CN101024608A - Process for preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas - Google Patents

Abstract

The invention relates to a technology to make fumaric acid. The feature is that benzene anhydride oxidation tail gas spraying acid takes isomerization under effect of thiourea catalyst after removing phthalic acid and decoloring. The invention has the advantages of simple technology, low cost, obvious economic and environment benefits.

Description

The technology of preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas

Technical field

The invention belongs to the fumaric acid technical field, be specifically related to utilize the technology of preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas.

Background technology

It is reported that toxic substance content is phthalic anhydride 200ppm, cis-butenedioic anhydride 100-600ppm, naphthoquinones 10-30ppm, aldehydes 10-100ppm, CO 1000-10000ppm, C0 in the phthalic anhydride waste gas ₂6000-50000ppm.Cui's tear of waste gas is strong, has pungency and smells flavor, and directly discharging can polluted air.

The waste gas processing method that generally adopts has at present: burning method, absorption method.Wherein absorption method mainly contains: reclaim cis-butenedioic anhydride isomerization system fumaric acid method cis-butenedioic anhydride method, the washings from washings.

" chemical industry environmental protection " 2003 the 23rd volumes the 1st intelligent grade of phase 54-56 page or leaf Zhu Xiao " extracting fumaric acid from the phthalic anhydride factory effluent " discloses a kind of technology of being produced fumaric acid by the benzoic anhydride tail-gas absorption liquid: adopt first isomerization, then with activated carbon decolorizing, filtration system fumaric acid.Its catalyzer thiocarbamide and wastewater quality ratio be 1: 300, temperature be 105 ℃ of effects, return times be 2h, gac with wastewater quality than being 1.1-1.3: 100.

Summary of the invention

The technology that the purpose of this invention is to provide a kind of preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas has solved benzene anhydride oxidized tail gas spray sour water and has effluxed the environmental pollution that causes and the problem of the wasting of resources.

Ultimate principle of the present invention is: after the brilliant cooling decolouring of benzene anhydride oxidized tail gas spray sour water, be admitted to the reactive crystallization still, under the effect of certain temperature condition and catalyzer (thiocarbamide), maleic acid in the sour water is converted into FUMARIC ACID TECH GRADE, the FUMARIC ACID TECH GRADE aqueous solution is separated out the FUMARIC ACID TECH GRADE crystal through cooling, through centrifuge dripping, drying makes fumaric acid.Chemical equation is as follows:

The present invention is concrete to adopt following technical scheme to realize:

A kind of technology of preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas is characterized in that, with activated carbon decolorizing afterreaction, crystallization.

The technology of described preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas is characterized in that, comprises the following steps:

1) benzene anhydride oxidized tail gas spray sour water filters through one-level, removes phthalic acid not molten in the sour water, enters the primary acids pond;

2) sour water in primary acids pond cools to 30-50 ℃, remove the phthalic acid of separating out after, sour water is through cascade filtration;

3) pump into 20～40m ³The secondary sour water still of going into to decolour is warming up to 60-80 ℃, adds the gac of 90～120Kg, the flocculating aids of 10～60Kg, continues to be warming up to 90-100 ℃, insulation 0.5-2h;

4) elimination gac, flocculating aids, the thiocarbamide of adding 50～100Kg continues to be heated to 80-100 ℃, insulation 1-3h;

5) be cooled to≤50 ℃, centrifuge dripping, the filtrate decontaminated water is handled, and the thick fumaric acid that obtains gets the finished product fumaric acid after washing, drying.

Described flocculating aids is a diatomite.

Beneficial effect of the present invention is:

1) phthalic acid in the benzene anhydride oxidized tail gas spray sour water has obtained recycling, and only about 200 tons of the phthalic acid year of Hui Shouing, about 1,000,000 yuan of annual income has increased economic benefit of enterprises;

2) maleic acid 98% in the tail gas spray sour water has obtained recycling, and year can be produced 5000 tons/year of FUMARIC ACID TECH GRADE, and remaining mother liquor waste water has entered sewage work, has both increased the economic benefit of company, has eliminated the environmental pollution of sour water again.

3) the dry fluidized-bed vibration drying machine that adopts, steam heating has been avoided the shortcoming that time of drying is long in the old technology baking oven for heating drying, the bulk material is many, labour intensity is big; Centrigugal swing dryer adopts blowdown whizzer under the tripodia automatic scraper, and control automatically, automatic drying, automatic scraper have shortened the operational cycle, have alleviated working strength of workers.

