Tag Archives: Transformer Oil

CMM-12R

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CMM-12R

The primary focus of  GlobeCore is the development and production of transformer oil regeneration equipment. Among the methods of regeneration the most widely used is adsorption treatment. It is particularly effective for processing the oils containing dissolved products of aging. The adsorbent becomes gradually saturated and requires recovery of its properties. Generally, the reactivation process takes 18-20 hours.

But not all of our customers have the opportunity to allocate the time for sorbent reactivation, because the same time can be spent to process several tens of tons of transformer oil. Therefore, GlobeCore has developed a new CMM-12R plant which on the one hand performs adsorption treatment, and on the other hand, it works round the clock without breaks for the recovery of sorbent.

This year GlobeCore has sold several of these plants. The last commissioning took place on August 25 in Quito (Ecuador). The CMM-12R unit was connected to a transformer without switching the transformer offline. Ecuador is a mountainous country, and the GlobeCore plant had to work in high altitudes, which had no effect on the quality of oil recovery: the results were consistently high. In particular, it was possible to reduce dielectric loss tangent from 11% to 0.7% at 90 ° C, as well as to increase the breakdown voltage up to 80 kV in the first test cycle.

The CMM-12R unit is designed for regeneration of insulating oil and maintenance of power transformers. The capacity of this equipment is 1,000 liters / hour. The equipment allows to:

  • Remove dissolved gas;
  • Remove free and dissolved water;
  • Remove solids;
  • Remove oil decay products;
  • Evacuate a transformer;
  • Heat a transformer and its active part and winding with hot oil;
  • Remove sludge from transformer windings

The CMM-12R unit is a frame structure that includes a degassing section, a regeneration section and an operator room. The degasser performs filtration, heating and vacuum drying of oil, and the regeneration section performs restoration of oil chemical properties. Also, the regeneration section performs multiple reactivations of sorbent. The operator room has a control cabinet, a desk etc.

To get started, the equipment is filled and connected to the transformer via the TSS security system. The next step is to warm up the unit and bleed the air.

During regeneration, the oil is pumped through the lower port of the transformer and fed into the degassing section. The degasser filters and heats the oil. The heated oil flows into the regeneration section. After regeneration, the oil reenters the degasser. The degassed oil goes through final fine filtration. Then it is pumped back to the transformer.

The CMM-12R unit has the following advantages:

  • Round the clock regeneration of transformer oil without breaks for sorbent replacement;
  • Online and offline transformer maintenance;
  • Manual and automatic control;
  • Control via GSM-module (mobile phone);
  • Condition monitoring of all major components
  • Operator  room equipped with air conditioning and a computer;
  • Operated by 1-2 operators.

If you value your time, the CMM-12R unit is for you. With this equipment you can easily regenerate transformer oil 24 hours a day!

Transformer Oil Bleaching

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Fuller Earth

The exploitation of transformer oil leads to the loss of its original color. Oil discoloration is one of the indicators of profound physicochemical changes. There are various factors causing oil darkening, but they are mostly associated with its contamination by various impurities and oxidation products.

Adsorption refining is the most effective technology in the performance of a transformer oil bleaching task.  It is based on the absorption of harmful impurities using special substances called adsorbents.

Synthetic Zeolite is most commonly used for the elimination of water.  The effectiveness of zeolites is determined by their structure, particularly, by the presence of charged oxygen ions on the surface of the pores.  They provide a high adsorbent capacity, especially in relation to the polar water molecules.

The type of the adsorbed substance depends on the size of pores’ inlet holes in which molecules can permeate.  That is why zeolites are sometimes called “molecular sieves.”  The adsorption of the transformer oil’s molecules does not occur because, as a rule, the size of the oil molecules is much larger than the size of contaminant molecules.  Therefore, they are unable to pass through the zeolite pores.

Pure zeolites have the form of a fine crystal powder.  But, this form is inapplicable for practical purposes therefore, zeolite granules are used.  Their mechanical strength fully comlies with all necessary requirements.  Adsorption refining of transformer oil by means of zeolites removes the dissolved moisture found in the oil.

