CECA -Adsorbents Handling Procedures

PROCEDURE

CECA ADSORBENTS FOR THE OIL AND GAS INDUSTRY

HANDLING PROCEDURES

CECA Adsorbents Handling Procedures

CONTENT :

INTRODUCTION BASICS OF ADSORPTION STORAGE INSTRUCTIONS HANDLING INSTRUCTIONS VESSEL LOADING INSTRUCTIONS VESSEL UNLOADING INSTRUCTIONS DISPOSAL OF CECA ADSORBENTS


INTRODUCTION

BASICS OF ADSORPTION

This document details CECA requirements for the handling of adsorbents (molecular sieves, activated alumina, silica gel) and ceramic balls in process units.

In gas and liquid separation applications, the aim is to selectively retain molecules that form low energy bonds with the adsorbent internal structure. This phenomenon is called physisorption and follows adsorption isotherms. It is exothermic (it releases energy in the form of heat).

All the information and recommendations enclosed should be well understood in order to optimize the loading, unloading and disposal operations, and to perform them safely. This document is for the sole internal use of CECA adsorbents customers. It is confidential and not to be disclosed to any third party without CECA explicit consent in writing.

To be efficiently adsorbed, the polar molecules must be small enough to enter the cavities of the adsorbent via their pores. The diameter (or the size distribution) of the pores and cavities depend on the type of adsorbent, which is therefore chosen depending on the application and the molecules to be separated. Typical adsorbents are available in the form of 0.5 to 5.0 mm beads or pellets. They are loaded in vessels and used as fixed bed.

Do not hesitate to contact us for any question you may have : CECA S.A., Molecular Sieve Department Dynamic Applications Tel : +33 1 49 00 38 19 Fax : +33 1 49 00 38 03 Email : [email protected]

The impurities in the treated stream saturate the adsorbent bed generally within a few hours or days. By changing the adsorption equilibrium conditions (lower pressure, higher temperature or both), the adsorbed molecules can be desorbed from the active sites, and the adsorbent can recover most of its original adsorption capacity: it is “regenerated”.

Introduction


STORAGE INSTRUCTIONS

HANDLING INSTRUCTIONS

CECA adsorbents are shipped in air-tight, non returnable steel drums or semi-bulk bags (called “big bags” in the following). See our Standard Offer for Packing, Marking and Expedition for details.

Before handling CECA adsorbents, read the corresponding Material Safety Data Sheet (MSDS) for the up-to-date safety, handling and regulatory information.

In all cases we recommend to warehouse the pallets indoor in order to prevent them from bad weather conditions (rain, sand storm, etc.), direct sun and ground humidity.

CECA adsorbents are silica gels, aluminas or alumino-silicates (zeolite-based molecular sieves). They are chemically similar to ordinary clays and are therefore inert under normal handling conditions. They exhibit no vapour pressure and have no flammable constituents.

Outside storage is not recommended, in particular for big bags. Should indoor storage not be feasible, the drums or big bags pallets would have to be protected by waterproof tarps and be isolated from the ground. In the case of big bags, outside storage has to be limited, in all cases, to short periods (for instance just before loading the vessels). The drums can be stored up to 5 years under cover. Big bags cannot be stored for more than 2 years, even under cover. For longer storage durations, we recommend to sample and analyse the products, in order to make sure they are still fit for use. These recommendations are general and may slightly differ depending on the product type, packaging, storage location, etc. In any case, ask CECA to make sure your storage conditions meet our requirements.

The main potential serious hazard is related to non (or poorly) regenerated adsorbents desorbing hazardous species (H 2S, etc.) after unloading of the vessels. This scenario and how to avoid it is described in CECA Unloading Procedure. CECA adsorbents are extremely powerful desiccants. They remove water from any substance they come in contact with. As adsorption is exothermic, it can cause burns to a sweating skin. Gloves must be worn while handling CECA adsorbents. No adsorbent dust must be inhaled or allowed to come in contact with eyes. The use of dust mask, goggles, and Breathing Apparatus systems, if in confined space, are mandatory. Excessive or severe handling can cause some dusting.