4) steam condensation water after the steam heating returns water pot with fixed attention, and squeezes into the soft water storage tank, and behind the adding medicament, the supply boiler uses again, and steam condensation water has obtained comprehensive utilization.

5) method of prior art is in the process of high temperature decolouring, can produce a lot of viscous substances, when filtering, viscous substance is often stuck with paste and is attached on the filter cloth, promptly use very big pressure also to be difficult to filter, and the applicant find, behind the interpolation flocculating aids diatomite, gac and diatomite can form bridge joint, make to filter to become relatively easy.

Embodiment

Embodiment 1

Filter through one-level from phthalic anhydride plant spray sour water, remove phthalic acid not molten in the sour water, enter the primary acids pond, the sour water in primary acids pond is pumped into the cooling still through sour water, through cooling 35 ℃, most phthalic acid is separated out at this, separates out sour water behind the phthalic acid through cascade filtration, remove the phthalic acid of separating out, filtrate enters secondary sour water pond.The sour water filtering purpose of lowering the temperature is in order to remove the phthalic acid in the sour water, improves the purity of fumaric acid, and the phthalic acid of recovery is sold as byproduct after airing.

Remove sour water behind the phthalic acid through being pumped into the decolouring still, can pump into sour water, and meanwhile logical steam, when the amount of pumping into is 25m ³The time, stop to pump into, continue heating and start to stir, when temperature rises to 65 ℃, add gac 60kg for the decolouring still, diatomite 10-60Kg continues to be warming up to about 100 ℃, insulation 1h, and the sour water in the still that will decolour then is pumped into filtering system and precoating circulating filtration through press filtration, treat by visor observe to filter feed liquid limpid after, pour limpid feed liquid into the reactive crystallization still,, start to stir and add thiocarbamide 60kg when crystallization kettle sour water during to volumetrical 1/3-1/2, after treating that material has been beaten, continue heating, make temperature in the kettle rise to 90 ℃, insulation 2.5h, the water flowing cooling, make temperature in the kettle reduce to 50 ℃, cooling fluid is put into centrigugal swing dryer, carry out centrifuge dripping, filtrate enters sour water mother liquor pond, the sour water mother liquor enters sewage work, and the thick sour regurgitation that obtains is through washing, make smart fumaric acid after the drying, fumaric acid measures as product, packing, sell.

Embodiment 2-8: basic identical with embodiment, just processing parameter is according to table 1.

The processing parameter of table 1 embodiment 2-8

Embodiment		2	3	4	6	7	8
								Proportioning raw materials	The secondary sour water, m 3	20	20	30	30	40	40
Gac, Kg	70	80	90	100	110	120
							Diatomite, Kg		20	30	40	50	60	60
Thiocarbamide, Kg	60	70	80	90	95	100
							Processing parameter		Remove and face the phthalic acid temperature, ℃	30	40	45	50	55	60
Add the gac temperature, ℃	60	70	75	80	75	65
								Bleaching temperature and time, ℃/h	90/2	90/1.5	95/1.5	95/1	100/1	100/0.5
Isomerisation temperature and time, ℃/h	80/3	85/3	90/2	95/2	100/1	100/1
								Knot product temperature, ℃	50	48	45	40	35	30

Claims (3)

1. the technology of a preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas is characterized in that, uses the activated carbon decolorizing afterreaction, crystallization.

2. the technology of preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas according to claim 1 is characterized in that, comprises the following steps:

1) benzene anhydride oxidized tail gas spray sour water filters through one-level, removes phthalic acid not molten in the sour water, enters the primary acids pond;

2) sour water in primary acids pond cools to 30-50 ℃, remove the phthalic acid of separating out after, the sour water cascade filtration;

3) pump into 20～40m ³The secondary sour water still of going into to decolour is warming up to 60-80 ℃, adds the gac of 90～120Kg, the flocculating aids of 10～60Kg, continues to be warming up to 90-100 ℃, insulation 0.5-2h;

4) elimination gac, flocculating aids, the thiocarbamide of adding 50～100Kg continues to be heated to 80-100 ℃, insulation 1-3h;

5) be cooled to≤50 ℃, centrifuge dripping, the filtrate decontaminated water is handled, and the thick fumaric acid that obtains gets the finished product fumaric acid after washing, drying.

3. the technology of preparing fumaric acid by spraying acid water to benzene anhydride oxidized tail gas according to claim 2 is characterized in that, flocculating aids is a diatomite.