CN105363407A - Modified adsorbent and applications of modified adsorbent in ultra-high purity methyl fluoride preparation - Google Patents

Abstract

The present invention discloses an adsorbent modified through an ion exchange method, ball mill method or impregnating method, wherein the adsorbent is selected from an A type molecular sieve, an X type molecular sieve, a Y type molecular sieve, SiO2, Al2O3 or active carbon AC. According to the present invention, the modified adsorbent is suitable for removal of organic impurities from the methyl fluoride crude product so as to obtain the ultra-high purity methyl fluoride product with a purity of more than or equal to 99.999%.

Description

A kind of adsorbent of modification and the application in the single fluoromethane preparation of superelevation thereof

Technical field

The present invention relates to a kind of adsorbent, particularly a kind of modified adsorbent that can be used in the single fluoromethane of preparation superelevation.

Background technology

HFC-41 is a kind of nontoxic, colourless, odorless, flammable liquid gas be stored in steel cylinder, not only can make the raw material producing fluorine Celfume, etchant can also be used as semiconductor dry etching technology, as the plasma etching in integrated circuit, especially HDP (high-density plasma) etching.When being used as the etching of semicon industry, its purity has decisive influence to assembly property and product fine rate, also the disqualification rate of product can be caused to increase sharply even if millionth trace impurity enters operation, therefore the purity requirement of market to electronic gas is more and more higher, its below organic impurity content 10ppm of basic demand, even below 1ppm.

In HFC-41 crude product, following organic impurities may be there is: ethane (C ₂h ₆), ethene (C ₂h ₄), acetylene (C ₂h ₂), propane (C ₃h ₈), propylene (C ₃h ₆), butylene (C ₄h ₈), fluoroform (CHF ₃).Prior art mainly contains following report for the removal of organic impurities in HFC-41 crude product:

Japan Patent JP2013112611A reports containing C ₂h ₄hFC-41 under high pressure through containing the RCOCl (R=C of catalyst _1-3alkyl), can by C ₂h ₄0.001% is reduced to from 0.051%.The method to need HFC-41, first by other liquid, easily bring other impurity into, and disposal ability to be limited, to still have 10ppmC after process ₂h ₄exist, HFC-41 highest purity can only reach 99.99%.

Japan Patent JP2013112611A patent reports 2g containing C ₂h ₆and C (0.008%) ₂h ₄(0.051%) HFC-41 (99.939%) under the high pressure of 60 DEG C with 15gH ₂sO ₄contact 4 hours, can by C ₂h ₄be reduced to 0.002%, but to C ₂h ₆invalid, HFC-41 purity brings up to 99.988%.The method needs a large amount of H ₂sO ₄, treating capacity is little, to C ₂h ₆invalid, and easily introduce moisture, be not suitable for ultra-high purity HFC-41 preparation.

Japan Patent JP2013112612A reports in HFC-41 except CHF ₃method: will containing CHF ₃unstripped gas by DMF, DMF+tert-Buok+ Benzophenone mixed solution, H ₂sO ₄after multiple solution, 0.129%CHF can be removed completely ₃, obtain the HFC-41 of 99.97%.The method process is complicated, needs raw material many, is not suitable for large-scale production, and easily introduces moisture and other impurity, and final HFC-41 purity is not high, and product can not be used for electron trade.

Summary of the invention

The object of the present invention is to provide a kind of adsorbent of modification, can multiple organic impurities contained by deep removal FC-116, and have that adsorption capacity is large, reproducibility good, non-secondary pollution, the advantage such as easy to prepare.

For reaching goal of the invention the technical solution used in the present invention be:

An adsorbent for modification, use ion-exchange, ball-milling method or infusion process to carry out modification to adsorbent, described adsorbent is selected from A type molecular sieve, X-type molecular sieve, Y zeolite, SiO ₂, Al ₂o ₃or active carbon AC carries out modification;

In described ion-exchange, the metal ion-modified liquid concentration of use is 0.01 ~ 5.0mol/L, and described metal ion is selected from Cs ⁺, Ce ³⁺, Cu ⁺, Cu ²⁺, Ag ⁺, K ⁺, Ca ²⁺, La ³⁺, Li ⁺and Co ²⁺in one, more than two or three combination, ion-exchange solid-to-liquid ratio is 1:1 ~ 1:50, and ion-exchange degree is 1.0% ~ 99.9%;

In described ball-milling method, adsorbent and slaine mass ratio are 10:1 ~ 1:5, and sintering temperature 200 ~ 500 DEG C, described slaine is selected from Cs ⁺, Ce ³⁺, Cu ⁺, Cu ²⁺, Ag ⁺, K ⁺, Ca ²⁺, La ³⁺, Li ⁺and Co ²⁺salt in one, more than two or three combination.

