*3.2. Precipitation of the Lignin from Formosolv Black Liquor*

In order to collect an adequate amount of lignin for the study of its physicochemical properties, a larger reactor was used at the optimum conditions. The black liquor was treated with different proportions of water to evaluate the precipitation rate as a function of the dilution factor. The curve soon reached an asymptotic value at a dilution factor of 3 mL water/mL liquor. The recovery, gravimetrically measured, was 104% of the lignin dissolved. This value exceeds 100% because the solids consisted of not only pure lignin, but also associated carbohydrates (11%) and FA (1.6%). − − − −

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