JPH0585960A - Production of purified naphthalene - Google Patents
Production of purified naphthaleneInfo
- Publication number
- JPH0585960A JPH0585960A JP3249788A JP24978891A JPH0585960A JP H0585960 A JPH0585960 A JP H0585960A JP 3249788 A JP3249788 A JP 3249788A JP 24978891 A JP24978891 A JP 24978891A JP H0585960 A JPH0585960 A JP H0585960A
- Authority
- JP
- Japan
- Prior art keywords
- naphthalene
- purified
- crude
- pressure
- liquid phase
- 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.)
- Pending
Links
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は精製ナフタリンの製造方
法、より詳しくは粗ナフタリン（純度９０〜９８％）か
ら不純物を除去することにより高純度の精製ナフタリン
を製造する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing purified naphthalene, and more particularly to a method for producing highly purified purified naphthalene by removing impurities from crude naphthalene (purity 90 to 98%).
【０００２】[0002]
【従来技術とその問題点】高純度の精製ナフタリンは、
界面活性剤、防虫剤、染料中間物質、高機能プラスチッ
ク、医薬品等の原料として幅広く利用されている。上記
精製ナフタリンは一般にコールタールを蒸留して得られ
る粗ナフタリン（市販ナフタリン）から製造されるが、
この粗ナフタリンは硫黄分（約 4500 ppm）、塩基性窒
素分（約500ppm）、オレフィン類（約0.2%）等の多数の
不純物を含んでいる。[Prior Art and its Problems] High-purity purified naphthalene is
It is widely used as a raw material for surfactants, insect repellents, dye intermediates, high-performance plastics, and pharmaceuticals. The above-mentioned purified naphthalene is generally produced from crude naphthalene (commercial naphthalene) obtained by distilling coal tar.
This crude naphthalene contains many impurities such as sulfur (about 4500 ppm), basic nitrogen (about 500 ppm), and olefins (about 0.2%).
【０００３】このため、粗ナフタリンより精製ナフタリ
ンを製造するために粗ナフタリンから上記各種の不純物
を除去する方法が種々提案されている。例えば粗ナフタ
リンを高温高圧下で水素化精製した後、冷却固化し、圧
搾し、溶融して蒸留した後に白土処理を施すことにより
精製ナフタリンを得る方法がある。また、オレフィン、
キノリン等を除去する方法として冷却晶析法も知られて
いる。Therefore, various methods for removing the above-mentioned various impurities from crude naphthalene have been proposed in order to produce purified naphthalene from crude naphthalene. For example, there is a method of obtaining purified naphthalene by hydrorefining crude naphthalene under high temperature and high pressure, cooling and solidifying, pressing, melting, distilling, and then treating with clay. Also, olefins,
A cooling crystallization method is also known as a method for removing quinoline and the like.
【０００４】しかしながら、前者の方法では水素化精製
に於ける反応条件が厳しいために装置にかかる負担が大
きくなり、しかも副生成物として５〜１０％ものテトラ
リンがナフタリンから生成し、精製ナフタリンの歩留ま
りのロスが大きくなる。一方、後者の方法ではナフタリ
ン純度は９９％程度に向上できるものの、硫黄分が実質
的に除去されないという問題がある。However, in the former method, the reaction conditions in the hydrorefining are strict, so that the load on the apparatus becomes large, and 5 to 10% of tetralin is produced from naphthalene as a by-product, and the yield of the purified naphthalene is high. The loss will increase. On the other hand, although the latter method can improve the naphthalene purity to about 99%, it has a problem that the sulfur content is not substantially removed.
【０００５】[0005]
【問題点を解決するための手段】本発明は、粗ナフタリ
ンから不純物の除去を有効に行ないつつ、水素化精製工
程によるナフタリンの歩留りを高め、高収率で精製ナフ
タリン得る方法を提供することを目的とする。DISCLOSURE OF THE INVENTION The present invention provides a method for obtaining purified naphthalene in a high yield while effectively removing impurities from crude naphthalene and increasing the yield of naphthalene in the hydrorefining process. To aim.
