JPH05139710A - Production of nitrous oxide - Google Patents

Production of nitrous oxide

Info

Publication number
JPH05139710A
JPH05139710A JP30599791A JP30599791A JPH05139710A JP H05139710 A JPH05139710 A JP H05139710A JP 30599791 A JP30599791 A JP 30599791A JP 30599791 A JP30599791 A JP 30599791A JP H05139710 A JPH05139710 A JP H05139710A
Authority
JP
Japan
Prior art keywords
ammonia
nitrous oxide
oxygen
steam
reactor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP30599791A
Other languages
Japanese (ja)
Other versions
JP3174369B2 (en
Inventor
Kenji Fujiwara
謙二 藤原
Atsuhiko Hiai
淳彦 日合
Hiroshi Kato
寛 加藤
Nobutaka Ueda
宜孝 上田
Toshihiko Tatsumi
敏彦 巽
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsui Toatsu Chemicals Inc
Original Assignee
Mitsui Toatsu Chemicals Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsui Toatsu Chemicals Inc filed Critical Mitsui Toatsu Chemicals Inc
Priority to JP30599791A priority Critical patent/JP3174369B2/en
Publication of JPH05139710A publication Critical patent/JPH05139710A/en
Application granted granted Critical
Publication of JP3174369B2 publication Critical patent/JP3174369B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01BNON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B21/00Nitrogen; Compounds thereof
    • C01B21/20Nitrogen oxides; Oxyacids of nitrogen; Salts thereof
    • C01B21/22Nitrous oxide (N2O)

Abstract

PURPOSE:To attain substantially 100% rate of conversion of ammonia and to produce nitrous oxide without discharging ammonia or causing environmental pollution by oxidizing ammonia with oxygen in the presence of steam in a reactor, condensing the unreacted ammonia together with the steam and circulating the resulting aq. ammonia soln. to the reactor. CONSTITUTION:When steam, ammonia and oxygen are fed into a reaction zone and nitrous oxide is produced, the resulting gaseous reactional product contg. nitrous oxide is cooled to condense the unreacted ammonia and steam into an aq. ammonia soln. and this ammonia soln. is separated from the nitrous oxide and circulated to the reaction zone.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は亜酸化窒素の製造方法に
関する。詳しくは、アンモニアを水蒸気の存在化に酸素
で酸化して亜酸化窒素を製造する方法に関する。亜酸化
窒素は麻酔ガスやロケット燃料用支燃剤あるいは半導体
用として有用な化合物である。
TECHNICAL FIELD The present invention relates to a method for producing nitrous oxide. More specifically, it relates to a method for producing nitrous oxide by oxidizing ammonia with oxygen in the presence of water vapor. Nitrous oxide is a compound useful as an anesthetic gas, a combustion-supporting agent for rocket fuel, or a semiconductor.

【0002】[0002]

【従来の技術】従来、亜酸化窒の製造方法としては、
(1) アンモニア酸化法、(2) 硝酸アンモニウム分解法、
(3) スルファミン酸と硝酸との反応による方法等が知ら
れている。この内、アンモニア酸化法(1) は原料が安価
なアンモニアと酸素であり、また、高収率が得られるた
めに工業的には好ましい方法である。
2. Description of the Related Art Conventionally, as a method for producing nitrous oxide,
(1) Ammonia oxidation method, (2) Ammonium nitrate decomposition method,
(3) A method of reacting sulfamic acid with nitric acid is known. Of these, the ammonia oxidation method (1) is an industrially preferable method because the starting materials are inexpensive ammonia and oxygen and a high yield can be obtained.

【0003】この方法は酸素あるいは空気を使用して金
属酸化物触媒上でアンモニアを200〜500 ℃で酸化し、
亜酸化窒素を製造する方法であり、使用する触媒は劣化
することが知られている。この対策として、触媒の再生
方法が提案されている(特公昭30-1225 )。また、触媒
調製時の硝酸アンモニウムを完全に洗浄して劣化しにく
い実用的な触媒調製方法(工業化学雑誌、64、11、1879
(1961))等が知られている。
This method uses oxygen or air to oxidize ammonia on a metal oxide catalyst at 200 to 500 ° C.,
It is a method for producing nitrous oxide, and the catalyst used is known to deteriorate. As a countermeasure against this, a catalyst regeneration method has been proposed (Japanese Patent Publication Sho 30-1225). In addition, a practical catalyst preparation method that thoroughly cleans ammonium nitrate during catalyst preparation to prevent deterioration (Industrial Chemistry Magazine, 64, 11, 1879)
(1961)) are known.

