CN1646428A - Method for purifying solutions containing cyanamide - Google Patents

Method for purifying solutions containing cyanamide Download PDF

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Publication number
CN1646428A
CN1646428A CN 03808632 CN03808632A CN1646428A CN 1646428 A CN1646428 A CN 1646428A CN 03808632 CN03808632 CN 03808632 CN 03808632 A CN03808632 A CN 03808632A CN 1646428 A CN1646428 A CN 1646428A
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China
Prior art keywords
cyanamide
film
solution
membrane
desired method
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Granted
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CN 03808632
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Chinese (zh)
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CN100333824C (en
Inventor
T·古特纳
J·法泽纳赫特
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Evonik Operations GmbH
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Degussa GmbH
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Publication of CN1646428A publication Critical patent/CN1646428A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/02—Reverse osmosis; Hyperfiltration ; Nanofiltration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
    • B01D61/14—Ultrafiltration; Microfiltration
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
    • C01C3/00—Cyanogen; Compounds thereof
    • C01C3/16—Cyanamide; Salts thereof

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Chemistry (AREA)
  • Nanotechnology (AREA)
  • Inorganic Chemistry (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)

Abstract

The invention relates to a method for purifying solutions containing cyanamide, according to which the parent solution is subjected to a membrane filtration at temperatures of between -20 and +80 DEG C, whereby the separation membrane has an MWCO value of between 80 Da and 60 kDa and the parent solution is subjected to a pressure of between 2.5 and 60 bar. In said method, which preferably operates according to the feed-and-bleed principle and whereby the solution retained by the membrane is subjected to a circulatory flow in front of the membrane, parent solutions having a cyanamide content of between 5 and 60 wt. % are used. This permits over 80 % of compounds containing in particular calcium, iron, nickel and silicon to be eliminated from the solutions used.