The statements, technical information and recommendations contained herein are believed to be accurate as of the date hereof. Since the conditions and methods of use of the product and of the information referred to herein are beyond our control, ARKEMA expressly disclaims any and all liability as to any results obtained or arising from any use of the product or reliance on such information; NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, WARRANTY OF MERCHANTABILITY OR ANY OTHER WARRANTY, EXPRESS OR IMPLIED, IS MADE CONCERNING THE GOODS DESCRIBED OR THE INFORMATION PROVIDED HEREIN. The information provided herein relates only to the specific product designated and may not be applicable when such product is used in combination with other materials or in any process. The user should thoroughly test any application before commercialization. Nothing contained herein constitutes a license to practice under any patent and it should not be construed as an inducement to infringe any patent and the user is advised to take appropriate steps to be sure that any proposed use of the product will not result in patent infringement. See MSDS for Health & Safety Consideration

CECA

89, boulevard National 92257 La Garenne-Colombes Cedex - France cecachemicals.com

Storage & Handling 1/1


VESSEL LOADING INSTRUCTIONS

These instructions detail the standard loading method. Special methods such as dense loading or pneumatic loading are not discussed here.

1/ REQUESTED EQUIPMENT 1.1/ Area Enough space is needed around the vessels to store the drums or big bags. As a reminder, ground surface 2 for 1 pallet (4 drums or 1 big bag) is about 1m . Moreover, some space is necessary for the loading process : filling the hopper, crane and forklift manoeuvres, etc. 1.2/ Hopper and loading system Except for the bottom ceramic balls (see § 5.3/below), the products are usually loaded via a hopper. In the case of drums, it is recommended to first pour a few drums in the hopper, and to lift the hopper with a crane (the hopper must be equipped with lifting hooks).

Loading drums one by one is not recommended as the quantities involved are important. Big bags can also be first poured in a hopper, or they can alternatively be lifted directly. See Figures 1 and Figure 2 below. When a hopper is used, its capacity and resistance must comply with the requested use (1 pallet = 4 to 5 drums = 500 to 700 kg) or 1 big bag (800 to 1000 kg). The bottom opening must be large enough to prevent clogging. A diameter of 150 mm is a minimum (300 mm is recommended). The hopper valve must be easy to operate and must be able, if needed, to quickly stop the product without crushing the beads or pellets. A guillotine valve is usually the best compromise. When big bags are used and directly lifted, their bottom short sleeve must be opened with care and the flow of product must also be controlled.

Loading 1/7

CECA Adsorbents Handling Procedures is reduced from time to time, in order to always have between 600 and 1000 mm from the bottom of the sleeve to the top of the bed. The sleeve must also be equipped with a rope attached to its end. This rope is used to direct the product flow inside the vessel.

poured products Cone-bottom shaped hopper valve rope sleeve

Figure 1

lifted big bag

Example of an equipped hopper

rope 1.3/ Crane

sleeve

A crane is required to lift the filled hopper (or the big bags) from the ground up to the vessel manway. 1.4/ Forklifts

Figure 2

Attached to the bottom of the hopper, or to a coneshaped system fixed to the manhole (in particular when big bags are lifted), a long sleeve prevents the adsorbents from falling from too high. It is a flexible cylinder-shape piece, which diameter is at least equal to the diameter of the bottom o pening of the hopper or cone-shaped system. The sleeve can be made from various flexible, resistant materials, such as any cloth, plastic films, flexible pipes, constructions conducts, etc. Its length

Forklifts are used to carry the drum or big bag pallets. Two forklifts is a minimum : one to bring full drums from the storage area to the hopper filling area, and another to bring empty drums on pallets to another storage area. 1.5/ Hopper filling area / Scaffolding platform When drums have to be loaded in a hopper, a secured platform is convenient to handle the pallets and to fill the hoppers securely (see § 4.6 for details). Note: The platform can be replaced by a hole made in the ground, in which the hopper is loaded. In this case drums are simply rocked on the hopper.