【0004】反応はアンモニア―酸素あるいはアンモニ
ア―酸素混合ガス(空気等)の爆発領域を避けるために
アンモニアの濃度が10 vol%以下になるように酸素ある
いは窒素で希釈して反応が行われる。この結果、80〜90
%の収率が得られるが、反応器出口の亜酸化窒素濃度は
数%にすぎない。さらに酸素を80vol %以上使用し、そ
の反応生成ガスを循環し、アンモニアだけを分割供給す
る方法(特公昭46-33210)が提案されているが、この場
合における亜酸化窒素濃度も40vol %程度が得られてい
るにすぎない(触媒:酸化マンガン+酸化ビスマス(Mn
2O3-Bi2O3))。この反応生成ガスは20Kg/cm2程度の高圧
下において亜酸化窒素を水に溶解し、さらに常圧下に放
出してより高濃度の亜酸化窒素を取り出す方法で濃縮さ
れる。この濃縮操作を繰り返すことにより亜酸化窒素を
さらに濃縮する。
The reaction is carried out by diluting it with oxygen or nitrogen so that the concentration of ammonia is 10 vol% or less in order to avoid an explosive region of ammonia-oxygen or an ammonia-oxygen mixed gas (air etc.). As a result, 80-90
% Yields are obtained, but the nitrous oxide concentration at the reactor outlet is only a few%. Furthermore, a method has been proposed in which oxygen is used at 80 vol% or more, the reaction product gas is circulated, and only ammonia is dividedly supplied (Japanese Patent Publication No. 46-33210), but in this case the nitrous oxide concentration is about 40 vol%. Only obtained (catalyst: manganese oxide + bismuth oxide (Mn
2 O 3 -Bi 2 O 3 )). This reaction-produced gas is concentrated by a method in which nitrous oxide is dissolved in water under a high pressure of about 20 kg / cm 2 and then released under normal pressure to take out a higher concentration of nitrous oxide. Nitrous oxide is further concentrated by repeating this concentration operation.

【0005】また、同公報2頁3欄6〜11行目には水蒸
気が「露点以下の温度では触媒に対し、一時的毒作用を
働き触媒の機能を低下させる」との記載があるだけで、
水の反応への影響については全く知られていない。
[0005] In addition, there is only a description in page 2, column 3, lines 6 to 11 of the publication that water vapor "temporarily poisons the catalyst at a temperature below the dew point and reduces the function of the catalyst." ,
Nothing is known about the effect of water on the reaction.

【0006】本発明者らは既に水蒸気を共存させてアン
モニアを酸化する方法を提案している。この方法では
(1)活性の劣化がないこと、 (2)水蒸気を水に凝縮する
だけで80%以上の高濃度の亜酸化窒素を得る事ができる
事、 (3)酸素あるいは窒素で爆発限界を避ける方法に比
べ安全領域が大きく、より安全に運転できること、 (4)
熱容量が窒素や酸素よりも大きいため反応の温度制御が
容易なこと、等の長所を有する。
The present inventors have already proposed a method of oxidizing ammonia by allowing water vapor to coexist. in this way
(1) No deterioration of activity, (2) It is possible to obtain high concentration of nitrous oxide of 80% or more just by condensing water vapor into water, (3) Method of avoiding explosion limit with oxygen or nitrogen The safety area is larger than that of, and it is possible to drive more safely, (4)
Since the heat capacity is larger than that of nitrogen or oxygen, it is easy to control the reaction temperature, and so on.

【0007】しかし、この方法においても、反応器容積
(触媒)あたりの原料の供給量を増すと反応器容積あた
りの亜酸化窒素の収量は増加するが、アンモニアの転化
率が低下し、未反応のアンモニアを処理する必要が生じ
る。したがって、従来の通常の方法ではアンモニアの転
化率が100 %になるように原料供給量を抑制して反応を
行う方法が一般的である。たとえば、特公昭46-33210の
実施例における空間速度は1,000 〜1,500 である。
However, even in this method, when the feed amount of the raw material per reactor volume (catalyst) is increased, the yield of nitrous oxide per reactor volume is increased, but the conversion rate of ammonia is decreased and unreacted. Ammonia needs to be treated. Therefore, in the conventional ordinary method, it is general to carry out the reaction by suppressing the feed amount of the raw material so that the conversion rate of ammonia becomes 100%. For example, the space velocity in the embodiment of JP-B-46-33210 is 1,000 to 1,500.

