Special Report Chemical Weekly Activated carbon: A Techno-Commercial Profile

Special Report

Activated carbon: A Techno-Commercial Profile

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Introduction ctivated carbon, also called activated charcoal or activated coal, is a general term which covers carbon material mostly derived from charcoal. For all three variations of the name, “activated” is sometimes substituted with “active”. Ordinary commercial charcoal has very limited ability to adsorb substances in the liquid or gas phase. To give charcoal this property it must first be activated by removing the tarry materials, which block the structure of the pure carbon skeleton of the charcoal. When this is done, the surface area of the porous carbon skeleton is increased literally millions of times, providing equally large numbers of sites where molecules of other substances can be adsorbed and thus removed from gases or from liquids in which the treated charcoal is placed. Activated carbon is an amorphous form of elemental carbon prepared by destructive distillation of any one of a variety of carbonaceous raw materials, including wood, coal or coconut shells. It is used as a substrate primarily to selectively adsorb gases, vapours or colloidal solids from liquids or gases. The most significant physical characteristic of activated carbon is the enormous surface area of the internal pore structure developed during its preparation. Total surface areas for activated carbons commonly range from 450-m2/gm (square meters per gram) to 1,800-m2/gm. Three main forms of activated carbon are:

Granular activated carbon (GAC): Irregular shaped particles with sizes ranging from 0.2 to 5 mm; Chemical Weekly April 20, 2010

continuously passed through a column. Bone char, however, consists mainly of calcium phosphate and a small percentage of carbon; this material, therefore, was only used for sugar purification.

Powdered activated carbon (PAC): Carbon with a size predominantly less than 0.21 mm (70 US mesh); and

Pelletised activated carbon: Extruded and cylindrical shaped with diameters from 0.8 to 5 mm. History of activated carbon Adsorption on porous carbons was described as early as 1550 BC in an ancient Egyptian papyrus and later by Hippocrates and Pliny the Elder, mainly for medicinal purposes. In the 18th century, carbons made from blood, wood and animals were used for the purification of liquids. All of these materials, which can be considered as precursors of activated carbons, were only available as powders. The typical technology of application was the socalled batch contact treatment, where a measured quantity of carbon and the liquid to be treated were mixed and, after a certain contact time, separated by filtration or sedimentation. At the beginning of the 19th century the decolourisation power of bone char was detected and used in the sugar industry in England. Bone char was available as a granular material, which allowed the use of percolation technology, where the liquid to be treated was

At the beginning of the 20th century the first processes were developed to produce activated carbons with defined properties on an industrial scale. However, the steam activation (V. Ostreijko, 1900 and 1901) and chemical activation (Bayer, 1915) processes could only produce powder activated carbon. During the First World War, steam activation of coconut char was developed in the United States for use in gas masks. This activated carbon type contains mainly fine adsorption pore structures suited for gas phase applications. Calgon Carbon Corporation (USA) succeeded after World War II, in developing coal based granular activated carbons with a substantial content of transport pore structure and good mechanical hardness. This combination allowed the use of activated carbon in continuous decolourisation processes resulting superior performance. In addition, Calgon Carbon pioneered work on the optimization of granular carbon reactivation. Today, many users are switching from the traditional use of powdered activated carbon as a disposable chemical to continuous adsorption processes using granular activated carbon combined with reactivation. By this change they are following the modern tendency towards recycling and waste minimization, thereby reducing the use of the world’s resources. 183

Special Report Raw materials Charcoal was initially the only raw material for producing activated carbon, but it has been partly replaced due to price considerations and the limited availability of charcoal, by other carbon materials such as coals, lignite, petroleum coke, peat and moss. Pine wood is a well recognized source of charcoal for conversion to activated carbon, and pine based charcoal has been produced in a limited manner in the northern states of Himachal Pradesh and Punjab in India. Bamboo has also been investigated as an alternative. A variety of biomass has also been used for activated carbon production including coconut shells, palm oil shell waste, olive oil mill residues etc. A study has even been done to predict the cost of producing activated carbon from poultry litter by a process developed by the USDA’s Agricultural Research Service Southern Regional Research Center. The study indicated that activated carbon can be produced by this method at a cost of about $1.44 per kg. Experience has shown that there are no basic differences in the quality of activated carbons made from different raw materials, except that, in the gas/ vapour applications, charcoal-based activated carbon is superior. Activated carbon production is a low yield process in relationship to the raw material input, whether or not charcoal is the base. For example, about 90,000 coconuts are needed for the preparation of 1-ton of activated carbon. In India, coconut shell is widely used for manufacturing activated carbon. The shell is carbonized by using 184

