The Continuous Process of ROSENLEW

No foreign acid is added, the catalyst being a mixture of acetic acid, formic acid, and minor quantities of higher carboxylic acids formed from the raw material. This is called innate catalysis or autocatalysis . In addition to the rather modest hydrogen ion concentration produced by these poorly dissociated carboxylic acids, according to Lowry s general acid catalysis discussed in chapter 3.2, undissociated acid molecules as well as water contribute to the catalysis in these reactors. Apart from this chemical complication, the mass transfer phenomena in the ROSENLEW reactor are intricate as well, for the following reasons  

None of these complications materialize in a system with sulfuric acid as the latter is nonvolatile so that it cannot be stripped out by steam, and as it is so strong that the catalytic contribution by the innate acids is usually negligible, so that the acidity can be considered uniform throughout the charge of the reactor. 

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