Natural adsorbents may also be used to remove impurities from the oil. First of all we are talking about bleaching earth.  Fuller’s earth is highly efficient in the context of transformer oils processing.

Fuller’s earth is a soft clay product found in the montmorillonite group of minerals that form microscopic chrystals.  The main feature of this adsorbent is the lattice pattern it forms that allows for the adsorbing of various ions (mostly cations) as well as providing an ion exchange.

Fuller’s earth is most frequently used for the processing of petroleum products.  Transformer oils are no exception – they are also bleached with Fuller’s earth.

GlobeCore has developed and supplies bleaching equipment for transformer oil processing.  Today GlobeCore manufactures several different equipment models using the principle of adsorption with the application of various adsorbents.  This provides many choices in finding the optimal equipment for each specific customer’s needs.

Special attention should be paid to GlobeCore’s СММ-R-type plants designed to purify, regenerate and bleach transformer oils.  They consist of separate blocks for filtering, degassing, regeneration and adsorbent reactivation. Fuller’s earth is used as the adsorbent in the the CMM-R line of equipment.  The adsorbent has a capacity of 300 reactivations which is equivalent to between 1.5 to 3 years of operation.

It is possible to connect СММ-R plants and to process oil directly in an operating transformer.  It reduces operating costs and eliminates possible electrical supply interuptions.

Transformer oils recycled by GlobeCore СММ-R units are fully restored to their original performance characteristics and can be reused for the service life of the transformer.

The equipment for transformer oil purification, that is manufactured and supplied by GlobeCore, is mobile, eco-friendly and energy efficient.

Transformer Oil Processing Plants

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Oil derivatives account for a significant share of toxic waste produced by modern industrial facilities. These materials are a cause of water, soil and air pollution.

Among the main producers of waste oil products are the electrical industry, chemical industry, metallurgical industry, and oil processing industry facilities.  In the environment, these substances cannot be rendered harmless by natural processes as they are impervious to such processes as biodegradation, oxidation and chemical reactions.  These toxic substances cause irreparable damage to living organisms while polluting the soil, water and air.  Recent studies by the U. S. FDA also suggest that waste oil may cause cancer and birth defects.

Like other forms of waste oil, transformer oil is one of the most hazardous pollutants.  This is mostly due to the polychlorinated biphenyls present in the oil.  These chemicals are resistant to hydrolysis and biodegradation in water, and can form dioxins in the process of photolysis, which are even more toxic.  Even one time contamination of bottom sediment by PCBs causes long term local contamination in water.  Processing of transformer oil therefore, must be one of the mandatory measures for protection of the environment against used oil products.

In practice, used oil can be disposed of, or regenerated.  Both processes can be divided into two subtasks.  The first is the organization of an oil collection infrastructure.  The second is development of regeneration technologies that, are environmentally safe and highly efficient.

This second objective has been successfully achieved by the transformer oil purification systems manufactured by GlobeCore.  GlobeCore equipment not only purifies of used transformer oil, but it also to restores the oil’s performance to its orginal specifications.  Once processed with GlobeCore’s high vacuum degassing and regeneration equipment, used transformer oil can continue to be used in transformers performing as insulator and as a heat transfer medium.

GlobeCore’s CMM-R units provide electric transmission companies with a comprehensive oil processing solution to dielectric oil contamination problems.  GlobeCore oil regeneration systems consist of oil degassing/purificartion and oil regeneration sections.  The units are designed for mobility and can be towed from site to site by truck.

Operation of the units is managed by a microcontroller with a touch screen panel.  CMM-R units operate according to pre-programmed process for eachmode of operation and require almost no operator interaction.

The units are installed inside a metal container that is placed on a semi-trailer or a standard container carrier.  The container is equipped with ventilation, lighting, operator/cpmtrol room and a compartment for tools and accessories.