Description

Be used for the method that purifying comprises the solution of cyanamide
The present invention relates to the method that a kind of purifying contains the solution of cyanamide.
Cyanamide is industrial to be made by calcium cyanamide, and the latter is again from lime, carbide of calcium and nitrogen.
Will there be metal wherein in the raw material calcium cyanamide, and as iron, nickel and calcium are introduced the technology that is used to prepare cyanamide.The amount of contaminant metals and concentration depend primarily on the starting raw material coke used when preparing calcium cyanamide and the quality of lime.The used fuel gas and the kind and the composition of oil fuel when the impurity in the lime mainly comes auto-combustion lime.During carbide of calcium, metallic impurity are introduced into product by coke and by burning used blast furnace electrode in preparation, and wherein impurity comes (steel) outsourcing thing of self-electrode in the case.
Although thick relatively impurity such as graphite, Fe 2O 3, CaCO 3, SiO 2Discharge by revolving filter when the preparation cyanamide solution with ferrosilicon, contain just like iron, the above-mentioned segmentation impurity of nickel and calcium is stayed the neutralization of product solution and is caused and for example be the typical variable color of ion institute, the mass defect of turbidity or precipitated form.
In order to overcome this problem, ion-exchanger (Ullmanns industrial chemistry encyclopaedia, the 6th edition, 2001) is used in suggestion, but this does not bring required success.In this article, the also known cationite that utilizes is attempted purifying cyanamide solution (Zh.Prikl.Khim (Leningrad) 1966, V.39, No.11, number of pages 2581/2)
But also attempt using the Weak-acid cation exchanger to remove the iron and the calcium ion of phosphoric acid salt-stabilization cyanamide solution.Although calcium ion can be removed to small part by this method, iron ion is stayed in the cyanamide solution (the undocumented experiment of being undertaken by the applicant).
Many membrane filtering methods are learnt from prior art.These comprise separation known principle own, and wherein material is according to its particle, molecule or ion size and keep.When membrane filtration, carry out the difference of two kinds of modification in principle:
In pore model, if particle diameter greater than bore dia, the particle in the liquid is stayed on the hole of film.Liquid and can pass through (infiltration) only than small-particle.Filter cake or the liquid stream (retentate) with solids content of increase stay.
Be to use the ultrafiltration of micro-filtration and about 0.003 to the 0.1 μ m of use hole width of about 0.05 to the 2.0 μ m of hole width according to the membrane separation process of this operate.
Motivating force is a pressure reduction between charging side and the permeate side at this.
In the solution diffusion model, film is as fine and close separating layer.Reinforced logistics and dissolving composition wherein are dissolved in the film neutralization and diffuse through.The material that stays only is slightly soluble in the used film and/or has low rate of diffusion, and obviously more desired substance passes through from film in the identical time like this.
The type of this membrane sepn is called reverse osmosis or ultrafiltration.
Separation limit in this model provides with molecular dimension, and wherein the molecular weight of the stdn polysaccharide of membrane sepn limit is determined in weight shutoff value (MWCO) expression according to its size of standardized method.In reverse osmosis, stay molecule usually with molecular weight 30 to 300g/mol.The film of Shi Yonging also partly is characterized by its value that keeps NaCl in water for this reason.
Motivating force in this model is the pressure reduction between charging side and the permeate side.
Same known two kinds of given model mix forms are nanofiltration techniques:
The feature that these two models were operated and combined to the borderline region of nanofiltration between ultrafiltration and reverse osmosis.
Separate limit normally diameter 0.8 to 600nm or molecular dimension 80 to 15000g/mol.
When filtering, solvent directly takes out from suspension or solution on film, and the composition that stays is concentrated.This effect is called concentration polarization; On film, form tectum.
Therefore, attempt in reinforced logistics, producing very strong turbulent flow on the film in order to make this tectum extremely thin and offset concentration polarization.
For this reason, reinforced logistics is parallel, and the logistics that is rich in pollutent is like this left membrane module at the end of film through film, and this is called retentate.This principle is called " crossing current " principle.
Because obtain big relatively retentate stream in this crossing current method, membrane module is as " reinforced-and-ooze out system " operation.At this, retentate is recirculated to before the membrane module.The little logistics that is called enriched material flows out from this loop by pressure regulator valve.High-pressure pump must only be transmitted the volume logistics that produces from the summation of penetrant and enriched material.Recirculating pump is carried a large amount of volume logistics of clashing on membrane module.This must can only overcome the pressure drop that charging side produced of this fluid by assembly again.
But this technology shortcoming is that processing condition are difficult to match with different molecules or ion size, and colloid composition stops up fenestra especially easily.
Therefore an object of the present invention is to provide the method that a kind of purifying contains the solution of cyanamide, from solution, remove interferential ionic impurity iron like this, the feasible disadvantageous effect of eliminating product quality of nickel and calcium.
This purpose realizes by the inventive method, and wherein starting soln carries out membrane filtration in temperature-20 under to+80 ℃, and wherein MWCO value and the starting soln of separatory membrane with 80Da to 60kDa is under the pressure of 2.5 to 60 crust.
Find shockingly that if use this method, as the iron of the major impurity in the cyanamide solution, nickel and calcium can be removed to and surpass 90%, and other interfering substance such as SiO2 are removed to usually and surpass 80%.This is more astonishing completely because silicate known be to be difficult to relatively usually utilize membrane filtration and removed strong rubber body compound because formed silica gel stops up fenestra and therefore hinders or even prevent that other ionic from removing.Therefore, not this success of expectability basically.
