CN1508067A - Method for preparing active carbon by oxidation of residue using terephthalic acid - Google Patents
Method for preparing active carbon by oxidation of residue using terephthalic acid Download PDFInfo
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- CN1508067A CN1508067A CNA021485933A CN02148593A CN1508067A CN 1508067 A CN1508067 A CN 1508067A CN A021485933 A CNA021485933 A CN A021485933A CN 02148593 A CN02148593 A CN 02148593A CN 1508067 A CN1508067 A CN 1508067A
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Abstract
The method for preparing active carbon by using P-phthalic acid oxidation residue includes the following steps: utilizing calcification to make the oxidation residue into oxidation esidue calcium salt, making the oxidation residue calcium salt undergo the process of carbonation treatment under the condition of isolating air or under-oxygen atmosphere to obtain porous powder active carbon, then using acid to wash the soluble metal salt (mainly it is calcium carbonate), drying so as to obtain final powder active carbon product which can be used for making sewage treatment, also can be used as rubber filling agent, decolouring agent or catalyst carrier.
Description
Technical field
The present invention relates to a kind of manufacture method of gac, is a kind ofly to prepare process of active carbon by the terephthalic acid oxidation residua specifically.
Background technology
Pure terephthalic acid's (being called for short PTA) is the important source material of polyester industrial.The pure terephthalic acid by to toluene through oxidation, make.Except that generating the principal product terephthalic acid, still there is multiple by product to generate in the oxidizing reaction.In order to guarantee the quality of PTA product, prevent that some objectionable impurities from accumulating in production system, need at the regular exhaust catalyst solution of oxidation unit-oxidation residua mother liquor.The oxidation residua mother liquor obtains a solid residue (hereinafter to be referred as oxidation residua I) after reclaiming acetate solvate and Cobaltous diacetate Mn catalyst.The composition of oxidation residua has phenylformic acid, p-methylbenzoic acid, phthalic acid, terephthalic acid, m-phthalic acid and to kind of compound surplus carboxyl phenylformic acid etc. 30.Oxidation residua I is remaining residue after carrying most phenylformic acid, is called oxidation residua II.The oxidation residua quantity I of the annual discharging of large-scale PTA production equipment is considerable.A factory that produces 400000 tons of terephthalic acids per year needs the discharging oxidation residua at the 5000-10000 ton in year.
During U.S. AMOCO company is original design, oxidation residua all is to fall as a kind of waste is processed, the method of handling mainly is with its burning, the weak point of this processing mode has: about 90% composition is useful benzoic acids and phthalic acid compounds in (1) waste residue, in burning process, just fill and do fuel, do not bring into play its due use value; (2) waste residue burning difficulty, it is combustion-supporting to add liquefied gas.In addition, because residue carbon content height, it is insufficient to burn, thereby causes air environmental pollution, is unfavorable for environment protection.
Another kind method is that oxidation residua is joined in the PTA waste water, is handled by the PTA sink drainage.The main drawback that sink drainage is handled is to take up an area of greatly, and power consumption is big.For the China that has a large population and a few land, obviously improper.
China to the main mode of the utilization of oxidation residua II is at present: the phenylformic acid in the residue, p-methylbenzoic acid are removed by filter filter residue and drying with the hot water dissolving.The part purposes that can replace original terephthalic acid and phthalic acid with this slag---softening agent, unsaturated polyester, Synolac (coating, tackiness agent), but the color of its product is darker, sells to differ, and is adapted at requiring low occasion to use to form and aspect.And a large amount of easily long-term accumulations of oxidation residua become the rubbish that is difficult to handle, seriously contaminate environment.So press for the technology of a kind of energy of exploitation mass consumption oxidation residua.
Summary of the invention
The technical problem to be solved in the present invention be exactly the technology of the oxidation residua that produces of existing processing para-phthalic acid (pta) otherwise take up an area of big, power consumption is big, or causes environmental pollution problems easily.
For addressing the above problem, basic technical scheme of the present invention is by calcification oxidation residua to be made the oxidation residua calcium salt, and the oxidation residua calcium salt with drying carries out carbonization under secluding air or oxygen debt atmosphere again.
Above-mentioned calcification process is oxidation residua direct and calcification agent reaction when water or anhydrous the existence are arranged, and its its condition of detailed process step is as follows:
1,------oxidation residua and calcic raw material reaction are made calcium salt to calcify reaction.