The process of transformer oil purification involves connection of the regeneration and degassing sections of the CMM-R unit to the transformer.  When a CMM-R unit is connected to the transformer, oil processing can be started.  The oil is heated, filtered and degassed.  The oil then flows into the regeneration section.  Once regenerated, the oil goes back into the vacuum chamber of the degassing unit where gas and moisture are removed.  The final step is micro-filtration before being returned to the transformer.

When the adsorbent of the regeneration section of the CMM-R becomes saturated by contaminants, the plant automatically switches from oil processing mode to sorbent reactivation mode.  During the sorbent reactivation process, oil  continues to be processed in the degassing mode.  After the sorbent has been reactivated, the system automatically switches back to oil regeneration mode.

The GlobeCore regeneration process therefore, not only to purifies contaminated transformer oil, but it also restores the oil back to the original new like performance specifications.  The GlobeCore Process is designed to facilitate significant service life extension of dielectric insulating oils and greatly improve oil-filled equipment reliability.  At the same time, usedoil released into the environment is eliminated and need to buy new oil significantly reduced.

Transformer Oil Degassifier

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In practical terms, transformer oil oxidation is caused not only by contact with atmospheric air but also by gases that become dissolved in the oil. Oxidation is not the only negative after-effect of this process.  Dissolved gases and gases, found in the solid transformer insulation, reduce the dielectric strength of the insultaion system made of both liquid and solid parts.  The oxidation is caused by the fact that occluded gas becomes the source for the development of unwanted electric charges.

The issues of oil degassing and transformer vacuumizing have taken on enormous importance since  transformers with a higher voltage became widely used in the electric transmission industry.  The rate of saturation of oil with gases is determined by the height of the oil column and the contact surface with gas.  The rate of the reversing the process depends on the same parameters.

Vibration may lead to the formation of bubbles in oil, caused by depression zones.  This tends to have an adverse effect on the insulating system’s reliability.  That is why vibration of energized transformers should be reduced to a minimum.  In practice, special units, called “columns” are used to perform vacuumizing.  There is a screen inside a column equipped with atomizers.

To provide the highest level of efficiency, these atomizers should have the largest possible area per unit of volume and the least possible resistance to the oil flow.  The most appropriate atomizers are considered to be a set of devices called “Raschig Rings.”  They are similar in appearance with rings, the diameter of which equals its height. Such rings may be made of different materials such as metal, porcelain, and ceramics.

In practical terms, electric utilities use GlobeCore CMM-R units for transformer oil degassing.  They are designed to remove gases, mechanical impurities and to heat up transformer oil found in transformers with a voltage of up to 1150 kW.  In addition, such equipment may also be used to heat up oil-filled electrical equipment and to dry and vacuum transformers.

The following are the parameters of processed oil:

  • gas content, %, no more than 0.1;
  • mass moisture content, g/t, no more than 5;
  • ISO 4406 purity class – 9.

What’s the Catch in Oil Regeneration/Reclamation?

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Nowadays, more and more industrial facilities try to make their activity consistent with sound environmantal rules.  Many companies are trying to do their part in environmental preservation.  In particular, they try to join different environmental agencies and seek cost-effective solutions to manage waste, including regeneration or recycling of used oils.  All these efforts are targeted at environmetal risk elimination.    Different state and local authorities have developed a set of regulations for used oil management.  One such establishment is the U. S. Federal Government’s Environmental Protection Agency (EPA) that has set up rules and regulations for industry to manage used oil.  These so-called “green” regulations however, do not require industrial facilities to change used oil, but merely suggest possible ways of its management such as recycling or reclaimation.

In general, both recycling and reclamation processes are targeted at recovery and re-use of material that has already served its purpose so it can continue to be used.  But recycling and regeneration/reclaimation are slightly different. Usually, the performance chracteristics of reclaimed oil are restored to its original condition so it may be used again in the field for whcih it was originally formulated.  The service life oil that is removed for  recycling comes to an end and it is re-refined to new lube oil or may be used as industrial fuel in other industries with less stringent requirements.  Sometimes, the term oil recycling is used to mean burning oil or disposing in landfills which is completely unacceptable in the twent first century.