Present method advantageously is applied to have the starting soln of cyanamide content 5 to 60% weight.Moisture or pure starting soln is especially suitable.
Used film can use by various forms: as planar film (be similar on the structure and have dull and stereotyped pressure filter), as hollow-fiber module (light wall pipe bundle), as tubular assembly (thick pipe) or as winding assembly (rolling).Because the structure and relative low manufacturing cost of its compacting adopt winding assembly usually.
Reinforced solution flows into membrane module at its end face, and wherein the penetrant tunicle separates.Residuum leaves assembly in the other end as retentate.
Have been found that in the methods of the invention the MWCO value of separatory membrane is 150 to 1000 dalton advantageously, especially preferred 200 to 500 dalton.
Comprising polymeric amide also is preferred according to the present invention as the separatory membrane of separating layer.
In most of occasions, film is not only to form (symmetric film) by individual layer, but has asymmetrical structure.At this, extremely thin active separating layer is applied on the thicker carrier layer.Carrier layer normally gross porosity with to separating not contribution.It just guarantees pressure stability.Can advise existing another layer as the joint cement between separating layer and the carrier layer.
Under situation of the present invention, the active separating layer of used film comprises polymeric amide, and carrier can be a polyethylene for example.Therefore this film is composite membrane.
In the important pressure range to the present invention that starting soln will stand, pressure 10 to 40 crust are found to be useful.
In normal running, above-mentioned tectum forms on film.Can be removed by cleaning at this sedimentary most of material, but small part stays and can be slowly but damage the performance that flows through of film constantly.
Make settled solution such as water just be enough to decoat usually simply through this film.But also but Xiang Shuizhong adds cleaning compositions, and cleaning soln becomes acid or alkaline like this.Be used for pH buffered salt, enzyme or tensio-active agent can be present in the added cleaning compositions in addition.If when cleaning under higher temperature, the solubleness that is positioned at the impurity on the film is higher.Therefore advantageously use and have the highest 40 ℃ cleaning soln of temperature.In general, film in the permeate side cleaning, is not rinsed from membrane module by penetrant because enter the material of permeate side in operating process.
Therefore the solution that has been found that this film and kept advantageously circulates in the front of film, and this provides as preferred variation of the present invention equally.
In this article, have been found that the inventive method particularly advantageously according to reinforced-and-oozing out principle carries out.
In the favourable possible modification of the inventive method, notice that an advantageous variant is wherein calcareous, iron content-and/or compound, especially silica nickel or siliceous, or its mixture is isolated from starting soln.
Following examples illustration purifying contains these advantages of method of the solution of cyanamide according to the present invention.
Embodiment
Following experiment uses two winding assemblies with 4 * 40 inches of sizes to carry out, and wherein each assembly has membrane area 4.5m 2
Reinforced solution transfers to receiving vessel from the circulation loop of the storage vessel that is used for cyanamide solution by pre-filtering continuously.Amafilter HPM97-01-1SS) and candle filter (6 candle bodies with hole width 0.5 μ m: Amafilter Part# T8619508246 the bag type filter (immersed filter with nominal pore width 1 μ m: is used in pre-filtering; WS 0.5-20U-X9 246) carries out.
This device uses recirculation under high pressure to carry out, and wherein penetrant and enriched material continuously flow into corresponding hold-up vessel.The quadruple double pipe heat exchanger of water coolant operation is present in the retentate loop.
Select following operating parameters:
Working pressure is set at 20,30 and 40 crust three pressure stages.
Selecting to concentrate ratio (penetrant and reinforced ratio) is 50,75,82 and 90%, corresponds respectively to enriched material: penetrant ratio 100%, 33%, 22% and 11%.
The characteristic parameter of measuring is the pressure on reinforced and retentate side, the retentate temperature, and the pressure drop on the bag type filter, the volumetric flow rate of penetrant and enriched material and the material retained of wanting are calcium, iron, nickel and SiO 2In reinforced (in each case after pre-filtering), in penetrant and the concentration in enriched material.
The result:
As the flux performance of film, 3.3ltr./(hm 2Crust) permeate flux uses process water to measure down at 20 ℃ as feeding in raw material.
In the operation of the cyanamide solution that uses 50% concentration, about 0.85ltr./(hm 2Crust) film that permeate flux is used new cleaning obtains under about 17 ℃ of pressure 20 to 40 crust and temperature.This value is reduced to about 0.25 liter/(hm at a broom closet every interior 2Crust).
Purification performance:
Table 1 has provided the substance C a that is detected, Fe, SiO 2Analytical value and corresponding retention value with nickel.The various retention values of the pollutent of being considered are determined by analytical value.Especially at SiO 2Situation under, retention value fluctuation is bigger, because SiO 2Can exist with various forms owing to its colloidal property.
The experiment number Pressure [bar] Sample time [h] Ca[mg/l] Fe[mg/l] SiO 2[mg/l] Ni[mg/l]
Reinforced Penetrant Retention value [%] Reinforced Penetrant Retention value [%] Reinforced Penetrant Retention value [%] Reinforced Penetrant Retention value [%]
?1 ?20 ?30 ?40 ?2 ?2 ?2 ?332 ?350 ?386 ?35 ?34 ?39 ??89 ??90 ??90 ??140 ??152 ??166 ??8.3 ??8.5 ??10.0 ??94 ??94 ??94 ??113 ??157 ??146 ??20 ??21 ??23 ?82 ?87 ?84 ?- ?- ?- ?- ?- ?- ??- ??- ??-
?2 ?20 ?20 ?20 ?20 ?20 ?20 ?20 ?20 ?20 ?20 ?20 ?20 ?12 ?24 ?36 ?48 ?60 ?72 ?96 ?120 ?114 ?192 ?216 ?240 ?104 ?99 ?107 ?95 ?106 ?109 ?108 ?118 ?115 ?115 ?125 ?124 ??- ??15 ??15 ??18 ??21 ??17 ??14 ??15 ??12 ??13 ??12 ??12 ??- ??85 ??86 ??81 ??80 ??84 ??87 ??87 ??90 ??89 ??90 ??90 ??29 ??27 ??27 ??26 ??28 ??29 ??27 ??29 ??28 ??31 ??35 ??34 ??- ??2.1 ??2.0 ??2.0 ??2.1 ??2.1 ??1.7 ??1.6 ??1.4 ??1.2 ??1.0 ??1.2 ??- ??92 ??93 ??92 ??93 ??93 ??94 ??94 ??95 ??96 ??97 ??96 ??55 ??41 ??51 ??44 ??53 ??57 ??54 ??54 ??64 ??71 ??70 ??63 ??- ??5.0 ??5.0 ??7.3 ??6.9 ??11.0 ??9.9 ??10.0 ??10.0 ??11.0 ??9.7 ??12.0 ?- ?88 ?90 ?83 ?87 ?81 ?82 ?81 ?84 ?85 ?86 ?81 ?19 ?18 ?19 ?18 ?19 ?19 ?17 ?20 ?18 ?22 ?24 ?23 ?- ?2.4 ?2.3 ?2.2 ?2.3 ?2.3 ?2.1 ?1.9 ?1.4 ?1.5 ?1.4 ?1.5 ??- ??87 ??88 ??88 ??88 ??88 ??88 ??91 ??92 ??93 ??94 ??93

