JP2005097542A - Apparatus for treating hydrocarbon-containing gas and method for treating hydrocarbon-containing gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for treating a hydrocarbon-containing gas and a method for treating a hydrocarbon-containing gas that make it possible to calculate an amount of NO<SB>X</SB>introduced into an olefin recovery means during the process of feeding a gas composed mainly of hydrocarbons such as FCC off-gases as a raw material gas to the olefin recovery means to recover olefins from the raw material gas. <P>SOLUTION: The apparatus (1) for treating a hydrocarbon-containing gas has an olefin recovery means and a raw material gas feeding means for feeding a raw material gas to the olefin recovery means and is provided with an adsorbing tower filled with an NO<SB>X</SB>adsorbent and an extracted gas feeding means for gas-extracting a part of the raw material gas to introduce the extracted gas into the adsorbing tower. The method (2) for treating a hydrocarbon-containing gas comprises gas-extracting a part of the raw material gas and introducing the extracted gas into the adsorbing tower filled with the NO<SB>X</SB>adsorbent to allow NO<SB>X</SB>to be adsorbed, then measuring an amount of the adsorbed NO<SB>X</SB>to calculate an amount of NO<SB>X</SB>introduced into the olefin recovery means based on the measured amount of adsorbed NO<SB>X</SB>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention belongs to a technical field related to a hydrocarbon-containing gas processing apparatus and a hydrocarbon-containing gas processing method, and particularly, when supplying a hydrocarbon-containing gas containing a trace amount of NO _X to an olefin recovery means, The present invention belongs to a technical field related to an apparatus and a method for determining the amount of NO _X introduced.

NO _X analytical techniques, NO _X removal technology has historically it has progressed sophistication with air pollution problems. In Japan, the momentum of technological development has gradually increased since the 1970s when pollution became a social problem. Recently, countermeasures for exhaust gas containing about several hundred ppm of NO _X discharged from factories and the like have progressed and have almost calmed down, but interest in air pollution from automobile exhaust gas has moved, and low concentration NO of several ppm or less _It is necessary to develop more advanced NO _X removal technology and NO _X analysis technology for _X.

The NO _X removal techniques, and NO _X contained in the exhaust gas of an automobile or the like, and hit by limelight for the removal of low concentration of the NO _X which had been released into the atmosphere from mobile sources such as automobiles, many researchers And developers have come up with issues. For example, as an adsorbent for realizing the removal of low-concentration NO _x , described in JP-A Nos. 6-21925, 8-38888, 8-38889, and 9-313883 There is something that was done. These things publication, either, the NO _X at a high removal rate to the original room temperature a development example of the adsorbent to adsorb and remove, but not completely eliminated, the original low concentrations of NO Progress has been made to a level that meets the objective of removing _X to a higher degree and purifying the air environment.

In order to support such technology development, highly reliable analysis technology and evaluation technology are required. With the demand for advanced NO _X removal technology, analysis methods for lower concentrations of NO _X are also becoming more sophisticated.

Regarding NO _X analysis technology, JIS K 0104 [Japan Standards Association, “JIS Handbook Environmental Measurement I”, January 31, 2003, p. 442-467 (Non-patent Document 1)], various chemical analysis methods (Salzman method, NEDA method, Zn-NEDA method, PDS method, ion chromatograph method), JIS B 7982 [Japan Standards Association, "JIS Handbook" Environmental Measurement I ”, January 31, 2003, p. Various automatic measuring instrument methods (chemiluminescence method, infrared absorption method, ultraviolet absorption method) defined in [1261-1284 (non-patent document 2)] are known.

The Salzmann method is a method in which NO ₂ is absorbed using a sulfanilic acid-naphthylethylenediamine acetic acid solution as an absorbing color developing solution, and the absorbance at the time of coloring is measured.

The NEDA method (naphthylethylenediamine method) is a method in which NO _X is absorbed in a basic hydrogen peroxide solution-sodium formate solution to form nitrite ions, and sulfanilamide and naphthylethylenediamine are added to develop color and measure absorbance.

In the Zn-NEDA method (Zinc-reduced naphthylethylenediamine absorptiometric method), NO _X is oxidized with ozone, absorbed into dilute sulfuric acid to nitrate ions, and reduced to nitrite ions with zinc powder, and sulfanilamide and naphthylethylenediamine are added. In addition, the color is developed and the absorbance is measured.

The PDS method (phenol disulfonic acid absorptiometric method) is a method in which NO _X is oxidized with ozone, absorbed in sulfuric acid-hydrogen peroxide solution to form nitrate ions, and color is developed by adding phenol disulfonic acid to measure absorbance. The ion chromatographic method is a method in which nitrate ions are converted into the same amount by the same method and quantified by ion chromatography.

When NO ₂ and the fractional determination NO, when the no analysis to oxidize NO in the test gas NO ₂ can be measured, the sum of the by oxidizing NO analyzed instead of NO ₂ NO ₂ and NO Since it can be measured, NO ₂ and NO can be calculated from the respective measured values. In the Salzmann method, a potassium permanganate solution is used as the oxidizing agent. In other methods, to calculate the the presence or absence of oxidation processes that are included in some NO _X (oxidation step Yes) and NO ₂ (Mu oxidation step) to measure NO ₂ and NO procedures.

In recent years, instrumental analysis methods have progressed, and NO _X meters using chemiluminescence methods have become more reliable. The analysis principle is that NO is reacted with ozone to form NO _{2 in} an excited state, and NO concentration is measured from the emission energy when returning to NO ₂ in the ground state. When the fractional determination of NO ₂ and NO, and a measure of the NO _X by reduction of NO _X total volume NO, calculates the NO ₂ from a measure of the NO by omitting the reduction step.

Both flue gas, metal surface treatment process, inorganic and organic chemical reaction process, which has been devised as NO _X analytical method in an exhaust gas generated from such denitration process, made possible the measurement of up to several ppm I came. An analysis of about several ppb may be measurable, but there are restrictions on the analysis target, and it is considered applicable only in special cases.

These methods have also already up proven practical technologies, there is for the purpose of analysis of the NO _X in the small atmospheric of exhaust gas and the concentration variation containing a relatively high concentration of the NO _X, any gas Even NO _X in the middle does not mean that a highly reliable analysis is possible.
Japanese Standards Association, “JIS Handbook Environmental Measurement I”, January 31, 2003, p. 442-467 (JIS K 0104) Japanese Standards Association, “JIS Handbook Environmental Measurement I”, January 31, 2003, p. 1261-1284 (JIS B 7982)

In addition Sekiru thing to air pollution, as an example of removal techniques and analytical techniques of trace NO _X has become important, and analysis techniques and removal techniques traces NO _X in the FCC off-gas. FCC off-gas is a gas discharged after the target substance is separated and recovered in the fluidized bed cracking (FCC) process of petroleum refining and contains useful low-boiling fractions such as ethylene and propylene. Is used as fuel. In recent years, in the trend of energy and resource saving, there has been a movement to recover useful components in this off-gas, and since 2000, a combinatorial renaissance plan has been started as a national project.

The recovery of useful substances in FCC offgas is described in detail in the following documents.
・ A NOVEL PROCESS RECOVERS OLEFINS FROM CRACKER OFFGAS,
WHIsaiski & B. Pacalowska, CEMICAL ENGINEERING, November 133 (1996)
・ OLEFIN RECOVERY FROM FCC OFFGAS CAN PAY OFF,
Michael.G.Brahn, OIL & GAS JOURNAL, 20 April 94 (1992)
・ ECONOMICALLY RECOVER OLEFINS FROM FCC OFFGASES,
D.Netzer, HYDROCARBON PROCESSING, APR 83 (1997)
・ NO _X in the Cryogenic Hydrogen Recovery Section of an Olefins Production Unit, WHHenstock, Plant / Operations Progress, 5 (4) 232 (1986)

According to these documents, the FCC off-gas contains C4 + as hydrogen, nitrogen, methane, ethane, ethylene, propylene, and other trace hydrocarbons along with trace amounts of NO _X. In order to separate and purify useful components of), it is necessary to remove non-condensed light components such as hydrogen at a low temperature and then add them to an ethylene splitter for purification. At this time, trace amounts of NO _X polymerize with each other at −100 ° C. or lower to form an explosive substance called NO _X gum. Since NO _X gum accumulates at low temperatures, it is known that if NO _X gum is not washed away, it will concentrate and cause an initial explosion for some reason, causing expansion and combustion of low temperature liquefied gas, Plant operation is at risk. In fact, examples of explosions of NO _X gum in hydrocarbons at low temperatures are introduced in the following literature.

