fuels more suitable to the present situation. Alternative fuels such as biogas and coal gas have recently become more attractive because of their benefits, especially for electricity generation. On the other hand, the use of relatively low heating value fuels has a significant effect to the performance parameters of gas turbines. In this paper, the impact of using four fuels with different heating value in the gas turbine performance is simulated. Based on the high efficiency and commercialization criteria, two types of engines are chosen to be simulated: two-shaft simple and single-shaft recuperated cycle gas turbines. The heating values of the four gases investigated, correspond to natural gas and to a series of three gases with gradually lower heating values than that of natural gas. The main conclusions drawn from this design point (DP) and off-design (OD) analysis is that, for a given TET, efficiency increases for both engines when gases with low heating value are used. On the contrary, when power output is kept constant, the use of gases with low heating value will result in a decrease of thermal efficiency. A number of parametric studies are carried out and the effect of operating parameters on performance is assessed. The analysis is performed with customized software, which has been developed for this purpose.

scholarly journals Alternative Fuel Use in Iraq: A way to Reduce Air Pollution

2017 ◽  
Vol 2 (5) ◽  
pp. 20
Author(s):  
Jafaar A. Kadhem ◽  
Khalid Sadiq Reza ◽  
Wahab K. Ahmed
Keyword(s):  
Natural Gas ◽  
Alternative Fuels ◽  
Engine Performance ◽  
Alternative Methods ◽  
Liquefied Petroleum Gas ◽  
Gaseous Fuels ◽  
Lead Compounds ◽  
Power Stations ◽  
Oil And Natural Gas ◽  
Methods Of Operation

The Iraq air is polluted highly by pollutants emitted from automobiles and trucks as well as power stations. This pollution resource is well known it is the burning of oil and natural gas. Iraq has been subjected to a series of wars and economic blockade for more than 40 continuing years. The war and blockade conditions have affected all the country's infrastructure causing huge deterioration in the services provided to Iraqi citizens. The Iraqi refineries as well have been subjected to major destruction and reconstruction several times. Unfortunately, the reconstruction in Iraq conditions was not in appropriate level, and for that reason we find the Iraqi gasoline and diesel are one of the worst fuels in the world. All reports demonstrated that the Iraqi gasoline contains high levels of sulfur (500ppm), as well as high levels of lead compounds to increase octane. The Iraqi diesel contains sulfur up to 1 to 2.5% of its weight which makes it the worst globally.In Iraq there are many alternative fuels that generate better engine performance and emit lower exhaust pollutants while improving fuel consumption. This paper reviews some of the Iraqi experimental work during the past ten years and the available results about using gaseous fuels such as natural gas, liquefied petroleum gas and hydrogen. In addition, the study focus on the use of some additives to gasoline and diesel, such as alcohols and biofuels to reduce the effects of sulfur associated with these types of fuel. The Iraqi research works have found many solutions and alternative methods of operation to eliminate the various engines emitted pollutants. The role has now come to the decision makers to legislate the laws and decisions necessary to switch to new types of alternative fuels.

scholarly journals OIL AND NATURAL GAS TRADE BALANCE AND PRODUCTION EFFECTS IN THE EUROPEAN UNION AND BLACK SEA ECONOMIC COOPERATION COUNTRIES

2017 ◽  
Vol 16 (3 (2017)) ◽  
pp. 261-283
Author(s):  
Evangelos Siskos ◽  
Konstantia Darvidou
Keyword(s):  
European Union ◽  
Natural Gas ◽  
Black Sea ◽  
Trade Balance ◽  
Value Added ◽  
Economic Cooperation ◽  
Close Link ◽  
Oil And Natural Gas ◽  
The Impact ◽  
The Eu

