The Effects of Varied Hydrogen Chloride Gas Concentrations on Corrosion Rates of Commercial Tube Alloys Under Simulated Environment of WTE Facilities

2008 ◽  
Author(s):  
Shang-Hsiu Lee ◽  
Marco J. Castaldi
Keyword(s):  
Flue Gas ◽  
Metal Temperature ◽  
Waste To Energy ◽  
Composition Analysis ◽  
Gas Composition ◽  
Gas Temperature ◽  
Elementary Composition ◽  
Corrosion Rates ◽  
Simulated Environment ◽  
Hcl Concentration

In order to clarify the effects of HCl concentrations on corrosion rates of commercial tubing in Waste-to-Energy (WTE) boilers, a corrosion test was made by altering the HCl concentration from 0 to 1000ppm, together with simulated flue gas composition. Three commercial tubing SA178A, SA213 T11 and NSSER-4 samples were investigated under a well controlled thermal gradient where the gas temperature was at 700°C and metal temperatures ranged from 480 to 580°C. The duration of each test was 100 hours. The posttest analyses included observations of surface morphology and elementary composition analysis of corrosion products by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The corrosion rates were acquired by measuring the mass loss of samples after the test. The results showed that the addition of HCl to the flue gas increased the corrosion rates of test samples, but the relation between the HCl concentration and corrosion rate was not linear. The HCl effects on corrosion rates were more prominent when its concentration changed from 0 to 500ppm. In addition, the HCl effects were promoted by the increase of metal temperature in particular when metal temperature was over 560°C.

SYNCOM-Plus: An Optimized Residue Treatment Process

2009 ◽  
Author(s):  
Ralf Koralewska
Keyword(s):  
Flue Gas ◽  
Large Scale ◽  
Treatment Process ◽  
Bottom Ash ◽  
Fine Fraction ◽  
Continuous Operation ◽  
Wash Water ◽  
Waste To Energy ◽  
Gas Composition ◽  
Energy Plant

In a large-scale pilot plant, studies on wet-mechanical treatment of bottom ash using the SYNCOM-Plus process were carried out by MARTIN GmbH in the SYNCOM waste-to-energy plant in Arnoldstein, Austria (approx. 11000 kg/h waste throughput). Granulate of > 2 mm and fine fraction of < 5 mm were produced by dry screening, washing and wet screening. Additionally, sludge was separated from the wash water. The fine fraction and sludge as well as the boiler ash were recirculated into the furnace. In conclusion, the SYNCOM-Plus process meets all requirements which need to be complied with in an optimized and effluent-free commercial residue treatment process for the recovery of industrial products. This paper documents successful continuous operation of the SYNCOM-Plus process in direct connection with bottom ash discharge as well as the effects on combustion, flue gas composition and residue qualities.

Development of a Laboratory-Scale Pilot for Studying Corrosion on MSWI Heat Exchangers

2008 ◽  
Vol 595-598 ◽  
pp. 271-280 ◽  
Author(s):  
Florimonde Lebel ◽  
Christophe Rapin ◽  
Jean François Mareche ◽  
Renaud Podor ◽  
Xavier Chaucherie ◽  
...  
Keyword(s):  
Flue Gas ◽  
Heat Exchangers ◽  
Laboratory Scale ◽  
Waste To Energy ◽  
Metal Loss ◽  
Gas Temperature ◽  
Fireside Corrosion ◽  
The Face ◽  
Corrosion Scales ◽  
Corrosion Mechanisms

The efficiency of Waste-to-Energy (W-t-E) boilers is affected by fireside corrosion of the heat exchangers that involve unexpected shutdown of facilities for repairs and limit the increase of steam conditions used to produce electricity. The parameters governing fireside corrosion are various and mechanisms are very complex, nevertheless, they are relatively well documented in the literature. In this paper, a laboratory-scale corrosion pilot, which reproduces MSWI boilers conditions, is described. The specificity of our approach includes simultaneous simulation of the temperature gradient at flue-gas/tube interface, the velocity of flue-gas and ashes. Corrosion rates obtained on Tu37C carbon steel at a metal temperature equal to 400°C and a flue gas temperatures of 650°C and 850°C (1100 ppm HCl, 110 ppm SO2 and synthetic ashes free of heavy metals) are respectively around 1.6 2m/hour and 5.6 2m/hour. Preferential metal loss, attributed to erosion-corrosion phenomena, is also observed at low flue-gas temperature (T=650°C) on the face exposed at 90° to the flue-gas. The analysis of corrosion scales demonstrates the reproducibility of results and the reliability of corrosion mechanisms determined from experiments, with degradation observed similar to superheater tubes from EfW facilities. Thus, the corrosion pilot developed can be used as an accurate simulator of the environment encountered in MSWI.

