Cleaner production in the Solvay Process: general strategies and recent developments

The Solvay Process aims at the production of soda ash. The solid and liquid effluents from the soda ash production have been a target of investigation since decades or centuries, often attempting to make use of the wastes. In this paper, all sources of waste from the Solvay Process and their environmental impact are reviewed and possible applications are discussed. It could be shown that, upon disposal into waterways, solid and insoluble wastes have a much higher environmental impact than salt solutions. The results of this study allow the conclusion, that cleaner production in this field can be achieved primarily by the use of cleaner raw materials or by technologies aiming at the avoidance of (solid) wastes or at the increase of the conversion rate of the raw material sodium chloride, whereas the utilization of by-products made from the industrial wastes often faces technical or economical problems.