VERY LITTLE INFORMATION Early 2013 marked the beginning of research into use of ad-vanced biomass as a potential fuel source for the Thunder Bay generating station. Test burns would be needed in order to try out the fuel in the current system, but research was needed to determine what modifications, if any, needed to be done before test burns could be completed. “Our research on advanced biomass showed little informa-tion was available on advanced biomass used for energy genera-tion,” Rollins explains. “For example, there was no information on using advanced biomass with the pulverizers installed at OPG Thunder Bay, or pretty much any type of pulverizer for that matter.” OPG had to turn to industry stakeholders in order to provide its own research into the prospect of using the fuel source. They first commissioned an equipment manufacturer in the United States, who had its own pilot-scale facility, to run the tests. Two types of advanced biomass were tested, but one performed much better than the other. That testing was followed by the commissioning of multiple safety studies to analyze any issues that could occur using the coal system for the biomass. Additionally, material handling experts were brought in to track the pellets from their arrival on site to the moment they are pulverized, looking for any upgrades that were needed to optimize the process. The results were the discovery of three areas needing improvement: stronger belt scrapers to remove more material from the conveyor system, improvements to the grounding of all system components and an upgrade of the dust suppression system. There was also a question of the risks surrounding elec-trostatic discharge (ESD) in the facility with the transition to a wood-based fuel. The coal bunkers were the particular area of concern, identified as the one location in the system where ESD was seen as a potential hazard. Officials at OPG located a company that specialized in fire and explosion prevention, with experience in ESD. That company recommended that OPG increase the humidity in the coal bunkers to 55 per cent to all but eliminate any potential ESD issues. The first round of testing at the OPG site involved using one mill to prove the concept, as well as closely monitor the dust in the operation. The positive results from that testing led to the addition of the second mill the next day, this time testing to en-sure that the desired throughput could be reached. Once again, the testing proved very positive, as the fuel was handled safely, milled and full load was achieved. The third and final test was to test fuel capabilities during winter. That final test run took place in January, when temperatures in Thunder Bay are often in the -20 C to -40 C range. It turned out that, in colder temperatures, the advanced biomass actually handled better than coal. Six months following the final test, full approval to go ahead with the conversion was given. SECURING A FUEL SOURCE Kedel pellet boilers are NOW AVAILABLE IN CANADA! Save 20% to 60% on heating costs compared to fossil fuels Distributed in Québec and Ontario by The Hydronic Store www.thehydronicstore.ca •(450) 601-5374 [email protected] For all other provinces: www.kedelboilers.com • (207) 370-2690 [email protected] Dealer and distributor inquiries welcome With little production taking place in North America beyond bench-scale, OPG was forced to look to potential advanced biomass resources in the European market. They connected with Arbaflame, located in Oslo, Norway, which eventually became the plant’s fuel supplier. The Arbapellets are water resistant and carry a very low self-ignition risk. They carry a 40 per cent lower volume than white pellets with the same energy content. The steam-treated, thermal-processed pellets contain approximately 75 per cent less nitrogen oxide than coal emissions and virtually no sulphur dioxide. OPG Thunder Bay has a contract in place with the Independent Electricity System Operator (IESO), which is tasked with ensuring there is enough power on the grid to meet the demands of Ontario consumers. IESO and OPG signed a contract based on the expected need for power from the plant, dictating the amount of fuel needed annually for power generation. Boyko and his team were able to approach Arbaflame to secure a contract for 2015 for the necessary fuel capacity based on the demands on the IESO contract, resulting in the ability to move forward with the conversion project. THE TRANSITION The conversion itself was a smaller scope than Atikokan, thanks in large part to the experience gained on that project, enabled by the properties of the fuel and the diligence of the project team. “The project team did a very solid risk assessment, having known what some of the areas to focus on were because of the experience from the Atikokan project,” said Brent Boyko, director of biomass business development for OPG. Initially, there was a belief that a rigorous cleanup program would need to be implemented based on the dust created by the NOVEMBER/DECEMBER 2015 12 Canadian BIOMASS
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