JPS6246533B2 - - Google Patents
Info
- Publication number
- JPS6246533B2 JPS6246533B2 JP56151149A JP15114981A JPS6246533B2 JP S6246533 B2 JPS6246533 B2 JP S6246533B2 JP 56151149 A JP56151149 A JP 56151149A JP 15114981 A JP15114981 A JP 15114981A JP S6246533 B2 JPS6246533 B2 JP S6246533B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- reactor
- parts
- acetic acid
- weight
- 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.)
- Expired
Links
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 claims description 139
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 78
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims description 70
- URLKBWYHVLBVBO-UHFFFAOYSA-N Para-Xylene Chemical group CC1=CC=C(C)C=C1 URLKBWYHVLBVBO-UHFFFAOYSA-N 0.000 claims description 42
- 239000007789 gas Substances 0.000 claims description 33
- 239000002994 raw material Substances 0.000 claims description 32
- 239000007788 liquid Substances 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 20
- 239000003054 catalyst Substances 0.000 claims description 18
- 239000002904 solvent Substances 0.000 claims description 14
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 11
- 238000007254 oxidation reaction Methods 0.000 claims description 11
- 229910001882 dioxygen Inorganic materials 0.000 claims description 10
- 238000003756 stirring Methods 0.000 claims description 10
- 239000012295 chemical reaction liquid Substances 0.000 claims description 7
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 claims description 6
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 claims description 6
- 229910052794 bromium Inorganic materials 0.000 claims description 6
- 239000010941 cobalt Substances 0.000 claims description 6
- 229910017052 cobalt Inorganic materials 0.000 claims description 6
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 6
- 239000011572 manganese Substances 0.000 claims description 6
- 230000003647 oxidation Effects 0.000 claims description 6
- 239000007791 liquid phase Substances 0.000 claims description 5
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 4
- 229910052748 manganese Inorganic materials 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 description 32
- 238000002485 combustion reaction Methods 0.000 description 19
- 230000000052 comparative effect Effects 0.000 description 14
- 239000000243 solution Substances 0.000 description 11
- 239000007795 chemical reaction product Substances 0.000 description 7
- 238000000605 extraction Methods 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- RVHSTXJKKZWWDQ-UHFFFAOYSA-N 1,1,1,2-tetrabromoethane Chemical compound BrCC(Br)(Br)Br RVHSTXJKKZWWDQ-UHFFFAOYSA-N 0.000 description 4
- ZBYYWKJVSFHYJL-UHFFFAOYSA-L cobalt(2+);diacetate;tetrahydrate Chemical compound O.O.O.O.[Co+2].CC([O-])=O.CC([O-])=O ZBYYWKJVSFHYJL-UHFFFAOYSA-L 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000008246 gaseous mixture Substances 0.000 description 4
- 229940082328 manganese acetate tetrahydrate Drugs 0.000 description 4
- CESXSDZNZGSWSP-UHFFFAOYSA-L manganese(2+);diacetate;tetrahydrate Chemical compound O.O.O.O.[Mn+2].CC([O-])=O.CC([O-])=O CESXSDZNZGSWSP-UHFFFAOYSA-L 0.000 description 4
- 238000006864 oxidative decomposition reaction Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000001590 oxidative effect Effects 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 238000010992 reflux Methods 0.000 description 3
- GOUHYARYYWKXHS-UHFFFAOYSA-N 4-formylbenzoic acid Chemical compound OC(=O)C1=CC=C(C=O)C=C1 GOUHYARYYWKXHS-UHFFFAOYSA-N 0.000 description 2
- CPELXLSAUQHCOX-UHFFFAOYSA-N Hydrogen bromide Chemical compound Br CPELXLSAUQHCOX-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- 238000002835 absorbance Methods 0.000 description 2
- 125000000218 acetic acid group Chemical group C(C)(=O)* 0.000 description 2
- BZRRQSJJPUGBAA-UHFFFAOYSA-L cobalt(ii) bromide Chemical compound Br[Co]Br BZRRQSJJPUGBAA-UHFFFAOYSA-L 0.000 description 2
- RJYMRRJVDRJMJW-UHFFFAOYSA-L dibromomanganese Chemical compound Br[Mn]Br RJYMRRJVDRJMJW-UHFFFAOYSA-L 0.000 description 2
- -1 etc. Chemical compound 0.000 description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 2
