Abstract: A procedure for determining the composition of a wood chip mix dispensed in alkaline delignifying processes, particularly in sulphate and soda/anthraquinone cooking, with the aid of the monomeric compounds produced in connection with the cooking and dissolved in the waste liquor. As taught by the procedure, a cooking liquor sample is taken in the cooking process, this sample being chromatographically analyzed. On the basis of the content proportions of certain compounds analyzed by substance groups, the composition of the dispensed wood chip mix is determined, and at the same time information is gained for optimating the conditions applied in the cooking process.

Abstract: A procedure for monitoring alkaline delignification, in particular kraft cooking, of wood or other cellulosic material with the aid of the mutually relative concentrations of the monomeric lignin hydration products which are formed in connection therewith and are dissolved in the spent liquor. According to the procedure, a sufficient number of representative spent liquor samples is taken during the cooking process which are analyzed by gas chromatography. On the basis of the concentration proportions of certain compounds which have been analyzed, that time period is determined in each instance which is required to reach the desired degree of delignification.