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A modified platinum-based catalytic network for preparing nitric acid by ammonia oxidation and its preparation method

A platinum-based catalytic net, ammonia oxidation technology, applied in chemical instruments and methods, nitrogen oxides/oxyacids, nitric acid, etc., can solve the problems of decreased activity, increased platinum consumption, and difficulty in secondary utilization, etc. Catalyst activity, effect of increasing rigidity strength and durability

Active Publication Date: 2020-10-02
CNOOC TAIYUAN PRECIOUS METALS
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

During the use of platinum-based alloy catalysts, under the continuous impact of high-temperature and high-pressure airflow, the platinum on the surface will be oxidized to form platinum oxide, which will be continuously peeled off and taken away with the airflow, which will cause the so-called "platinum consumption". After 6 months of use, the platinum consumption increases sharply and the activity decreases significantly, so the platinum-based alloy catalyst must be replaced after 6 months of use under normal processes, and it is difficult to reuse

Method used

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  • A modified platinum-based catalytic network for preparing nitric acid by ammonia oxidation and its preparation method
  • A modified platinum-based catalytic network for preparing nitric acid by ammonia oxidation and its preparation method

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Effect test

Embodiment 1

[0046] According to the high-palladium catalytic network scheme for ammonia oxidation to nitric acid, the filling mode and structure of the catalytic network in the main reaction zone, secondary reaction zone and supplementary reaction zone were designed. Then smelt platinum-palladium alloy with a noble metal purity of 99.95% (the content of palladium accounts for 30%), and make a semi-finished high-palladium catalytic net through rolling, wire drawing and weaving. The material parameters meet: the wire diameter is 0.06-0.09mm, the tensile strength is ≥343MPa, and the elongation is ≥8%. The semi-finished product is embossed by a laser-engraved stainless steel yin-yang steel rod. The pattern is designed as a quadrilateral, pentagonal or hexagonal shape formed by the spiral structure of the Fibonacci sequence lattice, with a depth of 1.0mm and a slope of 120°. The line width is 2.5 mm. After the surface is patterned, it is wound up on a plastic roll for hydrogen activation, cool...

Embodiment 2

[0048] According to the high-palladium catalytic network scheme for ammonia oxidation to nitric acid, the filling mode and structure of the catalytic network in the main reaction zone, secondary reaction zone and supplementary reaction zone were designed. Then smelt platinum-palladium alloy with a noble metal purity of 99.95% (the content of palladium accounts for 30%), and make a semi-finished high-palladium catalytic net through rolling, wire drawing and weaving. The material parameters meet: the wire diameter is 0.06-0.09mm, the tensile strength is ≥343MPa, and the elongation is ≥8%. The surface of the semi-finished product is patterned by laser-engraved stainless steel yin and yang steel rod embossing equipment. The pattern design is a quadrilateral, pentagonal or hexagonal shape formed by the spiral structure of the Fibonacci sequence lattice, with a depth of 2.0mm and a slope of 120°. The gradient shading plus line width is 2.0mm. After the surface is patterned, it is wo...

Embodiment 3

[0050] According to the high-palladium catalytic network scheme for ammonia oxidation to nitric acid, the filling mode and structure of the catalytic network in the main reaction zone, secondary reaction zone and supplementary reaction zone are designed. Then smelt platinum-palladium alloy with a noble metal purity of 99.95% (the content of palladium accounts for 30%), and make a semi-finished high-palladium catalytic net through rolling, wire drawing and weaving. The material parameters meet: the wire diameter is 0.06-0.09mm, the tensile strength is ≥343MPa, and the elongation is ≥8%. The semi-finished product is embossed by a laser-engraved stainless steel yin-yang steel rod. The pattern is designed as a quadrilateral, pentagonal or hexagonal shape formed by the spiral structure of the Fibonacci sequence lattice, with a depth of 3.0mm and a slope of 135°. The line width is 2.5 mm. After the surface is patterned, it is wound up on a plastic roll for hydrogen activation, cooli...

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Abstract

The invention discloses a modified platinum-based catalyst gauze for preparation of nitric acid through ammoxidation and a preparation method thereof. The surface of the modified platinum-based catalyst gauze for preparation of the nitric acid through the ammoxidation is reconstructed based on a mathematic principle 'Fibonacci Sequence', a spiral dot matrix is drawn from the center of a platinum-based catalyst to outside, and clockwise and anticlockwise spiral numbers accord with the Fibonacci Sequence F(n)= F(n-1)+ F(n-2). According to the modified platinum-based catalyst gauze disclosed by the invention, surface pattern construction is further carried out on the basis of a filling mode and structure of the modified platinum-based catalyst gauze, a microstructure is constructed again, theactivity of the catalyst is increased, and the rigidity strength and the durability of the modified platinum-based catalyst gauze are increased; the effective using time of the modified platinum-based catalyst gauze is prolonged, and the using cost of the modified platinum-based catalyst gauze is reduced. According to the preparation method disclosed by the invention, the rigidity strength is ensured to be increased based on that the catalytic activity of the platinum-based catalyst gauze is increased, the service life of the catalyst is effectively prolonged, and the production cost is reduced.

Description

technical field [0001] The invention relates to a platinum-based catalyst for nitric acid production, in particular to a modified platinum-based catalytic net for nitric acid production by ammonia oxidation and a manufacturing method thereof. Background technique [0002] Nitric acid production generally adopts the Oswald process, that is, ammonia and oxygen react to form nitric oxide at a temperature of 800-950°C and a pressure of 0.1-1.1MPa, using a platinum-based alloy catalyst. At present, the platinum-based alloy catalysts used in industry include flat woven nets, binary weft knitted nets, binary warp knitted nets, and high palladium catalytic nets. Due to the excellent specific surface area and scientific precious metal filling method, the high palladium catalytic mesh greatly reduces the purchase cost of the catalytic mesh and the cost of platinum consumption, and has been widely used. During the use of platinum-based alloy catalysts, under the continuous impact of h...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J19/24C01B21/38
CPCB01J19/2495B01J2219/30265B01J2219/30475C01B21/38
Inventor 韩勇强刘晓红刘欣赵麦变乔建国
Owner CNOOC TAIYUAN PRECIOUS METALS