FROM: Joseph C. Leung, Design/Testing Committee Chair

DATE: March 23, 2016 TO: DIERS Membership FROM: Joseph C. Leung, Design/Testing Committee Chair CC: Harold G. Fisher, Chair

SUBJECT: DIERS Round-Robin ERS Design for a Phenol-Formaldehyde Reactor

The proposed design round robin system is based on a chemical reactor carrying out a phenol-formaldehyde reaction with an alkali as catalyst. The scenario is the loss of cooling during the initial heat-up with no mitigation. Phenol-formaldehyde products catalyzed by a base are called resoles.

An invitation is extended to all who would like to participate in conducting a design round-robin to size a reactor vent for this resole runaway reaction. Many organizations participated in the experimental round-robin with the proposed composition and procedure. For the most part the experimental results were quite consistent among the participants. One of these tests, called VSP 2, was chosen as the basis for all participants in this ERS design round-robin.

SCENARIO: Resole reaction with loss of cooling during incipient heat-up and no mitigation available to reduce the effect of the runaway reaction.

ACTUAL COMPOSITION OF EXPERIMENT VSP 2: Formulation % CAS No. Phenol 43.54 108-95-2 Deionized Water 25.90 7732-18-5 Paraformaldehyde 95%, Powder 26.42 30525-89-4 50% Aqueous Sodium Hydroxide Solution 4.14 1310-73-2 Total 100.0 0

VSP2 TEST CELL INFORMATION:  Type: VT3-304-SIL-SN-L-SN  Mass: 32 g based on stainless steel, i.e., the thermal mass of the stir bar Teflon and magnet components were converted to an equivalent thermal mass of stainless steel.  Volume: 111 ml total volume CHEMICAL REACTOR INFORMATION  Inside diameter: 2500 mm  Shell height: 3100 mm  Head type: torispherical o Crown radius to vessel diameter, f = 1.0 o Knuckle radius to vessel diameter, k = 0.1  Total volume: 18.31 m³ (4837 US gal)  Volume of bottom head plus shell: 16.76 m³ (4429 US gal)  The reactor is ASME-coded or equivalent and rated at 50 psig (3.45 barg)

NOTES:  Disregard the reactor mass in the calculations.  Reaction mass is 14000 kg (30864 lb)  Evaluate two effects: o Rupture disc set pressures of 10 and 25 psig (0.69 and 1.72 barg) o Elevation pressure drop in vent pipe  Consider Vent 1 and Vent 2 for this analysis. The total length of these vents is the same, but the vertical and horizontal segments differ.  The discharge is to atmospheric pressure.  This reaction is very exothermic. In the practice of this technology a typical reactor will have jackets, coils and a condenser. The condenser can be used for vacuum reflux during the exotherm and for the subsequent distillation. Some coils and jackets may swing between heating with steam and cooling with water for extra cooling capability.  Assume homogeneous models in the reactor and in the vent during relief.

EMERGENCY VENT:

Sequence Component Vent 1 Vent 2 1 Reactor nozzle height (mm) 150 150 2 Rupture disc assembly height (mm) 100 100 3 Vertical segment length (mm) 1000 5000 4 90° Vertical-to-horizontal elbow Yes Yes 5 Horizontal discharge length (mm) 9000 5000

 The rupture disc has a certified velocity head loss Kr of 1.0.  Two rupture disc set pressures should be considered for the calculations: 10 and 25 psig (0.69 and 1.72 barg)

 The entrance to the nozzle is squared, Kentrance of 0.5.

 The 90° elbow has a long radius, K90LR = 0.18.

Please refer to the drawing below for a view of the emergency vent.

9000 mm

m 5000 mm m

0 0 0 1

100 mm Vent 2 150 mm Vent 1 m m

0 0 0 5

100 mm 150 mm

THE FOUR DESIGN CALCULATIONS:

Set Pressure Vent Vent 2 1 10-psig rupture disc Set 1 Set 2 25-psig rupture disc Set 3 Set 4 ITEMS TO SUBMIT:

Report the following for each of the four combinations of rupture disc set pressure and venting isometrics:  Your choice of maximum turnaround (peak) pressure allowed (psig or barg)  Assumptions made for physical properties  Peak reactor pressure (psig or barg)  Peak reactor temperature (°C or °F)  Peak flow rate (kg/s or lb/s)  Average flow rate through the vent, if available, from the set pressure to the turnaround pressure (kg/s or lb/s)  Mass at turnaround pressure, if available (kg or lb)  Pipe diameter (report nominal pipe diameter, inside pipe diameter and pipe schedule of your choice)  Consider nominal pipe sizes 22, 26, 28, 32 and 34 inches as possible answers. This approach prevents large gaps between 20 and 24 inches, between 24 and 30 inches and between 30 and 36 inches.

THANK YOU ALL. Deadline for Submission: September 30, 2016

Send data or inquiry to: Joseph Leung at the following e-mail: [email protected]

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