| 摘要 |
A process for continuously producing bio-oil comprising the steps of a) forming a black liquor composition in a mixing tank (T) by mixing kraft black liquor,acidifying agent (AA1), in an amount sufficient to adjust the hydroxide ion concentration of the black liquor to 1-40 g/l, preferably 5-15 g/l based on the volume of black liquor;b) introducing the black liquor composition into a reactor (R), applying a pressure of 5-150 bar of H2 or H2/CO, and a hydrogen/ black liquor composition flow ratio of 50-3000 l/l, preferably 100-600 l/l, and reacting the black liquor composition at 220-350 °C for 10-120 minutes, preferably 30-60 minutes in the absence of a solid catalyst; or at 180-240 °C for 10-120 minutes, preferably 30- 60 minutes, in the presence of a solid catalyst,thereby causing depolymerization of lignin in the black liquor composition;c) cooling the composition to a temperature below the boiling point of a solvent to be added in a subsequent step;d) acidifying the composition by adding one or more acidifying agents (AA2) until a pH of 4-5 is reached;e) adding a solvent (S) to the composition, in order to extract oil from the composition; f) separating the composition by phase separation in a first separation step (S1) into an oil phase (A) comprising solvent, oil, and organic acids; a first water phase (B) comprising water, salts and non-depolymerized lignin solids; a second water phase (C1) comprising water and salts;g) filtering (F2) the first phase (A) to remove any particles;h) desalting the filtered first phase (A) by i) washing it by adding water and separating by phase separation in a second separation step (S2) into an oil phase (D) comprising oil and solvent, and a third water phase (C2) comprising salts; or ii) adding adsorbent and/or absorbent material or ion exchange material, or combinations thereof;h) evaporating (E2) the solvent comprised in the oil phase (D), thus obtaining a bio-oil;and j) recycling solvent evaporated in step i) to step e). |