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229940011182 cobalt acetate Drugs 0.000 description 1
- QAHREYKOYSIQPH-UHFFFAOYSA-L cobalt(II) acetate Chemical compound [Co+2].CC([O-])=O.CC([O-])=O QAHREYKOYSIQPH-UHFFFAOYSA-L 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000007865 diluting Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 229910000042 hydrogen bromide Inorganic materials 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 229940071125 manganese acetate Drugs 0.000 description 1
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical compound [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 description 1
- SGGOJYZMTYGPCH-UHFFFAOYSA-L manganese(2+);naphthalene-2-carboxylate Chemical compound [Mn+2].C1=CC=CC2=CC(C(=O)[O-])=CC=C21.C1=CC=CC2=CC(C(=O)[O-])=CC=C21 SGGOJYZMTYGPCH-UHFFFAOYSA-L 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- GEMHFKXPOCTAIP-UHFFFAOYSA-N n,n-dimethyl-n'-phenylcarbamimidoyl chloride Chemical compound CN(C)C(Cl)=NC1=CC=CC=C1 GEMHFKXPOCTAIP-UHFFFAOYSA-N 0.000 description 1
- 238000003969 polarography Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 239000011541 reaction mixture Substances 0.000 description 1
- 239000012066 reaction slurry Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0053—Details of the reactor
- B01J19/0066—Stirrers
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/16—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation
- C07C51/21—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen
- C07C51/255—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting
- C07C51/265—Preparation of carboxylic acids or their salts, halides or anhydrides by oxidation with molecular oxygen of compounds containing six-membered aromatic rings without ring-splitting having alkyl side chains which are oxidised to carboxyl groups
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/00049—Controlling or regulating processes
- B01J2219/00182—Controlling or regulating processes controlling the level of reactants in the reactor vessel
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
本発明は酢酸溶媒中、コバルト、マンガン、お
よび臭素を含む触媒の存在下、分子状酸素含有ガ
スによりパラキシレンを液相酸化してテレフタル
酸を連続的に製造するに際し、パラキシレンの酸
化に伴つて起こる溶媒酢酸の燃焼損失を減少させ
る方法に関する。
パラキシレンを酢酸溶媒中、コバルト、マンガ
ンおよび臭素を含む触媒の存在下、分子状酸素含
有ガスにより、液相酸化してテレフタル酸を製造
する方法は、SD法として知られ広く工業的に実
施されている。しかしながら、この方法において
はパラキシレンの酸化に伴つて起こる酢酸の酸化
分解による損失を避けることができない。かかる
燃焼による酢酸の損失を低減できれば、テレフタ
ル酸製造の費用軽減が可能となるばかりでなく、
省資源への寄与も計り知れないものがある。
かゝる経済的見地から、溶媒消費低減の工夫
は、例えば触媒成分組成に関しては、特開昭49−
133347、特開昭50−32140、特開昭51−127033、
特開昭51−127034、特開昭51−127035、特開昭52
−77023、特開昭55−51035、添加物として、燐酸
等の強酸を用いる方法に関しては特開昭51−
91221、反応器および反応系の構造に関する方法
としては特公昭54−14098、特開昭54−109939、
更には高温時反応母液を置換する方法として、特
開昭54−90135、反応液スラリー中のテレフタル
酸の濃度に関する方法として、特公昭56−
21014、などが提案されている。又この他にも反
応条件の最適化を指向する触媒濃度および水の濃
度に関する特開昭51−127037、特開昭52−3030、
特開昭52−77022、特開昭53−79836、特開昭54−
52049、特開昭54−70235、特公昭56−21015等が
提示されており、相当の成果を得ていることがう
かがえる。
しかしながら以上のごとく多数の提案において
も溶媒酢酸の燃焼防止効果はまだ十分とは言えな
い。
本発明者は、かゝる実情に鑑み、従来公知の事
例の中で定説となり得ない反応液中の水の効果に
ついて、鋭意研究を行なつた結果、反応液中の水
には、(1)パラキシレンの酸化の過剰反応を緩和さ
せる働き、および(2)溶媒酢酸の酸化分解を抑制
し、燃焼損失を低減する働きがあり、両作用を効
果的に発現させるためには、反応器の適当な場所
に適量の水を供給することが有効であるという知
見を得、この知見を反応器構造に具体化すること
によつて、テレフタル酸の品質を一定に保ちなが
ら、溶媒酢酸の燃焼による損失を低減できること
を見い出し、本発明に到達した。
すなわち、本発明はパラキシレンを酢酸溶媒中
でコバルト、マンガンおよび臭素を含む触媒の存
在下、分子状酸素含有ガスにより、液相酸化して
テレフタル酸を連続的に製造する方法において、
供給パラキシレン100重量部当り２〜50重量部の
水を１以上の撹拌翼を有する反応器の最下部撹拌
翼の上端より上方0.5D（Ｄは反応器内径）より
下であつて、反応器底面より0.03D以上上の位置
に供給し、且つパラキシレン、酢酸および触媒か
らなる原料液、および分子状酸素含有ガスを上記
範囲の位置に供給すると共に、酸化反応液中の水
の濃度を５〜20重量％の範囲に保持し、195〜225
℃の温度においてパラキシレンを連続的に酸化し
テレフタル酸を製造する方法である。
本発明における反応器は、１以上の撹拌翼をも
ち、水供給口、原料液供給口および分子状酸素含
有ガス供給口が、最下部撹拌翼上端より上方
0.5D（Ｄは反応器の内径）より下であつて、反
応器底面より0.03D以上上に位置する構造である
ことが必要であり、更に、反応生成物抜出し口が
最下部撹拌翼上端より上方の液中に存在する構造
であることが好ましい。水供給口については上記
の如く単独に供給口を設けても良いが、分子状酸
素含有ガス供給配管に水配管を接続し、あるいは
反応器の直前で原料供給配管に水配管を接続し供
給口を共用する方法を採用しても良い。
反応器に供給する水としては、水を単独で用い
てもよく、又、反応装置から副生する酢酸その他
微量成分を含有する水、例えば反応器の排ガス凝
縮器からの酢酸及び水からなる凝縮液を使用する
ことも可能であり、経済的に有利である。
水の供給量は、供給パラキシレン100重量部当
り２〜50重量部の範囲が望ましい。前記範囲をこ
えて水の供給量が多くなると、水による反応阻害
の影響が著しくなり、経済的に不利となる。
反応系の水分濃度の調節は反応器の温度制御の
ために設けられる排ガス凝縮器から、主として水
と酢酸からなる凝縮液の一部を抜き出すことによ
り行なわれる、凝縮液の抜出しにより酸化反応液
の水の濃度を５〜20重量％の範囲に保持する。
酸化反応液の水の濃度は５〜20重量％、好まし
くは10〜20重量％の範囲に維持する。水の濃度が
