REACTIVE ADSORBENT COMPOSITION FOR REMOVAL OF REFRACTORY SULPHUR COMPOUNDS FROM REFINERY STREAMS AND PROCESS THEREOF
FIELD OF INVENTION:
The present invention relates to a reactive adsorbent composition(s) comprising of base component, spinel oxide as reactive metal oxide and bimetallic alloy as an adsorbent capacity enhancer component in synergy with base component for removal of refractory sulfur compounds from refinery streams. The invention also relates to a process for the preparation of said reactive adsorbent composition(s).
BACKGROUND OF THE INVENTION:
US Patent Publication No.2004/0007506 have made efforts to design the several adsorbents to physically adsorb the sulfur compounds selectively from the various hydrocarbon fuels e.g. gasoline, kerosene, jet fuel and diesel fuel etc.. These adsorbents showed the selectivity for other compounds e.g. aromatics and olefins etc. also and saturated at very low treated volume of the fuels. In the regeneration process, the adsorbed compounds were removed by solvent washing. The sulfur compounds were then recovered in concentrated forms by evaporation of the solvent. This concentrated sulfur containing stream is then treated in a small hydrotreater reactor and blended to the adsorbent treated product. The treating of this concentrated sulfur-containing stream will require severe operating conditions and higher consumption of hydrogen. This process may not be economically viable due to low selectivity, faster saturation, treating of concentrated sulfur containing streams and low recovery of the fuel streams.
U.S Patent Publication No. US2003/03255 Ai discloses an adsorbent prepared by the conventional impregnation of a sorbent support comprising zinc oxide, expanded perlite, and alumina with a promoter metal such as nickel, cobalt.
U.S Patent Publication No. US2004/0063576Ai discloses a catalyst adsorbent comprised of nickel compound deposited on a silica carrier by using conventional precipitation process. Alumina and alkaline earth compounds are used as promoters
U.S Patent, 6,803,343 discloses a sorbent composition comprising, a support system prepared by admixing zinc oxide with silica/ alumina, and incorporating the support with reduced valence noble metal.
U.S Patent, 6,683,024 discloses a sorbent composition, which contains a support component and a promoter component with the promoter component being present as a skin of the support. The sorbent is prepared by a process of impregnating a support component with a promoter.
U.S Patent, 6,656,877 discloses an attrition resistant sorbent, prepared by the impregnation of a sorbent support comprising zinc oxide, expanded perlite, and alumina with a promoter such as nickel, nickel oxide or a precursor of nickel oxide followed by reduction of the valence of the promoter.
U.S Patent, 6,482,314 discloses a particulate sorbent compositions comprising a mixture of zinc oxide, silica, alumina and a substantially reduced valence cobalt, prepared by
impregnation method, for the desulfurization of a feed stream of cracked-gasoline or diesel fuels
U.S Patent, 6,429,170 discloses attrition resistant, sorbent compositions for the removal of elemental sulfur and sulfur compounds, such as hydrogen sulfide and organic sulfides, from cracked-gasoline and diesel fuels are prepared by the impregnation of a sorbent support comprising zinc oxide, expanded perlite, and alumina with a promoter such as nickel, nickel oxide or a precursor of nickel oxide followed by reduction of the valence of the promoter metal in the resulting promoter metal sorbent support composition.
U.S Patent, 6,428,685 discloses a particulate sorbent compositions which are suitable for the removal of sulfur from streams of cracked-gasoline or diesel fuel are provided which have increased porosity, improved resistance to deactivation through the addition of a calcium compound selected from the group consisting of calcium sulfate, calcium silicate, calcium phosphate or calcium aluminate to the support system comprised of zinc oxide, silica and alumina having thereon a promoter wherein the promoter is metal, metal oxide or metal oxide precursor.
U.S Patent, 6,346,190 discloses a particulate sorbent compositions consisting essentially of zinc ferrite, nickel and an inorganic binder, wherein the zinc ferrite and nickel of reduced valence, are provided for the desulfurization of a feed stream of cracked-gasoline or diesel
U.S Patent, 6,338,794 discloses a particulate sorbent compositions comprising zinc titanate support having thereon a substantially reduced valence promoter metal selected from the group consisting of cobalt, nickel, iron, manganese, copper, molybdenum, tungsten, silver, tin and vanadium or mixtures thereof provide a system for the desulfurization of a feed stream of cracked-gasolines or diesel fuels.
U.S Patent, 6,274,533 discloses a sorbent system prepared by impregnating a particulate support which comprises zinc oxide and an inorganic or organic carrier with a bimetallic promoter formed from two or more metals selected from the group consisting of nickel, cobalt, iron, manganese, copper, zinc molybdenum, tungsten, silver, tin, antimony and
U.S Patent, 6,274,031 discloses a novel circulatable sorbent material suitable for use in a transport desulfurization system for removing sulfur from a fluid stream containing sulfur and the use thereof in such a transport desulfurization system. The transport desulfurization process utilizes a circulatable particulate material containing alumina, silica, zinc oxide and a metal oxide, which is contacted with a fluid stream and thereafter separated and reused with a portion being regenerated.
U.S Patent, 6,271,173 discloses a particulate sorbent compositions which are suitable for the removal of sulfur from streams of cracked-gasoline or diesel fuel are provided which have increased porosity, improved resistance to deactivation through the addition 6f a calcium compound selected from the group consisting of calcium sulfate, calcium silicate, calcium phosphate or calcium aluminate to the support system comprised of zinc oxide, silica and alumina having thereon a promoter wherein the promoter is metal, metal oxide or metal oxide precursor with the metal being selected from the group consisting of cobalt, nickel, iron, manganese, copper, molybdenum, tungsten, silver, tin and vanadium or mixtures thereof and wherein the valence of such promoter has been substantially reduced
