PROCESS FOR REMOVING IMPURITIES IN FEEDSTOCKS

Abstract

The invention relates to a process and plant for removing one or more impurities from a feedstock, said process comprising the step of contacting said feedstock with a guard bed comprising a porous material, thereby providing a purified feedstock; wherein the porous material comprises at least 80 wt % of magnesium aluminate spinel (MgAl.sub.2O.sub.4), titania (TiO.sub.2), or a mixture thereof; and the porous material has a total pore volume of 0.50-0.90 ml/g, as measured by mercury intrusion porosimetry. The invention envisages also a process and plant in which the guard bed comprises a porous material which is at least 80 wt % SiO.sub.2.

Claims

1. A process for removing one or more impurities from a feedstock, said process comprising the step of contacting said feedstock with a guard bed comprising a porous material, thereby providing a purified feedstock; wherein the porous material comprises at least 80 wt % of: magnesium aluminate spinel (MgAl.sub.2O.sub.4), titania (TiO.sub.2), or a mixture thereof; and the porous material has a total pore volume of 0.50-0.90 ml/g, as measured by mercury intrusion porosimetry.

2. The process according to claim 1, wherein the porous material comprises said mixture of MgAl.sub.2O.sub.4 and TiO.sub.2, said mixture being 30-70 wt % MgAl.sub.2O.sub.4 and 70-30 wt % TiO.sub.2.

3. The process according to claim 1, wherein the process further comprises: i-1) a prior step for preparing the MgAl.sub.2O.sub.4 of said porous material by providing a starting material comprising MgAl.sub.2O.sub.4 and subjecting it to calcination in air at 850-1050 C.; or i-2) providing a starting material directly as said MgAl.sub.2O.sub.4; and/or ii-2) a prior step for preparing the TiO.sub.2 of said porous material by providing a starting material comprising TiO.sub.2 and subjecting the starting material to calcination in air to below 500 C.; or ii-2) providing a starting material directly as said TiO.sub.2.

4. The process according to claim 1, wherein the titania (TiO.sub.2) is at least 99.9 wt % anatase.

5. The process according to claim 1, wherein the porous material comprises one or more metals selected from Co, Mo, Ni, W, and combinations thereof; and the content of the one or more metals is 0.25-20 wt %.

6. The process according to claim 1, wherein the porous material has a BET-surface area of 1-150 m.sup.2/g.

7. The process according to claim 1, wherein the MgAl.sub.2O.sub.4 of the porous material is at least 90 wt % MgAl.sub.2O.sub.4, and has a pore size distribution (PSD) in which at least 60 vol. % of the total pore volume is in pores with a radius below 400 .

8. The process according to claim 1, wherein the TiO.sub.2 of the porous material is at least 90 wt % TiO.sub.2, and has a pore size distribution (PSD) in which at least 90 vol. % of the total pore volume is in pores with a radius below 120 ; and wherein the average pore size radius is 80-100 .

9. The process according to claim 1, wherein the one or more metals comprise Mo and its content is 0.5-15 wt %.

10. The process according to claim 9, wherein the porous material is free of Co and/or W and further comprises 0.05-0.5 wt % Ni.

11. The process according to claim 1, wherein the one or more impurities are selected from a vanadium-containing impurity, silicon-containing impurity, a halide-containing impurity, an iron-containing impurity, a phosphorous-containing impurity, and combinations thereof; and further the process is carried out at high temperature such as 100-400 C., optionally in the presence of a reducing agent.

12. The process according to claim 1, wherein the feedstock is: i) a renewable source obtained from a raw material of renewable origin, or a feedstock derived from one or more oxygenates taken from the group consisting of triglycerides, fatty acids, resin acids, ketones, aldehydes or alcohols where said oxygenates originate from one or more of a biological source, a gasification process, a pyrolysis process, Fischer-Tropsch synthesis, or methanol based synthesis; or ii) a feedstock originating from a fossil fuel; or iii) a feedstock originating from combining a renewable source according to i) and a feedstock originating from a fossil fuel according to ii).

13. The process according to claim 12, wherein the portion of the feedstock originating from a renewable source is 5-60 wt %.

