A team of scientists from the Faculty of Science and Technology, University of Coimbra (FCTUC) has developed, in partnership with industry, an innovative technological system of energy cogeneration from biomass for customers with large thermal and electrical energy consumptions, in the service, small and medium industry and agricultural sectors.

Energy cogeneration consists in the simultaneous production of two forms of energy – in this case, thermal and electrical – by burning a single fuel, fossil or not, and is characterized as being more economical, efficient, and sustainable than traditional methods of independent generation.

The energy cogeneration technology developed by FCTUC scientists, within the scope of projects developed with SCIVEN, Lda in recent years, is materialized in a modular equipment coupled to a boiler for hot water production, preferably, but not necessarily powered by biomass. The new system thus becomes a mini-plant for local electricity production, more efficient and sustainable compared to large plants, whenever its user needs thermal energy. Basically, explain the project coordinators, José Baranda Ribeiro, Jorge André and Ricardo Mendes, from the Mechanical Engineering Department at FCTUC, and Eduardo Costa, from the company SCIVEN, “from a biomass boiler, we developed a set of technology capable of producing electricity for self-consumption while heating water or spaces. We chose to integrate in the pilot system a biomass boiler, in this case pellets [pellets from sustainably produced wood waste], because they are a renewable, clean, reliable, and certified quality energy source, besides being economically very competitive.

In addition, the latest generation biomass boilers, such as those operated by SCIVEN, are of transparent, convenient, safe and reliable operation and maintenance for the user, and are suitable for the most demanding markets, such as services.

Currently, the most commonly used boilers, for example, in hotels, private institutions, and public buildings (hospitals, universities, airports, etc.), are gas (natural or propane) or diesel boilers, which are much more expensive fuels than pellets delivered on site. For this reason, their substitution by this integrated system “will be highly advantageous for industries and services that need both heat and electricity, both from an economic and environmental point of view. It is a solution that significantly reduces energy costs. It is also aligned with the goals of decarbonization of processes and the economy, with a potential reduction of CO2 emissions in the order of hundreds of tons per year. It is, therefore, a particularly suitable solution for small and medium-sized facilities with high levels of thermal energy consumption,” say the promoters.

The coordinators also note that the large-scale implementation of this type of system in Portugal “not only allows for a reduction in the import of fossil fuels, contributing to a sustainable energy policy, but also contributes to the creation of new value chains. For example, it encourages better forest management, valuing the waste resulting from the cleaning of forests and reducing the risk of forest fires, through local networks of collection, processing and consumption of biomass. Thus, the valorization of endogenous natural resources and the settlement of people in areas predominantly disadvantaged by rurality and interiority is encouraged”.

According to the FCTUC scientists, the great innovation of this project “is to prove the viability of mini energy cogeneration, that is, the cogeneration of energy on a small scale, given that cogeneration for large powers has already been practiced for many years. The aim of the project is to create economic value through an integrated heat and power cogeneration system incorporating a biomass boiler.”

The mini pilot plant built at full scale, installed at the Mechanical Engineering Department of the FCTUC, is characterized by a nominal thermal power of 350 kW and a nominal electric power of 12 kW. This technological system was developed within the scope of a project funded by the PT2020 program and by national funds through the National Agency for Innovation. The consortium will continue the development of the technology in order to expand its market.