Loading 2/7

CECA Adsorbents Handling Procedures 1.6/ Safety equipments

1.12/ Tarpaulin - Plastic cover

Safety / PPE (Personal Protective Equipment) outfits and fittings have to be available and used according to the plant’s safety rules. Contact CECA in case you have any question or any doubt. Equipment typically includes :

If sudden rain or snow occurs during the loading operation, it is important to be equipped to protect the product from exposure (hopper and vessels). For each vessel, at least one plastic cover, to be put on the manhole, is requested. Tape is needed to fix it tightly.

Helmet, gloves, safety shoes, dust mask, harness, goggles, clothes with long sleeves, Breathing Apparatus systems, portable oxygen detector.

1.13/ Lighting equipment Lights (flashlights, spotlights) are needed to see inside and inspect the vessels.

1.7/ Wood boards and ladder 1.14/ Other useful tools A ladder (long enough to go from the top manway down to the support grid) is necessary. At least 3 wood boards are needed in order to put up the ladder and walk on the bed during the levelling steps.

Cutters, scissors, adhesive tape, etc.

2/ UTILITIES Note : a winch can also be used instead of a ladder. 1.8/ Rake A rake (or a “rake-type” tool) is needed for bed levelling operations.

No specific utilities are required to perform CECA adsorbents loading. However, a source of inert dry gas (typically nitrogen) is highly desirable in order to purge and remove atmospheric air from the bed after loading.

1.9/ Rulers 3/ MANPOWER Rulers are useful to measure the level of product in the vessel from time to time, and therefore control its homogeneity all around the vessel after a levelling operation. Rulers have to be long enough. If they cannot be easily provided, they can be replaced by scaled ropes or by tape-measures. Note : an alternate solution is to graduate the vessel wall in several locations on its circumference and all along its height while the vessel is empty (for example using a chalk). 1.10/ Stainless yarn Stainless yarn is used when wire mesh screens are supplied in several pieces that have to be partially overlapped and tied together (usually for large vessel diameters). Note : blind rivets can also be used. 1.11/ Spare screens For each kind of wire mesh screen in the vessel, it is necessary to have spares (and / or spare parts). This is true essentially for change outs, in order to be able to immediately replace former screens if damaged, or at least to repair them.

In order to proceed securely, we highly recommend to have at least 7 workers per team. We also suggest the following dispatch : Crane : Forklifts : Hopper filling / big bag preparation : Filling operation / levelling / supervision :

1 2 2 2

The number of needed teams depends on the loading conditions (day shift, 24hr/day, several vessels loaded at the same time, etc.) Loading supervision can sometimes, upon request and commercial agreement, involve a CECA representative. In that case, the CECA representative is only responsible for indicating what has to be done and what has to be avoided. He / She has no hierarchical link with the loading team, and it is essential that he / she directly reports to a company official loading supervisor who organizes the work in practice. CECA representative can, at any time, instruct to stop the loading operation, upon circumstances which to his judgment, could result in unsafe or improper performance.

Loading 3/7

CECA Adsorbents Handling Procedures 4/ PRELIMINARY OPERATIONS & SPECIAL RECOMMENDATIONS

4.3/ Grid – wall sealing Due to thermal expansion (especially in the case of a TSA - Temperature Swing Adsorption system), the support grid and the vessel show a little gap. In or der to prevent any product leakage, it is paramount to ensure a perfect sealing between the grid and the vessel wall. This is usually done with several layers of ceramic rope inserted in the gap.

4.1/ Typical vessel layout See Figure 3 for a typical vessel layout (may slightly differ from a unit to another) In some cases, a V-wire grid type (by “Johnson Screens” and others) is used instead of the support grid and bottom wire mesh screens. 4.2/ Wire mesh screens The wire mesh screens that are installed over the grid and / or below the top ceramic balls must be new or damage free. For large vessel diameters, they are usually supplied in several pieces that need to be partially overlapped (5-10cm) and well tied together with the use of stainless yarn, wire or blind rivets.

Ceramic rope sealing

Inlet nozzle with rectangular slots showing suitable open area, and covered with 20 mesh screen*.

