Portuguese company Caima is one of three pulp mills/biorefineries belonging to Altri Group, and produces cellulosic fibers for the textile industry, in the path to a more sustainable and circular textile production.
In 2021, they invested in a new biomass boiler, the “Go Green” project, to become the first Iberian cellulosic fibers producer free of fossil fuels.
At the same time, it should support the energy needs to produce value-added specialties/ green chemicals from a wastewater stream, creating new revenues without the use of additional resources, improving wastewater treatment solutions by removing these by-products from process streams, reducing the industrial site’s ecological impact to a minimum.
Furthermore, surplus energy production should be injected into the electricity grid, providing a sustainable energy source for up to 10,000 homes.
This new paradigm had to be reflected in an equally differentiated approach to the new constructions on the factory site and the architectural goal was to offer an envelope for the entire technical component that goes beyond simple protection from atmospheric agents or noise control, making function evident through form, materiality and colour, in a contemporary and delicate, yet affordable and cheerful way.
The main components were clad, on one axis, with dark grey metal sheet panels in curvilinear shapes that give continuity to the roofs and façades, and, on the other axis, with orange translucent polycarbonate sheeting in the boiler house and precast concrete panels in the noisier volumes of the turbine and fan room.
This highlights the parts of the building where the energy is produced, leaving all the cladding of the auxiliary elements, such as the filters, the ash silo, the chimney or the biomass conveyor, in light grey.
Moreover, the boiler house is internally illuminated at night, further enhancing its role as the core of the energy production process, its iconic status on the industrial site and as a visually warm landmark in the vicinity.
The surrounding paved area for vehicle circulation was reduced to the bare minimum and flanked by two rows of fast-growing trees, framing the building and creating shade.
Regarding the structure design, the unit is essentially steel-framed, with the exception of the turbine body, which was built in reinforced concrete in a prefabrication solution for slabs, beams and columns, fully assembled in about two months.
Paying full attention to all the specific features and functionality that determine the power plant’s operation, the challenge was to evaluate where the whole and the part could be finetuned, adjusted or reshaped, improving former practices and exploring new material, techniques and formal possibilities.
With a very debated and iterative design stage, aiming for a short construction period of about 12 months, the solution saved time and resources, keeping within budget.