Researchers at Jaen University in Spain have mixed paper industry waste with a ceramic material used in the construction industry to create a brick with low thermal conductivity. ‘Adding waste means that the end product has low thermal conductivity and is therefore a good insulator, in addition to the resulting benefit of using these bricks instead of their traditional counterparts made of traditional raw materials,’ said Carmen Martínez, a researcher at the university. The scientists, whose research is published in the journal Fuel Processing Technology, collected cellulous waste from a paper factory along with sludge from the purification of its wastewater. They then mixed this material with clay used in construction and passed the mixture through a pressure and extrusion machine to obtain bricks. Another advantage of adding waste to the brick prototypes is that they provide energy because of their organic material content.
This helps to reduce fuel consumption and kiln time required for brick production. Apart from the use of waste materials, the eco friendly bricks need less firing time when compared with conventional bricks and hence save a lot of energy and reduces production cost. Additionally, since the bricks make use of paper, they offer low thermal conductivity and offer great insulation properties if used in a building. The team states that the mechanical resistance of bricks isn’t that great, although it’s still above the legal minimum. The team hopes to fine-tune the design a little and include some more waste products from beer and biodiesel industries to cope up with the mechanical strength issue. The prototype’s dimensions are currently 3 x 1 x 6cm but the team has already tested larger bricks and the results are said to be similar. In Fuel Processing Technology, the researchers have published another study confirming that biodiesel waste can be used for brick manufacture, increasing insulation capacity by 40 per cent. The team is continuing its search for a compromise between sustainability and material resistance.