  Risk of Nitric Oxide in Cryogenic Gas Separator, Haseba et al., Safety Engineering, 8 (1) 22 (1969)

For safe plant operation, it is necessary to stop the operation periodically and to deal with the equipment by washing the equipment with methanol or the like. The frequency of regular maintenance at a plant that recovers useful components from FCC offgas greatly affects the productivity of the plant as well as from the viewpoint of safe operation. This is because it is desirable to avoid danger caused by NO _{X in} FCC off-gas, and it is recognized as one of the important technical issues in the above-mentioned national project. This risk avoidance measure requires not only NO _X removal technology but also NO _X analysis technology. No matter how advanced NO _X removal technology is, it is impossible to make the removal rate zero, and it is not possible to neglect the analysis and evaluation technology for determining the periodic maintenance interval. However, at present, NO _X removal technology for coping with the above-mentioned problems has not been established, and even reliable NO _X analysis technology has not been found. In order to achieve the above problems, NO _X removal technology and NO _X analysis technology need to be developed while complementing each other.

With conventional analytical techniques, quantitative analysis of NO _X contained in FCC gas is extremely difficult. One reason is that highly reliable quantitative values are required even for very low concentrations of NO _X. During plant operation, brought into the process for NO _X is prolonged even trace amounts, since it is stored as NO _X gum is assumed, the order of ppb level to determine without mistaking the preservation time This is because it is necessary to detect the NO _X concentration. Another reason is that the coexisting gas is mainly hydrocarbon. In conventional targeted at NO _X in the air technology, for receiving the interference effects such as hydrocarbons, because we must consider how to eliminate the influence of these components.

The prior art for quantifying NO _X is as described above. Among them, in the analysis method using the absorbing solution, NO _x absorption efficiency 100% in the absorbing solution is guaranteed, or even if 100% is not obtained, if the absorption efficiency is not a constant value, the reliability High analysis is not possible. Since the follow-up to the NO _X concentration fluctuation is not good, a highly reliable analysis cannot be performed except when the NO _X concentration level shifts to a nearly constant value. In addition, it has been clarified that there is a case where an accurate analysis cannot be performed due to a problem of interference when hydrocarbons, particularly olefins coexist. Furthermore, it is known that FCC off-gas contains acidic and basic components such as hydrogen sulfide and ammonia at a higher concentration than NO _X , and these components are also expected to react with the absorbing solution. . In any case, NO _X analysis in FCC off-gas is problematic because it is not easy due to the presence of chemical species that act as interfering components with respect to conventional NO _X analysis methods.

Also in the chemiluminescence method, hydrocarbons and the like are problematic as interference components. Therefore, after separating the interference component in the preceding stage of the gas chromatographic, a method of quantifying is proposed by chemiluminescence analysis limit is not sufficient, as the monitors traces NO _X remains the development issues Yes.

As described above, it can be seen that the conventional NO _X analysis method is not suitable for the determination of a trace amount of NO _X contained in the FCC offgas. There is a demand for a method for accurately and quantitatively evaluating the total amount of NO _X when a low concentration of NO _X is brought into the process for a long time.

The present invention has been made paying attention to such circumstances, and its purpose is to supply a gas mainly composed of hydrocarbons such as FCC off-gas as a raw material gas to the olefin recovery means to recover the olefin from the raw material gas. In doing so, an object of the present invention is to provide a hydrocarbon-containing gas processing apparatus and a hydrocarbon-containing gas processing method capable of determining the amount of NO _x introduced into the olefin recovery means.

  In order to achieve the above object, the present inventors have intensively studied, and as a result, completed the present invention. According to the present invention, the above object can be achieved.

  The present invention completed as described above and capable of achieving the above object relates to a hydrocarbon-containing gas processing apparatus and a hydrocarbon-containing gas processing method, and contains hydrocarbons according to claims 1 to 5 in the claims. A gas treatment device (hydrocarbon-containing gas treatment device according to first to fifth inventions), a hydrocarbon-containing gas treatment method according to claims 6 to 13 (hydrocarbon-containing gas treatment method according to sixth to thirteenth inventions), It has the following configuration.

That is, the hydrocarbon-containing gas processing apparatus according to claim 1 has an olefin recovery means for recovering olefin from a raw material gas mainly composed of hydrocarbon, and a raw material gas supply means for supplying the raw material gas to the olefin recovery means. And an adsorption tower filled with NO _X adsorbent and extraction gas supply means for extracting a part of the raw material gas and introducing it into the adsorption tower, and the amount of NO _X adsorbed on the NO _X adsorbent is measured. Measured and introduced into the olefin recovery means on the basis of the measured amount of NO _X and the ratio of the amount of source gas supplied by the source gas supply means and the amount of source gas extracted by the extraction gas supply means This is a hydrocarbon-containing gas processing apparatus characterized in that the obtained NO _x amount is obtained [first invention].

The hydrocarbon-containing gas treatment device according to claim 2, wherein the NO _X adsorbent is composed of at least one selected from a copper-manganese composite oxide, an iron-manganese composite oxide, and a non-basic oxide. 2. The hydrocarbon-containing gas processing apparatus according to claim 1, wherein a ruthenium compound is supported on the carrier [second invention].

Hydrocarbon-containing gas processing apparatus according to claim 3, the NO _X adsorbent is copper - manganese oxide, iron - hydrocarbon containing at least one from the consisting claim 1 selected from manganese composite oxide A gas processing apparatus [third invention].

  The hydrocarbon-containing gas treatment apparatus according to claim 4, wherein the adsorption tower is a first adsorption tower in which an adsorbent in which a ruthenium compound is supported on a carrier made of a non-basic oxide, and a copper-manganese composite oxidation. And / or an adsorbent having a ruthenium compound supported on a support made of iron-manganese composite oxide, or an adsorbent made of at least one selected from copper-manganese composite oxide and iron-manganese composite oxide The first adsorption tower and the second adsorption tower in the order in which the source gas extracted by the extraction gas supply means is introduced into the first adsorption tower and then introduced into the second adsorption tower. The hydrocarbon-containing gas treatment device according to any one of claims 1 to 3, wherein the adsorption tower is connected in series [fourth invention].

  The hydrocarbon-containing gas treatment device according to claim 5 has means for mixing an oxygen-containing gas with the raw material gas introduced into the adsorption tower, and means for adjusting the amount of the oxygen-containing gas to be mixed. 4. A hydrocarbon-containing gas processing apparatus according to any one of [4] [5th invention].

The hydrocarbon-containing gas treatment method according to claim 6 is a hydrocarbon-containing gas treatment method in which a raw material gas mainly composed of hydrocarbons is supplied to the olefin recovery means by the raw material gas supply means and the olefin is recovered from the raw material gas. , a portion of the raw material gas is introduced into the extraction to NO _X adsorption tower adsorbent is filled, after the NO _X adsorbed in the NO _X absorbent, and measuring the amount of NO _X the adsorbed, the A hydrocarbon-containing gas treatment method characterized in that the NO _x amount introduced into the olefin recovery means is determined based on a ratio between the amount of the raw material gas supplied by the raw material gas supply means and the amount of the extracted raw material gas. [Sixth Invention]

The hydrocarbon-containing gas treatment method according to claim 7, wherein the NO _X adsorbent is ruthenium on a carrier comprising at least one of a copper-manganese composite oxide, an iron-manganese composite oxide, and a non-basic oxide. 7. The hydrocarbon-containing gas treatment method according to claim 6, wherein the compound is supported [Seventh Invention].

