Method for removing arsenic using a removal mass made of nickel oxide particles
The invention describes a process for the capture of organometallic impurities in a hydrocarbon feedstock of gasoline type containing olefins and sulfur, in which a capture body is brought into contact with the feedstock to be treated and a stream of hydrogen, said capture body comprises an active phase based on nickel oxide particles with a size of less than or equal to 15 nm, said active phase not comprising other metal elements of Group VIb or Group VIII, which are deposited on a porous support chosen from the group consisting of aluminas, silica, silicas/aluminas, or also titanium or magnesium oxides, used alone or as a mixture with alumina or silica/alumina.
1. A process for the capture of organometallic impurities in a hydrocarbon feedstock of gasoline type containing olefins and sulfur, in which a capture body is brought into contact with the feedstock to be treated and a stream of hydrogen at a temperature of between 200 and 400° C., a pressure of between 0.2 and 5 MPa and a ratio of the flow rate of hydrogen to the flow rate of hydrocarbon feedstock of between 50 and 800 Nm 3 /m 3 , said capture body comprises an active phase consisting of nickel oxide particles with a size of less than or equal to 15 nm, said active phase not containing other metal elements of Group VIb or Group VIII, which are deposited on a porous support selected from the group consisting of aluminas, silica, silicas/aluminas, titanium oxides and magnesium oxides, used alone or as a mixture with alumina or silica/alumina, the nickel content of the capture body, expressed as nickel element, is between 12% and 36% by weight with respect to the total weight of the capture body, the capture body having been prepared by either
a first process comprising at least the following stages:
i) a stage of bringing said support into contact with at least one solution containing at least one nickel precursor,
i′) a stage of bringing said support into contact with at least one solution containing at least one organic compound comprising oxygen and/or nitrogen and/or sulfur, stages i) and i′) being carried out separately, in any order, or simultaneously, to obtain an impregnated support,
ii) a stage of drying said impregnated support at a temperature of less than 250° C. to obtain a dried capture body, and
iii) a heat treatment stage at a temperature of between 250° C. and 1000° C. of the dried capture body:
or
a second process comprising at least the following stages:
i) a stage of bringing said support into contact with at least one solution containing ammonium ions and containing at least one nickel precursor, to obtain an impregnated support;
ii) a stage of drying said impregnated support at a temperature of less than 250° C. to obtain a dried capture body, and
iii) a heat treatment stage at a temperature of between 250° C. and 1000° C. of the dried capture body.
2. The capture process as claimed in claim 1 , in which the feedstock to be treated is a catalytic cracking gasoline containing between 5% and 60% by weight of olefins, from 50 ppm to 6000 ppm by weight of sulfur, as well as traces of arsenic in contents of between 10 ppb and 1000 ppb by weight.
3. The capture process as claimed in claim 1 , in which the size of the nickel oxide particles of the active phase of the capture body is between 1 and 10 nm.
4. The capture process as claimed in claim 1 , in which the total pore volume of the capture body is greater than or equal to 0.45 ml/g.
5. The capture process as claimed in claim 1 , in which the BET specific surface of the capture body is at least 40 m 2 /g.
6. The capture process as claimed in claim 1 , in which the active phase of the capture body is sulfurized in situ.
7. The capture process as claimed in claim 1 , in which the organometallic impurities are chosen from heavy metals, silicon, phosphorus and arsenic.
8. The capture process as claimed in claim 1 , in which said capture body is placed in a reactor located upstream of a hydrodesulfurization unit containing a hydrodesulfurization catalyst and/or of a selective hydrogenation unit containing a catalyst for the selective hydrogenation of said feedstock.
9. The capture process as claimed in claim 8 , in which the ratio of volume of said capture body, with respect to the volume of said selective hydrogenation and/or hydrodesulfurization catalyst, is between 4% and 50%.
10. The capture process as claimed in claim 1 , in which said capture body is placed in the actual interior of a reactor for the selective hydrogenation and/or hydrodesulfurization of said feedstock, at the head of said reactor.
11. The capture process as claimed in claim 10 , in which the ratio of volume of said capture body, with respect to the volume of said selective hydrogenation and/or hydrodesulfurization catalyst, is between 4% and 50%.
12. The capture process as claimed in claim 10 , wherein the capture body has been prepared by said first process.
13. The capture process as claimed in claim 10 , wherein the capture body has been prepared by said second process.