Earlier oxidation residua, water are joined in the reactor of stirring.The add-on of water is oxidation residua and calcification agent cumulative volume 0～10 times, preferably 2～5 times.Stirring, the oxidation residua water suspension is heated to temperature required, generally is 50-90 ℃, adds the calcification agent then in batches and reacts.After a collection of calcification agent of every adding several minutes, check the pH value of solution.When pH value arrived 8～9, reaction finished substantially, only has the particle neutral oxidation residua that is in of minute quantity also not have calcification.This moment, calcification process can finish, and also can be incubated the ageing certain hour, generally at 0-5 hour, checked pH value again.Drop to below 7 as pH value, should add an amount of calcification agent, be generally the 0.5-5% that adds calcification agent gross weight, react again after 0-1.5 hour and finish.After calcify reaction is finished, carry out solid-liquid separation with filtration or decant method, filtrate is used when next calcification; Filtration cakes torrefaction gets calcification material 1, and is standby.
Above-mentioned calcification agent is unslaked lime (CaO), white lime (Ca (OH)
2), one or more the mixture in the lime carbonate (CaCO3).Described soluble calcium salt is calcium chloride or nitrocalcite.When selecting unslaked lime (CaO) or white lime (Ca (OH) for use
2) time, the required temperature of calcification is 0-180 ℃, when selecting for use lime carbonate (CaCO3) fine powder to be the calcification agent, calcification is temperature required should be greater than 50 ℃, preferably about 80 ℃.
Need to prove,, before being less than carbonization temperature, volatilize because most of compositions of oxidation residua all have volatility, can't be directly with its carbonization.Must be made into more stable metal-salt.There is multiple metal-salt to select.But from economic considerations, has only the most cheap, the most convenient of originating of calcium, so the present invention only selects the intermediate raw material of oxidation residua calcium salt as carbonization for use.
When calcification, also can be earlier oxidation residua to be made the solubility calcium salts solution, again with soluble calcium salt such as calcium chloride or nitrocalcite.Reaction.
2, carburizing reagent
Because carbonization is more than 530 ℃, generally at 530-1000 ℃, under this high temperature, carbon can cause the loss of carbon with oxygen in the gas phase, water vapour reaction, thereby oxygen, water vapour are deleterious gas to carbonization process.Under too high obnoxious flavour, even can not get carbon.And carbonization process itself produces a large amount of gas, thereby carbonized stock can not be sealed fully, must leave certain air outlet.Otherwise the danger of the blast of producing is arranged; Simultaneously guarantee that again obnoxious flavour does not contact with the activated carbon of oxidation residua calcium salt, harsh one-tenth.Thereby carbonization should be carried out under secluding air or oxygen debt atmosphere.So-called oxygen debt atmosphere is meant that the residing space of carbonized stock secluding air is good in carbonization process, do not have a large amount of oxygen to enter, perhaps come secluding air with the rare gas element that feeds capacity such as the method for nitrogen, carbonic acid gas, argon gas, neon, helium and their mixture.Thereby carbonization is a kind of way easily in nitrogen.Carbonization must be contained in the oxidation residua calcium salt in the container that the gas that can stop air admission, can allow reaction produce again discharges in air.Reasonable as the carbonization Vessel Design, this is a kind of more convenient more economical way.
Calcification material 1 makes promptly that to contain ash be the more activated carbon of calcium cpd 1 after above-mentioned carburizing reagent, its ash oontent is generally more than 70%.
3, pickling ash disposal
Will be through high ash content activated carbon 1 that above-mentioned two steps make and water by weight 1: the ratio of 5-15 joins in the container of stirring and stirs, to activated carbon by water fully moistening after, drip acid solution.Should control rate of addition when dripping acid solution, overflow in order to avoid gas-liquid emulsification is serious.Because the solubleness of calcium salt in water of sulfuric acid, phosphoric acid is little, the effect of ash disposal is bad, can not use.And the calcium salt of nitric acid, hydrochloric acid, acetic acid has bigger solubleness in water, can use.Acetic acid is fine to the wettability of activated carbon, adds a certain amount of acetic acid between humid period, can accelerate moistening process.Sour consumption is determined according to the alkali equivalent of the activated carbon of measuring in the reaction process, determine that mode is to calibrate 0.1N NaOH with primary standard reagent potassium hydrogen phthalate, calibrate the right value of 0.1N hydrochloric acid with this NaOH, calibrate the alkali equivalent of gac with this 0.1N hydrochloric acid.After reaction is finished, use the deionized water filtration washing repeatedly.Washing times is determined according to the required ash oontent of activated carbon.The deionized water wash of the 3-5 of general usefulness activated carbon volume 4-5 time.120 ℃ of oven dry of activated carbon with after the washing promptly obtain desired product.
