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VATIS Update Waste Management . Mar-Apr 2004

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Waste Management Mar-Apr 2004

ISSN: 0971-5665

VATIS Update Waste Management is published 4 times a year to keep the readers up to date of most of the relevant and latest technological developments and events in the field of Waste Management. The Update is tailored to policy-makers, industries and technology transfer intermediaries.

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Energy
VATIS Update Non-conventional Energy Jul-Sep 2017
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VATIS Update Biotechnology Jul-Sep 2017
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VATIS Update Waste Management Oct-Dec 2016
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VATIS Update Food Processing Oct-Dec 2016
Ozone Layer
Protection
VATIS Update Ozone Layer Protection Sep-Oct 2016
Tech
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Asia-Pacific Tech Monitor Oct-Dec 2014

Contents

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IN THE NEWS

Waste recycling rate low in Thailand

A report commissioned by the World Bank has unveiled that Thailand recycles just 11 per cent of its total waste, compared with Australias 36 per cent. According to the latest Thailand Environment Monitor, presently Thailand churns out twenty million tonnes of waste every year and this figure is expected to grow rapidly. Most of this waste goes into unofficial dumping sites. The report addresses six key waste challenges for the future and lists some policy alternatives to help overcome these obstacles, including the promotion of recycling, establishing procedures for hazardous wastes and regulations covering industrial waste.


Website: www.cansmart.org 

Philippines strives to eliminate POPs

A proposal that aims to eliminate persistent organic pollutants (POPs) in the Philippines has been sent by the Department of Environment and Natural Resources (DENR) to the Global Environment Facility (GEF) for funding. Under this programme, a facility will be established to treat about 300 t/y of toxic chemicals as well as store nearly 5,554 t of polychlorinated biphenyls (PCBs). POPs are chemical substances that persist in the environment, bio-accumulate through the food web and pose a risk of causing adverse effects to human health and the environment. The Stockholm Convention came out with the 12 POPs initial list, namely hexachlorobenzene, mirex, endrin, DDT, chlordane, toxaphene, heptachlor and dieldrin (all pesticides), PCBs (industrial chemicals), dioxins and furans (unintended by-products).


DENR, through the Environmental Management Bureau, is at present formulating a POPs Implementation Plan to address issues raised during POPs management. The plan lists how the nation will comply with its obligations by phasing out POPs sources as well as contaminated areas. Funds have been made available for the planning stage through the Philippine Enabling Activity Project, currently facilitated by GEF through the United Nations Development Programme. This scheme is part of the initial assistance for the Philippines to meet its obligations under the Stockholm Convention.


Website: www.denr.gov.ph 

Latest additions to PIC list

The Intergovernmental Negotiating Committee for the Rotterdam Convention on Prior Informed Consent (PIC) procedure for some hazardous chemicals and pesticides in international trade has formally adopted decisions to add two new pesticides and four forms of asbestos to the PIC list. The delegates agreed to postpone a decision on chrysotile asbestos, which represents 94 per cent of global asbestos use, until a one-day meeting in Switzerland on 18 September 2004.


Amosite, anthophyllite, actinolite and tremolite are the four forms of asbestos. The two pesticides are DNOC and dustable powder formulations containing a mix of pesticides, such as benomyl (at/above 7 per cent), carbofuran (at/above 10 per cent) and thiram (at/above 15 per cent). 


Contact: Mr. Michael Williams, United Nations Environment Programme, Geneva, Switzerland. Tel: +41 (22) 9178 242 / 244 / 196; Fax: +41 (22) 7973 460; E-mail: michael.williams @unep.ch; Or Mr. Erwin Northoff, FAO, Rome, Italy. Tel: +39 (06) 5705 3105; Fax: +39 (06) 5705 4974


E-mail: erwin.northoff@fao.org 


Website: www.unep.ch 

Air pollution pact in Southeast Asia

The ASEAN Agreement on Transboundary Air Pollution entered into force on 25 November 2003 following ratification by Thailand, reports the ASEAN Secretariat. A press release from the Secretariat states that the pact, endorsed by the ten member nations of ASEAN in 2002, is the worlds first regional arrangement binding a group of contiguous countries to tackle transboundary air pollution resulting from forest fires. The agreement stipulates that it will become operational 60 days after the sixth ratification. Brunei, Malaysia, Myanmar, Singapore and Viet Nam had earlier ratified the treaty.


Parties to the treaty have agreed to cooperate in preventing and monitoring air pollution, control sources of fires through devising early warning systems, exchange information and technology, and provide assistance. Member countries are required to promptly respond to a request for relevant information sought by those affected by transnational air pollution, when the pollution originates from that country. ASEAN members are: Brunei, Cambodia, Indonesia, Lao Peoples Democratic Republic, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Viet Nam.


Viet Nam Infoterra Newsletter
October-December 2003

Waste purification plan for hospitals

In Viet Nam, data available with the Ministry of Health reveal that about 28.5 t/d of solid waste is discarded by hospitals. The two biggest cities Hanoi and Ho Chi Minh City discharge a total of 10 t/d. A French project has been implemented with the goal to treat 100 per cent of solid wastes in state-owned healthcare units and 30-50 per cent from private facilities by 2010. Approximately 46 incinerators will be installed at treatment centres around the country. Viet Nam is expected to spend about US$21.5 million over the next ten years, with around US$300,000 for each province.


Viet Nam Infoterra Newsletter
October-December 2003

Steel waste used to lay new roads

Singapore is looking into using by-products of steel-making for use in paving roads as part of the nations effort to reduce waste. Officials are now testing ladle furnace slag, waste resulting from steel processing, for possible use as road asphalt. Last year, Singapore used incinerator ash to build roads in a recycling experiment. The Environment Minister has stated that the goal is to create a zero landfill, zero waste city-state.


Website: www.recyclingtoday.com 

China amends law on preventing solid waste pollution

In China, the Standing Committee of the 10th National Peoples Congress (NPC) has given its approval for a proposal, recommended by NPCs Environment and Resources Protection Committee (ERPC), to amend the solid waste pollution prevention law. ERPC has stated that electronic waste pollution is a serious concern, together with the nations high-gear economic development and the more frequent use of electronic products. Household appliances often contain environmentally harmful materials and if these are directly buried or burned, air, soil or water could be severely polluted.


On the subject of recycling waste industrial products, including waste electronic products, the Standing Committee of the 9th NPC brought out a legislation in 2002, that made retrieval of post-consumer industrial products compulsory. The Standing Committee of the 10th NPC will regulate the disposal procedures of some new types of solid waste by altering the present law.


Website: www.english.peopledaily.com.cn 

LGUs focus on solid waste management

More than 65 local government units (LGUs) in the Philippines have opted to convert their existing dumpsites into controlled disposal facilities, in tune with the Ecological Solid Waste Management Act. The Secretary to the Department of Environment and Natural Resources (DENR) opined that the ecological solid waste management programme, undertaken by the DENR and government and non-governmental organizations, has resulted in increased recycling activities pertaining in major cities and municipalities. Ms. Elisea G. Gozun stated that Making the change from open dumpsites to acceptable disposal facilities as provided for in the law is being intensified by DENR with the support of local governments. We have already identified 83 potential sanitary landfill sites nation-wide to effectively manage the disposal of the countrys wastes.