techniques such as pit method, drum method, destructive distillation etc. Activated carbon manufactured from coconut shell is considered superior to those obtained from other sources mainly because of its macro-porous structure, which renders it effective for adsorption of gases/vapours and for removal of colours and odours. Activated carbon injection (ACI) represents a promising method to achieve the mercury reductions mandated by the US Clean Air Mercury Rule (CAMR). Although PAC is available for this application, its cost is significant. To address this issue Praxair, an industrial gases producer, is developing a flexible process to produce coal-based PAC at lower cost. Praxair’s process allows for activated carbon production on-site of a power plant by using a portion of the plant’s pulverized coal supply. This process uses a patented oxyfuel burner to devolatilise and activate the coal to produce activated carbon. By simply changing processing conditions, and with simple addition of dopants, this process can produce a wide variety of carbons, allowing the customer to tailor the sorbent’s properties to meet specific mercury capture needs. Manufacturing process The activated carbon industry uses many variations in basic processing methods to achieve activated carbons having optimum properties for the various end-uses. These variations mainly relate to the final stages of processing, rather than the basic activation process, which is usually nowadays carried out by heating the charcoal to a temperature of about 800°C in an atmosphere of superheated steam, which permits the breakdown and removal of the tars blocking the microfine structure of the charcoal.

There are several kinds of equipment used, which depend mainly on the volume of charcoal to be processed. For large throughputs the multiple hearth roasting furnace, as used for producing charcoal from bark and sawdust on a large scale, is often used. Smaller volumes are often processed in a vertical furnace in which the charcoal cascades over refractory baffles, which allow the charcoal to be fully exposed to the atmosphere of the activating furnace. The principle, whatever system is used, is the same: the charcoal is heated and stirred in an atmosphere of superheated steam to burn out the tars. Although in principle other gases can be used steam is most widely used. The hot charcoal leaving the furnace is allowed to cool in steel drums or containers until it reaches room temperature. The charcoal, which is now about the same size as sand grains, is finely ground to reveal the active structure to the maximum extent. At the same time specialised treatment is given to the activated carbon to adapt it for its particular use. For example, activated charcoal intended for purifying vegetable oils is treated differently to charcoal to be used for decolourising wines. All these processes are kept as confidential as possible by the factory, to improve its competitive position in the market. Providing it has a low ash and a low volatile content almost any charcoal is suitable, as long as it is available in dependable quantity and quality. There is one notable exception and that is the charcoal used to make activated carbon for purifying gases as for solvent recovery in printing and related processes and in gas masks for military and civilian use. Chemical Weekly April 20, 2010

Special Report Experience has shown that for gaseous adsorption processes the most suitable charcoal is that from coconut shells since the high strength combined with a fine porous structure of this charcoal allows it to be recycled many times in the equipment without losing its granular structure and impeding the gas flow. Chemical activation Chemical activation is generally used for the production of activated carbon from sawdust, wood or peat. The process involves mixing an organic chemical compound with the carbonaceous raw material, usually wood, and carbonizing the resultant mixture. The raw material is mixed with an activating agent, usually phosphoric acid, to swell the wood and open up the cellulose structure. The paste of raw material and phosphoric acid is dried and then carbonized, usually in a rotary kiln, at a relatively low temperature of 400-500°C. On carbonization, the chemical acts as a support and does not allow the charcoal produced to shrink. It dehydrates the raw material, resulting in the charring and amortization of the carbon, thereby creating a porous structure and an extended surface area. Activated carbons produced by this method have a suitable pore distribution to be used as an adsorbent without further treatment. The process used means that the activated carbons are acid washed carbons although they have a lower purity than specifically acid washed steam activated carbons. This chemical activation process normally yields a PAC. If granular material is required, granular raw materials are impregnated with the activating agent and the same method is used. GACs produced have a low mechanical strength, and are not suitable for many gas phase uses. Chemical Weekly April 20, 2010

