Front End Engineering Design and Owner’s Engineer for 25 MW Biomass Cogeneration District Energy Plant, Utilities Company

Doherty Engineering was retained for a 25 MW biomass plant in Ajax, ON. DEI prepared preliminary and detailed feasibility studies for the biomass cogeneration plant and district energy system, comparing business-as-usual versus business with biomass district energy. Subsequent to the studies, DEI completed the front-end engineering and design (FEED) documentation, developed the tender packages under an EPC framework, managed the turnkey tender process and performed the role of Owner’s Engineer during the detailed engineering design and construction phases, which includes the full complement of contract administration services.  

The plant generates high pressure superheated steam (550 psig) from wood-fired stoker type combustors. Steam passes through a back pressure turbine, followed by two condensing turbines, each producing approximately 9 MW. The facility includes all balance of plant equipment, such as deaerator, boiler feed, condensate, chemical treatment, steam condensers, cooling towers, lube oil, hydraulic power, wood fuel conveying systems, and wood fuel storage. This facility is one of the few biomass-fired power plants in Ontario and provides steam to an expansive district steam-heating system in the surrounding area. Highlights of the project include: 

• Three (3) nominal 9 MW steam turbine generators; 

• Two (2) biomass combustor trains; 

• Flue gas heat recovery (near condensing); 

• One (1) 300 MMBTU/hr, 20,000 GPM, 8 cell cross flow cooling tower; 

• Connection to existing steam distribution network 


Services Provided: Feasibility Study, Engineering Design, Owner's Engineer

Specialities: Central Plant

Building Type: Industrial

Location: Ajax, ON, Canada