to 2 or less. Process for the preparation of such sorbent systems as well as the use of same for the desulfurization of cracked-gasolines and diesel fuels are also provided.
US Patent, 6,254,766 discloses a particulate sorbent compositions comprising a mixture of zinc oxide, silica, alumina and a substantially reduced valence nickel are provided for the desulfurization of a feed stream of cracked-gasoline or diesel fuels in a desulfurization zone by a process which comprises the contacting of such feed streams in a desulfurization zone followed by separation of the resulting low sulfur-containing stream and sulfurized-sorbent and thereafter regenerating and activating the separated sorbent before recycle of same to the desulfurization zone.
U.S Patent, 6,184,176 discloses a sorbent comprising a mixture of zinc oxide, silica, alumina and substantially reduced valence cobalt provided for the desulfurization of a feed stream of cracked-gasoline or diesel fuels.
U.S Patent, 6,056,871 discloses a novel circulatable sorbent material suitable for use in a transport desulfurization system for removing sulfur from a fluid stream containing sulfur and the use thereof in such a transport desulfurization system. The transport desulfurization process utilizes a circulatable particulate material containing alumina, silica zinc oxide and a metal oxide, which is contacted with a fluid stream and thereafter separated and reused with a portion being regenerated.
The adsorbents reported in the prior art cited above involves the conventional impregnation approaches for loading the active metal components.
The surprising results of the present invention is by achieving enhanced adsorption capacity for the adsorbent composition used for removing most refractory sulfur compounds from refinery streams in a short duration of time and also consuming minimum quantity of hydrogen in the complete process.
OBJECTS OF THE INVENTION:
The main object of the present invention is to design a high adsorption capacity, reactive adsorbents suitable for removal of refractory sulfur compounds from various refinery streams such as naphtha, gasoline, kerosene, jet fuel, diesel fuel and gas oil etc.
An object of the invention is to provide reactive adsorbents composition comprising of base component, spinel oxide and bimetallic alloy for the removal of sulfur compounds from refinery streams..
Another object of the present invention is to design a process for the preparation of reactive adsorbent composition
Still another object of the invention is to provide an alloy component which acts in synergy with base component for enhancing the adsorption capacity of the adsorbent composition.
Yet another object of the invention is to provide reactive adsorbent composition comprising of readily available raw-materials.
Still yet another object of the invention is to provide fixed bed adsorption process to remove sulfur from refinery streams such as gasoline, kerosene, jet fuel, diesel fuel and gas oil etc.
Further object of the invention is to minimize the hydrogen consumption in the process of fixed bed adsorption to remove refractory sulfur compounds from refinery streams such as naphtha, gasoline, kerosene, jet fuel, diesel fuel and gas oil etc.
Still further object of the invention is to provide a process for regeneration of the reactive adsorbent composition after multiple cycles of operations.
SUMMARY OF THE INVENTION:
The present invention relates to a reactive adsorbent composition for removing refractory sulphur compounds from refinery streams, the said composition comprising of base component in the range of 10 to 50 wt%, Spinel oxide in the range of 20 to 60 wt% as reactive metal oxide, bimetallic alloy in the range of 10 to 40 wt% acting as an adsorbent capacity enhancer component in synergy with base component of the said composition. The invention also relates to a process for the preparation of said composition by mixing in solid state fine particles of said components of said composition, homogenizing the mixture thus obtained, peptizing the homogenized solid, extruding the peptized material,, drying the extrudates, further calcining the dried extrudates and reducing the calcined material under hydrogen flow.
DETAILED DESCRIPTION OF THE INVENTION:
In accordance with the objective, the present invention provides a reactive adsorbent composition for removal of refractory sulphur compounds from refinery streams comprising of:
Ingredient W/W(%)
Base component 10.0 to 50.0
Spinel oxide 20.0 to 60.0
Bimetallic alloy 10.0 to 40.0
Wherein the bimetallic alloy act as an adsorption capacity enhancer component in synergy with base component of the said reactive adsorbent composition.
The base component of composition is a porous material selected from a group consisting of alumina, clay, magnesia, titania and mixtures thereof.
The preferable base component of the composition is clay.
The base component clay comprises mainly of titanium oxide, ferric oxide, manganese dioxide and silicon dioxide.
A reactive adsorbent composition having surface area ranging from 50 to 200 m2/gm.
A reactive adsorbent composition having pore volume ranging from 01 to 0.6 cc/gm.
A reactive adsorbent composition having an average pore size ranging from 50 to 200A°.
The spinel oxide of the composition is an oxide of formula AB 2O4, wherein A represents a divalent metal selected from the group consisting of zinc, nickel, magnesium and like metals; B represents a trivalent metal atom selected from the group consisting of aluminium, chromium, gallium, iron and like metals.
The bimetallic alloy of the composition is an alloy of metals selected from the group consisting of nickel, platinum, palladium, titanium like metals and zinc.
The bimetallic alloy used is selected from a group of alloy Nickel zinc oxide, Platinum zinc oxide, Palladium Zinc oxide, Titanium zinc oxide and mixtures thereof.
An embodiment of the invention describes a process for the preparation of reactive adsorbent composition for removing sulphur compounds of refinery streams, the said process comprising steps of:
a) selecting a base component,
b) adding spinel oxide of formula AB2O4, to step (a),
c) obtaining in situ bimetallic alloy by adding metal oxides ,
d) mixing by grinding to fine particles the mixture of step (c) in dry solid form,

