Abstract: The present invention is a cryogenic subterranean fracturing fluid, comprising a liquefied industrial gas and a viscosity increasing additive. The liquefied industrial gas may be liquefied carbon dioxide, liquefied nitrogen, or a blend of the two. The liquefied industrial gas mixture should be substantially free of water. In this context, substantially free of water means less than 10% water by volume, or preferably less than 5% water by volume. In addition to the viscosity increasing additive, a proppant may be added to the fracturing fluid. In addition to the viscosity increasing additive and/or proppant additional additives may be added to the liquefied industrial gas as required.

Abstract: The present invention is a cryogenic subterranean fracturing fluid, comprising a liquefied industrial gas and a viscosity increasing additive. The liquefied industrial gas may be liquefied carbon dioxide, liquefied nitrogen, or a blend of the two. The liquefied industrial gas mixture should be substantially free of water. In this context, substantially free of water means less than 10% water by volume, or preferably less than 5% water by volume. In addition to the viscosity increasing additive, a proppant may be added to the fracturing fluid. In addition to the viscosity increasing additive and/or proppant additional additives may be added to the liquefied industrial gas as required.

Abstract: The present invention is a cryogenic subterranean fracturing fluid, comprising a liquefied industrial gas and a first additive. The liquefied industrial gas may be liquefied carbon dioxide, liquefied nitrogen, or a blend of the two. The liquefied industrial gas mixture should be substantially free of water. In this context, substantially free of water means less than 10% water by volume, or preferably less than 5% water by volume. In addition to the first additive, a proppant may be added to the fracturing fluid. In addition to the biocide and/or proppant additional additives may be added to the liquefied industrial gas as required. Non-limiting examples of such additives include ozone, a friction reducer, an acid, a gelling agent, a breaker, a scale inhibitor, a clay stabilizer, a corrosion inhibitor, an iron controller, an oxygen scavenger, a surfactant, a cross-linker, a non-emulsifier, a Ph Adjusting agent, or any combination thereof.

Abstract: The present invention provides a process for preparing polysulfide. More particularly, the process of the present invention allows one to prepare the amount of polysulfide needed using clarified white liquor, and to be used when and where it is needed during the cooking process. The process comprises reacting alkaline digesting liquor after clarification with a catalytic amount of a transition metal oxide catalyst, most preferably manganese dioxide. The reaction is conducted at a temperature of 98° C. or less, and is conducted for a short period of time, e.g., less than five minutes, with no oxygen gas or air being introduced with the catalyst and the main flow of clarified liquor.

Abstract: A cleaning method for removing solid deposits of the oxides of nitrogen, especially dinitrogen pentoxide, from ozone generator tubes and dielectrics is described. The method circulates warm dry gas in the tube section of the generator, warm water in the shell section or both to clean the ozone generator. The oxides are evaporated and evacuated from the system. The method substantially reduces or eliminates the formation of nitric acid on the tubes and dielectrics when the generator is exposed to humidity upon being opened to the atmosphere.

Abstract: A system and method for generating polysulfide includes at least one vessel for containing the pulping liquor, and at least one oxidation promoter element including an oxidation promoter adhered by a coating material to a substrate. The oxidation promoter element may be affixed within the vessel or, alternatively, movable between two or more vessels to facilitate polysulfide generation and/or recovery of the oxidation promoter in at least two vessels.

Abstract: The present invention provides a process for preparing polysulfide. More particularly, the process of the present invention allows one to prepare the amount of polysulfide needed using clarified white liquor, and to be used when and where it is needed during the cooking process. The process comprises reacting alkaline digesting liquor after clarification with a catalytic amount of a transition metal oxide catalyst, most preferably manganese dioxide. The reaction is conducted at a temperature of 98° C. or less, and is conducted for a short period of time, e.g., less than five minutes, with no oxygen gas or air being introduced with the catalyst and the main flow of clarified liquor.

Abstract: A cleaning method for removing solid deposits of the oxides of nitrogen, especially dinitrogen pentoxide, from ozone generator tubes and dielectrics is described. The method circulates warm dry gas in the tube section of the generator, warm water in the shell section or both to clean the ozone generator. The oxides are evaporated and evacuated from the system. The method substantially reduces or eliminates the formation of nitric acid on the tubes and dielectrics when the generator is exposed to humidity upon being opened to the atmosphere.

Abstract: A method of bleaching a pulp at low consistency employs chlorine dioxide and/or chlorine, to partially bleach the pulp. The aqueous partially bleached pulp flows along a sinuous flow path providing a high ratio of flow path of aqueous pulp to length of effective travel of the aqueous pulp. Ozone is introduced to the aqueous pulp at spaced apart locations in the flow path so that a low partial pressure of ozone is established in the flow path which favors chemical oxidation of the lignin and low chemical attack on cellulose. In this way effective bleaching is achieved with reduced use of chlorine or chlorine dioxide and reduced production of chlorinated compounds.