According to EPA standards, used oil is considered to be off-specification if it doesn’t satisfy the following permissible levels:

  • Arsenic – 5ppm max
  • Cadmium – 2ppm max
  • Chromium 10 ppm max
  • Lead 100 ppm max
  • Flash point – 100 F min
  • Halogens – 4000 ppm max

It is possible that this oil may be used as fuel for coke ovens or lime kilns in industries subject to EPA guidelines.  Every industrial facility should have a well-developed plan of how to manage their used lubricants.  When oil can no longer perform its functions, it should be processed in the most appropriate way. In order to define whether to recycle or reclaim oil, testing of an oil sample is recommended.

Industrial oil types such as transformer oil, turbine oil, hydraulic fluids, and industrial oils may be reclaimed without degrading their lubricating properties.  As a rule, reclamation includes such procedures as (1) filtration (removes slugde and foreign particles); (2) centrifuge treatment (removes impurities and moisture); and (3) vacuum dehydration (removes water). If transformer oil has to be reclaimed, often it is filtered using a sorbent material such as Fuller’s Earth.

Fuller’s Earth is a special bleaching clay that adsorbs all impurities. But when used to clean and filter oil, many companies have to cope with the problem of disposing of the contaminated sorbent when it is saturated and can no longer remove contaminants from the oil.  GlobeCore therefore, developed a special and unique process to reuse the Fuller’s Earth sorbent materials.  Designated as the CMM-R line, this advanced equipment allows equipment owners to kill two birds with one stone: to reclaim oil without generating hazardous waste by reactivating the exhausted Fuller’s earth up to 300 cycles before disposal as non-hazardous waste. Additionally, CMM-R units can perform high vacuum degassing, filtration, and remove acidic materials on an energized transformer.

Special attention should be paid to the reclamation of turbine oil since after filtering, turbine oil has to continue to perform very important functions such as lubrication, sealing, cooling and preventing corroision.

There has been an increased demand for hydraulic oil reclamation.  Equipment owners therefore try to seek cost-effective solutions to restore their oil to its original condition.  The peculiar feauture of hydraulic oil is that it is able to accumulate sediment during high-pressure operations. Therefore, processes such as adsorption, vacuum dehydration and filtration are desirable techniques in reclaiming hydraulic oils and fluids. As a result of these processes, particulate matter, moisture, and other contaminants are removed.

GlobeCore has developed a cost effective solution for high-quality  oil purification. GlobeCore equipment is designed to degass and purify different types of oil, including hydraulic fluids and turbine oils. The GlobeCore UVR line allows for removal of particulate matter, gasses and other contaminants. Fluids, processed on UVR units comply with international standards for high purity requirements.

GlobeCore equipment has been operated in more than 70 countries of the world and has enjoyed a wide popularity. So, it’s time to get with the Process, the GlobeCore Process!

Regeneration of Transformer Oil and Insulating Systems

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It has been known by the electric transmission industry that electric power transformers are aging rapidly and will have to be replaced or repaired when the  expected service life comes to an end. The price of replacing transformers however, has increased tremedously and placed a great financial burden on transmision companies and other owners of oil filled transformers.

Electric generating and transmission companies therefore, have been forced to seek less expensive alternatives to extend the service life of their current equipment.  The service life of the transformers is mainly determined by the condition of the magnetic conductor and the cellulose insulating paper otherwise known as the “Soild Insulation.”  Any damage done to the solid insultaion will have a negative impact on the service life of the oil filled transformer.

In theoretical terms, the service life of the magnetic conductor is unrestricted, but the cellulose insulation can get old and deteriorate very quickly.  The service life of the transformer therefore, largely depends on the condition of the cellulose insulation.

A wide range of factors, that speed up the aging process of the cellulose insulation are as follows:

(1) excessive heating;

(2) high moisture and oxygen content in the insulating oil; and

(3) bi-products of the oil aging process.

It is worth noting that it is the cellulose insultatoin that attracts contaminants by performing the function of a filter.  The solid insuation retains the products of the oil aging process and those products work to degrade the solid insulation over time.  More impurities are normally found in the solid insulation than in the liquid insulation.

