The latest addition to Dr. Ragauskas’ laboratory is a modified kraft (M/K) digester, which is capable of simulating almost any modified Kraft cooking process.   The digester system permits sampling and adjustment of pulping liquors while cooking is in progress.  This capability, coupled with computer-assisted procedures for rapid liquor analysis and adjustment, allows the M/K digester system to simulate a variety of biorefining pretreatment protocols and modern cooking technologies used in Kraft pulp mills.

Digester features include a pair of 10-liter circulated vessels with a liquor injector, a rapid circulating and mixing system, and precise temperature and pressure controls. The dual vessel system enables the user to generate steam or to preheat liquor in one vessel for use in cooking in the other vessel.  A temperature sensor capable of measuring to a one-tenth of a degree Celsius accuracy is located directly in the flow stream of liquor for optimum temperature sensing.