【０００６】本発明者らは、上記問題を解決すべく鋭意
研究を重ねた結果、特定条件下の低圧乃至中圧液相水素
化を行ない、次いで酸洗浄し、白土処理した場合には上
記目的を達成できることを見出し、本発明を完成するに
至った。As a result of intensive studies to solve the above problems, the inventors of the present invention conducted low-pressure to medium-pressure liquid phase hydrogenation under specific conditions, followed by acid washing and treating with clay to obtain the above object. The inventors have found that the above can be achieved and have completed the present invention.
【０００７】即ち、本発明は、粗ナフタリンを、(1) 低
圧乃至中圧液相水素化精製、(2) 脱気、(3) 酸洗浄、
(4) 分離、(5) 脱水、(6) 白土処理、(7) 蒸留、(8) 圧
搾の各工程により順次処理することを特徴とする精製ナ
フタリンの製造方法に係るものである。[0007] That is, the present invention, crude naphthalene, (1) low pressure to medium pressure liquid phase hydrorefining, (2) degassing, (3) acid cleaning,
(4) Separation, (5) Dehydration, (6) Clay treatment, (7) Distillation, (8) Sequential treatment in each step of each step of the production of purified naphthalene.
【０００８】以下、本発明について詳細に説明する。The present invention will be described in detail below.
【０００９】本発明の出発原料として用いる粗ナフタリ
ンとしては、純度９０〜９８％程度の通常の粗ナフタリ
ンであれば特に限定されない。The crude naphthalene used as the starting material of the present invention is not particularly limited as long as it is a usual crude naphthalene having a purity of about 90 to 98%.
【００１０】まず上記粗ナフタリンの水素化を低圧乃至
中圧液相水素化精製工程により行なう。その反応条件と
しては、水素ガス気流下、反応温度１００〜３００℃程
度、反応圧力０〜２０kgf/cm2 程度、より好ましくは５
〜１０kgf/cm2 程度、流量比（水素／ナフタリン）５０
〜２０００（Ｎｍ3 ／ｍ3 ）、空塔速度０．５〜５（１
／ｈ）とし、触媒としてはコバルト−モリブデン触媒
（Ｃｏ，Ｍｏ／Ａｌ2Ｏ3 ）、ニッケル−モリブデン触
媒（Ｎｉ，Ｍｏ／Ａｌ2 Ｏ3 ）、白金−活性炭触媒（Ｐ
ｔ／Ｃ）、ニッケル−タングステン触媒（Ｎｉ，Ｗ／Ａ
ｌ2 Ｏ3 ）、Ｐｔ・Ｎｉ合金−モリブデン触媒（Ｐｔ−
Ｎｉ，Ｍｏ／Ａｌ2 Ｏ3 ）、パラジウム−アルミナ触媒
（Ｐｄ／Ａｌ2 Ｏ3 ）等の公知の各種触媒を用いること
ができる。First, the hydrogenation of the crude naphthalene is carried out by a low to medium pressure liquid phase hydrorefining process. The reaction conditions are, under a hydrogen gas stream, a reaction temperature of about 100 to 300 ° C., a reaction pressure of about 0 to 20 kgf / cm 2 , and more preferably 5
About 10kgf / cm 2 , flow rate ratio (hydrogen / naphthalene) 50
~ 2000 (Nm 3 / m 3 ), superficial velocity 0.5 to 5 (1
/ H), and as a catalyst, a cobalt-molybdenum catalyst (Co, Mo / Al 2 O 3 ), a nickel-molybdenum catalyst (Ni, Mo / Al 2 O 3 ), a platinum-activated carbon catalyst (P
t / C), nickel-tungsten catalyst (Ni, W / A
l 2 O 3), Pt · Ni alloy - molybdenum catalyst (Pt-
Various known catalysts such as Ni, Mo / Al 2 O 3 ) and palladium-alumina catalyst (Pd / Al 2 O 3 ) can be used.
【００１１】上記水素化精製で発生した硫化水素、アン
モニア、エチルベンゼン等を脱気工程により除去する。
脱気方法としては、溜めに静置して分離する方法、煮沸
による気液分離法等の公知の方法に従って行なえばよ
い。Hydrogen sulfide, ammonia, ethylbenzene and the like generated in the above hydrorefining are removed by a degassing step.