In described infusion process, the metal salt solution concentration of use is 0.01 ~ 5.0mol/L, and described slaine is selected from Cs ⁺, Ce ³⁺, Cu ⁺, Cu ²⁺, Ag ⁺, K ⁺, Ca ²⁺, La ³⁺, Li ⁺and Co ²⁺salt in one, more than two or three combination, content of metal is 0.1% ~ 30.0%.

As preferred mode, the above-mentioned adsorbent for modification is preferably from NaA type molecular sieve, NaX type molecular sieve, NaY type molecular sieve, SiO ₂, Al ₂o ₃with the one in active carbon AC, more than two or three combination; The use form of the described adsorbent for modification is 2 ~ 100 orders.

In above-mentioned ion-exchange, as preferred mode, metal ion-modified liquid concentration is preferably 0.01 ~ 2.0mol/L; Described metal ion is preferably from Cs ⁺, Cu ⁺, Ag ⁺and La ³⁺in one, more than two or three combination; Ion-exchange solid-to-liquid ratio is preferably 1:2 ~ 1:10.

In above-mentioned ball-milling method, as preferred mode, described slaine is preferably from Cs ⁺, Cu ⁺, Ag ⁺and La ³⁺salt in one, more than two or three combination, adsorbent and slaine mass ratio are preferably 2:1 ~ 1:2; Sintering temperature is preferably 250 ~ 400 DEG C.

In above-mentioned infusion process, as preferred mode, described slaine is preferably from Cs ⁺, Cu ⁺, Ag ⁺and La ³⁺salt in one, more than two or three combination, the metal salt solution concentration of use is preferably 0.01 ~ 2.0mol/L, and content of metal is 5% ~ 10%.

The present invention also provides a kind of renovation process of adsorbent of modification, regenerates under an inert atmosphere, and regeneration temperature is 110 ~ 300 DEG C, 1 ~ 10 hour recovery time.As preferred mode, regeneration temperature is preferably 200 ~ 350 DEG C,

Modified adsorbent provided by the invention, is suitable for the single fluoromethane of preparation superelevation.When being used to the preparation single fluoromethane of superelevation, suitable modified adsorbent can be selected from modified A type molecular sieve, X-type molecular sieve, Y zeolite, SiO ₂, Al ₂o ₃with the one in active carbon AC, more than two or three combination; Modified adsorbent provided by the invention can remove the impurity in a fluoromethane crude product, and described impurity comprises C ₂h ₆, C ₂h ₄, C ₂h ₂, C ₃h ₈, C ₃h ₆, C ₄h ₈and CHF ₃in one, more than two or three combination.When being used to the preparation single fluoromethane of superelevation, a described fluoromethane crude product enters gas-solid adsorption bed and contacts imurity-removal continuously with the adsorbent of modification after gasification.A described fluoromethane crude product feedstock quality air speed is preferably 0.1 ~ 10.0g/ (g adsorbent h), and more preferably 0.5 ~ 2.0g/ (g adsorbent h).Adsorption temp is preferably-50 ~ 250 DEG C, and more preferably-30 ~ 50 DEG C.Adsorptive pressure is preferably 0.1 ~ 5.0MPa, and more preferably 0.1 ~ 2.0MPa.The purity of the fluoromethane finished product after adsorption treatment can reach more than 6N.

Impurity i Individual uptake of the present invention calculates by formula I

$q_i=\frac{F(C_{i,o}{t}_f-{\∫}_o^{t_f}C\left(t\right)\mathrm{dt})-V_d}{m_{\mathrm{ads}}}$ Formula I

Wherein: q _i: i Individual uptake; y _i: i component mole composition in the gas phase; F: unstripped gas total flow; C (t): i component concentration in the gas phase; t _f: the time (be greater than 1ppm and represent breakdown) when i component breakthrough curve is breakdown; V _d: adsorption plant dead volume.

Modified adsorbent provided by the invention has following distinguishing feature compared to existing technology:

(1) the single fluoromethane product of superelevation of purity >=99.999% can, be obtained;

(2), CFC-13, HFC-23, HFC-32, CFC-115, HFC-125, HFC-143a and HFC-152a organic impurities in a fluoromethane crude product can be removed simultaneously;

(3), adsorption efficiency is high, adsorption capacity is large, reproducibility is good, be applicable to large-scale industry continuous seepage;

(4), nontoxic, environmentally friendly, the non-secondary pollution of adsorbent.

