Alkylphosphines. Storage and Handling Recommendations

Transcription

1 Alkylphosphines Storage and Handling Recommendations

2 2 The Phosphine Specialties Group has been producing phosphine and phosphine derivatives on a large scale for a number of years and the handling procedures have continually evolved. Cytec would like to provide an overview of these procedures for users of our products for a number of reasons. Firstly to facilitate the safety of those who use these products, such as chemical operators as well as warehouse and material handling personnel. Secondly, to ensure that the quality of these products is maintained. larger port that must not be accessed by the user. Two of the 1/4 ports come equipped with Swagelok* needle valves with 1/4 compression fittings with a metal to metal seal, and with a live load packing to protect against thermal cycling and wear. These valves are metal to metal stem seal, and should not be over tightened. The other ports are plugged, but may be configured as per customer request. * Trademark of Swagelok In general alkylphosphine derivatives including mono-, di-, and trialkylphosphines, are strong reducing agents, and will react readily with oxygen. It is for this reason that these products are manufactured, shipped, stored and used under an inert atmosphere such as nitrogen. This inerting procedure ensures the quality of the product by eliminating the chance for the formation of oxidation products at the cost of the active phosphine compound. The oxidation products will not produce the desired reaction. The vessels will have been inerted prior to filling, and will arrive under slight nitrogen pressure (2-3 psi). They may be stored, as received, avoiding extreme temperature variations. The product will keep indefinitely provided the seal and inert atmosphere are maintained. Shipping and Storage Vessels The method by which the product arrives at the customer site depends on the scale of the operation. The vessels range from small quantity (up to 10 gallons) UN approved shipping vessels (Figure 1 displays the UN approved small quantity vessels). Larger quantities would be received in a 100-gallon cylinder. For even larger quantities, ISO containers or rail cars would be used. This bulletin will describe the vessels up to and including the 100-gallon size. Upon receipt of product from the carrier, the cylinder(s) should be inspected for any damage or leaks. Any problems during the receiving procedure should be reported to the carrier and the supplier as soon as possible. These vessels should be isolated while awaiting instructions. Description of Vessels Description of UN Approved Shipping Vessels Small quantities (up to 10 gallons/38 L) will arrive in UN approved shipping vessels. These vessels are 9-inch diameter metal containers of various heights depending on the volume. The top consists of 4 x 1/4 NPT ports and one Figure 1 - Typical UN approved shipping vessels

3 3 Description of 100 Imperial Gallon Cylinders The cylinder used for transportation and storage of organophosphines weighs approximately 360 lbs. (163.3 kg) when empty and measures approx ( cm) high by 2-6 ( cm) diameter. The liquid is filled into the cylinder through a 3/4-14 NPT connection. This filling line has a discharge tube, which goes to the bottom of the cylinder. The vent line is a 1/2-14 NPT connection and does not have a discharge tube connected. The following figures illustrate these points. From 1-10 Gallon Vessels Two methods for the transfer of material from a shipping vessel into the reactor are described here. The method you use will depend on whether the entire contents of the cylinder are to be transferred, or only a portion of the contents. Before starting, ensure that all valves are closed prior to removing valve caps. Transfer of Material Before you are ready to introduce the product into the process it is important that all the transfer lines and reaction vessels be thoroughly purged of oxygen. Cycling through a vacuum and/or pressurizing with nitrogen several times can do this. Transfer lines should be purged with an inert gas (such as nitrogen) for several minutes allowing the flow to continue at a few cc/minute as the connection is made. Figure 3 - Notches placed in the end of the discharge tube Figure 2 - Discharge tube located on the liquid fill line for the cylinder Figure 4 - Top configuration of cylinder (only discharge tube connection installed). This illustrates the 3/4 liquid fill connection for the cylinder. It is connected to a 1 NPT opening on the top of the cylinder and reduced to 3/4 piping using a bushing