The hydrocarbon-containing gas treatment method according to claim 8, wherein the NO _X adsorbent comprises at least one of a copper-manganese composite oxide and an iron-manganese composite oxide. [Eighth Invention]

  The hydrocarbon-containing gas treatment method according to claim 9, wherein the extracted raw material gas is introduced into the adsorption tower before or after the oxygen-containing gas is mixed with the raw material gas and mixed in the mixed gas. The method for treating a hydrocarbon-containing gas according to any one of claims 6 to 8, wherein the oxygen concentration of the gas is adjusted to more than 0 vol% and not more than 20 vol% [9th invention].

The hydrocarbon-containing gas treatment method according to claim 10, wherein the NO _X amount adsorbed on the NO _X adsorbent is measured by extracting the NO _X by immersing the NO _X adsorbent in an extract and then extracting the NO _X. It is the hydrocarbon containing gas processing method in any one of Claims 6-9 performed by measuring the nitrate ion and / or nitrite ion in a liquid [10th invention].

Hydrocarbon-containing gas treatment method according to claim 11, wherein, after adsorbing the NO _X in the NO _X adsorbent filled in the adsorption tower, and heating the adsorption tower above 650 ° C. desorbed gas, which NO _x in the desorption gas generated by the above is absorbed by the collection liquid, and the amount of NO _X adsorbed on the NO _X adsorbent is measured by measuring nitrate ions and / or nitrite ions in this solution The hydrocarbon-containing gas treatment method according to any one of claims 6 to 9, wherein the eleventh invention is performed.

Hydrocarbon-containing gas treatment method according to claim 12, wherein, after adsorbing the NO _X in the NO _X adsorbent filled in the adsorption tower, and heating the adsorption tower above 650 ° C. desorbed gas, which The hydrocarbon-containing gas treatment according to any one of claims 6 to 9, wherein the NO _x amount adsorbed on the NO _x adsorbent is measured by measuring NO _x in the desorption gas generated by the chemical analysis by chemical analysis. It is a method [12th invention].

Hydrocarbon-containing gas treatment method according to claim 13, wherein, after adsorbing the NO _X in the NO _X adsorbent filled in the adsorption tower, and heating the adsorption tower above 650 ° C. desorbed gas, which The hydrocarbon-containing gas treatment according to any one of claims 6 to 9, wherein the NO _x amount adsorbed on the NO _x adsorbent is measured by measuring NO _x in the desorption gas generated by the above by instrumental analysis. It is a method [13th invention].

According to the hydrocarbon-containing gas treatment method according to the present invention, a hydrocarbon-based gas such as FCC off-gas is supplied to the olefin recovery means as a raw material gas, and is introduced into the olefin recovery means when recovering the olefin from the raw material gas. it will allow to determine the amount of NO _X was.

According to the hydrocarbon-containing gas processing apparatus of the present invention, a hydrocarbon-based gas such as FCC off-gas is supplied to the olefin recovery means as a raw material gas, and is introduced into the olefin recovery means when recovering the olefin from the raw material gas. it becomes possible to perform the hydrocarbon-containing gas treatment, which can determine the amount of NO _X was.

The inventors of the present invention have intensively studied to achieve the above-mentioned object. As a result, hydrocarbon-based gas such as FCC off-gas was introduced into the adsorption tower packed with NO _X adsorbent (adsorbent that adsorbs NO _X ), and NO _X was adsorbed on this NO _X adsorbent. after, by measuring the adsorbed amount of NO _X it was found that it is possible to determine _the amount of NO _X in the gas (concentration). According to this method, even very low concentrations NO _X containing gas which can not be measured _the amount of NO _X in the conventional of the NO _X analysis as FCC offgas, NO _X is analyzed to capture the NO _X adsorbent possible by a considerable amount setting adsorption time to the extent that would be, it is possible to obtain _the amount of NO _X in the gas (concentration). That is, even when a very low concentration of NO _X in the gas as FCC offgas, is adsorbed until the NO _X in the analyzable amount corresponding to the NO _X adsorbent, measured NO _X adsorbed in the NO _X adsorbent By doing so, the NO _x concentration in the gas can be obtained.

  The present invention has been completed based on the above-described knowledge, and is a hydrocarbon-containing gas processing apparatus and a hydrocarbon-containing gas processing method having the above-described configuration.

The hydrocarbon-containing gas processing apparatus according to the present invention thus completed comprises an olefin recovery means for recovering olefin from a raw material gas mainly composed of hydrocarbon, and a raw material gas supply for supplying the raw material gas to the olefin recovery means. And an adsorption tower filled with NO _X adsorbent, and extraction gas supply means for extracting a part of the raw material gas and introducing it into the adsorption tower, and adsorbed on the NO _X adsorbent measuring the amount of NO _X, the a measured amount of NO _X, based on the ratio of the raw material gas volume bled by the extracted gas supply means as a raw material gas amount supplied by the raw material gas supply means, wherein the olefin A hydrocarbon-containing gas processing apparatus configured to determine the amount of NO _x introduced into the recovery means [first invention].

The hydrocarbon-containing gas treatment method according to the present invention is a hydrocarbon-containing gas treatment method in which a raw material gas mainly composed of hydrocarbons is supplied to the olefin recovery means by the raw material gas supply means and the olefin is recovered from the raw material gas. Te, a portion of the raw material gas is introduced into the extraction to NO _X adsorption tower adsorbent is filled, after the NO _X adsorbed in the NO _X absorbent, and measuring the amount of NO _X the adsorbed, A hydrocarbon-containing gas treatment characterized in that the NO _x amount introduced into the olefin recovery means is obtained based on a ratio between the amount of the raw material gas supplied by the raw material gas supply means and the amount of the extracted raw material gas. It is a method [6th invention].

In the hydrocarbon-containing gas treatment method according to the present invention, a part of the raw material gas is introduced into the extraction to NO _X adsorption tower adsorbent is filled, after the NO _X adsorbed in the NO _X absorbent, since the way to measure this adsorbed amount of NO _X, can be determined _the amount of NO _X in the raw material gas is the bleed. That is, the NO _X adsorbent time to adsorb the NO _X (the adsorption time), by setting the degree of adsorption NO _X becomes analyzable considerable amount, determine the amount of NO _X in the raw material gas which is the extraction be able to. Therefore, it is possible to determine the amount of NO _X introduced to an olefin recovery unit from the amount of NO _X. That is, it is possible with this amount of NO _X, based on the ratio of the raw material gas amount which is the extracted raw material gas amount supplied by the raw material gas supply means, determining the amount of NO _X introduced into the olefin recovery means .

Therefore, according to the hydrocarbon-containing gas processing method according to the present invention, when the olefin is recovered from the raw material gas by supplying a gas mainly composed of hydrocarbons such as FCC off gas to the olefin recovery device as the raw material gas, The amount of NO _X introduced in can be determined. Consequently, to avoid the risk caused by the NO _X (the explosion of the NO _X gum) in order to secure plant operation, rather than that the treatment of the equipment such as washing simply periodically stopping the operation, Since it is possible to determine an accurate periodic maintenance interval that matches the actual situation and to perform equipment cleaning and the like at an appropriate time, it is reasonable and the safety is enhanced. Furthermore, in the olefins recovery unit, or in the case of providing the NO _X removal means from the raw material gas is in the front, knowing the extent of the required time and required NO _X removal of the NO _X removal from the raw material gas, etc. Since NO _X removal can be performed above, more accurate NO _X removal can be performed.