５重量％未満の場合は、酢酸の燃焼割合が増大
し、又、20重量％をこえる場合は酸化反応を阻害
し、得られるテレフタル酸の品質が悪くなる。
触媒としては、コバルト、マンガンおよび臭素
を含む公知の触媒組成物が適用できる。コバルト
成分としては酢酸コバルト、ナフテン酸コバル
ト、臭化コバルト等が、マンガン成分としては酢
酸マンガン、ナフテン酸マンガン、臭化マンガン
等が、臭素成分としては１，１，２，２，テトラ
ブロムエタン、臭化水素、臭化コバルト、臭化マ
ンガン等が利用出来る。触媒濃度は反応液中でそ
れぞれ原子に換算して、Co；50〜1000重量
ppm、Mn；50〜1000重量ppm、Br；400〜2000
重量ppmの範囲で、テレフタル酸の品質に応じ
て適宜選ぶことができる。
反応温度は195〜225℃であり、好ましくは200
〜220℃である。195℃以下では触媒を多量に必要
とし、又、225℃以上では酢酸の酸化分解が減少
せず経済的に不利になる。
反応圧力は前記反応温度において、反応混合物
が実質的に液相で存在する必要があり、これを満
足する程度とする。
反応器に供給される酸素含有ガスとしては、通
常の空気が好適であり、経済的に有利である。あ
るいは純酸素又はこれを不活性ガスと適当な範囲
に希釈したガスも適用できる。
排出ガス中の酸素濃度は反応圧力によつて増減
されるが、通常0.5〜７容量％の範囲であり、テ
レフタル酸の品質に応じて上記範囲より任意に選
ぶことができる。
次に本発明の実施態様の１例を第１図を用いて
説明する。第１図においてそれぞれ、１反応器、
２撹拌機、３原料ガス供給管、４原料液供給管、
５反応生成物抜出し管、６ガス状混合物排出管、
７凝縮器、８受器、９排ガス排出管、１０凝縮液
抜出し管、１１凝縮液還流管、１２最下部撹拌翼
上端位置、１３反応器液面、を示す。
反応方法は、反応器１に所定の触媒および溶媒
を張込み、加圧・加熱した後、撹拌機２により撹
拌しながら原料ガス供給管３から分子状酸素含有
ガスを導入すると共に、原料液供給管４からパラ
キシレン、溶媒および触媒からなる原料液を連続
的に供給して反応を行なわせる。
反応生成物は反応器の液面１３が一定レベルに
保たれるように、反応生成物抜出し管５によつて
取り出される。
水の反応器への供給は水単独の供給口を設ける
ことが好ましいが、設備上はパラキシレン、溶媒
および触媒からなる原料液供給管が反応器に入る
直前に水の供給管を接続し、原料液供給口から行
なわせる方法、あるいは分子状酸素含有ガス供給
管に水の供給管を接続し、これによつて行なわせ
る方法がある。何れの方法によつても水の供給口
は最下部撹拌翼の上端より上方0.5Dより下であ
つて、反応器底面より0.3D以上上の範囲にある
ことが必要である。
主に酸化排ガス、溶媒および水の蒸気からなる
ガス状混合物は、ガス状混合物排出管６から凝縮
器７を通り受器８に入る。受器８では酸化排ガス
と溶媒および水からなる凝縮液に分離される。酸
化排ガスは排ガス排出管９より排出される。凝縮
液は凝縮液抜出し管１０より抜出されると共に、
残部は凝縮液還流管１１を通して反応器へ戻され
る。
凝縮液の抜出し量は、これによる水の抜出し量
によつて反応液中の水の濃度が所定の濃度に保た
れるように調節される。
本発明によれば、テレフタル酸の品質を左右す
る主要因である４−カルボキシベンヅアルデヒド
（以下、4CBAという）含有量およびテレフタル
酸の着色性不純物量を表わすアルカリ溶解液の
340mμでの吸光度（以下、OD340という）がほ
ぼ同等である場合、得られたテレフタル酸に対す
る酢酸の消費率（以下、酢酸燃焼率という）が低
減され、経済的が著しく向上し、工業的に極めて
有用である。
以下の実施例及び比較例において部はいずれも
重量部を示す。
実施例 １
撹拌機、原料ガス供給管、原料液供給管、反応
生成物抜出し管、ガス状混合物排出管、凝縮器、
凝縮液還流管、凝縮液抜出し管および排ガス排出
管を備えた第１図の如き反応器に、１時間当りパ
ラキシレン100部、酢酸（水分10重量％含有）350
部、酢酸コバルト４水塩、0.436部、酢酸マンガ
ン４水塩0.859部、１，１，２，２，テトラブロ
ムエタン、0.454部（即ち、酢酸350部に対し
Co；295ppa、Mn；550ppm、Br；1200pmm）か
らなる原料液に、反応器に入る直前に水12.5部を
連続的に供給し、反応器底部に供給口を有する原
料液供給管から送入し、同じく反応器底部に供給
口を有する原料ガス供給管から空気を導入しなが
ら反応温度210℃、圧力19.5Kg／cm3、平均滞留時
間45分、排ガスの酸素濃度1.5％で反応させた。
凝縮液抜出し管からは主に水と酢酸からなる凝縮
液（水分49.6重量％）を１時間当り92.8部抜出
し、反応液の水の濃度を14重量％に保つた。反応
器における水の生成量40.5部に対し、凝縮液の抜
出しによる水の抜出し量は46.0部であつた。
反応器から取出した反応生成物は結晶槽に導い
て冷却し、次いで固液分離して得た結晶を酢酸で
軽く洗浄した後乾燥し、テレフタル酸の評価試料
とした。
生成したテレフタル酸の収率はパラキシレンに
対して97.3モル％であつた。又、得られたテレフ
タル酸の品質は4CBA含量1480ppm、OD340 1.02
であつた。
こゝで、4CBAはポーラログラフによる分折値
であり、OD340はテレフタル酸２ｇを2N−KOH
水溶液25mlに溶かした溶液の波長340mμにおけ
る吸光度を示している（５cmセル使用）。
酸化排ガス中のCO×（CO2＋CO）生成量を測
定し、酢酸の燃焼率を計算した。この場合の酢酸
燃焼率は6.7％であつた。（生成テレフタル酸重量
に対する酸化分解を受けた酢酸の重量％で示
す）。これらの結果を第１表にまとめる。
実施例 ２
実施例１と同じ反応装置を用い、実施例１の場
合に原料液供給管を経由して供給した水12.5部を
こゝでは原料ガス供給管を利用して空気と共に供
給した。その他の条件は実施例１の場合と全く同
様に実施した。
得られたテレフタル酸の品質は、
4CBA1430ppm、OD34000.97であり、テレフタル
酸の収率97.3モル％、酢酸燃焼率6.6％であつ
た。
実施例２における特徴は、原料ガス供給管に水
を同伴させて供給することにより、反応器内の原
料ガス供給口の閉塞現象が認められなくなり、反
応装置の運転操作が円滑に行なえる利点が生じ
た。これらの結果を第１表に記載する。
比較例 １
実施例１と同じ反応装置において、実施例１で
原料液供給管を経由した水12.5部を、ここでは別
に設けた反応器液面に供給口を有する水の供給管
を通して反応器に供給し、これ以外は実施例１と
全く同様に実施した。
この場合、生成水は１時間当り40.8部に対し、
凝縮液の抜出しによる水の抜出し量は46.3部、反
応液中の水の濃度は14重量％であつた。テレフタ
ル酸の収率は97.2モル％、酢酸燃焼率は7.0重量
％であつた。又、得られたテレフタル酸の品質
は、4CBA1450ppm、OD3401.04であつた。これ
らの結果を第１表に示す。
比較例 ２
実施例１と同じ反応装置において、実施例１で
原料液供給管を経由して供給した水を止め、その
他の条件は実施例１と全く同様に実施した。この
場合、生成水は１時間当り41.2部に対し、凝縮液
抜出し管からは毎時凝縮液を79.9部を抜出すこと
によつて水36.9部を抜出した。
生成したテレフタル酸の収率は97.2モル％、酢
酸燃焼率は7.4重量％であつた。
得られたテレフタル酸の品質は、
4CBA1400ppm、OD340 1.03であつた。これらの
結果を第１表に示す。
実施例 ３
実施例１と同じ反応装置において、実施例１と
同じくパラキシレン100部、酢酸（水分10重量％
含有）350部および触媒（酢酸350部に対して、原
子に換算してそれぞれCo295ppm、Mn550ppm、
およびBr1200ppmを含む）からなる原料混合液
に、反応器に入る直前に水22.5部を連続的に供給
し、原料液供給管から連続的に送入し、温度215
℃、圧力21Kg／cm3Ｇ、排ガスO2濃度２％、平均
滞留時間45分で反応させた。１時間当り凝縮液を
抜出すことにより水57.7部を抜出し、反応液中の
水分を13.8重量％に保つた。この場合の反応によ
る生成水量は１時間当り42.2部であつた。
得られたテレフタル酸の品質および酢酸燃焼率
は第２表に示した。
比較例 ３
実施例３で原料液供給管を経由して供給した水
を止め、その他の条件は実施例３と全く同様に実
施した。
結果は第２表に示した。
実施例 ４
実施例１と全く同様に、パラキシレン、酢酸お
よび触媒からなる原料混合液に、反応器に入る直
前に水12.5部を連続的に供給し、反応器底部に供
給口を有する原料液供給管から送入して、温度
215℃、圧力21Kg／cm3Ｇ、滞留時間45分、排ガス
O2濃度２％で反応させた。
反応生成水量は毎時43.5部であるのに対し、水
の抜出し量を毎時57.5部にして、反応液中の水分
を11.4重量％に保つた。
結果を第２表に示した。
比較例 ４
実施例４で原料液供給管を経由して供給した水
を止め、毎時生成水量が44.0部に対し毎時抜出し
水量を52.0部とすることにより、反応液中の水分
を9.0重量％に保つた。
結果を第２表に示した。
