Upload
dodieu
View
214
Download
0
Embed Size (px)
Citation preview
FORMAT OF MASS BALANCE
Product : Di-ethyl Phthalate (DEP) Kg Per Batch : 5000
Stage: 1 Reaction & Distillation Batches Per Month: 25
Name of The Raw Material
Input qty. in kg / Batch
Recycle qty. in kg / Batch
Liquid Effluent in kg / batch
Solid Waste in kg / batch
Emissions in kg / batch
Output in kg / batch
PATHALIC
ANHYDRIDE 3500 - - - - -
ETHYL ALCOHOL
2600 - - - -
CATALYST 150 300 - - - -
CRUDE
D E P
150
Total 6250 300 150 - - 5800
Stage: 2 Neutralisation, Washing & Drying.
Name of The Raw Material
Input qty. in kg / Batch
Recycle qty. in kg / Batch
Liquid Effluent in kg / batch
Solid Waste in kg / batch
Emissions in kg / batch
Output in kg / batch
CRUDE D E P 5800 - - - -
WASH WATER 1500 - - - -
CAUSTIC SODA 120 - - - -
Total 7420 2420 - - 5000
Note: 1 Disposal method for liquid effluent and solid hazardous waste, Details of scrubbers installed for controlling process emissions.
�
�
�
�
�
�
Product : FORMALDEHYDE (37%) Kg Per Day : 10,000
Stage: 1 Per Month : 300 Tonnes
Name of The Raw Material
Input qty. in kg / Batch
Recycle qty. in kg / Batch
Liquid Effluent in kg / batch
Solid Waste in kg / batch
Emissions in kg / Day
Output in kg / Day
Methyl Alcohol
(Methanol) 5000 - - -
DM Water 3500 - - -
AIR (N2 & O2) 15000 - - - N2 + O2
13300
FORMALDEHYDE (Product) 10000
Note: 1 Disposal method for liquid effluent and solid hazardous waste, Details of scrubbers installed for controlling process emissions.
No Liquid Effluent.
�
�
�
�
�
�
�
�
���������
!" !"#$%&'($#$)&)#"'* +(,'
Diethyl Phthalate (DEP) is a colourless oily liquid with a slight isomatic odour. It is
commonly used in the production of plastic to give flexibility to the production. It is also
used in insecticides, mosquito repellents and cosmetics such as hair sprays, nail polish.
It is also used in detergents, after shave lotions and skin care preparations. Used also
extensively by Agabathis manufacturing industries.
(See next chapter)
���������
MANUFACTURING PROCESS
Two main raw materials used are:
i) Phthalic Anhydride
ii) Industrial Ethyl Alcohol
Required quantity Ethyl Alcohol - slightly excess - is charged to the Reaction kettle from
overhead feed tank. Measured quantity of Phthalic Anhydride and Catalyst –
concentrated sulphuric acid or Para Toluene sulphuric acid PTSA - are then added
under constant stirring. Reactants are then heated to desired temperature by steam.
During reaction water is produced which has to be removed continuously to facilitate
completion of reaction. Water vapour along with ethyl alcohol vapour are condensed
and the condensate is fed to a Distillation Column to separate the Ethyl Alcohol and
water. From the top of the Distillation Column Ethyl Alcohol Vapours are taken to a
Condenser, condensed and partly returned to the column as reflux and rest cooled and
taken to Receiver, from where it is taken back to the Reaction Kettle. Water is removed
from the bottom of the Column.
When the reaction is complete, as judged from the Acid value of the production,
unreacted Alcohol is removed by distillation and recycled in the next batch.
Contents of the Reaction Kettle is then neutralised using caustic soda or sodium
carbonate, washed with water. Washing to be thorough. After settling, wash water is
drained off. Contents of the Reaction Vessel - Crude DEP - is then heated under
vacuum to remove traces of water. Stripping steam is sometimes admitted to the
Reaction Vessel to remove any adour. Contents are then cooled using cooling water in
the limpet coil and collected in the receiver for packing.
At times, DEP may have to be treated with activated carbon for removal of any colour.
After this it is filtered and taken for storage.
����� � � �
#!" MANUFACTURING PROCESS
$%&'()*+,-*+
Raw materials used in this process for the production of Formaldehyde are Methanol
(Methyl Alcohol – CH3OH) and DM water. Formaldehyde is produced by Catalytic
Vapour Phase dehydrogenation of Methanol and the hydrogen librated reacts with
Oxygen to form water. Main reactions are as follows :
CH3OH HCHO + H2
H2 + (O) H2O
Dehydrogenation reaction is endothermic and the second reaction is exothermic, net
result being liberation of heat. This heat is used for generating steam required for the
process. Another reaction which might take place in a smaller scale
HCHO CO + H2
CO + (O) CO2
Methanol from Storage Tank is pumped to the Overhead Feed Tank . DM water from
the DM Water Tank is taken to the Overhead DM water Feed Tank . Methanol and DM
water from the respective Overhead Feed Tank is taken to the Mixer in correct
proportion from where it is pumped to the Vapouriser . Vapouriser is maintained at a
specific temperature and air is purged through it by Air Blower . Air carries the
Methanol-water vapour out of the Vaporisor.
./.
���� � � �
: II - 2 :
The Methanol-water vapours mixed with air is super heated in a Superheated before
entering the Reactor . Catalyst (Silver granules) is kept in the top portion of Reactor.
The Methanol-water-air mixture passes through the bed of catalyst, when the
conversion of Methanol to formaldehyde takes place and also side reactions which
produce C02, CO and water. The catalyst bed is maintained at a temperature of around
600�C by controlling process parameters. The gases leaving the catalyst bed-
formaldehyde, C02, CO, water vapour, unreacted Methanol, O2 and Nitrogen - at a
temperature of around 600�C are cooled in an inbuilt shell and Tube Heat Exchanger,
by water. Here gases are cooled to around 150�C and steam is produced. The steam
produced is separated in Steam Separator and used in the process.
The gases leaving the Heat Exchanger are further cooled in Shell & Tube Coolers ) to
around 65-70�C before admitting to Absorber, where they are scrubbed with dilute
formaldehyde solution. 37% formaldehyde solution is drawn out from the bottom of
Absorber and sent to Receivers. Heat of solution produced in the Absorber is removed
by cooling the circulating solution in Cooler . Finally the gas is scrubbed with pure DM
water in the Circulation Tower and the tail gases are exhausted to atmosphere.
Table No.1 Details of Water Consumption
Note: # - Fresh water, * - ETP treated water,
�
Table No.2 Details of Effluent Generation
�
Sr. No. Description Water Consumption (M3/Day)
1. Domestic #2 2. Industrial a. Processing #5
b. Washing #1 d. Cooling 40 (#33+*7) e. Boiler Feed #5 f. D.M. Plant water for backwash #1 Industrial Total 52 (#45+*7)
3. Other (Gardening) *2 • Grand Total 56 (#47+*9)
Sr. No.
Description Effluent Generation (M3/Day)
1. Domestic 1.5 2. Industrial a. Processing 3
b. Washing 0.8 d. Cooling Tower blowdown 4
e. Boiler blowdown 0.5 f. D.M. Plant back wash 0.9
Industrial Total 9.2