This step mainly be for the ash content removed in the activated carbon be lime carbonate, but be used as low-grade purposes as activated carbon, as sewage disposal carbon, loading material of rubber carbon, some neutrality, micro alkaline solution decolorization carbon, lime carbonate in the activated carbon need not to remove, and therefore can not need carry out this treatment step.
Referring to accompanying drawing 1, oxidation residua calcium salt (calcification material 1) contains the calcium cpd more than 70% in the activated carbon 1 that the first time, carbonization obtained, its also a kind of spendable calcification agent.Do the calcification agent with activated carbon 1, carbon content obviously rises in the activated carbon 3 that obtains.Can save the sour consumption of next step pickling like this.Consider that from economy doing the calcification agent with activated carbon 1 is suitable selection.Because activated carbon 1 is done the calcification agent, oxidation residua enters in the hole of activated carbon 1 and carries out calcification in the calcification process, is the reaction of a volume-diminished, and the volume of the activated carbon 1 that the volume of calcification material 2 equals to add guarantees the processing power of carbonization process.Calcification material 2 carbon content in the activated carbon 3 that carbonization obtains rises nearly one times.As do calcification agent (not drawing in the schema) with activated carbon 3, volume-diminished is not obvious in the calcification process, and the processing power of carbonization process descends, but carbon content further rises in the activated carbon.Activated carbon 1 need actually through how many times (0～n, n-1,2,3 ...) calcification, carbonization, need to decide according to economy, the character of activated carbon, the purposes of process.
As doing the calcification agent with lime carbonate or activated carbon (activated carbon 1, activated carbon 3 in the schema), the pH value that is difficult to the detection reaction process changes, need to measure oxidation residua and calcification agent (lime carbonate, activated carbon) soda acid equivalent (mol/g) with the acid base titration method earlier, determine the ratio and the consumption of two raw materials again according to the equivalent of two raw materials.General calcification agent is excessive slightly.The mol ratio of oxidation residua and calcification agent is 1: 1～1.05.The calcification agent is excessive slightly to be for the abundant calcification of oxidation residua.
Temperature of reaction has certain influence to the settling property of product.During reaction (the calcification agent is milk of lime or unslaked lime) at room temperature, the product exquisiteness, filtering has certain resistance; Reaction about 80 ℃, product is quicksand like, and precipitation is deposited in beaker bottom a little, just can isolate product with decantation.
As doing the calcification agent with lime carbonate or activated carbon, react slower under the room temperature, generally be heated to more than 40 ℃, as be heated to more than 80 ℃.To guarantee that calcification process has a rational speed.
In last figure, activated carbon 1 can continue to obtain calcification material 2 with oxidation residua reaction, and 2 carbonizations of calcification material get activated carbon 3; Activated carbon 3 can continue to obtain calcification material 3 with oxidation residua reaction: 3 carbonizations of calcification material get activated carbon 5, and activated carbon 5 pickling ash disposal get activated carbon 6; Activated carbon 5 can continue to obtain calcification material 4 with oxidation residua reaction ..., this process can circulate down always
Oxidation residua raw material of the present invention is the oxidation residua I of the oxidation residua mother liquor of discharging in Production of Terephthalic Acid process gained after reclaiming acetic acid, cobalt, manganese element, also can be behind the part phenylformic acid that further reclaims in the oxidation residua 1 gained to oxidation residua II.
The former burning process temperature of combustion of carbonization temperature of the present invention and AMOCO is compared, and is much lower, can save a large amount of fuel, and can obtain a large amount of useful activated carbon, can be used for industries such as sewage disposal, rubber filler.
The PTA sewage disposal of the present invention and AMOCO technology is compared, and takes up an area of to lack, and power consumption is few, and can obtain a large amount of useful activated carbon, can be used for industries such as sewage disposal, rubber filler.
The activated carbon that the present invention makes also can be as the discoloring agent or the support of the catalyst of other industry.
Description of drawings
Fig. 1 is a process flow sheet of the present invention
Fig. 2 is that first row carries out the synoptic diagram that pore structure characterizes in the gac table one for preparing among the embodiment one.