Corrosion and Deposits from Combustion of Solid Waste—Part VII: Coincineration of Refuse and Sewage Sludge

1980 ◽  
Vol 102 (3) ◽  
pp. 698-705 ◽  
Author(s):  
H. H. Krause ◽  
P. W. Cover ◽  
W. E. Berry ◽  
R. A. Olexsey
Keyword(s):  
Sewage Sludge ◽  
Stainless Steels ◽  
Cost Effective ◽  
Metal Temperature ◽  
Low Alloy Steels ◽  
Gas Temperature ◽  
Corrosion Rates ◽  
Prevention Measure ◽  
Alloy Steels ◽  
Municipal Refuse

Corrosion probe exposures were conducted in the Harrisburg, Pennsylvania, incinerator to determine the effects of burning low-chloride sewage sludge with municipal refuse. Probes having controlled temperature gradients were used to measure corrosion rates for exposure times up to 816 hours. The effects of exposure time, metal temperature, and gas temperature were studied. The results demonstrated that the addition of the sludge reduced the initial corrosion rates of carbon and low-alloy steels to about half that from refuse alone. Little effect was observed on the rates for Types 310 and 347 stainless steels. An aluminized coating on steel resisted corrosion effectively and offers promise as a cost-effective substitute for expensive alloys. In the range 500–900° F the corrosion rates of carbon steel and T22 increased with temperature while those for the stainless steels decreased. Reducing the flue gas temperature from 1500° F to 1100° F reduced corrosion rates significantly and made them less dependent on metal temperature. The addition of low-chloride sludge to refuse is recommended as a corrosion prevention measure and a waste disposal technique.

Thermodynamic Modelling of the Corrosive Deposits in Oxy-Fuel Fired Boilers

2008 ◽  
Vol 595-598 ◽  
pp. 261-269 ◽  
Author(s):  
B. Bordenet ◽  
Frank Kluger
Keyword(s):  
Flue Gas ◽  
Co2 Emission ◽  
Power Plants ◽  
Thermodynamic Modelling ◽  
Chemical Compositions ◽  
Gas Composition ◽  
Free Atmosphere ◽  
Co2 Emission Reduction ◽  
Combustion Gas ◽  
Corrosion Rates

The aim to reduce the CO2-emissions has triggered the evaluation of new cycle concepts for power plants. For the coal-fired power plants, the oxy-fuel firing is a promising option for CO2- emission reduction. Here, the combustion takes place in a nitrogen-free atmosphere. The oxygen is separated from the air and burned in near-stoichiometric conditions with the fuel. The gas composition is significantly changed, when the combustion is changed from air-fired to oxy-fuel fired condition. For lignite, the carbon dioxide content is raised from 15 to 59vol% and the watercontent from 10 to ~32%. For the same fuel, the SO2-content in the flue gas increases by a factor of 3-4 to ~0.5%. These changed environmental boundary conditions will affect corrosion life of the materials especially on the water walls and the heat exchanger surfaces. Considering the significant changes in the combustion gas, the composition and the occurrence of the corrosive deposits has been evaluated with the thermodynamic modelling program ‘FactSage’. The chemical compositions of the deposits have been modelled for dried lignite from Germany. The results exhibit that the oxy-fuel firing will give a significant change in the atmosphere as well as in the deposit composition. Consequently, the corrosion rates of current used materials in air fired boilers need to be evaluated for the application in oxy-fuel fired boilers.

Advanced Boiler Cleaning Solutions for Increased Boiler Runtime

2011 ◽  
Author(s):  
Brandon Billings ◽  
Greg Rodia ◽  
Ryan Scavone ◽  
Marc Tirkschleit
Keyword(s):  
Temperature Rise ◽  
Flue Gas ◽  
Operating Experience ◽  
Waste To Energy ◽  
Gas Temperature ◽  
Energy Facility ◽  
Custom Design ◽  
Boiler Operation ◽  
Clean System ◽  
Pressure Water

