Structured Catalysts for Environmental and Energetical Applications

2006 ◽  
Vol 45 ◽  
pp. 2188-2197 ◽  
Author(s):  
Pio Forzatti ◽  
Fabrizio Arosio ◽  
Cinzia Cristiani
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Present Status ◽  
Gas Turbines ◽  
Catalytic Combustion ◽  
Industrial Effluents ◽  
Soot Combustion ◽  
Exhaust Gases ◽  
Structured Catalysts ◽  
Stationary Sources

The paper presents an overview of the present status and the perspectives for use of structured catalysts in the power generation, transport and environmental sectors. In particular catalytic combustion of natural gas for the production of energy in gas turbines, abatement of NOx from mobile and stationary sources under lean and stoichiometric conditions, removal of VOC from industrial effluents and soot combustion in the exhaust gases of vehicles are discussed.

Predicting Flameholding for Hydrogen and Natural Gas Flames at Gas Turbine Premixer Conditions

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Elliot Sullivan-Lewis ◽  
Vincent McDonell
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Experimental Studies ◽  
Temperature Variations ◽  
Auto Ignition ◽  
Chamber Temperature ◽  
Transient Events ◽  
Significant Effort

Lean-premixed gas turbines are now common devices for low emissions stationary power generation. By creating a homogeneous mixture of fuel and air upstream of the combustion chamber, temperature variations are reduced within the combustor, which reduces emissions of nitrogen oxides. However, by premixing fuel and air, a potentially flammable mixture is established in a part of the engine not designed to contain a flame. If the flame propagates upstream from the combustor (flashback), significant engine damage can result. While significant effort has been put into developing flashback resistant combustors, these combustors are only capable of preventing flashback during steady operation of the engine. Transient events (e.g., auto-ignition within the premixer and pressure spikes during ignition) can trigger flashback that cannot be prevented with even the best combustor design. In these cases, preventing engine damage requires designing premixers that will not allow a flame to be sustained. Experimental studies were conducted to determine under what conditions premixed flames of hydrogen and natural gas can be anchored in a simulated gas turbine premixer. Tests have been conducted at pressures up to 9 atm, temperatures up to 750 K, and freestream velocities between 20 and 100 m/s. Flames were anchored in the wakes of features typical of premixer passageways, including cylinders, steps, and airfoils. The results of this study have been used to develop an engineering tool that predicts under what conditions a flame will anchor, and can be used for development of flame anchoring resistant gas turbine premixers.

Fast Pyrolysis Oil for Power Generation

2006 ◽  
Author(s):  
David Chiaramonti ◽  
Anja Oasmaa ◽  
Yrjo¨ Solantausta
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbines ◽  
Large Scale ◽  
Fast Pyrolysis ◽  
High Energy ◽  
High Energy Density ◽  
Current Status ◽  
Pyrolysis Oil

Biomass fast-pyrolysis oil (PO) is a liquid biofuel derived from lignocellulosic biomass: it offers several advantages compared to the direct us of solid bio fuels, such as high energy density, storability and transportability typical of liquid fuels, possibility to use the fuel in engines and turbines, easier downscaling of plants (which is a very important aspect for decentralized energy generation schemes). In addition, PO is the lowest cost biofuel, thus offering the possibility to penetrate also the large scale power generation market. Biomass POs have been studied and applications tested for many years, either for heat generation in medium-scale boilers or power generation. The present works reviews and analyses the most relevant experiences carried out so far and published results in power production from biomass PO. Power generation systems (PGS) which are here examined are gas turbines, diesel engines, stirling engines, as well as co-firing applications in large scale power plants (coal or natural gas plants). The main techniques for upgrading this biofuel and their impact on technologies are also shortly introduced and considered. The current status of development for each PO-based power generation option is discussed. This review work showed that long term demonstration (either technical or economical) is however still needed, even for the most developed technologies (use of PO in modified gas turbines and cofiring in natural gas stations): projects are on going to achieve long term demonstration.

scholarly journals Feasibility study on HYSOL CSP

2016 ◽  
Vol 13 (1) ◽  
Keyword(s):  
Power Generation ◽  
High Temperature ◽  
Natural Gas ◽  
Economic Analysis ◽  
Molten Salt ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Economic Feasibility ◽  
Solar Irradiation ◽  
Firm Power

Concentrating Solar Power (CSP) plants utilize thermal conversion of direct solar irradiation. A trough or tower configuration focuses solar radiation and heats up oil or molten salt that subsequently in high temperature heat exchangers generate steam for power generation. High temperature molten salt can be stored and the stored heat can thus increase the load factor and the usability for a CSP plant, e.g. to cover evening peak demand. In the HYSOL concept (HYbrid SOLar) such configuration is extended further to include a gas turbine fuelled by upgraded biogas or natural gas. The optimised integrated HYSOL concept, therefore, becomes a fully dispatchable (offering firm power) and fully renewable energy source (RES) based power supply alternative, offering CO2-free electricity in regions with sufficient solar resources. The economic feasibility of HYSOL configurations is addressed in this paper. The analysis is performed from a socio- and private- economic perspective. In the socio-economic analysis, the CO2 free HYSOL alternative is discussed relative to conventional reference firm power generation technologies. In particular the HYSOL performance relative to new power plants based on natural gas (NG) such as open cycle or combined cycle gas turbines (OCGT or CCGT) are in focus. In the corporate-economic analysis the focus is on the uncertain technical and economic parameters. The core of the analyses is based on the LCOE economic indicator. In the corporate economic analysis, NPV and IRR are furthermore used to assess the feasibility. The feasibility of renewable based HYSOL power plant configurations attuned to specific electricity consumption patterns in selected regions with promising solar energy potentials are discussed.

Economic and Technical Challenges Facing Large-Scale Gas Turbine Projects due to Environmental Requirements for Extremely Low Emissions

2001 ◽  
Author(s):  
Justin Zachary
Keyword(s):  
United States ◽  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Large Scale ◽  
The United States ◽  
Fuel Gas ◽  
Environmental Requirements ◽  
Low Sulfur

Since 1998, the United States has experienced a tremendous increase in power generation projects using gas turbine technology. By burning natural gas as the primary fuel and low sulfur oil as a back-up fuel, gas turbines are the cleanest form of fossil power generation.

Enhanced Fuel Flexibility and Emissions Compliance for Gas Turbines Through Model Based Controls Technology

2013 ◽  
Author(s):  
Ranjith Malapaty ◽  
Suresh M. V. J. J.
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbines ◽  
Power Plants ◽  
Power Demand ◽  
Combustion Dynamics ◽  
Fuel Flexibility ◽  
Plant Operations ◽  
Lng Fuel ◽  
Alternate Fuels

The world is facing complex and mounting environmental challenges. Increased fuel costs and increased market capacity in power generation markets is driving a transformation in power plant operations. Power plants are seeking ways to maximize revenue potential during peak conditions and minimize operational costs during off-peak conditions. Although proven natural gas reserves have increased globally by nearly 50% over the last 20 years, much of this growth has been focused in select regions and countries. In parallel to the discovery of new reserves is the increase in power demand across the globe. However, there are many regions of the globe in which power demand is not being matched by increased local supplies of natural gas, or in infrastructure required to supply natural gas to power generation assets. Given these drivers, there is growing global interest in LNG & alternate fuels. This phenomenon is driving a trend to explore the potential of using LNG fuels which can be easily transported across the globe as an alternative for power generation. In a carbon-constrained environment, the technology trend is for combustion systems capable of burning LNG fuel in combination with delivering the required operability. This paper will focus on developments in GE’s heavy duty gas turbines that enable operation on fuels with varying properties, providing fuel flexibility for sustainable power generation and better emissions compliance. GE’s turbine control system employs physics-based models of gas turbine operability boundaries (e.g., emissions, combustion dynamics, etc.), to continuously estimate current boundary levels and make adjustments as required.

