The BIOCHARMB project has recently ended, which has developed a biomass pyrolysis plant for the use of biochar in environmental applications.
CETIM have collaborated with the companies Intacta, Acttia (former Gestán Medioambiental), ENSO and Valora.
Galicia is one of the most important forestry powers in Europe, with a wooded area of almost 2,000,000 hectares, which cover more than 64% of its surface. In addition, the Galician forest presents a great development of scrub-type biomass, which covers an area of 634,000 ha, to which must be added the area in which it develops associated with pine and eucalyptus. A better use of this renewable resource constitutes a great opportunity for economic development for Galicia, and in this line Galicia’s Smart Specialization Strategy (RIS3) establishes among its priorities the diversification of technologies and processes related to the use of biomass (Priority 1.3) and the forestry sector, through innovations in processes and products that allow increasing the competitiveness of the so-called Galician Tractor Sectors (Priorities 2.1-2.2).
Seeking to take advantage of these opportunities and aligned with these priorities, BIOCHARMB project has been developed, whose main objective is the development of an alternative way of using forest biomass aimed at obtaining a product with a high value: biochar. To obtain this biochar, a novel pyrolysis has been developed in which the biomass is transformed through a thermal process in the absence of oxygen. On the other hand, for its subsequent use, technologies have been developed for its modification to improve its performance in environmental. applications.
Pyrolysis is a thermal technology for the use of biomass based on an oxidation process between 300 and 1,000 ºC in the absence of oxygen. When pyrolysis is carried out on biomass materials, it gives rise to a solid material rich in carbon called biochar. In the project, a high-efficiency pyrolysis plant has been designed and built, designed to optimize the performance of obtaining biochar and incorporating innovations in its design that allow obtaining an energy-efficient process, with low operating complexity and capable of operating with a wide range of different biomasses. In relation to this last aspect, very satisfactory results have been obtained, being able to process both waste from different types of wood such as: pruning remains, stubble, branches, bark, shredded wood, etc.; and waste of various origin such as manure or sewage sludge.
Water and gas treatment
In collaboration with ENSO Innovation, CETIM has investigated and optimized the use of biochar in water treatment through different processes, both physical and chemical, to modify the properties of biochar, seeking to increase its effectiveness in eliminating a large number of pollutants. such as heavy metals or emerging pollutants.
In parallel, we have worked with Acttia (former Gestán Medioambiental), investigating and optimizing the use of biochar in the treatment of gaseous streams. Different physical, chemical and biological modification methods and a combination of both have been used, which allowed increasing their efficiency in the elimination of different pollutants in landfill gas streams (H2S, NH3, mercaptans, etc.), whose efficiency has been corroborated by the construction and operation of a series of a biofiltration system.
Validation of the research carried out
Validation has been extended for two of BIOCHARMB’s annuities. It has been carried out over long periods of operation – thus identifying maintenance needs and improvements to be implemented in a future commercial-scale plant – in the two pilot plants built during the project – water treatment and gas treatment.
For water treatment technologies validation, effluents of a Wastewater Treatment Plant (WWTP) have been treated, the input and output qualities of the pilot system have been monitored: conventional parameters (such as pH, dissolved oxygen, temperature or conductivity), and the concentration of the selected contaminants in the laboratory stages. The operation of this pilot plant has shown good results for the removal of heavy metals.
For the validation of the air treatment, the gaseous streams of an urban solid waste treatment plant (MSW) have been treated. Hydrogen sulfide (H2S) concentration of, and mainly mercaptans, has been periodically monitored. As the main result of the operation of this pilot plant, it has been shown that biochar shows a complete elimination of odors from the gaseous streams, making it an easily extrapolated solution to other landfills or farms.
These pilot plants have made it possible to validate the operation of the technologies in real operating conditions and have shown very satisfactory and encouraging results with regard to their industrialization. Thus, the BIOCHARMB project has made it possible to develop a highly efficient technology for obtaining biochar and the development of technologies for its application in the treatment of wastewater and gaseous streams.