Clyde Bergemann Power Group (CBPG) and Covanta Niagara, a Waste-to-Energy facility (WTE) plagued by boiler cleanliness issues, have collectively worked to implement a Shower Clean System (SCS) trial in Boiler 3’s second pass. The SCS’s cleaning concept is designed to traverse down through the roof of the boiler into a narrow open pass using a custom design water spray nozzle to clean the water walls. A SCS trial assembly was operated at the facility from July 27, 2010 to September 1, 2010. A total of 16 cleaning cycles were performed. During this trial period, on average, the second pass outlet flue gas temperature saw a 62 degrees Fahrenheit (degF) reduction after a cleaning event was performed. Based on years of SCS operating experience, CBPG determined a cleaning event should not be initiated if the temperature rise in the second pass is less than 30 degF. This insures that the second pass would not be over cleaned causing material stress to the water walls. In order to estimate the proper cleaning frequency for Niagara’s permanent SCS, an average second pass fouling rate was calculated. Using the fouling rate and the minimum allowable flue gas temperature rise, a cleaning frequency was estimated. Based on the trial results, the recommended operating frequency of the permanent SCS at Covanta Niagara will employ the Umbrella nozzle in the second pass twice per day or once per shift (12 hours). This recommendation is based on observations of the six week operating trial of the SCS and is subject to change based on myriad variables such as waste characteristics and first pass outlet flue gas temperatures. Typical boiler operation at Niagara utilizes industrial cleanings once per week to extend its boiler runtime. During the six week trial the SCS helped reduce the total number of industrial cleanings necessitated to keep the boiler online. Once a permanent SCS is implemented and used daily, there could be significant benefits to boiler runtime without having a total dependence on industrial cleanings. Becoming more reliant on the SCS to maintain lower boiler flue gas temperatures will result in less costs associated with online boiler cleaning and potentially less damage to the third pass convective surface from less high pressure water washing.

Simulation and Validation of a Mass Burn WTE Boiler Using CFD Modeling

2004 ◽  
Author(s):  
Greg Epelbaum
Keyword(s):  
Flue Gas ◽  
Cfd Modeling ◽  
Design Parameters ◽  
Air Distribution ◽  
Gas Temperature ◽  
Corrosion Rates ◽  
Velocity Surface ◽  
Boiler Tubes ◽  
Chloride Salts ◽  
Simulation And Validation

American Ref-Fuel Company (ARC) spends millions of dollars each year on corrosion related costs in the boilers. The corrosion is caused by chloride salts in the slag that deposit on the boiler tubes, coupled with the high temperatures of flue gas going through the boiler. Corrosion rates are known to be very sensitive to the flue gas temperature and velocity, surface temperature and heat flux through the slag, oxygen in flue gas distribution, etc. These parameters are primarily determined by the firing rate of the boiler, and they are also affected by combustion control and air distribution in the boiler. Some design parameters, such as surface area of refractory, tile, and inconel overlay, also affect the flue gas temperature throughout the boiler, and thereby impact corrosion.

The Effect of Nitrogen in Natural Gas on the NOx Emission From a 90 kW Burner

2010 ◽  
Author(s):  
Antonio Diego-Marin ◽  
Carlos Melendez-Cervantes ◽  
Alejandro Mani Gonzalez
Keyword(s):  
Heat Flux ◽  
Natural Gas ◽  
Flue Gas ◽  
Gas Turbines ◽  
Gas Composition ◽  
Gas Temperature ◽  
Incident Heat Flux ◽  
Thermal Mechanism ◽  
Different Levels

The role of different levels of nitrogen in natural gas on the emissions of NOx was investigated in a furnace. Nitrogen was added to the natural gas in concentrations of 4, 7 and 11% by volume. In addition, a trial was carried out as a baseline with 0.17% N2. The thermal load of the furnace was 90 kW and was kept constant in all four trials. Flue gas temperatures were measured with a small suction pyrometer, as well as incident heat flux with an ellipsoidal radiometer. In addition, flue gas composition was conducted at the stack of the experimental furnace. NOx emissions decreased as nitrogen was added to natural gas. This was due to the reduction of flue gas temperature near the burner zone where the thermal mechanism can play a significant role. With 11% nitrogen in natural gas, the flue gas temperature and the incident heat flux near the burner were the lowest, but the highest at the furnace exit. Therefore, care should be taken to avoid damages in gas turbines or furnaces while burning natural gas with high nitrogen content.

