Carbon Monoxide Emission Improvements From Combustion System Upgrades at the Wheelabrator Portsmouth Refuse Derived Fuel Plant

2012 ◽  
Author(s):  
Samit J. Pethe ◽  
Michael L. Britt ◽  
Scott A. Morrison
Keyword(s):  
Carbon Monoxide ◽  
Electrical Power ◽  
High Elevation ◽  
Waste To Energy ◽  
Cfd Modeling ◽  
Combustion System ◽  
Steam Generation ◽  
Design Concepts ◽  
Refuse Derived Fuel ◽  
Boiler Operation

Wheelabrator Technologies Inc. (WTI) operates a waste-to-energy facility in Portsmouth, Virginia. At full capacity, a total of 2,000 tons/day of refuse derived fuel (RDF) can be fired in four identical boilers to generate a total of 600,000 lb/hr of steam and 60 MW of electricity. The boilers were originally designed to co-fire RDF and coal; however, coal burning capability was removed a few years after commissioning. The plant provides all of the process/heating steam and the majority of the electrical power to the nearby Norfolk Naval Shipyard. Historically, the boilers had not been able to reliably achieve carbon monoxide (CO) emissions compliance. CO emissions experienced during normal boiler operation would be more than twice the mandated emission limit. WTI’s goal was to improve the boilers’ CO emissions performance while achieving sustained boiler operation at higher steam generation and RDF firing rates. WTI contracted Jansen Combustion and Boiler Technologies, Inc. (JANSEN) to evaluate the operation of the boilers, to assess the overall feasibility of meeting WTI’s goals, and to develop design concepts to overcome boiler limitations. The project was initiated by an engineering site visit where boiler operating data was collected and evaluated to develop a baseline of boiler operation. Current and new combustion system arrangements were evaluated with Computational Fluid Dynamics (CFD) modeling. The results confirmed that the root cause of the poor CO emissions performance was the inadequate penetration and mixing of the original overfire air (OFA) system (comprised of multiple rows of small ports on the front and rear furnace walls). CFD modeling also showed increased CO emissions to result from non-uniform RDF delivery profiles generated by the original fuel distributors that were installed at a high elevation over the grate. Modeling of the furnace with larger and fewer OFA nozzles placed on the side walls in an interlaced pattern, and the installation of “new-style” RDF distributors at a lower elevation where the boiler’s original coal distributors formerly were located was shown to significantly improve CO burnout. From December 2010 to May 2011, the new combustion systems were installed on all four boilers. Subsequent testing has shown that CO levels have been lowered by more than 70% and boiler availability has been significantly improved. Nitrogen oxides (NOx) emissions, although slightly higher following the upgrade, are still within the NOx compliance limit. This paper describes the process that led to a successful project, including: data collection and analyses, CFD modeling, equipment design and supply, operator training, and start-up assistance.

Elements of a Successful Waste-to-Energy Boiler Upgrade

2009 ◽  
Author(s):  
Samit J. Pethe ◽  
Chris Dayton ◽  
Marcel D. Berz ◽  
Tim Peterson
Keyword(s):  
Waste To Energy ◽  
Cfd Modeling ◽  
Steam Turbines ◽  
Steam Generation ◽  
Operator Training ◽  
Refuse Derived Fuel ◽  
Energy Plant ◽  
History Of ◽  
Emission Limits ◽  
Combustible Gases

Great River Energy operates a waste-to-energy plant in Elk River, Minnesota. The plant burns 850 tons per day of refuse derived fuel (RDF) in three boilers, and its three steam turbines can produce 32 MW of electricity. In the largest of the three units, the No. 3 Boiler, steam generation was restricted by carbon monoxide (CO) and nitrogen oxides (NOx) emission limits. The plant had an interest in improving the combustion performance of the unit, thereby allowing higher average RDF firing rates while staying within emissions compliance. The project was initiated by an engineering site visit and evaluation. The boiler had a history of unstable burning on the stoker grate, which required periodic natural gas co-firing to reduce CO levels. As an outcome to the evaluation, it was decided to install a new overfire air (OFA) system to improve burnout of combustible gases above the grate. Current and new OFA arrangements were evaluated via Computational Fluid Dynamics (CFD) modeling. The results illustrated the limitations of the original OFA system (comprised of multiple rows of small OFA ports on the front and rear furnace walls), which generated inadequate mixing of air and combustible gases in the middle of the boiler. The modeling illustrated the advantages of large and fewer OFA nozzles placed on the side walls in an interlaced pattern, a configuration that has given excellent performance on over 45 biomass-fired boilers of similar design upgraded by Jansen Combustion and Boiler Technologies, Inc. (JANSEN). Installation of the new OFA system was completed in April of 2008. Subsequent testing of the No. 3 Boiler showed that it could reliably meet the state emission levels for CO and NOx (200 ppm and 250 ppm, respectively, corrected to 7% dry flue gas oxygen) while generating 24% more steam than a representative five month period prior to the upgrade. This paper describes the elements that led to a successful project, including: data collection, engineering analyses, CFD modeling, system design, equipment supply, installation, operator training, and startup assistance.

