US EPA

1442350 

Journal Article 

THE BENEFITS OF PROCESS INTENSIFICATION FOR CARO ACID PRODUCTION 

Whiting, MJL 

1992 

Yes 

Chemical Engineering Research and Design
ISSN: 0263-8762
EISSN: 1744-3563 

70 

2 

195-196 

WOS:A1992HP92000019 

Process intensification is a method of achieving inherently
safer designs by reducing the inventory of hazardous material. Fortuitously, intensification also
reduces capital cost because if less material is present, then vessels pipes, structures and
foundations become smaller and cheaper. Traditionally, Caro's acid has been produced by reacting
concentrated sulphuric acid with hydrogen peroxide at sub-ambient temperatures to avoid product
decomposition. The equipment was bulky and relatively costly-typically a refrigerated 30 litre
reactor vessel operating with a residence time of 30 minutes was needed to produce 300 kg per day
of product. The high capital and operating costs of such equipment greatly limited the in situ
generation of Caro's acid for use as an oxidant for potential applications. However, by applying
the principle of intensification Interox have developed a continuous adiabatic reactor with an
output three times greater than the previous unit, using a reactor volume of only 20 ml
(equivalent to a size reduction of 1500:1), a residence time of less than a second and capable of
operating without cooling. A unit has successfully completed field trials extracting uranium in
Australia and detoxifying a cyanide effluent in Europe. On the basis of this work, a compact,
portable, stand-alone Caro's acid generator has been built which is designed to run
automatically without constant supervision at user sites around the world. The development of the
unit has demonstrated that a simpler and safer design can be achieved by process intensification
with significant savings in both capital and operating costs.