Researchers at the University of Alicante produce good-quality activated carbon from hemp waste

Researchers at the University of Alicante have just proved that good-quality activated carbon can be obtained from hemp residue, which is used as a filter for water treatment and the elimination of polluting gases in industry. This innovation is part of the CARVOC Project: Innovative Eco-Friendly Activated Carbon Filters for Harmful Vapours & Gases VOC Purification", in which Spain, France and the UK were involved with funding from the European Commission.

The project began in March 2013 and now the results have proved the production of good-quality activated carbon from the hemp residue, as stated by Director of UA Research Group in Carbon Materials and Environment and Project Manager Diego Cazorla. "This material can be used in diverse sectors such as water purification, pharmaceutical and textile industries" he adds.

Activated carbon has the ability to attract and filter gases, vapours, liquids and dissolved substances on its surface, this is why its production and consumption has increased in recent years. This demand is mainly focused on water treatment plants as they need tons of this material for their functioning.

Carbon new refuse processing

UA researcher explains the main problem "lies in the high economic cost of disposing used activated carbon and its subsequent handling and management, given its highly polluting nature".

In this sense, one of the techniques used for the treatment is thermal regeneration although it has several drawbacks: the active carbon used needs to be moved to the regeneration centre and then brought back to the place where it is to be used. Also, the energy cost is high as it requires high temperatures (600-1000 degrees C), around five and twenty percent of activated carbon is lost during the combustion process causing environmental problems due to high energy consumption, transport and the release of greenhouse gases in the recovery phase.

In order to overcome these limitations, Cazorla and Professor Emilia Morallón, from the UA Institute of Materials, have patented a new technology that is — as they say — "efficient, sustainable and cheaper" compared to the existing ones: electrochemical regeneration.

The system uses electric current that can be delivered by a conventional power supply or directly from any system based on renewable energies such as solar or wind turbine devices and, thus, the regeneration of activated carbon can be in the same place where it is being used and with a much lower energy consumption.