Operation and Performance of a Fluidized Bed Boiler Firing Municipal Refuse Derived Fuel in Ravenna, Italy

2001 ◽  
Author(s):  
Michael L. Murphy
Keyword(s):  
Electrical Power ◽  
Energy System ◽  
Waste To Energy ◽  
Environmental Controls ◽  
Refuse Derived Fuel ◽  
Fluid Bed ◽  
Municipal Refuse ◽  
Primary Focus ◽  
And Performance ◽  
The City

Abstract In early 1998, the City of Ravenna, Italy, commissioned a fluid bed boiler/waste-to-energy system to combust approximately 50,000 tonnes per year of processed municipal waste and generate electrical power. Much of the fuel preparation and processing equipment was already in place and the primary focus of this project was to implement an environmentally acceptable energy conversion process compatible with the 6.0 tonnes per hour of fuel being processed. The fluid bed boiler system being provided incorporates state of the art environmental controls for abatement of all pollutants, including products of incomplete combustion (PIC’s), NOx, acid gases, and particulates. The project delivers an average of 70,000 pounds per hour of steam to generate approximately 7 MW of electricity.

Simulation of an Industrial Tangentially Fired Boiler Firing Metallurgical Gases

2013 ◽  
Author(s):  
Guangwu Tang ◽  
Bin Wu ◽  
Kurt Johnson ◽  
Albert Kirk ◽  
Chenn Q. Zhou
Keyword(s):  
Electrical Power ◽  
Combustion Process ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Cfd Modeling ◽  
Steel Mill ◽  
Operation Conditions ◽  
Boiler Operation ◽  
Computational Fluid Dynamics Cfd ◽  
Industrial Boilers

In industrial environments, boiler units are widely used to supply heat and electrical power. At an integrated steel mill, industrial boilers combust a variable mixture of metallurgical gases combined with additional fuels to generate high-pressure superheated steam. Most tangentially fired boilers have experienced water wall tube failures in the combustion zone, which are thought to be caused by some deficiency in the combustion process. The challenge faced in this present process is that there are very limited means to observe the boiler operation. In this study, a three-dimensional Computational Fluid Dynamics (CFD) modeling and simulation of an industrial tangentially fired boiler firing metallurgical gases was conducted. Simulation results obtained from the assembled CFD model were validated by industrial experiments. A quick comparison of the flame shape from the simulation to the actual flame in the boiler showed a good agreement. The flow field and temperature distribution inside the tangentially fired boiler were analyzed under the operation conditions, and a wall water tube overheating problem was observed and directly related to the flow characteristics.

Simulation of an Industrial Tangentially Fired Boiler Firing Metallurgical Gases

2014 ◽  
Vol 7 (1) ◽  
Author(s):  
Guangwu Tang ◽  
Bin Wu ◽  
Kurt Johnson ◽  
Albert Kirk ◽  
Chenn Q. Zhou
Keyword(s):  
Electrical Power ◽  
Combustion Process ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Cfd Modeling ◽  
Combustion Model ◽  
Steel Mill ◽  
Operation Conditions ◽  
Boiler Operation ◽  
Industrial Boilers

In industrial environments, boiler units are widely used to supply heat and electrical power. At an integrated steel mill, industrial boilers combust a variable mixture of metallurgical gases combined with additional fuels to generate high-pressure superheated steam. Most tangentially fired boilers have experienced water wall tube failures in the combustion zone, which are thought to be caused by some deficiency in the combustion process. The challenge faced in this present process is that there are very limited means to observe the boiler operation. In this study, a three-dimensional computational fluid dynamics (CFD) modeling and simulation of an industrial tangentially fired boiler firing metallurgical gases was conducted. Eddy dissipation combustion model was applied on this multiple fuel combustion process. Simulation results obtained from the developed CFD model were validated by industrial experiments. A quick comparison of the flame shape from the simulation to the actual flame in the boiler showed a good agreement. The flow field and temperature distribution inside the tangentially fired boiler were analyzed under the operation conditions, and a wall water tube overheating problem was observed and directly related to the flow characteristics.