The degassing method may be carried out according to a known method such as a method of leaving it standing in a reservoir for separation or a gas-liquid separation method by boiling.
【００１２】次に残留した粗ナフタリンを酸性水溶液に
より酸洗浄を行ない、残留する塩基性窒素分を取り除
く。ここで用いる酸性水溶液としては、硫酸、塩酸等の
各種無機酸を用いることができる。その濃度は通常５〜
３０％とし、２５〜８５℃程度の温度下で処理を行な
い、その後エチルベンゼンと水との共沸蒸留によってナ
フタレン中の水分を除去する。Next, the remaining crude naphthalene is acid-washed with an acidic aqueous solution to remove the residual basic nitrogen content. As the acidic aqueous solution used here, various inorganic acids such as sulfuric acid and hydrochloric acid can be used. Its concentration is usually 5
The treatment is carried out at a temperature of about 25 to 85 ° C. at 30%, and then water in naphthalene is removed by azeotropic distillation of ethylbenzene and water.
【００１３】酸洗浄後、白土処理を行なうが、この処理
によりキノリン、イソキノリン等の残留する塩基性窒素
分等の微量不純物が取り除かれる。白土処理工程ではナ
フタリンとベンゾチオフェンとの２量化反応によって高
沸点化合物が生成されるので、次工程の蒸留においてベ
ンゾチオフェンの分離除去を容易に行なうことができ
る。白土処理で使用する白土としては、通常用いられる
白土のほかにシリカアルミナ等の固体酸を有するものが
使用できる。白土処理の条件は常圧下１００〜２００℃
程度で空塔速度は０．５〜５（１／ｈ）程度とする。After the acid cleaning, a clay treatment is carried out. This treatment removes trace impurities such as quinoline and isoquinoline, such as residual basic nitrogen. Since the high boiling point compound is produced by the dimerization reaction of naphthalene and benzothiophene in the clay treatment step, the benzothiophene can be easily separated and removed in the distillation in the next step. As the white clay used in the white clay treatment, in addition to the commonly used white clay, those having a solid acid such as silica-alumina can be used. Clay treatment conditions are 100-200 ℃ under normal pressure.
The superficial velocity is about 0.5 to 5 (1 / h).
【００１４】続いて、常法に従い蒸留を行ない、準精製
ナフタレンを得る。次にこれを圧搾することにより本発
明精製ナフタレンが得られる。上記圧搾はスクリュープ
レス等の装置により常法に従って行なうことができる。
一方、圧搾による残分（全体の３０％程度）は、再び原
料粗ナフタリンとして上記プロセスに供給すれば更に精
製ナフタリンの歩留りの向上を図ることができる。Then, distillation is carried out according to a conventional method to obtain semi-purified naphthalene. Next, this is squeezed to obtain the purified naphthalene of the present invention. The squeezing can be carried out by an ordinary method using a device such as a screw press.
On the other hand, if the residue (about 30% of the whole) by pressing is supplied to the above process as raw material crude naphthalene again, the yield of purified naphthalene can be further improved.
【００１５】[0015]
【発明の効果】本発明によれば以下のような優れた効果
が得られる。According to the present invention, the following excellent effects can be obtained.
【００１６】（１）水素化精製におけるテトラリン副生
率を２％以下に抑え、精製ナフタリンの歩留りを大幅に
向上することができる。また水素の消費量も比較的少量
で済ますことができる。(1) The yield of purified naphthalene can be greatly improved by suppressing the tetralin by-product rate in hydrorefining to 2% or less. Moreover, the consumption of hydrogen can be relatively small.
【００１７】（２）塩基性窒素分を水素化精製に引続く
酸洗浄により除去するため、固体吸着剤の使用量を低減
させることができる。(2) Since the basic nitrogen content is removed by acid cleaning subsequent to hydrorefining, the amount of solid adsorbent used can be reduced.
【００１８】（３）水添ナフタレンを水素化精製時に副
生するエチルベンゼンに溶かし、酸洗浄を行なうことが
でき、その際粗ナフタリンを酸洗浄する場合にはスラッ
ジの発生がない。(3) Hydrogenated naphthalene can be dissolved in ethylbenzene, which is a by-product during hydrorefining, to carry out acid washing, and sludge is not generated when crude naphthalene is acid washed.
