Method for preparing a linear alpha olefin including oxygen removal from the feed
Provided is a method for preparing a linear alpha olefin using a chromium-based catalyst, including the steps of: removing oxygen impurities by contacting an olefin with an oxygen adsorbent; injecting the olefin from which the oxygen impurities are removed; a chromium-based catalyst into a reactor; and oligomerizing the olefin in the reactor.
1. A method for preparing a linear alpha olefin, the method comprising steps of:
removing oxygen impurities by contacting an olefin with an oxygen adsorbent;
injecting the olefin from which the oxygen impurities are removed, and a chromium-based catalyst into a reactor;
oligomerizing the olefin in the reactor; and
terminating the oligomerizing reaction by using a catalyst deactivator,
wherein the step of removing the oxygen impurities is performed under a temperature of 50 to 100° C.
2. The method of claim 1 , wherein the oxygen adsorbent is CuO, NiO, MoO 3 , zeolite 3A, activated alumina, or a mixture thereof.
3. The method of claim 1 , wherein the oxygen adsorbent has a specific surface area of 100 to 900 m 2 /g.
4. The method of claim 1 , wherein the step of removing the oxygen impurities is performed by passing the olefin through an adsorption tower filled with the oxygen adsorbent.
5. The method of claim 4 , wherein the olefin is injected into the adsorption tower at a gas hourly space velocity of 0.02 to 5 hr −1 .
6. The method of claim 4 , further comprising, after the step of removing the oxygen impurities, a step of regenerating the oxygen adsorbent.
7. The method of claim 6 , wherein the oxygen adsorbent is CuO, and the step of regenerating the oxygen adsorbent is performed by passing a mixed gas of hydrogen and nitrogen through the adsorption tower at 100 to 200° C.
8. The method of claim 7 , wherein a volume ratio of hydrogen and nitrogen in the mixed gas is 5:95 to 95:5.
9. The method of claim 1 , wherein the step of removing the oxygen impurities is performed under a pressure of 5 to 100 kg/cm 2 .
10. The method of claim 1 , wherein after the step of removing the oxygen impurities, an oxygen content in the olefin is less than 100 ppm.
11. The method of claim 10 , wherein the oxygen content in the olefin is 0 ppm.
12. The method of claim 1 , wherein the chromium-based catalyst is represented by CrL 1 (l 2 ) p (X) q or Cr 2 X 1 2 L 1 2 (L 2 ) y (X) z (where L 1 is a heteroligand, L 2 is an organic ligand, X and X 1 are each independently halogen, p is 0 or an integer of 1 or more, q is an integer of (oxidation number of Cr−p), y is an integer of 2 or more, and z is an integer of (2×oxidation number of Cr)−y).
13. The method of claim 1 , wherein the olefin is ethylene.
14. The method of claim 1 , wherein the catalyst deactivator is an oxygen-containing inorganic material selected from the group consisting of O 2 , CO 2 , CO, NO, NO 2 , N 2 O, N 2 O 3 , N 2 O 4 , N 2 O 5 and a mixture thereof; an organic compound including one or more of functional groups including at least one selected from the group consisting of oxygen, phosphorus, nitrogen and sulfur, and having a number average molecular weight of 400 or more; or 2-ethylhexanol.
15. The method of claim 14 , wherein the catalyst deactivator is an oxygen-containing inorganic material selected from the group consisting of O 2 , CO 2 , CO, NO, NO 2 , N 2 O, N 2 O 3 , N 2 O 4 , N 2 O 5 and a mixture thereof; or an organic compound including one or more of functional groups including at least one selected from the group consisting of oxygen, phosphorus, nitrogen and sulfur, and having a number average molecular weight of 400 or more.