In some cases, chemically activated carbons are given a second activation with steam to impart additional physical properties. Activated carbon from coconut shell Coconut shell based activated carbon units generally adopt steam activation to produce good quality of activated carbon.

coal takes place at the internal surface area, creating more sites for adsorption. The temperature in the process of activation is very important: Below 900°C the reaction becomes slow and uneconomical; above 1100°C the reaction becomes diffusion-controlled and therefore takes place on the outer surface of the charcoal, resulting in loss of charcoal. Typical machinery used in a activated carbon plant include: jaw crusher, hammer mill, vibratory feeder, elevator, carbonization kiln, soaking tanks, cyclones, rotary kiln with heat recovery unit, coolers, centrifuge, rotary dryer, micro-pulveriser, sieving machine, pneumatic filling machine etc.

The process of activation is carried out in two stages. First the coconut shell is converted into shell charcoal by carbonization process, which is usually carried out in mud-pits, brick kilns and metallic portable kilns. The coconut shell charcoal is activated by reaction with steam at a temperature of 900-1100°C under controlled atmosphere in a rotary kiln. The reaction between steam and char-

Activated carbon from coal The coal is first dried at a temperature sufficiently high to effect removal of moisture, but below the temperature at which contained volatile matter vaporises. The dried coal is then heated to an elevated temperature in a substantially non-oxidizing atmosphere to volatilise and remove the contained volatile matter and produce a char. The char is subjected to hydrogenation at an elevated temperature and pressure for a time sufficient to form activated carbon characterized by a BET surface area of at least about 200-m2/gm and an iodine number of at least about 400.

Table 1 Project cost of a 10-tpd coconut shell based activated carbon plant [Rupees lakh] Item Building -12,000 sq ft Plant & machinery Preliminary & pre-operative expenses Contingencies Working capital (margin money)

Cost 70 300 50 25 50

Note: Land requirement of about 1 acre has been left out of the project cost Source: Coconut Development Board

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Special Report Waste tyre utilisation The All Japan Environmental Preservation Association, jointly with the Osaka Municipal Industrial Experiment Station, has developed a waste tyre pyrolysis and activated carbon manufacturing technology.

The association established JCA Ltd. in Kyushu (Japan) which, in turn, constructed a new plant equipped with three pyrolysis systems and one activated carbon manufacturing system. The plant was put into operation in November 1993 and is presently shipping out deodorants for household use. Reactivation of used activated carbon After an activated carbon’s adsorptive capacity has been exhausted, it can

be rejuvenated by thermal reactivation. In the reactivation process, the spent activated carbon is heated in furnaces devoid of oxygen using steam as a selective oxidant. The adsorbed organics are either volatilized from the activated carbon or pyrolysed to a carbon char. The volatilized organics are destroyed in the furnace’s afterburner and acid gases are removed by means of a chemical scrubber. The hightemperature reaction with steam serves to restore the adsorptive capacity of the activated carbon. Chemical regeneration involves treatment with acids or alkalis. It can be used for GACs saturated with certain organic acids. The most widely used chemicals are sodium hydroxide, potassium hydroxide and hydrochloric acid. Chemical regeneration is generally used when only single adsorbates need to be removed or recovered. This treatment can restore only partial activity to carbons loaded with a heterogeneous mixture of adsorbates, such as those normally present in industrial streams or effluents. Biological regeneration has also

Table 2 Types of activated carbon Property Micropore Macropore Hardness Ash Water soluble ash Dust Reactivation Apparent density Iodine No. Source: Carbochem

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Coconut High Low High 5% High Low Good 0.48 g/cc 1100

Coal High Medium High 10% Low Medium Good 0.48 g/cc 1000

Lignite Medium High Low 20% High High Poor 0.4 g/cc 600

Wood Low High N/a 5% Medium N/a None 0.35 g/cc 1000

been utilized to treat carbons used in purification of textile mill and oil refinery wastewater. Through reactivation the spent activated carbon can be recycled for reuse, eliminating the costs and long-term liability associated with disposal. The environmental benefits of a reactivated product over a virgin carbon are an efficient, cost-effective alternative, where appropriate. The number of times GACs can be regenerated and the periods between regeneration vary significantly depending on the type of carbon and on its application. In solvent recovery, GAC can be used for up to 5,000 cycles. Properties of activated carbon A wide variety of activated carbons are produced, which exhibit different characteristics, depending upon the raw material and activation technique used in production. Understanding both the absorptive and physical characteristics of the material is very important in selecting the right activated carbon for a specific application. Adsorptive characteristics Surface area The surface area – measured using nitrogen gas – is a measure of the extent of the pore surface developed within the matrix of the activated carbon. It is used as a primary indicator of the activity level, based on the principle that the greater the surface area, the higher the number of adsorptive sites available and hence more reactive the activated carbon. Pore size distribution The determination of the pore size distribution of an activated carbon is an extremely useful way of understanding the performance characteristics of the material. Chemical Weekly April 20, 2010

