VATIS Update Waste Management . Nov-Dec 2004

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Waste Management Nov-Dec 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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Air pollution in Indonesia estimated at US$400 million

An Asian Development Bank (ADB) report has pegged the annual cost of air pollution in Indonesia at US$ 400 million. This figure is predicted to increase tenfold by 2010 unless measures are initiated to improve the environment. Announcing a grant worth US$700,000 to help enhance air quality in two Indonesian cities, ADB stated that urgent steps are essential to reduce hazardous urban pollution levels, which are among the worlds worst. A combination of rapid urbanization and weak controls have made air pollution a significant urban threat, more so for the poor, resulting in loss of productivity.

From among the five major urban centres Semarang, Yogyakarta, Jakarta, Bandung and Surabaya ADB will select two cities to take part in a Japanese-funded project aimed at improving pollution control frameworks. According to UNEP, Jakarta is one of the worlds most polluted cities where airborne levels of lead, nitrogen dioxide (NO2) and particulates are significantly higher than those specified by the World Health Organization (WHO). ADB has provided technical assistance to the government for decreasing vehicular emissions.


Global leader in computers sets recycling target

The multinational company Hewlett Packard (HP) has accelerated its product recycling programme by setting a global target of 0.45 billion kilograms of electronic wastes by 2007. This goal is exclusive of the millions of products that HP and its partners refurbish, reuse, donate or resell. Last year, HP recycled over 45.35 million kilograms of electronic products and printing equipment, through its Planet Partners return and recycling programme, raising the company-wide total to 226.75 million kilograms since it started recycling in 1987. One of HPs three global citizenship priorities include addressing electronic wastes. The other two focus on raising social and environmental levels in the supply chain and extending the access to information technology.

HP intends to achieve its goal by expanding the programme to more customers and creating new ways for consumers to return and recycle used or unwanted electronic equipment in a convenient and environmentally responsible manner. Since HP Planet Partners launch in 1991, various initiatives designed to raise awareness of the importance of recycling waste computer products have been implemented, including:
  • E-coupons: offer on-line recycling customers savings on new products ordered from;
  • Labels and envelopes: Postage-paid labels/envelopes are included in many replacement HP LaserJet and inkjet print cartridge boxes sold in the United States and Europe;
  • Standards: HP has global recycling standards for management of end-of-life computer hardware products, which address labour and safety at supplier operations; and
  • Public policy: Working along with state, provincial and national governments, HP has developed shared responsibility recycling legislation where producers bear the onus of recycling their products.

The HP Planet Partners programme operates globally in over 30 nations and is striving to lower the environmental footprint of IT products, minimize wastes going to landfills and provide customers with a convenient and environmentally sound end-of-life solution.


Green solution for electronic wastes

As of next year, manufacturers of electronic goods in Europe will be required to take back and partially recycle old equipment. From 2006, electronic products must be totally lead-free. An industry workshop was organized in Germany to shed light on the means that companies could adopt to fulfil the new requirements. Representatives from several leading companies took part in the worlds largest international conference devoted to environmental protection in the electronics industry, Electronic goes Green 2004, and presented updates on the utilization of lead-free soldering as well as strategies for ecological and economically viable management of electronic waste.

A team from the Fraunhofer Institute for Reliability and Microintegration IZM,Germany, unveiled the development of lead-free systems and test results relevant to their reliability and environmental impact. The systems include conventional interconnection technologies like surface mounted devices (SMD) and state-of-the-art technologies, including wafer level bumping and flip chip packaging. An economical alternative to conventional recycling approaches is reusing the entire components in new products, to satisfy the demand for spare parts.


Pan-Asian recycling system mooted

Japans Ministry of Economy, Trade and Industry (METI) has compiled a programme, which foresees a pan-Asian recycling system that allows for easy movement of waste material across international boundaries. The proposal envisions establishment of recycling-based societies in individual Asian nations as the first step.

To aid progress at this stage, a subcommittee of the Industrial Structure Council (an advisory panel to METI) is expected to recommend that the government promote transfer of recycling technologies to developing countries as well as exchange of people between other Asian nations and Japan. It is also likely that the subcommittee will recommend extension of loans through government-affiliated financial institutions to provide necessary funding. As the next step, creation of a pan-Asian recycling system that enables resources to be circulated efficiently throughout Asia will be proposed.