Low Emissions, Renewable, Dispatchable Power Generation Using Ethanol/Natural Gas Blends

2014 ◽  
Author(s):  
Maclain M. Holton ◽  
Michael S. Klassen ◽  
Leo D. Eskin ◽  
Richard J. Joklik ◽  
Richard J. Roby
Keyword(s):  
Power Generation ◽  
Heat Exchanger ◽  
Natural Gas ◽  
Power Output ◽  
Gas Turbines ◽  
Waste Heat ◽  
Full Range ◽  
Liquid Fuels ◽  
Power Sources ◽  
Pollution Levels

Nearly all states now have renewable portfolio standards (RPS) requiring electricity suppliers to produce a certain fraction of their electricity using renewable sources. Many renewable energy technologies have been developed to contribute to RPS requirements, but these technologies lack the advantage of being a dispatchable source which would give a grid operator the ability to quickly augment power output on demand. Gas turbines burning biofuels can meet the need of being dispatchable while using renewable fuels. However, traditional combustion of liquid fuels would not meet the pollution levels of modern dry, low emission (DLE) gas turbines burning natural gas without extensive back-end clean-up. A Lean, Premixed, Prevaporized (LPP) combustion technology has been developed to vaporize liquid ethanol and blend it with natural gas creating a mixture which can be burned in practically any combustion device in place of ordinary natural gas. The LPP technology delivers a clean-burning gas which is able to fuel a gas turbine engine with no alterations made to the combustor hardware. Further, the fraction of ethanol blended in the LPP gas can be quickly modulated to maintain the supplier’s overall renewable quotient to balance fluctuations in power output of less reliable renewable power sources such as wind and solar. The LPP technology has successfully demonstrated over 1,000 hours of dispatchable power generation on a 30 kW Capstone C30 microturbine using vaporized liquid fuels. The full range of fuel mixtures ranging from 100% methane with no ethanol addition to 100% ethanol with no methane addition have been burned in the demonstration engine. Emissions from ethanol/natural gas mixtures have been comparable to baseline natural gas emissions of 3 ppm NOx and 30 ppm CO. Waste heat from the combustor exhaust is recovered in an indirect heat exchanger and is used to vaporize the ethanol as it is blended with natural gas. This design allows for startup on natural gas and blending of vaporized ethanol once the heat exchanger has reached its operating temperature.

Flexible Natural Gas/Intermittent Renewable Hybrid Power Plants

2017 ◽  
Author(s):  
Michael Welch ◽  
Andrew Pym
Keyword(s):  
Power Generation ◽  
Energy Storage ◽  
Power Plant ◽  
Natural Gas ◽  
Gas Turbines ◽  
Fossil Fuel ◽  
Power Transmission ◽  
Hybrid Power ◽  
Renewable Power ◽  
Storage Technologies

Increasing grid penetration of intermittent renewable power from wind and solar is creating challenges for the power industry. There are times when generation from these intermittent sources needs to be constrained due to power transmission capacity limits, and times when fossil fuel power plant are required to rapidly compensate for large power fluctuations, for example clouds pass over a solar field or the wind stops blowing. There have been many proposals, and some actual projects, to store surplus power from intermittent renewable power in some form or other for later use: Batteries, Compressed Air Energy Storage (CAES), Liquid Air Energy Storage (LAES), heat storage and Hydrogen being the main alternatives considered. These technologies will allow power generation during low periods of wind and solar power, using separate discrete power generation plant with specifically designed generator sets. But these systems are time-limited so at some point, if intermittent renewable power generation does not return to its previous high levels, fossil fuel power generation, usually from a large centralized power plant, will be required to ensure security of supplies. The overall complexity of such a solution to ensure secure power supplies leads to high capital costs, power transmission issues and potentially increased carbon emissions to atmosphere from the need to keep fossil fuel plant operating at low loads to ensure rapid response. One possible solution is to combine intermittent renewables and energy storage technologies with fast responding, flexible natural gas-fired gas turbines to create a reliable, secure, low carbon, decentralized power plant. This paper considers some hybrid power plant designs that could combine storage technologies and gas turbines in a single location to maximize clean energy production and reduce CO2 emissions while still providing secure supplies, but with the flexibility that today’s grid operators require.