Special Report The pore size in activated carbons can be divided into:

Micropores: Radius < 1-nm;

Mesopores: Radius 1-25-nm; and

Macropores: Radius > 25-nm. The macropores are used as the entrance to the activated carbon, the mesopores for transportation and the micropores for adsorption. The porosity of the activated carbon is measured by the extent of adsorption of iodine from a solution, or by the adsorption of saturated carbon tetrachloride vapour. Activated carbon does not bind well to certain chemicals, including lithium, alcohols, glycols, ammonia, strong acids and bases, metals and most inorganic minerals, such as sodium, iron, lead, arsenic, fluorine, and boric acid. Activated carbon does adsorb iodine very well and in fact the iodine number, mg/g, (ASTM D28 Standard Method test) is used as an indication of total surface area. Physical characteristics Important physical characteristics of activated carbons are hardness, bulk density and particle size distribution. Hardness There are large differences in the hardness of activated carbons, depending on the raw material and activity level.

Bulk density Bulk density should be carefully considered when filling fixed volumes, as it can have considerable commercial implications.

tions, water purification, recovery of solvents, recovery of gold etc. It is also used in gas masks and a wide range of filters for war gases and nuclear fall outs.

Particle size distribution The finer the particle size of an activated carbon, the better the access to the surface area and the faster the rate of adsorption kinetics. In vapour phase systems, this needs to be considered against pressure drop, which will affect energy cost. Careful consideration of particle size distribution can provide significant operating benefits.

Adsorption on GAC is finding growing use as an effective and economical process for purifying liquids by separating low concentrations of absorbable molecules from liquids. Examples of some large volume applications of this process are the de-colourisation of sugar solutions; removal of taste and odour from potable water; and the removal of dissolved organics from industrial and municipal waste streams.

Although the surface area of the pore structure and the adsorption capacity of all activated carbons are interrelated, the size of the surface area is not the only determinant on the adsorption capacity of a given carbon for a specific purpose. In other words, activated carbons with large total surface areas, but with a microporous structure may be effective in removing slight odour causing impurities from gases, but ineffective in adsorbing large colour-forming compounds from solutions. This may explain the great number of types, grades, and shapes of activated carbon available. Applications Activated carbon is extensively used in the process of refining and bleaching of vegetable oils and chemical solu-

Table 3 Typical properties of activated carbon Parameter pH Value Methylene value adsorption [mg/gm] Adsorption capacity as % by mass (min) Moisture (max) Ash (max) Hardness Source: Coconut Development Board

Chemical Weekly April 20, 2010

Value 6.5-7.5 190-350 45% 5% 5% 90%

Activated carbon can be used as a substrate for the application of various chemicals to improve the adsorptive capacity for some inorganic (and problematic organic) compounds such as hydrogen sulphide (H2S), ammonia (NH3), formaldehyde (HCOOH), radioisotopes (Iodine-131) and mercury (Hg). This property is known as chemisorption. Activated carbon is used to treat poisonings and overdoses following oral ingestion. It prevents absorption of the poison by the gastrointestinal tract. Activated carbon has become the treatment of choice for many poisonings, and other decontamination methods such as ipecac induced emesis or stomach pumps are now used rarely. Activated carbon filters can be used to filter vodka of organic impurities. Since the activated carbon does not bind well to alcohols, the percentage of ethanol is not significantly affected, but the carbon will bind to and remove many organic impurities, which can affect colour, taste and odour. Potable water currently is the largest end-use market for activated carbon, accounting for 46-kt or 37% of 187