The present invention provides a method for continuously producing terephthalic acid by liquid phase oxidation of paraxylene with molecular oxygen-containing gas in the presence of a catalyst containing cobalt, manganese, and bromine in an acetic acid solvent. The present invention relates to a method for reducing combustion losses of solvent acetic acid. The method of producing terephthalic acid by liquid-phase oxidation of paraxylene in an acetic acid solvent with a molecular oxygen-containing gas in the presence of a catalyst containing cobalt, manganese, and bromine is known as the SD method and is widely practiced industrially. ing. However, in this method, loss due to oxidative decomposition of acetic acid that occurs with the oxidation of paraxylene cannot be avoided. If the loss of acetic acid due to such combustion can be reduced, it will not only be possible to reduce the cost of producing terephthalic acid, but also
The contribution to resource conservation is also immeasurable. From such an economical point of view, methods for reducing solvent consumption, such as the composition of catalyst components, have been proposed in Japanese Patent Application Laid-Open No.
133347, JP-A-50-32140, JP-A-51-127033,
Unexamined Japanese Patent Publication No. 51-127034, Unexamined Publication No. 51-127035, No. 52 Unexamined Publication
-77023, JP-A-51-51035, and JP-A-51-51035 for methods of using strong acids such as phosphoric acid as additives.
91221, methods regarding the structure of reactors and reaction systems are JP-B-14098, JP-A-54-109939,
Furthermore, a method for replacing the reaction mother liquor at high temperatures is disclosed in JP-A-54-90135, and a method for determining the concentration of terephthalic acid in a reaction slurry is disclosed in JP-A-56-1999.
21014, etc. have been proposed. In addition, there are also JP-A No. 51-127037, JP-A No. 52-3030, regarding catalyst concentration and water concentration aimed at optimizing reaction conditions.
JP-A-52-77022, JP-A-53-79836, JP-A-54-
52049, JP-A-54-70235, JP-A-56-21015, etc. have been presented, and it can be seen that considerable results have been obtained. However, even with the numerous proposals mentioned above, the combustion prevention effect of the solvent acetic acid is still not sufficient. In view of the above circumstances, the inventors of the present invention have conducted extensive research on the effect of water in the reaction solution, which cannot be established as an established theory among conventionally known cases, and have found that the effect of water in the reaction solution is (1 (2) suppress the oxidative decomposition of the solvent acetic acid and reduce combustion loss. In order to effectively express both effects, it is necessary to We learned that it is effective to supply the right amount of water to the right place, and by applying this knowledge to the reactor structure, we were able to maintain a constant quality of terephthalic acid while reducing the amount of water produced by the combustion of the solvent acetic acid. We have discovered that loss can be reduced and have arrived at the present invention. That is, the present invention provides a method for continuously producing terephthalic acid by liquid phase oxidation of paraxylene with a molecular oxygen-containing gas in the presence of a catalyst containing cobalt, manganese and bromine in an acetic acid solvent.
2 to 50 parts by weight of water per 100 parts by weight of supplied para-xylene is added to a reactor having one or more stirring blades at a point 0.5D above and below the upper end of the lowest stirring blade (D is the reactor inner diameter). The water concentration in the oxidation reaction solution was increased by 5.0 D, and the raw material liquid consisting of paraxylene, acetic acid, and the catalyst, and the molecular oxygen-containing gas were supplied to the above range. Keep in the range of ~20% by weight, 195-225
This is a method for producing terephthalic acid by continuously oxidizing paraxylene at a temperature of ℃. The reactor in the present invention has one or more stirring blades, and the water supply port, the raw material liquid supply port, and the molecular oxygen-containing gas supply port are located above the upper end of the lowest stirring blade.