Detailed description of the invention

Below in conjunction with specific embodiment, the present invention is further described, but does not limit the invention to these detailed description of the invention.One skilled in the art would recognize that all alternatives, improvement project and the equivalents that present invention encompasses and may comprise in Claims scope.

Containing C in the HFC-41 crude product that the present invention uses ₂h ₆, C ₂h ₄, C ₂h ₂, C ₃h ₈, C ₃h ₆, C ₄h ₈, CHF ₃etc. main organic impurities, adsorbent provided by the invention can remove these organic impurities effectively.

Each organic impurity content in table 1, HFC-41 crude product

Impurity composition	C 2H 6	C 2H 4	C 2H 2	C 3H 8	C 3H 6	C 4H 8	CHF 3
								Content/ppm	154	326	237	58	486	1372	276

Embodiment 1

Take 10gNaX molecular screen primary powder, mix by 1:3 solid-to-liquid ratio with 0.1mol/L concentration LiCl solution, at 80 DEG C, stir 4h.Filtering molecular sieves, and the fresh LiCl solution again adding 0.1mol/L concentration by 1:3 solid-to-liquid ratio carries out ion-exchange.This process repeats 4 times, guarantees Na ⁺completely by Li ⁺exchange.Filtering solids, is washed with distilled water to without Cl ^-1.110 DEG C of dry 8h of air dry oven.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 2

Take 10gNaY molecular screen primary powder, mix by 1:3 solid-to-liquid ratio with 0.1mol/L concentration LiCl solution, at 80 DEG C, stir 4h.Filtering molecular sieves, and the fresh LiCl solution again adding 0.1mol/L concentration by 1:3 solid-to-liquid ratio carries out ion-exchange.This process repeats 4 times, guarantees Na ⁺completely by Li ⁺exchange.Filtering solids, is washed with distilled water to without Cl ^-1.110 DEG C of dry 8h of air dry oven.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 3

Take 10gSiO ₂with 20gLiCl solid, be placed in ball mill and fully grind 60min, then take out, roasting 8h at 350 DEG C, to promote that LiCl is at SiO ₂dispersion on surface.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 4

Get active carbon AC10g, add 0.1mol/L concentration LiCl solution 5.5ml, dipping 24h, then dried overnight in 110 DEG C of air dry ovens.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 5

Get active carbon AC10g, add 0.1mol/L concentration above-mentioned CsCl solution 5.5ml, dipping 24h, then dried overnight in 110 DEG C of air dry ovens.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 6

Get active carbon AC10g, add 0.1mol/L concentration C uCl solution 5.5ml, dipping 24h, then dried overnight in 110 DEG C of air dry ovens.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 7

Get active carbon AC10g, add 0.1mol/L concentration La (NO ₃) ₃solution 5.5ml, dipping 24h, then dried overnight in 110 DEG C of air dry ovens.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 8

Get active carbon AC10g, add 0.1mol/L concentration AgNO ₃solution 5.5ml, dipping 24h, then dried overnight in 110 DEG C of air dry ovens.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 9

Get active carbon AC10g, add 0.1mol/L concentration C e (NO ₃) ₃solution 5.5ml, dipping 24h, then dried overnight in 110 DEG C of air dry ovens.Get a certain amount of sample in gas-solid phase adsorbent equipment, at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 10

Adsorbent after Example 5 adsorbs carries out regeneration and the 2nd absorption.Regeneration condition is with first time activation: at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 11

Adsorbent after Example 10 adsorbs carries out regeneration and the 3rd absorption.Regeneration condition is with first time activation: at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 12

Adsorbent after Example 11 adsorbs carries out regeneration and the 4th absorption.Regeneration condition is with first time activation: at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Embodiment 13

Adsorbent after Example 12 adsorbs carries out regeneration and the 5th absorption.Regeneration condition is with first time activation: at 350 DEG C, N ₂atmosphere situ activation 2h, after cooling, logical unstripped gas HFC-41 carries out adsorption-edulcoration.

Each embodiment experimental data is in table 2 and table 3.

Table 2 each embodiment adsorbent capacity

Table 3, each embodiment impurity absorption degree of depth

From above embodiment data, the organic impurities in a fluoromethane crude product is removed to below 10ppb by the modified adsorbent of the present invention, can obtain high-purity FC-116 product of more than purity 6N.And adsorbent capacity is large, after repeatedly regenerating, still can keep substantially identical adsorption capacity.