Also, according to the National Solid Waste Management Commission (NSWMC), Metro Manila has two controlled disposal facilities, which are commissioned to accommodate wastes collected from majority of the LGUs (around 3,000 t/d). On the other hand, the Payatas dumpsite utilized exclusively by the Quezon City government handles an average of 1,500 t of solid waste. NSWMC adds that the remaining wastes are disposed through open dumps, while some find their way into waterways, creeks and estuaries. NSWMC statistics indicate that Metro Manila generated some 5,245 t/d of garbage or 14.5 per cent of waste generated nationwide. While the collection efficiency is in urban areas 73 per cent, only 40 per cent has been achieved in rural areas. At present, there are 721 open dumpsites, 292 MRFs, 151 pre-recycling and recycling plants, 141 composting facilities and 65 
controlled dumpsites nationwide.


Website: www.denr.gov.ph 

Hospitals comply with Clean Air Act

In the Philippines, a report submitted by the Department of Health (DOH) reveals that compliance of hospitals nationwide with the Clean Air Act is gaining ground slowly. According to DOH, of the 72 DOH hospitals countrywide, around 33 healthcare facilities that incinerate the wastes generated by them have stopped incineration while about 23 special and speciality hospitals resorted to microwave, autoclave or pyrolysis. The report also cited that about 64 hospitals are adopting different kinds of treatment, such as microwave or chemical disinfection and privately contracted treatment through autoclave or pyrolysis.


The use of incinerators was banned on 17 July 2003, as provided for in the Clean Air Act and its implementing rules and regulations. Section 20 of the act defines incineration as the burning of municipal, biomedical and hazardous wastes, which process emits poisonous and toxic fumes. The law also promotes the use of alternative non-burn techniques such as size reduction and compaction, autoclave and microwave for thermal technologies, which are among the most common methods presently employed.


Website: www.denr.gov.ph 

Scrap electronics recycling systems to be set up in China

The National Development and Reform Commission (NDRC), China, has selected Zhejiang province and the City of Qingdao as the first two locations for establishing recycling systems for scrap electronic products. Installation and operation of these recycling centres will provide practical references for the government in formulating corresponding regulations and industrial standards pertaining to recycling electronics waste. NDRC has stated that the recycling systems will be operated under market-oriented disciplines. The government will provide favourable policies to support the recycling industry.


Under a programme developed by NDRC and Chinas environmental authorities, electronics companies will be required to reclaim their scrap electronic products, including mobile handsets, PCs, refrigerators, washing machines and air-conditioners. This scheme would also relieve the heavy burden on the governments for recycling waste electronic products, which contain harmful materials such as cadmium, chromium, and lead. It is estimated that about 4 million refrigerators, and 5 million each of television sets and washing machines are discarded annually.


Website: www.recyclingtoday.com 

Industrial waste incinerator developed in Viet Nam

A team of researchers at the Hanoi Construction Universitys Urban and Industrial Environment Centre, Viet Nam, have successfully developed the countrys first industrial waste incinerator. The new system costs about one-third that of an imported model. It has the capacity to combust 150 kg/h of industrial wastes.


Viet Nam Infoterra Newsletter
October-December 2003

New regulations on used batteries

In China, five ministries have jointly issued a regulation aimed at preventing pollution caused by spent batteries. Detailed stipulations are being made on each step in battery recycling collection, categorizing, transportation, storage and utilization. Used batteries contain toxic heavy metal elements such as lead, mercury, cadmium and nickel, as well as acid and alkali electrolyte solutions, which as pollutants may cause damage to human health and the environment.


Website: www.zhb.gov.cn 

China to label medical wastes

In China, the Health Ministry and the State Environment Protection Administration (SEPA) have together promulgated a regulation that makes it mandatory for all medical wastes to be stored in safe containers with special labels to prevent them from mixing up with other wastes during disposal. The new statute stipulates that packages containing infectious wastes and sharp instruments must carry a warning mark. Additionally, all packages have to meet certain technological requirements e.g. they should not contain PVC.


Website: www1.chinadaily.com.cn 

China to establish centres for disposing medical wastes

In China, the State Environmental Protection Administration (SEPA) has submitted a plan to the State Council for establishing about 200-300 medical waste disposal centres over the next 2-3 years. Officials and experts with the Ministry of Health and the Beijing municipal government expressed that this move is a lesson from the outbreak of SARS, which claimed 394 lives. Sources with the Beijing municipal government reported that two new medical waste disposal facilities would be built by the end of 2004, which are expected to dispose about 60 t/d of wastes.


Website: www.news.xinhuanet.com

PLASTIC WASTES

Recycling plastics using pressurized gasification process

In Japan, Ube Industries Ltd. and Ebara Corp. have jointly developed a two-stage pressurized gasification method to process waste plastics. The novel technique breaks down solids present in waste materials to hydrogen and carbon monoxide, providing new opportunities for their use as raw material for chemicals. The system directly links an internally circulating fluidized bed gasification furnace (low-temperature gasification) to a circular combustion furnace (high-temperature gasification), thus enabling mixed plastic wastes to be processed. Some notable features of this system are:
  • All types of plastic wastes and materials like RDF produced from municipal wastes and shredder residue can be processed without separating plastic, whichcontains chlorine;
  • Preparation requires only the removal of large non-combustibles and metals. Using sand circulation, the low-temperature gasification unit removes metals and fine non-combustibles mixed with the plastics;
  • Dioxins are completely decomposed in the high-temperature gasification furnace where temperatures exceed 1,300C. Additionally, dioxin re-synthesis is inhibited since the generated gas is rapidly cooled and passes for a brief moment through the range where dioxins could re-synthesize;
  • Ash present in the waste material is stripped as water-cooled slag for use in construction materials; and
  • The generated gas, purified and refined with an alkali water solution, can be used to obtain raw materials for chemicals.

Contact: Ube Industries Ltd., 1-2-1, Shibaura, Minato-ku, Tokyo 105 8449, Japan. Tel/Fax: +81 (3) 5419 6224/6274; Website: www.ube.co.jp ; Or Ebara Corp., 1-6-27, Konan, Minato-ku, Tokyo 108 8480, Japan. Tel: +81 (3) 5461 6111; Fax: +81 (3) 5461 5780


Website: www.ebara.co.jp 


Website: www.nett21.gec.jp 

Breakthrough in plastics recycling

Researchers at the Massachusetts Institute of Technology, the United States, have developed a process to mould plastics into shape without exposing them to heat. This allows reprocessing without damaging the material at the molecular level, thus making the large-scale recycling of plastics more feasible. Dr. Assender, a materials scientist at the University of Oxford, opines that the new process would have to be industrially viable and there were other factors curtailing large-scale recycling.


