Komatsu successfully converts biomass combustion ash into fertilizer at its Awazu Plant: Contributing to the reduction of industrial waste by recycling forest resources in the Kaga area of Ishikawa Prefecture, Japan

Sep. 14, 2022

 Komatsu Ltd. (President and CEO: Hiroyuki Ogawa) (hereafter “Komatsu”), jointly with Ishikawa Agriculture and Forestry Research Center and ASAHI AGRIA CO., LTD. (President: Masanori Murakami) (hereafter “ASAHI AGRIA”), a manufacturer of fertilizers, has successfully converted wood ash from the biomass boilers in operation at Komatsu’s Awazu Plant in an effort to promote efficient use of forest resources in the Kaga area of Ishikawa Prefecture, and to reduce industrial waste. As a leading model of the public-private sector partnership, the three partners will contribute to the reduction of industrial waste and achievement of carbon neutrality by developing the circulation cycle which extends to agriculture and forestry and the vitalization of agriculture and forestry in Ishikawa Prefecture by using biomass combustion ash as fertilizer. 


  【Left: Biomass combustion ash. Right: Delivery of biomass combustion ash from the Awazu Plant】


 In 2014, Komatsu reached a comprehensive forestry agreement with the Ishikawa prefectural government and the Federation of Forestry Associations of Ishikawa Prefecture to jointly promote the vitalization of local forestry. At its Awazu Plant, since 2015, Komatsu has operated biomass boilers using woodchips as fuel, mainly made of unused left-over wood after forest thinning in the Kaga area, which has facilitated energy savings, energy creation, and environmental impact reduction. Using about 6,000 tons of woodchips annually, Komatsu contributes to promoting sound management of forests and curbing driftwood-caused damages after heavy rain. Meanwhile, Komatsu has disposed of about 20 tons of wood ash generated in the biomass boilers as industrial waste, which has been an issue of concern for the Awazu Plant.

 After focusing attention on potassium and phosphorus, necessary nutrients of agricultural products contained in regular wood ash, at the Awazu Plant, since June 2016, Komatsu has worked with two new partners: the Ishikawa Agriculture and Forestry Research Center and ASAHI AGRIA. Work has centered on content analysis of wood ash generated in the biomass boilers at the Plant and on the verification of fertilizing effects with an eye to converting wood ash to fertilizer. These efforts have found a sufficient amount of active ingredients of fertilizer, including potassium. Cultivation tests have also demonstrated no difference from conventional fertilizers. In August 2017, Komatsu applied for “applications for registration of fertilizer” as biomass combustion ash-based fertilizer with the Ministry of Agriculture, Forestry and Fisheries. Japan has relied on imports of potassium and phosphorus as raw fertilizer materials. Recently, however, safe wood ash, generated mainly in biomass boilers, has attracted keen attention as an alternative raw material accessible in Japan. Against this background, the Japanese government enforced the revised Act on the Quality Control of Fertilizer in the previous fiscal year, which promoted the classification reassessment of fertilizers. Safety-verified wood ash is now classified as a “by-product fertilizer”. Awazu Plant’s biomass combustion ash was registered as by-product fertilizer in April 2022.     

 In April 2022, Komatsu began delivery of Awazu Plant’s biomass combustion ash as raw fertilizer material to ASAHI AGRIA’s Kansai Plant. Komatsu plans to deliver almost all of Awazu Plant’s ash there. Currently, the partner’s plant is busy preparing for the production start-up of fertilizer which uses biomass combustion ash. ASAHI AGRIA is working on launching sales of the fertilizer through the JA Group, the group of Japan agricultural cooperatives, and other sales channels, starting in FY2023. ASAHI AGRIA hopes to contribute to a stable supply of fertilizers for farmers in Ishikawa Prefecture as well as other prefectures. 

 KAGA FOREST ASSOCIATION, which produces wood chips, has also been concerned about disposing of about 2,700 tons of tree roots and barks annually, which are generated during the process of felling and gathering, and are not suitable as a fuel for biomass boilers at the Awazu Plant. In an effort to reduce industrial waste of forest resource recycling in the Kaga area, the ASSOCIATION has worked to make tree roots and barks usable as fuel at large-scale biomass combustion facilities by mixing and crushing them together. Today, the Association engages in mixed crushing by using a large mobile crusher, and supplies crushed chips as fuel to large-scale biomass combustion facilities in Gifu Prefecture and other regions. As a result, it has become possible to completely use wood produced either from trunks or bark of forest and mountain trees, including the use as lumber, plywood, biomass wood chips, and the like.
 When all these series of efforts become widespread, they will hold the promise of not only carbon-neutral energy use of local wood in Ishikawa Prefecture, but also further vitalization of local agriculture and forestry, reduction of industrial waste volume in production, and recycling of generated industrial waste. 



【Left: Prototype fertilizer made from biomass combustion ash. Right: Mixed crushing at KAGA FOREST ASSOCIATION】


 In the current mid-term management plan, Komatsu is committed to minimizing environmental impact through its business, targeting a 50% reduction in CO2 emissions from use of its products and production of its equipment by 2030 (compared to 2010 levels) and a challenge target of achieving carbon neutrality by 2050.Through DANTOTSU Value (customer value creation that generates a positive cycle of improvement of earnings and ESG resolutions), Komatsu will strive to create new values in order to take steady steps forward to the next stage for the workplaces of the future and pass on a sustainable future to the next generation. 



No : 0045(3165)
Corporate Communications Department
Sustainability Promotion Division
Komatsu Ltd.
tel: +81-(0)3-5561-2616

*The information may be subject to change without notice.