Panu Tikka re-visited another 90’s SciTech-Service patent: “Process for the production of a hemicellulose hydrolysate and special high alpha cellulose pulp”.
Panu Tikka comments on the invention and explains how the process started and evolved:
Scitech was asked by a specialty chemical company for developing a process producing MCC (micro-crystalline cellulose) and/or dissolving pulp and xylose (for xylitol) from birch wood. Earlier, xylose was produced by direct harsh hydrolysis of wood with bad economy. After experimenting a variety of pre-hydrolysis-cooking processes it appeared that it was possible to combine pre-hydrolysis of xylose with neutralsulfite-AQ-cooking method. Quite unexpectedly the NS-AQ-process performed much better after the pre-hydrolysis and pure cellulose could be produced with xylose-prehydrolysate as the by-product. A patent was applied and granted. The original ordering company gave up interest to use wood as raw material and the patent rights returned to inventors. Later rights were licensed to a major pulp & paper company, after a few intensive years of studies and planning the company withdrew from plans to invest a new big specialty pulp mill. Nonetheless, this was a breakthrough in the field of combining acidic pre-treatment and mildly alkaline cooking.