The utility model content
In order to overcome the defects of prior art, the nothing that the utility model provides a kind of KPTA of being suitable for to produce stirs oxidation and deep oxidation reaction system, and this system need not the slurry in the reaction unit is carried out mechanical agitation, and device structure is simplified, consuming little energy, easy to operate.
The utility model realizes that the technical scheme that above-mentioned purpose adopts is:
A kind of nothing that is suitable for KPTA production stirs oxidation and deep oxidation reaction system, it comprises the oxidation reactor that connects successively, discharge tank and deep oxidation reaction unit, described deep oxidation reaction unit is single deep oxidization reactor or is comprised of the deep oxidization reactor I and the deep oxidization reactor II that connect successively, described oxidation reactor, discharge tank, single deep oxidization reactor, deep oxidization reactor I and deep oxidization reactor II all adopt air inlet to be positioned at the bubble tower structure of bottom, when described deep oxidation reaction unit is described single deep oxidization reactor, the slurry import of described single deep oxidization reactor consists of the slurry import of described deep oxidation reaction unit, and the slurry outlet of described single deep oxidization reactor consists of the slurry outlet of described deep oxidation reaction unit; When described deep oxidation reaction unit is comprised of the described deep oxidization reactor I that connects successively and deep oxidization reactor II, the slurry import of described deep oxidization reactor I consists of the slurry import of described deep oxidation reaction unit, and the slurry outlet of described deep oxidization reactor II consists of the slurry outlet of described deep oxidation reaction unit.
The beneficial effects of the utility model are: because described oxidation reactor, each deep oxidization reactor of discharge tank and composition deep oxidation reaction unit has all adopted the bubble tower structure, pass into the required oxygen-containing gas of oxidation reaction from the air inlet that is positioned at the bubble tower bottom, by these reacting gas the slurry in each autoreactor (comprising the discharge tank that can play the oxidation reaction effect) is mixed, realized that oxygen is with the effective contact between other reactant, when having saved mixing plant, effectively prevented the precipitation of suspended nitride, improved the gas content in the reaction liquid phase, be conducive to improve the efficient of oxidation reaction, simplified thus device structure, reduced equipment investment, measuring and calculating according to the applicant, for the system of megaton, can reduce 4,000 ten thousand yuan of equipment investments, reduce power consumption 1000kwh/h.
Owing between oxidation reaction and deep oxidation reaction, be provided with discharge tank, and can pass into oxygen-containing gas by the air inlet of discharge tank bottom, make the slurry that enters discharge tank be able in discharge tank, carry out oxidation reaction, namely realized the oxidation rear oxidation, not only being conducive to anti-oxidation discharging by discharge tank is short-circuited, but also improved oxidation effectiveness, be conducive to alleviate follow-up deep oxidation reaction requirement, simultaneously can also be according to the intermediate product characteristic in the slurry, reasonably set out the reaction condition of the oxidation rear oxidation in the charging basket, and by with the Collaborative Control of oxidation reactor, in handled easily, make W-response flow process and reaction condition more reasonable.
The specific embodiment
Referring to Fig. 2-3, the nothing that the utility model provides a kind of KPTA of being suitable for to produce stirs oxidation and deep oxidation reaction system, it comprises the oxidation reactor 1 that connects successively, discharge tank 19 and deep oxidation reaction unit, described deep oxidation reaction unit is single deep oxidization reactor 21 or is comprised of the deep oxidization reactor I11 and the deep oxidization reactor II10 that connect successively, described oxidation reactor, discharge tank, single deep oxidization reactor, deep oxidization reactor I and deep oxidization reactor II all adopt air inlet to be positioned at the bubble tower structure of bottom, when described deep oxidation reaction unit is described single deep oxidization reactor, the slurry import of described single deep oxidization reactor consists of the slurry import of described deep oxidation reaction unit, and the slurry outlet of described single deep oxidization reactor consists of the slurry outlet of described deep oxidation reaction unit; When described deep oxidation reaction unit is comprised of the described deep oxidization reactor I that connects successively and deep oxidization reactor II, the slurry import of described deep oxidization reactor I consists of the slurry import of described deep oxidation reaction unit, and the slurry outlet of described deep oxidization reactor II consists of the slurry outlet of described deep oxidation reaction unit.Described each reactor (comprises oxidation reactor, discharge tank and deep oxidization reactor) air inlet connects corresponding oxygen-containing gas pipeline, described oxygen-containing gas enters described oxidation reactor from corresponding described air inlet, discharge tank, behind the deep oxidization reactor (single deep oxidization reactor or deep oxidization reactor I and deep oxidization reactor II), at described oxidation reactor, the bottom bubbling of discharge tank and deep oxidization reactor is mixed slurry, to impel the solid suspension in the described slurry under the mixing of oxygen-containing gas, not precipitate, so that described discharge tank, single deep oxidization reactor, the intermediate oxidation product and the oxygen that comprise PT acid and 4-CBA in the slurry in deep oxidization reactor I and the deep oxidization reactor II are proceeded oxidation reaction.