【００１９】（４）製造工程中、固化溶融工程がなく、
プラントフロー上ナフタリンを一貫して液体として取り
扱えるので一連の流通系の操作が簡便に行なえる。(4) There is no solidifying and melting step in the manufacturing process,
Since naphthalene can be handled as a liquid consistently on the plant flow, a series of distribution system operations can be performed easily.
【００２０】（５）水素化精製における反応条件が比較
的穏やかであり、特に反応圧力が１０kgf/cm2 以下のと
きには装置にかける負担ひいては装置の設置コストを軽
減でき、しかも操業及び保持点検が容易となる。(5) The reaction conditions in hydrorefining are relatively mild, and especially when the reaction pressure is 10 kgf / cm 2 or less, the burden on the equipment and thus the installation cost of the equipment can be reduced, and the operation and maintenance inspection are easy. Becomes
【００２１】[0021]
【実施例】以下に実施例を示し、本発明の特徴とすると
ころをより一層明瞭にする。但し、本発明は実施例のみ
に限定されない。尚、実施例中の％はすべて重量％を示
す 。 実施例１EXAMPLES Examples will be shown below to further clarify the characteristics of the present invention. However, the present invention is not limited to the examples. In addition, all% in the examples indicate% by weight. Example 1
【００２２】[0022]
【表１】 [Table 1]
【００２３】原料として表１に示すような組成をもつ粗
ナフタリンを用い、図１に示すような工程に従い、まず
中圧液相水素化精製を行なった。反応条件は、水素ガス
気流下、反応温度２８０℃、反応圧力６kgf/cm2 程度、
流量比（水素／ナフタリン）１７２（Ｎｍ3 ／ｍ3 ）、
空塔速度２（１／ｈ）とし、触媒としてはコバルト−モ
リブデン触媒（Ｃｏ，Ｍｏ／Ａｌ2 Ｏ3 ）を用いた。こ
のとき発生した硫化水素、アンモニア、エチルベンゼン
等を脱気工程により除去した。A crude naphthalene having a composition shown in Table 1 was used as a raw material, and an intermediate pressure liquid phase hydrorefining was first carried out according to the steps shown in FIG. The reaction conditions are as follows: hydrogen gas flow, reaction temperature 280 ° C., reaction pressure 6 kgf / cm 2 .
Flow rate ratio (hydrogen / naphthalene) 172 (Nm 3 / m 3 ),
The superficial velocity was 2 (1 / h), and a cobalt-molybdenum catalyst (Co, Mo / Al 2 O 3 ) was used as a catalyst. Hydrogen sulfide, ammonia, ethylbenzene and the like generated at this time were removed by a degassing step.
【００２４】次に残留した粗ナフタリンを２０％硫酸水
溶液により６０℃にて酸洗浄を行ない、塩基性窒素分を
取り除いた。その後乾燥させた。Next, the residual crude naphthalene was washed with an acid in a 20% aqueous solution of sulfuric acid at 60 ° C. to remove the basic nitrogen component. It was then dried.
【００２５】乾燥後、常圧下１５０℃で空塔速度１（１
／ｈ）で白土処理を行なった。続いて、常法に従い蒸留
を行ない、準精製ナフタレンを得、次にこれをスクリュ
ープレスで圧搾することにより純度９９．９％の本発明
精製ナフタレンを得た。After drying, the superficial velocity 1 (1
/ H). Then, distillation was carried out according to a conventional method to obtain semi-purified naphthalene, which was then pressed with a screw press to obtain the purified naphthalene of the present invention having a purity of 99.9%.
【００２６】この一連の製造工程において、低圧液相水
素化精製、酸洗浄、乾燥、白土処理、蒸留及び圧搾の各
段階後でのナフタリン純度（％）、テトラリン分
（％）、硫黄分(ppm) 及び塩基性窒素分(ppm) の測定結
果を反応条件と共に表２に示す。In this series of production steps, naphthalene purity (%), tetralin content (%), sulfur content (ppm) after each step of low-pressure liquid phase hydrorefining, acid washing, drying, clay treatment, distillation and pressing. ) And basic nitrogen content (ppm) are shown in Table 2 together with the reaction conditions.
