CECA -Adsorbents Handling Procedures

8/9/2019 CECA -Adsorbents Handling Procedures

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PROCEDURE

CECA ADSORBENTS FOR THE OIL AND GAS INDUSTRY

HANDLING

PROCEDURES


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CECA Adsorbents Handling Procedures

CONTENT :

INTRODUCTION

BASICS OF ADSORPTION

STORAGE INSTRUCTIONS

HANDLING INSTRUCTIONS

VESSEL LOADING INSTRUCTIONS

VESSEL UNLOADING INSTRUCTIONS

DISPOSAL OF CECA ADSORBENTS


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INTRODUCTION

This document details CECA requirements for the

handling of adsorbents (molecular sieves, activated

alumina, silica gel) and ceramic balls in process units.

All the information and recommendations enclosedshould 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 bedisclosed to any third party without CECA explicit

consent in writing.

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 03Email : [email protected]

BASICS OF ADSORPTION

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 releasesenergy in the form of heat).

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 ofadsorbent, 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.

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 itsoriginal adsorption capacity: it is “regenerated”.

Introduction


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STORAGE 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.

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.

Outside storage is not recommended, in particular forbig 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.

HANDLING INSTRUCTIONS

Before handling CECA adsorbents, read the

corresponding Material Safety Data Sheet (MSDS)

for the up-to-date safety, handling and regulatory

information.

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.

The main potential serious hazard is related to non

(or poorly) regenerated adsorbents desorbing

hazardous species (H2S, 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 witheyes. The use of dust mask, goggles, and Breathing

Apparatus systems, if in confined space, are

mandatory. Excessive or severe handling can cause

some dusting.

Do not hesitate to contact us for any question you

may have :



Tel : +33 1 49 00 38 19


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.comStorage & Handling 1/1


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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

for 1 pallet (4 drums or 1 big bag) is about 1m2.

Moreover, some space is necessary for the loadingprocess : 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 5drums = 500 to 700 kg) or 1 big bag (800 to 1000 kg).

The bottom opening must be large enough to preventclogging. 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 isusually 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


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Attached to the bottom of the hopper, or to a cone-

shaped 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 equalto the diameter of the bottom opening 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

is reduced from time to time, in order to always havebetween 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.

Example of an equipped hopper

1.3/ Crane

A crane is required to lift the filled hopper (or the big

bags) from the ground up to the vessel manway.

1.4/ Forklifts

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, andanother 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 securedplatform 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 casedrums are simply rocked on the hopper.

sleeve

rope

valve

Cone-bottomshaped hopper

pouredproducts

Figure 1

sleeve

rope

valve

Cone-bottomshaped hopper

pouredproducts

Figure 1

liftedbig bag

sleeve

rope

Figure 2

liftedbig bag

sleeve

rope

Figure 2

Loading 2/7


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1.6/ Safety equipments

Safety / PPE (Personal Protective Equipment) outfits

and fittings have to be available and used accordingto the plant’s safety rules. Contact CECA in caseyou have any question or any doubt. Equipment

typically includes :

Helmet, gloves, safety shoes, dust mask, harness,

goggles, clothes with long sleeves, Breathing

Apparatus systems, portable oxygen detector.

1.7/ Wood boards and ladder

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 ladderand walk on the bed during the levelling steps.

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.

1.9/ Rulers

Rulers are useful to measure the level of product in

the vessel from time to time, and therefore controlits 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 aresupplied in several pieces that have to be partially

overlapped and tied together (usually for large vesseldiameters).

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.

1.12/ Tarpaulin - Plastic cover

If sudden rain or snow occurs during the loading

operation, it is important to be equipped to protect theproduct from exposure (hopper and vessels). For eachvessel, at least one plastic cover, to be put on the

manhole, is requested. Tape is needed to fix it tightly.

1.13/ Lighting equipment

Lights (flashlights, spotlights) are needed to see insideand inspect the vessels.

1.14/ Other useful tools

Cutters, scissors, adhesive tape, etc.

2/ UTILITIES

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.

3/ MANPOWER

In order to proceed securely, we highly recommend tohave at least 7 workers per team. We also suggest the

following dispatch :

Crane : 1

Forklifts : 2

Hopper filling / big bag preparation : 2

Filling operation / levelling / supervision : 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 andcommercial agreement, involve a CECA

representative. In that case, the CECA representativeis 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


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4/ PRELIMINARY OPERATIONS & SPECIAL

RECOMMENDATIONS

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, theyare 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.

4.3/ Grid – wall sealing

Due to thermal expansion (especially in the case of a

TSA - Temperature Swing Adsorption system), thesupport grid and the vessel show a little gap. In orderto 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.

Ceramic rope sealing

Figure 3

Loading 4/7

Ceramic balls layers


Ceramic balls 1”

Alumina or Silica gel guard bed layer

(when applicable)

Molecular sieves layers

Fiber rope around the

whole circumference

(gasket / tightness)

Manhole /

dump port

Baffleplate

with 4

holes

Inlet nozzle with rectangular slots

showing suitable open area, and

covered with 20 mesh screen*.

Bottom of distributor

Top of products

600 mm

mini.

20 mesh screen*

(+ 15 cm overlap)

10 mesh screen*

3 mesh screen*

Main support grid

I-beam supports 20 mesh screen*

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

Floating screen

Optional and strongly recommended : Hold-down ring

all around the vessel circumference, to reliably maintain

the bottom screens and ensure a suitable tightness



Ceramic balls 1”

Alumina or Silica gel guard bed layer

(when applicable)

Molecular sieves layers

Fiber rope around the

whole circumference

(gasket / tightness)

Manhole /

dump port

Manhole /

dump port

Baffleplate

with 4

holes

Inlet nozzle with rectangular slots

showing suitable open area, and

covered with 20 mesh screen*.

Bottom of distributor

Top of products

600 mm

mini.

20 mesh screen*

(+ 15 cm overlap)

10 mesh screen*

3 mesh screen*

Main support grid

I-beam supports

20 mesh screen*

(+ 15 cm overlap)

10 mesh screen*

3 mesh screen*

Main support grid

I-beam supports 20 mesh screen*20 mesh screen*

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

Floating screen

Optional and strongly recommended : Hold-down ring

all around the vessel circumference, to reliably maintain

the bottom screens and ensure a suitable tightness


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In addition to that, the upper 20 mesh screen overthe 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.

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.

Figure 4

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 mainstorage to the loading operation area. Removal /

disposal of empty packaging has to be planned aswell, 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 theorder 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.

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.

During the night, manholes have to be hermeticallyclosed. If possible, it is recommended to flow dry air

or nitrogen into the vessels.

5/ LOADING OPERATION

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 questionarises.

Loading 5/7

Ceramic balls

Grid and screens

Ceramic balls

Grid and screens


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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.

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 openingthe 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 andcontinuously 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 arepreferably loaded using a rope and buckets (or

directly through the side manhole when there is one).

It is necessary to first put the ceramic balls all aroundthe 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.

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 alsoperformed 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, seeFigure 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 samediameter 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


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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 turbulentflow. 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 the 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 moisturewould come in.

Do not hesitate to contact us for any question

you may have :



Tel : +33 1 49 00 38 19









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



cecachemicals.com Loading 7/7


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VESSEL UNLOADING INSTRUCTIONS

1/ SAFETY

Unloading adsorbents from a process vessel requires

a good knowledge of the application and a thoroughunderstanding 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 accordingto 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, BreathingApparatus 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 non-

conducting 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 products, 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 fire-

fighters.

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


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1.2/ Last Regeneration

Before being unloaded, the adsorbents must be

properly and completely regenerated in order to

remove as much adsorbed compounds and depositsas possible. Use the same regeneration procedure asusual, 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 betweenthe 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 alsocompletely 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 H2S 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 generallyfaster 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 toatmospheric 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 theflare. The nitrogen flow-rate must be sufficient to

avoid channelling. Minimum flow-rate and durationof 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 usuallydone at a tap on the flare line, using an appropriateanalyser.

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 flareline 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 3to 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 theadsorbents and the ceramic ball layers are totally

flooded by water, but be careful not to overfill andflood 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 bottom tap connectedto water and a top tap connected to a vent line and to

Unloading 2/3


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the flare. A water flooding process can therefore beimplemented 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.

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 sidemanway. 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.

Used material can be removed either by pneumatic

unloading (vacuum unloading), or by gravity

unloading.

Pneumatic unloading :

If a pneumatic truck is chosen, the adsorbents must

be dry. A flexible pipe is put into the vessels andsucks 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.

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 ofmetal or wood is put below the manway to direct theflow 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.

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.

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.

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


you may have :



Tel : +33 1 49 00 38 19

Fax : +33 1 49 00 38 03

Email : [email protected]











CECA



cecachemicals.comUnloading 3/3


15/15


DISPOSAL OF WASTE ADSORBENTS

Before dumping used adsorbents, please consult thecorresponding 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 ofappropriate 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 ofall required testing and administrative declarations.

They are usually the same companies handling the

other waste chemicals produced in the plant.


you may have :


Dynamic ApplicationsTel : +33 1 49 00 38 19

Fax : +33 1 49 00 38 03

Email : [email protected]











CECA


Date post:	01-Jun-2018
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CECA -Adsorbents Handling Procedures

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