It is therefore, the purification and cleaning of the cellulose insulation that is one of the most significant processes required to extend the service life of the transformer.  This process can be divided into two sub-processes such as:

(1) oil reclamation; and

(2) the washing, cleansing and purificationof the cellulose insulation.

The following is a discussion of the existing ways and methods used in cleaning and removing contaminants from the cellulose insulation.

A complete change of transformer oil is not a solution to the problem because not all the contaminated oil is removed from the windings and the solid insulation.  Some amount of the products of the aging process are retained in the solid insulation and eventually leach into the new oil effectively reducing the service life of the new oil.

This process represents a circle of continuing contamination and celulose degradation: the aging products oxidize the fresh product, which gets old and again saturates the cellulose with decay products.   The process of oil reclamation is almost the same as changing the oil, though it is much more thorough and much more cost effective.

The insulation may be washed over while performing a complete overhaul.  The aging products are removed due to spraying of pure process oil.  The disadvantage of this method is that the aging products are not removed in the depth of the insulation.  The effectiveness of the washing is improved by using special detergent oils.  But, they are very expensive and the process lasts longer than the usual one.

The overhaul and the cellulose purification make up asmuch as 30% or more of the new transformer value.

GlobeCore branded equipment, designated as CMM-R line, is the most cost effective solution to use in order to extend the service life of transformers.  GlobeCore produces highly-effective systems for the purification, degassing and regeneration of dielectric insulating oil.

The distinctive feature of the GlobeCore CMM-R unit is that it allows the operators to work with insulating liquids while transformer is energized.  GlobeCore equipment therefore, solves a wide spectrum of problems related to cellulose insulation purification.

The general operating principles of the CMM-R unit are as follows:

(1) it is connected to the operating transformer;

(2) the oil is circulated through the equipment;

(3) contaminated product is removed from the transformer, then passes through regeneration and degassing blocks; and

(4) purified and regenerated oil is then returned to the transformer.

A high circulation speed allows for the removal of aging and contamination products from the solid insulation.  The purified oil again returns to the CMM-R unit, where it is degassed and regenerated once again.

Other important advantages of the equipment, designated as CMM-R, are as follows:

(1) minimal oil loss during the regenaeration process;

(2) oil reclamation and solid insulation purification are performed simultaneously;

(3) the regeneration of Fuller’s earth (adsorbent) inside the equipment is eco-friendly;

(4) uninterrupted operation of the transformer; and

(5) the service life of the cellulose insulation is extended due to the complete removal of aging products and contaminants.

The results of the laboratory analysis of oil processed with the CMM-R equipment are given below.

Oil Specifications

Specification Before processing

After processing

IEC (International Electrotechnical Comission) standard 60296
Physical form dull, dark brown pure, transparent pure
Acid number, KOH mg/1 g oil 0.63 0.01 0.01
Dielectric dissipation factor at 90 ºС, % 4.0 0.001 0.005
Moisure content, ppm 170 5 30-40
Breakdown voltage, kV 11 73 30-70

The analysis shows that the performance characteristics of oil, processed by GlobeCore branded equipment, comply with IEC standard 60296.

How to Recycle Fuller’s Earth?

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Historical facts

Adsorption purification was first applied in order to remove asphalt and resinous unwanted substances from oil fractions in the early years of the modern oil industry.  At the very beginning, bone coal was used to lighten kerosene and heavy-oil products.  But, as time went on, Bone Coal was replaced by Fuller’s Earth and the Fuller’s Earth turned out to be more effective during the purification of cylinder distillates performed in 1893.

Nowadays, adsorption purification is often applied to remove the resinous colored substances from lubricating oil.  During the percolation process by the Fuller’s Earth, oil fractions are divided into parts that differ in color, specific weight and other properties.  It was David T. Day who first described this phenomenon in an article that drew oil recycling process researchers’ attention to the properties of Fuller’s Earth.  For example, another reasearcher named Kaufmann, discovered that the first portion of cylinder oil, filtered by the Fuller’s Earth, had lower density and viscosity and less coke value than the following fractions.

