• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:

    公开号:SU980611A3
    申请号:SU782640503
    申请日:1978-07-20
    公开日:1982-12-07
    发明作者:Фаттингер Фолкэр
    申请人:Циба-Гейги Аг (Фирма)；
    IPC主号:
    专利说明:

    (5) METHOD FOR MANAGING THE PRODUCTION OF SULFUR
    ACID NITROZOUS METHOD FROM THE CONTAINING
    SULFUR SULFUR FLOW
    one
    The invention relates to managing the production of sulfuric acid by the nitro method and can be used in the chemical industry in automating the production of sulfuric acid by the nitrous method from a sulfur dioxide containing effluent gas stream.
    There is a known method for controlling the production of sulfuric acid by the nitrous method, based on controlling the density of the acid leaving the denitration zone and changing the feed of diluted acid or water into it, 1.
    The disadvantage of this method is the large loss of nitrogen oxides with waste gases.
    The purpose of the invention is to reduce the loss of nitrogen oxides with waste gases.
    This goal is achieved in that according to the method, the flow of the product containing nitrogen and oxygen compounds to the recirculation circuit of dilute acid 9 is further controlled depending on the content of nitrogen oxides in the gas stream of the absorption zone.
    The content of nitrogen oxides is determined at the inlet or at the outlet or inside the absorption zone.
    In addition, nitric acid or nitrogen oxides are used as a product containing nitrogen and oxygen compounds.
    Installations for the production of sulfuric acid by the nitrous method consist of several towers filled with nozzle, connected in series,
    , 5 through which the acid recycles various concentrations. Significant losses of nitrogen oxides occur, KOI- and exhaust gases contain an excess of N0 or an excess of N0. Correct
    20 ratio of N0. is a prerequisite for optimal absorption of nitrogen oxides. N0 is a colorless (invisible) gas, therefore improper regulation of the system sulfuric acid – nitrogen oxides can in a short time result in the loss of large amounts of nitrogen oxides with the exhaust gases escaping into the atmosphere without a visible yellow plume. In the production of sulfuric acid by the nitrous method, it is advantageous to operate the installation in such a way that tanga gases do not have a slight, but distinctly yellow shade. Increasing the content below. Lowering the N0 content in the waste gases of the sulfuric acid – nitrogen oxides system can be achieved by increasing the addition of nitric acid, reducing cooling in production towers and / or increasing the addition of water. In production towers Adjusting some conditions in one packed tower Systems always affect the conditions in other packed towers, so it is quite difficult to keep the whole system in balance. To service the known sulfuric acid-nitrogen oxides systems, skilled and qualified personnel are required who can operate the plant with minor losses of nitrogen oxides. Thus, the loss of nitrogen oxides in the system should be compensated by the addition of nitric acid or concentrated nitrous gases, for example, gases formed during catalytic oxidation of ammonia. In the known plants for the production of sulfuric acid by the nitrous method, the addition of nitric acid or the addition of concentrated oxides containing nitrogen oxides is carried out at the head of the denitration tower or at the beginning of the flow of the production tower, which is irrigated with an acid concentration of more than 70% by weight. % H, SOx In the known systems, sulfuric acid — nitrogen oxides, the need to add nitric acid or a gas with a high content of nitrogen oxides is determined, in particular, by the content of nitrosis in the acid, which flows from the absorption zone to the sediment of this zone, as in this zone The acid content of nitrosis is highest in comparison with all acids in the system. In the invention, all towers of the system irrigated with sulfuric acid with a concentration of more than 60% by weight, and the evolved gases containing more gas-nitrogen compounds and oxygen than the gases entering the tower are in the denitration zone. In the known plants for the production of sulfuric acid by the nitrous method, the addition of nitric acid or other substances containing nitrogen oxides is carried out anywhere in the denitration zone, and the color control of the exhaust gases of the system, i.e. regulation of the NO: NO ratio, 2. These gases are usually accomplished by adding more or less water to the acids recirculating through the denitration zone and through the absorption zone of nitrogen oxides. The operation of the installation requires constant monitoring, which requires numerous measurements of the density and determination of the nitrosis content in the recycled acid. Automatic control of known systems is hardly feasible. . In addition, a disadvantage of the known sulfuric acid-nitrogen oxides systems is the very slow response to adjusting the NO.NO.- ratio in gases. For example, if a decrease in the content 502 in the incoming gas leads to the formation of a yellow strip in the gases leaving the system, it is necessary to adjust the operation of the installation in the manner described, which has its effect and causes the disappearance of the yellow color of the exhaust gases only after a few hours. The proposed method solves the problem of adjusting the composition of the waste gases of sulfuric acid production by the nitrous method within a few minutes and provides automation of the entire system, improves the speed way of regulating the NO: N02 ratio in the gases leaving the system so that they exit without (or practically without) a yellow plume due to the content of N02 in them from the chimney to remove waste gases and at the same time without excessive loss of (colorless) N0 in the system. In addition, the eGssi gas flow is improved from a system in which the content of nitrogen oxides is below the upper, prescribed by law limit (for example, 400 ppm). Regulation of the process includes the following steps: measuring the content of N0 in the gas stream in the absorption zone or below (downstream) of the zone, absorption or at the same time in the absorption zone and below it, and introducing the compound of nitrogen and oxygen into diluted recycled acid of at least one of the two sectors of the treatment zone, S02 in those cases when, at the point (or points) of N0, the specific limit value of the N0 content or the steepness of the increase in the unit time of the N0 content in the gas stream are exceeded in an amount sufficient for Neny exceeding this without measurable Neny acid concentration in the area and sorption. Specific limit values for holding N0 or the steepness of the increase depend on the particular design of this installation, in particular, on the size of the various towers. In