Marubeni aims to reduce emissions for sewage treatment; sludge is burned using technology from Danish startup

Marubeni Corp. is launching a company that will reduce emissions from sewage treatment. Currently, most sewage sludge is burned, which generates carbon dioxide. Marubeni will use technology from a Danish startup to reduce carbon emissions and aims to have a treatment plant up and running in Japan within two to three years.

Sewage sludge is incinerated, dumped in a landfill or composted. Landfills require land to be acquired for landfills, while composted sewage may contain heavy metals or toxic substances that contaminate the soil.

The Danish company AquaGreen Holding ApS has a technology to dry sewage sludge at high temperatures and thermally decompose it by burning gases such as methane and hydrogen, which are created during the purification process. Because fossil fuels are only used to ignite the gases, there is significantly less CO2 emission.

Marubeni will invest in AquaGreen to make the company an equity-method affiliate. It is also considering using the technology to expand into Asia and Australia.

Japan’s sewage industry emits about 6 million tons of CO2 annually from sludge treatment and related processes. The government aims to reduce CO2 emissions by 2 million tons from 2013 levels by fiscal 2030 and is working to increase the efficiency of sewage treatment.

Some large trading companies are involved in sewage treatment. Mitsui & Co. runs a sewage treatment company in Mexico and Sumitomo Corp. has one in Brazil. Some emerging countries do not have well-developed sewage systems and are in dire need of infrastructure. Mitsubishi Corp. has invested in a company that runs water and sewage facilities and is involved in sewage treatment in Japan.