History of Sugarcane Utilization in Miyako Island - 1996 to 2020s

History of Sugarcane Utilization in Miyako Island - 1996 to 2020s

Situation in 1996
On Miyakojima Island (present-day Miyakojima City), the construction of a recycling-oriented society utilizing local resources was underway, and the effective use of sugarcane pomace (bagasse) was attracting attention. In that year, plans were made to construct a plant to process approximately 1,000 tons of bagasse per year, based in Hirara City (present-day Hirara area) and Jobe Town. The project was jointly undertaken by the local Miyako Sugar Corporation and Oji Paper, a major paper manufacturer, and was conceived to reuse bagasse as pulp and organic fertilizer.

In addition, an "ecology park concept" was underway in Shimoji Town and the Yonaha area, combining bagasse with shochu (distilled spirit) lees and cattle manure. An environmental impact assessment was conducted in accordance with the PA Law (Planning and Implementation Law Prioritizing Environmental Preservation), which set a goal of reducing the project's overall carbon dioxide emissions by approximately 2,000 tons per year.

Current Status in the 2020s
In the 2020s, about 300000 tons of sugarcane is processed annually at the sugar factory in Miyakojima City, and about 9000 tons of bagasse is generated as a byproduct of this process. This bagasse is used for the following purposes

1. energy use: Bagasse is used to fuel the sugar mill's boilers, providing approximately 60% of the mill's energy needs.
Composting: A portion of the bagasse is composted and provided to local farmers. This reduces the use of chemical fertilizers by 20% and increases the organic content of the soil.

The local Miyako Sugar Corporation is considering the production of biomass fuel and high-function pulp for further effective use of bagasse. In addition, a demonstration experiment of biomass power generation using bagasse as a feedstock is being conducted in Jobe-cho in cooperation with Okinawa Electric Power Co. This power generation facility is expected to supply enough electricity for approximately 3,000 households annually, contributing to the improvement of energy self-sufficiency in the region.

Environmental Impact and Challenges
These efforts have resulted in a reduction of approximately 5,000 tons of carbon dioxide emissions per year. In addition, the use of bagasse-derived compost has improved sugarcane yields by more than 10%, dramatically increasing agricultural productivity. However, further technological innovation and the establishment of a stable supply system remain challenges.

Future Prospects
Miyakojima City is focusing on developing new applications for bagasse in cooperation with research institutes and companies. For example, wide-area resource management is underway, including sugarcane supplied from remote islands such as Ikema and Tarama. This is expected to make Miyako Island a forerunner of a sustainable regional model that can be expanded to other regions.