Assertion: additional vanillin | /r/AtLocation | said reaction zone
Facets:
Source sentences:
text: maintaining said zone under super-atmospheric pressure, continuously passing a gas containing free gaseous oxygen in finely dispersed form through said reaction zone and continuously removing residual gas, the rate of addition and removal of said gas being such as to maintain a partial pressure of oxygen in said zone of less than 20 lb. per square inch, sodium carbonate being initially present in the material introduced into the reaction zone in an amount equivalent to the calcium content of said solid phase residual, diminished by the calcium present as calcium carbonate in said solid phase residual, and the amount of lime so present being sufiicient to react with the carbonate formed in the reaction, plus an additional amount of lime and sodium carbonate which, in combination, maintain the pH of the reaction mixture (determined on a sample withdrawn from the reaction zone and cooled to room temperature) at not less than 12, the time of said reaction being less than four hours, withdrawing said reaction mixture from said reaction zone, clarifying said reaction mixture by separating the insoluble calcium carbonate from said reaction mixture, acidifying the clarified reaction mixture to precipitate lignin substance, separating said lignin substance therefrom, and extracting the resultant clarified liquor with a solvent to recover vanillin originally present as the calcium derivative of vanillin in said solid phase residual and to recover additional vanillin produced in said reaction zone.