Special Report Table 4 Applications of activated carbon Industry

Description

Typical use

Portable water treatment

GAC installed in rapid gravity filters

Removal of dissolved organic contaminants, control of taste and odour problems

Soft drinks

Potable water treatment, sterilisation with chlorine

Chlorine removal and adsorption of dissolved organic contaminants

Brewing

Potable water treatment

Removal of trihalomethanes and phenolics

Semi-conductors

Ultra high purity water

Total organic carbon (TOC) reduction

Gold recovery

Operation of carbon in leach (CIL), carbon in pulp (CIP) and heap leach circuits

Recovery of gold from ‘tailings’ dissolved in sodium cyanide

Petrochemical

Recycling of steam condensate for boiler feed water

Removal of oil and hydrocarbon contamination

Groundwater

Industrial contamination of ground water reserves

Reduction of total organic halogens (TOX) and adsorbable organic halogens (AOX), including chloroform, tetrachloroethylene and trichloroethane

Industrial waste water

Process effluent treatment to meet enviromental legislation

Reduction of TOX, biological oxygen demand (BOD) and chemical oxygen demand (COD)

Swimming pools

Ozone injection for removal of organic contaminants

Removal of residual ozone and control of chloramine levels

Solvent recovery

Recovery of organic solvents to optimise process economics and control vapour emissions

Acetate fibres (acetone), pharmaceuticals (methylene chloride), film coating and printing (ethyl acetate), magnetic tape (MEK)

Carbon dioxide

Purification of carbon dioxide from fermentation processes

Adsorption of alcohols, amines and mercaptans

Industrial respirators

Adsorption of organic vapours

To meet CEN 141 standards - Type A respirators

Waste disposal

Disposal of domestic, chemical and clinical waste by high temperature incineration

Removal of heavy metals and dioxins from flue gas

Cigarettes

Incorporation as either powder or granules in filter tips

Extraction of some harmful elements of cigarette smoke, or taste and flavour control

Air conditioning

Heating, ventilation and air conditioning (HEVAC)

Airports (partially combusted fuel odours), offices (motor vehical odours), fume cupboards (solvent odours)

Composite fibres

Impregnation of powdered activated carbon into foam / fibre / non-woven substance

Air treatment, face masks and respirators, shoe insole deodorizer and water treatment

Fridge deodorizers

In situ filter units

Removal of general food odours

Source: Active Char India web site

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Chemical Weekly April 20, 2010

Special Report Table 5 Applications in the chemical industry Organic chemicals Butanediol decolorization Condensate water treatment Dry cleaning solvent purification Dye wastewater treatment Fatty acid purification Fragrance purification Fumaric acid purification High purity solvent production Hydroquinone purification Itaconic acid recovery Maleic acid purification Melamine purification Methyl isobutyl ketone purification Pentaerythritol purification Plasticizer decolorization Propylene oxide purification Sebacic acid purification Shellac decolorization Tail oil purification Tartaric acid purification Terpene purification Urea purification

Inorganic chemicals Alum purification Ammonia purification Boric acid purification Brine solution purification Cadmium cyanide purification Hydrobromic acid purification Hydrochloric acid purification Phosphoric acid purification Sodium carbonate purification Sodium hydroxide purification Sodium triphosphate purification Sulfuric acid purification Zinc chloride purification

Petrochemicals Acrylic acid purification Adipic acid purification Caprolactam purification Condensate water treatment Emission control Ethylene glycol purification Mercury removal from olefin streams Merox catalyst support Monomer purifcation Mtbe purification Perchloroethylene purification Toluic acid purification Wastewater treatment

micro-pore structures among various activated carbons available. GAC thus facilitates efficient removal of low molecular weight organics. The high retention, large surface area and low ash content makes GAC the best choice for water/waste water treatment, removal of excess chlorine and overall organics from water. GAC also finds applications in automotive canisters, air purification, filter cartridges and cigarette filters.

vegetable oil, su-gar, pharmaceutical industry etc., and to manufacture carbon tablets used for removal of poisons from the human body.