e) homogenizing the mixture of step (d) by milling with solvent,
f) peptizing the wet solid of step (c) with dilute acid,
g) extruding the peptized material of step (f) in the presence of extrusion aiding
agents
h) drying the extrudates of step (g) in a furnace at a temperature of about 100°
to200°C, for4tol2hours, i) calcining the dried material of step (h) in a furnace at a temperature ranging
from 200°C to 550°C for a prime peiod of 4 to 12 hours, j) reducing the calcined material of step (i) under hydrogen flow at a
temperature ranging between 250°C to 500°C, and k) obtaining dry reactive adsorbent composition.
The solvent used in the process is selected from a group consisting of water, acetone, propanol and preferably acetone.
The mineral acid used is dilute nitric acid.
The extrusion aiding agents used is selected from a group consisting of polyvinyl alcohols, polyethylene glycols and carboxymethyl cellulose.
Another embodiment of the invention describes a process for removal of refractory sulfur compounds using the reactive adsorbent composition comprising steps of:
a) selecting fixed bed reactor or simulated moving bed reactors comprising of upper, middle and bottom zones,
b) loading the upper and bottom zone with commercial alumina and middle zone with reactive adsorbent composition,
c) activating loaded zones by hydrogen flow at a temperature of about 400°C for a
period of an hour,
d) passing the refinery stream through the reactor maintaining appropriate flow rate, pressure, hydrogen flow and temperature and
e) collecting the treated reactor effluent at regular intervals and analysed for sulphur content.
The process provides removal of refractory sulfur compounds from the refinery stream selected from a group consisting of naphtha, gasoline, jet fuel, kerosene and diesel fraction.
The process involves the pressure ranges from 5 to 30 bar, preferably between 10 to 20 bar hydrogen pressure.
The process utilizes ratio of hydrogen to refinery stream ranges from 10 100 to 600 v/v and preferably 200 to 400 v/v.
The process utilizes a temperature ranging between 150°C to 500°C.
The process wherein liquid hourly space velocity ranges from 0.5/h to 5.0/h and preferably to 1.0/hto2.0/h.
The process wherein the refinery stream used has a boiling point ranging between 35° to 450°C and sulphur content ranging from about 300 ppm to 3000 ppm.
In the context of present invention the term refinery stream relates to commercial liquid hydrocarbon stream of naphtha, gasoline, kerosene, jet fuel, diesel and heavy gas oil streams.
Adsorbent:
Novel high adsorption capacity adsorbent comprising high surface area and porosity were produced by solid-sate reactions. The adsorbents are specially designed to remove the most refractory sulfur compounds even from high final boiling point (FBP) up to about 450 °C. The adsorbents comprised of a base component, a reactive mixed metal oxide component, and adsorption capacity enhancer components.
The base component of adsorbents is a porous material, which provides the porosity, elasticity for extrusion and strength to the said adsorbent. These materials are such as alumina, clay, magnesia, titania or a mixture of two or more of the said base materials, more preferably a clay in the range from about 5 to 35 weight percent and an alumina in the range from about 5 to 20 weight percent. The base component as alumina is a porous gamma alumina having surface area in the range from about 250 to 350 m2/g and having a unimodal pore size distribution. The clay component contains mainly TiO2, Fe2O3, MnO2, and SiO2 obtained from the state of Rajasthan in India. The base clay component also acts as an adsorption enhancer in synergy with the other active components. The base component will generally be present in range from about 10 to 50 weight percent.
The reactive component of adsorbent is a spinel oxide of the form AB2O4 where 'A' is a divalent atom like Zn, Ni, Mg, Mn. Fe and 'B' a trivalent metal atom like Al, etc. The reactive component of the adsorbent was prepared through solid-state reactions of the said metal oxides at the temperature range from about 400 to 650°C. The reactive metal oxide component will generally be present in range from about 20 to 60 weight percent. This component is responsible for detaching the sulfur molecule form the sulfur compound. The reactive metal oxide component will generally be present in range from about 20 to 60 weight percent
The activity enhancer component of the adsorbent is a bimetallic alloy generated in situ from a mixed metal oxide such as oxides of nickel, platinum, palladium etc and Zinc, acts as an adsorption enhancer in synergy with the clay component. The adsorption capacity enhancer metal oxide component will generally be present in range from about 10 to 40 weight percent.
All three components of the adsorbent were mixed in a crucible in dry solid form. The mixture was then grinded in a grinder to generate a powder of fine particles and homogenized by mulling with solvent like water, acetone, and propanol, more preferably with acetone to form a wet solid. The wet solid was then used in an extruder after peptizing with dilute acids preferably with nitric acid and/ or by the addition of extrusion aiding agents like polyvinyl alcohols, polyethylene glycols or carboxyl methyl cellulose. The extrudates of the adsorbents were then dried at room temperature for about overnight followed by drying in a furnace at about 100 to 200 °C temperature for about 4 to 12 hrs. The dried adsorbent was then calcined in a furnace at about 200 to 550 °C temperature for about 4 to 12 hrs.
