BC Hydro, but the quality of the Conifex plan, combined with the region the power project would supply, made it clear that the project would gain approval from the prov-ince’s power producer. In June of 2011, the Electricity Purchase Agreement and related Load Displacement Agreement (LDA) was completed between Conifex Power Limit-ed Partnership, a wholly-owned subsidiary of Conifex, and BC Hydro. Then in April of 2012, the B.C. Utilities Commission (BCUC) approved the EPA for a minimum of 200GWh of electrical energy annually on a 20-year agreement. The expected net of 230GWh would provide enough power for 24,000 homes. In November of that year, Conifex hit a stumbling block that threatened to derail the completion of the plant. With costs creeping towards the $100 million mark, the company had to suspend its construction plans while it looked to secure long-term financing for the bioenergy plant. At the time, the project was approximately 30 per cent complete, however negotiations Once the bioenergy system is running at capacity, it is expected to generate up to $25 mil. per year from BC Hydro. with an equity partner had fallen apart. It took 10 months, but the company finally secured long-term financing valued at $102.7 million thanks to an agreement with a syndicate of four institutional leaders led by a Canadian chartered bank. TRANSITIONING THE PLANT The Conifex team began the bioenergy project with two objectives in mind ac-cording to Tony Madia, senior vice-presi-dent of operations for Conifex Timber. “Treat fuel like fuel – maximize the value of the fuel that is coming from the sawmill. And we wanted to utilize as much of the equipment as possible, using existing infrastructure if and where possible.” That directive has helped to keep costs in check, incorporating existing infrastructure into the construction of the cogen facility. The result is a facility that has capital costs of approximately $3 million per megawatt versus the $6-$7 million per megawatt that a similar greenfield construction project would realize for capital costs. The Conifex team was able to use the existing boiler and boiler bed combustion system already in place in the pulp and paper mill, and build in the rest of the components around those pieces. The removal of the other pieces of existing pulp and paper mill equipment, the first phase of the construction project, took approximately 8-10 months to remove. The removal of the equipment allowed the company to then focus on putting all of the elements in place to produce an efficient and effective system for turning residues into power. At the start of the process, the trucks dump fuel through the Keith reclaimer sys-tem. Both the trucks and the floors have walking bed designs, allowing the efficient unloading of fuel from the trucks in just seven minutes. The fuel is dumped through the floor into the auger, where the fibre is reclaimed and processed into the shredder. The shredded material is then pneumatically conveyed, blown through the blower and feeder up into the silos. The silos are part of the in-frastructure already onsite that has been utilized for the bioenergy system, as the silos were previously used for pulp storage. Now, fitted with baffles and dampers for explosion prevention and a dust collection system at the top of each one, the silos are used to provide 80,000-90,000ft. 3 of storage capacity for the cogen facility, which represents approximately three-to-four days worth of fuel. At the bottom of each of the silos, a reclaiming auger processes the fibre onto an S conveyor that conveys the material to the hammermills. The hammermills then pulverize the fuel, which is then ready for combustion in the boiler. The cyclonic burners in the boiler use a combination of pilot fuel and oxygen that reacts with the blown in biomass. At the bottom of the boiler is a bubbling, fluidized bed system using sand. Underfire air is blown up through the sand, turning the sand into something reminiscent of bubbling porridge as Madia described it during the tour of Canadian BIOMASS 17
Canadian Biomass May-June 2015: Page 17