Embodiment
Embodiment one:
1, add 300ml water in the 1000mi beaker, about 300g oxidation residua II stirs and heats.When temperature is raised to 80 ℃, add through the filtering milk of lime of 40 mesh sieves in batches, arrive pH value greater than 9.After the insulated and stirred 1 hour, check pH value again, pH value is added milk of lime about 7, and insulated and stirred is 1 hour again.Precipitate half an hour, remove upper strata thin liquid (reusable during next calcification) with decantation (also available filtration method), lower floor's solid is dried under 100-120 ℃, and is standby.
2, add 70ml water in the 200ml beaker, 20g oxidation residua II stirs and heats.When temperature is raised to 80 ℃, add pure by analysis lime carbonate fine powder 11.8g.Insulated and stirred 3 hours, with removing by filter water, filter cake is dried at 100-120 ℃.
3, get the calcium salt that above-mentioned steps 1,2 is made, in two stainless steel vessels of packing into, be warming up to 640 ℃ in nitrogen, constant temperature half an hour, take out the cold back of getting.Wash with dilute acetic acid that lime carbonate fully dissolves to the charcoal.Be washed till neutrality with deionized water again, drying gets gac.Concrete data are as follows:
Table one:
| The calcium salt source | The calcium salt add-on | Activated carbon 1 weight | Calcification agent kind | Gac weight | The gac yield |
| Step 1 | ??13.056g | ??7.386g | Milk of lime | ??1.740g | ??13.33％ |
| Step 2 | ??13.707g | ??8.132g | Lime carbonate | ??1.986g | ??14.49％ |
Can find from last table, be more or less the same with different calcification agent gac yield.
Embodiment two:
250 ℃ of dryings 12 hours, with method therefor calcification among the embodiment one, the calcium salt of gained dried to constant weight under 300 ℃ with oxidation residua II, took out to place moisture eliminator standby.Get respectively about 9 grams again and be added in three quartz crucibles, carbonization is to constant weight (air atmosphere) in chamber type electric resistance furnace under 585 ℃, 600 ℃, 615 ℃, and gac 1 yield (gac 1 weight/reinforced weight) is respectively 69.9%, 70.6%, 69.5%.
Embodiment three:
Get oxidation residua calcium salt (embodiment one) 20.01g, in the stainless steel vessel of packing into, under the condition of secluding air, be warming up to 830 ℃, constant temperature three hours.At this moment, the calcium in the activated carbon 1 exists with the form of calcium oxide.The cooling back is extremely neutral with a large amount of deionized water repetitive scrubbings, to remove calcium hydroxide.Get gac 2.71 grams.
Embodiment four:
Get the activated carbon I20 gram of gained among the embodiment two, get oxidation residua made among the embodiment two 23.25 grams, place the 500ML beaker, add entry 250ML, stir, be warming up to 50-80 ℃ and reacted 2 hours down, filter, oven dry 600 ℃ of following carbonizations, gets activated carbon III26.01 gram.Through pickling, washing, oven dry, get activated carbon 12.0 grams.
Embodiment five
Get oxidation residua 1 300 grams, make calcium salt with the method for embodiment one, 120 ℃ of oven dry.Get 20 gram calcium salts, carbonization is 1 hour in 600 ℃ of following nitrogen, gets activated carbon 1 11.1 grams respectively.
Claims (15)
1, a kind ofly prepares active carbon method, it is characterized in that it is by calcification oxidation residua to be made the oxidation residua calcium salt, carries out carbonization with the oxidation residua calcium salt again under secluding air or oxygen debt atmosphere with the terephthalic acid oxidation residua.
2, according to claim 1ly prepare active carbon method with the terephthalic acid oxidation residua, it is characterized in that calcification process can be directly direct and calcification agent reaction when having water to exist of oxidation residua, also can earlier oxidation residua be made soluble salt solution, again with the solubility calcium reactant salt.
3, according to claim 2ly prepare active carbon method with the terephthalic acid oxidation residua, it is characterized in that oxidation residua directly when having water to exist directly and during calcification agent reaction the add-on of water be oxidation residua and calcification agent cumulative volume 0-10 times.
4, according to claim 3ly prepare active carbon method with the terephthalic acid oxidation residua, the add-on that it is characterized in that water be oxidation residua and calcification agent cumulative volume 2-5 doubly.
5, prepare active carbon method according to according to claim 2 with the terephthalic acid oxidation residua, the calcification agent adds in batches when it is characterized in that calcification, check the pH value of solution behind a collection of calcification agent of the every adding number minute, when pH value reached 8-9, calcification process finished substantially.
