Here is the first published article on the topic of Pass-through Distillation, by Anton Kiss et al. It was published in the European journal NPT Process Technology in 2014. Please click to view.
Here is an academic thesis applying Aspen Plus modelling to PTD. The author is Haley Hayden Smestad. The academic institution was Worcester Polytechnic Institute.
Here is another academic paper from the Polytechnic University of Bucharest. The treatment of Pass-through Distillation begins on page 7.
Here is an Abstract of an important article
Rapid ethanol fermentations using vacuum and cell recycle
Cell recycle and vacuum fermentation systems were developed for continuous ethanol production. Cell recycle was employed in both atmospheric pressure and vacuum fermentations to achieve high cell densities and rapid ethanol fermentation rates. Studies were conducted with Saccharomyces cerevisiae (ATCC No. 4126) at a fermentation temperature of 35°C. Employing a 10% glucose feed, a cell density of 50 g dry wt/liter was obtained in atmospheric‐cell recycle fermentations which produced a fermentor ethanol productivity of 29.0 g/liter‐hr. The vacuum fermentor eliminated ethanol inhibition by boiling away ethanol from the fermenting beer as it was formed. This permitted the rapid and complete fermentation of concentrated sugar solutions. At a total pressure of 50 mmHg and using a 33.4% glucose feed, ethanol productivities of 82 and 40 g/liter‐hr were achieved with the vacuum system with and without cell recycle, respectively. Fermentor ethanol productivities were thus increased as much as twelvefold over conventional continuous fermentations. In order to maintain a viable yeast culture in the vacuum fermentor, a bleed of fermented broth had to be continuously withdrawn to remove nonvolatile compounds. It was also necessary to sparge the vacuum fermentor with pure oxygen to satisfy the trace oxygen requirement of the fermenting yeast.