CN102909086A

CN102909086A - Catalyst granule for synthesis ammonia

Info

Publication number: CN102909086A
Application number: CN201210386281XA
Authority: CN
Inventors: 王翀; 李兴扬
Original assignee: Anhui Polytechnic University
Current assignee: Anhui Polytechnic University
Priority date: 2012-10-13
Filing date: 2012-10-13
Publication date: 2013-02-06

Abstract

A solid catalyst particle used in ammonia synthesis reaction, the cross-sectional outline of the particle is in the shape of a continuous, smooth seven-tooth gear, and the catalyst particle has higher heat and pressure resistance.

Description

A kind of synthetic ammonia catalyst particle

Technical field

The present invention relates to the solid catalyst particle that uses in a kind of ammonia synthesis reaction, be specifically related to the synthetic ammonia catalyst particle that a kind of main body is seven gear-like.

Background technology

Synthetic ammonia is important industrial chemicals, is mainly used to produce chemical fertilizer, nitric acid, ammonium salt, soda ash etc.As one of pillar industry of chemical industry, synthetic ammonia is the industry of a high energy consumption, poor benefit.Ammonia synthesis reaction is the process that a reversible heat release and gas volume dwindle, and considers from thermodynamics, reach or near equilibrium conversion, and catalytic reaction should be carried out under lower temperature and higher pressure.Yet the reduction of temperature can make reaction rate descend, and the raising of pressure can make again energy consumption greatly increase.The catalyst that mostly is greatly iron system that uses in the ammonia synthesis reaction now, operating temperature and pressure are all higher, and Large Scale Synthetic Ammonia Plants is normally at 400 ℃～500 ℃ and 20.0MPa～30.0MPa.The operating condition of this harshness is very high to the requirement of mechanical strength of solid catalyst particle, in case because the destroy integrity of catalyst granules will cause catalytic activity to reduce.Therefore the intensity that improves Iron Catalyst of Ammonia Synthesis is conducive to improve the stability of synthetic ammonia workshop section.

Summary of the invention

The technical problem that mainly solves among the present invention is to obtain a kind of high-intensity catalyst granules that has, with can be under the synthetic ammonia operating mode withstand high temperatures high pressure.Under hot conditions, catalyst granules can owing to expanded by heating, in the place of stress raisers, can be easy to break.According to mechanics principle, reduce the concentrated method of stress is to make the monnolithic case of member realize rounding off as far as possible.For this reason, the outer contour of the radial cross-section of catalyst granules main body is continuous, the smooth gear shape that is joined end to end and formed by the tangent minor arc of multistage among the present invention.According to the rule of in the higher mathematics smooth curve being judged, because the characteristic function of the curve of shape has the continuous derivative of single order like this, so be smooth curve.That is to say, the outer contour of catalyst granules cross section is smooth curve among the present invention.Having the frictional force of the in theory minimum except circle and minimum stress on such outer contour concentrates; And with respect to common cylinder, this gear-like of catalyst granules has higher specific area among the present invention.

Concrete technical scheme of the present invention comprises:

A kind of solid catalyst particle of gear-like, main body axial component are highly for H, and the radial cross-section outer contour of catalyst granules is continuous, smooth seven gear shapes, and the circumradius of outer contour is R, and inscribed circle radius is r.

Form above-mentioned catalyst granules main body radial cross-section continuous smooth gear-like outer contour be the curved section (as shown in Figure 1) with following feature: one group of quantity is 7, radius is the circle of β, around central point O, circular array in 0 ° to 360 ° scope; Do following three circles, be that (center of circle among Fig. 1 is O for the inscribed circle of outer contour, radius is the circle of r), and the circumcircle (such as the round S among Fig. 1) of 2 adjacent radiuses circle (such as the round P among Fig. 1 and circle Q) that is β, obtain another and organize quantity and be all 7 circle; Respectively from this circle of two groups, mutually circumscribed (mutually circumscribed with circle S such as circle P among Fig. 1 between any two, circle S is mutually circumscribed with circle Q), each circle is upper to form corresponding 2 point of contacts (such as the some A on the circle P among Fig. 1 and some B, some B on the circle S and some C), get the minor arc between these two point of contacts, these all minor arcs join end to end and consist of this continuously outer contour of smooth gear-like of cross section.