6, prepare active carbon method according to according to claim 5 with the terephthalic acid oxidation residua, when it is characterized in that calcification when the pH value that detects solution reaches 8-9, can be incubated the ageing certain hour, the pH value of test solution again, reduce to 7 when following as pH value, should add the calcification agent, again calcify reaction for some time.
7, according to claim 2ly prepare active carbon method, it is characterized in that described calcification agent is unslaked lime (CaO), white lime (Ca (OH) with the terephthalic acid oxidation residua
2), one or more the mixture in the lime carbonate (CaCO3); Described soluble calcium salt is calcium chloride or nitrocalcite.
8, according to claim 7ly prepare active carbon method, it is characterized in that the calcification agent is unslaked lime (CaO) or white lime (Ca (OH) with the terephthalic acid oxidation residua
2) time, the required temperature of calcification is about 0-100 ℃.
9, according to claim 7ly prepare active carbon method, it is characterized in that the calcification agent is for being lime carbonate (CaCO with the terephthalic acid oxidation residua
3) during fine powder, the required temperature of calcification is greater than 50 ℃.
10, according to claim 1ly prepare active carbon method with the terephthalic acid oxidation residua, temperature is 530～1000 ℃ when it is characterized in that carbonization.
11, according to claim 1ly prepare active carbon method with the terephthalic acid oxidation residua, it is characterized in that described oxygen debt atmosphere is meant that the residing space of carbonized stock secluding air is good in carbonization process, do not have a large amount of oxygen to enter, perhaps come secluding air with the method for the rare gas element that feeds capacity.
12, according to claim 1ly prepare active carbon method, it is characterized in that also comprising a pickling ash disposal process after the carbonization, promptly the ash content in the activated carbon that generates after the carbonization is removed with acid with the terephthalic acid oxidation residua.
13, according to claim 11ly prepare active carbon method with the terephthalic acid oxidation residua, it is characterized in that the pickling ash disposal be the activated carbon that will generate after the carbonization and water by weight 1: the ratio of 5-15 adds in the container that stirring is arranged and stirs, to activated carbon by water fully moistening after, drip acid solution; After reaction is finished, use the deionized water filtration washing repeatedly, 120 ℃ of oven dry of the activated carbon after will washing at last.
14, according to claim 12ly prepare active carbon method, it is characterized in that the used acid of pickling ash disposal is nitric acid or hydrochloric acid or acetic acid with the terephthalic acid oxidation residua.
15, according to claim 12ly prepare active carbon method with the terephthalic acid oxidation residua, when it is characterized in that filtration washing with the consumption of deionized water be the activated carbon volume 3-5 doubly, the number of times of washing is determined according to the required ash oontent of activated carbon.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101837967B (en) * | 2009-03-19 | 2012-07-18 | 清华大学 | Method for preparing carbon composite material |
| CN103754867A (en) * | 2013-12-05 | 2014-04-30 | 上海大学 | Method for preparing active carbon by utilizing high-COD organic wastewater in alkali deweighing technology of dyeing plant |
| CN111097399A (en) * | 2019-10-14 | 2020-05-05 | 岳托科技（北京）有限公司 | Magnetic charcoal catalyst prepared from PTA residues and advanced oxidation water treatment method thereof |
| CN115536021A (en) * | 2022-10-27 | 2022-12-30 | 东华大学 | Terephthalic acid printing and dyeing white mud activated carbon and preparation method thereof |
-
2002
- 2002-12-20 CN CNA021485933A patent/CN1508067A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101837967B (en) * | 2009-03-19 | 2012-07-18 | 清华大学 | Method for preparing carbon composite material |
| CN103754867A (en) * | 2013-12-05 | 2014-04-30 | 上海大学 | Method for preparing active carbon by utilizing high-COD organic wastewater in alkali deweighing technology of dyeing plant |
| CN111097399A (en) * | 2019-10-14 | 2020-05-05 | 岳托科技（北京）有限公司 | Magnetic charcoal catalyst prepared from PTA residues and advanced oxidation water treatment method thereof |
| CN115536021A (en) * | 2022-10-27 | 2022-12-30 | 东华大学 | Terephthalic acid printing and dyeing white mud activated carbon and preparation method thereof |
| CN115536021B (en) * | 2022-10-27 | 2023-08-22 | 东华大学 | Terephthalic acid printing and dyeing white mud activated carbon and preparation method thereof |
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