Document zQm3wGpz5ZZLBoxY57aNan22g
July 22, 1991
DOW CHEMICAL U.S.A.
LOUISIANA APPLIED SCIENCE AND TECHNOLOGY LABORATORIES P. O. BOX 400
PLAQUEMINE. LA. 70765.0400 504.3S9.8000
Chris Messelt - 6601 Steve Smith - 6601 Rene Tassin - 6601 Emmett Brown - 2511
OXYCHLORINATION OF ETHYLENE LOWER OXYGEN FLAMMABILITY LIMIT The purpose of this work was to determine the LOFL (lower oxygen flaminability limit) for reactors R-201 and R-202 at the Vinyl II Plant based on current operating parameters and to determine the change in LOFL assuming that a 2500 lb/hr POLY C ethylene vent stream is utilized as a source of feed to R-202.
BACKGROUND
Four (4) empirical models have been proposed in the Dow literature to generate LOFL values for the oxychlorination of ethylene process (1J:
(1) LOFL(X) = (2) LOFL(X) =
(3) LOFL(Z) =
(4) LOFL(X) =
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REDACTED
CONFIDENTIAL
[1] "Mathematical Analysis of Previously Published Ethylene Oxychlori nation Flammability Studies", CK 88-41, Pamela Berg, 20-0CT-88.
Dov Confidential
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Equation 2 is referred to as the "Hill Equation" and is used in all of Dow's oxychlorination of ethylene processes. Equation 2 assumes that both CO and HCL do not effect the LOFL.
Equation 3 is a modified version of equation 2; the modification being _ that the data used in the development of equation 2 was transformed to . separate the ethylene component into two parts: that which is coming into the reactor as recycle and that which is direct ethylene feed. Using SA'S and outside literature sources, the author showed that both CO and HCL effect the lower oxygen flammable limit.
Equation 4 is referred to as the "Midland Equation" and was generated to account for non-turbulent flow conditions.
RESULTS
Given below is a listing of data ranges used in the development of the different LOFL equations. Also included are key operating parameters... .. for R-201 and R-202 taken on the morning of July 10, 1991 at the Vinyl II Plant. The LOFL values have been calculated for both trains and for R-202 with the addition of the Poly C ethylene vent stream:
Component
Hill Eq's
Ethylene Methane Ethane Carbon monoxide Carbon dioxide HCL Nitrogen
Midland Eq. R-201 R-202 R-202 (Poly C) ______ _____ _____ ___________ -
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Percent Oxygen in feed to reactor
LOFL (1) ........... Heat Capacity Correlation LOFL (2) ........... Hill Equation LOFL (3) ........... Modified Hill Equation LOFL (4) ........... Midland Equation
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Dow Confidential (2)
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The LOFL values calculated using equations 1, 2 and 3 show all three operating scenarios to be below the lover oxygen flammable limit. The Midland equation suggests that our current operation is in the flammable region. Past operating experience tells us that this is not the case.
The addition of the 2500 lb/hr Poly C ethylene vent stream to train R-202 will not adversely effect the lover oxygen flammability limit. Therefore, we will proceed with our research goals of determining the effects of this stream on ethylene dichloride cracking pattern (La.) and on oxychlorination catalyst activity (Texas, R&D).
Please contact me with any comments or concerns you may have.
Sincerely,
Bryan Adams C&PP Research
Attachments
Dow Confidential (3)
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Lower Oxygen Flammable Limit (LOFL) Oxychlorination of Ethylene
Reactor Inlet Oxygen (mol %)
Dow Confidential 19-JUL-91
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CONFIDENTIAL
REDACTED
R&S149849
OXYCHLORINATION RECYCLE GAS ANALYSIS
TRAIN = R--201 DATE = 10-JUL-91 TIME = 08:00
-
Elution Compound Mole Wt. MOL RRF AREA CNT MOL FRAC WT FRAC (min)
TCD ANALYSIS
FID ANALYSIS
CONFIDENTIAL
in r . A
AVERAGE MOLECULAR WEIGHT = DOW CONFIDENTIAL
R&S149850