The various relevant parameters of above-mentioned formation catalyst particles grain character are of a size of:

R?=?3?mm?~5mm；

r?=?0.8R；

H?=?2R?~?2.2R；

β?=?0.2R。

The present invention compared with prior art, outline is smooth continuously, local stress is little, when improving the catalyst granules specific area, has more significantly improved the intensity of catalyst granules.

Description of drawings

Fig. 1 is that catalyst granules cross section outer contour of the present invention forms schematic diagram.

Fig. 2 is the embodiment of the invention 1 cross section outer contour schematic diagram (also being the cross section outer contour schematic diagram of embodiment 2 and embodiment 3 simultaneously).

The specific embodiment

Below in conjunction with drawings and Examples the present invention is further detailed:

Compared with prior art, the marked improvement of technical solution of the present invention has been to improve the intensity of catalyst granules, and intensity can be investigated by this index of wear rate.Adopt the small-sized seed-coating machine of BY-300A type that Shanghai Huanghai Sea medicine inspection Instr Ltd. produces (stainless steel coating pan diameter 200 mm processed, the coating pan inclination angle is 35 to spend) during the wear rate of specimen particle.During test, every kind of sample is randomly drawed 200, puts into coating pan, the coating pan rotating speed is controlled to be 60 rev/mins, keeps rotating speed to stop after 1 hour, takes out particle, the particle number W that the reading contour structures is complete, meter abrasion of particles rate ω=[(200-W)/200] * 100%.

Related catalyst granules of the present invention all is according to these particles architectural feature separately in the specific embodiment, adopts same material and facility to prepare.

The following examples only are used for the present invention that explains in detail, and limit the scope of the invention never in any form.

Embodiment 1

The cross sectional representation of catalyst granules such as Fig. 2 in the present embodiment, the design parameter size sees Table 1.Catalyst granules body height H=11 mm.The circumradius R of catalyst granules radial cross-section outer contour=5 mm, inscribed circle radius r=4 mm, radius β=1mm.This catalyst granules wear rate ω is 9.5%.

Embodiment 2

The cross sectional representation of catalyst granules such as Fig. 2 in the present embodiment, the design parameter size sees Table 1.Catalyst granules body height H=6.3 mm.The circumradius R of catalyst granules radial cross-section outer contour=3 mm, inscribed circle radius r=2.4 mm, radius β=0.6 mm.This catalyst granules wear rate ω is 7.5%.

Embodiment 3

The cross sectional representation of catalyst granules such as Fig. 2 in the present embodiment, the design parameter size sees Table 1.Catalyst granules body height H=8 mm.The circumradius R of catalyst granules radial cross-section outer contour=4 mm, inscribed circle radius r=3.2 mm, radius β=0.8 mm.This catalyst granules wear rate ω is 9%.

Table 1

?	H (mm)	R (mm)	r (mm)	β (mm)	ω %
						Embodiment 1	11	5	4	1	9.5
Embodiment 2	6.3	3	2.4	0.6	7.5
						Embodiment 3	8	4	3.2	0.8	9

Claims

1. A solid catalyst particle used in the synthetic ammonia reaction, characterized in that the radial cross-sectional outer contour of the catalyst particle is a continuous, smooth seven-tooth gear shape, and the circumscribed circle radius of the outer contour is (R) , the radius of the inscribed circle is (r).

2. The catalyst particle as claimed in claim 1, characterized in that this continuous smooth gear-like outer contour of the radial cross-section of the main body is made up of curve segments with the following characteristics: a group of numbers is 7, and the radius is (β ) around the center point (O), in a circular array within the range of 0 degrees to 360 degrees; the inscribed circle of the outer contour and the adjacent two circles with a radius of (β), the three circles Circumscribed circles, these circumscribed circles form another group of circles with a quantity of 7; they come from these two groups of circles, and they are circumscribed between each other, and each circle forms corresponding 2 tangent points. Take these two tangent points The minor arcs between the points, all these minor arcs are connected end to end to form this continuous smooth gear-like outer contour of the cross section.

3. The catalyst particle according to claim 1, characterized in that the radius (R) of the circumscribed circle of the outer contour line is 3 mm to 5 mm.

4. The catalyst particle according to claim 1, characterized in that the axial height (H) of the particle is 2R to 2.2R.

5. The catalyst particle according to claim 1, characterized in that the radius (r) of the inscribed circle of the outer contour line is 0.8R.

6. The catalyst particle according to claim 2, characterized in that the radius (β) is 0.2R.