The energy-optimised technology of utilizing of acroleic acid device reaction unit
Technical field
The present invention relates to a kind of organic chemicals vinylformic acid production technique.
Background technology
Propylene second oxidation method is produced vinylformic acid, is a thermopositive reaction.Reaction is finished in two steps.The first step propylene oxidation generates propenal, and second step further was oxidized to vinylformic acid with propenal.Its reaction formula is as follows:
CH
2=CH-CH
3+O
2→CH
2=CH-CHO+H
2O+334.88kJ
CH
2=CH-CHO+1/2O
2→CH
2=CHCOOH+251.16kJ
From above-mentioned reaction formula as can be seen, react by propylene and airborne oxygen, the heat that the vinylformic acid of every generation 1mol will be emitted 586.04kJ, these heats are removed by molten heat transfer salt, by the saturation steam of water cooler generation certain pressure, send into steam pipe system.Simultaneously, the waste gas that reaction member produces need enter the catalytic burning system and carry out the catalytic burning processing, can discharge a large amount of heats, can not utilize, and causes energy dissipation, the expense when increasing the waste gas cooling again.Reaction member needs superheated vapour to drive with the turbine of air compressor, need mend not superheated vapour.Existing plant energy consumption height, the wasting of resources, contaminate environment, thereby the overall efficiency of reduction device.
Summary of the invention
The objective of the invention is to overcome the deficiency of prior art, a kind of energy-optimised technology of utilizing of acroleic acid device reaction unit is provided.
In the vinylformic acid production process, in the first reactor R-1, propylene is oxidized to propenal selectively, and the minor amounts of acrolein deep oxidation becomes vinylformic acid.The heat that reaction generates is shifted out by the inorganic salt thermal barrier (hereinafter to be referred as HTS) that is circulated in the reactor shell side, and this heat produces 1.5MPaG steam by E-3 and E-4 (R-1 the one HTS water cooler and R-1 the 2nd HTS water cooler) and enters high pressure steam jar D-4 afterwards.
In the second reactor R-2, acrolein oxidation becomes vinylformic acid, and the heat that reaction generates is shifted out by the HTS that is circulated in the reactor shell side, and this heat produces 1.5MPaG steam by E-5 (the HTS water cooler of R-2) and enters flash tank D-4 afterwards.
In flash tank D-4, produce the saturation steam of constant voltage.
The solution of the present invention is: the saturation steam that reaction member high pressure steam jar D-4 is produced is sent into catalytic burning unit superheater E-7 and is carried out overheatedly, and its temperature of superheat can be required by the turbine of compressor decide.
The heat that reactor produces can generate the steam of 1.5-2.0MPaG in E-3, E-4 and E-5.The steam that produces is sent into the further flash distillation of flash tank D-4, can generate the saturation steam of 1.5-2.0MPaG after the pressurize.
A kind of energy-optimised technology of utilizing of acroleic acid device reaction unit, the reaction heat that the first reactor R-1 generates is shifted out by the thermal barrier that is circulated in the reactor shell side, through water cooler E-3, E-4, with the water coolant heating and deliver to flash tank D-4; The reaction heat that the second reactor R-2 generates, shift out by the thermal barrier that is circulated in the reactor shell side, through water cooler E-5, with water coolant heating and deliver to flash tank D-4, flash tank D-4 flash distillation gets steam 1.5MPa~2.0MPa, it is characterized in that, steam after this flash distillation is sent into superheater E-7, it is overheated to carry out, its pressure 1.5~2.0MPa, 300~320 ℃ of overheated back vapor temperatures, the steam after overheated is used as the power that compressor KT-1 drives turbine, and the exhaust temperature of incinerator R-4 is reduced to 400~450 ℃ from 500~550 ℃.Superheater E-7 is located at after knockout tower C-1 cat head emits tail gas burning furnace R-4, burns heat with its tail gas and is used for steam superheating.
Remarkable benefit of the present invention, the reactor outlet temperature of catalytic burning system can reach about 550 ℃, produce superheated vapour through waste heat boiler after, 1, the temperature of waste gas can drop to about 450 ℃. reduced the load of exhaust gas cooler and the exhaust temperature of cleaning of off-gas.2, the superheated vapour that produces through waste heat boiler can reduce the energy consumption of device continuously for the air compressor turbine use of reactive system.
Adopt the present invention also can play the effect of flexible operating at the driving initial stage of device, the driving initial stage can be introduced external source of the gas, when the device load reaches 100% the unitary superheated vapour of catalytic burning is switched to compressor turbine.
If there is not enough steam to use outside the device battery limit (BL), can before driving, reactive system start the catalytic burning system for driving.In the stove that goes into operation of catalytic burning system, add fuel gas, the temperature of control catalytic burning reactor, liberated heat is produced 1.5-2.0MPaG by waste heat boiler saturation steam uses for driving initial stage compressor turbine.When the device load reaches 70%, close fuel gas charging valve gradually.
Description of drawings
Fig. 1 is the concise and to the point process flow sheet of the present invention
Embodiment
Below in conjunction with specific examples the utility model is made detailed description further.
Certain produces 80000 tons of acroleic acid devices per year, and the reactive system liberated heat is 29943kW/h, and by E-3, it is 25.787t/h that E-4, E-105 produce the 1.5MPaG saturation steam respectively, 2.973t/h, 14.192t/h.The catalytic burning system will produce the heat of 29943kW/h, and it is 8.69t/h that E-6 produces the 1.5MPaG saturation steam.KT-1 consumes 1.5MPaG superheated vapour 45t/h.Produce the 0.3MPaG steam of 44.37t/h.After the invention process, can utilize the heat of the used heat 29943kW/h of catalytic burning system, compressor turbine need not external steam, needn't establish steam boiler, steam superheating apparatus in addition, reduces initial cost and working cost.
When the initial stage of driving, the turbine of compressor drives can dual mode.First kind of mode, the fuel gas of the certain calorific value of feeding in the stove that goes into operation of catalytic burning system when producing 1.5MPaG constant voltage saturation steam 8.69t/h, is introduced KT-1 with this steam earlier, when load reaches 70%, the inlet valve of fuel shutoff gas.At this moment, the steam that reactor is produced switches in the overheated steaming device of catalytic burning.The superheated vapour that produces is fed among the KT-1.KT-1 produces the 0.3MPaG saturation steam simultaneously.
The second way is: the driving initial stage is introduced the 1.5MPaG saturation steam from outside ductwork, uses for KT-1.When load reached 70%, it is stable that reactor produces steam, and the high pressure steam that D-4 is produced switches to the superheated vapour that produces in the vapor superheater under this pressure, uses for KT-1.
The invention has the advantages that the cat head of knockout tower C-1 is emitted tail gas after incinerator R-4 burns, If it is overheated that the steam that superheater E-7 comes out to D-4 carries out, KT-1 drives for this device air compressor The usefulness of turbine, tail gas burns, and reduces the pollution to atmosphere, and its tail gas acts as a fuel and recycles, Heat is used for heating steam, and this superheated steam is sent into the turbine of KT-1, thereby needn't build boiler for this reason again, Set up filter apparatus and can reduce construction costs, reduce the operating cost of device, its economic and society's effect Yidu is significant.