The hydrocarbon-containing gas processing apparatus according to the present invention has an olefin recovery means for recovering olefin from a raw material gas mainly composed of hydrocarbon, and a raw material gas supply means for supplying the raw material gas to the olefin recovery means, and NO _X adsorbent loaded adsorption column, since a part of the raw material gas is extracted and a bleed gas supply means for introducing into the adsorption tower, bled and NO _X adsorbing a portion of the raw material gas It can be introduced into an adsorption tower packed with an agent, and this NO _X adsorbent can adsorb NO _X. At this time, NO _X can be adsorbed to such an extent that the adsorbed NO _X becomes an amount that can be analyzed. Therefore, after the NO _X adsorbed in the NO _X absorbent, by measuring the amount of NO _X The adsorbed, it is possible to obtain the amount of NO _X in the raw material gas is the bleed. Thus, the the amount of NO _X, based on the ratio of the raw material gas amount which is the extracted raw material gas amount supplied by the raw material gas supply means, is possible to determine the amount of NO _X introduced into the olefin recovery means it can.

Therefore, according to the hydrocarbon-containing gas processing apparatus according to the present invention, when the raw material gas mainly composed of hydrocarbons is supplied to the olefin recovery means and the olefin is recovered from the raw material gas, the NO _X introduced into the olefin recovery means. It becomes possible to perform a hydrocarbon-containing gas treatment whose amount can be determined.

According to the method for determining the amount of NO _X as described above (hereinafter also referred to as the NO _X amount measuring method according to the present invention), the NO _X amount cannot be measured by the conventional NO _X analysis method like FCC offgas. Even with a very low concentration of NO _X -containing gas, if the adsorption time is set so that the amount of NO _X trapped in the NO _X adsorbent can be analyzed, the amount of NO _X can be determined. The amount of NO _x brought into the process (olefin recovery process, etc.) during the period can be quantified. The NO _X amount measurement method according to the present invention can be a more useful method when the total amount of NO _X becomes a problem than the instantaneous NO _X concentration. This is optimal for purposes such as grasping the total amount of NO _X contained in FCC off-gas. That is, in order to ensure safety during operation, the intended analysis means to evaluate the NO _X amount which brought into the process, more intermittently monitoring the instantaneous of the NO _X concentration, but rather directly And high reliability.

When a large amount of gas is supplied to the process as a raw material, and NO _X contained in the gas quantifies low concentration NO _X at a level where it is difficult to measure the concentration with the prior art, NO according to the present invention _{The X} amount measurement method is a particularly effective means.

Thus, the NO _X amount measuring method according to the present invention can quantitatively evaluate the NO _X amount brought into the process with high accuracy.

The present invention applies such a method for measuring the amount of NO _X (the method for measuring the amount of NO _{X according to the} present invention). In the present invention, for example, a predetermined flow rate bleed a small portion of the uniformly mixed raw material gas inlet portion of the olefins recovery process, NO _X adsorbent is induced in the adsorption tower filled. The adsorbent packed in the adsorption tower captures NO _X. At this time, it is desirable to capture the entire amount of NO _X. The average NO _x concentration can be measured by quantifying the NO _x trapped in the adsorbent after a predetermined time. Therefore, if the flow rate of the raw material gas introduced into the olefin recovery process is known, the amount of NO _X accompanying can be estimated.

In the present invention, it is desirable that the NO _X adsorbent used captures the entire amount of NO _X in the extracted source gas without loss, from the viewpoint of NO _X amount measurement accuracy. When the NO _X capture rate is small, the NO _X amount measurement accuracy is low, and as the NO _X capture rate is large, the NO _X amount measurement accuracy is high. As a result of intensive studies, the present inventors have found that a ruthenium compound is supported on a support composed of one or more of a copper-manganese composite oxide, an iron-manganese composite oxide, and a non-basic oxide as an NO _X adsorbent. Alternatively, it has been found that when one comprising at least one of a copper-manganese composite oxide and an iron-manganese composite oxide is used, the NO _X trapping rate is large and a high level of NO _X amount measurement accuracy can be obtained. . Therefore, it is desirable to use such an NO _X adsorbent [second invention, third invention, seventh invention, eighth invention]. When such an NO _X adsorbent is used, the NO _X amount can be quantitatively evaluated with higher accuracy.

In the present invention, the amount of NO _X adsorbed on the NO _X adsorbent is measured, for example, as follows.

That is, after the NO _X were extracted NO _X was immersed in extracts NO _X adsorbent is adsorbed, by measuring the nitrate and / or nitrite ions in the extract Tenth Invention .

Alternatively, after NO _X is adsorbed on the NO _X adsorbent packed in the adsorption tower, the adsorption tower is heated to 650 ° C or higher to desorb the gas, and the NO _X in the desorbed gas generated thereby is collected. This is carried out by absorbing the solution and measuring nitrate ions and / or nitrite ions in the solution [11th invention].

Alternatively, after NO _X is adsorbed on the NO _X adsorbent packed in the adsorption tower, the adsorption tower is heated to 650 ° C or higher to desorb the gas, and the resulting NO _X in the desorbed gas is chemically analyzed. [Twelfth invention].

Alternatively, after NO _X is adsorbed to the NO _X adsorbent packed in the adsorption tower, the adsorption tower is heated to 650 ° C or higher to desorb the gas, and the resulting NO _X in the desorbed gas is analyzed by instrument. [13th invention].

In any case, the amount of NO _X adsorbed in the NO _X adsorbent can be accurately measured. The extraction liquid and collection liquid used here are not particularly limited, but an alkaline aqueous solution that absorbs NO _X , such as Na ₂ CO ₃ , K ₂ CO ₃ , NaHCO ₃ , KHCO ₃ , NaOH, KOH, etc. An aqueous solution of these or a mixed solution thereof is preferred.

In the present invention, the NO _X adsorbent may be a disposable method, but can also be reused.

NO _X adsorbed in the measurement of the adsorbed amount of NO _X in the agent or during playback of the adsorption tower (i.e., during the desorption of gas from the NO _X adsorbent) to be monitored of the NO _X amount is repellent that break were In this case, it is desirable to provide a plurality of adsorption towers and to continuously monitor in a process configuration in which there are always waiting adsorption towers.

  The present invention will be described in more detail and specifically below.

FIG. 1 shows a first embodiment of the present invention. In the case of Embodiment 1 shown in FIG. 1, the adsorption tower (also referred to as NO _X monitor) packed with NO _X adsorbent is a process of supplying a gas mainly composed of hydrocarbons as a raw material gas to the olefin recovery step. Installed in parallel with the raw material gas inlet. It is those with a bleed line branching from the source gas supply to olefins recovery process line (main line) to bleed part of the source gas leads to the adsorption tower, quantification of the NO _X that extraction amount to be described later It is sufficient if an amount sufficient to be detected by the analysis method can be secured.

Conventionally, NO _X analysis methods such as the Salzman method, NEDA method, Zn-NEDA method, and PDS method are synthesized by passing the test gas through the absorption liquid and trapping NO _X , and then by chemical reaction with the absorption liquid. A method for colorimetric analysis of the amount of color developing components has been often used. However, this method is not only it is not suitable for gas fluctuates original NO _X concentration, hydrocarbons, can not be accurately NO _X analysis occurs reaction of hydrogen sulfide, and the like ammonia coexist with absorption liquid. In particular, when NO _X is at a low concentration, the influence of interference caused by hydrocarbons etc. that have passed through the absorbing solution increases until the coloring component reaches the detection limit, and the analysis value is completely meaningless. Do not do.

The NO _x amount measuring method according to the present invention captures NO _x even in a low concentration by using an adsorbent that is difficult to adsorb other than NO _x in order to reduce the interference action of hydrocarbons, etc. The accumulated amount of NO _x can be quantitatively analyzed with high accuracy. In the conventional NO _X analysis technology, it has been impossible to quantify low concentration NO _X when an interference gas is included, but the amount of NO _{X according} to the present invention using the NO _X monitor according to the present invention is not possible. the measurement method, can now be quantified at low concentrations NO _X is reliable with a variation.

  In the present invention, the amount of extraction gas is usually extremely small compared to the amount of gas introduced into the process, so that the gas discharged from the adsorption tower is often exhausted, but is introduced into the process. If the amount is not negligible compared to the amount of gas, for example, as shown in FIG. 1, it may be returned to the process introduction line. When the exhaust gas from the adsorption tower is returned to the introduction line to the process in this way, the useful components in the exhaust gas can be analyzed without being wasted.

It is desirable to capture the entire amount of NO _X in the gas passing through the adsorption tower. Therefore, NO _X adsorbent filled in the adsorption tower, has high affinity for NO _X, i.e., larger NO _X adsorbent equilibrium adsorption amount is preferable. However, even when the NO _x adsorbent with a large equilibrium adsorption amount is filled, it may break through early depending on the operating conditions. Normally, when gas is introduced into the adsorption tower, the adsorbent packed near the entrance of the adsorption tower enters an equilibrium adsorption state, and the region filled with the adsorbent in the equilibrium adsorption state gradually advances to the outlet side over time. Go. The moment when NO _X leaks from the adsorption tower outlet is called breakthrough, but at this time, the entire region of the adsorption tower is not in an equilibrium adsorption state. There is a region that does not reach the equilibrium adsorption amount in the vicinity of the adsorption tower outlet. In the adsorption tower, the region filled with the adsorbent in the state until the adsorption starts and reaches the equilibrium adsorption amount, that is, the region where the mass transfer between the gas phase and the solid phase is called the adsorption zone. The shorter the adsorption band length is, the more efficient adsorption takes place. In order to shorten the adsorption band length, the smaller the adsorbent particle size, the more advantageous, and the smaller the linear velocity of the gas passing through the adsorption tower, the more advantageous. In the operation method of the adsorption apparatus of the present invention, the adsorbent particle size and linear velocity are not limited, but in order to take a long monitoring time, it is advantageous that the adsorbent particle size is small, and the adsorption tower It is preferable to make the linear velocity of the gas passing through the chamber small. What is necessary is just to set the adsorbent particle size and gas flow rate suitable for ensuring a fixed flow volume, considering pressure loss.

As the NO _X adsorbent, in the case where it is not necessary to separate NO ₂ and NO, those in which a ruthenium compound is supported on a support made of a copper-manganese composite oxide or an iron-manganese composite oxide are suitable. The function of this adsorbent will be described below.

The main components constituting NO _X are NO ₂ and NO. For example, in the atmosphere, in the coexistence system with oxygen, these components exist in an almost equilibrium composition. NO ₂ is a component that is relatively easy to adsorb, but NO is a component that is difficult to adsorb. The present inventors previously invented the above adsorbent as a removal agent for low-concentration NO _X contained in the gas in the automobile tunnel, but this is obtained by oxidizing NO to NO ₂ and capturing it in the adsorbent. It was developed under the concept of making them (JP-A-11-128736 and JP-A-2000-51654). The reason why copper-manganese complex oxide or iron-manganese complex oxide is used for the support is that NO is oxidized to NO ₂ on the support surface by the oxidizing power of manganese oxide and changed to a form that is easy to be adsorbed. This is because the catalytic action of copper or iron is utilized so that manganese oxide returns to its original oxidation state by reaction with oxygen in the air. On the other hand, this reaction causes all NO _X to be in the form of NO _{2 in} the vicinity of the support surface, but immediately adsorbs chemically and strongly to the ruthenium compound present on the support, or reacts with moisture to react with nitric acid or nitrous acid. It is adsorbed on the carrier or ruthenium compound in the form of nitric acid. Compared to ordinary adsorbents, NO adsorption affinity is overwhelmingly high, and it can be said that these series of adsorption reactions are all excellent in that they proceed at room temperature.

In addition, when the moisture content of the gas is very low, such as when the moisture dew point of the gas is −20 ° C. or less, the adsorbent is not required to support ruthenium on the copper-manganese composite oxide or iron-manganese composite oxide. In this case, ruthenium does not have to be contained because it is firmly fixed as NO ₂ or the like. That is, an adsorbent composed of one or more of a copper-manganese composite oxide and an iron-manganese composite oxide can be used.

As NO _X adsorbent in the present invention, the use of adsorbents having such a function, NO _X in the conventional of the NO _X analysis techniques could not be determined low concentration region can be monitored more reliably, more reliability High measurement is possible.

But are as described above adsorption mechanism of the adsorbent, manganese oxide by oxidizing the NO to NO ₂ is for receiving a reducing, oxidizing power manganese gradually decreases. Gas as an object of monitoring in the present invention (raw material gas) is normally so if lean of the NO _X concentration is large, it is rare to adsorb to manganese lose their oxidizing power. However, by gradually oxidizing power is reduced, when there is a concern that the total amount acquisition of the NO _X can not be guaranteed, it is possible to use without reducing the oxidizing power of manganese by compensating oxygen from the outside . At this time, oxygen is usually supplemented by mixing an oxygen-containing gas such as air with the raw material gas. What is necessary is just to make oxygen concentration in the gas after mixing more than 0 vol% and 20 vol% or less [9th invention]. Normally, about 1 vol% is sufficient for this oxygen concentration. Even if this oxygen concentration exceeds 20 vol%, the effect is not saturated, but there is no point in actively adding oxygen at a concentration exceeding the oxygen concentration in the air. However, when adopting an operation in which oxygen is supplemented from the outside during the adsorption, it is not preferable in terms of safety to return the adsorption tower outlet gas to the process introduction line. When recycling the adsorbent, the oxidizing power of manganese is restored to the initial performance when heated in the presence of oxygen. When NO _X analysis after adsorption, when employing the thermal desorption method, a gas containing oxygen, usually to play with air can be carried out simultaneously oxidizing power regeneration of manganese oxide.

  In order to mix the oxygen-containing gas into the raw material gas, a means for mixing the oxygen-containing gas with the raw material gas introduced into the adsorption tower and a means for adjusting the amount of the oxygen-containing gas to be mixed are prepared. [5th invention]. Then, mixing of the oxygen-containing gas into the raw material gas can be performed accurately and easily.

When the target raw material gas contains components that are susceptible to oxidation at high concentrations, for example, when hydrocarbon-based gas is the main component, hydrocarbon oxidation with manganese oxide is superior to NO. Therefore, oxidation of NO may be inhibited, and trapping of the entire amount of NO _X may not be guaranteed. In that case, it can be coped with by a method of combusting hydrocarbons by supplementing gas containing oxygen from the outside and introducing the exhaust gas into the monitor (adsorption tower) according to the present invention. It is sufficient that the oxygen concentration necessary for combustion is 3 vol% or more. When the gas supplemented from the outside is air, NO _x is generated due to oxidation of nitrogen when the combustion temperature is high, so it is more preferable to use an oxygen-containing gas that does not contain nitrogen. In introducing the oxygen-containing gas, it is preferable to use a means for adjusting the amount of the oxygen-containing gas mixed with the means for mixing the oxygen-containing gas, and the oxygen-containing gas can be introduced accurately and easily. . However, also in this case, it is not preferable for safety to return the adsorption tower outlet gas to the process introduction line.

NO _X NO _X trapped in the adsorbent, for example, a method of wet extracting the NO _X adsorbent with an alkaline extract solution or the like, a thermal desorption gas is recovered by a method in which aeration alkaline ToOsamueki, Quantitative analysis. According to the aforementioned adsorption mechanism, NO _X trapped in the adsorbent is NO _2, nitric acid or nitrous acid. For example, when extracted with an alkaline extract such as sodium hydroxide solution or sodium carbonate solution or heated water, nitrate ions Or desorbed in solution in the form of nitrite ions. The present inventors have found that according to the method of extraction with an alkaline aqueous solution or boiling water, it was confirmed that the entire amount of the NO _X trapped in the adsorbent is extracted into solution.

