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CR Asia (Singapore) Pte. Ltd. (CRAS) has performed two quite remarkable chemical cleaning jobs using WVT Chemicals.

{ 20 mei, 2014 }

 

CR Asia China have completed a catalyst skimming and spent catalyst conditioning job of two Bisphenol reactors at a facility in SCIP, Shanghai.Bisphenol-A is the used for the production of Poly Carbonate, from which, for example, CD-s are manufactured.

The job was for two reactors, the first one was handled in March and the second one in August 2011.

The scope of work included the skimming of the reactor by vacuuming from the top. The phenol-rich catalyst was loaded into a specially designed cyclone. The cyclone was fitted with chemical cleaning connections and screens so that the catalyst could be washed by circulation. The screens prevent the catalyst from entering the chemical-flow. The chemical cleaning circuits were equipped with reverse-flow manifolds in order to free the screens of accumulated catalyst by back-flushing in case of clogging.

After sufficient washing the wet catalyst was dumped in a catalyst collection bin. The catalyst collection bin is equipped with a double floor again containing screen. This allows for the chemical solution to be pumped-back into chemical circulation tanks.

When the collection bin is full, the dry catalyst is loaded in one of the CRAC vacuum trucks and transported to an incineration facility for final disposal.

The chemical circulation tanks as well as the catalyst collection bin are equipped with ridged and tarpaulin covers. An air-propelled ejector system is pushing all fumes to a gas-washer and activated carbon filter.

The spent chemicals were collected in ISO tankers for proper disposal.

The chemical mixture used to release the phenol from the catalyst was an aqueous caustic solution with WVT’s O-Scent SCV. The O-Scent SCV was initially meant for reducing the dissolved phenol in the washing water. The O-Scent SCV proved very beneficial as a surfactant coping with an unexpected tarry substance that appeared during the catalyst washing. Furthermore O-Scent SCV was effectively used in the wet-scrubber gas washing system where it eliminated even traces of phenol vapour in the surrounding air. No phenol vapour could be detected by the client’s sensitive gas detection systems.

As this was the first time this concept was used, the initial operation was full of challenges. Phenol concentrations and catalyst grain-size were not as initially expected. This called for some major design changes and improvements. The activity on the second reactor finished well ahead of schedule and without any material failure, accident, incident or even a first-aid case.

Philippines:

CR Asia Singapore has recently performed chemical cleaning of a “Packinox” Combined Feed/Effluent Heat Exchanger at a refinery north of the Manila Bay in the Philippines. This particular Packinox is part of the Continuous Catalytic Reformer (CCR) Unit and first one ever cleaned under the banner of CR-Asia. Every CCR has a feed/effluent heat exchanger but there are mainly two configurations; the Packinox and the Texas tower. The Texas tower is a tubular heat exchanger and the Packinox is a welded plate-type heat exchanger.

 

 

Texas Tower Heat Exchanger :

 Texas Tower

Texas Tower2

The client informed CRAS that chemical cleaning was to be aimed at the removal of poly-nuclear aromatic hydrocarbons – PAH. In close cooperation with our long-time chemical supply partner WVT Industries NV from Belgium the perfect product for this type of cleaning was chosen. The product, C-Clean Bio, is based on D-limonene. The raw material is retrieved from orange-peel. It is a natural-occurring turpentine. Next time you peel an orange, take the skin and squeeze it. The liquid originating from the skin is D-limonene but take care, it is flammable.

The C-Clean Bio solution did a very good job with the removal of hydrocarbons but much to everyone’s surprise a large amount of magnetite was also released in the form of magnetic black fines.

The choice and approval for C-Clean Bio was based on its excellent hydro-carbon dissolving capabilities and safe usage; safe for circulation and handling but also safe to be used on all metals. As it emulsifies with water there is no explosion danger and no possibility for the build-up of static electricity.

The often used alternative is washing by fill-and-soak-method using toluene.

The C-Clean Bio emulsion also proved to be no problem for the refinery’s wastewater treatment system so the product and rinsing water was drained in the oil water separator.

After the C-Clean Bio treatment the stainless steel of the cooler plates were passivated using ammonium citrate and a suitable oxidizer to assure an uninterrupted chromium oxide layer. Chromium oxide is essential for the corrosion resistance of stainless steel.

Name:

CR Asia (Singapore) Pte. Ltd. (CRAS) has performed two quite remarkable chemical cleaning jobs using WVT Chemicals.
Description:

 

CR Asia China have completed a catalyst skimming and spent catalyst conditioning job of two Bisphenol reactors at a facility in SCIP, Shanghai.Bisphenol-A is the used for the production of Poly Carbonate, from which, for example, CD-s are manufactured.

The job was for two reactors, the first one was handled in March and the second one in August 2011.
The scope of work included the skimming of the reactor by vacuuming from the top. The phenol-rich catalyst was loaded into a specially designed cyclone. The cyclone was fitted with chemical cleaning connections and screens so that the catalyst could be washed by circulation. The screens prevent the catalyst from entering the chemical-flow. The chemical cleaning circuits were equipped with reverse-flow manifolds in order to free the screens of accumulated catalyst by back-flushing in case of clogging.
After sufficient washing the wet catalyst was dumped in a catalyst collection bin. The catalyst collection bin is equipped with a double floor again containing screen. This allows for the chemical solution to be pumped-back into chemical circulation tanks.
When the collection bin is full, the dry catalyst is loaded in one of the CRAC vacuum trucks and transported to an incineration facility for final disposal.
The chemical circulation tanks as well as the catalyst collection bin are equipped with ridged and tarpaulin covers. An air-propelled ejector system is pushing all fumes to a gas-washer and activated carbon filter.
The spent chemicals were collected in ISO tankers for proper disposal.
The chemical mixture used to release the phenol from the catalyst was an aqueous caustic solution with WVT’s O-Scent SCV. The O-Scent SCV was initially meant for reducing the dissolved phenol in the washing water. The O-Scent SCV proved very beneficial as a surfactant coping with an unexpected tarry substance that appeared during the catalyst washing. Furthermore O-Scent SCV was effectively used in the wet-scrubber gas washing system where it eliminated even traces of phenol vapour in the surrounding air. No phenol vapour could be detected by the client’s sensitive gas detection systems.
As this was the first time this concept was used, the initial operation was full of challenges. Phenol concentrations and catalyst grain-size were not as initially expected. This called for some major design changes and improvements. The activity on the second reactor finished well ahead of schedule and without any material failure, accident, incident or even a first-aid case.
Philippines:
CR Asia Singapore has recently performed chemical cleaning of a “Packinox” Combined Feed/Effluent Heat Exchanger at a refinery north of the Manila Bay in the Philippines. This particular Packinox is part of the Continuous Catalytic Reformer (CCR) Unit and first one ever cleaned under the banner of CR-Asia. Every CCR has a feed/effluent heat exchanger but there are mainly two configurations; the Packinox and the Texas tower. The Texas tower is a tubular heat exchanger and the Packinox, an Alva Laval product, is a welded plate-type heat exchanger.
The Packinox is a very vulnerable piece of equipment as over pressuring the effluent side can cause substantial damage in a matter of seconds. The vendor therefore is very much concerned and involved in the method of circulation and the type of chemicals used.
The client informed CRAS that chemical cleaning was to be aimed at the removal of poly-nuclear aromatic hydrocarbons – PAH. In close cooperation with our long-time chemical supply partner WVT Industries NV from Belgium the perfect product for this type of cleaning was chosen. The product, C-Clean Bio, is based on D-limonene. The raw material is retrieved from orange-peel. It is a natural-occurring turpentine. Next time you peel an orange, take the skin and squeeze it. The liquid originating from the skin is D-limonene but take care, it is flammable.
The C-Clean Bio solution did a very good job with the removal of hydrocarbons but much to everyone’s surprise a large amount of magnetite was also released in the form of magnetic black fines.
The choice and approval for C-Clean Bio was based on its excellent hydro-carbon dissolving capabilities and safe usage; safe for circulation and handling but also safe to be used on all metals. As it emulsifies with water there is no explosion danger and no possibility for the build-up of static electricity.
The often used alternative is washing by fill-and-soak-method using toluene.
The C-Clean Bio emulsion also proved to be no problem for the refinery’s wastewater treatment system so the product and rinsing water was drained in the oil water separator.
After the C-Clean Bio treatment the stainless steel of the cooler plates were passivated using ammonium citrate and a suitable oxidizer to assure an uninterrupted chromium oxide layer. Chromium oxide is essential for the corrosion resistance of stainless steel.

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