4 4 Figure 5 - Vapor line valve and threaded connection Figure 6 - Top configuration of cylinder, both vapor (left) and liquid connections installed. This illustrates the 3/4 liquid fill line (left side) and the 1/2 vapor line (right side). Both are connected to the 1 NPT openings on the cylinder while the 3/4 spare openings have been plugged If the entire contents of the vessel are to be used (Figure 7), a nitrogen line is required to pressurize the cylinder. A second connection from the discharge tube to the reactor will also be needed. When all connections are complete and all lines and reactors are purged the transfer may begin. Figure 8 shows the difference between the discharge tube and nitrogen hook-up. The cylinder should be pressurized typically between 10 and 20 psi (line pressure should be regulated to a maximum of 50 psi) by opening the line valve, then opening the vessel valve. When pressurized, the discharge valve may be opened to begin the transfer of material into the reactor. When the contents have been transferred, the nitrogen flow should continue to blow the lines as clear as possible. Valves should be closed while a small nitrogen flow continues, and a positive nitrogen pressure should remain in the vessel after use (typically 3-5 psig). The vessel may now be disconnected. Transfer lines may still contain traces of organophosphine, and a small amount of material will remain in the vessel. The cylinder should be shipped back to the supplier at this point. Further cleaning is not required. The large port in the top (see Figure 9) is a clean-out and should never be opened. If a portion of the product is to be used for a single run, a transfer manifold similar to the one in Figure 10 may be used to assist with the transfer. We recommend consulting with your safety and engineering departments to ensure company standards are met. (see Figure 10 and Figure 11). Relief Valve N 2 Pressure Indicators To Process Discharge Tube Figure 7 - Schematic for transfer of product from shipping cylinder

5 5 the manifold. This action will blow out the other side of the manifold, back down through the dip tube. Continue this for several minutes, then close the vent valve on the cylinder and then valve B. This action should leave a positive pressure in the vessel sufficient for storing. The manifold may now be disconnected and cleaned. Figure 8 - Shipping cylinder valve configuration, shorter stem for nitrogen hook-up longer stem discharge port Transfer of the product may be done in several ways and is usually dictated by engineering and/or safety standards. Here is a suggestion on transfer of material using the transfer manifold. The transfer manifold should first be connected to the cylinder while a trickle of nitrogen flows through valves A and B (see schematic Figure 11). Once the connection is made, close valve B and open valve C to purge the transfer line. When the purging is complete, close valve C. Figure 9 - Cylinder valve and port configuration. Note large central port is not a user port To transfer product, pressurize the cylinder through the discharge tube by opening valves A and B and then the vessel discharge tube valve. When the cylinder has been pressurized, close valve A, then slowly open valve C. The material should begin to flow. When the transfer is complete, close valves B and C and open valve A. Slowly open valve C, this will drain the line to the process, continue this action for several minutes. When the line is blown clear, close valve C. Open the other valve (connect to vent) and slowly open valve B on Figure 10 - Transfer manifold connected to shipping vessel

6 6 To Cylinder B From 100 Imperial Gallon Cylinders N 2 A Check Valve Pressure Indicator To Process Figure 11 - Schematic of transfer manifold The transfer of product from the cylinder can be done using various methods. Outlined below are some guidelines for transferring material and the equipment used to do it. When transferring the product from the cylinder the inert gas used to pressurize the cylinder (typically nitrogen) is connected to the 1/2-14 NPT connection located on the top of the cylinder. The 1/2 connection should always be considered the vapor line unless specifically identified to the contrary. When pressurizing the cylinders it should be noted that they are rated to a working pressure of 240 psig but the fittings, which we use (i.e. valves and piping) are rated to 150 psig. A pressure of 10 to 30 psig is usually adequate for transferring material. Please note that if the nitrogen supply pressure could exceed 150 psig, then the product cylinder should be protected by a safety relief valve set at a maximum of 140 psig. The 3/4-14 NPT connection is used to transfer the liquid from the cylinder to the process. The nitrogen applied through the 1/2-14 NPT vapor line pushes the liquid up through the discharge tube. C Figure 12 illustrates the way the equipment should be set-up. The circles on the sketch represent pressure indicators used to determine if the product is moving from the cylinder. When the valves are opened, a small differential of 3-4 psig will indicate the movement of materials. Once all the connections have been made, the valves should be left closed and lines pressurized to 10 psig and checked for leaks using leak detection compound. Once this is complete and any leaks have been fixed, the lines should have the nitrogen bled off and the product is ready for transfer. Required Materials Carbon steel can be used for transferring liquid organophosphine products, but for long-term service or extended use, we suggest using 316SS. This material will have a longer service life over the carbon steel, and will not contaminate the product with rust. The valves Cytec uses are the 1/2 and 3/4 Series 3600 ball valves made by Neles-Jamesbury. The one end is a screwed connection for the N 2 To Process Relief Pressure Indicators Cylinder 1/2 3/4 Discharge Tube Figure 12 - Schematic, system for transfer of material from cylinder