High Temperature Corrosion Resistance of Different Commercial Alloys Under Various Corrosive Environments

2007 ◽  
Author(s):  
Shang-Hsiu Lee ◽  
Marco J. Castaldi
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Metal Surface ◽  
Flue Gas ◽  
Thermal Gradient ◽  
Operating Cost ◽  
High Temperature Corrosion ◽  
Waste To Energy ◽  
Corrosion Rates ◽  
Corrosive Environments

High temperature corrosion is a major operating problem because it results in unscheduled shutdowns in Waste-to-Energy (WTE) plants and accounts for a significant fraction of the total operating cost of WTE plants. Due to the heterogeneous nature of municipal solid waste (MSW) fuel and the presence of aggressive elements such as sulfur and chlorine, WTE plants have higher corrosion rates than coal-fired power plants which operate at higher temperature. To reduce corrosion rates while maximizing the heat recovery efficiency has long been a critical task for WTE operators. Past researchers focused on high temperature corrosion mechanisms and have identified important factors which affect the corrosion rate [1–4]. Also, there have been many laboratory tests seeking to classify the effects of these corrosion factors. However, many tests were performed under isothermal conditions where temperatures of flue gas and metal surface were the same and did not incorporate the synergistic effect of the thermal gradient between environment (flue gas) and metal surface. This paper presents a corrosion resistance test using an apparatus that can maintain a well controlled thermal gradient between the environment and the surface of the metals tested for corrosion resistance. Two commercial substrates (steels SA213-T11 and NSSER-4) were tested under different corrosive environments. The post-test investigation consisted of mass loss measurement of tested coupons, observation of cross-sectional morphology by scanning electron microscopy (SEM), and elemental analysis of corrosion products by energy dispersive spectrometry (EDS). The stainless steel NSSER-4 showed good corrosion resistance within the metal temperature range of 500 °C to 630 °C. The alloy steel SA213-T11 had an acceptable corrosion resistance at metal temperatures up to 540 °C, and the performance decreased dramatically at higher temperatures.

Method for Determining the Change in Gas Turbine Firing Temperature

2021 ◽  
Author(s):  
Bo Wang ◽  
Fabian Rosner ◽  
Ashok Rao ◽  
Lifeng Zhao ◽  
Scott Samuelsen
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Firing Temperature ◽  
Flue Gas ◽  
Pressure Ratio ◽  
Metal Temperature ◽  
Gas Composition ◽  
Blade Surface ◽  
Cooling Flows ◽  
Study Performance

Abstract The maximum firing temperature of a gas turbine (GT) is limited by material constraints. Critical for the operation of the GT is the blade metal temperature, which is impacted by the heat transfer from the combustor outlet gas to the blade surface. In this study, performance characteristics for an H-class-type GT have been established and two correlations for the change in the maximum permissible firing temperature as function of combustor outlet gas composition or flue gas composition and pressure ratio have been derived: I) for detailed GT modeling with cooling flows and II) for simplified GT modelling without specifying cooling flows.

Analysis of Boiler Fouling and Boiler Cleaning Methods at the Commerce Refuse-to-Energy Facility

2007 ◽  
Author(s):  
Matthew A. Eaton
Keyword(s):  
Flue Gas ◽  
Differential Pressure ◽  
Operating Conditions ◽  
Waste To Energy ◽  
Gas Temperature ◽  
Energy Facility ◽  
Rate Of Increase ◽  
On Line ◽  
One Year ◽  
Cleaning Methods

Waste-to-energy boiler fire-side fouling is a major operational issue for many facilities, including the Commerce Refuse-to-Energy Facility. The Commerce Refuse-to-Energy Facility is a 350 ton per day, mass burn waterwall facility that began operation in 1987. Fouling occurs throughout the convection sections with the highest differential pressure occurring across the generating bank. Flue gas differential pressures and temperatures have been tracked and analyzed at the facility for approximately ten years during various operating conditions. It has been determined that the rate of increase of the differential pressure across the generating bank is correlated with flue gas temperature and the extent of fouling. Several different cleaning methods have been used to clear the convection zone of ash deposits, including off-line hydroblasting, on-line hydroblasting, on-line explosives cleaning, sootblowers and sonic horns. Better understanding of the fouling trends and evaluation of cleaning methods has led the facility to use a combination of on-line hydroblasting and explosives cleaning and off-line hydroblasting. The facility is now able to operate one year between planned outages, compared to ten weeks during the initial operation of the facility. Additional savings have also been achieved by reducing induced draft fan load, and possibly a reduction in tube wastage.

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