New technology converts sludge into biofuel

The Swedish Energy Agency has granted C-Green Technology AB nearly SEK 22.7 million to build a full-scale plant that converts industrial biosludge into biofuel. The project will be carried out in cooperation with StoraEnso in Finland. Approximately 13 GWh renewable biofuel will be produced annually, at the same time as the mill's greenhouse gas emissions will be reduced by the equivalent of 7.000 tons of CO2 per year.

Photo: C-Green

C-Green Technology has developed a new technology that transforms large amounts of wastewater sludge into something significantly more valuable. The process uses a technique called hydrothermal carbonization, which is based on nature's own way of breaking down complex organic compounds into coal.

By treating the sludge with pressure and heat, C-Green's process is able to achieve something that usually takes nature millions of years. The result is a dry and clean biocoal that works well as a biofuel.

–After several years of work in the lab and with smaller prototypes, it's exciting to now build the first industrial full-scale plant. With our innovative solution, we are convinced that, in principle, we can solve the problems surrounding sludge management today, while at the same time making a significant contribution to protecting the climate and the environment, says Erik Odén, CEO of C-Green.

Sludge is a by-product from industry, agriculture and municipal wastewater treatment plants. Handling the sludge presents a difficult problem because it is very wet, it can consist of as much as 85 percent water, and may also contain environmentally harmful substances. In addition, large amounts of the greenhouse gases methane and nitrous oxide are emitted from the sludge when it biodegrades.

–C-Green's solution can make a significant contribution to reducing greenhouse gases because it has a commercial potential globally. In this project, the technology will be verified in full scale, and it will then be ready for large-scale distribution on the market, says Leif Lyckebäck, business developer at the Swedish Energy Agency.

The StoraEnso mill in Heinola Finland produces fluting (corrugated board material) and the new plant will convert about 25,000 tons of the mill's biosludge per year into biocoal. The biocoal will be used in the power boiler of the mill and to heat the nearby city of Heinola, with approximately 19,000 inhabitants. The plant in Heinola is expected to become operational during the first half of 2019.

About the Swedish Energy Agency's support for individual, market-oriented projects

The Swedish Energy Agency offers support to SMEs for industrial verification and commercialization of new energy innovations (including pilot and demonstration projects). The company must demonstrate that their solution has solid business potential and can be scaled up internationally, thus contributing to more Swedish jobs, increased export revenues and transition of the global energy system.

About C-Green Technology AB

C-Green is a Swedish process engineering innovation company that has developed a complete solution to efficiently convert large amounts of sludge into biocoal. The C-Green process is based on hydrothermal carbonization and has been further developed to function continuously and with almost no need for external energy. The biocoal produced is a dry, high-quality biofuel that does not emit any odors or greenhouse gases. C-Green's solution is an excellent way to solve the sludge problem in major industries, wastewater treatment plants and agriculture.