The potential for chrome tanning waste to be used as an inexpensive and environmentally-compatible fuel has been highlighted in a new Brazilian research paper.

Published by Engineer Leandro Dalla Zen, co-ordinator of the Combustion Laboratory of Cientec - Science and Technology Foundation, Porto Alegre/RS, the paper is the outcome of six year’s research into the ‘fluid bed’ combustion process, where duly prepared solid waste is combusted while suspended in fluid.

"The process has a number of environmental and commercial advantages," Dalla Zen explains. "As well as providing an efficient mechanism for removing waste from the environment, it also cuts down on the use of firewood and other non-renewable resources as a fuel. It also raises the possibility of generating extra revenue through the sale of the ashes, which possess excellent anti-corrosion properties."

According to Dalla Zen, the process conforms to all but one of the emission parameters set down by Brazilian environmental legislation – the exception being its sulphur dioxide output which is 20% higher than permitted levels. However, this can easily be rectified by burning the fuel in conjunction with wood, the exact proportions of which Dalla Zen was still working out.

Although the process has been designed with the needs of individual tanneries in mind, Dalla Zen says it could easily be scaled up to provide large shared facilities for tannery clusters.  In either instance, the energy produced could be used to generate steam and/or electricity, with the  ashes being used in the production of fireproof materials or as a corrosion inhibitor in concrete, for applications such as sea platforms and underwater pillars.