Development and Experimental Investigation of a Tubular Combustor for Pyrolysis Oil Burning

Author(s):  
Martin Beran ◽  
Lars-Uno Axelsson

The growing demand for more economical and environmentally friendly power generation forces the industry to search for fuels that can replace the conventional fossil fuels. This has led to significant developments in the production of alternative fuels during the last years, which have made them a reliable and relatively efficient source of energy. One example of these alternative fuels is the pyrolysis oil. However, higher viscosity, lower heat content, limited chemical stability, and its ability to create sediment make pyrolysis oil challenging for gas turbines. The OPRA OP16 gas turbine is an all radial single-shaft gas turbine rated at 1.9 MW. The all radial design, together with the lack of intricate cooling geometries in the hot section, makes this gas turbine suitable for operation on these fuels. This paper presents an experimental investigation of pyrolysis oil combustion in a tubular combustor developed, especially for low-calorific fuels. The experiments have been performed in an atmospheric combustion test rig, and the results have been compared to the results obtained from ethanol and diesel combustion. It was found that it was possible to burn pure pyrolysis oil in the load range between 70% and 100% with a combustion efficiency exceeding 99% and without creation of sediments on the combustor inner wall. It was found that the NOx emissions were similar for pyrolysis oil and diesel, whereas the CO emissions were twice as high for pyrolysis oil. A comparison between the air blast nozzle and the pressure nozzle was performed. The air blast nozzle was found to be more suitable due to its better performance over a wider operating range and that it is more resistant to erosion and abrasion. It was found that the maximum allowed droplet size of the pyrolysis oil spray should be about 50–70% of the droplet size for diesel fuel.

Author(s):  
Martin Beran ◽  
Lars-Uno Axelsson

The growing demand for more economical and environmentally friendly power generation forces the industry to search for fuels that can replace the conventional fossil fuels. This has led to significant developments in the production of alternative fuels during the last years, which have made them a reliable and relatively efficient source of energy. One example of these alternative fuels is the pyrolysis oil. However, higher viscosity, lower heat content, limited chemical stability and its ability to create sediment make pyrolysis oil challenging for gas turbines. The OPRA OP16 gas turbine is an all radial single-shaft gas turbine rated at 1.9 MW. The all radial design, together with the lack of intricate cooling geometries in the hot section, makes this gas turbine suitable for operation on these fuels. This paper presents an experimental investigation of pyrolysis oil combustion in a tubular combustor developed especially for low-calorific fuels. The experiments have been performed in an atmospheric combustion test rig and the results have been compared to the results obtained from ethanol and diesel combustion. It was found that it was possible to burn pure pyrolysis oil in the load range between 70 to 100% with a combustion efficiency exceeding 99% and without creation of sediments on the combustor inner wall. It was found that the NOx emissions were similar for pyrolysis oil and diesel, whereas the CO emissions were twice as high for pyrolysis oil. A comparison between the air blast nozzle and the pressure nozzle was performed. The air blast nozzle was found to be more suitable due to its better performance over a wider operating range and that it is more resistant to erosion and abrasion. It was found that the maximum allowed droplet size of the pyrolysis oil spray should be about 50–70% of the droplet size for diesel fuel.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2156 ◽  
Author(s):  
Oleksandr Cherednichenko ◽  
Valerii Havrysh ◽  
Vyacheslav Shebanin ◽  
Antonina Kalinichenko ◽  
Grzegorz Mentel ◽  
...  

Growing economies need green and renewable energy. Their financial development can reduce energy consumption (through energy-efficient technologies) and replace fossil fuels with renewable ones. Gas turbine engines are widely used in transport and industry. To improve their economic attractiveness and to reduce harmful emissions, including greenhouse gases, alternative fuels and waste heat recovery technologies can be used. A promising direction is the use of alcohol and thermo-chemical recuperation. The purpose of this study is to estimate the economic efficiency and carbon dioxide emissions of an alcohol-fueled regenerative gas turbine engine with thermo-chemical recuperation. The carbon dioxide emissions have been determined using engine efficiency, fuel properties, as well as life cycle analysis. The engine efficiency was maximized by varying the water/alcohol ratio. To evaluate steam fuel reforming for a certain engine, a conversion performance factor has been suggested. At the optimal water/methanol ratio of 3.075 this technology can increase efficiency by 4% and reduce tank-to-wake emission by 80%. In the last 6 months of 2019, methanol prices were promising for power and cogeneration plants in remote locations. The policy recommendation is that local authorities should pay attention to alcohol fuel and advanced turbines to curb the adverse effects of burning petroleum fuel on economic growth and the environment.


