Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Including recovery of organic by-product
Patent
1984-03-20
1987-05-26
Alvo, Steve
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Including recovery of organic by-product
162 19, 162 39, 162 71, 162 82, 127 37, D21C 104, D21C 302, D21C 326
Patent
active
046683402
ABSTRACT:
A method and apparatus are provided for the treatment of comminuted cellulosic fibrous material to effect prehydrolysis, and then subsequently kraft digestion, thereof, to produce paper pulp. The material is steamed, entrained in liquid to form a suspension, and transferred by a high pressure feeder in a first circulation loop to the top of a first vertical vessel. At the top of the vessel, a liquid/solids separator is provided, and the liquid withdrawn from the top of the first vessel into the return conduit of the first circulation loop includes recoverable hydrolysate (which contains hemicellulose, sugars, and the like). In the first vessel, countercurrent acid hydrolysis takes place in the top of the vessel, and a countercurrent wash is effected in the bottom of the vessel. A part of the liquid in the return conduit of the first circulatory loop is diverted to one or more flash tanks, to produce steam and a liquid with a high concentration of hydrolysate. After hydrolysis and washing, the material is withdrawn from the bottom of the first vessel and passed through a second circulatory loop to the top of a kraft digester, preferably one having a steam phase at the top.
REFERENCES:
patent: 3380883 (1968-04-01), Richter et al.
patent: 3413189 (1968-11-01), Backlund
patent: 4174997 (1979-11-01), Richter
patent: 4236961 (1980-12-01), Green
patent: 4427453 (1984-01-01), Richter
patent: 4436586 (1984-03-01), Elmore
patent: 4456750 (1984-06-01), Martalla et al.
"Development of the Alva Prehydrolysis Process; Part Two: Mill Scale Application"; Blom et al, Tappi Proceedings, 1981 Pulping Conference.
"Billerud Pioneers Prehydrolysis-Kraft Pulping", Haas, reprint from Pulp & Paper International, Kamyr, Dec., 1967.
"Continuous Pulping Process", by Rydholm, reprinted by University Microfilms International, Special Technical Assn. Publication, Stap No. 7, pp. 105-119.
Alvo Steve
Kamyr Inc.
LandOfFree
Method of countercurrent acid hydrolysis of comminuted cellulosi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of countercurrent acid hydrolysis of comminuted cellulosi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of countercurrent acid hydrolysis of comminuted cellulosi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-701806