US3448004A - Preparation of chemical pulp from wood chips - Google Patents

Preparation of chemical pulp from wood chips Download PDF

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Publication number
US3448004A
US3448004A US560876A US3448004DA US3448004A US 3448004 A US3448004 A US 3448004A US 560876 A US560876 A US 560876A US 3448004D A US3448004D A US 3448004DA US 3448004 A US3448004 A US 3448004A
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US
United States
Prior art keywords
cooking
sulfite
dimethylamide
chemical pulp
dimethylamides
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US560876A
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English (en)
Inventor
Stanley J Buckman
Charles P Kirchen
Claude G Gendron
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Buckman Laboratories Inc
Original Assignee
Buckman Labor Inc
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Filing date
Publication date
Application filed by Buckman Labor Inc filed Critical Buckman Labor Inc
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Publication of US3448004A publication Critical patent/US3448004A/en
Anticipated expiration legal-status Critical
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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
    • D21C3/00—Pulping cellulose-containing materials
    • D21C3/22—Other features of pulping processes
    • D21C3/222—Use of compounds accelerating the pulping processes

Definitions

  • This invention relates to the preparation of chemical pulp from cellulosic material by the surfate and sulfite processes. More particularly, the present invention constitutes an improvement over known processes of producing chemical pulp by digesting cellulosic materials such as wood chips by the sulfate and sulfite processes.
  • sulfite process includes bisulfite and sulfite processes utilizing ammonium, alkaliand akaline-earthmetal bisulfite or sulfite solutions under neutral or acidic conditions.
  • the objects of this invention are accomplished by employing an N,N-dimethylamide of a straight chain carboxylic acid as a cooking aid during the digestion of the cellulosic material in the sulfate and sulfite processes.
  • a suitable N,N-dimethylamide of a straight chain carboxylic acid is prepared from a carboxylic acid contain ing 18 carbon atoms.
  • Preferred acids are further characterized by having at least one carbon to carbon double bond, because such acids and the N,N-dimethylamides thereof are normally a liquid which is an aid in handling.
  • a saturated acid such as stearic may be used to prepare an eificient N,N- dimethylamide cooking aid.
  • we prefer not to use the saturated acids because both the acid and the dimethylamide are solids at normal temperatures, causing handling difiiculties.
  • the melting points f the N,N-dimethylamides of the saturated acids are relatively high and, as a consequence, these amides tend to form deposits in the papermaking system with a drop in temperature.
  • Specific preferred acids include: oleic, linoleic, linolenic, ricinoleic, and mixtures thereof.
  • the mixed acids found in tall, castor, corn, cottonseed, linseed, olive, peanut, rapeseed, safflower, sesame, and soybean oils which, of course, produce a mixture og N,N-dimethylamides.
  • a mixture of carboxylic acids particularly suitable for use in our invention is that available commercially as tall oil fatty acids under the trademark Unitol ACD.
  • a typical analysis of this product is as follows:
  • the dimethylamide may be conveniently and preferably added continuously into the high-pressure acid accumulator. Since most highpressure accumulators are equipped with a recirculating pump which continuously recirculates the sulfite solution, the N,N-dimethylamide may be added to the suction or to the discharge line of the pump. If the high-pressure accumulator is not provided with a recirculating pump,
  • the N,N-dimethylamide may be added to the low-pressure acid accumulator or to the raw acid storage tank.
  • the N,N-dimethylamide may be siphoned into the cooking acid line going to the sulfite digester. When this procedure is followed, care must be taken to assure even distribution of the N,N-dimethylamide throughout the cooking acid.
  • concentration of N,N-dimethylamides actually used in the cooking process is not necessarily equal to the amount of the N,N-dimethylamide added to the system over the amount of cellulose fiber cooked during a given time.
  • the concentration of the N,N-dimethylamide in the acid after equilibrium has been reached may be several times that obtained in a single cook evaluation.
  • the N,N-dimethylamide or a mixture of such amides may be added to the white liquor going to the digester.
  • suitable and preferred quantities vary from 50 to 2,000 parts and 400 to 1,200 parts per million parts of moisture-free cellulose fiber, respectively. It will be understood, of course, that larger quantities of the N,N-dimethylamide may be used with no detrimental effect, but such larger quantities increase the costs of operation with limited material benefit.
  • N,N-dimethylamides may be added to all types of sulfite systems, such as the conventional calcium (lime), milk of lime, sodium, magnesium and ammonia base acid sulfite pulping with highly beneficial results.
  • sulfite systems such as the conventional calcium (lime), milk of lime, sodium, magnesium and ammonia base acid sulfite pulping
  • Run No. 1 was a conventional bisulfite digestion of coniferous wood chips for the production of chemical pulp to :be used for long fibers in the manufacture of newsprint as a control, and Run No. 2 was a duplicate of No. 1 with the exception that a mixture of N,N-dimethylamide was used as a cooking aid.
  • the results of Run No. 1 are averages of data compiled during the six weeks prior to the trial Run No. 2.
  • the results of Run No. 2 are averages of results obtained during the six days of trial Run No. 2.
  • Run No. 2 the procedure of Run No. 1 was repeated with the exception that a mixture of N,N-dimethylamides of tall oil fatty acids was added to the digester at the beginning of the cooking in an amount equal to 800 parts per million parts of moisture-free cellulose fiber.
  • the analysis of the tall oil fatty acids used to prepare the mixture of N,N-dimethylamides used is given in Table 1.
  • a comparison of the control and the N,N-dimethylamides bisulfite cooks is summarized in Table 2.
  • the cooking acid used was a magnesium base sulfite liquor containing 5.2 percent total S0 with a pH of about 3.8.
  • Example 2 The results obtained in Example 2 as compared to those in Example 1 were as follows:
  • EXAMPLE 3 The procedures of Examples 1 and 2 were repeated in which the N,N-dimethylamides of the mixed acids found in castor, corn, cottonseed, linseed, olive, peanut, and soybean oils were used instead of the N,N-dimethylamides of tall oil fatty acids. The results were similar to those obtained in Examples 1 and 2.
  • Run No. 1 involved the digestion of hardwood chips for the production of chemical pulp to be used for fibers in the manufacture of corrugating medium by a conventional continuous process operating at a production rate of 220 tons of pulp per day.
  • Digestion conditions were as follows: pressure 150 p.s.i.g., temperature 366 F., and a reaction time of 16 minutes.
  • the cooking liquor which contained 1 pound of sodium sulfite and 0.45 pound of sodium carbonate per gallon was added to the digester at a rate of 37 gallons per minute.
  • Consistency in the primary refiners was about 28 percent and in the secondary refiners it ranged from 4.6 to 5.1. Freeness averaged about 465 (Canadian Standard) out of the secondary refiners.
  • Run No. 2 the procedure of Run No. 1 was repeated with the exception that a mixture of tall oil fatty acids (same as used in Run No. 2 of Example 1) was introduced into the cooking liquor on the intake side of the pump delivering the liquor to the digester at a rate of about 300 parts per million parts of moisture-free cellulosic fiber.
  • EXAMPLE 5 The effectiveness of the mixture of N,N-dimethylamides prepared from Unitol ACD tall oil fatty acids as a cooking aid in reducing cooking time, thus increasing production in continuous digestion process (kraft process), was determined by comparing the results obtained by carrying out the cooking process in the absence of the dimethylamides (Run No. 1) to a similar cooking process in the presence of the dimethylamides (Run No. 2).
  • Contact time in the third zone was 45 minutes.
  • the liquor consistency or ratio of the cooking liquor to wood at the discharge of the digester was 18.5 percent.
  • Run No. 2 the procedure of Run No. 1 was repeated wtih the exception that a mixture of tall oil fatty acids (same as used in Run No. 2 of Example 1) was introduced into the cooking liquor on the intake side of the pump delivering the liquor to the digester at a rate of about 800 parts per million parts of moisture-free cellulosic fiber.
  • N,N-dimethylamides as disclosed herein are added to other processes such as the soda process of producing chemical pulp and the production of groundwood from bolts or chips after chemical impregnation followed by defibering with conventional stone grinders or disc refiners or various modifications thereof.
  • pulping chemical is ammonium, alkalior alkaline-earth-metal bisulfite or sulfite.
  • straight chain carboxylic acid is a mixture of straight chain carboxylic acids containing 18 carbon atoms and at least one carbon to carbon double bond.