Most European Union and Black Sea Economic Cooperation countries are net importers of petroleum and natural gas. Searching for new deposits and construction of new pipelines can improve energy security in the region. The problem is topical for Greece which has a developed refinery industry and needs to improve its trade balance to repay the accumulated external and public debt. Several new pipeline initiatives through Greece can support relations between the EU and BSEC countries. The paper provides previous research review about energy dependency and the effects of trade, production and transportation of hydrocarbons. Next we provide analysis of the effect of the trade on balance of payments in both the EU and BSeC countries. Import dependency of GDP on oil and natural gas is especially large in Malta, Georgia, Ukraine, Serbia and Latvia. On the other hand Russia and Azerbaijan are large net exporters of hydrocarbons. Then we analyse the impact of mining on labour market and refinery industry development. On average larger value added in mining leads to larger employment at least for males and middle age group of people. But the effect largely varies across countries and time periods. Together with construction of new pipelines growth of extraction can result in dozens of thousands of new jobs in Greece. There is a close link between value added in mining and compensation of employees in that industry. We have found evidence that the clustering effect between mining and manufacture of refined petroleum products and coke exists only in some EU countries.

Impact of Ethane, Propane, and Diluent Content in Natural Gas on the Performance of a Commercial Microturbine Generator

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Richard L. Hack ◽  
Vincent G. McDonell
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Fuel Composition ◽  
Nox Emissions ◽  
Heating Value ◽  
Designed Experiment ◽  
Methane Number ◽  
The Impact ◽  
Lean Conditions

The impact of fuel composition on the performance of power generation devices is gaining interest as the desire to diversify fuel supplies increases. In the present study, measurements of combustion performance were conducted on a commercial natural gas-fired 60kW gas turbine as a function of fuel composition. A statistically designed experiment was carried out and exhaust emissions were obtained for significant amounts of ethane and propane. In addition, a limited study of the effect of inerts was conducted. The results show that emissions of NOx, CO, and NOx∕NO are not well correlated with common descriptions of the fuel, such as higher heating value or methane number. The results and trends indicate that the presence of higher hydrocarbons in the fuel leads to appreciably higher NOx emissions for both test devices operating under similar lean conditions, while having less impact on CO emissions.

scholarly journals EXERGY-BASED INVESTIGATION OF A COAL-FIRED ALLAM CYCLE

2019 ◽  
Vol 137 ◽  
pp. 01018 ◽  
Author(s):  
Jing Luo ◽  
Ogechi Emelogu ◽  
Tatiana Morosuk ◽  
George Tsatsaronis
Keyword(s):  
Fossil Fuels ◽  
Coal Gasification ◽  
High Efficiency ◽  
Cycle Performance ◽  
Energetic Efficiency ◽  
Component Level ◽  
Lower Efficiency ◽  
Heating Value ◽  
Lower Heating Value ◽  
Lower Heating

Allam cycle is a novel cycle that capitalizes on the unique thermodynamic properties of supercritical CO2 and the advantages of oxy-combustion for power generation. It is a high-pressure supercritical carbon dioxide cycle designed to combust fossil fuels such as natural gas or syngas (from coal gasification systems) with complete CO2 separation at a high-efficiency and zero atmospheric emissions. This semi-closed cycle produces sequestration-ready/pipeline quality CO2 by-product, and thus eliminates the need for additional CO2-capture system. The Coal-fueled Allam cycle is targeted to deliver between 51-52% net efficiency (lower heating value) for coal gasification. In this study, the expected energetic efficiency is verified by simulating the system in Ebsilon professional software and the result showed that the net efficiency of the simulated coal-fired plant is 30.7%, which is significantly lower than the targeted value. The lower efficiency maybe as a result of the missing heat integration in the system, the high power demand of the oxidant compressor and CO2 compressors. And an exergy analysis based on published cycle data is employed, to investigate the cycle performance, identify the sources of the cycle’s thermodynamic inefficiencies at the component level; a sensitivity analysis is also performed to study the effects of selected thermodynamic parameters on the overall performance of the coal-fired Allam cycle.