Claims (10)

1. an adsorbent for modification, it is characterized in that using ion-exchange, ball-milling method or infusion process to carry out modification to adsorbent, described adsorbent is selected from A type molecular sieve, X-type molecular sieve, Y zeolite, SiO ₂, Al ₂o ₃or active carbon AC;

In described ion-exchange, the metal ion-modified liquid concentration of use is 0.01 ~ 5.0mol/L, and described metal ion is selected from Cs ⁺, Ce ³⁺, Cu ⁺, Cu ²⁺, Ag ⁺, K ⁺, Ca ²⁺, La ³⁺, Li ⁺and Co ²⁺in one, more than two or three combination, ion-exchange solid-to-liquid ratio is 1:1 ~ 1:50, and ion-exchange degree is 1.0% ~ 99.9%;

In described ball-milling method, adsorbent and slaine mass ratio are 10:1 ~ 1:5, and sintering temperature 200 ~ 500 DEG C, described slaine is selected from Cs ⁺, Ce ³⁺, Cu ⁺, Cu ²⁺, Ag ⁺, K ⁺, Ca ²⁺, La ³⁺, Li ⁺and Co ²⁺salt in one, more than two or three combination;

In described infusion process, the metal salt solution concentration of use is 0.01 ~ 5.0mol/L, and described slaine is selected from Cs ⁺, Ce ³⁺, Cu ⁺, Cu ²⁺, Ag ⁺, K ⁺, Ca ²⁺, La ³⁺, Li ⁺and Co ²⁺salt in one, more than two or three combination, content of metal is 0.1% ~ 30.0%.

2., according to the adsorbent of modification according to claim 1, it is characterized in that the adsorbent of described modification is used to the single fluoromethane of preparation superelevation, the described adsorbent for modification is selected from NaA type molecular sieve, NaX type molecular sieve, NaY type molecular sieve, SiO ₂, Al ₂o ₃with the one in active carbon AC, more than two or three combination, the use form of described adsorbent is 2 ~ 100 orders.

3. according to the adsorbent of modification according to claim 1, it is characterized in that in described ion-exchange, metal ion-modified liquid concentration is 0.01 ~ 2.0mol/L, and described metal ion is selected from Cs ⁺, Cu ⁺, Ag ⁺and La ³⁺in one, more than two or three combination, ion-exchange solid-to-liquid ratio is 1:2 ~ 1:10.

4., according to the adsorbent of modification according to claim 1, it is characterized in that, in described ball-milling method, described slaine is selected from Cs ⁺, Cu ⁺, Ag ⁺and La ³⁺salt in one, more than two or three combination, adsorbent and slaine mass ratio are 2:1 ~ 1:2, sintering temperature 250 ~ 400 DEG C.

5., according to the adsorbent of modification according to claim 1, it is characterized in that, in described infusion process, described slaine is selected from Cs ⁺, Cu ⁺, Ag ⁺and La ³⁺salt in one, more than two or three combination, the metal salt solution concentration of use is 0.01 ~ 2.0mol/L, and content of metal is 5% ~ 10%.

6., according to the adsorbent of modification according to claim 1, it is characterized in that the adsorbent of described modification is for removing the impurity in a fluoromethane crude product, described impurity comprises C ₂h ₆, C ₂h ₄, C ₂h ₂, C ₃h ₈, C ₃h ₆, C ₄h ₈and CHF ₃in one, more than two or three combination.

7. according to the adsorbent of modification according to claim 6, it is characterized in that a described fluoromethane crude product enters gas-solid adsorption bed and contacts imurity-removal continuously with the adsorbent of modification after gasification, a described fluoromethane crude product feedstock quality air speed is 0.1 ~ 10.0g/ (g adsorbent h), adsorption temp is-50 ~ 150 DEG C, and adsorptive pressure is 0.1 ~ 5.0MPa.

8. according to the adsorbent of modification according to claim 7, it is characterized in that a described fluoromethane crude product feedstock quality air speed is 0.5 ~ 2.0g/ (g adsorbent h), adsorption temp is-30 ~ 50 DEG C, adsorptive pressure is 0.1 ~ 2.0MPa, and the purity of the fluoromethane finished product after adsorption treatment is more than 6N.

9. according to the adsorbent of the modification one of claim 1 to 8 Suo Shu, it is characterized in that the adsorbent of described modification can regenerate under an inert atmosphere, regeneration temperature is 110 ~ 400 DEG C, 1 ~ 10 hour recovery time.

10., according to the adsorbent of modification according to claim 9, it is characterized in that described regeneration temperature is, 200 ~ 3500 DEG C, 2 ~ 5 hours recovery times.