Source: Calgon Carbon Corporation

total consumption of liquid-phase applications in 2002. Demand for activated carbon in public service water is expected to grow at approximately 4.5% annually. In 2002, gas-phase applications of activated carbon accounted for 34-kt or 21% of total activated carbon consumed in the United States. Other applications of activated carbon include:

In aquariums;

Purification of alcohol;

Production of mercury sorbents;

Home water treatment;

Automotive emissions control; and

In marine tanks. GAC has the highest fraction of Chemical Weekly April 20, 2010

PAC is widely used for removal of odour and micro-pollutants. When used in waste water treatment, it helps in better process stability and improves the settling characterization of the sludge. PACs are also used in

Acid washed activated carbons, which are generally manufactured by using premium quality acids (HCl, H2SO4, HNO3, formic acid and acetic acid), as per the requirement and specification of the customers, are mainly used in the food, water purification, soft drink, beverage and pharmaceutical industries. Impregnated activated carbon is mainly used in the water filter industry, in military applications and gas purifications. The range of impreg189

Special Report nated products includes grades for acid gas removal, ammonia removal, mercury removal and formaldehyde removal. Mercury removal In March 2005, the US Environmental Protection Agency (EPA) issued a federal rule to permanently reduce mercury emissions from coalfired power plants (Clean Air Mercury Rule). In February 2008, the CAMR was overturned and sent back to the EPA to be rewritten. As of fourthquarter 2009, a deadline of November 2011 was esta-blished for the EPA to finalize the new federal mercury regulation. It is believed that a federal regulation, assuming the November 2011 deadline is met, would require compliance by 2014.

Arsenic removal Arsenic levels continue to be an important factor in the PAC business, so PAC customers are increasingly becoming more interested in comparing carbons on a performance basis rather than just a price-per-pound basis. Market trends The activated carbon business will continue to be driven by environmental regulations, principally water and air purification, especially in the mature and more industrialized areas of the world. In the next five years, environmental issues will likely become the predominant force in the markets of rapidly developing countries.

consumption was about 650-kt in 2007, slightly over estimated production of 635-kt. Growth in consumption in current markets is forecast by the report to be 5% per year through 2015. The report states that the growth would be led by water treatment applications both in the USA, to control disinfection by-products (DBPs) in drinking water, and in the industrialising countries, to upgrade the quality of drinking and wastewater. In China, 10,000 waste water treatment plants are scheduled for construction by 2010, raising the proportion of wastewater treated from 29% to 50%. The country’s demand for activated carbon in all forms is estimated at about 170-kt in 2008.

Potential new markets emerge According to Roskill, the next five years could see the emerTable 6 gence of the largest-ever EPA projected control technologies market for activated carbon – the use of PAC to Control type Pollutants Max control Projected controlled efficiency [%] installations control mercury emissions from coal-fired power plant Limestone wet scrubber Mercury, HCl Mercury – 80 125-128 flue gas in North America. HCl – 99.9 Driven by state environmental legislation in the US and Activated carbon injection Mercury, THC Mercury – 90 141-147 limitations on new power THC – 80 plant construction, this marRegenerative thermal oxidiser THC 98 12-21 ket is estimated to increase from 5,000-kt PAC in 2007 Membrane bags added to PM >99.9 17-35 to 125-kt in 2010. Growth in existing fabric filter demand for activated carbon Fabric filter PM >99.9 0-5 could accelerate to close to 400-kt in 2015 if US fedTable 7 eral legislation, requiring installation Major international manufacturers of activated carbon of 600-700 activated carbon injection systems, is introduced, the report Company Location adds. Norit Netherlands, Italy, UK & US According to Roskill, a market research firm, global activated carbon

Calgon Carbon

US, China

Carbochem Inc.

US

CarboPur Technologies

Canada

Carbon Activated Corp.

US

CPL Carbon Link

UK, Germany

Chemviron Carbon

UK

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According to Calgon Carbon Corporation (CCC), a leading producer of activated carbon in the world, the estimated market for activated carbon from mercury removal could touch approximately 75-kt by 2011 in the US alone, with demand from Canada adding another 15-kt. Chemical Weekly April 13, 2010