The properties of each new portion more and more resembled the properties of the source raw material.  It has been established that the properties of the substance were changed because sulfuric, nitrogenous, oxygen-containing compounds, as well as polycyclic and aromatic hydrocarbons, were being absorbed selectively. Nowadays, such processes as contact purification and percolation are based on this time tested principle.

GlobeCore Fuller Earth for transformer oil

The Fuller’s Earth sorbent materials

In the course of contact purification, oil makes contact with the adsorbent for some time at a pre-set temperature. At the next stage, unwanted adsorbent components separate from the oil product.

During the percolation phase, oil runs through the column of Fuller’s Earth under pressure that provides the necessary flow rate.  The adsorbent grains are used to carry out this process.  The fine-grained earth can be applied only during contact purification.

Fuller’s Earth Reactivation: Is it Possible?

There are about 35 to 40% of resinous and oil substances left in the Fuller’s earth after an oil treatment cycle.  It makes no economic sense to dispose of the contaminated product or buy new sorbent after each oil purification process.  Firstly, it will cost much money and efforts to buy new Fuller’s Earth all the time.  Secondly, the disposal of contaminated sorbent is time-consuming and requires significant expenditures.

With this in mind, the engineering department at GlobeCore has developed a unique technology that completely reactivates the Fuller’s Earth sorbent materials without removing the material from the oil regeneration columns!

This advanced GlobeCore technology allows the sorbent to last and be used over and over again for between 2 and 3 years (up to 300 cycles) with no impact on the oil reclamation process.  This is the revolutionary feature that distinguishes GlobeCore’s machines from the machines of other manufacturers.  The Fuller’s Earth however, cannot be used indefinetly.  When it is finally exhausted after years of service, the Fuller’s Earth can be disposed of as “Non-Hazardous” waste.

The following reflect some of the laws and regulations that determine the management and disposal of exhausted in the European Union countries.

Exhausted Sorbent Management in Europe

Waste Management has been considered to be one of the key priorities of the European Union (EU) since it was founded.   In countries such as Germany, Austria, Denmark, Finland and Italy, waste management has been tightly regulated by the state since the early 1990s.

Generally speaking, two special documents such as (1) waste regulations and (2) hazardous waste regulations, determine the way waste is managed in the countries of the European Union (EU).

There are some regulations that have been adopted to govern the management of special waste.  It is therefore, the members of the EU that have to improve or draft legislation so that the member nation can fully comply with the purposes and requirements of the EU regulations.

All the different wastes are divided into two classes: (1) hazardous; and (2) non-hazardous.  The way the exhausted Fuller’s earth is managed is determined by the class of the wastes it belongs to.  It is clear that the rate of the sorbent’s hazard is determined by the amount and composition of oil that it contains.  For example, in Germany, oil is determined as hazardous waste if it contains more than 20 mg/kg of PCB’s (polychlorinated biphenyls).  These substances are collected and delivered to special collection centers which have them recycled by special hazardous waste handling companies.

Generally, people deliver hazardous waste to the collection centers themselves, but if it is an industrial facility,  hazardous waste is taken by special machines and containers directly from the site.

In some countries of Western Europe, recycling is considered to be the main method of hazardous waste management.  In other countries however, they are buried and/or burned.

To comply with the requirements of waste dumping rgulations, many countries require that the waste be stabilized by reducing the amount of hazardous substances in the waste in order to meet acceptable levels.  Waste stabilization may be performed by physical and/or chemical treatment.

In South Australia, the used, oil-containing, sorbent is managed according to the ‘Environmental Protection Act’ of 1993.  Article 25 of the Act determines common ‘environmental (also called ‘green’) taxes,’ that should be imposed on individuals whose activity results in environment pollution.   Additionally, it requires all reasonable measures to be taken to prevent and reduce the amount of hazardous waste generation.

If the used sorbent contains a small amount of oil  (up to 0.1m3), it may be disposed of as solid waste at a waste collection center.  The latter should have a license to carry out such processes.

