CN1460546A - Preparation method fo cobalt zirconium Fischer-Tropsch synthesis catalyst - Google Patents

Abstract

The present invention adopts the coprecipitation method to prepare zirconium oxide carrier, and prepares cobalt nitrate solution with a certain concentration, uses pH meter to regulate pH value of solution in a certain range, and utilizes the isochloric impregnation method to make the active component cobalt be loaded no the surface of zirconium oxide, then adopts the processes of ageing, drying and roasting so as to obtain the invented loaded cobalt-zirconium catalyst with higher activity and selectivity.

Description

A kind of preparation method of cobalt zirconium fischer-tropsch synthetic catalyst

Technical field:

The invention belongs to a kind of preparation method of fischer-tropsch synthetic catalyst, relate in particular to a kind of preparation method of cobalt zirconium fischer-tropsch synthetic catalyst.

Background technology:

Fischer-Tropsch synthetic (it is synthetic to be called for short F-T) is the important channel that coal and conversion of natural gas are produced liquid fuel.The energy characteristics of China is that the few oil of rich coal has gas, and exploitation is had important practical significance by the process that coal/natural gas via synthesis gas is converted into liquid fuel, and makes this process realize that the key of industrial mass production is the development and the exploitation of effective catalyst.The common carrier SiO of cobalt-base catalyst ₂, Al ₂O ₃, TiO ₂Form the compound of difficult reduction (as CoAl Deng easy and active component ₂O ₄, CoSiO ₄, CoTiO ₃) the active component utilization rate is reduced.How to improve the utilization rate of active component, reducing methane selectively is the common difficult problem of present F-T synthetic reaction.Can reduce cobalt and carrier interactions to a certain extent by adding catalyst promoter and carrier surface being carried out chemical modification, but can not tackle the problem at its root.The research of making catalyst carrier, catalyst and catalyst promoter with zirconia has in recent years caused the common concern of vast researcher, zirconia not it is advantageous that as catalyst carrier and generates difficult reducing compound with cobalt, have high reaction activity and high and stability, can satisfy the requirement of industrial large-scale industrial production.

The development of cobalt-base catalyst at present mainly concentrates on conventional carriers SiO with exploitation ₂, TiO ₂, Al ₂O ₃On, and zirconia is less as the research of fischer-tropsch synthetic catalyst carrier.(J.Catal.2O02,205:346) grade has been reported a kind of Co/ZrO to D.I Enache ₂Catalyst, it consists of 10%Co:90%ZrO ₂, but it is active and selectivity is relatively poor.How existing patent documentation is by adding precious metal to improve activity of such catalysts and selectivity.Because the interpolation of precious metal additive makes and the cost increase of catalyst has limited Study of Catalyst and exploitation.

Summary of the invention: the purpose of this invention is to provide a kind of activity and selectivity height, the preparation method of the cobalt zirconium fischer-tropsch synthetic catalyst that cost is low.

Preparation method of the present invention comprises the steps:

With ZrOCl ₂8H ₂O solution and ammoniacal liquor also flow co-precipitation, make Zirconia carrier; The pH value of regulating cobalt nitrate solution with nitric acid or urea liquid adds the cobalt nitrate solution that configures in the Zirconia carrier between 0.8-8, floods, aging 6-150 hour, dried by the fire 8-16 hour down at 100-150 ℃,, make catalyst then at 300-600 ℃ of following roasting 2-10 hour;

Wherein the weight percentage of cobalt is 5-35% in the catalyst, and zirconic weight percentage is 65-95%.

Application of Catalyst condition of the present invention is: utilize pure hydrogen at 300-500 ℃ of in-situ reducing, reaction temperature 190-260 ℃, reaction pressure 1.0-5.0Mpa, air speed 500-3000h ^-1, unstripped gas proportioning H ₂/ CO=1: 10-10: 1.Advantage of the present invention is as follows:

Compare with the cobalt-base catalyst of conventional carriers (as: silica gel, aluminium oxide, titanium oxide etc.) load, this catalyst has higher activity and selectivity, and cost is low; This method preparation is simple, easy to operate.

