Japan’s Hepco to test torrefied wood pellet co-firing

Japanese utility Hokkaido Electric Power (Hepco) plans to carry out a coal and heat-treated wood pellet co-firing test at its Tomato-Tasuma thermal power plant in November.

The company is planning to co-fire up to 10pc of capacity from torrefied wood pellets with coal at the 700MW Tomato-Tasuma No.4 unit in Japan's northernmost Hokkaido prefecture. It will consume several thousands tonnes of torrefied pellets in the first combustion trial for a week with Hepco to consider future co-firing tests. Hepco has yet to announce when it aims to start commercial operations of biomass co-firing and where it will buy the feedstock from.

The utility also plans in the future to co-fire coal and torrefied pellets with ammonia. The co-firing projects will contribute to its decarbonisation plan, with it aiming to achieve net zero carbon dioxide emissions for all its power generation by 2050.

Heat-treated pellets have a higher calorific value compared with typical white wood pellets, with torrefaction one of the technologies it can be produced with. The fuel has better water resistance and grindability than white pellets and shares many characteristics with coal. But companies have in the past raised concerns about the high production costs of heat-treated pellets.

Fellow Japanese utilities Tohoku Electric Power and Hokuriku Electric Power are also considering commercial operations of coal and heat-treated wood pellet co-firing at their thermal power plants.

Japanese energy firm Idemitsu will start torrefied pellet production of 120,000 t/yr in Vietnam in December this year, following several postponements. It is planning to increase its output to 300,000 t/yr within three years with a final target of 3mn t/yr by 2030.

By Takeshi Maeda