An optimum temperature and multiple calcinations steps are required to ensure that the active phase is increased.
The final adsorbents comprise surface area ranging from 50 to 200 m2/gm, pore volume ranging from 0.1 to 0.6 cc/gm and average pore size ranging from 50 to 200 A0. The final adsorbent was then reduced in a temperature range from about 250° to 500 °C under hydrogen flow.
After reduction, the adsorbent is used for reducing sulfur content in hydrocarbon fuels such as naphtha, gasoline, jet fuel, and kerosene and diesel fractions. The adsorption process occurs in one or more numbers of fixed bed reactors. The adsorption process was carried out in the temperature range of about 150°C to 500°C, pressure range of about 5 to 30 bar, hydrogen to hydrocarbon ratio in a range of about 100 to 600 v/v, liquid hourly space velocity in the range of 0.5 to 5 h-1
After reaching the optimum level, the adsorbents were regenerated in the temperature range of about 200-500°C in a mixture of air and nitrogen.
The two numbers of adsorbents (A-1 and A-2) have been designed by adding various constituents in different ratios. The details of these adsorbents are reported Table-lc.
Feed Diesel:
The diesel feed stocks used in treating of these feeds have been generated by hydrotreating the high sulfur containing feed (1.0 to 1.5 wt %). The feed contains higher boiling range materials up to about 450 °C. The feed contains higher concentration of most refractory sulfur compounds such as 4 or 6-MDBT, 4,6-DMDBT, and other alkyl DBTs due to higher boiling range material in the feed stream. The details of the diesel feed stocks are reported in Table-la/lb.
(Table Removed)
Experimental Setup:
The experiments were conducted in a hydro processing pilot plant. The details of the pilot plant are shown in Figure-1. This pilot plant contains two numbers of fixed bed reactors, which can be operated either one at a time or both reactors in series. These reactors are equipped with separate electrical furnaces, which can heat the reactors up to 600 °C. The furnace is divided into five different zones. The top zone is used for preheating the feed stream before entering the process zones. The middle three zones are used for process reactions and bottom zone is used for post heating purposes. Adjusting the corresponding skin temperatures controls the reactor internal temperatures. The feed was charged into a feed tank (T-l), which can preheat the feedstock up to about 150 °C. The feed was then pumped through a diaphragm pump (P-1). Three numbers of Mass Flow Controllers each for measurement of hydrogen, nitrogen and air are equipped in the inlet of the reactors. In the adsorption step, the liquid and gas streams join together and enter into the reactors in down flow mode. The isothermal temperature profile was maintained throughout the adsorption zone. The reactor effluent stream then enters to Separator (S-l), where gas and liquid streams were separated. The gas stream exit from the top of the separator and sent to vent via a pressure control valve (PV-1) and wet gas meter (FQI-1). The liquid strean exit from the bottom of the separator and collected in product tank (T-2) through a level control valve (LV-1)). The hydrocarbon feed and reactor effluent samples were analyzed for total sulfur content by Sulphur-Nitrogen Analyzer (Antek) and sulphur compound class by GC-SCD.
(Figure Removed)
Regeneration of the Adsorbents:
The regeneration of adsorbents was completed in three steps. In the first step, adsorbed hydrocarbons were stripped with nitrogen. In the second step, the adsorbed sulphur on the adsorbent was burnt with nitrogen and air mixture followed by post stripping with nitrogen to replace the residual of air. In the third step, the adsorbent was activated by hydrogen at 400 °C for about 1 to 2 hrs. After regeneration, the adsorbent was ready for reuse.
The study is further explained with examples of treating various diesel feedstocks of different sulfur contents ranging from 65 to 500 ppm. The experiments are performed at different operating conditions e.g. temperatures ranging from ambient to 400 °C, pressure ranging from 10 to 20 bar, hydrogen to hydrocarbon ratio flow ranging from 10 to 50, and LHSV ranging from 0.5 to 2.0 per hour.
Examples: Example-1: Preparation of Reactive Adsorbent Composition(s)
1. Two reactive adsorbent composition(s) (A-l & A-2) were prepared by solid-sate mixing of zinc nickel aluminate, zinc nickel oxide, Rajasthan clay and alumina in different proportions.
2. Zinc nickel aluminate was prepared through the solid-state reaction of zinc oxide, nickel oxide and alumina at a temperature of about 550 - 600°C. The nickel nitrate hexahydrate was used to get the nickel oxide
3. The zinc nickel oxide was prepared through the solid-state reaction of zinc oxide, and nickel oxide at a temperature of about 500- 600°C .The nickel nitrate hexahydrate was used to get the nickel oxide
4. The various components prepared above were mixed in the desired proportions in a crucible and ground intermittently using acetone for homogenization of the solid and dried.
5. The dried powder was extruded after peptizing with about 1% nitric acid to form the cylindrical pellets. The pellets were then dried at a room temperature of about 30 °C for overnight followed by drying at a temperature of about 120 °C for about 4-12 hours.
6. The dried adsorbent is then calcined at a temperature of about 600 °C for about 4-12 hours
7. Two reactive adsorbent compositions A-l and A-2 were prepared as per above prescribed method. The details of composition and characteristic properties of reactive Adsorbents are listed in Table-lc.
Table-lc Composition and Characterization of Adsorbents