Preferably, the draw ratio of described discharge tank can be 6~10, the draw ratio of described single deep oxidization reactor, described deep oxidization reactor I and described deep oxidization reactor II can be all in 5~8 scope, each reactor according to this design of Structural Parameters, be conducive to improve the effect of mixing of oxygen-containing gas, can the most effectively optimize the oxidizing process in each reactor, simplified apparatus structure and operating cost.
Preferably, the volume of described discharge tank is 10~15% of described oxidation reactor, the volume of described single deep oxidization reactor is 70~80% of described oxidation reactor, and the volume sum of described deep oxidization reactor I and deep oxidization reactor II is 70~80% of described oxidation reactor.Adopt this structural parameters, be conducive to the course of reaction in each reactor of reasonable distribution.
Usually, the slurry import of described discharge tank can be positioned at its middle part, the slurry outlet of described oxidation reactor can be positioned at its bottom, the slurry import of described discharge tank connects the slurry outlet of described oxidation reactor by the discharge tank feed pipe, to realize that slurry is by the conveying of described oxidation reactor to described discharge tank, the top of described discharge tank can be provided with the tail gas outlet, the tail gas outlet of described discharge tank accesses the liquid phase region of described oxidation reactor by the discharge tank exhaust pipe, on the described discharge tank exhaust pipe preferably with inverted U-shaped.
The slurry outlet of described discharge tank connects the slurry import of described deep oxidation reaction unit by the discharge tank discharge pipe, the control valve 4 that described discharge tank discharge pipe is provided with slurry heater 7 and is controlled by the liquid level of described oxidation reactor, control the slurry of described discharge tank discharges according to the liquid level of described oxidation reactor, described slurry heater is steam heater, its heat release medium import and export is serially connected on the jet chimney of heating usefulness, and its heat-absorbing medium import and export is serially connected on the described discharge tank discharge pipe.
Can be provided with the temperature controlled control valve by described deep oxidization reactor I on the described steam pipeline (trace), control the heat that adds of described slurry heater according to the temperature of described deep oxidization reactor I.
Preferably, the air inlet of described discharge tank can comprise compressed air inlet and the import of deep oxidation tail gas, described compressed air inlet connects compressed air piping 2 or air compressor machine, the import of described deep oxidation tail gas connects the deep oxidation tail gas outlet of described deep oxidation reaction unit by deep oxidation exhaust pipe 13, when described deep oxidation reaction unit is described single deep oxidization reactor, described deep oxidation tail gas outlet is arranged on the top of described single deep oxidization reactor, and described deep oxidation exhaust pipe is provided with by the pressure controlled control valve 20 in the described single deep oxidization reactor; When described deep oxidation reaction unit is comprised of the described deep oxidization reactor I that connects successively and deep oxidization reactor II, described deep oxidation tail gas outlet is arranged on the top of described deep oxidization reactor II, and described deep oxidation exhaust pipe is provided with by the pressure controlled control valve 13 in the described deep oxidization reactor II.Thus, can control according to the pressure in described single deep oxidization reactor or the described deep oxidization reactor II discharge of described deep oxidation tail gas, and by the reaction temperature in the pressure control reactor.
Be provided with deep oxidation exhaust gas heat exchanger 12 between described deep oxidation exhaust pipe and the described deep oxidation tail gas outlet, when being provided with described deep oxidation exhaust gas heat exchanger, described deep oxidation exhaust pipe connects the heat release media outlet of described deep oxidation exhaust gas heat exchanger, described deep oxidation tail gas outlet connects the heat release medium import of described deep oxidation exhaust gas heat exchanger, the heat-absorbing medium import of described deep oxidation exhaust gas heat exchanger connects the steam condensate pipe, and the heat-absorbing medium outlet of described deep oxidation exhaust gas heat exchanger connects the by-product vapor pipe.
Preferably, the air inlet of described deep oxidation reaction unit can be connected with pressurization gas pipeline 5 usually, described pressurization gas pipeline connects the outlet of the compressor 3 that is used for gas boosting, the air inlet of described compressor connects the oxidation reactor tail gas output channel 18 after compressed air piping and the purification, when described deep oxidation reaction unit was described single deep oxidization reactor, the air inlet of described single deep oxidization reactor consisted of the air inlet of described deep oxidization reactor; When described deep oxidation reaction unit was comprised of the described deep oxidization reactor I that connects successively and deep oxidization reactor II, the air inlet of described deep oxidization reactor I consisted of the air inlet of described deep oxidation reaction unit.