【００２７】[0027]
【表２】 [Table 2]
【００２８】実施例２ 反応条件を表３のようにした以外は実施例１と同様に精
製ナフタリンの製造を行ない、実施例１の同様に各成分
の測定を行なった。その測定結果も表３に示す。尚、低
圧乃至中圧液相水素化精製における触媒としてはコバル
ト−モリブデン触媒（Ｃｏ，Ｍｏ／Ａｌ2 Ｏ3 ）を使用
し、また酸洗浄には２０％塩酸水溶液を用いた。Example 2 Purified naphthalene was produced in the same manner as in Example 1 except that the reaction conditions were changed as shown in Table 3, and each component was measured in the same manner as in Example 1. The measurement results are also shown in Table 3. A cobalt-molybdenum catalyst (Co, Mo / Al 2 O 3 ) was used as a catalyst in the low- to medium-pressure liquid-phase hydrorefining, and a 20% hydrochloric acid aqueous solution was used for acid cleaning.
【００２９】[0029]
【表３】 [Table 3]
【００３０】以上の結果より、本発明製造方法では不純
物を有効に除去しつつ、ナフタリン純度を９９．９％に
まで向上できることがわかる。From the above results, it is understood that the production method of the present invention can improve the purity of naphthalene to 99.9% while effectively removing impurities.
【図１】本発明の精製ナフタリンの製造方法における製
造フローの一例である。FIG. 1 is an example of a production flow in a method for producing purified naphthalene according to the present invention.
１…水添反応塔 ２…気液分離器 ３…中和槽 ４…静置分離槽 ５…脱水塔 ６…白土塔 ７…蒸留塔 ８…スクリュープレス ９…ヒーター 10…保圧弁 11…排ガス管 12…抜き出し管 13…給水管 14…排水管 1 ... Hydrogenation reaction tower 2 ... Gas-liquid separator 3 ... Neutralization tank 4 ... Stationary separation tank 5 ... Dehydration tower 6 ... White clay tower 7 ... Distillation tower 8 ... Screw press 9 ... Heater 10 ... Pressure holding valve 11 ... Exhaust gas pipe 12 ... Extraction pipe 13 ... Water supply pipe 14 ... Drainage pipe
フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｃ０７Ｃ 7/17 (72)発明者 佐藤 富徳 大阪府大阪市中央区平野町四丁目１番２号 大阪瓦斯株式会社内Continuation of front page (51) Int.Cl. 5 Identification number Internal reference number FI Technical indication C07C 7/17 (72) Inventor Futonori Sato 4-1-2 Hirano-cho, Chuo-ku, Osaka-shi, Osaka Osaka Gas Co., Ltd. In the company
Claims (3)
素化精製、(2) 脱気、(3) 酸洗浄、(4) 分離、(5) 脱
水、(6) 白土処理、(7) 蒸留、(8) 圧搾の各工程により
順次処理することを特徴とする精製ナフタリンの製造方
法。1. Crude naphthalene is subjected to (1) low pressure to medium pressure liquid phase hydrorefining, (2) degassing, (3) acid washing, (4) separation, (5) dehydration, (6) white clay treatment, (7) A method for producing purified naphthalene, which is characterized in that the steps are sequentially performed in each step of (7) distillation and (8) compression.
素化精製、(2) 脱気、(3) 酸洗浄、(4) 分離、(5) 脱
水、(6) 白土処理、(7) 蒸留の各工程により順次処理す
ることを特徴とする準精製ナフタリンの製造方法。2. Crude naphthalene is subjected to (1) low pressure to medium pressure liquid phase hydrorefining, (2) degassing, (3) acid cleaning, (4) separation, (5) dehydration, (6) clay treatment, (7) A method for producing semi-purified naphthalene, which comprises sequentially treating each step of distillation.