Therefore, before the sorbent is disposed of, it should be (1) tested to determine the toxicity; and (2) extracted.

The results will show if it is possible to mix the exhausted sorbent with other industrial wastes when collecting, transporting or recycling them at collection centers.

If there is more than 100 kg of the sorbent, and it is contaminated with fluid that contains light and medium hydrocarbons, this waste should be delivered to special facilities to be treated or disposed of in accordance with current laws and regulations.

In case of any doubts, please, consult the specialists on the environmental hot line.

In the USA, used sorbent disposal procedure differ among the states.

In 2012, the California Department of Natural Resources issued a special document, called “Used oil filters and adsorbents. Questions and Answers.”  It reflects the basic principles of oil-containing materials management such as exhausted Fuller’s Earth.   According to this document, the disposal of absorbent that contains waste oil is forbidden in landfills.

The following are exempt from those prohibitions:

  • Exhausted sorbents with no visible signs of oil content;
  • Non-hazardous sorbents;and
  • Sorbents that were cleaned to remove oil.

Apart from landfills, there exist other possible ways to manage exhausted sorbents.  In particular, some companies that are engaged in adsorbent production also collect exhausted material in order to purify it.

Used oil that has been previously removed from adsorbent can be burnned for energy recovery.  The sorbent grains can be recycled or also burnned for energy recovery at officially recognized facilities.

Landfill operators should take the following measures to prevent the delivery of absorbent that contains used oil:

(1)  Place warning signs against oil contaminated waste;

(2)  instruct staff to look for and reject oil contaminated waste; and

(3)  inform their customers about the prohibitions.

A similar situation has also been observed in other states.  In the USA, exhausted Fuller’s Earth is managed in the following way.

First, the oil is drained and then disposed of.  After all hazardous substances have been removed from the Fuller’s Earth, it can be managed as solid waste.  If Fuller’s earth has not been cleaned and hazardous substances removed, it should be delivered to the officially-recognized facilities to have it purified.

In Russia, exhausted Fuller’s Earth management is regulated by the Act of the Ministry of Natural Resources “Adopted Criteria for Classification of Environmentally Hazardous Waste” and by the Federal law No. 89, “Production Wastes and Consumption.”

First, waste containing oil should be tested in a special laboratory to determine the class of hazard.  In Russia, all waste is divided into 5 classes such as:

I – extremely hazardous waste;

II – highly hazardous waste;

III – moderately hazardous waste;

IV – low-hazard waste; and

V – non-hazardous waste.

After that, waste is documented and delivered to special centers that are involved in landfills or in the disposing of hazardous waste.

It should be mentioned that in Russia, there is a Federal Waste Classification Catalogue, where the “bleaching of clay containing oil,” is considered to be the 4th class of hazardous waste.  But, since Fuller’s earth may be disposed of under different operating conditions, it is necessary to test it each time.

In Ukraine, used adsorbents are burnned or placed into a landfill.  Only bulk and free from clogs adsorbents may be burnned. It is therefore, adsorbents, based on polymer, synthetic, carbon fibers or polypropylene and foam plastic that are exempt from burning.

You might have noticed that legislation provides only general recommendations for the waste management. So, what is the most practical way to dispose of used Fuller’s Earth?

Bleaching clay is considered to be a valuable raw material for cement and brick manufacture.  Tons of waterproof cement, based on used bleaching clay is in commercial production nowadays. According to the cement production formulas, about 3% of used bleaching clay is added to the mill while grinding clinker.  Different resinous substances, present in the used bleaching clay, makes cement plastic, waterproof, and hard.

The experiments have shown that when adding 15 % of used bleaching clay to the source raw material, the final product will have good performance characteristics.  Used bleaching clay should be cleaned and hydrocarbons should be removed before applying it into the cement production mixture.

Clay that has been cleaned of oil may be applied as a filling material in the road construction industry or as a component of insect powder in agriculture.

Additionally, de-oiled bleaching clay may serve as a good raw material when manufacturing fire-clay bricks.  Such technology provides for the reduction in the fuel consumption when burning bricks.