Japan’s biggest oil refiner is drawing up plans to consolidate production as domestic demand slumps because of a shrinking population and efforts to cut emissions.

Eneos Holdings has an outline for fusing operations but is still discussing which of its refineries to shutter when, President Takeshi Saito, who took over the helm of the Tokyo-based company in April, said in an interview. Eneos, which expects domestic fuel demand to slump 50% by 2040, has already announced a plan to close one of its 10 refineries next year.

The 60-year-old faces the same challenges of many of his peers around the world as efforts to reduce carbon-dioxide emissions target diesel and gasoline-powered transportation while electric vehicles become more mainstream. That is compounded in Japan by the effects of a shrinking population that further damps demand for fuels in the world’s third-largest economy.