the production of sulfuric acid by the nitrous method, in particular by Petersen's intensified tower method, it is necessary to determine the optimal operating conditions of the process for each particular installation and then adjust the instrumentation used in the proposed method so that they achieve the optimum limit value. or optimum steepness increase. The optimal NO: NOo ratio in the absorption zone or in the exhaust gases of the absorption zone can reach within several jets and the whole system can be automated if, depending on the N0 content in the gases leaving the absorption zone, nitric acid or others liquid or gaseous substances containing a compound of nitrogen and oxygen are fed to the recirculating dilute acidic one or to treatment zone 50, which is irrigated with dilute acid. Diluted acid loses added nitric acid or other compounds containing nitric oxide relatively quickly. During the consumption of the nitrogen contained in the dilute acid, a vigorous reaction takes place, and the treatment 50 is significantly accelerated. Thus, the invention provides compensation in response to an increased N0 content due to insufficient total NOy in the system. An increase in the N0 content in the system indicates. 1 "The activity of a dilute acid recirculating in the relevant sector or in both sectors of the SOv treatment area is reduced. By adding small amounts of nitric acid or a similar compound of nitrogen and oxygen, the activity of the dilute acid in treatment zone 50 is stimulated enough to effect the conversion of 50 -SO-s, in the treatment zone of SO and, even in the case of a deficiency of nitrogen oxides, in the overall balance of the systems. This makes it possible to maintain in the system the minimum possible N0 content, i.e. the system does not require an excess of N0 .. Changes occurring in the system, especially those caused by variations in the content of SO2 in the incoming gas, are corrected for a few seconds, and the stimulating effect of each injection of small amounts lasts approximately 10-15 minutes. Consequently, the measures described for regulating the content of nitrogen oxides are aimed, first of all, not at increasing the NOy content in the system due to the general lack of N0) 1, but at stimulating the activity of the dilute acid recycle in the treatment zone 50 every time it becomes not enough. Nitric acid or nitrogen oxides are added to the SO treatment zone in the liquid phase of the dilute acid. - Preferably, a liquid that is or contains a compound of nitrogen and oxygen (e.g., nitric acid), or mixed with dilute acid, is introduced into the nozzle of the treatment zone tower 50 so that the added dilute acid liquid mixes in the nozzles towers of this zone. Compounds of nitrogen and oxygen are such compounds that are used in the nitrous method of producing sulfuric acid, i.e. 0, N0, .0b nitrosis or nitric acid, and also (optionally) verdice chamber crystals. In the nitrous method of nitrous acid, it is oxidized oxidatively to nitric oxide, or nitrous anhydride is released, or it forms nitrose with sulfuric acid. Gaseous substances that contain nitrogen bound to oxygen are gases that contain NO or NO, or. liquid substances are, in particular, nitric acid itself or nitrosa. 5
    The amount of a substance containing a compound of nitrogen and oxygen increases in proportion to the increase in the content of N0 in the gas stream in the absorption zone or after it.
    However, in installations with a simple scheme, the rate of addition of a substance containing a compound of nitrogen and oxygen can be kept constant as long as the content of ts N0 in the gas stream is lower (along the gas flow) of the absorption zone and is higher than the mentioned content of N0.
    The amount of nitrogen and oxygen compounds added at each stage of regulation in treatment area S02 (pretreatment sector or main sector) is very small compared to the total amount of nitrosis recirculating in this topic. Assuming that the system continuously recycles about 100 tons of acids with a content of about 3% nitrosis in the acid phase and in the gas phase, this means that about 3 T of nitrosis is recycled in the system. For a corrective action in response to an increased content of N0, measured at the indicated points, it is necessary to add to the diluted acid that is recirculated in the treatment area SO., From 100 to. 1000 ml of nitric acid or a similar compound of nitrogen and oxygen. Such negligible amounts of a compound of nitrogen and oxygen cause the desired effect for less than 10 minutes, and are not the usual compensation for the loss of N0) in the system as a whole. This will require the addition of a significantly larger amount of nitrose-containing acid or nitric acid to compensate for NOx losses in the system, and in previously known intensified processes, the addition is preferably carried out in the JQ denitration zone.
    When working in another way, the amount of a substance that contains a compound of nitrogen and oxygen increases at such a rate that the limiting value of the steepness of the increase per unit time of the N0 content in the gas stream in the absorption zone or below it (along the gas flow) is exceeded.
    Nitric acid is preferably used as the compound of nitrogen and oxygen.
    In addition, the compound of nitrogen and oxygen consists preferably of nitrogen oxides, formed by burning ammonia.
    A liquid substance containing nitrogen combined with oxygen can be obtained, in particular, by absorption of nitrogen oxides with sulfuric acid.
    Addition of the above-mentioned compound of nitrogen and acid; hydrogen or a substance containing eroj is preferably stopped, then the content of N0 in the gas stream below (along the gas) of the absorption zone falls below a constant value that is below the limit of N0 or the addition of a substance N o in the gas stream below (along the gas flow) the absorption zone falls below a predetermined limit value of the increase slope per unit time.
    For efficient operation, it is preferable to measure the NOnB concentration of the gas in the bottom of the gas (along the gasT of the absorption zone and stop adding this substance to the recirculation diluted acid in the treatment zone when a certain content of N0 2 is exceeded or when the limit of increasing the N0 content in the gas flow is exceeded N0. In this connection, it is advisable to increase the amount of nitrose-containing acid flowing from the absorption zone, and, accordingly, introduce acid into this zone with a lower content nitrose or completely free of nitrosis from the denitration zone when the second, upper limit of N0 in the gas stream is below the gas withdrawal zone of the absorption, or when the second upper limit of the steepness of the increase in the NO content is exceeded, in the gas stream below (downstream .a) absorption zones.
