Method of reducing hydrophobic contaminants in a pulping or papermaking process

Abstract

A method of reducing contaminants in a pulp or papermaking process includes the steps of:providing a lignocellulosic pulp comprising lignocellulosic fibers and at least one hydrophobic contaminant;providing a cationic polymer; providing a cleaning blend comprising a vegetable oil alkyl ester and at least one surfactant; andapplying the cationic polymer and the cleaning blend to the lignocellulosic pulp to reduce a content of the at least one hydrophobic contaminant in the pulp or papermaking process.

What is claimed is: 
     
         1 . A method of reducing hydrophobic contaminants in a pulping or papermaking process, said method comprising the steps of:
 providing a lignocellulosic pulp comprising lignocellulosic fibers and at least one hydrophobic contaminant;   providing a cationic polymer;   providing a cleaning blend comprising a vegetable oil alkyl ester and at least one surfactant; and   applying the cationic polymer and the cleaning blend to the lignocellulosic pulp to reduce a content of the at least one hydrophobic contaminant in the pulping or papermaking process.   
     
     
         2 . The method of  claim 1  wherein the cationic polymer is chosen from polydiallyldimethylammonium chloride, polyamines, polyvinylamines, cationic polyacrylamides, copolymers of polydiallyldimethylammonium chloride and acrylic acid, and combinations thereof 
     
     
         3 . The method of  claim 1  wherein the cationic polymer is a cationic polyacrylamide. 
     
     
         4 . The method of  claim 1  wherein the cationic polymer is present in an amount of from about 1 to about 51% weight percent actives based on a total weight of actives of a combination of the cationic polymer and the cleaning blend. 
     
     
         5 . The method of  claim 1  wherein the cleaning blend is present in an amount of from about 1 to about 90 weight percent actives based on a total weight of actives of a combination of the cationic polymer and the cleaning blend. 
     
     
         6 . The method of  claim 1  wherein the vegetable oil alkyl ester is chosen from soybean oil methyl esters, canola (rapeseed) oil methyl esters, corn oil methyl esters, castor oil methyl esters, and combinations thereof. 
     
     
         7 . The method of  claim 1  wherein the cleaning blend further comprises a vegetable oil that is chosen from soybean oil, canola (rapeseed) oil, corn oil, coconut oil, olive oil, palm oil, castor oil, and combinations thereof. 
     
     
         8 . The method of  claim 1  wherein the cleaning blend further comprises a hydrophobic agent chosen from animal oils, mineral oils, silicone oils, terpenes, natural and synthetic aliphatic hydrocarbons, and combinations thereof. 
     
     
         9 . The method of  claim 1  wherein the at least one surfactant is chosen from linear ethoxylated alcohols, branched ethoxylated alcohols, ethoxylated fatty acids, ethoxylated castor oils, ethoxylated sorbitan alcohols, alkyl polyglucosides, ethoxylated glycerides, copolymers of ethylene oxide and propylene oxide, and combinations thereof. 
     
     
         10 . The method of  claim 1  wherein a charge of the cationic polyacrylamide is above about 15 mol % and below about 50 mol %. 
     
     
         11 . The method of  claim 1  wherein the vegetable oil alkyl ester is present in an amount of from about 20 to about 80 wt % actives, the cleaning blend further comprises a vegetable oil that is present in an amount of from greater than about 0 and up to about 20 wt % actives, and the at least one surfactant is present in an amount of from about 20 to about 80 wt % actives, each based on a total weight of actives of the cleaning blend. 
     
     
         12 . The method of  claim 1  wherein a weight ratio of actives of the cationic polymer to actives of the cleaning blend is from about 16:84 to about 50:50. 
     
     
         13 . The method of  claim 1  wherein the step of applying the cationic polymer and the cleaning blend to the lignocellulosic pulp is further defined as applying to the lignocellulosic pulp in a pulp mill. 
     
     
         14 . The method of  claim 1  wherein the step of applying the cationic polymer and the cleaning blend to the lignocellulosic pulp is further defined as applying to the lignocellulosic pulp in a papermaking machine. 
     
     
         15 . The method of  claim 1  wherein the cationic polymer is applied to the lignocellulosic pulp simultaneously with the cleaning blend wherein the cationic polymer and the cleaning blend are not mixed with each other during application. 
     
     
         16 . The method of  claim 1  wherein the cationic polymer is applied to the lignocellulosic pulp simultaneously with the cleaning blend wherein the cationic polymer and the cleaning blend are mixed with each other. 
     
     
         17 . The method of  claim 1  wherein the cationic polymer is applied to the lignocellulosic pulp at a different time than the cleaning blend. 
     
     
         18 . The method of  claim 17  wherein the cationic polymer is applied prior to the cleaning blend. 
     
     
         19 . The method of  claim 17  wherein the cationic polymer is applied subsequent to the cleaning blend. 
     
     
         20 . The method of  claim 1  wherein the cleaning blend further comprises a vegetable oil.