Biomass Reburning: Modeling/Engineering Studies. Quarterly Report October 1 - December 31, By Vladimir M. Zamansky

Transcription

1 DE-FC26-97FT Biomass Reburning: Modeling/Engineering Studies Quarterly Report October 1 - December 31, 1997 By Vladimir M. Zamansky Work Performed Under Contract No.: DE-FC26-97FT97270 For U.S. Department of Energy Office of Fossil Energy Federal Energy Technology Center P.O. Box 880 Morgantown, West Virginia By Energy and Environmental Research Corporation 18 Mason Irvine, California 92618

2 Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

3 BIOMASS REBURNING: MODELING/ENGINEERING STUDIES Quarterly Report No. 1 for Period October 1 - December 31, 1997 Prepared by: Vladimir M. Zamansky January 20, 1998 DOE Contract No. DE-FC26-97FT Submitted by: Energy and Environmental Research Corporation 18 Mason, Irvine, CA 92618

4 ABSTRACT Reburning is a mature fuel staging NO x control technology which has been successfully demonstrated at full scale by Energy and Environmental Research Corporation (EER) and others on numerous occasions. Based on chemical kinetic modeling and experimental combustion studies, EER is currently developing novel concepts to improve the efficiency of the basic gas reburning process and to utilize various renewable and waste fuels for NO x control. This project is designed to develop engineering and modeling tools for a family of NO x control technologies utilizing biomass as a reburning fuel. Basic and advanced biomass reburning have the potential to achieve % NO x control in coal fired boilers at a significantly lower cost than SCR. The scope of work includes modeling studies (kinetic, CFD, and physical modeling), experimental evaluation of slagging and fouling associated with biomass reburning, and economic study of biomass handling requirements. Project participants include: EER, FETC R&D group, Niagara Mohawk Power Corporation and Antares, Inc. Most of the combustion experiments on development of biomass reburning technologies are being conducted in the scope of coordinated SBIR program funded by USDA. The first reporting period (October 1 - December 31, 1997) included preparation of project management plan and organization of project kick-off meeting at DOE FETC. The quarterly report briefly describes the management plan and presents basic information about the kick-off meeting. iii

5 TABLE OF CONTENTS Section Page EXECUTIVE SUMMARY Introduction Project Management Plan Technical Approach Overview and Objectives Scope of Work Project Schedule Phase II USDA SBIR Project Project Kick-Off Meeting iv

6 LIST OF FIGURES Figure Page Figure 1. Organizational structure of the R&D program v

7 EXECUTIVE SUMMARY This project is designed to develop engineering and modeling tools for a family of NO x control technologies utilizing biomass as a reburning fuel. Basic and advanced biomass reburning technologies have the potential to achieve % NO x control in coal fired boilers at a significantly lower cost than SCR. Project participants include: Energy and Environmental Research Corporation (EER), FETC R&D group, Niagara Mohawk Power Corporation (NMPC) and Antares, Inc. The project consists of seven tasks: 1. Kinetic Modeling of Biomass Reburning 2. Computational Fluid Dynamics (CFD) Modeling 3. Physical Modeling 4. Biomass Preparation Economics 5. Evaluation of Slagging and Fouling 6. Reburning vs. Cofiring Evaluation 7. Project Management and Reporting The first reporting period (October 1 - December 31, 1997) included preparation of project management plan and organization of project kick-off meeting at DOE FETC. The quarterly report briefly describes the management plan and presents basic information about the kick-off meeting. This FETC project is conducted in close coordination with EER's Phase II SBIR project funded by USDA. The division of tasks between the two projects was thought out to keep process optimization and design tasks within the SBIR project. The FETC project involves modeling activities, economic studies of biomass handling, and experimental evaluation of slagging and fouling. The overall objective of the total R&D program (both USDA and DOE projects) is to develop information and know how to move the technology to the full scale demonstration. Specific objectives of the FETC project include: Develop engineering modeling tools for application of biomass reburning Evaluate slagging and fouling caused by biomass reburning Determine economics of biomass handling The project started on October 1, 1997 and will be conducted over a two-year period. Biomass reburn kick-off meeting was organized by EER and conducted at FETC, Pittsburgh, PA, on November 5, The goal of the meeting was to discuss the general project plan, objectives, deliverables, coordination of the DOE FETC and USDA SBIR programs, specific activities of participants, and coordination of work conducted in participating organizations. Representatives of the following organizations attended the meeting: EER, FETC, NMPC, Antares, and Parsons Power Group. Meeting agenda included the following presentations: Introductory Remarks: FETC Objectives in Biomass Reburning; EER Overview and Reburning Experience; Project Technical Background, Objectives, and Work Plan; OST FETC Experimental Capabilities and Work Plan; OST FETC CFD Modeling Capabilities and Work Plan; NMPC Objectives and Potential Technology Demonstration Site; and Antares Work Plan. 1