7 7 Figure 13 - Cylinder with transfer fittings attached to vapor and liquid fill lines Figure 14 - Attaching nitrogen supply Figure 15 - Installing gasket customer and butt-welded at the other end coming from the cylinder. More details can be provided at the customer s request. The fittings depicted in Figures are the type Cytec uses for transferring material. Other fittings can be used in place of these, however, these have been chosen as preferred fittings because of their quick connect ability and simple operation. The material of construction is 316SS and the gasket material is encapsulated Teflon*. Further details are available at the customer s request. Figures 13 to 17 represent the set-up of a cylinder for transfer using the recommended materials. The plugs have been removed from the valves and the transfer fittings installed using Teflon tape on the threads to provide a good seal. The connection at the top of Figure 13 is the liquid fill/discharge connection and the one at the bottom is the vapor connection used for pressurizing the cylinder. Spill Management In the event of a spill there are several possible solutions to resolving the problem. These include the use of foam, sand and inert absorbent clay. The used absorbent should be collected and placed in a sealable container and sealed under an inert atmosphere. The material should then be sent out to a waste disposal facility. If a fire occurs on a valve, use foam to put out the flame. This will ensure that the seals will not be destroyed which could cause further loss of material. If the material gets on the outside of the cylinder, it will act as a paint stripper causing the paint to bubble up. Customers should scrape the material off and collect it in the same manner as the absorbent (i.e. under an inert atmosphere and sealed container). Cylinders that have paint damage are repaired on arrival back at the Cytec facility. *Registered trademark of E.I. dupont de Nemours & Co.

8 8 Figure 16 - Securing nitrogen connection Figure 17 - Final set-up for product transfer Health and Safety Before handling any of these materials, read the corresponding Cytec Industries Inc. Material Safety Data Sheet (MSDS) for health and safety data. custinfo@cytec.com Worldwide Contact Info: US Toll Free: Tel: (+1) Disclaimer: Cytec Industries Inc. in its own name and on behalf of its affiliated companies (collectively, Cytec ) decline any liability with respect to the use made TRADEMARK NOTICE: The indicates a by anyone of the information contained herein. The information contained herein represents Cytec s best knowledge thereon without constituting any express or Registered Trademark in the United States implied guarantee or warranty of any kind (including, but not limited to, regarding the accuracy, the completeness or relevance of the data set out herein). and the or * indicates a Trademark in Nothing contained herein shall be construed as conferring any license or right under any patent or other intellectual property rights of Cytec or of any third the United States. The mark may also be party. The information relating to the products is given for information purposes only. No guarantee or warranty is provided that the product and/or information is registered, the subject of an application adapted for any specific use, performance or result and that product and/or information do not infringe any Cytec and/or third party intellectual property rights. for registration or a trademark in other The user should perform its own tests to determine the suitability for a particular purpose. The final choice of use of a product and/or information as well as the countries. investigation of any possible violation of intellectual property rights of Cytec and/or third parties remains the sole responsibility of the user Cytec Industries Inc. All Rights Reserved SPT-151-C-EN-WW-02D