【0008】[0008]

【発明が解決しようとする課題】水の存在下、アンモニ
アを酸化する方法において、実質的にアンモニア転化率
を100 %にしてアンモニアの廃棄がない無公害の亜酸化
窒素を製造する方法を提供するものである。
PROBLEM TO BE SOLVED: To provide a method for producing pollution-free nitrous oxide which does not waste ammonia by substantially converting the ammonia conversion rate to 100% in the method of oxidizing ammonia in the presence of water. It is a thing.

【0009】[0009]

【課題を解決するための手段】本発明者らはアンモニア
酸化法において、水蒸気の存在下においてアンモニアを
酸素で酸化し、未反応のアンモニアを水蒸気と共に凝縮
して得たアンモニア水を反応器へ供給することにより、
反応に悪影響を与える事なく、むしろ、触媒の劣化を抑
制し、実質上、アンモニアの転化率が100 %になること
を見い出し本発明を完成した。
In the ammonia oxidation method, the present inventors supply ammonia water obtained by oxidizing ammonia with oxygen in the presence of water vapor and condensing unreacted ammonia together with water vapor to a reactor. By doing
The present invention has been completed by finding that the deterioration of the catalyst is suppressed without adversely affecting the reaction and the conversion of ammonia is substantially 100%.

【0010】すなわち、本発明は水蒸気、アンモニアお
よび酸素を反応帯へ供給して亜酸化窒素を製造する方法
において、得られた亜酸化窒素含有反応生成ガスを冷却
し、亜酸化窒素と未反応のアンモニアおよび水蒸気をア
ンモニア水として凝縮分離し、該アンモニア水を反応帯
へ循環することを特徴とする亜酸化窒素の製造方法であ
る。
That is, according to the present invention, in a method for producing nitrous oxide by supplying steam, ammonia and oxygen to a reaction zone, the obtained nitrous oxide-containing reaction product gas is cooled so as not to react with nitrous oxide. A method for producing nitrous oxide, characterized in that ammonia and water vapor are condensed and separated as ammonia water, and the ammonia water is circulated to the reaction zone.

【0011】本発明で使用する触媒は、アンモニア酸化
用触媒として知られている公知の触媒を使用することが
できる。驚くべきことに、水を添加すると、今まで触媒
の劣化が認められた触媒においても、その劣化はないか
あるいは極めて少ない。おそらく触媒上の硝酸痕のよう
な被毒物質の洗浄効果あるいは触媒の酸化状態の保持効
果のためと推測される。このような触媒の例としては、
CuO-MnO2系、Bi2O3 系、Fe2O3-Bi2O3-MnO2系、MnO-CoO-
NiO 系、Ba2O-CuO系、MnO2系、Pr2O3-Nd2O3-CeO3系、Pt
系が挙げられる。この中でもMn含有触媒が高活性であり
好ましい。さらに調製が容易なCuO-MnO2系が特に好まし
い。
As the catalyst used in the present invention, a known catalyst known as a catalyst for ammonia oxidation can be used. Surprisingly, when water is added, the deterioration of the catalyst, which has been observed so far, does not occur or is extremely small. Probably because of the cleaning effect of poisonous substances such as nitric acid traces on the catalyst or the effect of maintaining the oxidation state of the catalyst. Examples of such catalysts include:
CuO-MnO 2 system, Bi 2 O 3 system, Fe 2 O 3 -Bi 2 O 3 -MnO 2 system, MnO-CoO-
NiO system, Ba 2 O-CuO system, MnO 2 system, Pr 2 O 3 -Nd 2 O 3 -CeO 3 system, Pt
System. Among these, Mn-containing catalysts are preferable because they have high activity. Furthermore, the CuO-MnO 2 system, which is easy to prepare, is particularly preferable.

【0012】これらの触媒は通常管型反応器へ充填さ
れ、アンモニア、酸素および水蒸気等の混合ガスは0
℃、1気圧の状態に換算して空間速度100 〜100,000
(1/hr)、好ましくは1,000 〜50,000(1/hr)で供給され
る。
These catalysts are usually packed in a tubular reactor, and the mixed gas of ammonia, oxygen and steam is 0.
Space velocity 100 to 100,000 converted to 1 ℃
(1 / hr), preferably 1,000 to 50,000 (1 / hr).

