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Title: Development and Testing of Industrial Scale Coal Fired Combustion System, Phase 3

Technical Report ·
DOI:https://doi.org/10.2172/923036· OSTI ID:923036

Coal Tech Corp's mission is to develop, license & sell innovative, lowest cost, solid fuel fired power systems & total emission control processes using proprietary and patented technology for domestic and international markets. The present project 'DEVELOPMENT & TESTING OF INDUSTRIAL SCALE, COAL FIRED COMBUSTION SYSTEM, PHASE 3' on DOE Contract DE-AC22-91PC91162 was a key element in achieving this objective. The project consisted of five tasks that were divided into three phases. The first phase, 'Optimization of First Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech Combustor', consisted of three tasks, which are detailed in Appendix 'A' of this report. They were implemented in 1992 and 1993 at the first generation, 20 MMBtu/hour, combustor-boiler test site in Williamsport, PA. It consisted of substantial combustor modifications and coal-fired tests designed to improve the combustor's wall cooling, slag and ash management, automating of its operation, and correcting severe deficiencies in the coal feeding to the combustor. The need for these changes was indicated during the prior 900-hour test effort on this combustor that was conducted as part of the DOE Clean Coal Program. A combination of combustor changes, auxiliary equipment changes, sophisticated multi-dimensional combustion analysis, computer controlled automation, and series of single and double day shift tests totaling about 300 hours, either resolved these operational issues or indicated that further corrective changes were needed in the combustor design. The key result from both analyses and tests was that the combustor must be substantially lengthened to maximize combustion efficiency and sharply increase slag retention in the combustor. A measure of the success of these modifications was realized in the third phase of this project, consisting of task 5 entitled: 'Site Demonstration with the Second Generation 20 MMBtu/hr Air-Cooled Slagging Coal Tech Combustor'. The details of the task 5 effort are contained in Appendix 'C'. It was implemented between 1994 and 1998 after the entire 20 MMBtu/hr combustor-boiler facility was relocated to Philadelphia, PA in 1994. A new test facility was designed and installed. A substantially longer combustor was fabricated. Although not in the project plan or cost plan, an entire steam turbine-electric power generating plant was designed and the appropriate new and used equipment for continuous operation was specified. Insufficient funds and the lack of a customer for any electric power that the test facility could have generated prevented the installation of the power generating equipment needed for continuous operation. All other task 5 project measures were met and exceeded. 107 days of testing in task 5, which exceeded the 63 days (about 500 hours) in the test plan, were implemented. Compared to the first generation 20 MMBtu/hr combustor in Williamsport, the 2nd generation combustor has a much higher combustion efficiency, the retention of slag inside the combustor doubled to about 75% of the coal ash, and the ash carryover into the boiler, a major problem in the Williamsport combustor was essentially eliminated. In addition, the project goals for coal-fired emissions were exceeded in task 5. SO{sub 2} was reduced by 80% to 0.2 lb/MMBtu in a combination of reagent injection in the combustion and post-combustion zones. NO{sub x} was reduced by 93% to 0.07 lb/MMBtu in a combination of staged combustion in the combustor and post-combustion reagent injection. A baghouse was installed that was rated to 0.03 lb/MMBtu stack particle emissions. The initial particle emission test by EPA Method 5 indicated substantially higher emissions far beyond that indicated by the clear emission plume. These emissions were attributed to steel particles released by wall corrosion in the baghouse, correction of which had no effect of emissions.

Research Organization:
Coal Tech Corporation
Sponsoring Organization:
USDOE
DOE Contract Number:
AC22-91PC91162
OSTI ID:
923036
Country of Publication:
United States
Language:
English