NO _X NO _X trapped in the adsorbent can be also desorbed by heating. The present inventors investigated the desorption behavior of NO _X trapped by the adsorbent and found that heating at 650 ° C. or higher is preferable for desorption. Below this temperature, a part of the adsorbed NO _X can not know the exact amount of adsorption to remain on the adsorbent, it can be measured accurately adsorption amount for the total amount of the NO _X when heated above 650 ° C. to desorb . There is no particular upper limit to the heating temperature, but it is preferably 800 ° C. or lower in view of cost.

  Nitrate ions or nitrite ions recovered in an alkaline aqueous solution or the like by these techniques are quantified by a method such as ion chromatography.

Further, when NO _X is desorbed by heating, the desorbed NO _X can be directly measured. In that case, it discovered that the chemical analysis method represented by the Salzmann method etc. and the instrumental analysis method represented by the chemiluminescence method were applicable.

By the method as described above, the integrated amount of NO _X captured by adsorption for a predetermined time is quantified. Normally, the process is operated at a constant gas flow rate, so the integrated amount of NO _X accompanying the process is calculated from the gas flow rate at the process inlet and the distribution ratio of the gas flow that is partially extracted and introduced into the adsorption tower. it can. Concentration of NO _X process inlet, even at low concentrations that can not be measured by conventional analytical techniques, by setting longer the monitoring time, NO _X accumulated amount brought into the process can now be quantified.

The amount of accumulated NO _X contained in the raw material gas can be quantified by the method described above, but the amount of accumulated NO and NO ₂ contained in the gas can also be quantified. As described above, the carrier carrying the ruthenium compound (NO _X adsorbent carrying the ruthenium compound) strongly adsorbs NO ₂ , nitric acid, and nitrous acid, but NO does not adsorb. NO ₂ is known to form a nitrosyl complex with a ruthenium compound, and the adsorption form when NO ₂ is adsorbed to the ruthenium compound is presumed to form this nitrosyl complex. NO is not only easily adsorbed on the carrier, but also does not form such a complex and cannot be captured by a ruthenium compound. Utilizing this property, two types of adsorbents are packed by either using two stages in series or by dividing the adsorbent into two parts, the first and second stages, in the adsorption tower. Then, NO ₂ and NO can be separately quantified. In the first stage, a ruthenium compound is supported on a carrier having no oxidizing power, and in the second stage, a carrier composed of a copper-manganese composite oxide or an iron-manganese composite oxide is loaded with a ruthenium compound. is there. When a gas containing NO _X is introduced into the monitor (adsorption tower) according to the present invention, NO ₂ of NO _X first reacts with the ruthenium compound and chemically adsorbs in the previous stage, but NO passes without being adsorbed. Slip to the back. In the latter stage, NO is oxidized by the carrier to become NO ₂ and chemisorbed with the ruthenium compound. Front of the adsorbent to the captured NO _X, by trapped NO _X to be separately analyzed in subsequent adsorbent is NO ₂ is quantitatively from the preceding analysis, NO is quantified from the subsequent analysis The

  The following apparatus can be mentioned as an apparatus applied to the method of making the adsorption tower two stages in series. That is, in the hydrocarbon-containing gas processing apparatus according to the first aspect of the present invention, the adsorption tower includes a first adsorption tower in which an adsorbent in which a ruthenium compound is supported on a carrier made of a non-basic oxide, Extraction comprising a second adsorption tower filled with an adsorbent in which a ruthenium compound is supported on a carrier made of a composite oxide and / or iron-manganese composite oxide, and extracting a part of the raw material gas and introducing it into the adsorption tower After the source gas extracted by the gas supply means is introduced into the first adsorption tower, the first adsorption tower and the second adsorption tower are connected in series in the order of introduction into the second adsorption tower. There is [fourth invention]. Note that when the gas does not contain moisture, a copper-manganese composite oxide not supporting ruthenium or an iron-manganese composite oxide can also be applied. That is, an adsorbent composed of one or more of a copper-manganese composite oxide and an iron-manganese composite oxide can be used.

When monitoring the NO _X accumulated amount in the present invention, after adsorption operation end of a predetermined time, for the captured amount of NO _X analysis the NO _X adsorbent, or NO _X adsorbent is taken out from the adsorption tower, or heat the desorption mode Thus, the adsorption tower is stopped. Then, the adsorption operation is resumed again. Therefore, intermittent operation is performed. However, such intermittent operation is not preferable when the amount of NO _X brought into the process before the next monitoring starts becomes a problem. In such a case, as a method for continuous monitoring, a method of operating a plurality of adsorption towers alternately is adopted.

  FIG. 2 shows an example of an apparatus applied to the above-described continuous monitoring method. After performing the adsorption operation in the right adsorption tower, the adsorption tower is switched to the regeneration operation in the heat desorption mode, and at the same time, the adsorption operation is started in the left adsorption tower. The central adsorption tower is on standby. Then, after the adsorption operation in the left adsorption tower is completed, the adsorption operation is started in the central adsorption tower.

In the present invention, when NO _X removal means is provided, it can be provided in the olefin recovery means. That is, the olefin recovery means can include NO _X removal means.

  Examples of the present invention will be described below. The present invention is not limited to this embodiment, and can be implemented with appropriate modifications within a range that can be adapted to the gist of the present invention, all of which are within the technical scope of the present invention. include.

[Example 1]
What was obtained by impregnating a porous support (1/16 inch pellet) containing iron-manganese composite oxide as a main component with a ruthenium chloride aqueous solution so that the amount of ruthenium supported was 1% by mass (weight%) and then drying it. , Used as NO _X adsorbent.

The NO _X adsorbent was filled into a glass adsorption tube having a diameter of 12 mm so as to have a filling height of 100 mm. Note that the filling amount of the NO _X adsorbent is 7.9 g.

Nitrogen gas containing NO was supplied to the adsorption tube filled with the NO _X adsorbent at a gas flow rate of 500 Nml / min, and the NO _X concentration of the outlet gas of the adsorption tube was monitored with a NO _X meter (chemiluminescence method). As a result, when the NO concentration in the gas supplied to the adsorption tube is 50 ppm or 5 ppm, the NO _X analysis value at the adsorption tube outlet side when gas is passed through the adsorption tube for 60 minutes is the lower limit (0.1 It was confirmed that NO, which is said to be difficult to adsorb, could be completely captured. It was also understood that there was an adsorption capacity of 0.0085 mmol / g or more per unit weight of adsorbent (when the NO concentration in the supply gas was 50 ppm) and 0.00085 mmol / g or more (when the NO concentration in the supply gas was 5 ppm). The NO _X adsorbent had sufficient performance for use as a NO _X monitor.

[Example 2]
A porous body (1/16 inch pellet) mainly composed of iron-manganese composite oxide was used as the NO _X adsorbent.

The NO _X adsorbent was filled into a glass adsorption tube having a diameter of 12 mm so as to have a filling height of 100 mm. Note that the filling amount of the NO _X adsorbent is 7.8 g.

Nitrogen gas containing NO was supplied to the adsorption tube filled with the NO _X adsorbent at a gas flow rate of 500 Nml / min, and the NO _X concentration of the outlet gas of the adsorption tube was monitored with a NO _X meter (chemiluminescence method). As a result, when the NO concentration in the gas supplied to the adsorption tube is 50 ppm or 5 ppm, the NO _X analysis value at the adsorption tube outlet side when gas is passed through the adsorption tube for 60 minutes is the lower limit (0.1 It was confirmed that NO, which is said to be difficult to adsorb, could be completely captured. It was also understood that there was an adsorption capacity of 0.0083 mmol / g or more per unit weight of adsorbent (when the NO concentration in the supply gas was 50 ppm) and 0.00083 mmol / g or more (when the NO concentration in the supply gas was 5 ppm). The NO _X adsorbent had sufficient performance for use as a NO _X monitor.

Example 3
Nitrogen gas containing 50 ppm NO and 1% ethylene was supplied at a gas flow rate of 500 Nml / min to an adsorption tube filled with the same amount of NO _X adsorbent as in Example 1, and the exit gas of the adsorption tube the of the NO _X concentration was monitored with a NO _X meter (chemiluminescence method). Although gas was passed for 60 minutes, the NO _X analysis value at the adsorption tube outlet side was below the lower limit (0.1 ppm), and it was confirmed that NO could be completely captured.

After passing the gas for 60 minutes, remove the adsorbent from the adsorption tube and immerse it in 50 ml of an alkaline aqueous solution (1.8M Na ₂ CO ₃ , 1.7M NaHCO ₃ ), shake for 10 minutes, and perform this immersion / shaking operation. After changing the solution and repeating three times, the entire solution was collected (collected), and nitrate ions and nitrite ions contained in the solution were quantified by ion chromatography. 0.063mmol was recovered in the form of nitrate ion and nitrite ion against NO adsorption history amount 0.067mmol. This recovery rate is 94%, which is almost balanced. Therefore, it was found that the accumulated amount of NO could be quantified by measuring the amount of gas passed through the adsorption pipe and the amount of adsorbed NO.

Example 4
Nitrogen gas containing 50 ppm NO and 1% ethylene was supplied at a gas flow rate of 500 Nml / min to an adsorption tube filled with the same amount of NO _X adsorbent as in Example 1, and the adsorption tube outlet gas The NO _X concentration was monitored with a NO _X meter (chemiluminescence method). Although gas was passed through for 60 minutes, the NO _X analysis value at the outlet side of the adsorption tube was below the lower limit (0.1 ppm), and NO could be completely captured.

After passing the gas for 60 minutes (after completion of adsorption), air was supplied from the inlet of the adsorption tube at a rate of 50 ml / minute, and 500 ml of alkaline aqueous solution (1.8M Na ₂ CO ₃ , 1.7M NaHCO ₃ ) was added to the adsorption tube outlet gas. The aeration bottle was aerated, the adsorption tube was heated to 650 ° C., and desorption was performed for 120 minutes.

  The nitrate ions and nitrite ions contained in the alkaline aqueous solution after desorption and aeration were quantified by ion chromatography. When an adsorbent with no NO adsorption / desorption history was used, a phenomenon was observed in which only a material balance of 10-30% was observed. However, repeated adsorption / desorption operations gradually increased the adsorption / desorption balance, resulting in a NO adsorption history. About what exceeded 1.5 mmol / g per adsorbent unit weight, 0.065 mmol was recoverable with the form of nitrate ion and nitrite ion with respect to NO adsorption history amount 0.067 mmol. This recovery rate is 97%, which is almost balanced. Therefore, it was found that the accumulated amount of NO can be quantified according to the gas passing through the adsorption tube, the heat desorption operation, and the quantitative analysis.

Example 5
A tubular electric furnace (inner diameter 20mmφ, soaking zone 50mm) in which nitrogen gas 50Nml / min containing 500ppm NO and 20% ethylene was mixed with 450Nml / min 20% oxygen 80% argon mixed gas and maintained at 1200 ° C The gas passed through the soaking zone at a residence time of 2 seconds was supplied to the same adsorption tube as in Example 1, and the NO _x concentration of the adsorption tube outlet gas was monitored with a NO _x meter (chemiluminescence method). Although gas was passed through for 60 minutes, the NO _X analysis value at the outlet side of the adsorption tube was below the lower limit (0.1 ppm), and NO could be completely captured.

After passing the gas for 60 minutes, remove the adsorbent from the adsorption tube and immerse it in 50 ml of an alkaline aqueous solution (1.8M Na ₂ CO ₃ , 1.7M NaHCO ₃ ), shake for 10 minutes, and perform this immersion / shaking operation. After changing the solution and repeating three times, the entire solution was collected (collected), and nitrate ions and nitrite ions contained in the solution were quantified by ion chromatography. 0.066 mmol could be recovered in the form of nitrate ion and nitrite ion against 0.067 mmol NO adsorption history amount. This recovery rate is 99%, which is almost balanced. Therefore, according to the method described above, it was found that the accumulated amount of NO can be quantified.

Example 6
A porous support (1/16 inch pellet) mainly composed of alumina was impregnated with an aqueous ruthenium chloride solution so that the amount of ruthenium supported was 1% by weight and dried, and used as the NO _X adsorbent.

The NO _X adsorbent was filled into a glass adsorption tube having a diameter of 12 mm so as to have a filling height of 100 mm. Note that the filling amount of the NO _X adsorbent is 7.9 g.

The adsorption tube filled with the NO _X adsorbent is used in the preceding stage, and the same adsorption tube as in Example 1 (the amount of ruthenium supported on the porous carrier mainly composed of iron-manganese composite oxide is 1% by weight. In this way, nitrogen gas containing 1.5 ppm NO ₂ and 50 ppm NO is supplied at a gas flow rate of 500 Nml / min. the concentration of NO _X adsorption tube outlet gas was monitored by the NO _X meter (chemiluminescence method). At this time, gas was passed for 60 minutes. As a result, the NO _X analysis value at the outlet of the subsequent adsorption tube after passing through gas for 60 minutes was below the lower limit (0.1 ppm), and NO _X could be completely captured.

After passing the gas for 60 minutes, the adsorbent is taken out from the former adsorption tube, and the adsorbent is taken out from the latter adsorption tube, which is separately immersed in 50 ml of an alkaline aqueous solution (1.8 M Na ₂ CO ₃ , 1.7 M NaHCO ₃ ). Shake for 10 minutes and repeat this immersion / shaking operation three times with the solution changed. Then, collect (collect) the entire solution and ion chromatograph the nitrate and nitrite ions contained in the solution. Quantified graphically.

As a result, from the adsorbent of the adsorption tube in the former stage, 0.0019 mmol in the form of nitrate ion and nitrite ion is compared to the amount of NO ₂ adsorption history of 0.0020 mmol, and from the adsorbent in the latter stage of adsorption is 0.067 mmol. 0.062 mmol could be recovered in the form of nitrate ion and nitrite ion against the NO adsorption history amount. The recovery rates are 95% and 93%, respectively. Therefore, according to the above method, it was found that NO ₂ and NO can be separately quantified.

Example 7
A porous body (1/16 inch pellet) mainly composed of iron-manganese composite oxide was used as the NO _X adsorbent.

The NO _X adsorbent was filled into a glass adsorption tube having a diameter of 12 mm so as to have a filling height of 100 mm. Note that the filling amount of the NO _X adsorbent is 7.8 g.

Nitrogen gas containing NO: 50 ppm was supplied to the adsorption tube filled with the NO _x adsorbent at a gas flow rate of 500 Nml / min to adsorb NO _x . After adsorption of NO _X, the adsorbent was heated from room temperature to 700 ° C. over 3 hours, the adsorbed NO _X was desorbed, and the NO _X concentration was measured by chemiluminescence method to calculate the adsorbed NO _X amount. As a result, the supplied NO _X amount was 0.008 mmol / g per unit weight of the adsorbent, but the NO _X amount calculated from the desorbed NO _X was 0.0079 mmol / g, and heat desorption and chemiluminescence at 700 ° C. It was found that the amount of adsorption could be completely grasped by analysis by the method.

[Comparative Example 1 (Examination of applicability of Salzmann method)]
Dissolve 5 g of sulfanilic acid and 50 ml of glacial acetic acid in warm water, and add a solution of 0.05 g of N-1-naphthylethylenediamine dihydrochloride in 50 ml of water and water to make a total volume of 1000 ml. Prepared (stored in a brown bottle).

  0.2M potassium permanganate sulfate acid solution (sulfuric acid concentration 0.5N) 50ml of washing bottle and 50ml of absorption coloring solution 50ml were connected in series in this order, 50ppm NO and 1% ethylene. Nitrogen gas containing was aerated at a gas flow rate of 500 Nml / min for 30 minutes.