【0013】本発明で重要なのは、水蒸気の存在下にア
ンモニアを酸素で酸化反応せしめた反応生成ガスを凝縮
して得られたアンモニア水を反応帯域に循環使用するこ
とにある。
What is important in the present invention is that the aqueous ammonia obtained by condensing the reaction product gas obtained by oxidizing ammonia with oxygen in the presence of water vapor is recycled to the reaction zone.

【0014】本発明者らの行った条件下ではアンモニア
―酸素―水蒸気系では水蒸気が約60%以上であればアン
モニア、酸素のモル比によらず爆発しないことがわかっ
た。反応器入り口組成において、50vol %以上の水蒸気
濃度があれば触媒の活性劣化に対する効果が大きい。し
かし、水蒸気が60vol %未満であれば、アンモニアの爆
発領域を避けるために酸素あるいは窒素で希釈して反応
ガス中のアンモニア濃度を10vol %以下にすることが望
ましい。
Under the conditions carried out by the present inventors, it was found that in the ammonia-oxygen-steam system, explosion does not occur irrespective of the molar ratio of ammonia and oxygen when the steam content is about 60% or more. If the water vapor concentration is 50 vol% or more in the reactor inlet composition, the effect on the catalyst activity deterioration is great. However, if the water vapor content is less than 60 vol%, it is desirable to dilute it with oxygen or nitrogen so that the ammonia concentration in the reaction gas is 10 vol% or less in order to avoid the explosion region of ammonia.

【0015】したがって、これらの余分な酸素あるいは
窒素を亜酸化窒素と分離する必要がある。一方、水蒸気
が反応器入り口において60vol %以上であればこのよう
な余分な酸素や窒素は必要がなく、直接、高濃度の亜酸
化窒素を分離することができる。したがって、好ましい
水蒸気の使用量は反応器入り口濃度で50vol %以上、さ
らに好ましくは60vol %以上である。
Therefore, it is necessary to separate these excess oxygen or nitrogen from nitrous oxide. On the other hand, if steam is 60 vol% or more at the inlet of the reactor, such extra oxygen and nitrogen are not necessary, and high-concentration nitrous oxide can be directly separated. Therefore, the preferable amount of steam used is 50 vol% or more, more preferably 60 vol% or more, at the concentration at the inlet of the reactor.

【0016】本発明の方法で使用するアンモニアは純粋
なアンモニアを使用してもよいが、アンモニア水溶液も
使用する事ができる。アンモニアの反応器入り口の濃度
は爆発領域を避けるために10vol %以下が好ましいが、
水蒸気の使用量が60vol %以上の場合にはその制限はな
く、循環するアンモニアおよび新たに供給するアンモニ
アの合計の濃度は反応器入り口において1〜30vol %の
範囲であり、好ましくは1〜20vol %の範囲である。
The ammonia used in the method of the present invention may be pure ammonia, but an aqueous ammonia solution can also be used. The concentration of ammonia at the inlet of the reactor is preferably 10 vol% or less in order to avoid the explosion area.
There is no limitation when the amount of steam used is 60 vol% or more, and the total concentration of circulating ammonia and newly supplied ammonia is in the range of 1 to 30 vol% at the reactor inlet, preferably 1 to 20 vol%. The range is.

【0017】本発明で使用する酸素は純粋な酸素も使用
することができるが、窒素を含んだ酸素を使用してもよ
い。空気は使用できるが、これ以上、窒素で希釈された
酸素を使用することは反応生成ガス中の亜酸化窒素濃度
が低くなり好ましくない。酸素の使用量はアンモニア1
モルに対し等モル以上が好ましい。
The oxygen used in the present invention may be pure oxygen, but oxygen containing nitrogen may be used. Although air can be used, it is not preferable to use oxygen diluted with nitrogen more than this because the nitrous oxide concentration in the reaction product gas becomes low. The amount of oxygen used is ammonia 1
It is preferably equimolar or more to the molar amount.