(Table Removed)
ExampIe-2: Treatment of Diesel Feed-1 with Alumina
In this experiment commercially available alumina (400 gms) of balls size ranging from 3 to 5 mm dia were loaded in a fixed bed reactor that has an internal diameter of 25 mm and length of 1100 mm. Activation was performed by hydrogen at 400 °C for about one hour. Diesel Feed-1 containing 500-ppm sulfur was passed through the reactor at the rate of 65 gm/hr in down flow mode. The reactor pressure of 10 bar and hydrogen flow of 10 SLPH was maintained during the experiment. The treated reactor effluent samples were collected at regular intervals and analyzed for sulfur content by Sulfur-Nitrogen Analyzer. The results obtained are shown in TabIe-2 and Figure-2.
TabIe-2 Desulfurization of Diesel Feed-1 with Alumina
(Table Removed)
Example-3: Treatment of Diesel Feed-1 with Fresh Adsorbent A-1
In this experiment commercially available alumina of balls of size ranging from 3 to 5 mm dia were loaded in the top and bottom zone of the fixed bed reactor. The 60 gm of adsorbent A-1 was loaded in middle zone of the reactor. All other conditions were remaining unchanged as mentioned in example-1. The results obtained are shown in Table-3 and Figure-3.
TabIe-3 Desulfurization of Diesel Feed-1 with Fresh Adsorbent A-1

