Climate friendly sludge gas treatment plant opened in Brazil

Barbara Waelkens from Fraunhofer IGB fuels the very first service vehicle using the biomethane acquired; Image: Fraunhofer IGB

Barbara Waelkens from Fraunhofer IGB fuels the very first service vehicle using the biomethane acquired; Image: Fraunhofer IGB

In December, the Brazilian municipality of Franca put into operation a new sludge gas treatment plant to process sludge gases produced at its sewage treatment plant. The gases treated by the facility can subsequently be used as biofuel for transport purposes. The facility has the capacity to produce up to 2,000 Nm3 of biomethane daily. Just before it was completed, a group of delegates from Franca travelled to Germany for relevant training and to learn how biogas is used at sewage treatment plants and biogas plants in Germany.

The project Energy Recovery from Sludge Gases at a Municipal Sewage Treatment Plant for Transport (Beneficiamento de Biogás gerado em ETE para Utilização como Combustível Veicular), supported by the International Climate Initiative (IKI), came to a close at the end of the year. With the ultimate goal of reducing greenhouse gas emissions, a model project was conducted in cooperation with the Brazilian water supply company SABESP (Companhia de Saneamento Básico do Estado de São Paulo) and the Fraunhofer Institute for Interfacial Engineering and Biotechnology (Fraunhofer IGB). The project, which was launched in 2009, aimed to process sludge gases into an end product of the same quality as natural gas. SABESP will be able to use the biomethane acquired through this process to fuel and operate the water company’s fleet of service vehicles.

The facility in the Brazilian municipality of Franca, as seen from one of the sludge towers; image: Fraunhofer IGB

The cooperation in the scope of the project covered all the steps from preliminary evaluation and planning to the construction and commissioning of the sludge gas facility that was integrated into Franca’s sewage treatment plant. Training courses on correct technical operation of the facility were also included. In October this year, eight delegates from Brazil travelled to Germany to receive the necessary training. The delegation visited sewage treatment plants featuring sludge digestion and sludge gas utilisation facilities in the cities of Heidelberg and Edenkoben, and took part in training courses on biogas treatment.

The facility in Franca started operations at the beginning of December. It has the capacity to process 120 Nm3/h of crude gas and it can produce up to 2000 Nm3/d of biomethane. The very first service vehicle has already been refuelled using the resulting gas. With a grade of 98 per cent methane, the facility is able to produce very high-quality biofuel. The facility now serves as a best-practice project with the potential to inspire other similar projects in the years to come. Prior to its commissioning, the facility had already generated a great deal of interest in other projects in Brazil. An inauguration ceremony for the facility has been planned for February 2018.