Bottom of distributor

Baffle plate with 4 holes

600 mm mini. Top of products Ceramic balls 1”

Floating screen

Alumina or Silica gel guard bed layer (when applicable)

Molecular sieves layers

20 mesh screen* (+ 15 cm overlap)

Manhole / dump port

Ceramic balls layers

10 mesh screen*

Ceramic balls layers 3 mesh screen* Fiber rope around the whole circumference (gasket / tightness)

Main support grid

I-beam supports

20 mesh screen* Optional and strongly recommended : Hold-down ring all around the vessel circumference, to reliably maintain the bottom screens and ensure a suitable tightness

* US size N° 20, 10 and 3 Stainless Steel Mesh Screen

Figure 3

Loading 4/7

CECA Adsorbents Handling Procedures In addition to that, the upper 20 mesh screen over the grid must be larger than the vessel diameter in order to provide a 10-15 cm overlap up the wall. A hold-down ring that maintains the mesh screen is recommended.

disposal of empty packaging has to be planned as well, in order not to clutter the loading area. The quantity of big bags and / or drums corresponding to a given vessel load must be stored in a dedicated area near it. They must be arranged in the order of loading. When loading a hopper with drums using a platform, bring the pallet on the platform with a forklift. Drums are brought one by one to the tilting area of the scaffolding. They are opened and poured into the hopper. Empty drums are brought back on the pallet, and the pallet with empty drums is brought to the specific storage area by the second forklift.

Mesh screen with overlap and a hold-down ring

4.4/ Clean and dry vessel Before the loading starts, the vessel and all internals must be perfectly clean and dry (air movers or dry gas blowers may have to be used). It is extremely important to make sure there is no remaining dead volume of water. 4.5/ Side manhole blind The side manhole can sometimes represent a significant volume. It is recommended to insert a blind with a few tiny hole for pressure equalization. (The holes must be small enough to prevent beads or pellets to go through.) See Figure 4.

Example of a platform

4.7/ Prevention from humidity or air In order to prevent adsorption of atmospheric water on the adsorbents, it is important not to open the drums before being ready to pour the product into the hopper. Several minutes of exposure during loading does not cause significant water pick up. Ceramic balls

During the night, manholes have to be hermetically closed. If possible, it is recommended to flow dry air or nitrogen into the vessels.

Grid and screens

Figure 4

5/ LOADING OPERATION

4.6/ Management of drums and big bags It is very important to foresee and organize the transfer of the drums and big bags from their main storage to the loading operation area. Removal /

The following procedure is made of standard suggestions and advice that must be adapted to each case. The operation must always conform with site safety rules. We consequently ask you to read this procedure carefully, and to contact us if any question arises.

Loading 5/7

CECA Adsorbents Handling Procedures 5.1/ Hopper / big bag lifting The hopper (or the big bag) filled with products is lifted by the crane up to the top level of the vessel; right above the manhole.

It is necessary to first put the ceramic balls all around the circumference of the vessel, in order to well maintain the mesh screens and ensure a good seal thanks to the 20 mesh screen overlap. Top ceramic balls can also be loaded with buckets.

Ceramic balls lying on the mesh screen

5.4/ Bed levelling Bed levelling is a crucial operation that needs to be performed regularly and neatly in order to have homogeneous layers of products. Hopper and big bag lifting Here a second hopper with a long sleeve is already installed on the vessel manhole

5.2/ Adsorbents loading The product is carefully released by slowly opening the hopper valve (or the bottom of the big bag), and flows into the sleeve. The flow must be controlled (in order to prevent clogging of the sleeve) and directed (thanks to the rope, in order to well spread the products and avoid a too large slope). When the hopper is empty, it is brought back to the ground level for the next operation. It is highly recommended to prepare and continuously fill out “loading sheets” with the lot numbers, timing, product height (see § 5.4), etc. 5.3/ Ceramic balls loading It is possible to load the bottom ceramic balls from the top, like the adsorbents. However, as they are bigger (typically up to 1/2 inch diameter) and denser, the flow must be very well controlled in order to avoid damaging the balls and the bottom mesh screens. When it is possible, bottom ceramic balls are preferably loaded using a rope and buckets (or directly through the side manhole when there is one).

The number of levelling operations is a function of the number of loaded grades, height of the layers, vessel diameter, etc. As a minimum, it has to be done for each layer of products; but is usually also performed at intermediate levels. The person in charge, who enters the vessel must wear all the required safety equipments (see § 1.6). He / She has to stand on wood boards and levels the bed using a rake or a rake-like tool. After the bed is considered flat and well levelled, the height between the top of the bed and the manhole is measured and compared to the forecasted one. 5.5/ Top 20 mesh screen The 20 mesh screen with overlap is installed on top of the adsorbents (below the top ceramic balls, see Figure 3). It is important not to tie this mesh screen with the vessel. If any internal such as a purge pipe (or a feed pipe or temperature probes) has to go through the 20 mesh screen, it is requested to make a hole of the same diameter in the screen, and to surround the internal with a cone-shaped piece of 20 mesh screen. This piece must be attached to the 20 mesh screen, but not to the internal. It is recommended to do this work once the screen is in the vessel.

Loading 6/7


Operators equipped for internal operation

5.6/ Waiting for start-up After the loading and before the start-up, the oxygen must be removed from the vessel, typically by a nitrogen purge. Often the available flow-rate of nitrogen is too low to provide the required turbulent flow. The vessel has to be pressurized and depressurized several times with nitrogen (preferably downstream in order not to lift the bed) – contact CECA if this is not feasible. If the unit is loaded and not to be put in service before several weeks or months, it is recommended to isolate the vessel from the rest of t he process. This will prevent trace contaminants and moisture from being introduced into it. If the above procedures are followed, it is not be necessary to regenerate the beds prior to start-up. Here also a small nitrogen pressurization can help ensure no outside moisture would come in.


The statements, technical information and recommendations contained herein are believed to be accurate as of the date hereof. Since the conditions and methods of use of the product and of the information referred to herein are beyond our control, ARKEMA expressly disclaims any and all liability as to any results obtained or arising from any use of the product or reliance on such information; NO WARRANTY OF FITNESS FOR ANY PARTICULAR PURPOSE, WARRANTY OF MERCHANTABILITY OR ANY OTHER WARRANTY, EXPRESS OR IMPLIED, IS MADE CONCERNING THE GOODS DESCRIBED OR THE INFORMATION PROVIDED HEREIN. The information provided herein relates only to the specific product designated and may not be applicable when such product is used in combination with other materials or in any process. The user should thoroughly test any application before commercialization. Nothing contained herein constitutes a license to practice under any patent and it should not be construed as an inducement to infringe any patent a nd the user is advised to take appropriate steps to be sure that any proposed use of the product will not result in patent infringement. See MSDS for Health & Safety Consideration

CECA


Loading 7/7


VESSEL UNLOADING INSTRUCTIONS

1/ SAFETY Unloading adsorbents from a process vessel requires a good knowledge of the application and a thorough understanding of the possible hazards. Most of the time, toxic and/or explosive substances are present in the vessel at the end of the process operation (including after the last regeneration). This can be the regeneration medium itself (fuel gas, etc.), heavy hydrocarbon deposit (coke), or toxic adsorbed molecules (H2S, etc.) in some applications, when the last regeneration is not complete or not homogeneous. In any case safety requires absolute caution. 1.1/ Safety equipments and concerns Safety / PPE (Personal Protective Equipment) outfits and fittings have to be available and used according to the plant’s safety rules. Contact CECA in case you have any question or any doubt. Equipment typically includes : Helmet, gloves, security shoes, dust mask, harness, goggles, clothes with long sleeves, Breathing Apparatus systems, portable oxygen detector. Before any entry in the vessel, the inside has to be checked with an appropriate device to be lower than 20% of the Lower Explosive Limit (LEL).

Grounding of all equipments is recommended, including trucks (for vacuum unloading). However, static sparks may still occur because of nonconducting containers or other materials. CECA adsorbents are silica gels, aluminas or alumino-silicates (zeolite-based molecular sieves), chemically similar to ordinary clays. As fresh materials they are chemically inert under normal handling conditions, exhibit no vapour pressure and have no flammable constituents. However, used adsorbents have been exposed to liquid or gaseous materials containing traces of other pr oducts, such as saturated and unsaturated hydrocarbons, coke or sulphur compounds. These products may be toxic, flammable or explosive. When exposed to air or rain, they may heat up or be released in the atmosphere. It may happen that during unloading, the adsorbents start to burn. In this case, all operation must be stopped immediately by trained and equipped firefighters. Note : This is the only case which allows to spray water on (non vessel flooded) unloaded adsorbents. Spraying water on dry adsorbents can release all the other adsorbed molecules, potentially toxic, that would remain in the material.

Unloading 1/3

CECA Adsorbents Handling Procedures 1.2/ Last Regeneration Before being unloaded, the adsorbents must be properly and completely regenerated in order to remove as much adsorbed compounds and deposits as possible. Use the same regeneration procedure as usual, unless you have clues or evidence that it is not reliable enough to desorb all impurities. In this case, or if the usual regeneration gas is not available, contact CECA. 1.3/ Purge and deactivation After the last regeneration, adsorbent beds have to undergo a special treatment to remove the last traces of impurities still present. One of two treatments are usually implemented : nitrogen purge or water flooding. It is not always possible to choose between the two as this is subject to constraints (nitrogen availability, type of insulation, etc.) Furthermore, it is important to understand that these 2 methods are not equivalent (they do not act the same way) : - Nitrogen purge removes the process fluid that is still in the vessel, but does not desorb the molecules still in the pores. It is a vessel purge only, preferentially used for the cleaner applications (natural gas drying, etc.) that do not involve too reactive or toxic substances. - Water flooding removes the process fluid but also completely desorbs each and every adsorbed molecule (which are displaced by water molecules). This is an adsorbent deactivation process that is preferentially used in case of reactive / toxic streams involving hazardous adsorbates. In case of poor regeneration (too low flow-rate, channelling issues, etc.), some hazardous molecules (such as H 2S and others) can stay in the adsorbents porosity. If the material is directly unloaded and then exposed to air and / or moisture, it can burn or be released, leading to dangerous situations. Nitrogen purge : This method is the most common, and is generally faster than water flooding as it is not required to dry the unit afterwards. Its main drawback is the use of large quantities of nitrogen, which is sent to the flare. After the last regeneration cooling step, totally isolate the vessel, and depressurize down to atmospheric pressure. Install blind flanges on every pipe, except to the flare and on a sample tap at the bottom of the vessel, which has to be connected to the nitrogen network. Start the purge by flowing nitrogen through the bed and direct the outlet to the flare. The nitrogen flow-rate must be sufficient to

avoid channelling. Minimum flow-rate and duration of the purge can be estimated by your CECA representative. It must be maintained until the gas going to the flare reaches 20% of the Lower Explosive Limit (LEL). Measurement is usually done at a tap on the flare line, using an appropriate analyser. If the nitrogen availability is too low to provide the requested flow-rate, the alternate solution is to perform this purge by successive pressurizations and depressurizations of the vessel. In that case the flare line is closed, and only the nitrogen valve is opened. Gas fills the vessel till the pressure stabilizes at network pressure. The valve is then closed and the flare line is opened, so that the vessel depressurises through it. Once the pressure is stabilized, the flare line is closed again and a new cycle starts. Usually 3 to 5 pres. / depress. steps are required to obtain less than 20% LEL. Water flooding : Water flooding is used when nitrogen is not available, or when there is a risk that hazardous substances are still imprisoned in the adsorbents’ porosity. Note : water flooding cannot be used in case of internal insulation (as it would damage the casting). Vacuum unloading can also be difficult to proceed, especially if a lot of fines is present. After the last regeneration cooling step, totally isolate the vessel, and depressurize down to atmospheric pressure. Install blind flanges on every pipe, except to the flare and on a sample tap at the bottom of the vessel, which has to be connected to the water network. Slowly fill the vessel with water. A fast temperature increase will be observed as the water comes into contact with the regenerated adsorbents. This is a normal non hazardous phenomenon which can be somehow controlled by the vessel filling rate. Fill the vessel until the adsorbents and the ceramic ball layers are totally flooded by water, but be careful not to overfill and flood the flare line (the water height can be estimated from a flow-meter and / or a differential pressure gauge). Plug a flexible pipe to the tap and send all the water to the waste water treatment station. In the vessel, adsorbents and ceramic balls are soaked, and ready for unloading. Note : For special cases involving hazardous substances, that cannot be water flooded, the regenerated adsorbents have to be unloaded into special metal containers with a bo ttom tap connected to water and a top tap connected to a vent line and to

