Making Activated-carbon From Black Liquor Lignin Of Pulping

Black liquor from pulp and paper making industry is one of the most serious pollutants around the world. The drainage badly pollutes the environment so that many countries consider it as a very important issue. Traditional alkaline recovery technique is available to those large-scale pulping corporations in which the raw material is wood. However, it meets many unconquerable problems on economy and technique when it is used in those corporations in which the yield is under 10,000 tons annual or the raw material is non-wood. The resolution of black liquor pollution is very important to these corporations, and also important to the sustained development of pulp and paper industry, as well as our national economy.In our country, wood material is short and wheat straw is the main raw material for pulping. The objective of this dissertation is to treat the black liquor from pulping process, which emphasizes on researching the resourceful and harmless disposing of straw alkali pulping black liquor. This dissertation includes: 1.Black liquor, the extraction of two kinds black liquor lignin, making activated carbon, the most important is to research the absorption of Methylene blue and yield of the activated carbon, find the optimum process condition from the experiment.2.The filtering water of precipitated lignin is disposed through flocculation, getting the product of certain industrial value, the treated water is eligible to be drained.The conifer lignin actived carbon's absorption competence of methylene blue can reach 19.6ml/0.1g after the three factors are optimized(activated temperature 550℃ .reagent ratio 4.5:1,activated time 40min),the yield of activated carbon is 40.75%.The straw lignin actived carbon's absorption competence of methylene blue can reach 15.5ml/0.1g after the three factors are optimized(activated temperature 600 °C,reagent ratio 3.5:l,activated time70min),the yield of activated carbon is 30.55%.The clear liquor' absorbency from flocculating is 0.433,its COD is 7000~8000 mg/L.The clear liquor'pH can reach 6.0 after flocculation,which creates good condition for further treatment.This dissertation provides a new method to dispose black liquor. We could obtain the byproduct of high profit and have the hope to accomplish industrialized disposing black liquor.