| 摘要 |
Process for extracting chemicals and energy from cellulose spent liquor, especially sulphate black liquor from a sulphate process for paper pulp comprising the following three distinct and separate stages: in the first stage the concentrated black liquor is gasified in a gasification reactor 1 at an excess pressure by means of so-called flame pyrolysis at 700-1300 degrees C, normally at 800-900 degrees C, high-energy gas being generated and organic chemicals of the black liquor entering in the form of molten, suspended drops, essentially containing sodium carbonate and sodium sulphide. In the second stage the gas from the gasification reactor 1 is cooled rapidly by direct contact with the water and green liquor produced when the molten drops and the hydrogen sulphide is released in the extinguishing liquid. The cooled gas then passes through a gas scrubber 15. In the lower section of the scrubber 15 the gas is scrubbed by means of circulating green liquor and in the upper section of the scrubber the gas is scrubbed by means of sodium hydroxide (or carbonate) solution and the water for complete removal of all residual sulphur compounds in the gas. In the third stage the now sulphur and particle-free gas is used as fuel for generating steam and, where profitable, for generating electricity. <IMAGE> |