【0018】これらのアンモニア、酸素および水蒸気等
の混合ガスの供給速度は亜酸化窒素の選択率には影響を
与えない。しかし、小さすぎると反応器が大きくなって
不経済である。また、大きすぎるとアンモニアの転化率
が低下する。したがってこれらの混合ガスの供給速度
は、0℃、1気圧の状態に換算して空間速度 100〜100,
000(1/hr) の範囲、好ましくは 1,000〜50,000(1/hr)の
範囲である。
The feed rates of these mixed gases of ammonia, oxygen and water vapor do not affect the selectivity of nitrous oxide. However, if it is too small, the reactor becomes large and it is uneconomical. On the other hand, if it is too large, the conversion rate of ammonia decreases. Therefore, the supply rate of these mixed gases is converted into a state of 0 ° C. and 1 atm, and the space velocity is 100 to 100,
It is in the range of 000 (1 / hr), preferably in the range of 1,000 to 50,000 (1 / hr).

【0019】反応温度は200 〜500 ℃が好ましく、さら
に好ましくは250 〜450 ℃である。500 ℃より高くなる
と窒素酸化物の副生量が増加し好ましくない。
The reaction temperature is preferably 200 to 500 ° C, more preferably 250 to 450 ° C. If the temperature is higher than 500 ° C, the amount of nitrogen oxide by-product is increased, which is not preferable.

【0020】反応圧力は高圧の方が反応速度が早くなる
が、反応器が高価になり不経済であり、好ましくは0〜
20Kg/cm2-G、更に好ましくは0.3 〜5Kg/cm2-Gである。
The reaction pressure is higher when the reaction pressure is higher, but the reactor is expensive and uneconomical.
20Kg / cm 2 -G, more preferably from 0.3 ~5Kg / cm 2 -G.

【0021】このようにして反応を行った反応生成ガス
は250 〜450 ℃から、たとえば0〜80℃の水蒸気の沸点
以下に冷却され、水蒸気と亜酸化窒素、酸素、窒素等の
非凝縮性ガスに分離される。この時、未反応のアンモニ
アは水蒸気と共に凝縮され、通常、アンモニア濃度とし
て0.01〜5wt%の範囲で回収される。このアンモニア水
は必要に応じて一部をパージし、残りは反応器へ循環さ
れる。アンモニア水の一部をパージしてもよいが、アン
モニア水を加熱し、アンモニアの大部分を気化させ、残
った水から、反応で生成する水をパージする方法が好ま
しい。
The reaction product gas obtained by the reaction in this manner is cooled from 250 to 450 ° C. to a boiling point of steam of 0 to 80 ° C. or less, for example, and steam and non-condensable gases such as nitrous oxide, oxygen and nitrogen. Is separated into At this time, unreacted ammonia is condensed with water vapor, and is usually recovered in the range of 0.01 to 5 wt% as the ammonia concentration. A part of this ammonia water is purged, and the rest is circulated to the reactor. A part of the ammonia water may be purged, but a method of heating the ammonia water to vaporize most of the ammonia and purging the water produced by the reaction from the remaining water is preferable.

【0022】この結果、アンモニアの転化率は実質的に
100 %となる。また、アンモニア水の循環において、高
温の反応ガスで直接、あるいは、反応ガスの除熱に使用
したスチィームあるいは熱媒で間接的に100 〜300 ℃に
熱交換された後、反応器へ循環されることが好ましい。
当然、これらは上述のパージを行う場合のアンモニア水
の熱源として利用できる。
As a result, the conversion rate of ammonia is substantially
It will be 100%. Further, in the circulation of ammonia water, heat is directly exchanged with a high temperature reaction gas or indirectly with a steam or a heat medium used for heat removal of the reaction gas to 100 to 300 ° C, and then circulated to a reactor. Preferably.
Of course, these can be used as a heat source of ammonia water when the above-mentioned purging is performed.

【0023】一方、アンモニア水と分離された亜酸化窒
素は、さらに精製工程を経て、微量の窒素酸化物が除去
され、さらに、酸素、窒素が分離されて高純度の亜酸化
窒素が製造される。
On the other hand, the nitrous oxide separated from the ammonia water is further purified to remove a trace amount of nitrogen oxides, and further oxygen and nitrogen are separated to produce high-purity nitrous oxide. ..

【0024】[0024]

【実施例】以下、本発明を実施例により詳細に説明す
る。
EXAMPLES The present invention will be described in detail below with reference to examples.