Website: www.onyxgroup.co.uk 

Coke ovens used to recycle waste plastic

In Japan, as part of its voluntary plan to save energy, the Japan Iron and Steel Federation has proposed a 10 per cent energy reduction by 2010 with 1990 as the basis. It has further put forward an additional target of 1.5 per cent energy savings by using waste plastics as a metallurgical raw material. Coke-making process is considered to be a promising area in which thermal decomposition of waste plastics is applicable since the process involves coal carbonization in a high-temperature, reducing atmosphere. Tests have proved the feasibility of chemical recycling to recover coke, tar, light oil and gas from general waste plastics mixed in coal by carbonization in ovens 
without deteriorating coke quality.


Recycling waste plastics by the Coke Oven from Waste Plastics to Chemical Raw Materials Method involves pretreating plastic containers and packaging for crushing, removal of foreign materials and briquetting. Next, they are mixed with blended coal, charged into coke ovens and decomposed at 1,200C (max.) without oxygen supply to obtain approximately 20 per cent coke, 40 per cent tar and light oil, and 40 per cent of COG, a hydrogen-rich gas. The recovered coke is used to reduce iron ore in a blast furnace while tar and light oil are used as raw materials or plastics, etc. COG can be used in power facilities as a clean energy source. This method is approved as a chemical recycling technology that fulfils the domestic Containers and Packaging Recycling Laws. Nippon Steel has been utilizing this method since the year 2000.


Nippon Steel Technical Report,
No. 87, January 2003

Recycling mixed polymers

Polywood Inc., the United States, utilizes mixed recycled plastics to produce fibre-reinforced structural profiles for railroad ties, I-beams and decks. In Polywoods technique, the fibre reinforcements are not added but created inside the profiles during extrusion. This patented technology was developed at Rutgers University. In the late 1980s, a Ph.D. student discovered that extruding incom-patible blends of polystyrene (PS) and polyethylene (PE) in the right proportions creates a co-continuous blend of matrix resin reinforced with intertwined fibres. The in situ composite exhibits good compressive strength. This effect is produced by mixing 20-35 per cent of a high-melt strength PS with recycled HDPE.


PE/PS ties behave differently from wood. When new wooden ties are installed on a rail bed of crushed rock, trains passing over the ties press them into the rock, creating dents which lock the ties in place. However, plastic ties do not dent so easily. The company embosses the bottom of its ties with dimples to give the rocks a grip. Additionally, it has been observed that the mechanical properties of the plastic ties improve over time. The compressive modulus for a 


Polywood tie is 2,600 psi when new and 3,100 psi after 20 years simulated ageing. In contrast, new wood ties start at 3,200 psi and drop to 1,000 psi after ageing. Polywood ties are made by compounding HDPE and PS in-line with two types of intrusion moulding. It uses two formulations one high in PS and stiffer as it has a higher fibre content, the other high in HDPE and less rigid, for use in industrial pallets and decking. Polywood uses manufacturing wastes from producers of food trays and institutional packaging. Following tests conducted by six research institutes, Polywoods RR ties were qualified in 2000 by the Chicago Transit Authority for embedded and elevated track.


Website: www.plasticstechnology.com 

Decomposition of plastic wastes

In Japan, Kobe Steel Limited has developed technology to decompose waste plastics using supercritical water, a fluid that is over the critical point of vapour-liquid coexistence state. The density of supercritical water can be continuously controlled between gas- and liquid-like values by manipulating its temperature and pressure. The properties of supercritical water enable decomposition of substances with ether, ester and isocyanate bonds which are condensation polymerization plastic to their monomer when supercritical water is used as the reaction solvent. It has been observed that PET decomposes into its monomer in supercritical water on hydrolysis in batch-continuous apparatus, and ethylene glycol and terephthalic acid can be recovered.


Website: www.nett21.gec.jpWhen supercritical water is used as reaction solvent, the temperature of water used as reaction medium is more than the pyrolysis condition of plastics. The addition polymerization plastic is converted to oil in supercritical water. In the case of mixed wastes, comprising condensation polymerization plastic and addition polymerization plastic, the former is selectively decomposed into its monomer in a short time, while the latter is continuously converted to oil only after monomerization of the condensation polymerization plastic. 


Contact: Kobe Steel Ltd., Japan. 


Website: www.kobelco.co.jp 

Industrial grinders for plastics and waste

V.M.C. Impianti, Italy, offers milling machines designed for continuous and intensive cycles in industrial 
milling procedures, specially plastic and other wastes. Constructed using quality materials, the new systems feature a robust structure and precision cutting blades. Milling efficiency is increased by an automatic-drive drawer, which presses the material against the blade until it has been completely milled. All units include sophisticated control equipment to regulate the automatic-drive function, adapting it to the type of material to be shredded. The tool (plate) applied to the blade can be utilized on six edges by means of a simple rotating mechanism prior to replacement.


A high-capacity loading hopper, fabricated using die-cast sheet metal, is welded on to a tubular ring, to which special dust-proof and screened 
guide shoes are fixed. The hopper movement, which enables untreated material to be pushed towards the rotor, is controlled by two hydraulic cylinders. An adjustable non-return steel sheet baffle plate is bolted to the inside of the hopper. Drive belts perform the delicate function of a clutch, which protects the reduction unit and motor from knocks/shocks, that may occur during the grinding step. Machine operation is controlled by a sensor-based PLC panel for automatic adjustment of the hopper thrust, avoiding stress on the electric motor. 


Contact: V.M.C. Impianti, Borgoricco, Padova, Italy. Tel: +39 (049) 9335 981; Fax: +39 (049) 9335 982; 


E-mail: info@vmcimpianti.it


Website: www.vmcimpianti.it 


Website: www.recyclinginternational.com 

New plastics recycling process

Advanced Plastic Recycling (APR), Australia, offers eco-friendly technology to recycle post household, commercial and industrial plastics waste. These wastes are mixed, fed into the processor and rejuvenated as new products. The APR process operates without the need for sorting, washing or cleaning. While impurities such as metals, sand and grit are removed, softer metals (e.g. aluminium), contaminates and alien bodies like paper and contents of the containers, e.g. sauce and butter, can be accommodated.


Mixed plastic wastes are granulated and converted into an agglomerate. Later on, capitalizing on the unique qualities of plastics to change when heated, the material is pumped or pressure-filled into a mould and then cooled with water. The material thus obtained is pliable and easy to mould into any required shape. 


Contact: Advanced Plastic Recycling, Lot 9, 540, Churchill Road, Kilburn, South Australia 5084, Australia. Tel: +61 (8) 8359 4999; Fax: +61 (8) 3594 988


E-mail: enquiries@a-p-r.com 


Website: www.a-p-r.com.au 

Building material from waste plastics

Oy Mine Re Plast Ltd., Finland, is offering a patented technology for producing building material from a mixture of unscreened thermoplastic waste and minerals. This innovative process recycles unsorted thermoplastic wastes from the packaging or construction industry, electrical and electronics industry as well as plastics not suitable for recycling with conventional methods. Mineral raw material used in this process are natural gravel or crushed gravel, mineral from construction locations, production sites, mining operations, etc. Waste plastics, oil, wood and tyres are used as supportive fuel for biogas or heavy fuel oil.


These raw materials are primarily recyclable wastes, but end up unused in dump sites. They are transformed into slabs, tiles, boards or elements that are used exclusively or along with construction materials. The new products can be employed in moisture-proofing or in moisture-resistance applications, traffic noise reduction, etc. Since they do not absorb moisture, they do not decay easily. 


