Adsorbent composition for removal of refractory sulphur compounds from refinery streams and process thereof
The present invention relates to a adsorbent composition for removing refractory sulphur compounds from refinery streams comprising of base component in the range of 10 to 50 wt %, spinel oxide in the range of 20 to 60 wt % as a reactive metal oxide component and bimetallic alloy in the range of 10 to 40 wt % acting as an adsorption enhancer component, wherein the adsorption enhancer component acts in synergy with base component. The invention also relates to a process for the preparation of said composition by mixing in solid state fine particles of base component, spinel oxide and bimetallic alloy, homogenizing the mixture thus obtained with solvent, peptizing the wet solid with dilute mineral acid, extruding the peptized material with extrusion aiding agents, drying the extrudates, further calcining the dried extrudates and reducing the calcined material under hydrogen flow.
1. An adsorbent composition for removal of refractory sulphur compounds from a refinery stream comprising:
Ingredient
w/w (%)
a)
a base clay component
about 10.0 to about 50.0;
b)
zinc nickel aluminate
about 45.0 to about 50.0;
c)
zinc nickel oxide
about 25.0 to about 40.0.
d)
alumina
about 0 to about 10.0, wherein the
absorbent compostion is devoid
of free zinc oxide.
2. The composition of claim 1 , wherein the base clay component further comprises alumina, magnesia, titania or combinations thereof.
3. The composition of claim 1 , wherein the base clay component comprises titanium oxide, ferric oxide, manganese dioxide, and silicon dioxide.
4. The composition of claim 1 wherein the composition has a surface area ranging from about 50 to about 200 m2/gm.
5. The composition of claim 1 wherein the composition has a pore volume ranging from about 0.1 to about 0.6 cc/gm.
6. The composition of claim 1 wherein the composition has an average pore size ranging from about 50 to about 200 Å.
7. The composition of claim 1 wherein the refinery stream includes at least one of heavy end gas oil, gasoline, naptha, kerosene, jet fuel and diesel fraction.
8. A process for preparation of an adsorbent composition for removal of refractory sulphur compounds from a refinery stream, the said process comprising:
a) mixing a base clay component in the range of about 10.0% to about 50.0% (w/w), a metal oxide component in the range of about 20.0% to about 60.0% (w/w), and an adsorption enhancer component in the range of about 10.0% to about 40.0% (w/w), wherein the adsorption enhancer component is a bimetallic alloy of metals selected from the group consisting of nickel, platinum, palladium, titanium and zinc;
b) grinding the above to fine particles;
c) homogenizing by milling with a solvent to form a wet solid;
d) peptizing the wet solid with dilute mineral acid;
e) extruding the peptized material;
f) drying the extrudates at a temperature of about 100-about 200° C. for about 4 to about 12 hours;
g) calcining the dried material at a temperature ranging from about 200-about 550° C. for a period of about 4 to about 12 hours;
h) reducing the calcined material under hydrogen flow at a temperature ranging between about 250-about 500° C.; and
i) obtaining dried adsorbent composition devoid of free zinc oxide.
9. The process of claim 8 wherein the solvent is selected from the group consisting of water, acetone and propanol.
10. The process of claim 8 , wherein the dilute mineral acid is dilute nitric acid.
11. The process of claim 8 further comprising applying an extrusion-aiding agent selected from a group consisting of polyvinyl alcohols, polyethylene glycols and carboxymethyl cellulose.