Abstract: Granulated papermaking sludge is combined with plastic to form composite materials that may be shaped into structural and non-structural articles.

Abstract: Granulated papermaking sludge is combined with plastic to form composite materials that may be shaped into structural and non-structural articles.

Abstract: Liquid and solid de-icing and anti-acing agents comprise neutral or alkaline, non-chloride, non-phosphate and non-glycol compositions that are biodegradable, non-toxic, and environmentally benign. Liquid compositions are based on aqueous solutions of one or more organic acid salts such as lactic acid, succinic acid, acetic acid, and formic acid salts (preferably potassium or sodium). Solid compositions comprise organic-based porous pulp and paper sludge granules impregnated with a liquid de-icing composition or its ingredient(s), and dried. The liquid compositions can be obtained either by direct mixing of commercially available chemicals, or by chemical transformation of commercially available acids, or by fermentation of glucose, sucrose, fructose, or other sugars, or combination thereof.

Abstract: Extraction of calcium salts from papermaking sludge or sludge-derived ash is accomplished by mixing with a solution of an inorganic or organic acid. The acid extraction typically results in solubilization of other salts as well, e.g., those of aluminum, magnesium and iron. However, because these non-calcium salts precipitate as hydroxides at lower pH than calcium hydroxide, a caustic (or any other alkaline agent, in a solid or liquid form) is gradually added to precipitate non-calcium salts to facilitate their removal from solution (generally by filtration or centrifugation) prior to precipitation of calcium hydroxide. The desired calcium salt is then precipitated through addition of the appropriate acid anion (either by way of the acid or a salt having greater water solubility than the resulting calcium salt).

Abstract: Extraction of minerals from papermaking sludge or sludge-derived ash is accomplished by mixing with a solution of an inorganic or organic acid--generally 0.1% to 35% by weight, preferably 2% to 20%, and most preferably 3% to 8% by weight. In preferred embodiments, the material is carried as an aqueous solution and combined with 2% to 20%, and most preferably 3% to 6%, HCl; 2% to 25%, and most preferably 8%, HNO.sub.3 ; 2% to 30%, and most preferably 8%, acetic acid. Generally, the amount of acid added into the reaction mixture preferably is 0.8 to 2.0 times the stoichiometric calcium carbonate content in the mixture, more preferably 0.8 to 1.2 times the stoichiometric content, and most preferably matched to the stoichiometric content of calcium carbonate in the mixture. The acid-containing mixture is incubated (with agitation, if desired, to shorten the reaction time) to solubilize the desired minerals, following which the liquid phase is isolated, and mineral salts recovered therefrom.

Abstract: Glucose is obtained from papermaking sludge by first removing calcium carbonate from the sludge to produce a mixture substantially depleted of calcium and containing cellulose; and then hydrolyzing the calcium-depleted mixture using either a dilute or a strong acid. The glucose, as well as calcium salts removed from the sludge, may be isolated and used in numerous applications.

Abstract: A thermochemical process is provided for the use of pulp and paper sludge as a source of lignin through extraction and recovery. Pulp and paper sludge contains common components of plant materials as well as minerals employed in papermaking. Sludge is mixed in an alkaline solution (NaOH 0.4% to 4% by weight, preferably 0.5% to 2%, and most preferably 1% NaOH by weight). The solution is heated in an autoclave at a temperature of 150.degree.-250.degree. C. (preferably 180.degree.-220.degree. C., and most preferably 200.degree. C.) for a short time, e.g., from about half an hour to an hour. The extracted lignin, present in the alkaline solution, is precipitated by lowering the pH of the solution to a value of 3-5 with the use of, for example, an inorganic or organic acid. The precipitated solid lignin is then recovered and dried.

Abstract: The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions.

Abstract: The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions.

Abstract: The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions.