CN1229806A - Refining tech. of polyether polyol - Google Patents

Abstract

A process for refining polyether polyol (PPG) by neutralization and adsorption includes neutralization while controlling the water content in system to less than 1%, adding the inorganic salt hydrate as crystal seeds, pheol derivative as precipitant and adsorbent, dewatering, and cyclic filter to remove salts. Its advantages are that the dewatering time is reduced from 260 min to 180 min and the filtering time from 170 to 120 min, resulting in higher efficiency increased by 30%.

Description

A kind of polyether glycol process for refining

The present invention relates to a kind of polyether glycol (PPG) refining technique, it belongs to a kind of neutralization-refining with adsorbents processing method.

Polyether glycol production generally has two procedures: the one, and the polyreaction operation, promptly in the presence of basic catalyst (alkali metal hydroxide, alkali metal alkoxide or alkali metal weak), in reactor, carry out the crude polyoxyalkylene polyol that polyreaction obtains containing minor amount of water and an alkali metal salt with compound that contains reactive hydrogen (as water, polyvalent alcohol, sugar, amine etc.) and olefin oxide (as propylene oxide, oxyethane etc.), this crude polyoxyalkylene polyol contains basic catalyst between 1000-10000ppm, must be through refinement treatment; The 2nd, refining step is about to alkaline matter in the polyether glycol and carries out neutralizing treatment and remove wherein water and salts substances, makes its alkali content less than 5ppm.Therefore the refining step of polyether glycol just becomes the important component part that polyethers is produced.At present the method for refining polyether glycol roughly is divided into following five kinds in the world: a. cation exchange resin processes, and among the b. and partition method, c. adsorption method of separation, d. neutralization-absorption method, e. extraction-absorption method.Wherein using more is neutralization-absorption method, (consulting US4129718), and the processing step of this method is, at first adds a certain amount of water to thick PPG system, makes its moisture 4-5%, uses the basic catalyst among the mineral acid neutralized crude PPG again; After neutralization, still remaining little amount of catalyst ion and coloring matter among the PPG are so also must carry out adsorption treatment with sorbent material; Dry under the 90-120 degree at last, filtration obtain refining PPG product.This method, good product quality, but the refining time of dehydration is long, and production efficiency is low.

The purpose of this invention is to provide a kind of high efficiency neutralization-adsorption refining method, this process for purification, dewatering time is short, and refining effect is good.

Process for refining process provided by the invention is, crude polyoxyalkylene polyol (PPG) is put into and still, be warming up to the 80-90 degree, start stirring, the adding neutralizing agent also reacted 10-30 minute, make pH value of solution=4.8-6, in N-process, the Controlling System water content is below 1.0%, and the adding inorganic salt hydrate is done crystal seed, phenol derivatives is done precipitation agent, adds sorbent material again; The hydrate add-on is the 0.03-1.0% of PPG, and precipitation agent is the 0.1-0.5% of PPG, and sorbent material is the 0.05-0.2% of PPG; Be warming up to the 95-120 degree, under agitation reacted 30-50 minute, carry out drying and dehydrating again and handle-dehydration by evaporation and feed nitrogen and dry up 150-180 minute under negative pressure; Carried out at last circulating filtration 0.5-1.0 hour, and removed wherein each kind of salt, when system contains catalyst metal ion (K ⁺) during less than 5ppm, obtain refining polyether glycol.

Neutralizing agent provided by the invention is that ionization constant is greater than 10 ^-3Strong acid or middle strong acid, as H ₂SO ₄, HCl, HNO ₃, H ₃PO ₄, HClO ₃, H ₂PO ₂Deng.Crystal seed hydrate provided by the invention comprises MgSO ₄H ₂O, MgSO ₄7H ₂O, NaH ₂PO ₃H ₂O, NaH ₂PO ₄12H ₂O, Na ₂SO ₄10H ₂O, KAl (SO ₄) ₂12H ₂O, ZnSO ₄7H ₂O etc. contain the hydrate of a crystal water at least.Precipitation agent phenol derivatives provided by the invention, comprise 2,6 di tert butyl 4 methyl phenol (BHT), 1,3,5-trimethylammonium-2,4,6-three (3 ＇, 5 ＇-di-t-butyl)-4-hydroxybenzyl benzene, 2-(2-hydroxyl-3-tertiary butyl benzyl) methyl-phenoxides etc., add-on is 0.1-0.5%, is preferably 0.2-0.5%.Sorbent material provided by the invention comprises synthetic magnesium silicate, synthetic aluminium silicate, MgCO ₃, CaCO ₃, active diatom soil etc., consumption is 0.05-2.0%, is preferably 0.05-0.2%.

Use process for purification provided by the invention, the time of dehydrating can shorten to 180 minutes by 260 minutes, and filtration time can foreshorten to 120 minutes by 170 minutes, and efficient has improved about 30%.

Embodiment:

Embodiment 1. adds 55.5g glycerine in three liters of stainless steel stills, 4.25gKOH, dewater 80 ℃ of decompressions, then with 180g oxyethane at 110 ℃, 4Kg pressure is reaction down, is reacting with under the condition with the 1600g propylene oxide again, obtain the thick polyethers of 1800g, thick polyethers adds water 5g, is neutralized to Ph=4.8 with 50% phosphoric acid, adds NaH successively ₂PO ₄H ₂O 1.8g, BHT 3.6g, MgSiO ₃1.8g, remove water filtration and obtain polyether product, be analyzed as follows: water-content 0.032%, pH=5.3, V _OH=61mgKOH/g.