Evaluation of Arabian Super Light Crude Oil for Use in a F-Class DLN Combustion System

2014 ◽  
Author(s):  
Jeffrey Goldmeer ◽  
Richard Symonds ◽  
Paul Glaser ◽  
Bassam Mohammad ◽  
Zac Nagel ◽  
...  
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Crude Oil ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Oil Prices ◽  
Combustion System ◽  
Heavy Duty ◽  
Global Trends ◽  
Heavy Liquids

Global trends in natural gas and distillate oil prices and availability continue to influence decisions on power generation fuel choice. In some regions, heavy liquids are being selected as gas turbine fuels. One particular crude oil, Arabian Super Light (ASL), has the potential to be used as a primary or back-up fuel in F-class heavy duty gas turbines. This paper presents the results of a set of tests performed on ASL to determine the potential of using it in a Dry Low NOx (DLN) combustion system for operation in an F-class gas turbine.

Past, Present and Future of Combined Cycle Power Plants: From an A/E’s Perspective

2001 ◽  
Author(s):  
Anup Singh
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Rapid Growth ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Electrical Transmission ◽  
Capital Costs ◽  
The U.S

In the 1970s, power generation from gas turbines was minimal. Gas turbines in those days were run on fuel oil, since there was a so-called “natural gas shortage”. The U.S. Fuel Use Act of 1978 essentially disallowed the use of natural gas for power generation. Hence there was no incentive on the part of gas turbine manufacturers to invest in the development of gas turbine technology. There were many regulatory developments in the 1980s and 1990s, which led to the rapid growth in power generation from gas turbines. These developments included Public Utility Regulatory Policy Act of 1978 (encouraging cogeneration), FERC Order 636 (deregulating natural gas industry), Energy Policy Act of 1992 (creating EWGs and IPPs) and FERC Order 888 (open access to electrical transmission system). There was also a backlash from excessive electric rates due to high capital recovery of nuclear and coal-fired plant costs caused by tremendous cost increase resulting from tightening NRC requirements for nuclear plants and significant SO2/NOx/other emissions controls required for coal-fired plants. During this period, rapid technology developments took place in the metallurgy, design, efficiency, and reliability of gas turbines. In addition, U.S. DOE contributed to these developments by encouraging research and development efforts in high temperature and high efficiency gas turbines. Today we are seeing a tremendous explosion of power generating facilities by electric utilities and Independent Power Producers (IPPs). A few years ago, Merchant Power (generation without power purchase agreements) was unheard of. Today it is growing at a very fast pace. Can this rapid growth be sustained? The paper will explore the factors that will play a significant role in the future growth of gas turbine-based power generation in the U.S. The paper will also discuss the methods and developments that could decrease the capital costs of gas turbine power plants resulting in the lowest cost generation compared to other power generation technologies.

Model-Based Thermodynamic Analysis of a Hydrogen-Fired Gas Turbine with External Exhaust Gas Recirculation

2021 ◽  
Author(s):  
Thomas Bexten ◽  
Sophia Jörg ◽  
Nils Petersen ◽  
Manfred Wirsum ◽  
Pei Liu ◽  
...  
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Carbon Capture ◽  
Exhaust Gas ◽  
Model Based ◽  
Renewable Power ◽  
Renewable Power Generation

Abstract Climate science shows that the limitation of global warming requires a rapid transition towards net-zero emissions of greenhouse gases (GHG) on a global scale. Expanding renewable power generation is seen as an imperative measure within this transition. To compensate for the inherent volatility of renewable power generation, flexible and dispatchable power generation technologies such as gas turbines are required. If operated with CO2-neutral hydrogen or in combination with carbon capture plants, a GHG-neutral gas turbine operation could be achieved. An effective leverage to enhance carbon capture efficiency and a possible measure to safely burn hydrogen in gas turbines is the partial external recirculation of exhaust gas. By means of a model-based analysis of a gas turbine, the present study initially assesses the thermodynamic impact caused by a fuel switch from natural gas to hydrogen. Although positive trends such as increasing net electrical power output and thermal efficiency can be observed, the overall effect on the gas turbine process is only minor. In a following step, the partial external recirculation of exhaust gas is evaluated and compared both for the combustion of natural gas and hydrogen, regardless of potential combustor design challenges. The influence of altering working fluid properties throughout the whole gas turbine process is thermodynamically evaluated for ambient temperature recirculation and recirculation at an elevated temperature. A reduction in thermal efficiency can be observed as well as non-negligible changes of relevant process variables. These changes are more distinctive at a higher recirculation temperature

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