8 1.0 Introduction This project is designed to develop engineering and modeling tools for a family of NO x control technologies utilizing biomass as a reburning fuel. Basic and advanced biomass reburning technologies have the potential to achieve % NO x control in coal fired boilers at a significantly lower cost than SCR. Project participants include: Energy and Environmental Research Corporation (EER), FETC R&D group, Niagara Mohawk Power Corporation and Antares, Inc. The project consists of seven tasks: 1. Kinetic Modeling of Biomass Reburning 2. Computational Fluid Dynamics (CFD) Modeling 3. Physical Modeling 4. Biomass Preparation Economics 5. Evaluation of Slagging and Fouling 6. Reburning vs. Cofiring Evaluation 7. Project Management and Reporting The first reporting period (October 1 - December 31, 1997) included preparation of project management plan and organization of project kick-off meeting at DOE FETC. The quarterly report briefly describes the management plan and presents basic information about the kick-off meeting. 2.0 Project Management Plan 2.1 Technical Approach Overview and Objectives The use of biomass in reburning technologies can provide an attractive option for power plant operators. If an appropriate biomass material is available with reasonable transportation expenses, they can use it for inexpensive NO x control, or they can switch to other reburning fuel, 2

9 such as gas or coal. Figure 1 presents organizational structure of the total R&D program, including both this DOE FETC project and the Phase II SBIR USDA project. The DOE FETC project will be performed jointly by EER team, FETC R&D personnel, Antares, and Niagara Mohawk Power Corporation (NMPC). Both projects will be conducted in close coordination with each other. The division of tasks between the two projects was thought out to keep process optimization and design tasks within the USDA Phase II SBIR project. The DOE FETC project involves modeling activities (chemical kinetic, computational fluid dynamics, and physical modeling), economic studies of biomass handling, and experimental evaluation of slagging and fouling. The overall objective of the total R&D program (both USDA and DOE projects) is to develop information and know how to move the technology to the full scale demonstration. Specific objectives of the DOE FETC project include: Develop engineering modeling tools for application of biomass reburning Evaluate slagging and fouling caused by biomass reburning Determine economics of biomass handling 2.2 Scope of Work The project includes 7 tasks: 1. Kinetic Modeling of Biomass Reburning 2. Computational Fluid Dynamics (CFD) Modeling 3. Physical Modeling 4. Biomass Preparation Economics 5. Evaluation of Slagging and Fouling 6. Reburning vs. Cofiring Evaluation 7. Project Management and Reporting 3

10 The technical approach and scope of work for each task are briefly described below. USDA SBIR Phase II Project DOE FETC Project USDA SBIR DOE FETC Niagara Mohawk C. Cleland P. Goldberg P. Strangway, M. Robert EER Support : EER OST Group FETC R. Seeker V. Zamansky V. Zamansky Antares R. Payne M. Freeman E. Gray M. Booth EER CFD modeling Combustion Tests Engineering Studies Slagging/fouling Kinetic modeling Cofiring/reburning P. Maly D. Moyeda Size reduction Physical modeling Biomass handling Preparation of the facility Economic analysis M. Freeman, M. Mathur M. Sheldon, D. Moyeda Optimization of reburning Design methodology Optimization of ABR Figure 1. Organizational structure of the R&D program. Task 1. Kinetic Modeling of Biomass Reburning The objective of this task will be to create a model for predicting the NO control performance via reburning and advanced reburning based on ultimate and proximate analysis. The model will include both homogeneous reactions in the reburning and overfire air zones and heterogeneous processes on the surface of biomass particles with formation of char and tar compounds. The modeling results will be compared with experimental data on biomass reburning with different biomass fuel compositions. Task 2. CFD Modeling This task will be conducted by FETC research staff with the use of FLUENT, a CFD package 4

11 for modeling reacting flows in combustion systems. The calculations will include assume the individual streams are composed of particles of different sizes and densities; that is, the co-injection will include a stream of larger lighter particles (the biomass) and a second of finer, denser particles (the coal). In addition, some experimental measurements will be conducted at FETC in a small wind tunnel using laser imaging and a 2-component LDV system. Experimental results are useful for scale up and for validating and improving model predictions. Task 3. Physical Modeling In this task of the project, EER will construct a subscale isothermal flow model of the host boiler to be used to demonstrate biomass reburning technology. The physical model will be approximately 1:12 geometric scale and will include all important features of the host site furnace. The model will simulate the region from the burners to the first few tubes banks of the convective pass. The flow model will be used to design injection schemes for the reburning fuel, overfire air, and SNCR agents for the host boiler. Task 4. Biomass Preparation Economics Economics of biomass size reduction will be evaluated by FETC. FETC will evaluate: (a) grinding equipment that could perform the requisite size reduction, (b) blending and feeding techniques, and (c) experience in feeding blended or separate streams to develop some guidelines on these matters. Capital and operating costs for the equipment will be investigated and compared with commercial prices that might be charged by a third party to prepare large quantities of a specification fuel. Task 5. Evaluation of Slagging and Fouling In this task, FETC will perform an experimental analysis of slagging and fouling in biomass reburning. The tests will be carried out in a 500,000 Btu/hr downfired combustion simulator 5

