Alkaline pulping using gaseous oxygen

Claim 1

IN THE PROCESS FOR THE PRODUCTION OF SUBSTANTIALLY LIGNIN-FREE HOLOCELLULOSE FROM CELLULOSIC RAW MATERIAL BY PULPING THE MATERIAL, UNDER PRESSURE, WITH ALKALINE SOLUTION AND IN THE PRESENCE OF AN OXIDIZING MATERIAL AT ELEVATED TEMPERATURE, THE IMPROVEMENT COMPRISING PULPING THE SAID MATERIAL WITH AN ALKALINE SOLUTION OF AT LEAST ONE MATERIAL OF THE GROUP CONSISTING OF SODIUM BICARBONATE, SODIUM TETRABORATE, SODIUM BENZOATE SODIUM HYDROSULFIDE, SODIUM PHENOLATE, SODIUM ACID TELLURATE, AND SODIUM MONOHYDROGEN ORTHOPHOSPHATE AT A TEMPERATURE BETWEEN 125* AND 175* C. FOR A PERIOD FROM ABOUT 2 TO ABOUT 5 HOURS IN THE PRESENCE OF AT LEAST ONE OXIDIZING MATERIAL OF THE GROUP CONSISTING OF SUBSTANTIALLY PURE OXYGEN AND AIR HAVING A PARTIAL OXYGEN PRESSURE OF AT LEAST 800 POUNDS PER SQUARE INCH WHILE MAINTAINING THE ALKALINE SOLUTION AT A PH OF BETWEEN 7 AND 9 THROUGHOUT SAID PULPING, WHEREBY A HIGH YIELD OF THE SUBSTANTIALLY LIGNIN-FREE HOLOCELLULOSE IS OBTAINED AND THE LIGNIN AND RESINS RECOVERED FROM SAID SOLUTION HAVE LOW MOLECULAR WEIGHT AND GOOD SOLUBILITY CHARACTERISTICS.