Preferably, the slurry outlet of described deep oxidization reactor I bottom is sent into the slurry import at described deep oxidization reactor II middle part by the slurry discharge pipe of deep oxidation I, the slurry discharge pipe of described deep oxidation I is provided with the control valve 8 by the liquid level control of described deep oxidization reactor I, the top of described deep oxidization reactor I is provided with the tail gas outlet of deep oxidation I, the tail gas of described deep oxidation I exports the air inlet that connects described deep oxidization reactor II bottom by the exhaust emission tube of deep oxidation I, and the exhaust emission tube of described deep oxidation I is provided with the pressure controlled control valve 14 by described deep oxidization reactor I.
The slurry outlet of described deep oxidation device connects deep oxidation slurry discharge pipe, when described deep oxidation reaction unit is described single deep oxidization reactor, the slurry outlet of described single deep oxidization reactor is positioned at its bottom, and described deep oxidation slurry discharge pipe is provided with the control valve 9 by the liquid level control of described single deep oxidization reactor; When described deep oxidation reaction unit is comprised of the described deep oxidization reactor I that connects successively and deep oxidization reactor II, the slurry outlet of described deep oxidization reactor II is arranged on its bottom, and described deep oxidation slurry discharge pipe is provided with the control valve 9 by the liquid level control of described deep oxidization reactor II.
The top of described oxidation reactor is provided with the oxidized tail gas discharge pipe, be provided with successively oxidized tail gas heat exchanger and oxidized tail gas knockout drum on the described oxidized tail gas discharge pipe, described oxidized tail gas discharge pipe accesses the tail gas outlet access oxidized tail gas knockout drum 15 of condenser system 16 and gas-liquid tail gas knockout drum successively, gas output tube road access oxidized tail gas clarifier 17 after the separation of described oxidized tail gas knockout drum, tail gas connects each equipment for reclaiming by the cleaning of off-gas pipeline after the purification that described oxidized tail gas clarifier is discharged.
The utility model reacts from the oxidation reaction to the deep oxidation and relates to the overall process that is generated TA by the PX oxidation, go through many in the middle of chemical reactions, its key reaction process is as shown in Figure 1, the activation energy of each intermediate reaction is as follows:
K1---PX oxidation generates the TALD(p-tolyl aldehyde), activation energy 65kJ/mol
K2---TALD oxidation generates PT acid (p-methylbenzoic acid), activation energy 51.5kJ/mol
K3---PT acid oxidase generates 4-CBA(to carboxyl benzaldehyde), activation energy 85.1kJ/mol
K4---4-CBA oxidation generates the TA(terephthalic acid (TPA)), activation energy 78.3kJ/mol
From reacting complexity, first and second step reaction speed is the fastest, and the 3rd goes on foot PT acid generation 4-CBA reacts the slowest, and it is also relatively easy that the 4th step 4-CBA further reacts generation TA.So, oxidation reaction discharge in the slurry contained PT acid at most (~9000ppm) because PT acid is soluble in HAC, so PT acid mostly is present in the liquid phase in the slurry.Although 4-CBA content only has~4000ppm in the reaction paste, owing to the cocrystallization reason, 4-CBA is present in solid phase mostly.The deep oxidation reaction is exactly to make the PT acid oxidase generate 4-CBA, and 4-CBA further oxidation generates TA.Obviously, because the 4-CBA major part is present in solid phase, wants further oxidation, and 4-CBA is diffused out from crystalline solid phase, so the deep oxidation reaction will at high temperature make the TA in the slurry all dissolve or be partly dissolved, 4-CBA could oxidation generate TA after entering liquid phase.
The deep oxidation reaction is not fierce, and is not high to the mass-and heat-transfer requirement yet, the reactor that the conventional depth oxidation reaction adopts band to stir, and purpose is to avoid the suspended nitride deposition, and mixes dispersion air, increase reactor gas holdup.
