122results about "Pulp gases treatment" patented technology

The invention relates to a process of detoxifying pretreated lignocellulose-containing material comprising washing the pretreated lignocellulose-containing material in a washing solution and treating the used washing solution to remove an enzyme inhibitor and/or an inhibitor of a fermenting organism before recycling the used washing solution.

A method is provided for treating black liquor particularly derived from non-wood pulp, by heating with an alkaline earth metal oxide in a toroidal fluidised bed reactor at a temperature of above 650° C. The method may be used alone or as part of a method of converting graminaceous raw material to pulp for paper or board, said method comprising (a) digesting said raw material with a white liquor based on sodium hydroxide and further comprising calcium hydroxide in an amount effective to substantially convert silica of said raw material to calcium silicate; (b) recovering pulp and black liquor substantially free of uncombined silica; (c) heating the black liquor in a fluidized bed reactor containing calcium oxide for catalysing conversion of organic content of said black liquor to gas and for providing recovered solids including sodium values of said white liquor and calcium oxide; and regenerating said white liquor using said recovered solids. The use of the above mentioned white liquor permits treatment of wheat straw, rice straw and other high-silica materials without resulting in a black liquor that is difficult to treat.

The invention relates to a process system and a method for preliminary treatment of disintegrated cellulose-containing material, preferably wood chips, prior to pulp digestion. The process system and the method according to the invention make use of a process vessel intended to function both as a so-called chip bin and as a pre-impregnation vessel. The characteristics of the invention are that a sloping steaming vessel is arranged downstream of the process vessel for the purpose of separating an excess of pre-impregnation liquid from the pre-impregnated cellulose-containing material, that the sloping steaming vessel is arranged for supplying steaming vapor which preferably has been generated by flashing of extraction liquor from a pulp digester, and that the sloping steaming vessel is connected to a chip chute communicating with a condenser for connection to a system for managing foul-smelling process gases. The invention can be applied in the production of pulp which is intended for paper manufacture or other applications where cellulose fibers are used.

An apparatus for feeding one or more chemicals into a process stream of a papermaking process is disclosed, as well as a method of utilizing the apparatus for feeding one or more chemicals into a process stream is disclosed.

A method in connection with the production of mechanical pulp from a cellulose containing material wherein the material is processed in at least one refining step to produce pulp. According to the invention, the pulp is fractionated (4), after a first refining step (1), in order to separate primary fines (5) from the pulp. The invention also relates to a mechanical pulp, produced by the method, and to a paperboard, which at least partly consists of such mechanical pulp.

The invention relates to a method and apparatus to recover and purify methanol from gases produced in the digester during the kraft pulping process. The gas is typically recovered as a foul gas (called stripper off gas or SOG) comprising methanol, water and various other contaminants. The gas is then treated with successive decanting and distillation steps to remove impurities, thereby producing highly purified methanol.

A method for generating steam in a digester plant of a chemical pulp mill including: producing black liquor in the digester plant, extracting a first stream of black liquor from the digester; generating vapor by evaporating the first stream of black liquor by heating the first stream with fresh steam; heating fibrous material in the digester with the generated vapor from the evaporated first stream of black liquor; extracting a second stream of black liquor from the digester; flashing the second stream of black liquor to generate flashed black liquor and flashed black liquor vapor; introducing the flashed black liquor vapor to at least one heat exchanger to indirectly heat a clean evaporable liquid to produce clean steam from the clean evaporable liquid; and steaming, with the clean steam produced in the at least one heat ex-changer, cellulosic feed material before feeding the cellulosic feed material to the digester plant.

A selective removal of metal and its anion species that are detrimental to subsequent hydrothermal hydrocatalytic conversion from the biomass feed prior to carrying out catalytic hydrogenation/hydrogenolysis/hydrodeoxygenation of the biomass in a manner that does not reduce the effectiveness of the hydrothermal hydrocatalytic treatment while minimizing the amount of water used in the process is provided.

A vapor relief strainer cleaning assembly comprising a turbine and dislodger assembly, wherein the turbine is configured to move a dislodger assembly disposed within a vapor screen relief vessel. Exemplary dislodger assemblies are configured to be powered by vapor or gas and to use excess vapor or gas optionally to dislodge non-condensable contaminants from the filter screen or to facilitate contaminant dislodgement from the inner wall of the filter screen.

A method for the continuous cooking of chemical pulp with the aim of achieving improved heat economy in a digester system having a vessel (1) for impregnation and a vessel (2) for cooking the impregnated cellulose chips. A part of the black liquor (14) withdrawn from the digester (2) is added at the beginning of a transfer system (4) to increase the temperature of the chips mixture in the transfer system (4). A fraction of the transport fluid (10) from the transfer system (4) that is continuously withdrawn from the impregnated chips fed into the top of the digester is returned to the impregnation vessel (1) at essentially the maintained transfer temperature.

The present invention relates to wastewater treatment in general and to methods of controlling odors and degrading compounds contained in wastewater in particular.

In a method for processing flue gases, flue gases from an incineration plant for non-condensable gases of a kraft pulp mill are scrubbed by means of a calcium compound. The calcium compound is lime mud taken from the chemical recirculation of the kraft pulp mill after causticization and before a lime reburning kiln, and it is used in the scrubbing of gas as a substance reacting with sulphur dioxide.

Desirable chemicals are recovered from a raw material that is formed in substantial amounts during the production of cellulose pulp from renewable lingo-cellulose material. An ammonia/ammonium-containing methanol/water mixture is acidified with an acid that has the ability of forming ammonium salt with the ammonium. The mixture is circulated and passed through an apparatus that has an indirect heat exchanger combined with an storage volume fitted with a gas collection device.

A spent liquor recovery boiler in the pulp and paper industry including a water/steam circulation system having superheaters, the circulation system connected to a steam turbine comprising a high-pressure part, and a furnace for burning spent liquor to produce flue gases, and including an upper portion through which the flue gases flow, wherein the steam/water circulation system of the recovery boiler is provided with a reheater for reheating steam from the high-pressure part of the turbine.

A method wherein a methanol-containing waste gas stream, such as a pulp mill waste stream which contains methanol and other waste products, including methyl mercaptans, is passed in contact with a catalyst comprising a supported or unsupported bulk metal oxide catalyst in the presence of an oxidizing agent; preferably the gas stream is contacted with the catalyst, in the presence of the oxidizing agent, for a time sufficient to convert at least a portion of the methanol to formaldehyde (CH2O).

In a tall oil refining operating plant, a warm water loop is disclosed for cooling the tall oil heads fraction extracted from the crude tall oil, rather than the conventional use of cold water. This avoids condensation and the subsequent solidification of athraquinone pulping aid remaining in the crude tall oil; thus, avoiding fouling of the cooling towers. The temperature of the warm-water is controlled automatically by tempering the cold water entering the warm water "cooling" loop, while removing excessively warm water from said loop to the cooling tower system, as needed.