The specific embodiment:

Embodiment 1: the ammoniacal liquor with 12% is added drop-wise to the ZrOCl that concentration is 0.3mol/l in 50 ℃ ₂8H ₂In the O solution, rate of addition per minute 1ml.Preparation process control pH value is 10, and aging 2 hours, filtration washing was to there not being Cl ^-1, 120 ℃ of dryings 24 hours, 500 ℃ of roastings made Zirconia carrier in 6 hours.Take by weighing the 11g Zirconia carrier, drip distilled water, write down the volume 5ml of consume water to just moistening.By final catalyst cobalt content 10wt%, take by weighing the 6.1g cobalt nitrate, the water-soluble 5ml solution that is made into, with nitric acid regulator solution pH value to 0.8, the above-mentioned cobalt nitrate solution that configures is all joined in the 11g zirconia dipping, aging 6 hours, 400 ℃ of roastings made catalyst Z1 in 6 hours.The evaluating catalyst experiment is in pressurization static bed reactor, and with pure hydrogen temperature programmed reduction, the cooling back is switched synthesis gas and reacted.Reaction effluent is collected by hot trap, cold-trap respectively.Reaction condition is 180-230 ℃, 1000h ^-1, 2.0MPa, H ₂/ CO ≈ 2.The result is as shown in table 1 for Z1 catalyst Fischer-Tropsch synthesis.

Embodiment 2: the preparation of Zirconia carrier is with embodiment 1.Take by weighing the 8.4g Zirconia carrier, by final catalyst cobalt content 20wt%, take by weighing the 9.32g cobalt nitrate, the water-soluble 4ml solution that is made into, with nitric acid regulator solution pH value to 1.5, the above-mentioned cobalt nitrate solution that configures is all joined in the 8.4g zirconia dipping, aging 24 hours, 300 ℃ of roastings made catalyst Z2 in 10 hours.Catalyst activity evaluation experimental condition is with embodiment 1.The result is as shown in table 1 for Z2 catalyst Fischer-Tropsch synthesis.

Embodiment 3: the preparation of Zirconia carrier is with embodiment 1.Take by weighing the 6.3g Zirconia carrier, by final catalyst cobalt content 15wt%, take by weighing the 5.55g cobalt nitrate, the water-soluble 3ml solution that is made into, with nitric acid regulator solution pH value to 2.5, the above-mentioned cobalt nitrate solution that configures is all joined in the 6.3g zirconia dipping, aging 48 hours, 350 ℃ of roastings made catalyst Z3 in 8 hours.Catalyst activity evaluation experimental condition is with embodiment 1.The result is as shown in table 1 for Z3 catalyst Fischer-Tropsch synthesis.

Embodiment 4: the preparation of Zirconia carrier is with embodiment 1.Take by weighing the 11.5g Zirconia carrier, by final catalyst cobalt content 30wt%, take by weighing the 19.14g cobalt nitrate, the water-soluble 6ml solution that is made into, with nitric acid regulator solution pH value to 4, the above-mentioned cobalt nitrate solution that configures is all joined in the 11.5g zirconia dipping, aging 96 hours, 450 ℃ of roastings made catalyst Z4 in 7 hours.Catalyst activity evaluation experimental condition is with embodiment 1.The result is as shown in table 1 for Z4 catalyst Fischer-Tropsch synthesis.

Embodiment 5: the preparation of Zirconia carrier is with embodiment 1.Take by weighing the 6.3g Zirconia carrier, by final catalyst cobalt content 5wt%, take by weighing the 1.65g cobalt nitrate, the water-soluble 2.5ml solution that is made into, with urea regulator solution pH value to 5, the above-mentioned cobalt nitrate solution that configures is all joined in the 6.3g zirconia dipping, aging 130 hours, 550 ℃ of roastings made catalyst Z5 in 3 hours.Catalyst activity evaluation experimental condition is with embodiment 1.The result is as shown in table 1 for Z5 catalyst Fischer-Tropsch synthesis.