The Ethanol-Water Humidification Process in EvGT Cycles

2004 ◽  
Author(s):  
Marcus Thern ◽  
Torbjo¨rn Lindquist ◽  
Tord Torisson
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Production ◽  
Test Facility ◽  
Level Energy ◽  
Water Mixture ◽  
Evaporation Process ◽  
Heating Value ◽  
Lower Heating Value ◽  
Lower Heating

Ethanol from bio-products has become an important fuel for future power production. However, the present production technology is rather expensive. This paper focuses on how to lower the production cost of ethanol extraction from mash, and to use the ethanol as a primary fuel in gas turbines for heat and power production. Today, ethanol is produced during distillation by supplying energy to extract the ethanol from the mash. Using the evaporation process in the evaporative gas turbine to extract the ethanol from the mash before the distillation step, a lot of energy can be saved. In the evaporation process, the ethanol is extracted directly from the mash using energy from low-level energy sources. The evaporation technology is therefore expected to reduce the cost for the ethanol production. Simultaneous heat and mass transfer inside the ethanol humidification tower drives a mixture of ethanol and water into the compressor discharge air. To investigate the evaporation of a binary mixture into air at elevated pressures and temperatures, a test facility was constructed and integrated into the evaporative gas turbine pilot-plant. The concentration of ethanol in the mash is not constant but depends on the sugar content in the feedstock used in the fermentation process. Tests were therefore conducted at different concentrations of ethanol in the ethanol-water mixture. Tests were also performed at different temperature and flow conditions to establish the influence of these parameters on the lower heating value of the produced low calorific gas. It has been shown that this technology extracts about 80% of the ethanol from the mash. It has also been shown that the composition of the resulting gas depends on the temperatures, flow rates and composition of the incoming streams. The tests have shown that the produced gas has a lower heating value between of 1.8 to 3.8 MJ/kg. The produced gas with heating values in the upper range is possible to use as fuel in the gas turbine without any pilot flame. Initial models of the ethanol humidification process have been established and the initial test results have been used for validating developed models.

scholarly journals Low Ash Fuel and Chemicals From the Convertech Process

1998 ◽  
Author(s):  
Markus M. Benter ◽  
Ian G. Bywater ◽  
Ken E. Scott
Keyword(s):  
Gas Turbines ◽  
Fine Powder ◽  
Environmental Damage ◽  
Processing Plant ◽  
Gaseous Fuels ◽  
Renewable Power ◽  
Biomass Processing ◽  
Renewable Power Generation ◽  
Oil And Natural Gas ◽  
Essential Chemical

A new, efficient process for reducing the ash content, drying and fractionating raw lignocellulosic materials into chemicals and a dry solid end product, eminently suitable as a fuel for conventional boilers or for milling to a fine powder for gas turbine firing, shows strong potential for renewable power generation. The dry, low ash solids, termed “Cellulig™”, will also be suitable for gasification and to drive gas turbines. Sustainable liquid and gaseous fuels will become increasingly necessary in the 21st century to reduce dependence on imported fuels, to replace dwindling supplies of oil and natural gas and to avoid environmental damage from green house gases. Convertech Group Ltd. has built a demonstration biomass processing plant at Burnham, Canterbury, New Zealand, with investment from the energy industry and the Australian Energy Research and Development Council. The essential chemical and process engineering elements are described and the current and future development opportunities outlined.

Alternative Fuels in Gas Turbine Applications: A Simple Method for Assessing the Influence of Fuel on Performances

2000 ◽  
Author(s):  
Michel Molière ◽  
Frédéric Pommel
Keyword(s):  
Gas Turbines ◽  
Alternative Fuels ◽  
Differential Method ◽  
Simple Method ◽  
Gas Condensates ◽  
Exhaust Heat ◽  
Petroleum Distillates ◽  
Output Efficiency ◽  
The Many ◽  
The Impact

Gas turbines have by essence access to a broad range of primary energies. This advantage is essentially exploitable by the Heavy Duty branch which, thanks to moderate compression ratios, robust mechanical designs and versatile combustion systems, can utilise a wide series of commercial and process by-products fuels: natural gas, petroleum distillates, gasified coal or biomass, gas condensates, ash-forming fuels, alcohols etc. In this context, a thorough knowledge of the many-facetted fuel/machine interdependency, which seems insufficiently covered by the existing literature on gas turbines, is of prime interest. This paper is devoted to the thermodynamic aspects of fuel influence. It offers: (i) a review of the main primary energies accessible to stationary gas turbines, (ii) a new, differential method for assessing the impact of fuel on machine thermodynamics, with original equations accounting for the changes in power output, efficiency and exhaust heat.

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