Air Products and Chemicals, Inc.

The Black Clawson Company

Vincent L Magnotta

Ronald C Naddeo

Paul N Dyer

Konstantinos Hristofas

Robert A Holzl

John Frederick Cirucci

Larry D Markham

Edward F Elton

Robert E Benander

Varin Ayala

Benjamin H Tilley

Pedro M Pita

Danilo S Costa

William Paul Schmidt

Howard P Withers, Jr

Robert E Stevens

Scott A Wallick

Richard E Tressler

Walter T Mullen

Andrew C Martin

Jeffrey Alan Knopf

Virgil G Fox, Jr

Yvonne R DeKay

Walter Thomas Mullen

A process for using ejectors to combine high pressure steam and low pressure oxygen to produce a steam and oxygen enriched gas single phase gas mixture for introduction into various pulp treatments using oxygen with the benefit of low cost compression, low capital requirements and superior oxygen mixing.

Process for the treatment of pulp with oxygen and steam using ejectors

A method for white liquor oxidation in a kraft mill utilizes a two-stage selective oxidation system in which the first stage is operated to remove sulfide while the second stage is operated to oxidize a significant fraction of the remaining oxidizable sulfur compounds to sulfate. The resulting selectively oxidized white liquor products are used as alkali sources for various process steps in the mill. Optionally, white liquor can be oxidized in a single stage to convert a significant fraction of the oxidizable sulfur compounds to sulfate. Methods for controlling the selective oxidation process are disclosed.

Method for producing fully oxidized white liquor

An improved method of chemical recovery from kraft black liquor is disclosed in which the heat generated by controlled oxidation of the liquor is utilized to reduce the viscosity and net heating value of the liquor which allows the firing of a more concentrated liquor in the recovery boiler. Net steam recovery is increased for a given black liquor feed rate. Alternatively, the firing of liquor having a higher solids concentration is possible, which increases the throughput of the recovery boiler.

Method for controlling the viscosity of Kraft black liquor

Method for the treatment of cellulosic pulp in which pulp is distributed upward through a vertical reactor using a unique conical distributor and is discharged using a unique dilution method to eliminate plugging. The system is particularly useful for delignifying virgin wood pulps or decolorizing pulps made from waste paper materials.

Method for distributing cellulosic pulp through a reactor at a constant

Selective white liquor oxidation

A reactor system is disclosed for the treatment of cellulosic pulp in which pulp is distributed upward through a vertical reactor using a unique conical distributor and is discharged using a unique dilution method to eliminate plugging. The system is particularly useful for delignifying virgin wood pulps or decolorizing pulps made from waste paper materials.

Reactor system for treating cellulosic pulp at a constant upward flow

A coated carbon body having improved resistance to high temperature oxidation and a method for producing the coated carbon body are described. The coated carbon body comprises a carbon body, an intermediate glass forming coating within said converted layer, and an outer refractory coating on the intermediate coating. The body has a converted porous layer formed by etching and reacting the body with gaseous boron oxide and the resulting converted layer contains interconnecting interstices and boron carbide formed by the reaction of the boron oxide and the carbon body. The method comprises contacting a carbon body with boron oxide at an elevated temperature sufficient to cause the reaction between the carbon body and boron oxide to form a converted porous layer which contains interconnecting interstices in the body and boron carbide and then applying the intermediate glass forming coating over the converted layer and an outer refractory coating over the intermediate coating.

Oxidation resistant carbon and method for making same

A method is disclosed for the detackification of stickies in the production of recycled paper products containing secondary fibers. Oxygen is used to reduce the tackiness of stickies in secondary pulps, and optionally is used with alkali and/or detackification agents for optimum stickies control.

Oxygen detackification in secondary fiber recovery

Color is removed from secondary pulps with non-chlorine based bleaching agents in treating sequences using oxygen with combinations of peroxide, ozone, and/or hydrosulfite at/controlled pH conditions. Acid treatment prior to bleaching steps improves color removal and protects fibers from damage at more severe bleaching conditions.

Dye stripping by oxygen in secondary fiber recovery

A method for producing a protective coating on the surface of a carbonaceous substrate is described. A substantially uniform coating of a liquid or solid precursor material is provided on the surface of the substrate. The precursor material is one which has boron-oxygen bonds and is substantially non-reactive with the substrate at a first relatively low temperature and is capable of reacting with the substrate at a second temperature which is substantially higher than the first temperature. The substrate is then raised to the second temperature to react the coating with the substrate to form a porous region of substantially uniform depth in the substrate surface. This region contains interconnecting interstices and boron carbide. The interconnecting interstices are then at least partially filled with a glass forming material such as boron, boron oxide, boron carbide, silicon, silicon alloy, silicon dioxide, silicon nitride, silicon oxynitride, germania, and mixtures thereof. A refractory coating may then be deposited on the filled layer. Also described is a coated article produced in accordance with the described method.

Coated carbonaceous articles and method for making same

Dye stripping by oxygen and peroxide in secondary fiber recovery

A coated carbon body having improved resistance to high temperature oxidation and a method for producing the coated carbon body are described. The coated carbon body comprises a carbon body, an intermediate glass forming coating and an outer refractory coating on the intermediate coating. The body has a converted porous layer formed by etching and reacting the body with boron oxide and the resulting converted layer contains interconnecting interstices and boron carbide formed by the reaction of the boron oxide and the carbon body. The method comprises contacting a carbon body with boron oxide at an elevated temperature sufficient to cause the reaction between the carbon body and boron oxide to form a converted porous layer which contains interconnecting interstices in the body and boron carbide and then applying the glass forming coating over the converted layer. Preferably an outer refractory coating is applied over the glass forming coating. The glass forming coating comprises compounds selected from the group consisting of silicon nitride, silicon oxynitride and mixtures thereof. Additionally, both the refractory outer coating and the glass forming coating can contain compounds selected from the group consisting of silicon nitride, silicon oxynitride, and mixtures thereof.

A structural article for high temperature applications comprises a body formed of at least partially consolidated, particulate silicon nitride, a conformal outer coating of silicon nitride or silicon carbide on the body, and a conformal intermediate layer of a silicon, oxygen and nitrogen-containing compound, i.e. silicon oxynitride, chemically bonded to both the body and the outer coating. The method for making such an article comprises providing a body formed of at least partially consolidated, particulate silicon nitride, oxidizing the surface of the body, removing silicon dioxide from the oxidized surface of the body; and chemically vapor depositing a conformal outer coating of silicon nitride or silicon carbide. The conformal outer coating provides a protective envelope around and assists in high temperature isostatic pressing of the body and hence permits one to use the structural article in isostatic pressing processes.

Structral articles

A method is disclosed for the detackification of stickies in the production of recycled paper products containing secondary fibers. Oxygen is used to reduce the tackiness of stickies in secondary pulps, and optionally is used with alkali and/or detackification agents for optimum stickies control. The preferred alkali source is fully oxidized white liquor.

Growing community of inventors

Wescosville, PA, United States of America

Vincent L Magnotta