Patent GB-702821-A (GB)
Title: Process for the treatment of black liquor soap obtained in the manufacture of cellulosic material by the sulphate or soda process
Inventor: NITSCHE KARL SIGMUND
IPC: C08H5/00
Filed: 1949-04-16
Abstract: In the acid hydrolysis of black liquor soap from the sulphate or soda cellulose process, the hydrolysis is carried out in the presence of an alkali or alkaline earth salt such as sodium sulphate or sodium chloride, with or without the simultaneous passage of a gas such as air, carbon dioxide or sulphur dioxide. Upon standing the mass separates into three layers, of which the upper layer consists of tall oil, the middle layer is a coarse-grained mud, and the bottom layer is a concentrated solution of sodium sulphate or other salt and impurities.  The mud may be extracted with alcohol or other solvents to obtain phytosterines.ALSO:Black liquor soap from the sulphate or soda cellulose process is treated, before, during, or after the known acid hydrolysis, with an alkali or alkaline earth salt such as sodium sulphate or chloride, with or without passage of air, carbon dioxide or sulphur dioxide.  On standing, the mass separates into three layers, of which the upper layer consists of purified tall oil, the middle layer is a coarse-grained mud and the bottom layer is a concentrated solution of sodium sulphate or other salt and impurities.  The mud may be used to prepare a moulding powder (see Group V) or phytosterines (see Group IV (b)).  According to examples, (1) black liquor soap is heated with about 10 per cent. of water, and 15 per cent. of sodium sulphate is slowly added; carbon dioxide may be blown through at the same time or previously; sulphuric acid is then added, air is blown through for some time, and the mass is allowed to stand; the top layer consists of brownish clear tall oil; (2) black liquor soap is heated with 5 per cent. of water, 12 per cent. of sodium chloride is added, and the whole is slowly acidified with hydrochloric acid, whereupon air is blown through and the mass is allowed to stand, giving a somewhat lighter tall oil.  The Specification as open to inspection under Sect. 91 includes an example in which black-liquor soap is heated with water and blown with air containing sulphur dioxide; sulphuric acid is then added, and the mixture is air-blown and then allowed to stand, to permit separation of tall oil.  This subject-matter does not appear in the Specification as accepted.ALSO:In the acid hydrolysis of black liquor soap from the sulphate or soda cellulose process, the hydrolysis is carried out in the presence of an alkali or alkaline earth salt such as sodium sulphate or sodium chloride, with or without the simultaneous passage of a gas such as air, carbon dioxide or sulphur dioxide. Upon standing, the mass separates into three layers, of which the upper layer consists of tall oil, the middle layer is a coarse-grained mud, and the bottom layer is a concentrated solution of sodium sulphate or other salt and impurities.  The mud is separated, neutralized, treated if desired with alum or other aluminium salt or with a zinc or iron salt to insolubilize some of the components, filtered, dried, mixed with fillers, ground and used as a moulding powder.  If desired, it may be extracted with alcohol, which removes phytosterines and other plasticizing components, thus producing a product which yields a hard, brittle moulded article. The extracted plasticizers may also be added to portions of the moulding powder, with some of the tall oil if desired, to produce relatively soft, elastic products.  In typical examples, (1) tall oil mud is heated with wood flour and water, neutralized and dyed with direct black and carbon black; alum solution is then added and the mass is dried and ground; (2) tall oil mud is heated with calcined pyrites (a waste product from the sulphate cellulose process), sawdust and water from the washing of calcined pyrites, dried and comminuted; (3) moulding powders produced by different variations of the process are mixed together to give variegated effects.