Energy in the 1980s - Operational experience in nuclear power stations

1974 ◽  
Vol 276 (1261) ◽  
pp. 571-586
Keyword(s):  
Nuclear Power ◽  
Nuclear Energy ◽  
Large Scale ◽  
Electrical Power ◽  
Operating Experience ◽  
Operational Experience ◽  
Original Design ◽  
Safety Requirements ◽  
Design Concepts ◽  
Power Stations

From the first self-sustaining nuclear reaction to the present day represents a span of three decades: within that time large-scale generation of electrical power from nuclear energy has become acknowledged as economic, safe and environmentally acceptable. Within the U .K . 10% of electricity consumed is of nuclear origin. Some of the C.E.G.B. reactors have been in service for over 10 years. The operating experience that has been gained shows how the original design concepts have been ultimately developed. Some of the difficulties encountered and the engineering solutions are presented. Operating experience feeds back to the design philosophy and safety requirements for future nuclear plant. In this way a foundation is provided for the further exploitation of what must become a major source of energy in the next decade.

Plasma Resource Recovery Technology: Converting Waste to Energy and Valuable Products

2005 ◽  
Author(s):  
Pierre Carabin ◽  
Gillian Holcroft
Keyword(s):  
Carbon Monoxide ◽  
Construction Material ◽  
Resource Recovery ◽  
Waste To Energy ◽  
Small Scale ◽  
Cruise Ship ◽  
Plasma Flame ◽  
Fuel Gas ◽  
The Core ◽  
Core Technology

Plasma Resource Recovery (PRR) is a revolutionary technology that can treat virtually any type of waste by combining gasification with vitrification. Vitrification produces inert slag that can be used as a construction material. Gasification produces a fuel gas containing carbon monoxide (CO) and hydrogen (H2), used for cogeneration of electricity and steam. The plasma fired eductor which is the core technology of the PRR system is presently being used commercially on a cruise ship at a scale of 5 TPD. The capabilities of the PRR technology have been demonstrated in a pilot plant, at a rate of up to 2 TPD of various types of waste. Because of the high intensity of the plasma flame and the reduced amounts of gases produced in a gasification system, compared to traditional combustion systems, the PRR system is typically very compact. As such, the PRR technology opens the door for a decentralized, small scale approach to waste management.

scholarly journals Mars™ SoLoNOx Combustion System CFD Modeling

1995 ◽  
Author(s):  
Matthew E. Thomas ◽  
Mark J. Ostrander ◽  
Andy D. Leonard ◽  
Mel Noble ◽  
Colin Etheridge
Keyword(s):  
Gas Turbine ◽  
System Development ◽  
Cfd Modeling ◽  
Cfd Analysis ◽  
Combustion System ◽  
Design Environment ◽  
Turbine Engine ◽  
Combustion Modeling ◽  
Premix Combustion ◽  
Industrial Gas Turbine

CFD analysis methods were successfully implemented and verified with ongoing industrial gas turbine engine lean premix combustion system development. Selected aspects of diffusion and lean premix combustion modeling, predictions, observations and validated CFD results associated with the Solar Turbines Mars™ SoLoNOx combustor are presented. CO and NOx emission formation modeling details applicable to parametric CFD analysis in an industrial design environment are discussed. This effort culminated in identifying phenomena and methods of potentially further reducing NOx and CO emissions while improving engine operability in the Mars™ SoLoNOx combustion system. A potential explanation for the abrupt rise in CO formation observed in many gas turbine lean premix combustion systems is presented.

Waste-to-Energy Technologies Applied for Refuse Derived Fuel (RDF) Valorisation

2018 ◽  
pp. 641-647 ◽  
Author(s):  
André Ribeiro ◽  
Margarida Soares ◽  
Carlos Castro ◽  
André Mota ◽  
Jorge Araújo ◽  
...  
Keyword(s):  
Waste To Energy ◽  
Energy Technologies ◽  
Refuse Derived Fuel
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