Document rxwL54mdrkZm2OdneY2E0Mzwv

px H o S f MONSANTO INCUS'! RIAL CHEMICALS COMPANY Sauget, lili noi s May 8 , 1379 Messrs : D. B. Edwards - G.O. D. P. Roman G.O. J. A. Hi nkebe in *- G.O. J. N. Siegel - G.O. F. B. Matthews W. L. Smul 1 D. C. Armstrong D. J. Metherd U. L. Sul 1ivan P. T. Ki rk Process Holders W.G.K. Standard Documents Vital Records - G.O. ^-Technical Information Center (2) ^ fi\C- t -*j U * J'Ci!:l!_ ~r f|,("W/'V .-`''-f. .* op3;. TEHTATIVE AMENDMENT "E" TITLE Tentative Amendment ME" to the Standard Manufacturing Process Description for Parach1oropheno1 and Orthochlorophenol, dated February, 197** Dept. 237. OBJECTIVE To ninimize formation of dioxins by deleting the neutralization of crude monoch1orophenol with 50% caustic. PRESENT PRACTICE Dept. 237 currently produces refined chiorophenols in a batchwise operation. Virgin and recycled phenol are chlorinated to a specific gravity of 1.212 to 1.215 to produce crude monochlorophenol. The crude chlorinated mass is then aerated for four hours to reduce dissolved HC1 from 2000-3000 ppm to about kO ppm. The material is then neutralized with approximately 5 gallons of 50% caustic for an 8CC0 gallon still charge. A still charge contains six chlorinator batches. Once the still is charged, the material is heated and vacuum is applied. Water is first removed from the batch. Forward flow is diverted to the Wet Fractions Storage Tank until the water content is less than 0.25%. The reflux ratio is then varied to separate the various chiorophenol isomers. Residue is removed from the still once every 10-- 15 batches. CIJO 001! Tentative Amendment "EM Parochlorcpnencl & 0 rthoch1orophcnol, Dept. 237 Page 2 5/8/79 W.G.K. SUGGESTED CHANGE Neutra1ization of crude monochlorophenol with caustic will be eliminated. Since most of the water content of crude monochlorophenol previously originated from the caustic neutralization step, no wet fractions cut will be made. The dry fractions cut will be sampled for water and if the con centration is more than 0 .2-"!;, the fractions will be transferred to the Wet Fractions Storage Tank. Due to increased levels of HC1 in the crude monochlorophenol, it is impor tant to eliminate water from the system. The most important source of moisture after elimination of caustic is the still pot washout. The normal procedure of charging the still with 2000 gallon's of water will continue to be followed. However, after each washout, the still will be charged with dry fractions and dried in the normal manner. Wet fractions from this source will be accumulated and eventually redried. JUSTIFICATION Deletion of the caustic neutralization step is expected to reduce or elimin ate dioxins and make a more environmentally acceptable product. Thi s process change is also expected to reduce batch cycle tires due to elimination of the wet fractions cut. Residue formation and waste disposal costs will also be reduced. DISCUSSION Elimination of the caustic neutralization step will expose the column, still pot, and condensers to increased levels of HC1. In order to quantify the risk of corrosion, test coupons were placed in the system to determine corrosion rates before and after caustic elimination. The data obtained from these tests will be examined and action taken if necessary. Other steps will be taken to minimize HC1 and water content In crude mono chlorophenol. Aeraticn.time wi 11 be monitored to insure that the full four hour period is used. In addition, phenol shipments will be sampled routinely for water and rejected if water content Is greater than 0 .07-i- Additional data concerning this process change is provided in TSD Progress Report 91370:^507, Nos. 1 and 2, `'Eliminate Neutralization of Crude Chlorophenols," dated 10/27/75 and 11/19/75, by G. E. Hertz (F. J. Helmer). YIELDS A yield improvement is expected as a result of reduced residue and fractions generation- This improvement will be quantified after demonstration of the process change. Tentative Amendment "E" Pa radi 1orophenol O r t h o c h 1orophcnol Page 3 5/8/79 W.G.K. SAFETY No additional safety precautions will be taken as a result of this process change. QUALITY Samples taken before the process amendment indicated that snail amounts of chlorinated dibenzodioxins were formed as a result of the neutralization step. Elimination of this step is expected to reduce dioxin concentrations to lower levels. Results of analyses will be studied to determine if addi tional process modifications are necessary. EXTENT OF DEMONSTRATION Starl-up and finalization of operating procedures and conditions will requi two months. If difficulties arise, due to increased corrosion or product quality, this period may be extended. CRITERIA FOR ACCEPTANCE 1. No unexpected safety problems of unacceptable nature develop. 2. Formation of dioxins is reduced to an acceptable level. < 3. Ho corrosion problems of an unacceptable nature develop. Prepared 5y: E. A. (Fy sms Tenu a live Amendment n E" Pa rachloroph^no S Or choch 1orophenol Page h 5/3/79 W . G.K. APPROVED SY: H VI j^ (.r**^O- -y G .L., Process /^.chnoiocy (?/ r.J/y Date APPROVED BY: Producton Supervi sor > /9/7- Date -- /?.7//.;/ y / / < // ////'/.A-*':/ 'f' -l1 \^ r/T>/ /^" ' ! -,. r-'i?A //<;;^Vv " y0 )?gn.j^K&U Business Gro>.y Date U M t A A s l $ M r9,/7 i.'Mgr. , Product rA,cce(ptJaa 1ity Date i) PROCESS TECHNOLOGY SAFETY REVIEW COMMITTEE :[\/l /!c<a- a r.r^ / _.A-M ' p . births Dat (, If<s! 'i-* ' pate 6/:'<*h i Date Operating Superintencent i7 ^ 7 V W c i U U Gen . Mf g . Superi n tendent 'A 7 Date 'S - 2 Z Q <\ Date / (. / / . / </tj/7`/ iSD P rocess Gp. Supe rintancent Da te . * .//n, / i/JJ/9*} TSD General Suoerintencent Date _____________ ______*/ < f 3 ? / ? /7 G. L . f4` P 1an t/^/rpees*: Res e a ren ' Da Ve -y N>. .? % /V) V.*" r.f r f '?fi v,/;-~v*y-3________ 'LL2Lu LorsL.. P r e v e n t io n Sp a cY al i s t Date Manuracturing Manager t/-'* Date srcs