In the embodiment shown in Figure 2, PX, circulation HAC and catalyst by proportion are sent into the oxidation reactor of bubble tower structure, reactor bottom passes into technique compressed air, under 186~188 ℃ of temperature, pressure~1.25MpaA condition, carry out oxidation reaction, generate TA and intermediate product, reaction paste enters discharge tank from the output of oxidation reactor bottom, the discharge tank bottom passes into deep oxidation tail gas and fresh air, bubbling is mixed slurry, Solid Suspension is not deposited, and make intermediate oxidation product (PT acid, 4-CBA etc.) continue oxidation.(oxygen content~3.5%vol) enters oxidation reactor to discharge tank top tail gas, discharge tank bottom slurry (contains PT acid~500ppm, 4-CBA~2500ppm), through mashing pump boost and heater heating after, penetration depth oxidation reactor middle and upper part, tail gas and part technique compressed air mix after the treatment and purification, through supercharging (~4.8MpaG, 4.5-4.8MPaG for example) sends into deep oxidization reactor bottom bubbling after and mix slurry, the deep oxidation reaction is 220~250 ℃ of temperature, carry out under pressure 1.5~4.6MPaG condition, make PT acid, the further oxidation of 4-CBA generates TA.Deep oxidation tail gas is discharged in the deep oxidization reactor top under pressure control, this tail gas is mixed gas as the oxidation reaction discharge tank and used, slurry (PT acid content~50ppm, for example 20-50ppm that the deep oxidation reaction is finished; 4-CBA~150ppm, for example 100-180ppm), under liquid level control, enter crystal system.
The effect of described discharge tank, the one, anti-oxidation discharging is short-circuited, and the 2nd, rear oxidation.Do not deposit in order to guarantee the gas holdup that material in the discharge tank is enough and fully to mix slurry, discharge tank design draw ratio 6~10, the suitable oxidation reactor 10~15% of volume, deep oxidation tail gas and/or compressed air input and output material bottom of the barrel can arrange suitable air intake structure, to form better bubbling effect, deep oxidation tail gas and compressed air can enter respectively discharge tank, also can enter together with the form of mist discharge tank or mix in intake process by accessing same import.
The deep oxidization reactor charging aperture is located at the middle and upper part, and special construction is adopted in the bottom air inlet, reaches the suspended nitride effect of mixing.Deep oxidization reactor design draw ratio is 5~8, and volume is approximately 70~80% of oxidation reactor, by the liquid level control and regulation deep oxidation time.
As shown in Figure 3, the deep oxidization reactor preferred design becomes the reactor of two series connection, second deep oxidization reactor (deep oxidization reactor II) controlled pressure will be lower than the first deep oxidization reactor (deep oxidization reactor I), so that discharge and step-down, How to choose is selected by requirement of engineering.
Enter the oxidation reaction slurry of discharge tank, make it mix suspension with deep oxidation tail gas, and continue oxidation, make a large amount of PT acid generate 4-CBA, part 4-CBA further generates TA.The tail gas that discharge tank top is compiled enters the oxidation reaction liquid phase by " ∩ " type (inverted U-shaped) curved pipe, finally enters the oxidized tail gas system.Discharge tank bottom slurry is extracted out with booster pump, with the sendout of liquid level control booster pump.Before the slurry penetration depth oxidation reactor I, with 60~80bar Steam Heating, its degree of heat is controlled by the deep oxidation reaction temperature.Pass into the pressurization gas that is mixed by tail gas after purifying and compressed air in deep oxidization reactor I bottom, make slurry suspension in the reactor, and make PT acid and 4-CBA oxidation generation TA in the liquid phase.230~250 ℃ of deep oxidization reactor I operating temperatures, pressure 4.0~4.6MPaG, preferred 4.5MPaG~4.6MPaG.
Deep oxidization reactor I slurry enters deep oxidization reactor II middle and upper part under liquid level control, deep oxidization reactor I top tail gas passes into deep oxidization reactor II bottom under pressure control, 220~230 ℃ of deep oxidization reactor II operating temperatures, pressure 1.5~2.0MPaG.The deep oxidization reactor II is with pressure conditioned reaction temperature.The effect of deep oxidization reactor II is:
(1) the reaction trend is finished
(2) regulate product cut size
Slurry behind the deep oxidation enters crystal system under liquid level control.
Change the regulation depth degree of oxidation according to end product quality, its control device is to adjust deep oxidation temperature and the time of staying, the adjustment of deep oxidation temperature can control to realize that by pressure the control of reaction time can be finished by regulation depth oxidation reactor height of liquid level.
The utility model KPTA deep oxidation technique is the medium temperature and medium pressure technology, the device structure that not only adopts differs from the world other manufacturers, in the control of technological parameter, both be different from the deep oxidation technique of high temperature, high pressure TA solid CL, also differed greatly with low-temp low-pressure diffusion deep oxidation method.
The utility model is by changing the structure of each reactor, substitute mechanical agitation with gas sparging, and changed the condition of deep oxidation reaction, change into medium temperature and medium pressure by the high-temperature and high-pressure conditions under the prior art, material requirements and the technological requirement of equipment have been reduced, not only investment descends (fall about 50%) thus, and saves the agitator power consumption.Concerning megaton PTA device, compare with traditional handicraft, can reduce investment outlay~4,000 ten thousand yuan, electric consumption can be saved~1000kWh/h.