Special Report Table 8 Major manufacturers of activated carbon in China Anshan Active Carbon Fibre Beijing Haijian Jiechang Environmental Protection Chemicals Beijing Pacific Activated Carbon Bluesky Purification Material Datong Carbon Datong Fenghua Activated Carbon Datong Huabao Active Carbon Datong Municipal Yunguang Activated Carbon Datong Weidu Activated Carbon Plant Fuzhou Yihuan Carbon Hengxing Active Carbon Huairen Huanyi Purifying Materials Huaiyushan Activated Carbon Group Huatai Activated Carbon Ebian Huaxin Active Carbon Plant Jianou Zhixing Activated Carbon JingMao Activated Carbon Kaihua Xingda Chemical Kaihua Xinghua Chemical Plant Kuraray Chemical Environmental Industry Longyan Wanan Activated Carbon Mindong Lianyi Group Nantong Sutong Carbon Fibre Ningxia Blue-White-Black Activated Carbon Ningxia Fengyuan Activated Carbon Ningxia Guanghua-Cherishment Activated Carbon Ningxia Henghui Activated Carbon Ningxia Huahui Activated Carbon Ningxia Taixi Activated Carbon Ningxia Xingsheng Coal and Activated Carbon Shanghai Mebao Activated Carbon Shanghai Xingchang Activated Carbon Shanxi Xinhua Chemical Shanxi Zuoyun Yunpeng Coal Chemistry Shenhua Ningxia Coal Industry Group Taining Jinhu Carbon Tianchang (Tianjin) Activated Carbon Xuanzhong Chemical Industry Zhuxi Activated Carbon Chemical Weekly April 20, 2010

Another driver for activated carbon in the US market is the Stage 2 Disinfection Rule in the US for potable water treatment. Promulgated by the US-EPA in 2006, this rule sets maximum levels of DBPs, which are potentially harmful compounds formed when chlorine combines with naturally occurring materials in drinking water. Activated carbon is an effective way of removing DBPs, and the estimated market size for this application is annually about 23-kt of GAC in the US alone. Total world demand for activated carbon therefore has the potential to rise by nearly 10% per year to 1.36-mt in 2015, with mercury emission control accounting for 30% of projected total consumption. New projects The tight market balance for activated carbon in 2007-08 and forecast growth rates of up to 10% per year in world demand have encouraged plans for significant new capacity. According to Roskill forecasts, projects underway or under consideration could raise capacity by over 260-ktpa, equivalent to around 25% of installed capacity in 2007. Over 85% of capacity is planned in the US and China and much of the new US capacity is aimed at the mercury control market. Companies planning new or expanded coal based capacity include Norit, Calgon Carbon and ADA-Environmental Solutions (ADA-ES) in North America and SNCIG in China, the report reveals. Norit, already the world’ s largest producer of PAC, is expanding capacity in the USA and has recently formed a joint venture with Prairie Mines and Royalty to construct the first activated carbon plant in Canada. CCC, the world’s largest GAC producer, has a multi-stage programme to raise capacity by up to 136-ktpa of powdered 191

Special Report

Company Indo German Carbons Ltd. Active Char Products P. Ltd. Adsorbent Carbons Raj Carbons Genuine Shell Carb P. Ltd. Agni Carbon Blumen Carbon Vishal Special Carbon India Ltd. Coco Carbon Activators

Table 9 Some Indian manufacturers of activated carbon Location Capacity [tpa] Cochin, Kerala 14,000 Cochin, Kerala 5,000 Tuticorin, Tamilnadu Tuticorin, Tamilnadu 3,500 Coimbatore, Tamilnadu Faridabad, Haryana 1,200 Erode, Tamilnadu 1,200 Thane, Maharashtra Bangalore, Karnataka

Feedstock Coconut shells Coconut shells Coconut shells Coconut shells Coconut shells Wood charcoal & coconut shells Coconut shells Wood charcoal Coconut shells

Source: Coconut Development Board; Estimates: Company websites

Table 11 Indian demand-supply scenario for activated carbon

Table 10 Demand for activated carbon in India by end-use Sector Vegetable oils Pharmaceuticals Plasticisers Glucose/dextrose monohydrate/sorbitol Miscellaneous Total

Year 2001-02 2002-03 2003-04 2004-05 2005-06 2006-07 2007-08 2008-09

Demand [kt] Share [%] 35 70 3 6 2 4 2 4 8 16 50 100

Kilotons Capacity

80

Production

70

Imports

5

Exports

25

Domestic demand

50

Table 12 Imports and exports of activated carbon from India [Quantity in tons; value in Rs. Million] Exports Imports Quantity Value Quantity Value 3,250 127.85 860 101.11 6,459 257.93 1,309 161.68 7,282 272.25 2,900 315.91 9,689 369.02 2,738 365.33 12,459 666.87 2,386 292.51 14,429 715.75 3,788 392.00 18,834 817.64 4,895 470.64 24,654 1,329.12 4,827 616.42