Contact: Oy Mine Re Plast Ltd., Nuottalahdentie 3E, Fin 02230 Espoo, Finland. Tel/Fax: +358 (9) 8842 746 


E-mail: matti.toivola@kolumbus.fi 


Website: www.kolumbus.fi 

Extrusion technology for plastic and composite products

Conenor Ltd., Finland, has designed conical extrusion technology that raises the mechanical and physical properties of a wide range of plastic and composite products such as films, pipes, cables and packaging making new value-added products possible. In the new extruder, the polymer flows along a series of spiral channels machined into the conical rotor and stator surfaces. An innovative geometry significantly lowers residence time and residence time distribution compared with conventional single- and twin-screw models. This permits improved control of the shear rate and melt temperature, eliminates thermal degradation of polymers and additives, and allows the use of higher melt temperatures. Multi-layer products can be manufactured without requiring complex and expensive dies or side extruders. Additionally, the products are seamless as no in-die melt separators are needed.


Conical extruders are suitable for products and procedures that are very demanding in terms of quality and for products made of different resins and materials that are difficult to extrude, like LCP, HFFR, high-viscous UHMW-PE, etc. Conenors extrusion system and dies are self-cleaning and completely free of dead spots. Only simple, low-cost dies are required. A variety of value-added, on-line processes can be included reactive extrusion (e.g. cross-linking PE and foaming), liquid and gas injection, mixing/compounding and orientation of discontinuous fibres and LCP. Other procedures such as sequential extrusion for encapsulated products are being developed.


A novel characteristic of Conenors conical extruder makes it ideal for use in recycling plastic waste and scrap to produce thermoplastic composites like combinations of wood fibre and plastics. 


Contact: Conenor Oy, Teollisuustie 13, Tampere, Finland. Tel: +358 (40) 8215 632; Fax: +358 (3) 2344 130


Website: www.conenor.com 


Website: www.hightechfinland.com

BIOMEDICAL/HEALTHCARE WASTES

Microwave-based disinfection system

Sanitec Worldwide Ltd. is offering a proprietary range of microwave disinfection systems for medical waste treatment. Sanitec units, housed in an all-weather steel enclosure, can be installed inside or outdoors. They require standard electric and water hook-ups only. An automated lift/load mechanism eliminates the need to lift heavy boxes or bags.


Waste is brought to the system in carts, which are then attached to the Sanitec unit and emptied into a sealed in-feed hopper. Next, waste is reduced into tiny particles utilizing a sophisticated shredding system. Grinding creates a more even waste stream that can be effectively treated at lower temperatures than feasible by using competing systems, thus eliminating the potentially harmful air emissions associated with other systems. Air from the in-feed hopper is drawn by a fan through a series of filters, including a high-efficiency particulate air (HEPA) filter and a carbon filter to control odours. Next, waste is picked up by a stainless steel screw conveyor, moistened with steam and passed through a series of microwave units.


The treated waste is then conveyed outside the unit using a secondary screw conveyor and deposited into a compactor or dumpster. A granulator for further waste reduction is optional. The process is controlled by on-board microprocessor and is monitored by computer. 


Contact: E-mail: sales@sanitecworldwide.com 


Website: www.sanitecworldwide.com 

Plasma gasification for biomedical waste

In Italy, S.T.E. and its partners are offering a new plasma gasification technology to treat biomedical and other toxic wastes. The non-incineration thermal process uses extremely high temperatures in an oxygen-starved environment to completely degrade waste matter to very simple molecules. The modular system has an extremely small footprint, compared with other disposal technologies. It can be installed within an existing superstructure or largely 
underground, which may be more desirable for aesthetic reasons.
Plasma gasification is a generic process that can accommodate any waste material liquid, gas or solid, in any form or combination and is indpendent of moisture content. It provides almost complete removal of all carbon from the waste. Furthermore, Immense volume reduction of the waste into slag is feasible up to 400:1 for boxed biomedical waste. 


Contact: S.T.E. S.r.l. - Via Sorio, 120-35141 Padova, Italy. Tel: +39 (49) 2963 900; Fax: +39 (49) 2963901 


E-mail: ste@ste-energy.com 


Website: www.ste-energy.com 

Incineration plant for biomedical wastes

Medi-Collect, Australia, is offering thermal destruction facility (TDF) for sterilizing and disposing pathogenic wastes, with simultaneous recovery of waste heat to aid thermal combustion. In the primary chamber of the TDF, waste is burned to obtain gas, which is then combusted in the secondary chamber to yield carbon dioxide (CO2) and water vapour. In the secondary chamber, the gases are burned at a higher temperature, with a retention time corresponding to the minimum temperature needed under licensed conditions.


The Medi-Collect TDF uses a two-second retention time at 1,100C. Heat exchangers are utilized in the third stage to cool exhaust gases, recovering energy to generate preheated air that is routed back to the secondary chamber. The air pollution control equipment collects particle matter, captures trace metals and organics, neutralizes the acid gases and formation of dioxins and furans in the combustion process. 


Contact: Medi-Collect, #3-7 Felspar Street, Welshpool, Perth, WA 6106, Australia. Tel: +61 (08) 9356 5737; Fax: +61 (08) 9458 6174


E-mail: info@medicollect.com.au 


Website: www.medicollect.com.au 

Sterilization of clinical wastes

Ecodas, France, offers a fully automated system to shred and sterilize clinical wastes. Waste, loaded at the top of the machine, is shredded using a heavy-duty shredder, which changes direction every 120 s. The shredded material falls by gravity into the lower chamber. Sterilization is achieved by using steam, which is maintained at a temperature of 138C and 3.8 bar pressure, for 10 minutes. Sterile fragments (8 log10 reduction) are discharged from the bottom of the machine and sent to landfill sites. The original volume is reduced by 80 per cent, safely, cost-effectively and in an eco-friendly way. The fully automatic process has a cycle time of about 40-60 minutes. 


Contact: Ecodas, 28, rue Sebastopol, Roubaix 59100, France. Tel:+33 (03) 2070 9865; Fax: +33 (03) 2024 2381.


Website: www.ecodas.com 

Biomedical waste treatment

Canada-based Infectrol Inc. offers technology to dispose biomedical wastes. The systems are based on Brookes gasification process (BGP). Waste boxes or bags are placed on a loader and this batch is loaded into the primary chamber. The main door is then sealed shut until the vaporization process is complete. No direct flame or forced air is introduced at any time. Heat is transferred into the waste mass through the hearth, which acts as the ceiling of the afterburner. Waste mass is vaporized by intense heat and the fumes are directed to a mixing zone, where secondary air is added and a burner system provides energy. This gaseous mix is highly combustible.


An energy loop is formed whereby energy generated in the afterburning chamber is fed back into the waste mass to help continue volatization. Waste mass and ash reach a temperature of about 1,000C towards the end of the cycle, leaving behind a sterile, inert ash. 


Contact: Infectrol Inc., P. O. Box 15501, No. 265, Port Union Road, Scarborough, Ontario M1C 4Z7, Canada. Tel: +1 (905) 7646 824; Fax: +1 (905) 7646 352.


Website: www.infectrol.com 

New medical/clinical waste disposal unit

Waste Technology New Zealand Ltd. offers two systems to ensure safe disposal of medical wastes. Whirlstream Waste-to-Energy system, complete with emission control, is an ideal incineration system for a wide variety of materials and non-segregated clinical waste. This unit comprises a three-chambered fixed-hearth controlled air incinerator. The design of the third chamber or afterburning chamber is important in that it is designed to run at temperatures in excess of 1,100C, while retaining all off-gases in the chamber for a minimum of two seconds in the presence of at least 6 per cent excess oxygen. This operating schedule is suitable for thermal oxidation of the most temperature-resistant organic compounds and reducing the formation of combustion related dioxins. The Waste-to-Energy unit is available in three different configurations, namely:
  • An incinerator equipped with a dry only emission control system;
  • Stand-alone, without emission control; and
  • Incinerator with dry/wet emission control system.

The Whirlstream heat disinfection system disinfects waste by heating it indirectly to high temperatures and holding at that temperature for about 40 min. The heat, retention time and turbulent mixing during this period ensures greater than 6 log10 reduction in microbial activity. This unit provides a very economical disposal solution for generators of segregated wastes and offers substantial benefits over conventional non-burn processes like autoclaving. The system is almost entirely fabricated utilizing stainless steel. 


Contact: Waste Technology New Zealand Limited, P.O. Box 33472, Takapuna, Auckland, New Zealand. Tel: +64 (9) 5251 323; Fax: +64 (9) 5253 501


E-mail: enquiries@whirlstream.com 


Website: www.whirlstream.com 

Cell and tissue pretreatment process

BioGenex Laboratories, the United States, has obtained a patent from the Patent and Trademark Office for its new procedure for deparaffinizing formalin-fixed, paraffin-embedded tissue sections. This is the fourth patent awarded to BioGenex on the general subject commonly referred to as pre-analytical treatment of cells and tissues, involving tasks such as cell and tissue sample preparation, antigen retrieval, epitope retrieval, cell conditioning, etc.


The BioGenex DeWax process is a one-step dewaxing and rehydration solution that can easily and rapidly remove paraffin from the tissue, that is mounted on to a slide, and rehydrates the tissue section in less than seven minutes. This method has no adverse effect on the quality of the tissue sections prepared for molecular analysis. It does not use any toxic or hazardous solutions, which cannot be said for commonly used processes that generate large quantities of hazardous wastes. In addition, DeWax process could be combined with antigen and nucleic acid retrieval. This dramatically reduces the total turnaround time for such a procedure. Furthermore, the combined process could be easily automated, thereby reducing hands-on time and cost, while improving overall performance. 


Contact: Mr. Philipp Novales-Li, Director, Corporate Affairs, BioGenex Laboratories, United States of America. Tel: +1 (925) 8662 579


E-mail: philippn@biogenex.com  


Website: www.marketwire.com

ELECTRONIC WASTES

Process to recover valuable metals

Materials Processing Corp. (MPC), the United States, uses a sampling and assaying process for recovering precious metal fractions from waste electronics. The process includes manual inspection, shredding, continuous sampling and fire assay. The key process that MPC conducts is to accumulate and fire assay all of the material that contains precious metals. Fire assay is a term used to describe the method of determining the quantities as well as purity of the precious metals.


Electronic items like circuit boards are examined to recover remarketable parts, e.g. IC chips, and isolate hazardous constituents and non-refinable material. Next, the boards are shredded and sent to a smelter. During the smelting procedure, a continuous sample of the shredded circuit cards is taken. The sample then undergoes controlled sintering to create an ash, which is ballmilled for pulverizing and exposing encapsulated surfaces of the ash. The ash is then mechanically screened and separated into three size fractions. Each of these are fire assayed to determine the quantity of precious metals present. Lab fire assays of the three size fractions are used to calculate the quantity of silver, gold, palladium and platinum within the original shredded material. 


Contact: Materials Processing Corp., 2805, West Service Road, Eagan, MN 55121, United States of America.


Website: www.materialsprocessing.com 

Recycling used TVs

Matsushita Environment Air-conditioning Eng. Co. Ltd., Japan, offers technology for recycling television sets. The new method can be classified into the disassembly process, which runs from cabinet removal to picture tube separation, and culletizing process, wherein the picture tubes are crushed into cullet. Key features of the process include:
  • Elimination of physical workload: TV input to CRT removal converting to light manual work and band removal to brushing automated;
  • Multi-model flexibility: 14-32 inch models can be accommodated for integrated processing from disassembly to culletizing;
  • Pursuit of economical justification: Better economy than a manual disassembly operation, increased value creation, high productivity because of the use of a continuous line and two-shift operation; and
  • Increased recycling rate: Collection of high-value items by sorting disassembled components and efficient collection of picture tubes.

Contact: Matsushita Environment Air-conditioning Eng. Co. Limited, 3-28-33, Tarumi-cho, Suita, Osaka 564 0062, Japan. Tel/Fax: +81 (6) 6338 1831 / 6338 1491 


Website: www.panasonic.co.jp ; www.nett21.gec.jp 

Processing electronic scrap

In Germany, Electrocycling GmbH recycles discarded electronics by manually disassembling the waste to remove pollutants like batteries, capacitors, mercury switches, etc. from the sub-assemblies. The sub-assemblies are processed mechanically, which involves crushing and grounding through numerous stages till even the smallest plastic-metal composites have been segregated and sorted. The material is sorted into various metals and a residual material fraction that primarily comprises mixed plastics employing a magnetic and eddy current separator, and air separation technique. 


Contact: Electrocycling GmbH, Landstrasse 91, 38644 Goslar, Germany. Tel: +49 (5321) 3367-0; Fax: +49 (5321) 3367-11


E-mail: info@electrocycling.de  


Website: www.electrocycling.de 

Recycling household and office electric appliances

Mitsubishi Electric Corp., Japan, has developed a recycling facility that disassembles and processes home appliances as well as devices used in offices, e.g. photocopiers, in compliance with the nations recycling laws. The plant can process 8 t/h of waste, with a refrigerator processing capability of 60 units/h and 500 kg/h of urethane. Key features of the system include:
  • Advanced disassembly and sorting (High Efficient Applicable Recycle Technology or Heart) system: Grounding, grading and magnetic/wind/static electricity sorting technologies are combined to recover materials like metals and plastic, and realize a high recycling rate;
  • In addition to recovering and processing the refrigerant Freon from fridges and air-conditioners, harmful matters such as insulation Freon and cyclopentane are appropriately collected from refrigerators and processed; and
  • Information processing system: Compatible with matters related to home appliance manifestos and remanufacturing rates, and compatible with processing feeds, etc., for home appliance recycling network systems.