14. The process according to claim 1, wherein the one or more impurities is a phosphorous (P)-containing impurity and said feedstock contains 0.5-1000 ppm P.

15. The process according to claim 1, wherein the purified feedstock is subsequently processed in a hydrotreatment stage in the presence of a hydrotreatment catalyst.

16. The process according to claim 1, wherein the titania (TiO.sub.2) is at least 99.9 wt % anatase, and wherein the one or more impurities is a phosphorous (P)-containing impurity and said feedstock contains 0.5-1000 ppm P.

Description

EXAMPLES

[0103] Table 1 below shows results of porous materials according to the present invention compared with the prior art. Loss of ignition (LOI, wt %) as is well-known in the art, is used to measure the coking of the samples after use and thus as a proxy of carbon content (C, wt %). The total pore volume (PV) of the fresh sample is shown, as so is the P-capture (P-pick up) after use. No metals such as Mo were added. The tests were conducted in batch reactor tests by reacting a small amount of sample in a batch reactor with renewable feed at approximately 300 C. in the presence of hydrogen, as follows:

Sample Preparation:

[0104] Catalyst or carrier samples were crushed and sieved to a size of 300-600 microns.

Model Feedstock:

[0105] For 400 g feedstock, 6.65 g lecithin were dissolved in 197 g heptane after which 197 g of soy bean oil were added. This gives a phosphorous content of 800 ppm-wt.

Test Procedure:

[0106] 1.5 g of the sample together with 15 g of feedstock were added to a batch reactor. The reactor was sealed and flushed with nitrogen. After applying 50 bar of hydrogen pressure the reactor was heated to 320 C. (2.5 C./min) and held for 6 min at maximum temperature. After recovery of the sample particles, they were extracted with xylene using a Soxhlet apparatus to remove any heavy oil residues and dried in vacuum at 90 C.

Analysis:

[0107] The dried samples were analyzed for carbon using the LECO instrument and for P and Al by XRF analysis, as disclosed in applicant's WO 2022008508.

[0108] The mercury intrusion porosimetry for determining the total pore volume (PV) is conducted according to ASTM D4284.

TABLE-US-00001 TABLE 1 LOI, C, PV P-capture BET area, Sample wt % wt % (ml/kg) (g/L) m.sup.2/g A 12.3 8.43 804 4.53 115 B 8.9 517 7.30 131 C 6.4 4.22 550 5.30 66 D (prior art) 4.3 3.07 651 5.78 (77.7*) E 8 5.65 1416 3.00 304 A: 100 wt % MgAl.sub.2O.sub.4 after calcination of MgAl.sub.2O.sub.4 catalyst carrier material at 900 C.; B: 100 wt % TiO.sub.2 (anatase) after calcination below 500 C. of TiO.sub.2 catalyst carrier material or no calcination (no heat treatment) - the starting material is provided directly as the TiO.sub.2; C: 100 wt % MgAl.sub.2O.sub.4 after calcination of MgAl.sub.2O.sub.4 catalyst carrier material at 1000 C.; D (prior art): according to applicant's WO 2022008508, i.e. alpha-alumina based sample (sample 3, FIG. 1-2 therein). E: 100% SiO.sub.2 - the starting material is provided directly as SiO.sub.2. *Note: 77.7 g/L is the P-capture of applicant's WO 2022008508, which is not conducted in batch tests as in the present application, and thus not directly comparable.

[0109] The batch reactor tests show that A (100% MgAl.sub.2O.sub.4), B (100 wt % TiO.sub.2) and C (100 wt % MgAl.sub.2O.sub.4), in particular samples B and C, are good candidates for a guard bed, as these are similar or appear even better (sample B) in P-capture compared to sample D. Sample D, showing a P-capture of 5.78 g/L in the present batch tests, and used herein as reference porous material, corresponds to sample 3 FIG. 1-2 of WO 2022008508, being rich in alpha-alumina and comprising also theta-alumina. Sample D showed a high P-capture at industrially relevant conditions of about 600% higher than the reference therein (WO 2022008508, sample 1ref: >95 wt % gamma-alumina). Sample E (100% SiO.sub.2) shows a somewhat lower P-capture than samples A-C, and a carbon content on par with sample B.