    At least part of the substance
    entered into the treatment zone 50, may consist of a nitrous acid containing sulfur acid taken from the absorption zone, in this case the content of nitrogen and oxygen compounds in the sulfuric acid containing nitrose. selected from the absorption zone and entering the treatment zone 50 can be increased by adding nitric acid. In a preferred embodiment of the method, a pre-treatment zone is provided above (along the gas) in the denitration zone, through which the diluted acid is recycled separately and through which the gas stream passes before it enters the denitration zone. A portion of the total amount of a compound containing a compound of nitrogen and oxygen, or the compound itself, is introduced into the pretreatment zone. The amount of this substance can be diverted from sulfuric acid containing nitrose, which flows from the absorption zone to the treatment zone 50. At least m part of the amount of nitrogen and oxygen compounds to be introduced into the pretreatment zone may consist of gaseous nitrogen oxides, which receive by oxidizing ammonia and introducing I into the gas stream before it enters the pretreatment zone. The content of the compound of nitrogen and oxygen in the nitrose-containing selected and absorption zone sulfuric acid, which partially introduces, into the main sector of the treatment zone and partially into the sector of the last zone, which forms the pre-treatment zone, can also be increased by adding nitric acid. In addition, the density of the acid leaving the denitration zone can be kept constant by adding dilute acid or water, while the density of the dilute acid recirculating through the main sector of the SO treatment zone can be kept constant by adding acid from the pretreatment zone or water. The invention provides an installation for separating N0 from a finished stream containing SO at least periodically, at concentrations that are unacceptably high for emission into the atmosphere, with the concomitant production of sulfuric acid in a nitrous manner, and the operation of this installation is regulated depending on the content of N0 or N0 and N0 and / or NOrNQj ratios in the exhaust gases of the system. the plant includes in series a denitration zone, a SO treatment zone. and a nitrogen oxides absorption zone, each zone including at least one device for carrying out the reaction between gas and liquid, which is equipped with a sump for collecting liquid exiting from the bottom of the corresponding device, a gas flow line which subsequently enters into which -or part, preferably the lower, denitration zone and goes from any part, preferably the top, of this zone to the treatment zone 50, from where it goes to the absorption zone of nitrogen oxides and leaves from any part, preferably the top the absorption zone to the atmosphere) the diluted acid recirculation line through treatment zone 50-, the acid recirculation line from the first sedimentation tank (along the gases) of the nitrogen oxide absorption zone to the upper part of the denitration zone and the settling tank of this zone to any part, preferably the reaction device, the absorption zone of nitrogen oxides, which is provided for in the proposed installation, the compound and nitrogen supply line, nitrogen and oxygen to the liquid or gas phase, which is connected to the recirculation line of the dilute acid through the SOx treatment zone, measuring device for determining the N0 content in the gas stream, and this device is connected to the absorption zone or with the line, the gas stream below (along the gas flow) the absorption zone or simultaneously with the absorption zone and the line below (along the gas flow) absorption and an adjusting device for adding a compound of nitrogen and oxygen depending on the content of N0, measured with a measuring device. An improved version of the proposed installation provides a device for measuring the N0 content of the gas stream: the device is connected to the gas flow line below (along the gas flow) the absorption zone and the rectifying device includes an improved adjustment device that turns off or reduces the flow of nitrogen and oxygen depending on the N0 content the gas flow measured at 11 by the aid of a device for measuring the content of NOjj. The installation of the supply line of the compound of nitrogen and oxygen in the form of sulfuric acid containing nitrose can preferably be connected to the settling tank of the reaction device of the nitrogen oxides absorption zone. This supply line can be equipped with means for introducing nitric acid into it. The proposed installation may include in the pretreatment zone above (along the gas flow) denitration zones having a reaction device and a settling tank, while the Pelvic Flux line passes first into the pretreatment zone, preferably to the lower part of it and from another part of it in some part, preferably in the lower denitration zone, where a separate line can be provided for recirculation of dilute acid through it, preferably passing through the pre-treatment zone. top-down processing, as well as an equalization line between the detachments of the preliminary treatment zone and the denitration zone, and the diversion from the mentioned supply line to the upper part of the pre-treatment zone. FIG. 1-5 are examples of installation performance that implements the proposed method. The plant for the production of sulfuric acid by the nitrous method (Fig. 1) includes the usual contact towers for carrying out the reaction between the gas and the liquid, filled with a packing. Downstream of the gas flow of the denitration tower 1, there is an SO treatment area. with the first tower 2 and the second tower 3 below which there are nozzles and 5, which are in the same head and form an absorber / 5 and nitrogen oxides zone. The exhaust gas containing SO. That is to be processed enters through the inlet pipe 6 to the lower part of the denitracy tower 1 and via pipeline 7 goes to the head part of tower 1 to the head part of the tower 2 of the treatment zone 50, through the gas pipeline 8 from the lower part the nozzle of the tower 2 is in the lower part of the nozzle of the tower 3, from where through the pipeline 9 through the nozzle of the if to the tank 5, from the head of which 112 through the pipeline 10 by means of the fan 11 is released into the atmosphere. As in the known installation, the diluted acid is recirculated through the dilute acid supply line 12 by means of a pump 13 through the heat exchanger 14 to the head of the nozzle of the tower 2 and is collected in its lower part in a sump 15, from which the diluted acid is pumped through the heat pump 1b through the heat exchanger 18 to the head of the packing of the tower 3. The recirculation circuit of the dilute acid through the treatment zone 50 is closed by pumping the dilute acid from the settler 19 of the tower 3 through line 20. Preferably, this Sulfuric acid is used at a concentration of approximately b5 weight in the recycling of the dilute acid. The density of the dilute acid recirculating in the treatment area SQ is measured using a device 21 for measuring the density of the acid output from the septic tank 19. The density can be adjusted by known methods by adding either water, or acid (corresponding valves and piping not shown). Sulfuric acid containing nitrose is pumped out by pump 22 from the sump 23 of the common tower of the nitrogen oxides absorption zone (the sump is under the nozzle) via pipe 2k to heat exchanger 25, where it is heated and then through pipe 2b of acid supply goes to the head of denitration tower 1 to irrigate in the tower 1 nozzles. After passing through the nozzle of tower 1, the train is radiated. after denitration, the acid is collected in the sump 27 of tower 1 and is pumped by pump 28 through conduit 29 to heat exchanger 30 and from there via conduit 31 to the head of the upper nozzle 5 in the OXID-nitrogen absorption zone tower. From nozzle 5, the acid flows downwards into nozzle k, and the gas to be processed passes from nozzle k to nozzle 5. In this case, no-L is required. , gas semka between both nozzles. After denitration, sulfuric acid with a concentration of 70-80 wt.% Can be withdrawn from conduit 31 through conduit 32 with valve 33 located therein to acid collector 3 and discharged from the system through an effluent conduit.
    Thus, the denitration stage is carried out in a known manner in the nozzle of the tower 1. Processing stage 50 is carried out in the nozzles of the towers 2 and 3 :, and the stage of absorption of nitrogen oxides in the nozzles L and 5 of the common tower. In the treatment area SO of tower 2 and 3, sulfuric acid with a concentration of less than 70 wt.% H SO / (diluted acid) is used. In the denitration zone of tower 1 and in the zone of absorption of nitrogen oxides, an acid concentration of 70–85 wt. HSO (absorption acid). The preferred concentration of absorption acid is 72-80 weight L.
    As in the known plants for the production of sulfuric acid by the nitrotic method, nitrogen oxides are liberated in the free state from the acidic 20 TU introduced into the process according to the invention in the denitration zone and pass through the gas line to the absorption zone, where the gaseous oxides nitrogen is absorbed by sulfuric acid. This process is as follows. The nitrose-free absorber of onna acid, going from the nozzle of the tower 1 to the sump 27, is cooled in the heat exchanger 30 and pump 28 via line 31 to the nozzle 5, from where it enters the nozzle 4 and from it to the sump 23, where from the pipeline 24 is pumped 22 into heat exchanger 25 and through pipe 26 returns to the nozzle of tower 1, in which the nitrogen oxides absorbed by the acid in nozzles 4 and 5 are again released into the gas stream. Further, the acid is additionally pumped by pumps in a known manner from the settling basins of each tower to the head It is the same tower to intensify the mass transfer between the gas and acid (srotvetstvuyuschie device not shown). In the installation (Fig. Provided collector 35 containing nitric acid or sulfuric acid with a high concentration of nitrosis and / or nitric acid. Nitric acid flows through the pipeline Zb to collector 35. Pipe 37 with valve 38 connected to the sump 23 of the oxide absorption zone nitrogen leads to collector 35. Sulfuric acid containing nitrose can be supplied via line 37 to collector 35, which is connected
    pipe 39, equipped with a pump kQ and valve 41, with the head of the first tower 2 treatment areas SOj.
    The analyzer 2 is connected to the pipeline 10 and continuously measures the content of N0 in the gases passing through the IT pipeline from the nozzle 5 of the tower of the absorption zone. If the N0 content is less than the allowable value, or if the increase rate of the N0 content exceeds a predetermined speed, the pump 40 is turned on by a signal from the analyzer k2 and sulfuric acid with a high content of nitric acid enters through the valve t into the nozzle of the tower 2.
    If the analyzer k2 indicates that the content of N0 in the gases leaving the absorption zone is lower than the allowable value, or if the rate of decrease of the nitrogen oxide content in these gases exceeds the minimum allowable rate of decrease, pump 40 is turned off. Instead of turning the pump 40 on or off, you can also adjust the flow of sulfuric acid with a high content of nitric acid, by increasing or decreasing its flow. The delay of the response of the control system to the signal from the analyzer is several minutes ..: In the installation (Fig. 1) analyzer 42 is shown installed in the head of the nozzle 5 of the absorption part of the tower. The content of nitrogen oxide at the inlet of the gases in the nozzle 4 of the absorption tower or between the nozzles 4 and 5 of the absorption zone can be measured. The content of nitric oxide at these points is correspondingly higher than at the outlet from the absorption zone. However, it is possible to use the measurement inside the nozzle of the absorption zone as an adjustable parameter. This causes a decrease in the response delay to the signal. It is possible (in some cases appropriate) to measure the N0 content simultaneously at various points in the absorption zone of nitrogen oxides. In addition, it is advisable to add a compound of nitrogen and oxygen, a liquid or gaseous substance containing this compound, as close as possible to the beginning of the flow in the system. In this case, it is possible to have 159 a significant effect on the content of N0 in the waste gases of the plant, even with the introduction of relatively small amounts of a compound of nitrogen and oxygen. Thus, the invention allows to automate the production of sulfuric acid and the nitrous method. In the installation (FIG. 2), moist gases containing SOg are brought into contact with dilute acid in the pretreatment tower above (along the gas flow) denitration zone, with some of the water vapor being extracted from these gases in tower nozzle 3. Diluted acid, The downstream of the tower nozzle. 3 to the sump kk of the same tower, is pumped by pump kS through line 6 to heat exchanger 7, where the acid is heated, and then through line A8 to the head part of tower L9, the nozzle of which forms an acid dewatering zone. Additional heating of the acid in the heat exchanger 7 intensifies acid dehydration in the nozzle of the tower 49. The tower 43 of the pre-treatment zone forms the first sector of the treatment zone 50. The recirculation circuit of the dilute acid through the pre-treatment zone through the k8 pipeline is separated from the recirculation circuit of the dilute acid in the main treatment zone 50 It closes by supplying diluted acid via pipeline 8 -to the head of tower 9 to irrigate the nozzle in this tower. From where the acid through this nozzle and gate 50 in the lower part of tower 9 flows into the nozzle of tower 3. The water absorbed by the acid during its recirculation through the tower nozzle 43 is transferred in this way through conduit 48 directly to the end of the entire system, t. e. into the nozzle of tower 49, where it is released as water vapor into the exhaust gases of the system supplied to tower 49 through conduit 51. Passing through the pretreatment zone in tower 43, the diluted acid is preheated. The additional heating in acids in the heat exchanger 47 intensifies the release of water in the nozzle of the tower 49. The evaporated water leaves the system in the form of steam together with the SOj containing no. exhaust gas via conduit 52. 16. Due to the dehydration stage, the gas stream is dewatered in the pretreatment zone, and the rest of the system receives less (or not at all) water vapor with the gas stream, which allows constant maintenance of the required acid concentration ( for example, 75 wt.% H2SO4.) in the nozzle of the denitration tower 1, as well as in the nozzles 4 and 5 of the absorption zone. By adjusting the supply of fuel to the heat exchanger 47, it is possible to regulate the amount of water released from the acid recirculating through the nozzles of the towers 49 and 43, thereby maintaining the desired acid concentration in this recirculation loop. Nitric acid (or sulfuric acid containing nitrose or nitric acid) is supplied from collector 35 by pump 40 through conduit 39 to valve 53 and further along conduit 54 to the head of the nozzle in tower 43, which is irrigated as soon as analyzer 42 opens valve 53 and turns on the pump 40. Tower 43 (Fig. 2), irrigated with dilute acid and located above the denitration zone along the gas stream, serves to regulate the entire system. The packed tower 43 (or the corresponding reaction device of another type for carrying out the reaction between a liquid and a gas), respectively, receives the total amount of a nitrogen and oxygen compound, a liquid or gaseous substance containing such a compound. The lower part of the nozzle of the tower 49 is connected by a pipeline iil to the fan 11, and dry exhaust gases from the nozzle of the tower 5 of the absorption zone enter through this pipeline. Exhaust gases extract water from the acid in the nozzle of the tower 49 and, together with the water heater, they leave through the pipeline 52 to the atmosphere. Until now, the NC: NOrt ratio in the waste gases of the plant or in the absorption zone of the sulfuric acid production plants was adjusted by the nitrous method by varying the concentration of acids in certain recirculation circuits of the plant. This was accomplished by adding water or dilute acid to the more concentrated acid in at least one of the recirculation circuits. Such a change in acid concentration may not be used in the regulation of the system according to the invention. It is sufficient to maintain the constant density of the acids at the exit of the denitration zone and in the recirculation circuit through the treatment zone 50-2. The density of the acids can be kept constant with the help of known devices for automatic density control. An instrument 35 for measuring the density (Fig. 2) is provided on the drain pipe 29 from the sump 27. This measuring device acts on the valve, and the required amount of diluted acid is supplied by pump 22 through line 2b to the nozzle of the denitration tower 1. Device 55 for measuring the density regulates the addition of diluted acid in such a way that at the exit from the denitration zone, i.e. At the outlet of the nozzle of the denitration tower 1, a constant acid concentration is maintained. . Equalizing conduit 5b soaks the sumps A and A5 and thus ensures the leveling of the acid levels in both sumps. In the installation (Fig. 3), in the first sec-30 torus of the SO treatment zone, namely, in the tower of the pretreatment zone, not all of the nitrogen and oxygen compound or the substance containing such a compound is introduced, but only a part of it, while the rest are introduced, as in the installation shown in FIG. 1, into the head of the tower 2, i.e. in the main sector of the treatment zone 50, can be adjusted by appropriate adjustment of the valves 41 and 53. The larger the gas-liquid contact surface, in the reaction towers of the SO- treatment zone, the faster the chemical reactions take place at the SO, processing stage. With the simultaneous introduction of a compound of nitrogen and oxygen into the first sector of the SO treatment zone, and into the main sector of the treatment zone 30, i.e. In the nozzles of the towers 3 and 2, a much larger surface is irrigated, corresponding to the sum of the volumes of the nozzles of 2 and 2, and accordingly an increase in the speed of the whole process of treatment SOj is achieved. In the preferred embodiment of the r.b. (Fig. 3), besides the measurement described for the content of N0, the content of N0, j in gases is measured. The measurement is performed by the analyzer 57 in the absorption zone of the zone or below it {along the gas path. The analyzer 57 is connected to an adjusting device of a known type (not shown), which is superimposed on the action of the analyzer 2 measuring the content in gases N0. As soon as the content of N0 exceeds a predetermined value, the addition of substances containing the compound of nitrogen and hydrogen is stopped or reduced. Moreover, if the content of N0 is too high or the rate of increase of the concentration of N02 is too rapid, the sulfuric acid containing nitrosis is removed from the absorption zone with greater speed appropriate adjustment of the valve 38, and the corresponding - is fed into the absorption zone. amount of sulfuric acid which does not contain or contains a reduced amount of nitrose. Analyzer 57 measures the concentration of N0 in the gases continuously at the outlet of the nozzle 5 as soon as the content of N0 exceeds a predetermined value or the concentration of N0 rises too quickly, the pump stops and the supply of sulfuric acid with a high content of nitric acid from collector 35 to the nozzle of tower 2 is stopped. The pump b8 is also regulated by an analyzer. If the content of N0 rises too quickly at the outlet of. the nozzle 5, the pump 58 is turned on and, in addition, the valve 38 is opened, as a result of which the acid containing nitrose enters the collector 35 and the acid that does not contain nitrosis from the collector 3 through pipe 59 - into the absorption tower nozzle 4, the absorption acid that does not contain nitroses containing nitrose acid from nozzle A to sump 23 and through conduit 37 8 collector 35. If the compound of nitrogen and oxygen is not added in the form of nitric acid, but in the form of gaseous nitrogen oxides, it is less advisable to inject. Gaseous nitrogen oxides directly into the nozzles of towers 2 and 3 of the zone to form SOto. A more rapid and effective action is achieved by first dissolving nitrogen oxides in sulfuric acid, followed by the introduction of the resulting nitrogen oxides. : sulfuric acid in the processing area So.
    1998061
    In the installation (FIG. 4), the nitrogen oxides formed by the BSO for oxidizing ammonia are cooled in heat exchanger 61 and then enter absorption tower 62 from bottom 5 upwards. A part of the nitrogen oxides 62 that are not absorbed in the tower passes through pipeline 63 into the inlet pipeline 6 of the gas to be treated and thus .VV in
    at once enters the main gas flow of the installation. Acid can be by.
    It is given through the pipeline 5 hours through valve 6 to the tower b2, in which it is saturated with nitrogen oxides. Then the acid goes through the settler B5 through the pipe 66 to the pump 67 and through the pipe 68 with yutapan 69 to the nozzle of the tower 2.
    The complete installation (fig. Bj in which all the distinctive features of the presented installations are combined (fig. 1-4) allows, depending on the nature of the gases to be treated and the content of 50 in them, and also depending on what is more ammonia - 25 aka or nitric acid should sweat (rebuild the installation, it is the most economical to treat the waste gas containing SOj.
    An example. The gas flow; 30, containing 50 and other gases in the following gram-molecular amounts per 1 normal m (1 normal m1 m at and 1 at), mol, is taken:
    SOa0,5-0,935
    , 8-3,1
    N 0 i} -6
    , 2 -: - 1.6
    N0 0.01-0.02 Nitrogen Else40
    An adjustable amount of gas is fed into the nozzle of the tower 3 of the installation (FIG. 3). The volume of the nozzle in each of the towers 43 and 49 is 1 m. The volume of nozzles 4. And 5 and in each of the towers 1-3 45 is equal to 2.6 meters. The sum of the volumes of all nozzles is 15 meters respectively. The tower attachment is made of polyethylene. The surface of the nozzle of each tower is 300 m / m. The turnover of JQ acid in the nozzle of the towers 43 and 49 is carried out as shown in Fig. 3 is 2 liters / normal m of gas. The nozzle in tower 1 is irrigated with acid in the amount of 1 acid per 1 normal M gas (Fig. 3). Each of the nozzles of towers 2 and 3 is irrigated with acid, the amount of 3.3. l / normal m gas.
    120
    The irrigation of the nozzle of the absorption towers is intensified by a pump with a recirculation pipe (not shown in Fig. 3). This pump transports the acid from the sump 23 to the nozzle 4, so that with acid flow (Fig. 3), the nozzle is irrigated with a total amount of acid 4 l / normal m of gas. The temperature of the acid at the outlet of the heat exchangers 47 and 25 is 65С. The temperature of the acid at the outlet of the heat exchangers 14.18 and 30 is in the range of 30-40 ° C. The recycling acid is characterized by the following density (in terms of temperature), kg / l:
    Nozzles 43 and 491.5
    (48.1 59.9 wt.)
    Nozzles 4 and 51,67
    (57.9Be 74.66 wt.%)
    Nozzles 2 and 3 - 1, 56
    . (51,, 2 weightD
    ). . . ;
    Nitrogen oxides absorbed in nozzles 4 and 5 of the absorption tower are fed by pump 22 through line 26 to the nozzle of tower 1, in which these oxides of nitrogen, having turned into NO as a result of interaction with S02, enter the gas flow coming out of the nozzle of tower 1 through the pipeline 7. The more nitrogen oxides are contained in the gas stream, the more efficient is the treatment of S0 / j in nozzles of towers 2 and 3.
    An amount of 1 liter of nitroz-containing acid / normal m of gas is supplied via pipeline 2b to the tower packing 1. The more nitrosis in the bundle, the more containing can be worked out in the system. However, if the content of nitrosis in the acid is too high, the content of nitric oxide in the exhaust gases of the system increases. To regulate the content of nitrosis in the acid in the settling tank 23, nitric acid supplied to the collector 35 through the pipeline 36. is pumped from the collector 35 by the pump 40 through the valve 41 through the pipeline to the nozzle of the tower 2.
    Nitrogen oxides} released in the nozzle of the tower 2 and the next tower 3, pass through the gas pipelines 8 and O into the nozzle 4 of the absorption tower, where they are absorbed by sulfuric acid and transported to the settling tank 23. When introducing gas in the amount of AOO, it is normal with a nitrose concentration in acid in the settling tank, 23 wt D calculated on nitric acid) in the pipeline 52 exhaust gas from the entire system, which contains 50-100 ppm, is obtained. N0 and 200N0. If the amount is 300 ppm the gas system is dim in VI / h instead of 00 500 normal m / h instead of normal m / h or if the content of SO / ji increases with a constant amount of incoming gas, the system cannot completely process all of the SO contained in the gas 2 and part of it enters the absorption zone. As a result, the N0 content in the exhaust gases increases. To increase the amount of SOi without significant loss of nitrogen oxides, it will be necessary to increase the concentration of nitrosis in the acid that is fed to tower 1 and / or increase the amount of acid1 that is supplied to tower 1. If 500 MVV is required to be processed, the concentration of nitrosa in the acid in the sump 23 can be increased to approximately 3% by weight (based on nitric acid) if the usual amount I for irrigating the nozzle in tower 1 is 1 l. acid to 1 normal mill. If instead of one of the two measures described, nitric acid is added to the nozzle of the denitration tower 11, then this addition should be carried out gradually, since it takes several minutes to change the content of nitrogen oxides in gases below the absorption line. zone. Adding too much nitric acid or too much lower SOj content. in the incoming gases leads to an increase in the content of N0 "and, consequently, to the appearance of a yellow color in the exhaust gases of the system .. To eliminate the yellow color, it is necessary to increase the acid concentration in the denitration zone and in the absorption zone, for which it is necessary to reduce or stop the addition water or dilute acid. However, it takes several hours before the concentration of N02 exhaust gases decreases again to kQO ppm. 11. 22 With the implementation of the proposed method, it is possible to compensate for the increase or decrease in the content of ZO in the incoming gases, as well as the change in the volume of the flow of CO containing gas without significant losses of nitrogen oxides with the exhaust gases discharging into the flue of the installation. An increase in the content of S0; 2-gas to be treated causes an increase in the content of MO in gases, which is continuously measured by analyzer 42 below the absorption zone, for example, 100-150 ppm. above normal operating values. Then an automatic adjusting device includes an ftO pump, which pumps over sulfuric acid at a concentration of 20 wt. nitric acid, from the collector 35 to the nozzles of the towers 43 and 2. Valves 53 and 1 are adjusted so that Oh, l / min of acid enters the nozzle of the k3 tower and 0.6 l / min of acid into the nozzle of the tower 2. After a short delay (2 min) the content in the gas at the outlet of the absorption zone falls below 100 ppm. and the kQ pump is stopped. Nitric acid added to the diluted acid of the two recirculation circuits in the towers and 2, respectively, is consumed in approximately 15 minutes and is released as gaseous nitrogen oxides, which are absorbed by the acid in the absorption zone, as a result of which the nitrose content in the acid in the sump 23 is increasing. However, an increase in the nitrosis content is still not enough to cause a reaction in the nozzle of the denitration zone commensurate with the increased content of 80 in the gas stream. After approximately 12 minutes, the N0 content in the exhaust gases again increases to more than 150 ppm. while the N0, j content falls from a maximum of 250 ppm. to values below 150 ppm The analyzer 42 switches on the pump kQ and after 2 minutes the maintenance of N0 in the gas below the absorption zone falls below 100, etc., after its pump 40 is turned off. This switch-on and switch-off operation of the pump 40 is repeated until the eye has a nitrosis content, and in settling 23 there is an increase in the SO content in the gas stream entering the pipeline 6 for further processing in the system. The closer the 239 nitrosa content in the sump 23 is to the value required for the complete treatment 50 in the system, the longer the time interval between the two periods of pump operation. On the other hand, if the concentration of S0.1 in the gas to be treated decreases or increases, the content of NOj in gases increases below the absorption zone and the content of N0 falls well below 100 m, d. The N02 content of the exhaust gases of the absorption zone is measured continuously by the analyzer 57-Eu Pi and the MO content increases by more than 20 ppm per minute and / or if the content increases above 200 ppm. This automatic adjustment device (not shown) shuts down pump 0 if it was turned on. With increasing N0 content by more than 50 ppm. in minutes and / or when the content of N0, more than 300 ppm per minute, an automatic adjustment device of a known type, which reacts to the signal from the analyzer 57, opens valve 38 and turns on pump 58, as a result of which sulfuric acid containing nitrose enters collector 35, whereas sulfuric acid that does not contain nitrosis pumps over pump Pipeline 59 S nozzle 4 of the absorption zone. The amount of acid added and withdrawn is 0.3 liters per 1 normal meter of gas. After approximately 3 minutes, the NOj content in the gases below the absorption zone falls below 200 ppm. and automatic reg. The lidding device closes the valve 38 and turns off the pump 58. By adding nitric acid in the collector 35, a concentration of nitric acid of 20 wt. is reached. During periods of gas entry with a high content of 502. The acid stored in the collector 35 is returned to the system. Sulfuric acid, which comes from collector 3 through a drain pipe, is formed in proportion to the amount processed in the 50g system. The help of the described adjusting devices can maintain the NyO content (amounts of N0 and) in the exhaust gases of the system constantly below 00 MD, even if the amount of gas to be treated or the concentration of S0 ". it often ko I2i | Leblets in a wide range of +70 weight. from the mean daily value. Weight per liter (or density) of recirculating acids is regulated as follows. The density of the acid recirculating through the nozzles of the tower 3 and 9 is maintained at 1.5 kg / l by controlling the heat supply to the heat exchanger (7. Increasing the heat supply intensifies the process of removing water in the nozzle of the tower 49 and therefore increases the acid density. The latter recirculating the nozzles of towers 2 and 3 of the SOj treatment zone are maintained at 1.5b kg / l by adjusting the addition of acid from the sump L ((the corresponding pipelines and valves are not shown). The acid density at the exit of the denitration tower 1 is supported by 1.67 kg / l reg method of reducing the addition of dilute acid from the sump 15 to the tower nozzle 1. Using the proposed method allows you to automate the production of sulfuric acid by the nitrous method and reduce the loss of nitrogen oxides with waste gases. 1. Invention 1. A method for controlling the production of sulfuric acid by the nitrous method from containing dioxide the sulfur of the waste gas stream by adjusting the density of the acid leaving the denitration zone by changing the feed to it with dilute 1 of acid or water, characterized in that order to reduce losses of nitrogen oxides. with waste gases, optionally. regulate the supply of the product containing nitrogen and oxygen compounds to the diluted acid recirculation loop depending on the content of nitrogen oxides in the gas flow of the absorption zone. 2. The method according to claim 1, wherein the content of nitrogen oxides is determined at the inlet or at the outlet or within the absorption zone. 3. The method according to claim G, about tl and h ayu and with the fact that as a product containing compounds of nitrogen and oxygen, use nitric acid or oxides of nitrogen. Sources of information taken into account during the examination 1. For the application of the Federal Republic of Germany No. 2609505, cl. From 01 to 17/82, 1976.
    fug. f
    j
    hh
    权利要求:
    Claims (3)
    [1]
    Claim
    1. A method for controlling the production of sulfuric acid by the nitrous method from a stream of sulfur dioxide-containing exhaust gas by adjusting the density of the acid leaving the denitration zone by changing the supply of dilute acid or water to it, characterized in that, in order to reduce the loss of nitrogen oxides. with flue gases, optional. regulate the supply of a product containing nitrogen and oxygen compounds to the diluted acid recirculation loop depending on the content of nitrogen oxides in the gas stream of the absorption zone.
    [2]
    2. The method according to p. ^ Characterized in that the content of nitrogen oxides is determined at the inlet or at the outlet or inside the absorption zone.
    [3]
    3. The method according to p. D, which includes the fact that as a product containing nitrogen and oxygen compounds, nitric acid or nitrogen oxides are used.
