Sulfite pulp from

Although the hydrolysis of wood to produce simple sugars has not proved to be economically feasible, by-product sugars from sulfite pulping are used to produce ethanol and to feed yeast (107). Furthermore, a hemiceUulose molasses, obtained as a by-product in hardboard manufacture, can be used in catde feeds instead of blackstrap molasses (108). Furfural can be produced from a variety of wood processing byproducts, such as spent sulfite Hquor, bquors from the prehydrolysis of wood for kraft pulping, hardboard plants, and hardwood wastes (109). 

MARATHON-HOWARD PROCESS. A treatment of waste sulfite liquor from sulfite pulp manufacture In recover chemicals and reduce steam pollution. The waste sulfite is treated with line and precipitates. (I) calcium sulfite for use in preparing fresh cooking acid for the sulfite pulp process, and 121 a basic calcium salt tif ligmn sulfonic acid (lignin sullYmalesi that can be pressed and used as a fuel of used as raw- material for vanillin, lignin plasties, and other chemicals. The remaining liquor with its BOD reduced X() ( is the effluent. 

Copper Value (Copper Index or Copper Number) of Cellulose It represents the amt of Cu reduced from the cupric to cuprous state in alkaline sola by lOOg of cellulose (such as cotton). In case of cotton, it gives an indication as to whether any appreciable changes have taken place during purification proceduresjin case of woodpulp, it indicates the degree of purity. Accdg to Doree (Ref 4 pp 26 32-3)>normal cotton cellulose has copper values below 0.2 while sulfite pulp has value>2. The alpha-cellulose obtd from sulfite pulp had a value of 0,8... 

Table XVII is an example of the test result showing comparable efficiency of SAE, PAE and alkylphenol ethoxylates in resin removal from sulfite pulp. A Japanese patent specification(24) by Lion Fats and Oils describes 10-16 mole ethoxylates of secondary alcohols as extremely useful in deresination of pulp, especially in the manufacture of dissolved pulp for the rayon industry. According to the patent specification, to alkyls give the best results among 12 mole ethoxylates ethoxylates of from 10 to 13 moles of EO can give the best results among other ethoxylates of C secondary alcohols, and the optimum amount of SAE(12E0) is in the range between 0.2 and 0.6% by weight based on pulp.

The major part of the dissolved material in bleaching originates from prebleaching (O and CE stages). In the case of kraft pulp, the most extensive dissolution takes place during the extraction stage, whereas even the initial chlorine treatment removes considerable amounts of lignin from sulfite pulp... 

Experiments with wood fiber pulps by the National Bureau of Standards have shown that the purer the pulp (higher the a-cellulose content) the more permanent it is. Moreover, as the a-cellulose content in these pulps approaches that of the a-cellulose content of rag fibers, the permanence of these fibers likewise approaches that of rag fiber. Therefore, paper made from sulfite pulps which have a high a-cellulose content would have better permanency properties than sulfate pulps provided that they are carefully made. 

Examples of the diminution of the pentosan of wood pulps by alkaline purification may be taken from the work of Richter. In a series of papers dealing chiefly with the pulping of hardwoods, Richter showed that either hot, dilute, sodium hydroxide or more concentrated sodium hydroxide at ordinary temperatures removes a substantial part of the pentosan from sulfite pulps. Some of Richter s data are shown in Table XVI. 

Lignin sulfonate byproducts from sulfite pulping make excellent binders for densified products (JJ, 1 2). Like other adhesives they require complete blending and adequate heating to make durable products. In excess they increase pelleting horsepower. Although available in quantity in the Northwest ligninsulfonates are presently burned for lack of markets. 

Viscose is a solution of cellulose xanthate in caustic soda. This solution can be processed into rayon or cellophane. The production of viscose consists of two steps. First, certain forms of cellulose, mainly from sulfite pulp and cotton linters, are reacted with pure caustic soda. This reaction converts the -OH groups on the cellulose unit to -ONa. The caustic soda must be pure and is obtained from mercury cells. Caustic soda from diaphragm cells contains sodium chloride which makes it unusable without purification. This solution must be aged for 2-3 days. Aging reduces the length of the cellulose chain which makes it easier to dissolve into caustic soda. The second step involves the reaction of the alkali cellulose and carbon disulfide in excess caustic soda. The net reaction of viscose is ... 

Assarsson A 1969 Release of resins from sulfite pulps. Svensk Papperstidn 72 380-385... 

The production of natural dyes for cottage industries producing custom cloth will continue. The production of cinnamon and liquorice root should survive as long as mankind has a sweet tooth. Despite the availability of synthetic vanillin from sulfite pulping liquors (16), vanilla beans are still produced for those who demand the genuine article. It is these facts that lead to the optimistic conclusion that the natural dyes, pharmaceuticals, oleoresins, and gums will continue to fill an important niche. 

The -SO3H (or Na) may be attached to the ring or the side chain of the phenylpropane structure of -> lignin but is still part of a polymeric network. Commercial 1., gained from sulfite pulping (- paper), may be either spent liquor or purified 1. or their derivatives. They are soluble in water over the total pH range but not in organic solvents. 

Structure and properties differ somewhat from 1. gained from sulfite pulping, but the application areas are mostly the same. 

Widely distributed in nature - starch, molasses, potatoes etc. Also obtained from sulfite pulp liquor. Used in foodstuffs (preservative, flavours, acidulant), plasticizers, mordants. In brewing, manuf. of cheese and confectionery. Depilatory for hides. Cryst., or colourless or yellowish syrupy liq. Sol. H2O, EtOH spar. sol. 

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