US-20260125606-A1 - PROCESS FOR REMOVING IMPURITIES IN FEEDSTOCKS

US20260125606A1US 20260125606 A1US20260125606 A1US 20260125606A1US-20260125606-A1

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 2 O 4 ), titania (TiO 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 2 .

Inventors

Christian Frederik WEISE
Michal Lutecki
Frank Bartnik JOHANSSON

Assignees

TOPSOE A/S

Dates

Publication Date: 20260507
Application Date: 20231017
Priority Date: 20221019

Claims (16)

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 2 O 4 ), titania (TiO 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 2 O 4 and TiO 2 , said mixture being 30-70 wt % MgAl 2 O 4 and 70-30 wt % TiO 2 .
3 . The process according to claim 1 , wherein the process further comprises: i-1) a prior step for preparing the MgAl 2 O 4 of said porous material by providing a starting material comprising MgAl 2 O 4 and subjecting it to calcination in air at 850-1050° C.; or i-2) providing a starting material directly as said MgAl 2 O 4 ; and/or ii-2) a prior step for preparing the TiO 2 of said porous material by providing a starting material comprising TiO 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 2 .
4 . The process according to claim 1 , wherein the titania (TiO 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 2 /g.
7 . The process according to claim 1 , wherein the MgAl 2 O 4 of the porous material is at least 90 wt % MgAl 2 O 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 Å.
8 . The process according to claim 1 , wherein the TiO 2 of the porous material is at least 90 wt % TiO 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 Å; and wherein the average pore size radius is 80-100 Å.
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 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

The invention relates to a process and plant for removing one or more impurities, for instance phosphorous (P), from a feedstock such as a renewable feedstock, by contacting the feedstock with a guard bed comprising a porous material, the porous material being: magnesium aluminate spinel (MgAl2O4), titania (TiO2), or a mixture thereof. Optionally, the porous material is silica (SiO2). Renewable fuels may be produced from a broad variety of sources including animal fats and vegetable oils but also tall oil, pyrolysis oils and other non-edible compounds. Before feedstocks derived from renewable organic material can be used in conventional automobile engines, aviation turbines, marine engines or other engines, and distributed using existing fuel infrastructure, it is desirable to convert the material into hydrocarbons similar to those present in petroleum-derived transportation fuels. One well-established method for this purpose is the conversion of vegetable oils into normal paraffins in the gasoline, jet fuel or diesel boiling range by employing a hydrotreating process. In a hydrotreating process, the renewable organic material is reacted with hydrogen at elevated temperature and pressure in a catalytic reactor. A particular problem with feedstocks such as renewable feedstocks is that they contain impurities such as phosphorus-containing or silicon-containing species. Phosphorus-containing species may take the form of phospholipids such as lecithin, from seed oils. Waste lube oils can also contain species such as zinc dialkyl dithio phosphates (ZDDP), which acts as an anti-wear additive in such lubricants. Phosphorus (P) quickly deactivates conventional catalysts for hydrotreating and reduces cycle length dramatically. The refiners processing renewable feedstocks are forced to load more material for guarding the hydrotreating catalyst compared to fossil fuel-based refining processes. The units often employ pre-treatment of the feedstocks using washing and/or adsorbents to reduce P from 10-20 ppm down to 1-2 ppm, but even at 1-2 ppm, guard materials are needed. Thus, refiners processing renewables, whether by using only renewables as the feedstock, or a mixture of renewables and fossil fuels i.e. co-processing, uniformly express the need for better guard materials for particularly P capture to prevent pressure drop and deactivation of their bulk catalysts. It is therefore vital to reduce, or—if possible—remove, impurities, particularly phosphorus-containing species before reaching the bulk catalyst. The concept of “guard beds” for catalytic processes are known. For instance, from U.S. Pat. No. 5,879,642. An upstream catalyst bed functions as a guard catalyst bed for removing a major proportion of impurities from a hydrocarbon feed stream in order to extend the life of one or more catalyst beds located underneath (downstream) the guard catalyst bed. U.S. Pat. No. 9,447,334 (US 2011/138680) discloses a process for converting feeds derived from renewable sources with pre-treatment of feeds, whereby upstream of the hydrotreatment step, a step for intense pre-treatment for eliminating hetero-elements such as phosphorus which are insoluble under hydrotreatment conditions, is conducted. This step includes the use of an adsorbent free of catalytic material (free of catalytic metals), having a high surface area e.g. 140 m2/g and high total pore volume e.g. 1.2 ml/g. US 2004/077737 discloses a catalyst for use for Fischer-Tropsch synthesis which comprises 3-35 wt % cobalt supported on alumina, the alumina support having a surface area of <50 m2/g and/or is at least 10% alpha-alumina. The cobalt (Co) is suitably combined with the metal promoters Re or Pt. In particular, where Co is promoted with Re or Pt, the content of Co in the catalyst is 5 wt % or higher. When using only Co in the catalyst, its content is 12 wt % or higher. U.S. Pat. No. 4,510,092 discloses a method of continuously hydrogenating fatty materials, in particular liquid vegetable oils, over a nickel on alpha-alumina catalyst whose surface area is <10 m2/g, the micropore volume is <0.1 ml/g and the macropore volume is <0.6 ml/g, preferably <0.3 ml/g. By micropore volume is meant the total volume of pores under about 117 Å in size; while by macropore volume is meant the total volume of pores greater than about 117 Å in size. The nickel content is high, namely 1-25%. U.S. Pat. No. 4,587,012 discloses a process for upgrading a hydrocarbonaceous stream for removing the metal impurities nickel, vanadium and iron, using a catalyst which comprises more than 80% alpha-alumina. The catalyst material has a pore volume (PV) of only about 500 ml/kg (0.5 ml/g) and no more than 10% macropores, i.e. there is no more than 10% of PV being in pores with radius >500 Å (diam. >1000 Å). Conventional and commercially available guard bed materials used for P capture are in the form of a catalyst made of high pore volume gamma-alumina carrier with low metal content for hydrotre