(Table Removed)
ig-3: Treatment of Diesel Feed-1 with Fresh Adsorbent

(Table Removed)
Example-4: Treatment of Diesel Feed-2 with Regenerated (Regeneration-1) Adsorbent A-l
The adsorbent used in example-2 was regenerated (Regeneration-1) with nitrogen and / air
mixture as per previously described method. The Feed was also changed to Feed-2, which
contains 400-ppm sulfur. The adsorption was performed at lower operating temperature of
200 °C and higher feed rate of 180 gm/hr. The results obtained are shown in Table-4 and
Figure-4.
Table-4 Desulfurization of Diesel Feed-2 with Regenerated Adsorbent (Regeneration-1) A-l

(Table Removed)
ig-4: Treatment of Diesel Feed-1 with Regerated Adsorbent

(Figure Removed)
ExampIe-5: Treatment of Diesel Feed-2 with Regenerated (Regeneration-2) Adsorbent A-l
The adsorbent used in example-3 was further regenerated (Regeneration-2). The adsorption was performed with Feed-2 at ambient operating temperature of 30 °C and higher feed rate of 180 gm/hr. The results obtained are shown in Table-5 and Figure-5
Table-5: Desulfurization of Diesel Feed-2 with Regenerated (Regeneration-2) Adsorbent A-l

(Table Removed)
Example-6: Treatment of Diesel Feed-3 with Regenerated (Regeneration-3) Adsorbent A-1
The adsorbent used in example-4 was further regenerated (Regeneration-3). The Feed was also changed to Feed-3 which contains 350 ppm sulfur i.e. lower than Feed-2. The adsorption was performed at 300 °C temperature and feed rate of 65 gm/hr. The results obtained are shown in Table-6 and Figure-6.
Table-6: Desulfurization of Diesel Feed-3 with Regenerated (Regeneration-3) Adsorbent A-1

Fig-6: Treatment of Diesel Feed-3 with Adsorbent
(Table Removed)
ExampIe-7: Treatment of Diesel Feed-4 with Regenerated (Regeneration-4) Adsorbent A-l
The adsorbent used in example-5 was further regenerated (Regeneration-4). The Feed was also changed to Feed-4 which contains 260 ppm sulfur i.e. lower than Feed-3. The adsorption was performed at 400 °C temperature and feed rate of 65 gm/hr. The results obtained are shown in Table-7 and Figure-7.
Table-7: Desulfurization of Diesel Feed-4 with Regenerated (Regeneration-4) Adsorbent A-l

(Table Removed)
Fig-7: Treatment of Diesel Feed-4 with Adsorbent
(Table Removed)
ExampIe-8: Treatment of Diesel Feed-5 with Adsorbent A-2
The adsorbent A-2 was prepared by changing the proportions of various constituents. The adsorbent A-2 comprised more surface area and pore volume in comparison to adsorbent A-1. The Feed-5, which contains 65-ppm sulfur, was used for this experiment. The adsorption was performed at 400 °C temperature and feed rate of 40 gm/hr. The results obtained are shown in Table-8 and Figure-8.
Table-8: Desulfurization of Diesel Feed-5 with Adsorbent A-2

(Table Removed)

Fig-8 Treatment of Diesel Feed

-5 with Adsorbent-2
(Formula Removed)
ExampIe-9: Treatment of Diesel Feed-3 with Regenerated (Regeneration -1) Adsorbent A-2
The adsorbent A-2 used in previous experiment was regenerated. The Feed-3, which contains 350-ppm sulfur, was used for this experiment. The detailed data of GC-SCD of this feed is reported in Table-lb. The adsorption was performed at 400 °C temperature and feed rate of 40 gm/hr. The results obtained are shown in Table-9 and Figure-9. The detailed GC-SCD was performed for Feed-3 (Table-lb) and various product samples collected at regular intervals (Table-lOa to Table-lOd). To identify the various sulfur compounds, GC-SCD of standard sulfur compounds (BT, DBT, 4-MDBT and 4,6-DMDBT) was performed and other sulphur compounds were detected by referring to the relative retention times available in literature reported by Ma et. al. (1994, 1998). The GC-SCD chromatograms of Feed-3 and product samples are shown in Figure-10. It is observed from the results shown in Tables 10a-10d7&ll and Figure-11 to Figure-13 that 4,6 DMDBT, C2DBT-6, C3DBT-3, C3DBT-4 & C4DBT-3 are most refractive sulphur compounds. Selectivity of desulfurization of various sulphur compounds are shown in Figure-12. Selectivity of desulfurization of most refractive sulphur compounds are shown in Figure-13.
Table-9: Desulfurization of Diesel Feed-3 with Regenerated Adsorbent A-2

(Table Removed)

Fig-10: GC-SCD Chromatograms of Feed and Products

(Figure Removed)
E/Accumulative wt of Feed Treated/Unit wt. of Adsorbent

(Table Removed)
Fig. 12 : Desulphurization of Feed-3 with A2
(Figure Removed)
Fig. 13: Desulphurization of most refractive'S' Compound
(Figure Removed)
REFERENCES CITED:
1. Hernandez-Maldonado et al., Desulfurization of Transportation Fuels by Adsorption, Catalysis Reviews, Vol. 46, No. 2, pp. 111-150, 2004
2. Whitehurst et al., Present state of the art and future challenges in the hydrodesulfurization of polyaromatic sulfur compounds, Adv. Catal., 42 (1998) 345-471.
3. Avidan et al., National Petroleum & Refiner Assoc. Annual Meeting. Washington, D.C., March 2001, Paper AM-01-55
4. Parkinson et al., Diesel desulfurization puts refiners in a quandary, Chem. Eng., 108 (2), (2001) 37-41.
5. Song et al., Deep desulfurization of hydrocarbon fuels, US Patent Publication No.2004/0007506, Jan. 15, 2004.
6. Song et al., A new approach to deep desulfurization of gasoline, diesel fuel and jet fuel by selective adsorption for ultra-clean fuels and for fuel cell applications, Catalysis Today 77 (2002) 107-116
7. Dodwell et. al., Desulfurization and novel sorbents for same, US Patent Publication No. US 2003/0032555 Al, Feb. 13,2003.
8. Weston et al., Catalyst adsorbent for removal of sulfur compounds for fuel cells, US Patent Publication No.2004/0063576, Apr. 1, 2004.
9. Khare et. al., Desulfurization and novel sorbent for same, U.S. Patent 6,803,343, Oct. 12, 2004
10. Khare et. al., Desulfurization and novel sorbent for same, U.S. Patent 6,683,024, Jan. 27, 2004
11.Sughrue et. al., Desulfurization and sorbents for same, U.S. Patent 6,656,877, Dec. 2, 2003
12. Khare et. al., Desulfurization for cracked gasoline or diesel fuel, U.S. Patent 6,482,314, Nov. 19,2002
13. Dodwell et al., Sorbents for desulfurizing gasolines and diesel fuel, U.S. Patent U.S Patent, 6,429,170, Aug. 6, 2002
14. Khare et. al., Desulfurization and novel sorbents for same, U.S Patent, 6,428,685, Aug. 6, 2002
15. Khare et. al., Desulfurization and novel sorbents for same, U.S Patent, 6,346,190, Feb. 12,2002
16. Khare et. al., Desulfurization with zinc titanate, U.S Patent, 6,338,794 Jan. 15, 2002
17. Khare et. al.), Desulfurization process and novel bimetallic sorbent systems for same, U.S Patent, 6,274,533, Aug. 14, 2001
18. Khare et. al., Transport desulfurization process utilizing a sulfur sorbent, U.S Patent, 6,274,031, Aug. 14,2001
19. Khare et. al., Process for producing a desulfurization sorbent, U.S Patent, 6,271,173, Aug. 7, 2001
20. Sughrue et. al., Desulfurization and novel sorbents for same, U.S Patent, 6,254,766 , Jul. 3, 2001
21. Khare et. al., Process for the production of a sulfur sorbent, U.S. Patent 6,184,176, Feb. 6, 2001
22. Khare et. al., Transport desulfurization process utilizing a sulfur sorbent, U.S Patent, 6,056,871, May. 2, 2000
23. Ma et al., Hydrodesulfiinzation reactivities of various sulfur compounds in diesel fuels, Ind. Eng. Chem. Res. 1996, 35, 2487-2494
24. Ma et al., Hydrodesulfiinzation reactivities of various sulfur compounds in diesel fuels, Ind. Eng. Chem. Res. 1994, 33, 218 -222