Unloading 2/3

CECA Adsorbents Handling Procedures the flare. A water flooding process can therefore be implemented outside of the vessel for each container.

2/ UNLOADING All internals must be removed from the adsorbent bed (temperature probes, sampling devices, etc.) After having performed the operations described at chapter 1.2/ and 1.3/, the vessel can be opened and the unloading can start.

Gravity unloading : If gravity unloading is chosen, the bottom side manway (or the dump port) is carefully opened to let the product flow. A special cone-shaped piece of metal or wood is put below the manway to direct the flow into the bin or big bags. The flow is controlled by adjusting the manway opening. The product flow is important at the beginning, and slowly decreases. After some time, no more material goes out of the vessel, and it is necessary to complete the unloading manually, using rakes.

Top 1” ceramic balls and mesh screen must be first removed by the top manway (See chapter 1.1 for safety equipment). Sometimes 1” ceramic balls and mesh screen are not removed and go down in the vessel as adsorbents are unloaded by through side manway. In this case, a hook-type device should be used to retain the top screen prior to unloading the bed, in order to prevent it is pulled down and block the outlet.

When all the used adsorbents are out of the vessel, the bottom ceramic balls are unloaded manually. If they are to be reused, the different sizes can be separated by sieving.

Used material can be removed either by pneumatic unloading (vacuum unloading), or by gravity unloading.

Before reloading of fresh adsorbents, carefully and thoroughly dry the vessels, piping and internals, (including the ceramic balls). Fresh material should avoid any contact with remaining moisture

When the bottom ceramic balls are unloaded, check the bottom support grid and the mesh screens (or the V-wire screen) to make sure they can be reused or need to be repaired or changed.

Pneumatic unloading : If a pneumatic truck is chosen, the adsorbents must be dry. A flexible pipe is put into the vessels and sucks the products under vacuum. Most of the time it is necessary that one person remains in the vessel to direct the flexible pipe. Used adsorbents are then sent to a bin or to empty big bags. The used material is often broken and partially reduced to fines when going through the suction system. Grounding of the truck is required. This method is the fastest and the easiest one.



CECA


Unloading 3/3

CECA Adsorbents Handling Procedures DISPOSAL OF WASTE ADSORBENTS

Before dumping used adsorbents, please consult the corresponding MSDS. If you don’t have it, please ask your CECA representative to send you a copy. Unloaded adsorbents may retain toxic or flammable components. Do not directly flood adsorbents with water, and keep them in bin or big bags until they leave the plant. Depending on local environmental regulations, adsorbents may or may not be disposed in a controlled landfill. Landfill is the final destination of used adsorbents in most cases. Preliminary analysis of adsorbents are requested to determine the type of appropriate landfill. If the adsorbents cannot be spread on an open field, it is then necessary to dead burn them in cement factory ovens, and to further use them as raw material for the cement industries. This is especially true for very large quantities of used material. Adsorbents residual hydrocarbon content shall be in any case less than 0.5% by weight. Please note that a large number of specialised companies propose to handle used adsorbents. These companies know local regulations and take care of all required testing and administrative declarations. They are usually the same companies handling the other waste chemicals produced in the plant.



CECA


Disposal 1/1

CECA -Adsorbents Handling Procedures

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