用いる請求項１又は請求項２記載の製造方法。3. The production method according to claim 1, wherein the residue from the pressing step is used as crude naphthalene.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3249788A JPH0585960A (en) | 1991-09-27 | 1991-09-27 | Production of purified naphthalene |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3249788A JPH0585960A (en) | 1991-09-27 | 1991-09-27 | Production of purified naphthalene |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0585960A true JPH0585960A (en) | 1993-04-06 |
Family
ID=17198234
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3249788A Pending JPH0585960A (en) | 1991-09-27 | 1991-09-27 | Production of purified naphthalene |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0585960A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0854126A1 (en) * | 1997-01-20 | 1998-07-22 | Institut Français du Pétrole | Process for the purification of naphthalene by selective hydrotreatment followed by a separation |
| ES2130071A1 (en) * | 1997-05-06 | 1999-06-16 | Nalon Quimica Sa | Process for obtaining refined naphthalene |
| CN106699500A (en) * | 2015-11-12 | 2017-05-24 | 中国石油化工股份有限公司 | Production method of phthalic anhydride raw material |
-
1991
- 1991-09-27 JP JP3249788A patent/JPH0585960A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0854126A1 (en) * | 1997-01-20 | 1998-07-22 | Institut Français du Pétrole | Process for the purification of naphthalene by selective hydrotreatment followed by a separation |
| FR2758555A1 (en) * | 1997-01-20 | 1998-07-24 | Inst Francais Du Petrole | PROCESS FOR THE PURIFICATION OF NAPHTHALENE BY SELECTIVE HYDROTREATMENT FOLLOWED BY SEPARATION |
| US6217750B1 (en) | 1997-01-20 | 2001-04-17 | Institut Francais Du Petrole | Process for purifying naphthalene by selective hydrotreatment followed by separation |
| ES2130071A1 (en) * | 1997-05-06 | 1999-06-16 | Nalon Quimica Sa | Process for obtaining refined naphthalene |
| CN106699500A (en) * | 2015-11-12 | 2017-05-24 | 中国石油化工股份有限公司 | Production method of phthalic anhydride raw material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE2227071C2 (en) | Process for cleaning technical fuel and synthesis gases | |
| CN108251155B (en) | Preparation method of low-viscosity poly α -olefin synthetic oil | |
| CN109232232B (en) | Refining method of acrylic acid | |
| JP4340802B2 (en) | Method for treating C4 hydrocarbons containing butadiene and acetylenic compounds, comprising a distillation step and a selective hydrogenation step | |
| JPH0585960A (en) | Production of purified naphthalene | |
| KR100631251B1 (en) | Process to afford gamma butyrolactone and tetrahydrofuran | |
| JP5466942B2 (en) | Method for producing primary diamine | |
| JP4001861B2 (en) | Method for removing formic acid from aqueous solution | |
| CN1377869A (en) | Process for producing purified dicyclic amylic diene and 5-sub ethyl-2-norbornene | |
| US4098838A (en) | Process for obtaining sulfur free pure naphthalene from bituminous coal tar and thionaphthene as a by-product | |
| CN111087291B (en) | Ammoximation reaction polyol ketone separating and recovering Process for preparing cyclohexanone | |
| USRE23507E (en) | Method fob producing and refining | |
| CN114436944B (en) | Synthesis method of ibrutinib intermediate | |
| US2575556A (en) | Method for producing and refining ethyl alcohol | |
| Watson et al. | The Cativa Process for the Production of Acetic Acid | |
| US2213267A (en) | Recovery of acetylene-containing gases free from carbon black and hydrocyanic acid | |
| JP4348890B2 (en) | Method for purifying gamma-butyrolactone | |
| CN220714838U (en) | Piperidine purifying equipment | |
| CN115974649B (en) | Method for producing sec-octyl alcohol | |
| JPH03181440A (en) | Purification of acrylic acid by distillation | |
| US1680070A (en) | Purification of naphthalene | |
| JPS6254791A (en) | Treatment of coal tar | |
| JP4154897B2 (en) | Method for purifying gamma-butyrolactone | |
| JPS63246343A (en) | Purification of higher alcohol | |
| CN112723992A (en) | Process for preparing high-purity decanediol by side-line vacuum rectification |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| LAPS | Cancellation because of no payment of annual fees |