Contact: Mitsubishi Electric Corp., 2-3, Marunouchi, 2-chome, Chiyoda-ku, Tokyo 100 8310, Japan. Tel: +81 (3) 3218 2111; Fax: +81 (3) 3218 2741

Website: www.melco.co.jp ; www.nett21.gec.jp 

SOLVENTS

Solvent recovery from flue gas

Kurimoto Ltd., Japan, has developed a fixed-bed type flue gas treatment system to recover organic solvents present in flue gas streams. Solvent gases are adsorbed by granulated active carbon and clean air is vented. The adsorbed solvent is recovered by blowing vapour into the active carbon layer, condensed and separated. A few notable features of the Kurimoto system are:
  • Provides a high degree of elimination efficiency;
  • Allows for large changes in inlet concentration;
  • Trouble-free operation;
  • Enables treatment on small- and large-scale; and
  • Lower running costs than comparable solvent recovery systems.
The recovery system is available in three models Model SA (single tower, automatic control), Model DA (twin towers, automatic control) and Model 2BDA (a pair of blowers and towers, automatic control). 


Contact: Kurimoto Ltd., 12-19, Kitahorie 1-chome, Nishi-ku, Osaka 550 8580, Japan. Tel: +81 (6) 6538 7731; Fax: +81 (6) 6538 7756


E-mail: info@kurimoto.co.jp  


Website: www.kurimoto.co.jp 

Vacuum systems for solvent recovery

Laco Technologies Inc., the United States, is offering industrial vacuum systems based on liquid ring vacuum pumps, for recovering all types of solvents. Acetone recovery units, 4.5 kg/h (manual) and 45 kg/h (automatic), are designed for extruders of explosive materials. Key features of the solvent recovery units include:
  • Turn-key system;
  • Manual or PLC-controlled;
  • Explosion-proof design; and
  • Custom design.

Contact: Laco Technologies Inc., 139 West 2260 South, Salt Lake City, Utah 84115, United States of America. Tel: +1 (801) 4861 004; Fax: +1 (801) 4861 007


E-mail: info@lacotech.com 


Website: www.lacotech.com 

Aromatics recovery process

GTC Technology Inc. of the United States offers an aromatics recovery process based on extractive distillation column (EDC) to remove benzene, toluene and xylenes from refinery or petrochemical aromatic streams such as catalytic reformate or pyrolysis fuel. This procedure is superior to traditional liquid-liquid extraction or other extractive distillation in terms of lower capital and operating costs, simplicity of operation, feedstock range and solvent performance. Flexible design permits the technology to be used for grassroots aromatics recovery units, de-bottlenecking or expansion of conventional extraction systems. The technology could also be used to de-aromatize naphthas for high-purity solvents production or for upgrading motor fuel streams.


In GT-BTX process, hydrocarbon feed is preheated with hot circulating solvent and fed at a midpoint into the EDC. Lean solvent is fed at an upper point to selectively extract the aromatics into the column bottoms in a vapour/liquid distillation operation. Non-aromatic hydrocarbons exit the top of the column and pass through a condenser. A portion of the overhead stream is returned to the top of the column as reflux to wash out any entrained solvent. The balance of the overhead stream is the raffinate product, which does not require further treatment.


Rich solvent from the bottom of the EDC is routed to the solvent recovery column (SRC), where aromatics are stripped overhead. Stripping steam from the closed-loop water circuit enables hydrocarbon stripping. The SRC is operated under vacuum to reduce the boiling point at the base of the column. Lean solvent from the bottom of the SRC is sent through heat exchangers before returning to the EDC. A small portion of the lean circulating solvent is processed in a solvent regeneration step to remove heavy decomposition products, that are purged on a daily basis. The SRC overhead mixed aromatics product is routed to the purification section where it is fractionated to produce chemical-grade benzene, xylenes and toluene. 


Contact: GTC Technology Inc., United States of America. Tel: +1 (281) 5974 800; Fax: +1 (281) 5970 942.


Website: www.gtchouston.com 

Solvent recovery apparatus

In Japan, Toyobo Co. Limited, has developed a unique activated carbon fibre (K-Filter) that offers superior performance, compared with traditional activated carbon, as an adsorptive material. The company has also used K-Filter in solvent recovery apparatus, appreciated in numerous industrial sectors as eco-friendly and saving resources. Salient features of the apparatus include:
  • High adsorbing efficiency;
  • Lightweight and compact;
  • Automatic operation;
  • The solvent recovered is of better quality; and
  • Many kinds of organic solvents can be recovered.

In case of application to high boiling point substances, such as silicon oil and mineral oil, and polymerizable monomers like styrene and MMA, this equipment can be used for long periods since the excellent absorption ability is retained for a long time. 


Contact: Toyobo Co. Ltd., AC Operations Dept., 2-8, Dojima Hama 2 Chome, Kita-ku, Osaka 530 8230, Japan. Tel: +81 (6) 6348 3370; Fax: +81 (6) 6348 3418.


Website: www.toyobo.co.jp 

Activated carbon systems to recover solvents

Waterlink/Barnebey Sutcliffe of the United States offers site-installed and skid-mounted units to reclaim around 99.9 per cent of industrial solvents. In the activated carbon unit, process air is routed through one or more carbon adsorbers for solvent extraction. When an adsorber gets saturated, it is replaced with another unit, and the saturated system is regenerated with steam. The separated solvent is condensed into a liquid mixture and then purified for reuse by decantation, distillation or liquid phase carbon adsorption. Inert hot gas regeneration is also available for recovery of water-miscible solvents, thus minimizing additional separation requirements.


A range of materials of construction and system options are available to handle virtually any solvent type and process parameter. The systems abilities range from pre-assembled package facilities for airflows up to 4,000 scfm to engineered turnkey systems with capacities exceeding 300,000 scfm. The larger systems typically include design, procurement, on-site installation, start-up and operator training. Existing installations can undergo upgrading to conform with new emission rules. Some of the industries where the system can be employed are packaging, publishing, gravure printing, pharmaceuticals, chemicals, rubber products, magnetic media, paints and adhesives, photographic items, etc. 


Contact: Waterlink/Barnebey Sutcliffe, 835 N. Cassady Ave., Columbus, Ohio 43219, United States of America. Tel: +1 (614) 2589 501; Fax: +1 (614) 2583 464


E-mail: activatedcarbon@waterlink.com 


Website: www.waterlink.com 

New equipment for solvent recovery

Koch Modular Process Systems (KMPS) LLC of the United States specializes in the design and construction of complete modular process systems for solvent recovery applications. A typical solvent recovery system is designed to operate in a semi-continuous mode to recover isopropyl alcohol (IPA), around its azeotropic concentration, from an aqueous process stream generated while producing a pharmaceutical. The unit is subsequently operated in a continuous mode to dry the IPA, using azeotropic distillation.


KMPS caters to the requirements of pharmaceutical, petrochemical, speciality chemical, biotech, food, flavour and fragrance, and plastics and resins industries for applications such as binary and multi-component separations, high vacuum distillation, solvent purification systems, product purification, solvent drying, etc. 


