Method for utilizing lignin separated from black liquor as lime-kiln fuel
(22) 26.05.2015
(43) 10.12.2015
(57) The subject of the invention is a new method of utilizing lignin-containing material separated from spent kraft pulping Iiquor (black Iiquor) by (a) acidifying the Iiquor, or fraction thereof, to a pH not less than 7 thereby precipitating solid particles, (b) separating precipitated solid particles from the accompanying liquid and (c) subjecting material thus separated to a washing process exhibiting the following essential features: (i) separated material is washed with an aqueous medium or aqueous media in one or more steps, (ii) in each washing step, the washing medium contains, in a dissolved form, significant amounts of one or more added sodium salts, and (iii) the combined concentration of the added sodium salts in the washing medium in each washing step exceeds 3 % by weight, preferably exceeds 5 % by weight and most preferably exceeds 10 % by weight. Despite the relatively large amount of sodium left in the washed lignin-containing material, the material is, after possible partial or complete drying, utilized as fuel in a lime kiln of a pulp mill.
(71) Andritz Oy [FI/FI]; Tammasaarenkatu 1, FI-00180 Helsinki (FI)
(84) ARIPO (BW, GH, GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, KM, ML, MR, NE, SN, TD, TG)