I/We Claim:
1. A reactive adsorbent composition for removal of refractory sulphur
compounds from refinery streams comprising of-
Ingredient W/W(%)
Base component 10.0 to 50.0
Spinel oxide/ 20.0 to 60.0
Bimetallic alloy 10.0 to 40.0
Wherein the bimetallic alloy act as an adsorption capacity enhancer component in synergy with base component of the said reactive adsorbent composition.
2. A composition of claim 1, wherein the base component is a porous material selected from a group consisting of alumina, clay, magnesia, titania and mixtures thereof.
3. A composition of claim 2, wherein the preferable base component is clay.
4. A clay of claim 3 comprises mainly of titanium oxide, ferric oxide, manganese dioxide and silicon dioxide.
5. A reactive adsorbent composition of claim 1 having surface area ranging from 50 to 200 m2/gm.
6. A reactive adsorbent composition of claim 1, having pore volume ranging from 01 to 0.6 cc/gm.
7. A reactive adsorbent composition of claim 1, having an average pore size ranging from 50 to 200A°.
8. A composition of claim 1, wherein the spinel oxide is an oxide of formula AB 2O4, wherein A represents a divalent metal selected from the group consisting of zinc, nickel, magnesium and like metals; B represents a trivalent metal atom selected from the group consisting of aluminium, chromium, gallium, iron and like metals.
9. A composition of claim 1, wherein the bimetallic alloy is an alloy of metals selected from the group consisting of nickel, platinum, palladium, titanium like metals and zinc.

10. A composition of claim 9, wherein the bimetallic alloy used is selected from a group of alloy Nickel zinc oxide, Platinum zinc oxide, Palladium Zinc oxide, Titanium zinc oxide and mixtures thereof.
11. A process for the preparation of reactive adsorbent of claim 1, the said process
comprising steps of:
a) selecting a base component,
b) adding spinel oxide of formula AB2O4, to step (a),
c) obtaining in situ bimetallic alloy by adding metal oxides ,
d) mixing by grinding to fine particles the mixture of step (c) in dry solid form,
e) homogenizing the mixture of step (d) by milling with solvent,
f) peptizing the wet solid of step (c) with dilute acid,
g) extruding the peptized material of step (f) in the presence of extrusion aiding agents
h) drying the extrudates of step (g) in a furnace at a temperature of about
100° to 200°C, for 4 to 12 hours,
i) calcining the dried material of step (h) in a furnace at a temperature
ranging from 200°C to 550°C for a prime period of 4 to 12 hours,
j) reducing the calcined material of step (iO) under hydrogen flow at a
temperature ranging between 250°C to 500°C, and k) obtaining dried reactive adsorbent composition.
12 A process of claim 12, wherein in step (e) the solvent is selected from a group consisting of water, acetone, propanol and preferably acetone.
13 A process of claim 12, wherein in step (f) the mineral acid used is dilute nitric acid.
14 A process of claim 12, wherein in step (g) the extrusion aiding agents is selected from a group consisting of polyvinyl alcohols, polyethylene glycols and carboxymethyl cellulose.
15 A reactive adsorbent composition of claim 1 for removal of sulphur compounds from various refinery streams by a process comprising steps of:
a) selecting fixed bed reactor or simulated moving bed reactors comprising of
upper, middle and bottom zones,
b) loading the upper and bottom zone with commercial alumina and middle zone
with reactive adsorbent composition,
c) activating loaded zones by hydrogen flow at a temperature of about 400°C for a
period of an hour,
d) passing the refinery stream through the reactor maintaining appropriate flow
rate, pressure, hydrogen flow and temperature and
f) collecting the treated reactor effluent at regular intervals and analysed for sulphur content.
16 A process of claim 15, wherein in step (d) the refinery stream treated is selected
from a group consisting of naphtha, gasoline, jet fuel, kereosene and diesel
fraction.
17 The process of claim 15, wherein the step (d) the pressure maintained ranges from
5 to 30 bar, preferably between 10 to 20 bar hydrogen pressure.
18 A process of claim 15, wherein in step(d) the ratio of hydrogen to refinery stream ranges from 10 100 to 600 v/v and preferably 200 to 400 v/v.
19 A process of claim 15, wherein in step (d) the temperature ranges between 150°C to 500°C.
20 A process of claim 15, wherein liquid hourly space velocity ranges from 0.5/h to 5.0/h and preferably to 1.0/h to 2.0/h.
21 A process of claim 16, wherein the refinery stream used has a boiling point 35° (Is
it OK?) to 450°C and sulphur content ranging from about 300 ppm to 3000 ppm.
22 A reactive adsorbent composition, its process of preparation and its use in
removing the sulfur compounds from various refinery streams as herein described
in detail with reference to examples.