Contact: Koch Modular Process Systems LLC, 45, Eisenhower Dr., Paramus, NJ 07652, United States of America. Tel: +1 (201) 3682 929; Fax: +1 (201) 3688 989


E-mail: systems@modular-process.com 


Website: www.modular-process.com 

Recovering carboxylic acids

At the Lawrence Berkeley National Laboratory in the United States, a team of researchers have developed new technology for recovering carboxylic acids from solution in organic solvents. This approach is easy to execute and requires less energy than conventional recovery methods. It is especially well-suited for low- to moderate-solubility carboxylic acids such as adipic, succinic and fumaric acids. This breakthrough enhances the recovery of carboxylic acids from aqueous solutions like fermentation broths. Salient features of the cost-effective method include:
  • Removes co-extracted water by stripping;
  • Lessens the solubilities of carboxylic acids, allowing precipitation and recovery of a major portion of the dissolved acid;
  • Successful with commonly used solvents such as ketones, esters, alcohols and ethers; and
  • Effectively removes and recovers carboxylic acids from effluents.

Caboxylic acids can be used in a variety of commercial applications, including as builders in detergents, acidulents and buffers in food, raw material for manufacturing nylon and biodegradable plastics and chemical intermediates for the pharmaceutical industry. 


Contact: Technology Transfer Dept., E.O. Lawrence Berkeley National Laboratory, MS 90-1070, Berkeley, CA 94720, United States of America. Tel/Fax: +1 (510) 4866 467/457


E-mail: TTD@lbl.gov 


Website: www.lbl.gov 

Automated solvent recovery units

Tech Systems Limited, the United Kingdom, offers CR series of solvent recovery units. These specially developed, completely automatic range of vacuum-assisted distillation units are capable of continuous and virtually unattended operation.


For automated filling, level switches monitor the solvent level inside the machine, controlling valves on the solvent inlet, allowing the vacuum to draw in solvent, and maintain the working level during distillation. The unit normally operates for several hours without draining. Then the PLC controls stop the automatic filling and switch the unit into a concentration cycle. It will continue to recover solvent from the chamber but without topping up the level, until the residual sludge is very thick. At the end of this period, the unit will go into drain sequence and then automatically refill. Recovery starts within a few minutes all without operator intervention. An optic fibre sensor monitors the vapour cleanliness and ensures quality of the solvent.


The highly polished surface of the cylindrical distillation chamber is swept clean by self-adjusting brass scraper blades, maximizing the heat transfer efficiency. At the end of the cycle, the drain valve is opened and the blades automatically discharge
the residue. Next, the valve is closed and the chamber refilled with solvent. Process time lost while draining and refilling is minimal. High efficiency of 
heat transfer allows the recovery unit to handle heavily contaminated solvents such as waste products, which would not normally be recoverable.


The flexibility of the PLC controls allows the highest levels of safety interlocks to be used. These include heater temperature and over temperature, residue temperature, condensate temperature, water flow, vapour temperature and degree of vacuum. Optionals supplied are an extraction fan with duct around the drain valve (with an interlock gate), and an interlock to prevent draining unless there is a container present underneath the drain valve. When processing temperature-sensitive substances, automatic injection of a plasticizer can be included, along with nitrogen purging the drain sequence.


Contact: Tech Systems, Road Heath, Tarporley, Cheshire CW6 0EF, the United Kingdom. Tel: +44 (01829) 732 273; Fax: +44 (01829) 730 075


E-mail: tony.g-tech@talk21.com 


Website: www.g-techsystems.co.uk 

Automatic solvent recycling

PBR Industries, the United States, has expanded its line of Resolv-R2 air-cooled solvent recyclers. Resolv-R2 ECO, the latest addition, features a fully automatic cycle and a display for vapour-temperature read-out. It comprises two separate units. The first is a primary evaporation tank, which is connected by rotating joints to a second unit, where diathermic oil is heated and the solvent is condensed. An external valve located at the bottom of the tank facilitates easy removal of wastes. At the end of a cycle, a circulation pump sucks heated diathermic oil out of the main tank back into the secondary unit for cool-down and fast residue removal.


The ECO systems may be equipped with either air-cooled or water-cooled condensers, and are available in a variety of capacities. Additionally, they can be integrated with electric or pneumatic vacuum units to recover high boiling solvents. 


Contact: PBR Industries, 143, Cortland St., Lindenhurst, New York, NY 11757, United States of America. Tel: +1 (631) 2262 930; Fax: +1 (631) 2263 125


E-mail: mnrobbi@attglobal.net


Website: www.pbrind.comwww.screenweb.com 

Vacuum systems and solvent recovery

Rosenmund Limited of the United Kingdom offers a pre-engineered unit that combines vacuum generation and solvent recovery through condensation in a closed circuit system. Apovac system integrates a liquid ring vacuum pump and subsequent cooler. Ideal for vacuum filtration and drying, this advanced unit enables superior performance in a variety of wet chemical processes, including vacuum distillation, crystallization, evaporation, mixing and reactions wherein single as well as multiple solvents are used. 


Contact: Rosenmund (UK) Limited, Tollgate Drive, Tollgate Industrial Estate, GB Stafford ST16 3HS, United Kingdom. Tel: +44 (1785) 609 709; Fax: +44 (1785) 609 701


E-mail: rosenmund_uk@dial.pipex.com 


Website: www.rosenmund.com

AIR POLLUTION CONTROL

Taking the stink out of sewage

A team of researchers at Nanyang Technological Universitys Institute of Environmental Science and Engineering, Singapore, has come up with a new technique to eliminate the bad odour of sewage. The noxious fumes are burned using hydrogen-fuelled flames. This method is more faster than conventional ones and costs just half as much. Other new processes developed to decompose odours include using microbes to eat harmful and malodorous gases.


Website: www.iol.co.za 

Fume filtration

Powertech Pollution Controls Pvt. Ltd., India, offers a fume filtration system to capture and filter fumes, smoke and dust. The Fumekiller is a high-efficiency, two-stage electrostatic precipitator with built-in fan blower. Fumes and oil mist enter the electrostatic filter through a suction hood. After large particles have been removed by the prefilter, the remaining particles enter the electrostatic module, between a series of parallel aluminium plates, where they receive a high positive charge. The particles then pass through another series of plates charged negatively. Here, the positively charged particles adhere to the aluminium plates, even after the electrostatic filter is switched off. Air free from particulate matter exits the system.
Fumekiller comes in three versions, with suction capacities of 500 m3/h, 1,000 m3/h and 2,000 m3/h. Key features and benefits include:
  • Safer and healthier working environment, as hazardous fumes and airborne contaminants are removed;
  • High filter efficiency;
  • Clean environment where housekeeping and maintenance costs are reduced because the particles are captured before they settle down;
  • Eliminates the need for replacing the electrostatic module; and
  • Highly reliable, minimal operating costs and easy to maintain.

Modular filter modules based on electrostatic filtration are available for processing large volumes of air streams to control fine particulates in clean room areas or where pollutants are to be removed. The required number of modules are placed in a mild steel (MS) painted enclosure. The air inlet side is placed in the air stream using a suitable adaptor ducting. The power pack supplying electrostatic voltages to the modules is mounted separately in a control panel near the MS enclosure, with electrical connections made through conduits. Prefilters and after-filters are placed before and after the fine filters. Model FF500 can handle air flow rates of 500-600 m3/h, FF2000 has a capacity to treat 2,000-2,500 m3/h and FF4000 can filter 4,000-5,000 m3/h. Some applications of these filters include:

  • For custom-built applications and can be added module by module to suit various air flow rates;
  • Can be utilized as a centralized system for removal of fumes, smoke, oil mist, coolant mist, dust and fine powders from many in-plant industrial processes generating pollutants that render the shop floor unhealthy.
  • Employed as prefilters for higher class levels, they can increase the life of the main filters and also reduce the total pressure drop as compared with conventional prefilters; and
  • Used as primary filters for Class 100,000 clean rooms and as prefilters for higher class levels of clean rooms.

Contact: Mr. Philip Thomas, Powertech Pollution Controls Pvt. Limited, 1133-1134, 1st Floor, 1st Main, Yeshwanthpur, Bangalore 560 022, India. Tel: +91 (080) 2347 0250/2337 5376; Fax: +91 (080) 2337 4825

E-mail: philipthomas@powertechindia.com 


Website: www.powertechindia.com 

Desulphurization systems for flue gas

Alstom Power Environmental Control Systems offers two technologies for dry flue gas desulphurization spray drier absorber (SDA) and flash drier absorber (FDA). In the SDA process, flue gas exiting the boiler air preheater enters the top of the spray drier into gas distributors where it is routed to rotating disc atomizers. These atomizers use the centrifugal force of a high-speed rotating disc to atomize the reagent slurry. They spray the reagent slurry solution (lime) into flue gas to react with sulphur dioxide (SO2). Reaction with alkali absorbent forms dry reaction products. At the same time, droplets generated by the atomizers are dried by the heat of the flue gas. Process controls are designed to maintain the scrubber temperature and SO2 removal rate, and minimize reagent usage. Flue gas, which contains the dried reaction products, then enters a fabric filter or electrostatic precipitator. 
Key benefits of the SDA method are:
  • Low power consumption;
  • Multiple atomizer design;
  • Over 95 per cent collection of acid gases and most trace metals;
  • Low initial capital costs as well as operating costs;
  • Increased availability and operational reliability;
  • Dry waste products generated for ease of disposal;
  • On-line spare atomizers facilitate easy maintenance;
  • Improved process control;
  • No need for exotic materials or linings; and
  • No flue gas reheating needed, thus offering improved thermal operating efficiency.

The FDA system uses dry reagents suspended in the flue gas stream to absorb SO2. Optionally, the reagent could be circulated from the dust collector to the reactor and in some cases water may be added for gas cooling. The FDA provides a compact, simple solution to acid gas absorption requirements.


Website: www.specialized-mechanical.com 

Nanotechnology for better air

A nanometre photocatalyst-based detoxification purifier has been developed in China to effectively dissolve organic pollutant gases like formaldehyde, benzene, toluene and dimethyl benzene. The purifier was devised jointly by Hefei Municipal Diseases Prevention and Control Centre, and the Chinese University of Science and Technology. Intended to function as a detoxification agent, disinfectant, bacteria suppressant and air purifier, the new device can eliminate indoor hazardous gases emitted by interior decorations.


Prototype units incorporating this system have passed verification checks. A detoxification purifier for central air-conditioning systems is being produced, and one for hospital and sedan car applications is under development.


Website: www.most.gov.cn 

New ESP

Terng Woei Industry Co. Limited of Taiwan is offering an electrostatic precipitator (ESP) that can capture particles as small as 0.01 m. This unit does not strain dirt from the air but attracts and holds it just like a magnet. Though contaminated air has long been recognized as being detrimental to human health and the environment, the extent to which it is harmful is not known yet. However, ever-increasing studies strongly point to polluted air as a contributing factor to many illnesses, particularly diseases of the respiratory and circulatory system.


Website: www.allproducts.com 

Novel diesel emission control technology

Extengine Transport System LLC, the United States, has developed a new low-cost technology to control emission from diesel fuelled vehicles. Advanced Diesel Emission Control (ADEC) system has been shown to be capable of reducing over 90 per cent of NOx emissions and 95 per cent of particulate matter, both are toxic visible and invisible diesel exhaust emissions. ADEC is based on selective catalytic reduction (SCR). The unit designed for vehicle applications diffuses minute quantities of a reductant into the exhaust stream after combustion has occurred; the small refill tanks are swapped out periodically as needed.


Santa Clara Valley Transit Authority chose the ADEC system over other retrofit technologies for a demonstration programme partially due its low cost and successful implementation on City of Houston vehicles. 


Contact: Mr. Phillip Roberts, Extengine Transport System LLC, the United States. Tel: +1 (714) 7743 569


E-mail: proberts@extengine.com

Flue gas scrubber

Ehox Tuote Oy, Finland, offers flue gas scrubbers specifically designed to treat flue gas streams from biomass-fired district heating facilities. This system effectively combines pollution control and energy conservation. It removes sulphur-containing compounds, chlorides, particulates and other impurities. Ehox scrubber provides excellent heat recovery, producing clean warm water with a typical temperature of 66C for process applications like bleaching. Also, energy consumption is considerably lower than that of other designs.


To rule out corrosion problems, the scrubber is constructed mainly using glass reinforced plastic. This offers maximum flexibility of application and the scrubber can be operated at any practical pH value. For less severe applications, stainless steel can be used. 


Contact: Ehox Tuote Oy, Lavamaentie 275, Vahto 21310, Finland. Tel: +358 (02) 2579 415; Fax: +358 (02) 2579 414


E-mail: ehox@ehox.fi 


Website: www.ehox.fi

PUBLICATIONS

International Resource Guide to Hazardous Chemicals

This book includes more than 7,500 entries highlighting chemical producers worldwide. It is a complete source of contact information for manufacturers, agencies, organizations and useful source of information regarding hazardous chemicals.

Plastic Waste: Feedstock Recycling, Chemical Recycling and Incineration

This publication introduces the different waste management options, with emphasis on technologies that are already being employed or assessed for use on a commercial scale. It discusses in detail the methods for treating mixed plastic wastes and PVC-rich wastes. Comparisons are made between the different types of recycling presently available in terms of life cycle assessment and environmental impact.


For the above publications, contact: Chemtec Publishing, 38, Earswick Drive, Toronto-Scarborough, Ontario M1E 1C6, Canada. Tel: +1 (416) 2652 603; Fax: +1 (416) 2651 399


E-mail: info@chemtec.org 

Catalytic Air Pollution Control: Commercial Technology

This second edition is an expanded and updated version of the original four parts. New chapters have been added while retaining the practical description of the catalysts and processes. The first five chapters describe the fundamentals of catalysis and catalysts. Two chapters deal with the chemical and physical properties of monoliths, the support of choice for environmental applications. Also included are sections on fuel cells/fuel processing and novel approaches for purifying ambient air. Current technologies to control emissions from mobile and stationary sources have been discussed. Emerging technologies covered include:
  • Catalytic challenges for five different fuel cell technologies as well as hydrogen generation for fuel cell applications; and
  • Ambient air clean-up from mobile and stationary sources.

Contact: John Wiley and Sons Canada Limited, 22, Worcester Rd., Etobicoke, Ontario M9W 1L1, Canada. Tel: +1 (416) 2364 433; Fax: +1 (416) 2368 743; 


E-mail: canada@wiley.com


ASIAN AND PACIFIC CENTRE FOR TRANSFER OF TECHNOLOGY

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