Noram Engineering and Constructors Ltd.

Pulp and Paper Research Institute of Canada

University of Missouri

Huntsman International LLC

James Theodore Wearing

Jonathan Edward Foan

Richard M Berry

Michael Paleologou

Colin W Oloman

Brian Robin Blackwell

Arend-Jan Zeeuw

Rokhsareh Thompson

Clive Brereton

Robert M Hogikyan

David Anthony Boyd

James M Lockhart

Robert W Murray

Jianxin Chen

Durk Devries

Evan J Hobenshield

Kenneth Hunt

Ali Gulamhusein

Chung-Li Lee

Rohan Bandekar

Processes and systems for treating Kraft pulping foul condensate are provided. The processes comprise removing volatile compounds from the foul condensate to produce a resulting condensate and removing methanol from the resulting condensate. The systems comprise a volatile compound removal stage and a methanol removal stage downstream of and in fluid communication with the volatile removal stage.

Kraft pulping foul condensate treatment process and apparatus

A method and apparatus for contacting and reacting fine cellulosic material with acid to produce partly-hydrolyzed cellulose, in which the cellulose is compressed to form higher density material, resulting in reduced consumption of acid and increased uniformity of reaction times. Cellulosic material, such as ground wood pulp, is compressed to reduce the interstitial spaces therein. The compressed material is contacted with an acid, such as sulfuric acid, which is allowed to wick into the interstitial spaces and react with the cellulose to produce partly-hydrolyzed cellulose.

Process for making partly-hydrolyzed cellulose using compressed cellulosic materials

The invention discloses a process for treating black liquor comprising pyrolyzing black liquor in a fluidized bed reactor to obtain solid particles and pyrolyzed black liquor gas, heating the solid mass, returning the heated solid mass to the fluidized bed reactor for use in the pyrolysis reaction; condensing the pyrolyzed black liquor gas to obtain a condensate and recover heat and a residual gas released during condensation for heating the solid mass to a predetermined temperature for that is required for the pyrolysis.

Process for treating black liquor

Methods and apparatus for maintaining sulfur concentration in the chemical recovery cycle of a Kraft pulping process. A portion of the recovery boiler ash is dissolved, treated to remove solids, and combined with an acid to provide a solution. The recovery boiler ash may be dissolved directly in the acid. The acid may be effluent from a chlorine dioxide generator. The resulting solution is maintained in a fully dissolved state and subjected to an acid separation step to provide a sodium sulfate enriched phase, which may be used to maintain sulfur concentration in the Kraft pulping process, and a sulfuric acid phase. Chlorine ions can be separated with the sulfuric acid phase. The sulfuric acid phase can be recycled to the chlorine dioxide generator.

Maintenance of sulfur concentration in Kraft pulp processes

A process for the recovery of alkali metal hydroxide and acid from the alkali metal salts of monovalent anions which are mixed with the alkali metal salts of multivalent anions employs a water-splitting system composed of bipolar membranes in conjunction with ion-selective membranes; a two-compartment cell employs monovalent anion-selective membranes to define salt/base and acid compartments with the bipolar membranes, and a three-compartment cell employs, monovalent anion-selective and cation-selective membranes to define with the bipolar membranes, acid, salt and base compartments; the process has particular applicability to the conversion of the sodium/potassium chloride portion of the Electrostatic Precipitator (ESP) Catch of the recovery boiler of coastal and/or closed-cycle kraft pulp mills, a mixture of mostly sodium/potassium sulphate and chloride, into sodium/potassium hydroxide and hydrochloric acid; the remaining sodium/potassium sulphate solution, depleted in chloride, can thus be used as sodium/sulphur make-up to the recovery cycle or converted to sulphuric acid and sodium/potassium hydroxide; a simpler version of the process, can be employed for the electrodialytic separation of ESP catch into its component sodium chloride and sodium sulphate; when a three-compartment water-splitting or electrodialysis system is used, potassium ions are preferentially removed from the feed compartment, over sodium, thus removing this undesirable non-process element from the alkali metal sulphate portion which is returned to the recovery cycle; there is also described approaches through which a partially or totally effluent free (TEF) kraft pulp mill can be achieved in terms of the elements sodium, sulphur and chlorine.

Electromembrane processes for the treatment of kraft mill electrostatic

A chemical pulp which contains reactants capable of generating dioxirane within the pulp is produced in a process which comprises mixing a pulp with reactants comprising a carbonyl compound, preferably acetone, and an oxygen donor, preferably monoperoxysulfate, in proportions which produce a water-soluble dioxirane having a molecular diameter of less than 140 angstrom units. Such a pulp bleaching process which employs dioxirane as a bleaching agent is rendered environmentally and economically acceptable by recycling the reactants employed to produce the dioxirane.

Bleaching of lignocellulosic material with in-situ-generated dioxirane

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Vancouver, Canada

James Theodore Wearing