| 主权项 |
1. A process for the production of middle distillate bases, comprising:
a) pre-treating of a semi-refined vegetable or animal oil, comprising passing said oil through a reactor comprising at least one fixed bed of at least one adsorbent comprising 100% porous refractory oxide that is optionally activated alumina, or silica-alumina, which porous refractory oxide is free of catalytic metals from group 6 and groups 8 to 12, at a temperature in the range of 130° C. to 320° C., at a pressure in the range of 0.1 to 7 MPa and with a residence time for said oil on said fixed bed in the range of 0.1 to 1 hour; said adsorbent having a macroporous volume, measured by mercury intrusion, of pores with a mean diameter of 500 Å of more than 0.1 ml/g, a total pore volume of more than 0.60 ml/g, and a specific surface area, expressed as the SBET, of 30 m2/g to 320 m2/g, b) hydrotreating, in the presence of at least one fixed bed catalyst, of the pre-treated effluent from a) at a temperature in the range 200° C. to 450° C., at a pressure in the range 1 MPa to 10 MPa, at an hourly space velocity in the range 0.1 h−1 to 10 h−1 and in the presence of a total quantity of hydrogen mixed with the feed such that the hydrogen/feed ratio is in the range 70 to 1000 Nm3 of hydrogen/m3 of feed; c) separating from the hydrotreated effluent derived from b), of the hydrogen, the gases and at least one middle distillate base, in which said semi-refined vegetable or animal oil is obtained by pre-refining an unrefined vegetable or animal oil before the pre-treatment process, the pre-refining comprising:
degumming, comprising eliminating at least a portion of the phospholipids or gums by precipitation in the presence of acidulated water;neutralizing, in the presence of a sodium hydroxide solution, of the degummed oil in order to neutralize at least a portion of the free fatty acids present in the oil;washing with water to eliminate traces of sodium salts; andvacuum drying. |