12 equipped with an IFRF-type moveable block swirl burner. Two weeks of testing in this unit will be dedicated to biomass reburning work. One week will focus on waste wood as the biomass, the second on hybrid willow. The impact of biomass reburning on ash deposition (if any) and the resulting deposit properties will be a focal point of the study. Task 6. Reburning vs. Cofiring Evaluation Antares will review the materials handling and processing requirements for the use of biomass as a reburn fuel in a large pulverized coal boiler and evaluate the trade-off and benefits of using all or a portion of the biomass fuel stream for reburn versus the current use of biomass as strictly a supplemental fuel co-fired with coal. With host utility permission Antares would perform the analysis for the hostõs boilers that are currently being considered or developed for biomass co-firing. The results will be generalized for other pulverized coal boilers. Task 7. Project Management and Reporting The DOE FETC project on biomass reburning will deliver formulation of the kinetic model (set of elementary and global reactions included in the mechanism; kinetic modeling results for basic and advanced reburning); results of CFD modeling; results of physical modeling with prediction of NO control performance for a specific boiler; and results of the economic and slagging/fouling studies. All these data will be reduced in coordination with the SBIR results and presented to project cofunders in the form of a comprehensive Final Report. EER will have overall responsibility for project management. Project management and reporting activities will include: (1) preparing and submitting all reports and forms required for the performance of the Cooperative Agreement; (2) coordinating, managing, and integrating the subcontractor efforts and results; (3) integrating and delivering to DOE the final work output of all tasks; and (4) planning and conducting project review meetings. 6

13 2.3 Project Schedule The program started on October 1, Task 7 - Management and Reporting, began on October 1, 1997 and will continue during the whole project. Tasks 1 and 2 - Kinetic Modeling of Biomass Reburning will develop an understanding of the process and support combustion experiments. This task will start in January 1998 and will be completed by December Tasks 2-5 (CFD Modeling, Physical Modeling, Biomass Preparation Economics, and Evaluation of Slagging and Fouling) will start after completion of the combustion tests scheduled in the scope of the SBIR project. Task 6, Reburning vs. Cofiring Evaluation, will be conducted during the summer of 1999 when the results of other experimental and modeling activities become available. Data reduction will proceed with the specific tasks of the program. The final report will be submitted as required by December 20, Phase II USDA SBIR Project As described above, this project will be coordinated with the Phase II USDA SBIR project. The overall objective of the Phase II SBIR project is to experimentally optimize the biomass reburning technologies and conduct engineering design studies needed for process demonstration at full scale. The Phase II program will also be conducted over a two year period, in the same time frame as this FETC project. The Phase II SBIR program will include pilot scale combustion experiments on optimization of process parameters, as well as EPRI TAG economic analysis and engineering studies. Two potential applications of using biomass for NO x control are expected: basic and advanced reburning. The Phase II SBIR project will: 1. Prepare the Boiler Simulator Facility to simulate thermal conditions of a NMPC boiler. 2. Optimize the basic biomass reburning process for specific types of biomass. 3. Optimize the advanced biomass reburning process. 4. Conduct economic analysis using the EPRI-TAG methodology. 7

14 5. Develop design methodology for biomass reburning technologies. 3.0 Project Kick-Off Meeting Biomass reburn kick-off meeting was organized by EER and conducted at FETC, Pittsburgh, PA, on November 5, The goal of the meeting was to discuss the general project plan, objectives, deliverables, coordination of the DOE FETC and USDA SBIR programs, specific activities of participants, and coordination of work conducted in participating organizations. A list of meeting participants follows. EER: FETC: NMPC: Antares: Parsons Power Group: Michael Booth, Vladimir Zamansky Mark Freeman, Philip Goldberg, Robert James, Mahendra Mathur, Robert Patton, Sean Plasynski, Larry Strickland, Suellen VanOotegghem Peter Strangway Kevin Comer, Edward Gray Gary Walbert Meeting agenda included the following presentations: 1. Philip Goldberg, DOE FETC, Coal Science Manager Introductory Remarks: FETC Objectives in Biomass Reburning 2. Michael Booth, EER, Director of Business Development EER Overview and Reburning Experience 3. Vladimir Zamansky, EER, Principal Scientist Technical Background, Objectives, and Work Plan 4. Mark Freeman, DOE FETC, Team Leader OST FETC Experimental Capabilities and Work Plan 5. Mahendra Mathur, DOE FETC, Team Leader OST FETC CFD Modeling Capabilities and Work Plan 8

15 6. Peter Strangway, Niagara Mohawk, Senior Research Fellow NMPC Objectives and Potential Technology Demonstration Site 7. Edward Gray, Antares, Inc., Principal Antares Work Plan The meeting was concluded by general discussion on specific issues of project coordination, such as delivery of the test biomass fuel (furniture sawdust and willow biomass) by NMPC to the EER Test Site in Irvine, CA in December 1997, FETC support of combustion tests at EER (slagging probes); detailed information on the target NMPC full scale unit for configuring of the EER pilot scale facility; etc. After the meeting, the participants conducted a tour of FETC in-house test facilities. 9