Improvement of Resource Efficiency and Environmental Performance in Clay Brick Industry
 

The clay brick production industry is a major source of air pollution in developing countries. The major issues in environmental improvement involve improving the combustion efficiency of existing kilns, and upgrading kilns to newer and more efficient process designs. Most of the cleaner production effort has been in China, where a number of studies and improvement projects have been conducted. The amount of information on the web about CP in this industry is relatively low. Process technology upgrades are usually capital intensive in this industry. Combustion efficiency improvements can be achieved with relatively low costs in many kilns. Promoting cleaner production in this industry requires extensive understanding of and work with the brickmaking community because there are many social and economic factors affecting potential technology changes.

The following below lists several low-cost ways to reduce waste and pollution in brick making. 

Solid fuel is mixed with the bricks throughout the kiln, either as sawdust mixed into the brick mass or as fuel channels in different levels of the kiln. By doing this, a combustion zone can be generated in the kiln that gradually moves upwards, using the residual heat in the lower, already burnt bricks for preheating of combustion air. The residual heat in the flue gasses is used for drying and preheating of the higher levels of crude bricks.

Extended drying time reduces fuel requirements. Even drying throughout brick stacks reduces defective firing of bricks. Stopping all air leaks and controlling the kiln opening size allows better control of air flow speed and direction to improve combustion. If available and competitively priced, these fuels have significantly less emissions and can increase production quality and speed.

Vertical shaft brick kilns allow increased production rates and significantly decreased emissions through improved combustion air flow efficiency. Several other kiln designs have also proven to be relatively low-cost and much more efficient than traditional ovens or kilns.