American Air Liquide, Inc.

Canadian Liquid Air Ltd - Air Liquidecanada Ltee

Air Liquide Canada, Inc.

Michel Epiney

Meenakshi V Sundaram

Derek Hornsey

Vasuhi Rasanayagam

Sebastien Corbeil

John R Ayton

Gordon H Homer

Camille Lanctot-Downs

Fabrice Laberge

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.

Hydraulic fracturing with improved viscosity liquefied industrial gas based solution

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&#xb0; 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.

Process for preparing polysulfides using clarified white liquor

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.

Method for ozone bleaching of cellulosic pulp at low consistency

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Duvernay, Canada

Michel Epiney