The structure must be located below 0.5D (D is the inner diameter of the reactor) and at least 0.03D above the bottom of the reactor, and the reaction product outlet must be located above the top of the lowest stirring blade. Preferably, the structure exists in the upper liquid. Regarding the water supply port, it is possible to provide a separate supply port as described above, but it is also possible to connect the water pipe to the molecular oxygen-containing gas supply pipe, or to connect the water pipe to the raw material supply pipe just before the reactor. You may also adopt a method of sharing. As the water supplied to the reactor, water may be used alone, or water containing acetic acid and other trace components produced by-product from the reactor, such as condensed water consisting of acetic acid and water from the exhaust gas condenser of the reactor. It is also possible to use a liquid, which is economically advantageous. The amount of water supplied is preferably in the range of 2 to 50 parts by weight per 100 parts by weight of paraxylene supplied. If the amount of water supplied exceeds the above range, the influence of reaction inhibition by water becomes significant, which is economically disadvantageous. The water concentration in the reaction system is adjusted by extracting a part of the condensate, which mainly consists of water and acetic acid, from the exhaust gas condenser installed to control the temperature of the reactor. Maintain the water concentration in the range of 5-20% by weight. The concentration of water in the oxidation reaction solution is maintained in the range of 5 to 20% by weight, preferably 10 to 20% by weight. When the concentration of water is less than 5% by weight, the combustion rate of acetic acid increases, and when it exceeds 20% by weight, the oxidation reaction is inhibited and the quality of the obtained terephthalic acid deteriorates. As the catalyst, a known catalyst composition containing cobalt, manganese and bromine can be used. Cobalt components include cobalt acetate, cobalt naphthenate, cobalt bromide, etc. Manganese components include manganese acetate, manganese naphthenate, manganese bromide, etc., and bromine components include 1,1,2,2, tetrabromoethane, Hydrogen bromide, cobalt bromide, manganese bromide, etc. can be used. Catalyst concentration is Co; 50 to 1000 weight in terms of atoms in the reaction solution.
ppm, Mn; 50-1000 ppm by weight, Br; 400-2000
It can be appropriately selected depending on the quality of terephthalic acid within the weight ppm range. The reaction temperature is 195-225℃, preferably 200℃
~220℃. If it is below 195°C, a large amount of catalyst is required, and if it is above 225°C, the oxidative decomposition of acetic acid will not be reduced, which is economically disadvantageous. The reaction pressure is set to a level that satisfies the need for the reaction mixture to exist substantially in a liquid phase at the reaction temperature. As the oxygen-containing gas supplied to the reactor, ordinary air is suitable and economically advantageous. Alternatively, pure oxygen or a gas obtained by diluting it with an inert gas to an appropriate range can also be used. The oxygen concentration in the exhaust gas is increased or decreased depending on the reaction pressure, but is usually in the range of 0.5 to 7% by volume, and can be arbitrarily selected from the above range depending on the quality of the terephthalic acid. Next, one example of an embodiment of the present invention will be explained using FIG. In FIG. 1, one reactor,
2 stirrers, 3 raw material gas supply pipes, 4 raw material liquid supply pipes,
5 reaction product extraction pipe, 6 gaseous mixture discharge pipe,
7 condenser, 8 receiver, 9 exhaust gas discharge pipe, 10 condensate extraction pipe, 11 condensate reflux pipe, 12 lowermost stirring blade upper end position, 13 reactor liquid level. The reaction method is to charge a predetermined catalyst and solvent into a reactor 1, pressurize and heat it, and then introduce a molecular oxygen-containing gas from a raw material gas supply pipe 3 while stirring with a stirrer 2, and supply a raw material liquid. A raw material liquid consisting of paraxylene, a solvent, and a catalyst is continuously supplied from the tube 4 to carry out the reaction. The reaction products are removed by a reaction product withdrawal pipe 5 so that the liquid level 13 of the reactor is maintained at a constant level. For supplying water to the reactor, it is preferable to provide a water-only supply port, but in terms of equipment, the water supply pipe is connected immediately before the raw material liquid supply pipe consisting of paraxylene, solvent, and catalyst enters the reactor. There is a method in which this is carried out from a raw material liquid supply port, or a method in which a water supply pipe is connected to a molecular oxygen-containing gas supply pipe. In either method, the water supply port must be located at least 0.5D below the upper end of the lowest stirring blade and at least 0.3D above the bottom of the reactor. The gaseous mixture consisting mainly of oxidizing exhaust gas, solvent and water vapor enters the receiver 8 from the gaseous mixture discharge pipe 6 through the condenser 7 . In the receiver 8, the oxidized exhaust gas is separated into a condensate consisting of a solvent and water. The oxidizing exhaust gas is discharged from the exhaust gas exhaust pipe 9. The condensate is extracted from the condensate extraction pipe 10, and
The remainder is returned to the reactor through the condensate reflux pipe 11. The amount of condensed liquid withdrawn is adjusted so that the concentration of water in the reaction liquid is maintained at a predetermined concentration by the amount of water withdrawn. According to the present invention, the content of 4-carboxybenzaldehyde (hereinafter referred to as 4CBA), which is the main factor that affects the quality of terephthalic acid, and the amount of coloring impurities of terephthalic acid are determined in the alkaline solution.
When the absorbance at 340 mμ (hereinafter referred to as OD340) is almost the same, the consumption rate of acetic acid to the obtained terephthalic acid (hereinafter referred to as acetic acid combustion rate) is reduced, the economy is significantly improved, and it is extremely effective in industrial terms. Useful. In the following Examples and Comparative Examples, all parts indicate parts by weight. Example 1 Stirrer, raw material gas supply pipe, raw material liquid supply pipe, reaction product extraction pipe, gaseous mixture discharge pipe, condenser,
100 parts of paraxylene and 350 parts of acetic acid (containing 10% water by weight) per hour are placed in a reactor as shown in Figure 1, which is equipped with a condensate reflux pipe, a condensate withdrawal pipe, and an exhaust gas discharge pipe.
parts, cobalt acetate tetrahydrate, 0.436 parts, manganese acetate tetrahydrate, 0.859 parts, 1,1,2,2,tetrabromoethane, 0.454 parts (i.e., per 350 parts of acetic acid)
Immediately before entering the reactor, 12.5 parts of water was continuously supplied to the raw material liquid consisting of Co; 295ppa, Mn: 550ppm, Br; The reaction was carried out at a reaction temperature of 210° C., a pressure of 19.5 Kg/cm 3 , an average residence time of 45 minutes, and an exhaust gas oxygen concentration of 1.5% while introducing air from a raw material gas supply pipe having a supply port at the bottom of the reactor.
