skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: USE OF COAL DRYING TO REDUCE WATER CONSUMED IN PULVERIZED COAL POWER PLANTS

Technical Report ·
DOI:https://doi.org/10.2172/827154· OSTI ID:827154

This is the sixth Quarterly Report for this project. The background and technical justification for the project are described, including potential benefits of reducing fuel moisture, prior to firing in a pulverized coal boiler. Coal drying experiments were performed with a Powder River Basin coal to measure the effects of fluidization velocity and drying temperature on rate of drying in a batch drying process. Comparisons to computational results using the batch bed drying model show good agreement. Comparisons to drying results with North Dakota lignite at the same process conditions confirm the lignite dries slightly more rapidly than the PRB. Experiments were also carried out to determine the effects of inlet air humidity on drying rate. The specific humidity ranged from a value typical for air at temperatures near freezing to a value for 30 C air at 90 percent relative humidity. The experimental results show drying rate is strongly affected by inlet air humidity, with the rate decreasing with more humid inlet air. The temperature of the drying process also plays a strong role, with the negative impacts of high inlet moisture being less of a factor in a higher temperature drying process. Concepts for coal drying systems integrated into a power plant were developed. These make use of hot circulating cooling water from the condenser, steam extraction from the turbine cycle and thermal energy extracted from hot flue gas, in various combinations. Analyses are under way to calculate the effects of drying system design and process conditions on unit performance, emissions, and cooling tower makeup water.

Research Organization:
Lehigh University (US)
Sponsoring Organization:
(US)
DOE Contract Number:
FC26-03NT41729
OSTI ID:
827154
Resource Relation:
Other Information: PBD: 1 Jul 2004
Country of Publication:
United States
Language:
English