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HAZOP Analysis Exercise

Submit report to Assignment Box in the department Thursday 11 Sep, 5 pm

Process Section: Phosphoric Acid Feed Line to the DAP Reactor

Design Intention: Feed phosphoric acid at a controlled rate to the DAP Reactor

Guide Word: No

Process Parameter: Flow

Deviation: No Flow

Causes: (1) No feed material in the phosphoric acid storage tank (2) Flow indicator/controller fails high (3) Operator sets the flow controller too low (4) Phosphoric acid control valve B fails closed (5) Plugging of the line (6) Leak or rupture of the line

Consequences: (1) Excess ammonia in the reactor, leading to... (2) Unreacted ammonia in the DAP storage tank, with

subsequent... (3) Release of unreacted ammonia from the DAP storage tank to

the enclosed work area (4) Loss of DAP production

Safeguards: (1) Existing safeguard is the Flow Indicator.

Actions: (1) Consider adding an alarm/shutdown of the system for low phosphoric acid flow to the reactor

(2) Ensure that periodic maintenance and inspection for valve B are adequate

(3) Consider using a closed tank for DAP storage.

(4) Period maintenance of valve B.

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This process is repeated with other guide word/process parameter combinations then the study continues with the next node in the design. Every process section is evaluated, and the relevant information is recorded in a HAZOP study table.

HAZOP Project

Team: HAZOP Team #N Drawing Number 70-0BP-57100 Meeting Date: 20/08/04 Revision Number: 3

Item No.

1.0 Vessel - Ammonia solution storage tank. Safely contain ammonia feed at ambient temperature and pressure.(Design Intention)

High Level (Deviation)

2.0 Line - Ammonia feed line to the DAP reactor. Deliver ammonia to reactor at y gpm and z psig.(Design Intention)

High Flow (Deviation)

3.0 Vessel - Phosphoric acid solution storage tank. Safely contain acid feed at ambient temperature and pressure(Design Intention)

Low concentration of phosphoric acid (Deviation)

4.0 Vessel – DAP reactor. Contain the reaction at x °C and y psig (Design Intention)

Loss of agitation (Deviation)

5.0 Draw the fault Tree of AMMONIA RELEASES TO WORKPLACE ENVIRONMENT as top event.

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HAZOP Project

Team: HAZOP Team #N Drawing Number 70-0BP-57100 Meeting Date: 20/08/04 Revision Number: 3

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PROCESS INFORMATION (optional)

You may report here a brief process description, process physical data, hazardous properties of materials, assumptions, and any additional information used.

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HAZOP ANALYSIS WORKSHEET (1 for each deviation)

Process Section: Design Intention: Guide Word: Process Parameter: Deviation: Causes: Consequences:

Safeguards:

Actions:

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HAZOP ANALYSIS WORKSHEET (1 for each deviation)

Process Section: Design Intention: Guide Word: Process Parameter: Deviation: Causes: Consequences:

Safeguards: Actions:

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HAZOP ANALYSIS WORKSHEET (1 for each deviation)

Process Section: Design Intention: Guide Word: Process Parameter: Deviation: Causes: Consequences: Safeguards: Actions:

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HAZOP ANALYSIS WORKSHEET (1 for each deviation)

Process Section: Design Intention: Guide Word: Process Parameter: Deviation: Causes: Consequences: Safeguards: Actions: