Method for pyrolysis of carbohydrates

摘要

Technical pyrolysis of carbohydrate or carbohydrate mixture, comprises adding amorphous carbon. Independent claims are also included for: (1) a composition, preferably pyrolysis product, obtained by the above method; (2) a pyrolysis product of at least one carbohydrate exhibiting a very low ash content of less than 0.5 wt.%, preferably 0.000001-0.001 wt.%, and/or a content of (a) aluminum of less than 5 ppm, or 5 ppm-0.0001 ppt, preferably 1 ppb-0.0001 ppt, (b) boron of less than 10 ppm-0.0001 ppt, preferably 1 ppb-0.0001 ppt, (c) calcium of = 2 ppm, preferably 1 ppb-0.0001 ppt, (d) iron of = 20 ppm, preferably 1 ppb-0.0001 ppt, (e) nickel of = 10 ppm, preferably 1 ppb-0.0001 ppt, (f) phosphorus of less than 10 ppm-0.0001 ppt, preferably 1 ppb-0.0001 ppt, (g) titanium of = 2 ppm, preferably 1 ppb-0.0001 ppt, and (h) zinc of = 3 ppm, preferably 1 ppb-0.0001 ppt; (3) producing silicon, preferably metallurgical silicon or solar silicon, comprising either pyrolyzing a mixture of carbohydrate, preferably carbohydrate purified using ion exchange column, and amorphous carbon, preferably high purity amorphous carbon, at a temperature of 400-700[deg] C, and using the pyrolysis product subsequently for producing silicon, preferably high purity silicon solar silicon, or introducing a mixture of carbohydrate, preferably carbohydrate purified using ion exchange column, and amorphous carbon, preferably high purity amorphous carbon, into the reduction reactor, in non-pyrolyzed form, producing carbon reducing agent in the reduction reactor in situ by pyrolysis, and subsequently reacting the pyrolyzed product with silicon dioxide or silicon carbide to obtain silicon, preferably high purity solar silicon; and (4) producing silicon, preferably solar silicon, comprising using a graphite electrode, a carbon brush, heating element or a heat exchanger, as apparatus components.