  Then, using a photoelectric photometer, the absorbance at a wavelength of 545 nm was measured to quantify the color forming component concentration. The concentration of the coloring component in the absorbing solution after aeration was quantified from a calibration curve prepared in advance by measuring the absorbance of the absorbing coloring solution to which a potassium nitrate aqueous solution having a known concentration was added.

As a result, only 0.039 mmol could be recovered with respect to the total NO _X amount 0.067 mmol in the gas passed through the absorbing solution.

[Examination example of influence of heat desorption conditions]
Nitrogen gas containing 50 ppm NO and 1% ethylene was supplied at a gas flow rate of 500 Nml / min to an adsorption tube filled with the same amount of NO _X adsorbent as in Example 1, and the exit gas of the adsorption tube the of the NO _X concentration was monitored with a NO _X meter (chemiluminescence method). Although gas was passed through for 60 minutes, the NO _X analysis value at the outlet side of the adsorption tube was below the lower limit (0.1 ppm), and NO could be completely captured.

After passing the gas for 60 minutes, air is supplied at 50 ml / min from the inlet of the adsorption tube, and the gas at the outlet of the adsorption tube is aerated in a washing bottle containing 500 ml of an alkaline aqueous solution (1.8M Na ₂ CO ₃ , 1.7M NaHCO ₃ ). The adsorption tube was heated to 140 ° C. and desorption was performed for 120 minutes.

The nitrate ions and nitrite ions contained in the alkaline aqueous solution after desorption and aeration were quantified by ion chromatography. Even when NO _X adsorbent with a NO adsorption history exceeding 1.5 mmol / g per unit weight of adsorbent was used as the NO _X adsorbent, nitrate and nitrite ions were used for 0.067 mmol of NO adsorption history. Only 0.026 mmol was recovered in form. This is because the heating temperature at the time of heat desorption was 140 ° C., and the degree of desorption was small. Therefore, when desorbing at 140 ° C, it is necessary to prepare a calibration curve for the desorption temperature and desorption rate in advance and calculate the total amount of adsorption based on this, and there may be problems in terms of accuracy. There is.

In the above embodiment uses a test apparatus was filled in a glass suction tube diameter 12mm the NO _X adsorbent as NO _X monitor, use those filled with NO _X adsorbent in the adsorption tower of the utility-scale Even if it is a case, it is possible to obtain the same effect as the case of the said Example.

  Further, in the above embodiment, the gas is directly introduced into the adsorption tube, but this is for confirming the effect of the present invention by a simple method, and the gas introduced into the adsorption tube is substantially It corresponds to the extracted gas.

The hydrocarbon-containing gas processing apparatus and method according to the present invention provides a hydrocarbon-containing gas such as FCC off-gas as a raw material gas to the olefin recovery means and recovers the olefin from the raw material gas. _{Since the} amount of _X can be determined, it can be suitably used as an apparatus and method for recovering olefin from a hydrocarbon-containing gas with a small amount of NO _X such as FCC offgas.

It is a schematic diagram which shows Embodiment 1 of the hydrocarbon containing gas processing technique which concerns on this invention. It is a schematic diagram which shows an example of the hydrocarbon containing gas processing apparatus which concerns on this invention.

Claims (13)

An adsorption tower having an olefin recovery means for recovering olefins from a raw material gas mainly composed of hydrocarbons, a raw material gas supply means for supplying the raw material gas to the olefin recovery means, and an NO _x adsorbent-filled adsorption tower; Extraction gas supply means for extracting a part of the gas and introducing it into the adsorption tower, measuring the amount of NO _X adsorbed on the NO _X adsorbent, and the measured NO _X amount and the source gas and characterized in that on the basis of the ratio of the raw material gas volume bled by the extracted gas supply means as a raw material gas amount supplied by the supply means, and configured to determine the amount of NO _X introduced into the olefin recovery means Hydrocarbon-containing gas treatment device. The NO _X adsorbent is obtained by supporting a ruthenium compound on a support composed of at least one selected from a copper-manganese composite oxide, an iron-manganese composite oxide, and a non-basic oxide. The hydrocarbon-containing gas treatment device according to 1. The hydrocarbon-containing gas treatment device according to claim 1, wherein the NO _X adsorbent is made of at least one selected from a copper-manganese composite oxide and an iron-manganese composite oxide.   A first adsorption tower in which the adsorption tower is filled with an adsorbent in which a ruthenium compound is supported on a carrier made of a non-basic oxide, and a carrier made of a copper-manganese composite oxide and / or an iron-manganese composite oxide. An adsorbent in which a ruthenium compound is supported, or a second adsorption tower filled with at least one adsorbent selected from a copper-manganese composite oxide and an iron-manganese composite oxide, and the extraction gas The first adsorption tower and the second adsorption tower are connected in series in the order in which the source gas extracted by the supply means is introduced into the first adsorption tower and then introduced into the second adsorption tower. The hydrocarbon containing gas processing apparatus in any one of -3.   The hydrocarbon-containing gas processing apparatus according to any one of claims 1 to 4, comprising means for mixing an oxygen-containing gas with a raw material gas introduced into the adsorption tower, and means for adjusting the amount of the oxygen-containing gas to be mixed. . Source gas hydrocarbon mainly composed of a hydrocarbon-containing gas treatment method for recovering olefins from feed to feed gas to olefins recovery means by the raw material gas supply means, the bleed to NO _X adsorbing a portion of the raw material gas agent is introduced into the adsorption tower filled, after adsorption of NO _X in the NO _X absorbent, the measure the adsorbed amount of NO _X, the raw material gas amount supplied by the raw material gas supply means A hydrocarbon-containing gas treatment method, wherein the amount of NO _x introduced into the olefin recovery means is determined based on a ratio to the amount of extracted raw material gas. 7. The NO _x adsorbent is obtained by supporting a ruthenium compound on a support composed of one or more of a copper-manganese composite oxide, an iron-manganese composite oxide, and a non-basic oxide. Hydrocarbon-containing gas treatment method. The hydrocarbon-containing gas treatment method according to claim 6, wherein the NO _X adsorbent comprises at least one of a copper-manganese composite oxide and an iron-manganese composite oxide.   Before or after introducing the extracted source gas into the adsorption tower, an oxygen-containing gas is mixed with the source gas so that the oxygen concentration in the mixed gas is more than 0 vol% and not more than 20 vol% Item 9. The hydrocarbon-containing gas treatment method according to any one of Items 6 to 8. The measurement of the NO _X NO _X amount adsorbed on the adsorbent, the after immersed in extracts NO _X adsorbent to extract the NO _X, measured nitrate ion and / or nitrite ions in the extract The hydrocarbon containing gas processing method in any one of Claims 6-9 performed by doing. After the adsorption of NO _X in the NO _X adsorbent filled in the adsorption tower, the adsorption tower to desorb the heated gas above 650 ° C., ToOsamueki the NO _X desorption gas resulting from this The amount of NO _x adsorbed on the NO _x adsorbent is measured by measuring the nitrate ion and / or nitrite ion in the solution. Hydrocarbon-containing gas treatment method. After NO _X is adsorbed on the NO _X adsorbent packed in the adsorption tower, the adsorption tower is heated to 650 ° C. or higher to desorb the gas, and the resulting NO _X in the desorbed gas is analyzed by chemical analysis. by measuring the hydrocarbon-containing gas treatment method according to any one of claims 6-9 for measuring the amount of NO _X adsorbed in the NO _X absorbent. After NO _X is adsorbed to the NO _X adsorbent packed in the adsorption tower, the adsorption tower is heated to 650 ° C. or higher to desorb the gas, and NO _X in the desorbed gas generated thereby is analyzed by instrumental analysis. by measuring the hydrocarbon-containing gas treatment method according to any one of claims 6-9 for measuring the amount of NO _X adsorbed in the NO _X absorbent.

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