IMPROVEMENTS IN WASTE MINIMIZATION, PROCESS SAFETY, AND RUNNING COSTSBY INTEGRATED PROCESS-DEVELOPMENT

By the development of a new recycling process for spent acid in the ma nufacture of the 1-chloro-2,4-dinitrobenzene (CDNB) effective improvem ents in the waste balance and the process safety were achieved. Under the old process, the sulfuric acid generated could not be sold to the low strength sulfuric-acid market, because it had a high concentration of organic contaminants. The resulting waste stream had long been a c ostly issue. A laboratory feasibility study followed by pilot evaluati on qualified continuous extraction as an appropriate technology for pu rifying the acid. With the change from a batch extraction process to a continuous extraction on a column, the quality of the acid could be i mproved such that use without further regeneration is possible now. Th us, the continuous extraction column offered improved efficiency, safe ty, and product consistency as compared to the corresponding batch pro cess.