Embodiment 2. gets poly(propylene oxide) glyceryl alcohol 1000 grams of molecular weight 3000, adds in the 2000ml four-hole bottle, is warming up to 80 ℃, and adding concentration is the H of 50% (wt) ₃PO ₄14g stirred 10 minutes, and pH=5.0 adds MgSO successively ₄7H ₂O 1g, BHT 2g, MgSiO ₃Lg then at 95 ℃, dewatered under the 10mmHg pressure 3 hours, was the bulk precipitation in the back mixture that dewaters, and no suspended substance in the solution filters with B, and analytical results is as follows: water-content 0.024%, potassium (K ⁺) 1.9ppm, pH=5.5, appearance transparent.

Embodiment 3. is at 6M ³In and add the poly(propylene oxide) glyceryl alcohol of 3000Kg molecular weight 3000 in the still, be warming up to 90 ℃, add water, stirring, add the phosphoric acid of 18.5Kg85% again, stir; Add 3KgNaH successively ₂PO ₄H ₂O, 4.5Kg BHT stirred 40 minutes, when pH=4.8-5.2 is surveyed in sampling, add 3Kg Magnesium Silicate q-agent sorbent material, be warming up to 105 ℃, be evacuated to-0.093MPa nitrogen bubble 3 hours, survey potassium ion, moisture content, carry out circulating filtration after content is qualified, circulate after 30 minutes, potassium (K is surveyed in sampling ⁺), can filter after qualified, in all shifting out after 80-90 minute and still.Experiment 1#-3# is for adding the hydrate system, and 4# is for not adding the hydrate system in experiment, finds out that from data the circulating filtration time that does not add the hydrate system was about 1 hour.Experimental data sees Table:

The experiment number		??1	??2	??3	??4
						Promoter addition	HP add-on Kg	??2941	??3063	??3059	??3083
Water add-on Kg	??6.0	??6.3	??6.2	??14.0
					Water content %		??0.3	??0.3	??0.3	??4.5
Phosphoric acid (85%) add-on Kg	??18.2	??19.5	??19.0	??19.0
					??NaH 2PO 4H 2O?????Kg		??3.0	??3.0	??1.5	??00
Magnesium Silicate q-agent amount Kg	??2.9	??4.5	??2.2	??4.5
					BHT measures Kg		??4.5	??4.5	??4.5	??00
Each section operating time	Add water churning time minute	??10	??10	??10							??30
					In and time minute	??60	??60	??60	??60
	Draw water-93Kpa time minute	??5	??5	??5						??80
					Nitrogen bubble time minute	??180	??180	??180	??180
	Filtration cycle time minute	??30	??30	??30						??100
					Filtration time minute	??80	??90	??90	??70
	Total time minute	??365	??375	??375						??520
					Product analysis	Moisture %	??0.02	??0.02	??0.04		??0.01
Potassium (K +)?????????ppm	??2.2	??2.2	??0.7	??2.5
						??pH	??5.92	??5.92	??5.25	??5.31
Acid number mgKOH/g	??0.047	??0.047	??0.090	??0.230

Claims (3)

1, a kind of polyether glycol process for refining comprises operations such as neutralization, drying and dehydrating, circulating filtration, it is characterized in that:

(1) crude polyoxyalkylene polyol (PPG) is put into and still, be warming up to the 80-90 degree, start stirring, the adding neutralizing agent also reacted 10-30 minute, made pH value of solution=4.8-6, in N-process, the Controlling System water content is below 1.0%, and add inorganic salt hydrate and do crystal seed, phenol derivatives is done precipitation agent, adds sorbent material again; The hydrate add-on is the 0.03-1.0% of PPG, and precipitation agent is the 0.1-0.5% of PPG, and sorbent material is the 0.05-0.2% of PPG;

(2) be warming up to the 95-120 degree, under agitation reacted 30-50 minute, carry out drying and dehydrating again and handle-dehydration by evaporation and feed nitrogen and dry up 150-180 minute under negative pressure;

(3) carry out circulating filtration 0.5-1.0 hour, remove wherein each kind of salt.

2. according to the described polyether glycol process for refining of claim 1, it is characterized in that: the crystal seed hydrate is MgSO ₄H ₂O, MgSO ₄7H ₂O, NaH ₂PO ₃H ₂O, NaH ₂PO ₄12H ₂O, Na ₂SO ₄10H ₂O, KAl (SO ₄) ₂12H ₂O, ZnSO ₄7H ₂O etc. contain the hydrate of a crystal water at least.

3. according to the described polyether glycol process for refining of claim 1, it is characterized in that: the phenol derivatives precipitation agent comprises 2, the 6-di-tert-butyl-4-methy phenol, 1,3,5-trimethylammonium-2,4,6-three (3 ＇, 5 ＇-di-t-butyl)-4-hydroxybenzyl benzene, 2-(2-hydroxyl-3-tertiary butyl benzyl) methyl-phenoxide etc.