100 Safety Systems

Question 1

Name all valves activated on an MRE-101 general trip, and the action taken (opens/closes).

Answer 1

Closes, Sv101, Fcv101, Sv102, Fcv102, Fcv103, Sv11.

Question 2

List 3 trips for LTDC reactor and why.

Answer 2

HHH temp >80C to protect reactor and downstream equipment from heat damage.

HHH vent flow >1300 scfm to protect GTOs from excessive vent load and high temperatures.

HHH pressure >70 psi
HHHH pressure >80 psi
protects reactor from high pressure which could damage equipment, cause inefficient reaction and result in a release of hazardous chemicals to atmosphere.

Question 3

Will the following activate a reactor general trip? High O2 concentration in vent gas.

Answer 3

Yes, both A13-1 & A13-2 at 9.5% O2

Question 4

Will the following activate a reactor general trip? Reactor HHH level.

Answer 4

Yes, L111 @ 95%

Question 5

Will the following activate a reactor general trip? Reactor LLL level.

Answer 5

Yes, L111 @ 20%

Question 6

Will the following activate a reactor general trip? Reactor HHH temp.

Answer 6

Yes, T111 @ 80C

Question 7

Will the following activate a reactor general trip? Reactor LLL temp.

Answer 7

No

Question 8

Will the following activate a reactor general trip? Reactor HHH vent flow.

Answer 8

Yes, F112 @ 1300 scfm

Question 9

Will the following activate a reactor general trip? Reactor LLL vent flow

Answer 9

No

Question 10

Will the following activate a reactor general trip? Reactor HH pressure.

Answer 10

No

Question 11

What interlock condition closes N7 to direct feed spargers and at what value is it activated?

Answer 11

P111 @ 70 psi HHH

Question 12

What interlock condition closes the propylene level controller and at what value is it activated?

Answer 12

P114 @ 52 psi HH

Question 13

If an LTDC crude EDC pump shuts down, what valve closes?

Answer 13

SV111

Question 14

What could result if water is left in the Direct Reactor at startup?

Answer 14

Chlorine will react with the water to form acid which will eat away at the reactors stainless steel cladding.

Question 15

Why is it important to have a normal Direct Reactor EDC level during operation?

Answer 15

A high level will cause high vent pressure and fill dilution space preventing O2 from diluting and possibly causing an explosive atmosphere in vent header.

A low level will halt thermosiphon and prevent EDC from cooling causing heat buildup in the reactor.

Question 16

Which feed is introduced to the LTDC reactor first?

Answer 16

N7>EDC>Ferric>Chlorine>Ethylene

Question 17

During startup, if the Direct Reactor begins venting excessively, what should be suspected?

Answer 17

Ethylene to chlorine ratio is too high.

Faulty O2 analyzer causing F107 to feed to much N7.

Faulty reading on F112.

Question 18

During startup, if the Direct Reactor begins venting excessively, what should be suspected?

Answer 18

Ethylene to Chlorine feed ratio too high.

Faulty A13 or F107 causing too much N7 purge flow.

Faulty F112 reading.

Question 19

During idle, what must be kept on the LTDC feed spargers?

Answer 19

Nitrogen

Question 20

How do you respond to high O2 in the chlorine supply?

Answer 20

Increase F107 flow

Contact C/A

Verify A13 is working properly

Question 21

Normal chlorine feed pressure in directs is ________ psi.

Answer 21

55 psi

Question 22

What is the normal range of ethylene feed pressure to the reactors?

Answer 22

75 psi

Question 23

What is the uncorrected consequence of high O2 in the chlorine supply to the LTDC.

Answer 23

Possible explosive atmosphere in the directs vapor space.

Question 24

What is the uncorrected consequence of high free chlorine in the direct reactor product?

Answer 24

More acidity in formed in the wash train resulting in more caustic used and more salts to CU treatment and MCL 231/232

Question 25

Give two causes of low excess chlorine in the LTDC product.

Answer 25

Faulty A11 Faulty F103

Question 26

Give two causes of high O2 in the reactor vent.

Answer 26

A13 incorrectly reading low O2 High O2 concentration in chlorine from C/A

Question 27

What action is taken if chlorine pressure exceeds 75 psi.

Answer 27

C/A begins neutralizing chlorine

Question 28

What action is taken if chlorine pressure is less than 50 psi?

Answer 28

Contact C/A. Reactor placed in flow controls trips at 47 psi

Question 29

What could be the consequence if you get low flow on F121?

Answer 29

EDC is not coming from directs at target production rates.

Question 30

What correction should be made if DW flow is low to the 2nd stage acid wash tank?

Answer 30

Adjust F122 to correct flow. Verify interface level in MTK106

Question 31

List two possible causes for low NaOH flow to the wash train.

Answer 31

Pump failure F124 malfunction High ethylene to chlorine ratio

Question 32

What is the incorrect end consequence of a high steam flow on F633 A/B?

Answer 32

Over-boiling Acid Stripper feed causing excess water in the overhead which will have to be restripped.

Question 33

What is the uncorrected consequence of low steam flow on F633 A/B

Answer 33

Under-boiling will occur and edc will exit Acid Stripper bottoms to Cu Treatment yeilding hazardous mud waste.

Question 34

Give a cause of high LTDC reactor pressure.

Answer 34

P112 reading false low Reactor feeds out of ratio, making excess vents Loss/restriction of cooling water Fouled MHE 105/106

Question 35

Name an unintended consequence of high temp on the direct reactor.

Answer 35

Higher concentration of impurities in EDC product. Higher vent pressure Potential to damage equipment

Question 36

What is the purpose of P121?

Answer 36

To hold back pressure on the wash train which keeps its psi higher than the directs and keeps gases entertained in liquid

Question 37

What’s should you do if you find phased EDC in the ACID we stripper feed?

Answer 37

Cut feed and steam. Realign min flow to above packing. Circulate water and look upstream for issues.