【0025】実施例1 CuO ・ MnO2触媒(東洋CCI社製市販品)500 gを充填
した内径2.8cm の管型反応器へ、後述する0.6 wt%アン
モニア水、100 %アンモニアおよび酸素を反応器へ供給
した。反応器の入り口組成はアンモニア5vol %、酸素
5.3vol%、水蒸気89.7vol %であった。空間速度7,500
(1/hr)、反応圧力0.5Kg/cm2-G 、出口温度300 ℃で反応
を行った。反応器出口の反応生成ガスを30℃に冷却し、
液相のアンモニア水(0.5wt %)を常圧下、スチームで
加熱し、その重量の85%を気化させ、さらにその気相部
(0.6wt%に相当)をスチームで230℃まで予熱して反応
器へ循環した。
Example 1 To a tubular reactor having an inner diameter of 2.8 cm filled with 500 g of CuO.MnO 2 catalyst (commercially available from Toyo CCI), 0.6 wt% aqueous ammonia, 100% ammonia and oxygen, which will be described later, are added to the reactor. Supplied to. The composition of the reactor inlet is 5 vol% ammonia and oxygen.
It was 5.3 vol% and water vapor was 89.7 vol%. Space velocity 7,500
(1 / hr), the reaction pressure was 0.5 Kg / cm 2 -G, and the outlet temperature was 300 ° C. The reaction product gas at the outlet of the reactor is cooled to 30 ° C.,
Liquid phase ammonia water (0.5 wt%) is heated with steam under normal pressure to vaporize 85% of its weight, and the vapor phase part (corresponding to 0.6 wt%) is preheated to 230 ° C with steam to react. Circulated to the vessel.

【0026】その気相部を分析した結果、亜酸化窒素7
1.2vol %、窒素12.6vo%、酸素 16.2vol%であり、ア
ンモニアは痕跡量であった。この反応成績はアンモニア
の転化率92%、また、亜酸化窒素の収率85%に相当す
る。運転を3カ月にわたり継続した結果、15日目でアン
モニア転化率は90%、亜酸化窒素の選択率は86%となっ
たが、それ以降は変化しなかった。アンモニアの利用率
は99%以上である。この反応生成ガスを過マンガン酸カ
リウムを含むアルカリ水溶液に通して窒素酸化物を除去
し、さらに、20Kg/cm2-G、約−40℃で冷却して亜酸化窒
素を液化させ、酸素および窒素と分離した。このように
して得られた亜酸化窒素の純度は99%以上であり、満足
すべき品質であった。
As a result of analyzing the gas phase portion, nitrous oxide 7
The amount was 1.2 vol%, nitrogen was 12.6 vo%, oxygen was 16.2 vol%, and ammonia was a trace amount. The reaction results correspond to an ammonia conversion of 92% and a nitrous oxide yield of 85%. As a result of continuing the operation for 3 months, the ammonia conversion rate was 90% and the nitrous oxide selectivity was 86% on the 15th day, but it did not change thereafter. The utilization rate of ammonia is over 99%. This reaction product gas is passed through an aqueous alkaline solution containing potassium permanganate to remove nitrogen oxides, and further cooled at 20 Kg / cm 2 -G, about -40 ° C to liquefy nitrous oxide, and oxygen and nitrogen. And separated. The purity of the nitrous oxide thus obtained was 99% or more, which was a satisfactory quality.

【0027】実施例2 反応器入り口組成がアンモニア5vol%、酸素20vol %、
窒素20vol %、水蒸気55vol %となるようにアンモニア
水、100 %アンモニア、酸素を反応器へ供給した以外は
実施例1と同様の方法で反応を行った。その気相部を分
析した結果、亜酸化窒素 6.0vol %、窒素53.8vo%、酸
素40.2vol %であり、アンモニアは痕跡量であった。こ
れはアンモニアの転化率90%、亜酸化窒素の選択率85
%、アンモニア利用率99%以上に相当する。この運転を
1カ月にわたり継続した結果、アンモニア転化率90%、
選択率85%を維持した。
Example 2 The composition of the reactor inlet was 5 vol% ammonia, 20 vol% oxygen,
The reaction was carried out in the same manner as in Example 1 except that ammonia water, 100% ammonia and oxygen were supplied to the reactor so that the nitrogen content was 20 vol% and the water vapor content was 55 vol%. As a result of analyzing the gas phase portion, nitrous oxide was 6.0 vol%, nitrogen was 53.8 vo%, oxygen was 40.2 vol%, and ammonia was a trace amount. This is 90% conversion of ammonia and 85% nitrous oxide selectivity.
%, Equivalent to an ammonia utilization rate of 99% or more. As a result of continuing this operation for one month, the ammonia conversion rate was 90%,
The selectivity remained 85%.