Claims (9)

1. a purifying contains the method for the solution of cyanamide, is characterised in that starting soln carries out membrane filtration in temperature-20 under to+80 ℃, and MWCO value and starting soln that wherein used separatory membrane has 80Da to 60kDa are under the pressure of 2.5 to 60 crust.
2. the desired method of claim 1 is characterised in that used starting soln has cyanamide content 5 to 60% weight.
3. claim 1 or 2 desired methods are characterised in that and use moisture or pure starting soln.
4. any one desired method of claim 1 to 3, the MWCO value that is characterised in that separatory membrane are 150 to 1000Da, and especially preferred 200 to 500Da.
5. any one desired method of claim 1 to 4 is characterised in that separatory membrane comprises polymeric amide as separating layer.
6. any one desired method of claim 1 to 5 is characterised in that starting soln is under the pressure of 10 to 40 crust.
7. any one desired method of claim 1 to 6 is characterised in that the solution that this film is left circulates in the front of film.
8. any one desired method of claim 1 to 7, be characterised in that its according to reinforced-and-oozing out principle carries out.
9. any one desired method of claim 1 to 8 is characterised in that calcareous, iron content and/or nickel or siliceous compound, silica especially, or its mixture is isolated from starting soln.
CNB038086328A 2002-04-19 2003-04-16 Method for purifying solutions containing cyanamide Expired - Fee Related CN100333824C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10217530.6 2002-04-19
DE2002117530 DE10217530B4 (en) 2002-04-19 2002-04-19 Process for the purification of cyanamide-containing solutions

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CN1646428A true CN1646428A (en) 2005-07-27
CN100333824C CN100333824C (en) 2007-08-29

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JP (1) JP2005523227A (en)
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DE (1) DE10217530B4 (en)
WO (1) WO2003089372A2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110921682A (en) * 2019-12-19 2020-03-27 山东益丰生化环保股份有限公司 Purification method of cyanamide solution

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110694479A (en) * 2019-10-31 2020-01-17 山东益丰生化环保股份有限公司 Purification method of cyanamide solution

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3370922A (en) * 1965-03-23 1968-02-27 Hoffmann La Roche Purification of cyanamide
US3300281A (en) * 1965-08-06 1967-01-24 American Cyanamid Co Method for manufacture of cyanamide
US4617127A (en) * 1985-05-20 1986-10-14 Allied Corporation Production of low alcoholic content beverages
US5843318A (en) * 1997-04-10 1998-12-01 Sachem, Inc. Methods of purifying hydroxlamine solutions and separating hydroxylamine from hydroxlamine salts

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110921682A (en) * 2019-12-19 2020-03-27 山东益丰生化环保股份有限公司 Purification method of cyanamide solution

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DE10217530A1 (en) 2003-11-13
EP1497227A2 (en) 2005-01-19
WO2003089372A3 (en) 2004-02-05
CN100333824C (en) 2007-08-29
WO2003089372A2 (en) 2003-10-30
JP2005523227A (en) 2005-08-04
DE10217530B4 (en) 2006-04-20

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