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US560876A 1966-06-27 1966-06-27 Preparation of chemical pulp from wood chips Expired - Lifetime US3448004A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US56087666A 1966-06-27 1966-06-27

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US3448004A true US3448004A (en) 1969-06-03

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US560876A Expired - Lifetime US3448004A (en) 1966-06-27 1966-06-27 Preparation of chemical pulp from wood chips

Country Status (12)

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US (1) US3448004A (nl)
AT (1) AT273654B (nl)
BE (1) BE692672A (nl)
BR (1) BR6786412D0 (nl)
CH (1) CH487298A (nl)
DE (1) DE1692839B1 (nl)
DK (1) DK122467B (nl)
ES (1) ES335542A1 (nl)
FR (1) FR1507635A (nl)
NL (1) NL153284B (nl)
NO (1) NO119342B (nl)
SE (1) SE326094B (nl)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2651571A (en) * 1948-06-26 1953-09-08 Howard E St John Alkaline treating method for obtaining ramie and other fibers
US2725289A (en) * 1950-12-27 1955-11-29 Procedes Lourd Soc D Expl Des Process for the chemical retting of lengths of vegetable textiles
US2743179A (en) * 1953-07-22 1956-04-24 Socony Mobil Oil Co Inc Pitch control in paper making

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL302971A (nl) * 1963-04-29

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2651571A (en) * 1948-06-26 1953-09-08 Howard E St John Alkaline treating method for obtaining ramie and other fibers
US2725289A (en) * 1950-12-27 1955-11-29 Procedes Lourd Soc D Expl Des Process for the chemical retting of lengths of vegetable textiles
US2743179A (en) * 1953-07-22 1956-04-24 Socony Mobil Oil Co Inc Pitch control in paper making

Also Published As

Publication number Publication date
CH487298A (de) 1970-03-15
DE1692839B1 (de) 1971-07-01
AT273654B (de) 1969-08-25
BR6786412D0 (pt) 1973-08-09
NL153284B (nl) 1977-05-16
NO119342B (nl) 1970-05-04
DK122467B (da) 1972-03-06
BE692672A (nl) 1967-07-03
FR1507635A (fr) 1967-12-29
ES335542A1 (es) 1967-12-01
NL6701012A (nl) 1967-12-28
SE326094B (nl) 1970-07-13

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