【0028】比較例1 アンモニア水を循環しないで供給ガス組成が実施例1と
同じになるようにアンモニアを増やした以外は実施例1
と同様に反応を行った。アンモニア転化率は92%、亜酸
化窒素の選択率は85%であったが、0.5 wt%のアンモニ
ア水を廃棄する必要があった。
Comparative Example 1 Example 1 except that ammonia was increased so that the feed gas composition was the same as Example 1 without circulating ammonia water.
The reaction was performed in the same manner as in. The ammonia conversion rate was 92% and the nitrous oxide selectivity was 85%, but it was necessary to discard 0.5 wt% ammonia water.

【0029】比較例2 反応器の入口組成がアンモニア5vol %、酸素5.5vol
%、窒素89.5vol %になるように100 %アンモニア、酸
素および窒素を反応器へ供給し、アンモニア水を循環し
なかった以外は実施例1と同様の方法で反応を行った。
当初、アンモニアの転化率は90%、亜酸化窒素の選択率
85%であったが、3日目で活性の低下が認められ、1カ
月後には、アンモニア転化率は78%まで低下した。
Comparative Example 2 The composition of the reactor inlet was 5 vol% ammonia and 5.5 vol oxygen.
%, Nitrogen 100% ammonia, oxygen and nitrogen were supplied to the reactor so that the amount of nitrogen was 89.5 vol%, and the reaction was performed in the same manner as in Example 1 except that ammonia water was not circulated.
Initially, the conversion of ammonia was 90%, and the selectivity of nitrous oxide
Although it was 85%, a decrease in activity was observed on the third day, and the ammonia conversion rate decreased to 78% after one month.

【0030】[0030]

【発明の効果】アンモニア酸化法において、水蒸気を共
存させてアンモニアを酸化し、その反応ガスを凝縮して
得られたアンモニア水を反応器へ循環することにより、
触媒の劣化が抑制され、かつ、実質上アンモニア利用率
が100 %となり、アンモニアを廃棄することなく亜酸化
窒素を製造できる。
EFFECTS OF THE INVENTION In the ammonia oxidation method, ammonia is oxidized in the presence of water vapor, and the reaction gas is condensed to circulate ammonia water to a reactor.
Deterioration of the catalyst is suppressed, and the ammonia utilization rate is substantially 100%, and nitrous oxide can be produced without discarding ammonia.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 上田 宜孝 大阪府高石市高砂1丁目6番地三井東圧化 学株式会社内 (72)発明者 巽 敏彦 大阪府高石市高砂1丁目6番地三井東圧化 学株式会社内 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshitaka Ueda 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Chemicals Co., Ltd. (72) Toshihiko Tatsumi 1-6 Takasago, Takaishi-shi, Osaka Mitsui Toatsu Kagaku Co., Ltd.

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】水蒸気、アンモニアおよび酸素を反応帯へ
供給して亜酸化窒素を製造する方法において、得られた
亜酸化窒素含有反応生成ガスを冷却し、亜酸化窒素と未
反応のアンモニアおよび水蒸気をアンモニア水として凝
縮分離し、該アンモニア水を反応帯へ循環することを特
徴とする亜酸化窒素の製造方法。
1. A method for producing nitrous oxide by supplying steam, ammonia and oxygen to a reaction zone, wherein the obtained nitrous oxide-containing reaction product gas is cooled, and nitrous oxide and unreacted ammonia and steam are obtained. Is condensed and separated as ammonia water, and the ammonia water is circulated to the reaction zone, which is a method for producing nitrous oxide.
JP30599791A 1991-11-21 1991-11-21 Method for producing nitrous oxide Expired - Lifetime JP3174369B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP30599791A JP3174369B2 (en) 1991-11-21 1991-11-21 Method for producing nitrous oxide

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP30599791A JP3174369B2 (en) 1991-11-21 1991-11-21 Method for producing nitrous oxide

Publications (2)

Publication Number Publication Date
JPH05139710A true JPH05139710A (en) 1993-06-08
JP3174369B2 JP3174369B2 (en) 2001-06-11

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
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Country Status (1)

Country Link
JP (1) JP3174369B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5849257A (en) * 1996-04-03 1998-12-15 Mitsui Chemicals, Inc. Process for preparation of nitrous oxide

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5849257A (en) * 1996-04-03 1998-12-15 Mitsui Chemicals, Inc. Process for preparation of nitrous oxide

Also Published As

Publication number Publication date
JP3174369B2 (en) 2001-06-11

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