Arizona DEQ works on air permit for biomass-fueled power plant

The Arizona Department of Environmental Quality is taking comment until Jan. 27 on a draft air permit that would allow Concord Blue Eagar LLC to construct a biomass-fueled power generating station and biochar production facility.

The facility is to be located in Eagar, Apache County, Arizona. 

The woody biomass feedstocks for the plant include waste wood from area mills (ranging in size from small pieces of wood to sawdust), small diameter whole logs, and woody debris from community slash piles. Large items will be screened out and intermittently chipped or ground in a mobile diesel‐fired horizontal chipper, as needed. Tractor trailers will deliver wood chips and whole logs for storage and processing at the project site.

The processing includes an air density separator for removal of rocks and heavy items and a dust collector to treat the exhaust air from a cyclone situated on top of a 24-hour storage silo.

Undried biomass chips are to be conveyed from the 24-hour storage silo to a multi-stage indirect thermal dryer using circulating thermal oil heated by reciprocating engine waste heat. Dried chips are conveyed into a static mixing column where the ceramic heat carrier balls and chips are mixed together and fed into the Pyrolyzer where the wood waste is converted through oxygen‐free thermolysis to a raw producer gas and char. The raw producer gas rises to the Higher Temperature Reformer where increased heat and chemical reactions convert the low grade producer gas into a high quality raw syngas.

A portion of the reformed and cleaned syngas is used in a multi‐fuel process burner to reheat the ceramic beads to the proper operating temperature, making the facility self‐sustaining.

The electrical generating equipment consists of two lean burn reciprocating engines fired by the synthesized gaseous fuel produced by the thermolysis of the biomass. Cleaned syngas is flared for two to three hours during startup until it reaches the specified quality to combust in the two reciprocating engines.

The thermolysis of the biomass results in syngas and biochar. The biochar and ceramic heat carrier balls exit the Pyrolyzer and are separated through screening. The heat carrier balls are mechanically lifted to the Carrier Ball Heater and the biochar is conveyed via a cooling auger to a short‐term holding bin. Biochar is transferred to a cross auger and then is deposited into the 2.5-day storage silo. The silo will be kept under negative pressure by the dust collector discharge fan and connected by a dust discharge pipe. The bagging operation also occurs under negative pressure, controlled by a high static pressure/low load system.

Each of the two engines would be 7.187 MMBtu/hr, Dresser Rand SFGLD 560 model reciprocating lean burn engines.

The address for Concord Blue Eagar is: 12424 Wilshire Blvd., Suite 660, Los Angeles, CA 90025.

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.