Embodiment 6: the preparation of Zirconia carrier is with embodiment 1.Take by weighing the 12.6g Zirconia carrier, by final catalyst cobalt content 35wt%, take by weighing the 23.1g cobalt nitrate, the water-soluble 6ml solution that is made into, with urea regulator solution pH value to 6, the above-mentioned cobalt nitrate solution that configures is all joined in the 12.6g zirconia dipping, aging 150 hours, 600 ℃ of roastings made catalyst Z6 in 2 hours.Catalyst activity evaluation experimental condition is with embodiment 1.The result is as shown in table 1 for Z6 catalyst Fischer-Tropsch synthesis.

Embodiment 7: the preparation of Zirconia carrier is with embodiment 1.Take by weighing the 13.2g Zirconia carrier, by final catalyst cobalt content 10wt%, take by weighing the 7.32g cobalt nitrate, the water-soluble 7ml solution that is made into, with urea regulator solution pH value to 7, the above-mentioned cobalt nitrate solution that configures is all joined in the 13.2g zirconia dipping, aging 12 hours, 400 ℃ of roastings made catalyst Z7 in 6 hours.Catalyst activity evaluation experimental condition is with embodiment 1.The result is as shown in table 1 for Z7 catalyst Fischer-Tropsch synthesis.

Embodiment 8: the preparation of Zirconia carrier is with embodiment 1.Take by weighing the 11g Zirconia carrier, by final catalyst cobalt content 20wt%, take by weighing the 12.2g cobalt nitrate, the water-soluble 5ml solution that is made into, with urea regulator solution pH value to 8, the above-mentioned cobalt nitrate solution that configures is all joined in the 11g zirconia dipping, aging 36 hours, 350 ℃ of roastings made catalyst Z8 in 8 hours.Catalyst activity evaluation experimental condition is with embodiment 1.The result is as shown in table 1 for Z8 catalyst Fischer-Tropsch synthesis.

The reactivity worth of table 1 catalyst

Catalyst	??T/℃	CO conversion ratio (%)	??C 5 +The hydrocarbon yield a	Hydrocarbon products is formed (wt%)
							?????C 1	????C 2-4	????C 5 +
				????Z1	????210	?????84.2				?????136	????6.8	????6.9	????86.3
????220	?????90.1	?????138	????6.0				????8.3	????85.7
					????Z2	????210			?????86.3	?????128	????8.8	????5.0	????86.2
????220	?????89.8	?????132	????7.5	????6.4			????86.1
						????Z3		????210	?????89.2	?????140	????6.2	????7.5	????86.3
????220	?????95.3	?????145	????5.8	????7.4	????86.8
							????Z4	????210	?????90.0	?????138	????6.4	????4.8	????88.8
????220	?????92.3	?????142	????6.2	????5.2	????88.6
						????Z5		????210	?????89.5	?????136	????6.5	????6.0	????87.5
????220	?????90.6	?????140	????5.8	????5.6	????88.6
							????Z6	????210	?????88.2	?????134	????9.0	????5.3	????85.7
????220	?????94.2	?????143	????10.5	????3.5	????86
						????Z7		????210	?????83.6	?????128	????6.9	????7.3	????85.8
????220	?????87.5	?????135	????8.0	????6.0	????86.0
							????Z8	????210	?????82.5	?????130	????6.8	????6.2	????87.0
????220	?????89.3	?????132	????9.3	????7.4	????83.2

A:C ₅ ⁺The C that the hydrocarbon yield obtains when referring on the catalyst whenever by 1 standard cubic meter synthesis gas ₅ ⁺The weight of hydrocarbon (g)

Claims (1)

1. the preparation method of a cobalt zirconium fischer-tropsch synthetic catalyst is characterized in that comprising the steps:

With ZrOCl ₂8H ₂O solution and ammoniacal liquor also flow co-precipitation, make Zirconia carrier; The pH value of regulating cobalt nitrate solution with nitric acid or urea liquid adds the cobalt nitrate solution that configures in the Zirconia carrier between 0.8-8, floods, aging 6-150 hour, dried by the fire 8-16 hour down at 100-150 ℃,, make catalyst then at 300-600 ℃ of following roasting 2-10 hour;

Wherein the weight percentage of cobalt is 5-35% in the catalyst, and zirconic weight percentage is 65-95%.