From the condensate extraction tube, 92.8 parts of a condensate (water content: 49.6% by weight) consisting mainly of water and acetic acid was extracted per hour to maintain the water concentration of the reaction solution at 14% by weight. While the amount of water produced in the reactor was 40.5 parts, the amount of water removed by drawing out the condensate was 46.0 parts. The reaction product taken out from the reactor was led to a crystallization tank and cooled, and then the crystals obtained by solid-liquid separation were lightly washed with acetic acid and dried, and used as an evaluation sample of terephthalic acid. The yield of terephthalic acid produced was 97.3 mol% based on paraxylene. In addition, the quality of the obtained terephthalic acid is 4CBA content 1480ppm, OD340 1.02
It was hot. Here, 4CBA is a polarographic analysis value, and OD340 is 2g of terephthalic acid with 2N-KOH.
It shows the absorbance at a wavelength of 340 mμ of a solution dissolved in 25 ml of an aqueous solution (using a 5 cm cell). The amount of CO x (CO 2 + CO) produced in the oxidation exhaust gas was measured, and the combustion rate of acetic acid was calculated. The acetic acid combustion rate in this case was 6.7%. (expressed as the weight percent of acetic acid subjected to oxidative decomposition relative to the weight of terephthalic acid produced). These results are summarized in Table 1. Example 2 Using the same reactor as in Example 1, 12.5 parts of water, which was supplied via the raw material liquid supply pipe in Example 1, was supplied together with air using the raw material gas supply pipe. The other conditions were exactly the same as in Example 1. The quality of the obtained terephthalic acid is
4CBA was 1,430 ppm, OD was 34,000.97, the yield of terephthalic acid was 97.3 mol%, and the acetic acid combustion rate was 6.6%. The feature of Example 2 is that by supplying water along with the raw material gas supply pipe, the phenomenon of blockage of the raw material gas supply port in the reactor is not observed, and the operation of the reactor can be performed smoothly. occured. These results are listed in Table 1. Comparative Example 1 In the same reactor as in Example 1, 12.5 parts of the water that had passed through the raw material liquid supply pipe in Example 1 was introduced into the reactor through a separate water supply pipe that had a supply port on the reactor liquid level. The procedure was exactly the same as in Example 1 except for this. In this case, the produced water is 40.8 parts per hour,
The amount of water extracted from the condensate was 46.3 parts, and the concentration of water in the reaction solution was 14% by weight. The yield of terephthalic acid was 97.2 mol%, and the acetic acid combustion rate was 7.0% by weight. Moreover, the quality of the obtained terephthalic acid was 4CBA1450ppm and OD3401.04. These results are shown in Table 1. Comparative Example 2 In the same reaction apparatus as in Example 1, the water supplied via the raw material liquid supply pipe in Example 1 was stopped, and the other conditions were exactly the same as in Example 1. In this case, the produced water was 41.2 parts per hour, and 36.9 parts of water was extracted by withdrawing 79.9 parts of condensate per hour from the condensate extraction pipe. The yield of terephthalic acid produced was 97.2 mol%, and the acetic acid combustion rate was 7.4% by weight. The quality of the obtained terephthalic acid is
4CBA1400ppm, OD340 1.03. These results are shown in Table 1. Example 3 In the same reaction apparatus as in Example 1, 100 parts of paraxylene and acetic acid (moisture 10% by weight)
Contains) 350 parts and catalyst (based on 350 parts of acetic acid, Co295ppm, Mn550ppm, respectively in terms of atoms)
Immediately before entering the reactor, 22.5 parts of water was continuously supplied to the raw material mixture solution consisting of (containing 1200 ppm of Br and
The reaction was carried out at a temperature of .degree. C., a pressure of 21 kg/ cm.sup.3 G, an exhaust gas O.sub.2 concentration of 2%, and an average residence time of 45 minutes. By drawing out the condensate per hour, 57.7 parts of water was drawn out, and the water content in the reaction liquid was maintained at 13.8% by weight. The amount of water produced by the reaction in this case was 42.2 parts per hour. The quality of the obtained terephthalic acid and the acetic acid combustion rate are shown in Table 2. Comparative Example 3 The water supplied via the raw material liquid supply pipe in Example 3 was stopped, and the other conditions were exactly the same as in Example 3. The results are shown in Table 2. Example 4 In exactly the same manner as in Example 1, 12.5 parts of water was continuously supplied to a raw material mixture consisting of paraxylene, acetic acid, and a catalyst immediately before entering the reactor, and a raw material liquid having a supply port at the bottom of the reactor was prepared. Input from the supply pipe and check the temperature
215℃, pressure 21Kg/ cm3G , residence time 45 minutes, exhaust gas
The reaction was carried out at an O 2 concentration of 2%. The amount of water produced by the reaction was 43.5 parts per hour, while the amount of water extracted was 57.5 parts per hour to maintain the water content in the reaction solution at 11.4% by weight. The results are shown in Table 2. Comparative Example 4 In Example 4, the water supplied via the raw material liquid supply pipe was stopped, and the amount of water produced per hour was 44.0 parts, while the amount of water extracted per hour was 52.0 parts, thereby reducing the water content in the reaction liquid to 9.0% by weight. I kept it. The results are shown in Table 2.
