The Reactive Desorption Process

The reactive distillation column was not a distillation column, but a desorption column, as in a distillation column the liquid phase must boil. 

In 27 runs at various conditions, the operators of this pilot plant found to their distress that the furfural yields were only in the order of 30 percent, in harsh contrast to their expectations of 85 percent, derived from calculations based on the known kinetics in water. The designers had made a fundamental mistake They had measured the rate of pentose disappearance in the sulfite liquor, but not the rate of furfural formation, and as the rate of pentose disappearance was far greater than what had to be expected when the liquor s hydrogen ion concentration was used in the known kinetics of xylose disappearance in acid water, they had concluded that the lignosulfonate of the liquor had a special catalytic effect on the pentose-to-furfural conversion. They had overlooked that the fast disappearance of the pentose in the liquor was not due to a mysterious catalysis but caused by loss reactions of the pentose with lignosulfonate and other ingredients of the liquor. 

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