OXYCHLORINATION RECYCLE GAS ANALYSIS TRAIN = R-202 DATE = 10-JUL-91 TIME = 08:05
Elution Compound Mole Wt. MOL RRF AREA CNT MOL FRAC WT FRAC (min) TCD ANALYSIS
FID ANALYSIS
CONFIDENTIAL
REDACTED
DOW CONFIDENTIAL
n
C/3
C0cDn0
GC FID/TCD Analysis of the Poly C Recycle Ethylene Stream at LHC 3
INERTS ANALYSIS
GC ANALYSIS
Wt. % corrected analysis
GC analysis
REDACTED
CONFIDENTIAL
R&s149352
R-201 SYSTEM (10-JUL-91)
OBS DATE
1 10-JUL-1991 06:00 2 10-JUL-1991 06:30 3 10-JUL-1991 07:00 4 10-JUL-1991 07:30 5 10-JUL-1991 08:00 6 10-JUL-1991 08:30
OBS TAG 4 TAG 5
TAG_1
TAG 2
TAG 6
TAG 7
TAG 3 TAG 8
Variable Label
TAG_1 TAG2 TAG_3 TAG_4 TAGS TAG_6 TAG_7 TAG 8
N
Variable Label
Mean
Std Dev
Minimum
Maximum
R-202 SYSTEM (10-JUL-91)
OBS DATE
1 10-JUL-1991 06:00 2 10-JUL-1991 06:30 3 10-JUL-1991 07:00 4 10-JUL-1991 07:30 5 10-JUL-1991 08:00 6 10-JUL-1991 08:30
OBS TAG_4
TAG_5
1 2 3 4 5 6
Variable Label
N
TAG_1 TAG_2 TAG_3 TAG_4 TAG_5 TAG_6 TAG_7 TAG 8
TAG 1 TAG 6 Mean
TAG 2
TAG 3
TAG 7
TAG 8
Std Dev
Minimum
: CONFIDENTIAL
Variable Label
TAG_1 TAG_2 TAG_3 TAG_4 TAG5 TAG6 TAG_7 TAG 8
Maximum
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R&S149854
OXY-EDC Area Concerns
Concern: Oxygen system contamination Improvements:
Emphasis on field tag identification of 02 service equipment
. Measures in place: Handling and identification procedures for 02 service Use of graphite free gaskets and Flurolube lubricant Cleaning procedures, bagging and labeling for 02 service Ultraviolet light inspection- prior to installing item in 02 service
Opportunities: Update procedure for handling and identification of 02 service equipment
src:8/91
OXY-EDC Area Concerns
Concerns: Packing Deterioration- Organics and Temperature
Improvements: Approximately 800 ft3 kynar packing in C-211 EDC condensing column bottom replacing polypropylene
Opportunities: Inspect/repack C-212 in 9/91
src:8/91
OXY-EDC Area Concerns
Concern: VCM in acid to OXY Measures in Place:
Analysis of C-120 overhead for VCM with alarming
Operating discipline on C-120 Monitor & alarm C-120 tray temps Opportunities: Mod5 control
src:8/91
CONFIDENTIAL
R&S149857
OXY-EDC Area Concerns
Concern: Ethylene entering 02 header Improvements: None since last review Measures in Place:
02 header maintained 5 PSI above ethylene pressure
Low flow trips on all reactor feeds Opportunities:
Mod5 control
srC:8/91
Ecology Area
Concern: Polymerized chloroprene, moisture &/or iron in T-420 vent KO drum
Improvements: 02 analyzer on C270
Measures in Place: Sampling and analysis procedures
Opportunities:
src:8/91
CONFIDENTIAL
R&S 149859
Ecology Area
Concern: Mixing Propylene with process in T-410
Improvements: Measures in Place:
T-410 is emptied and steamed out prior and after burning oil from K-320 C3H6 system
Oil drummed to allow C3H6 to vent prior to putting in T-410
Opportunities:
src:8/91
BIF WASTE CHARACTERIZATION
WASTE STREAM NUMBER WASTE NAME PLANT NAME
PHYSICAL PROPERTIES
HEAT OF COMBUSTION VISCOSITY
FLASH POINT HALOGENS SPECIFIC GRAVITY
ASH
T-410 WASTE OILS
vinyl n
2000-7000 BTU/LB 1.1-1.6 CENTISTOKES
ND 25-65 WT.%
1.1-1.35 0.05-.15 %
COMPONENT
METALS
ARSENIC BARIUM CADMIUM CHROMIUM
LEAD MERCURY
SILVER ANTIMONY BERYLLIUM THALLIUM
ORGANIC ANALYTES
BENZENE CARBON TETRACHLORIDE ' CHLOROBENZENE 2-CHLOROETHYLVINYL ETHER
CHLOROFORM 1.1-DICHLOROETHANE 1,2-DICHLOROEIHANE TRANS 1,2-DICHLOROETHANE TETRACHLOROETHANE 1.1,2-TRICHLOROETHANE TRICHLOROETHANE
VINYL CHLORIDE 2-CHLORONAPHTHALENE
1,2-DICHLOROBENZENE 1,3-DICHLOROBENZENE 1,4-DICHLOROBENZENE
FLUORENE HEXACHLOROETHANE
NAPHTHALENE CHLORONATED PROPENES CHLORONATED BUTENES
NVM & UNKNOWNS PYRIDENE
WASTE OILS
CONCENTRATION RANGE
PPM
BDL 0.001-0.15 0.001-0.2 0.01-10.0 0.00-0.5 0.001-0.8 0.001-20.0 0.001-0.4
BDL BDL
WT. %
0.2-1.0 2.0-10.0 0.0-0.5 0.0-0.5 2.0-10.0 0.5-2.0 1.0-30.0 0.1-1.0 0.0-1.0 1.0-5.0 0.1-1.0 0.0-1.0 0.0-1.0 0.0-1.0 0.0-1.0 0.0-1.0 0.0-1.0 0.0-1.0 0.0-1.0 0.0-15.0 0.0-15.0 1.0-25.0 0.0-10.0 0.0-100.0
ANALYSIS
PROCESS KNOWLEDGE
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