Specifications

Feed

1. Benzene- with 0.2% non-nitratable inerts Assumption:99.8%?2. Nitric Acid- 68% w/w3. Sulfuric acid- 20% w/w oleum4. Sodium Hydroxide- 47% w/w

By products

1. Dintrobenzene 2. Nitrophenol – 0.35% yield,

a. Dinitrophenolb. Trinitrophenol

3. Oxalic acid4. NOx

Reactor

1. Temperature in the reactor should not be greater than 140oC in the reactor or sulfornication occurs

2. Concentration of the sulphuric acid must not be >70% w/w3. 100% conversion of HNO34. Reactions occurring

a. Main<150ppmi. C6H6+HNO3------> C6H5NO2+H2O

b. Side <2000ppm eachi. C6H5NO2+HNO3 ------> C6H4(NO2)2+H2O (forms when NB

produced reaches 150ppm)ii. C6H6+3HNO3------> C6H4(NO2)2OH+2H2O+HNO2iii. C6H6+4HNO3------> C6H4(NO2)3OH+3H2O+HNO2iv. 2HNO2------>H2O+NO+NO2v. 3NO2+H2O------>HNO3+NO

c.

Separator

1. High temperature2. 10 mins residence time3. Separator- Nitrobenzene water separator

a. NB Superficial velocity < 0.0001m/s b. Water phase <0.004m/s

Re-concentrator

1. Heat from reaction is used to re-concentrate the H2SO4 should make up 80% of the total heat load

Washer

1. Removes oxidised impurities from benzene, nitrophenol and oxalic acid. (All impurities removed at this stage).

2. NaOH reacts with the phenols, mineral acids and organic acids to form water and water soluble salts, and water from this reaction is used to remove these salts

3. Reactionsa. 2NaOH + H2SO4------> Na2SO4 + 2H2Ob. NaOH + HNO3------> NaNO3 + H2Oc. NaOH + C6H3(NO2)2OH------> H2O + C6H3(NO2)2Nad. NaOH + C6H3(NO2)3OH------> H2O + C6H3(NO2)3Na

4. Questionsa. How much H2SO4 gets into the washer?b. How does a washer work?

Heat Exchanger

1. Assume saturated stream temperature at heat exchanger inlets2. Steam

a. Low Pressure Steam @ 1.7 bar g b. Medium Pressure Steam @ 12 bar g

3. Cooling Water : a. Supply Temperature 25 *C (max)b. Supply Pressure 5 bargc. Return Temperature 40*Cc. Return Pressure 2.5barg (min)

Other

1. Nitrogen : stored on site, available at 5.0 bar g (measured at 1 atm) 2. Electricial Power :

a. < 250HP @ 440 volts, 3 phase b. Instruments @115V ,single phase

3. Instrument air:a. System pressure 7bargb. Instrument air dew point required -34*C

Questions should be answered

i) the process should be efficient in both raw materials and energy usage (1st)

ii) the technical understanding of the key processes should be so good that the process as a whole can be run in an optimal way(1st)

iii) the plant should meet all current and foreseeable safety and environmental legislation. (2nd)

UTILITIES

Things to research

1. The best conditions for reactiona. Composition of the componentsb. Temperaturec. Pressured. e.t.c