【表】【table】
【表】
比較例 ５
実施例１と同じ反応装置において、予め、パラ
キシレン100部、酢酸（水分10重量％含有）350
部、触媒（酢酸コバルト４水塩0.436部、酢酸マ
ンガン４水塩0.859、１，1′2，2′−テトラブロム
エタン0.454部）、及び純水22.5部を予め混合して
調製した原料液を原料液供給管から連続的に送入
し、温度215℃圧力21Kg／cm3Ｇ、排ガスO2濃度２
％、滞留時間45分で反応させた。反応器から凝縮
液を時間当り97.2部（水分59.7％）抜出して、酸
化反応液の水分を13.8重量％に保つた。
テレフタル酸収率は97.4モル％、酢酸燃焼率は
8.9％であつた。又得られたテレフタル酸の品質
は、4CBA970ppm、OD340 1.00であつた。
比較例 ６
実施例１と同じ反応装置において、１時間当た
りパラキシレン100部、含水酢酸（水分13.0重量
％含有）267部および酢酸コバルト四水塩0.436
部、酢酸マンガン四水塩0.859部、１，1′，２，
2′テトラブロムエタン0.454部からなる原料混合
液及び、反応器に入る直前の位置に含水酢酸（水
分13.0重量％含有）96部を原料液供給管から反応
器に連続的に供給し、温度210℃、圧力19.5Kg／
cm2Ｇ、排ガス中のO2濃度２％、平均滞留時間45
分で反応させた。反応中、反応器コンデンサーか
ら凝縮液（酢酸50重量％、水分50重量％）を１時
間当たり92部反応系外に抜き出すことにより、反
応液の水分を14.0％に保持した。
反応器から取り出した反応生成物から実施例１
と同様に処理して得られたテレフタル酸の品質
は、4CBA1800ppm、OD3401.51であり、この場
合のテレフタル酸の収率は97.0モル％、酢酸燃焼
率は7.1％であつた。
比較例 ７
実施例１と同じ反応装置において、１時間当た
りパラキシレン100部、酢酸（水分10重量％含
有）325部および酢酸コバルト四水塩0.436部、酢
酸マンガン四水塩0.859部、１，1′，２，2′テトラ
ブロムエタン0.454部からなる原料混合液及び、
反応器に入る直前の位置に反応器コンデンサーか
ら凝縮液（酢酸50重量％、水分50重量％）25部を
原料供給管を通じ反応器に連続的に供給して比較
例６と同じ温度、圧力条件下で連続的に反応させ
た。反応中、反応器コンデンサーから凝縮液（酢
酸重量50％、水分50重量％）を１時間当たり88部
系外に抜き出して反応液の水分を14.1％に保持す
ると共に、抜き出した凝縮液の一部を上記の如く
利用した。
この場合に得られたテレフタル酸の収率は97.3
モル％、酢酸燃焼率は7.0％であり、テレフタル
酸の品質は4CBA1480ppm、OD340は1.04であつ
た。
比較例６は含水酢酸を、比較例７は反応器コン
デンサーから凝縮液を反応器に入る直前に連続的
に供給した場合であり、実施例１と比較して酢酸
燃焼率が増加し且つテレフタル酸の品質が悪化し
ている。
なお各実施例および各比較例における酢酸燃焼
率とテレフタル酸の品質（4CBA含量）の関係を
第２図に示した。第２図より、水を単独に反応器
の特定位置に供給した本発明での各実施例におい
て、水の供給方法を変えた各比較例と比べて酢酸
燃焼率が低下していることが分かる。[Table] Comparative Example 5 In the same reaction apparatus as in Example 1, 100 parts of paraxylene and 350 parts of acetic acid (containing 10% water by weight) were prepared in advance.
A raw material solution prepared by pre-mixing 1 part, catalyst (0.436 parts of cobalt acetate tetrahydrate, 0.859 parts of manganese acetate tetrahydrate, 0.454 parts of 1,1'2,2'-tetrabromoethane), and 22.5 parts of pure water. The raw material liquid is continuously fed from the supply pipe, the temperature is 215℃, the pressure is 21Kg/ cm3G , and the exhaust gas O2 concentration is 2.
%, the reaction was carried out with a residence time of 45 minutes. 97.2 parts (water content: 59.7%) of the condensate was withdrawn from the reactor per hour to maintain the water content of the oxidation reaction liquid at 13.8% by weight. Terephthalic acid yield is 97.4 mol%, acetic acid combustion rate is
It was 8.9%. The quality of the obtained terephthalic acid was 4CBA970ppm and OD340 1.00. Comparative Example 6 In the same reactor as Example 1, 100 parts of paraxylene, 267 parts of hydrated acetic acid (containing 13.0% water by weight) and 0.436 parts of cobalt acetate tetrahydrate per hour.
parts, manganese acetate tetrahydrate 0.859 parts, 1,1′,2,
A raw material mixture consisting of 0.454 parts of 2'tetrabromoethane and 96 parts of hydrated acetic acid (containing 13.0% water by weight) were continuously supplied from the raw material liquid supply pipe to the reactor immediately before entering the reactor, and the temperature was 210. °C, pressure 19.5Kg/
cm 2 G, O 2 concentration in exhaust gas 2%, average residence time 45
It reacted in minutes. During the reaction, 92 parts of a condensate (50% by weight of acetic acid, 50% by weight of water) per hour was drawn out of the reaction system from the reactor condenser to maintain the water content of the reaction liquid at 14.0%. Example 1 from the reaction product taken out from the reactor
The quality of terephthalic acid obtained by treatment in the same manner as above was 4CBA 1800 ppm and OD 340 1.51, the yield of terephthalic acid in this case was 97.0 mol%, and the acetic acid combustion rate was 7.1%. Comparative Example 7 In the same reaction apparatus as in Example 1, 100 parts of paraxylene, 325 parts of acetic acid (containing 10% water by weight), 0.436 parts of cobalt acetate tetrahydrate, 0.859 parts of manganese acetate tetrahydrate, 1,1 A raw material mixture consisting of 0.454 parts of ',2,2'tetrabromoethane;
25 parts of condensate (50% by weight acetic acid, 50% by weight water) was continuously supplied to the reactor from the reactor condenser immediately before entering the reactor through the raw material supply pipe, and the same temperature and pressure conditions as in Comparative Example 6 were maintained. The reaction was carried out continuously below. During the reaction, 88 parts of condensate (50% by weight of acetic acid, 50% by weight of water) is extracted from the reactor condenser per hour to maintain the moisture content of the reaction liquid at 14.1%, and a portion of the condensate is extracted from the reactor condenser. was used as described above. The yield of terephthalic acid obtained in this case is 97.3
The mol% and acetic acid combustion rate were 7.0%, the quality of terephthalic acid was 4CBA1480ppm, and the OD 340 was 1.04. Comparative Example 6 is a case in which hydrous acetic acid is continuously supplied, and Comparative Example 7 is a case in which condensate from a reactor condenser is continuously supplied immediately before entering the reactor. quality is deteriorating. Incidentally, the relationship between the acetic acid combustion rate and the quality of terephthalic acid (4CBA content) in each Example and each Comparative Example is shown in FIG. From Figure 2, it can be seen that in each of the examples of the present invention in which water was supplied alone to a specific position of the reactor, the acetic acid combustion rate was lower than in each comparative example in which the water supply method was changed. .