Source: DGCI&S, Kolkata

material and may construct a new plant outside the USA in the longer-term. It is restarting closed production lines, converting GAC production capacity to PAC, and also mulling new production lines at existing lines to meet this demand. 192

A new entrant to the market, ADAES and its equity partner, Energy Capital Partners, formed a joint venture company called ADA Carbon Solutions to build an activated carbon plant in Coushatta, Louisiana (UA). Construction began

in September 2008 and is expected to be completed by the middle of 2010. This $350-mn facility will produce between 56-80-ktpa of activated carbon to be used for controlling mercury emissions from coal-fired power plants. Chemical Weekly April 20, 2010

Special Report New capacity in China is likely to based activated carbon project, with a be restricted to companies with captive total investment of RMB 1.5-bn, which coal supplies. In June 2007 Shenhua is expected to be completed in two or Ningxia Coal Industry Group (SNCIG) three years. The first-phase project started construction on the 50-ktpa has an investment of RMB 376-mn. In coal-based activated carbon project June 2008, the company brought online in Shizuishan, Ningxia. It is the first about 10-ktpa of capacity online. As phase of the company’s 250-ktpa coal- coconut shell-based material becomes more competitive, Table 13 expansions in actiTop-10 suppliers of activated carbon into India vated carbon capa[Quantity in tons; value in Rs. Million] city are underway in Quantity Value Indonesia, India and China 2,274 144 the Philippines, some France 735 126 involving Chinese inUSA 490 36 terests. Haycarb, the largest producer of Netherlands 279 42 coconut shell-based Germany 252 57 activated carbon Japan 214 17 worldwide, plans to Malaysia 203 11 expand group capaSri Lanka 133 11 city to 30-ktpa by 2010. Several operaThailand 102 5 tions, especially in UK 73 10 the USA and AusIndonesia 42 2 tralia, have been Others 98 10 proposed in the past for activated carbon Total 4,895 471 production from nonSource: DGCI&S, Kolkata conventional raw Table 14 materials. To date Top-10 destinations for exports of activated carbon only one, AgriTecfrom India Sorbents’ plant based [Quantity in tons; value in Rs. Million] on rice hull ash, has Quantity Value entered commercial production. Tighter USA 3,704 168,334 activated carbon supUK 1,608 81,809 plies may encourage Netherlands 1,480 61,485 further investment in France 1,332 61,309 plants processing alSri Lanka 1,314 46,139 ternative raw materials in future. Germany 1,309 54,694 Saudi Arabia 917 35,757 Rising prices In 2007-08, tightSouth Africa 899 36,795 ening availability Italy 833 27,580 and rising production Australia 660 30,545 costs led to sharp Others 4,779 213,194 price rises for activaTotal 18,834 817,642 ted carbon, a market characterised by surSource: DGCI&S, Kolkata Chemical Weekly April 20, 2010

plus capacity and stable pricing over the previous decade. Prices of coal-based grades rose by up to 80% between the beginning of 2007 and mid-2008, with the tight market balance also exerting pressure on prices of other grades of activated carbon. Through the early 2000s, price increases were restrained by the large surplus capacity worldwide, following capacity expansions in Asia, especially China. In 2008 production in China, which accounts for some 40% of both world activated carbon capacity and exports, fell. The reduced supply, the imposition of anti-dumping duties on US imports of steam-activated carbon from China since spring 2007, elimination of VAT (value added tax) rebates for Chinese exporters, currency fluctuations, and rising energy and freight rates, have all exerted upward pressure on activated carbon prices (Table 7&8). Indian scenario The Indian activated carbon industry is characterised by a number of small producers. Some estimates put the number of producers at about 50. Total installed capacity is about 80-ktpa. Coconut shell is an important raw material for activated carbon manufacture, especially in the southern states. Kochi-based, Indo German Carbons Ltd. claims to be the largest player in the country and the third largest in the world in the production of coconut shell-activated carbon. It is also planning to expand capacity to 20,000-tpa from the present 14,000-tpa (Table 9). Demand-supply trends Total domestic demand for activated carbon is about 50-kt, with the vegetables oil sector the largest enduse sector, accounting for some 35-kt of demand. Domestic demand growth is about 10% per annum (Table 10-14). 193