Sorigué is progressing with the installation of equipment to process the wastewater generated at the Castellar del Vallès and Sant Celoni WWTPs, transforming it into biogas.  

These projects are funded by the Next Generation funds and are scheduled to be completed by the end of September, in line with the deadlines set by the Recovery, Transformation, and Resilience Plan (PERTE).  

Once the work is finished, the Consorci Besòs Tordera – which manages both WWTPs – will be able to use the biogas to generate electricity and thereby reduce the facilities’ electricity consumption.  

Construction progress  

Sorigué’s Water and Industry division, a specialist in this field, has already installed the main equipment – the digester, cogeneration engine, and boiler – at both the Castellar del Vallès and Sant Celoni WWTPs.  

The new digesters are metallic, a material that is uncommon in urban wastewater treatment plants, where concrete is generally used. However, the process remains the same: sludge from wastewater treatment enters the anaerobic tank, where mesophilic bacteria act in a “cow’s stomach” effect, enabling energy recovery.   

The resulting biogas, with a methane content between 45% and 60%, feeds the engines that produce electricity.  

As an expert in this circular economy process, Sorigué currently manages biogas production at the Vallbona de Anoia and Montornès del Vallès WWTPs and handles maintenance of the efficient thermal sludge treatment plant at the Rubí WWTP, all in Catalonia.  

At the same time as its work for the Consorci Besòs Tordera, Sorigué is also expanding the capacity of the waste treatment plant in the Vallès Oriental region (Barcelona) by installing two new digesters.  

From biogas to biomethane  

Sorigué has taken a further step in organic waste processing by contributing its expertise to the Noguera Renovables project.  

This project utilises 250,000 tonnes of livestock waste per year to produce biogas, which is then purified to obtain high-quality biomethane for injection into the National Gas Network.  

The project is a partnership between Sorigué, Axpo Iberia, and Torre Santamaría, with the goal of producing 100 GWh per year.