2021 ◽  
Author(s):  
Thijs Bouten ◽  
Jan Withag ◽  
Lars-Uno Axelsson ◽  
Joris Koomen ◽  
Diethard Jansen ◽  
...  

Abstract Gas turbines with a combustion system for hydrogen operation offer a low carbon solution to support the stability of the energy grid. This provides a solution capturing the needs for energy storage, in the form of hydrogen, and flexible power generation. Fuel flexibility is a key requirement to reduce the operational risks in case hydrogen is not available, whereby hydrogen can be combined with other conventional or alternative fuels. A key issue to achieve 100% hydrogen combustion with low emissions is to prevent flashback. To address the challenges, a project consortium was set-up consisting of gas turbine equipment manufacturers, academia and end-users. The major objective is to develop a cost-effective, ultra-low emissions (sub 9 ppm NOx and CO) combustion system for gas turbines in the 1–300 MW output range, including the 1.85 MWe OPRA OP16 gas turbine. At the center of this innovative high-technology project is the patented and novel aerodynamic trapped vortex FlameSheet™ combustion technology platform. Burner concepts based on an aerodynamically trapped vortex flame stabilization have a higher resistance towards flame blowout than conventional swirl stabilized burners. This paper will present the results of the first phase of the project, whereby atmospheric testing of the upgraded FlameSheet™ combustor has been performed operating on natural gas, hydrogen and mixtures thereof. The optimized combustor configurations demonstrated a wide load range on 100% hydrogen, and these results will be presented.


2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110209
Author(s):  
Zain Ul Hassan ◽  
Muhammad Usman ◽  
Muhammad Asim ◽  
Ali Hussain Kazim ◽  
Muhammad Farooq ◽  
...  

Despite a number of efforts to evaluate the utility of water-diesel emulsions (WED) in CI engine to improve its performance and reduce its emissions in search of alternative fuels to combat the higher prices and depleting resources of fossil fuels, no consistent results are available. Additionally, the noise emissions in the case of WED are not thoroughly discussed which motivated this research to analyze the performance and emission characteristics of WED. Brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) were calculated at 1600 rpm within 15%–75% of the load range. Similarly, the contents of NOx, CO, and HC, and level of noise and smoke were measured varying the percentage of water from 2% to 10% gradually for all values of loads. BTE in the case of water emulsified diesel was decreased gradually as the percentage of water increased accompanied by a gradual increase in BSFC. Thus, WED10 showed a maximum 13.08% lower value of BTE while BSFC was increased by 32.28%. However, NOx emissions (21.8%) and smoke (48%) were also reduced significantly in the case of WED10 along with an increase in the emissions of HC and CO and noise. The comparative analysis showed that the emulsified diesel can significantly reduce the emission of NOx and smoke, but it has a negative impact on the performance characteristics and HC, CO, and noise emissions which can be mitigated by trying more fuels variations such as biodiesel and using different water injection methods to decrease dependency on fossil fuels and improve the environmental impacts of CI engines.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vedant Dwivedi ◽  
Srikanth Hari ◽  
S. M. Kumaran ◽  
B. V. S. S. S. Prasad ◽  
Vasudevan Raghavan

Abstract Experimental and numerical study of flame and emission characteristics in a tubular micro gas turbine combustor is reported. Micro gas turbines are used for distributed power (DP) generation using alternative fuels in rural areas. The combustion and emission characteristics from the combustor have to be studied for proper design using different fuel types. In this study methane, representing fossil natural gas, and biogas, a renewable fuel that is a mixture of methane and carbon-dioxide, are used. Primary air flow (with swirl component) and secondary aeration have been varied. Experiments have been conducted to measure the exit temperatures. Turbulent reactive flow model is used to simulate the methane and biogas flames. Numerical results are validated against the experimental data. Parametric studies to reveal the effects of primary flow, secondary flow and swirl have been conducted and results are systematically presented. An analysis of nitric-oxides emission for different fuels and operating conditions has been presented subsequently.


Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
João Roberto Barbosa ◽  
Rob Johan Maria Bastiaans ◽  
Philip de Goey