    类似技术:
    公开号 | 公开日 | 专利标题
    US4337230A|1982-06-29|Method of absorbing sulfur oxides from flue gases in seawater
    US3897540A|1975-07-29|Method of controlling reaction conditions in a sulfur dioxide scrubber
    US4657680A|1987-04-14|Wastewater treatment
    US4689156A|1987-08-25|Removal of ammonia from wastewater
    US4784775A|1988-11-15|Removal of hydrogen sulfide from sour water
    US4967559A|1990-11-06|Contaminant abatement process for geothermal power plant effluents
    EP1386654B1|2005-04-06|Method for controlling oxidation in flue gas desulfurization
    US3953578A|1976-04-27|Method for purification of industrial flue gases
    SU980611A3|1982-12-07|Method for controlling production of sulfuric acid by the nitrose method from flow of off-gas containing sulfur dioxide
    US5286389A|1994-02-15|Removal of hydrogen sulfide from sour water
    DE2049438A1|1971-05-06|Process for removing sulfur dioxide from exhaust gases
    CN201669043U|2010-12-15|Ammonia flue gas desulfurization device
    PL185093B1|2003-02-28|Desulphurising method and apparatus employing an electron beam
    CN104174272A|2014-12-03|Method and device for treating a gas flow charged with sulphur dioxide
    RU2694750C2|2019-07-16|Removal of hydrogen sulphide and regeneration of sulphur from gas stream by direct catalytic oxidation and reaction of claus
    US5538707A|1996-07-23|Acid concentration control in SO3 absorption
    US4371508A|1983-02-01|Method for operating a flue gas desulfurization
    CA1115494A|1982-01-05|Process for the removal of sulfur oxidesfrom exhaust gases using slurry of red mudcontaining calcium ion
    EP0824953B1|2003-05-14|Flue gas desulfurization process comprising a method for measuring oxidation-reduction potential
    SU1699900A1|1991-12-23|Method for straining plant for preparation sulfuric acid by nitrous method
    GB2035980A|1980-06-25|Purifying Waste Gases Containing Nitrous Gases
    US2006031A|1935-06-25|Apparatus for the manufacture of sulphuric acid
    CA1293359C|1991-12-24|Process for removing oxides of nitrogen and sulfur from waste gases
    BG62925B1|2000-11-30|Method and equipment for the manufacture of fertilizer from sulphur oxides-containing gas
    SU1729277A3|1992-04-23|Method of nitrogen oxides removal from excreted gases
    同族专利:
    公开号 | 公开日
    ZA784133B|1979-07-25|
    FI782255A|1979-01-22|
    PL208579A1|1979-04-23|
    AT372619B|1983-10-25|
    EP0000515A1|1979-02-07|
    CA1103899A|1981-06-30|
    DE2830214C2|1989-03-16|
    PL111169B2|1980-08-30|
    IT7850388D0|1978-07-20|
    ATA526178A|1983-03-15|
    BR7804687A|1979-04-17|
    AU528394B2|1983-04-28|
    ES471907A1|1979-02-01|
    DE2830214A1|1979-02-08|
    EP0000515B1|1981-12-02|
    IN149347B|1981-10-31|
    FI65978C|1984-08-10|
    US4242321A|1980-12-30|
    AU3820078A|1980-01-24|
    DD137916A5|1979-10-03|
    FI65978B|1984-04-30|
    JPS5452672A|1979-04-25|
    JPS6332723B2|1988-07-01|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    BE501481A|
    US1486757A|1923-05-31|1924-03-11|Jensen Ernst|Method of automatic regulation of the supply of oxidizing agents, such as nitric acidnitrate solution, or others in the manufacture of sulphuric acid|
    US1889973A|1924-06-06|1932-12-06|Silica Gel Corp|Chamber process of manufacturing sulphuric acid|
    US1800786A|1926-08-12|1931-04-14|Andrew M Fairlie|Ammonia oxidation equipment and the use thereof for the manufacture of sulphuric acid|
    GB270988A|1926-10-12|1927-05-19|Hugo Petersen|Improvements in and relating to the manufacture of sulphuric acid|
    GB363327A|1929-06-11|1931-12-11|Industrikemiska Ab|Improvements in and relating to the production of sulphuric acid|
    NL37191C|1931-11-12|
    FR1072033A|1953-01-08|1954-09-07|Saint Gobain|Method and apparatus for controlling the operation of sulfuric acid manufacturing plants|
    DE1140909B|1959-10-06|1962-12-13|Ruhr Schwefelsaeure Ges Mit Be|Process for controlling the rate of oxidation of sulfur dioxide and nitrogen oxides in a system for the production of sulfuric acid using the nitrogen oxide method|
    DE2510294A1|1975-03-10|1976-09-23|Ciba Geigy Ag|PROCESS FOR SEPARATING SO DEEP 2 FROM GAS TROEMS WITH THE RECOVERY OF SULFUR ACID BY THE NITROGEN OXIDE PROCESS|DE1900701C3|1969-01-08|1980-08-07|Hauni-Werke Koerber & Co Kg, 2050 Hamburg|Method and arrangement for controlling the start-up and / or stopping of a machine for producing cigarettes or other rod-shaped tobacco articles|
    US4400362A|1981-11-04|1983-08-23|Lerner Bernard J|Removal of nitrogen oxides from gas|
    EP0174907A3|1984-08-13|1989-10-25|Ciba-Geigy Ag|Process for removal of nitrogen and sulphur oxides from off gases|
    US4716066A|1985-04-16|1987-12-29|Wam-Plast Ag|Filling body of acid-resistant synthetic plastics material|
    DE4127075A1|1991-08-16|1993-02-18|Nymic Anstalt|METHOD FOR CLEANING LOADED EXHAUST GAS FROM COMBUSTION PLANTS|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    CH906377|1977-07-21|
    [返回顶部]