第１図は本発明に使用する反応器である。
第２図は各実施例および各比較例における酢酸
燃焼率とテレフタル酸の品質（4CBA含量）の関
係を示す図面である。
FIG. 1 shows a reactor used in the present invention. FIG. 2 is a drawing showing the relationship between the acetic acid combustion rate and the quality of terephthalic acid (4CBA content) in each Example and each Comparative Example.
Claims (1)
ンガンおよび臭素を含む触媒の存在下、分子状酸
素含有ガスにより液相酸化してテレフタル酸を連
続的に製造する方法において、供給パラキシレン
100重量部当り２〜50重量部の水を、１以上の撹
拌翼を有する反応器の最下部撹拌翼の上端より、
上方0.5D（Ｄは反応器内径）より下であつて、
反応器底面より0.03D以上上の位置に供給し、且
つパラキシレン、酢酸および触媒からなる原料
液、および分子状酸素含有ガスを上記範囲の位置
に供給すると共に、酸化反応液中の水の濃度を５
〜20重量％の範囲に維持し、195〜225℃の温度に
おいてパラキシレンを連続的に酸化することを特
徴とするテレフタル酸の製造法。1 In a method for continuously producing terephthalic acid by liquid-phase oxidation of para-xylene with a molecular oxygen-containing gas in the presence of a catalyst containing cobalt, manganese and bromine in an acetic acid solvent, the supplied para-xylene is
2 to 50 parts by weight of water per 100 parts by weight is added from the upper end of the lowest stirring blade of a reactor having one or more stirring blades.
Below the upper 0.5D (D is the inner diameter of the reactor),
It is supplied to a position 0.03D or more above the bottom of the reactor, and the raw material liquid consisting of paraxylene, acetic acid and catalyst, and molecular oxygen-containing gas are supplied to the position within the above range, and the concentration of water in the oxidation reaction liquid is 5
A process for producing terephthalic acid, characterized in that paraxylene is continuously oxidized at a temperature of 195-225°C, maintaining the content in the range of ~20% by weight.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56151149A JPS5852243A (en) | 1981-09-24 | 1981-09-24 | Preparation of terephthalic acid |
| GB08226863A GB2106797B (en) | 1981-09-24 | 1982-09-21 | Process and apparatus for producing terephthalic acid by liquid phase oxidation of paraxylene |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56151149A JPS5852243A (en) | 1981-09-24 | 1981-09-24 | Preparation of terephthalic acid |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5852243A JPS5852243A (en) | 1983-03-28 |
| JPS6246533B2 true JPS6246533B2 (en) | 1987-10-02 |
Family
ID=15512431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56151149A Granted JPS5852243A (en) | 1981-09-24 | 1981-09-24 | Preparation of terephthalic acid |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5852243A (en) |
| GB (1) | GB2106797B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02269535A (en) * | 1989-04-11 | 1990-11-02 | Fsk Corp | Working method for work |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH078821B2 (en) * | 1986-09-26 | 1995-02-01 | 三井石油化学工業株式会社 | Method for producing aromatic carboxylic acid |
| US5371283A (en) * | 1993-12-22 | 1994-12-06 | Praxair Technology, Inc. | Terephthalic acid production |
| KR100988684B1 (en) * | 2008-04-16 | 2010-10-18 | 삼남석유화학 주식회사 | Oxidation reactor for manufacturing of crude terephtalic acid |
| WO2020102639A1 (en) * | 2018-11-16 | 2020-05-22 | Bp Corporation North America Inc. | Process for manufacturing aromatic carboxylic acids |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5032140A (en) * | 1973-07-28 | 1975-03-28 | ||
| JPS5365841A (en) * | 1976-11-26 | 1978-06-12 | Asahi Chem Ind Co Ltd | Preparation of terephthalic acid |
| JPS5384933A (en) * | 1976-12-30 | 1978-07-26 | Mitsubishi Chem Ind Ltd | Preparation of terephthalic acid |
| JPS53100339A (en) * | 1977-02-14 | 1978-09-01 | Sanwa Seiki Mfg Co Ltd | Shearing type shaft coupling |
| JPS5452049A (en) * | 1977-09-30 | 1979-04-24 | Toray Ind Inc | Preparation of high quality terephthalic acid |
-
1981
- 1981-09-24 JP JP56151149A patent/JPS5852243A/en active Granted
-
1982
- 1982-09-21 GB GB08226863A patent/GB2106797B/en not_active Expired
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5032140A (en) * | 1973-07-28 | 1975-03-28 | ||
| JPS5365841A (en) * | 1976-11-26 | 1978-06-12 | Asahi Chem Ind Co Ltd | Preparation of terephthalic acid |
| JPS5384933A (en) * | 1976-12-30 | 1978-07-26 | Mitsubishi Chem Ind Ltd | Preparation of terephthalic acid |
| JPS53100339A (en) * | 1977-02-14 | 1978-09-01 | Sanwa Seiki Mfg Co Ltd | Shearing type shaft coupling |
| JPS5452049A (en) * | 1977-09-30 | 1979-04-24 | Toray Ind Inc | Preparation of high quality terephthalic acid |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02269535A (en) * | 1989-04-11 | 1990-11-02 | Fsk Corp | Working method for work |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2106797A (en) | 1983-04-20 |
| GB2106797B (en) | 1985-08-21 |
| JPS5852243A (en) | 1983-03-28 |
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