Currently, high efficiency and low emissions are most important requisites for the design of modern gas turbines due to the strong environmental restrictions around the world. In the past years, alternative fuels have been considered for application in industrial gas turbines. Therefore, combustor performance, pollutant emissions and the ability to burn several fuels became of much concern and high priority has been given to the combustor design. This paper describes a methodology focused on the design of stationary gas turbines combustion chambers with the ability to efficiently burn conventional and alternative fuels. A simplified methodology is used for the calculations of the equilibrium temperature and chemical species in the primary zone of a gas turbine combustor. Direct fuel injection and diffusion flames, together with numerical methods like Newton-Raphson, LU Factorization and Lagrange Polynomials, are used for the calculations. Diesel, ethanol and methanol fuels were chosen for the numerical study. A computer code sequentially calculates the main geometry of the combustor. From the numerical simulation it is concluded that the basic gas turbine combustor geometry, for some operating conditions and burning diesel, ethanol or methanol, are of similar sizes, because the development of aerodynamic characteristics predominate over the thermochemical properties. It is worth to note that the type of fuel has a marked effect on the stability and combustion advancement in the combustor. This can be seen when the primary zone is analyzed under a steady-state operating condition. At full power, the pressure is 1.8 MPa and the temperature 1,000 K at the combustor inlet. Then, the equivalence ratios in the primary zone are 1.3933 (diesel), 1.4352 (ethanol) and 1.3977 (methanol) and the equilibrium temperatures for the same operating conditions are 2,809 K (diesel), 2,754 K (ethanol) and 2,702 K (methanol). This means that the combustor can reach similar flame stability conditions, whereas the combustion efficiency will require richer fuel/air mixtures of ethanol or methanol are burnt instead of diesel. Another important result from the numerical study is that the concentration of the main pollutants (CO, CO2, NO, NO2) is reduced when ethanol or methanol are burnt, in place of diesel.


Author(s):  
Pierre A. Glaude ◽  
Rene´ Fournet ◽  
Roda Bounaceur ◽  
Michel Molie`re

Many investigations are currently carried out in order to reduce CO2 emissions in power generation. Among alternative fuels to natural gas and gasoil in gas turbine applications, dimethyl ether (DME; formula: CH3-O-CH3) represents a possible candidate in the next years. This chemical compound can be produced from natural gas or coal/biomass gasification. DME is a good substitute for gasoil in diesel engine. Its Lower Heating Value is close to that of ethanol but it offers some advantages compared to alcohols in terms of stability and miscibility with hydrocarbons. While numerous studies have been devoted to the combustion of DME in diesel engines, results are scarce as far as boilers and gas turbines are concerned. Some safety aspects must be addressed before feeding a combustion device with DME because of its low flash point (as low as −83°C), its low auto-ignition temperature and large domain of explosivity in air. As far as emissions are concerned, the existing literature shows that in non premixed flames, DME produces less NOx than ethane taken as parent molecular structure, based on an equivalent heat input to the burner. During a field test performed in a gas turbine, a change-over from methane to DME led to a higher fuel nozzle temperature but to a lower exhaust gas temperature. NOx emissions decreased over the whole range of heat input studied but a dramatic increase of CO emissions was observed. This work aims to study the combustion behavior of DME in gas turbine conditions with the help of a detailed kinetic modeling. Several important combustion parameters, such as the auto-ignition temperature (AIT), ignition delay times, laminar burning velocities of premixed flames, adiabatic flame temperatures, and the formation of pollutants like CO and NOx have been investigated. These data have been compared with those calculated in the case of methane combustion. The model was built starting from a well validated mechanism taken from the literature and already used to predict the behavior of other alternative fuels. In flame conditions, DME forms formaldehyde as the major intermediate, the consumption of which leads in few steps to CO then CO2. The lower amount of CH2 radicals in comparison with methane flames seems to decrease the possibility of prompt-NO formation. This paper covers the low temperature oxidation chemistry of DME which is necessary to properly predict ignition temperatures and auto-ignition delay times that are important parameters for safety.


Author(s):  
Hans Juergen Kiesow ◽  
Gerard McQuiggan

The object of this paper will be to examine the market place and some of the consequential technical challenges facing large frame utility gas turbines (greater than 100MW’s) over the next decade. The significant and rapid increase in the price of oil and gas and restrictions in fuel and electricity supply are posing many obstacles to the successful application of the gas turbine in the electricity supply market in both North America and worldwide. The paper will examine the historical background leading up to these changes and will discuss the predicted future price levels for gas turbine fuels. Alternative fuels will also be discussed. The paper will also discuss the challenges facing the large frame gas turbine with respect to the technical improvements that will be required to lower emissions and capital costs, while improving efficiency and potentially capturing and sequestering carbon dioxide.


Author(s):  
R. G. Mills ◽  
K. W. Karstensen

Adverse consequences of losing electrical power to complex electronic and fire control equipment, or of the sudden variations of shore power, cause naval combatants to operate two generators most of the time, each at light load where specific fuel consumption of simple-cycle gas turbines is particularly high. The recuperated gas turbine with variable power-turbine nozzles has a much better specific fuel consumption, especially at part load. Herein described is a compact recuperated gas turbine with variable power-turbine nozzles designed for marine and industrial use, suitable with or without intercooling. These features yield a specific fuel consumption that is comparable to marine diesels used for generator drive, and essentially flat across the entire usable load range.


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