Soda black liquor

Harris et al. (15) carried out similar hydrogenations in aqueous and 1% alkaline media over Raney nickel for 6-10 hours at 225°-250°C. and 1500-2500 p.s.i.g. hydrogen pressure the products were identical with those found in dioxane. In 1941 lignin from soda black liquors was hydrogenated over copper chromite in dioxane at 250°-300°C., and colorless saturated products were obtained (/). Cyclohexane and four alkylcyclo-hexanes were detected, but the major part of the lignin was converted to alcohols and glycols related to polycyclic hydrocarbons of 20-70 (or more) carbon atoms. 

Dhingra DR, Bhatnagar MS, Nigam PC. Lignin recovery from soda black liquor. Indian Pulp Pap 1952 7 311-5. 

Barium Hydrate Barium Nitrate Benzoic Acid Benzyl Alcohol Black Liquor, Soda Black Liquor, Sulphate Boric Acid Butyric Acid... 

Ghatak, H. R. [2008). Spectroscopic comparison of lignin separated by electrolysis and acid precipitation of wheat straw soda black liquor. Ind. Crops Prod., 28,206-212. 

Various permutations of the black liquor recovery boiler design are used to combust soda liquors in the soda pulping process and alkaline earth liquors and ammonium liquor (red liquor) in the sulfite pulping process. 

Keywords Black liquor, crystallization process, oil palm empty fmit bunches, soda lignin, vanillin... 

The pH of the obtained black liquor was 12. 45 and its density 1.02 g/iuL. The soda lignin was then precipitated from the concentrated black hquor by acidifying it to pH 2 using 20% concentrated sulfuric acid (H SO ). The precipitated hgnin was then filtered and washed with water adjusted to pH 2 using H SO. Then, the soda lignin was dried in a vacuum oven at 55°C for 24 hours prior to further analysis [12]. 

Black liquor Recovery furnaces for krali and soda-pulping processes 5-7... 

Historically, a classic example of an evaporation process is the production of table salt. Maple syrup has traditionally been produced by evaporation of sap. Concentration of black liquor from pulp and paper processing constitutes a large-volume present application. Evaporators are also employed in such disparate uses as desalination of seawater, nuclear fuel reprocessing, radioactive waste treatment,preparation of boiler feed waters, and production of sodium hydroxide. They are used to concentrate stillage waste in fermentation processes, waste brines, inorganic salts in fertilizer production, and rinse liquids used in metal finishing, as well as in the production of sugar, vitamin C, caustic soda, dyes, and juice concentrates, and for solvent recovery in pharmaceutical processes. 

The black liquor used in this research work comes from the soda pulping of straw. The main components of these black liquor are three organic compounds, which come from the straw solution during the pulping, inorganic salts of sodium and potassium, and water. Moreover, it is important to indicate that the content of carbonates can reach 4.87 % wt. 

Black Liquor from Soda-pulp Mills.—One ton of pulp will produce about 3,300 gal. of 5 deg. liquor, and this is concentrated to 35 deg. in multiple-effect evaporators of the horizontal and film type, with a capacity of from 2 to 2K gal. per square foot, according to the steam pressure, which will be from 10 to 25 lb., with a vacuum of from 27 to 28 in. Special construction and separators are necessary on account of the excessive foaming. Evaporators must have cast-iron or steel shells with wrought-iron or steel tubes, as the liquors are strongly alkaline. 

BLACK LIQUOR - The liquid material remaining from puipwood cooking in the soda or sulfate papermaking process. 

In soda pulping there are similar condensation reactions as those described above for kraft pulping. In this case, however, the black liquor does not have strong nucleophiles (such as sulphide or hydrosulphide) that might block condensation of the quinone methide intermediates with the carbanions. Hence, lignin condensation may be more prevalent for soda than for kraft pulping. 

Black liquor from kraft or soda mills pulping hardwoods may present problems during its evaporation and combustion by conventional methods. These problems have been encountered with some eucalypt species, particularly with wood from trees of old age, and special measures may be needed to overcome the problems caused by extractives. Apart from the formation of deposits and scale, which reduces heat transfer in the evaporators, the extractives increase the viscosity (so that the evaporation process is affected) and reduce the swelling properties when incinerated, resulting in incomplete combustion (130). These difficulties with black liquor from the soda process can be avoided with the use of a wet oxidation process conducted under high pressure (97). 

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