The History of Shochu Distillery Waste Recycling in Miyakonojo City, Miyazaki Prefecture - September 1997

The History of Shochu Distillery Waste Recycling in Miyakonojo City, Miyazaki Prefecture - September 1997

In 1997, Kirishima Brewery in Miyakonojo City, Miyazaki Prefecture, and Kajima Corporation jointly developed a methane fermentation system that utilizes shochu distillery by-products. This technology converts 70% of shochu lees into methane gas and 30% into compost. The methane gas generated met about 50% of the total thermal energy demand of the factory. The composted residue was utilized in local agriculture, promoting soil fertility. This initiative set a new standard in waste management for the shochu brewing industry and served as a model case responding to the ban on ocean dumping scheduled for 2001.

Progress in the 2000s

In 2003, Kirishima Brewery began operating a plant for methane fermentation treatment of shochu lees, though initial instability led to temporary halts in shochu production. Through collaborative research with Kajima Corporation, a new plant was introduced in 2006, capable of stably processing approximately 650 tons of shochu lees daily. The biogas produced was used as fuel for the factory, contributing to an annual reduction of approximately 3,000 tons of CO₂.

Advancements in the 2010s

In 2012, prompted by the introduction of the Feed-in Tariff (FIT) system for renewable energy, Kirishima Brewery installed power generation facilities to utilize surplus biogas. In 2014, "Sweet Potato Power Generation" began, producing about 7 million kWh of electricity annually (equivalent to about 2,000 households). This electricity was sold to Kyushu Electric Power, generating approximately 200 million yen in annual revenue. Additionally, compost extracted from shochu lees was actively used in local agriculture, greatly contributing to soil enrichment.

Kirishima Brewery further promoted the optimization of its production processes and the reduction of environmental impact by upgrading its composting facilities and energy recovery systems. This enabled the factory to meet most of its energy needs through self-generated energy.

Efforts in the 2020s

In the 2020s, the brewery processed approximately 850 tons of shochu lees daily across all its factories, generating about 34,000 cubic meters of biogas daily. This amount is equivalent to the energy needs of about 22,000 households. The head office's expanded factory and the Shibita Second Factory fulfilled 60% of their annual fuel needs with biogas, achieving an annual CO₂ reduction of approximately 4,500 tons. Part of the biogas generated was used for power generation, supplying electricity to households.

In 2023, the "Kirishima Sweet Potato Seedling Production Center 'Imo Terrace'" began operations, supplying healthy seedlings to 1,200 registered farmers. This marked the brewery's evolution into a "circular economy company" capable of managing everything from raw material production to waste recycling.

Conclusion

Kirishima Brewery's efforts have successfully utilized shochu production by-products, reduced environmental impact, and significantly contributed to the sustainability of local communities. This history is widely regarded as a pioneering case that serves as a model for other companies aiming to transition to a circular society.