Chinas first e-waste recycling centre takes shape

Loyalty Enterprises Group will set up Chinas first recycling centre for discarded TVs and PCs in Qingpu district of Shanghai. With a capacity to process up to 500,000 TVs and PCs a year, the US$2 million facility will cover 15,000 m2. It is expected to commence operation at the end of next year. Metals, glass and other materials extracted at the facility will either be recycled further or sold directly to other companies. Initially, the company will work with local as well as foreign companies to supply material, besides operating closely with local universities. The company expects to establish in Shanghai a network of recycling facilities, which will be the collection points for the facility.


Sewage disposal gets better in China

Over the last couple of years, sewage disposal in China has dramatically improved to reach 42 per cent. The government is investing on environmental infrastructure to address the problem of sewage treatment. While some cities have adopted sewage disposal fees, others are constructing additional treatment facilities. Meanwhile, it is estimated that newly built sewage disposal facilities in the previous three years are equal in construction scale to those built in the previous five decades.

Website: www.

Polluting companies denied access to Chinese stock market

In China, environment officials have cautioned that if any company fails to comply with pollution reduction deadlines, they will be banned from raising stock market capital for three years. About 28 companies, mostly energy and chemical companies, have been shortlisted as per their sulphur and dust emission targets. A spokesperson for the Pollutant Control Office has stated that the blacklisted companies will shell out US$215 million for new pollution control measures.


China debates e-waste legislation

New Chinese legislation to govern the disposal of electronic wastes has been delayed for long by disagreements between the manufacturers, government agencies and consumer groups. Even though the procedure for legislating the management of electronic garbage was initiated over three years ago, a draft of the law has not yet been finalized. The main bone of contention is how to split the bill for disposing the waste. The five product sectors likely to be most affected are computers, TVs, washing machines, refrigerators and air-conditioning systems.

Mr. Zhang Youliang, Assistant Chief Engineer, China Home Electronic Appliance Research Institute, has stated that The legislation aims to make manufacturers the one chiefly responsible for handling the recycling of discarded electronic goods. However, manufacturers are reluctant as this added responsibility will greatly raise their costs. Drafting of the legislation has been designated as one of the most important and urgent tasks for Chinas National Development and Reform Commission to focus on during 2004.


India imposes ban on scrap imports from war zones

India is readying to ban imports of scrap metal from any country falling in or adjoining war zones worldwide. This initiative follows the detection of live rockets and shells in a scrap iron consignment imported from Iran. Indian security officials were baffled by the mounting stockpile of deadly explosives unearthed in the vicinity of Ghaziabad, after a rocket hidden in the steel scrap accidentally went off killing 10 people. Dozens of live shells have also cropped up in neighboring districts of Uttar Pradesh, with Army and police personnel still rummaging through consignments. Nearly 31 projectiles have so far been recovered and the search is still on. Manufacturing firms and dealers have been told to exert extreme caution when placing their orders for scrap.


China allocates US$84.3 billion for environment

China has earmarked approximately US$84.3 billion for pollution control and environmental measures for the period 2001-05. This is equal to 1.3 per cent of the nations GDP in the same period. Funds are being used mainly to reduce water and air pollution levels, improve solid waste disposal and construct environment protection facilities. More emphasis has been placed on heavily polluted regions and cities. Environmental protection sector, a major component of the economy, has turned into a rising inter-trade and trans-regional industry after development during the last 20 years. By the end of 2002, people working in this sector had surpassed 3.5 million.


Awareness in India about e-waste disposal

In India, electronic waste (e-waste) is included under List A and List B of Schedule 3 of Hazardous Wastes (Management and Handling) Rules, 1989. Import of these wastes need specific permission from the Ministry of Environment and Forests. As collection and recycling of e-waste are at present undertaken by the informal sector, the government has initiated the following steps to raise awareness with regard to the environmentally sound management of e-waste:
  • A workshop on electronic waste management was organized by the Central Pollution Control Board, or CPCB, in collaboration with Toxics Link, an NGO;
  • CPCB has commenced efforts for the rapid assessment of e-waste produced in major cities;
  • A National Working Group has been set up to formulate a strategy for e-waste management;
  • A comprehensive technical guide on Environmental Management for Information Technology Industry in India has been published and widely circulated by the Dept. of Information Technology (DIT) under the Ministry of Communication and Information Technology;
  • A demonstration project was set up by DIT at the Indian Telephone Industries, Kerala, to recover copper from printed circuit boards; and
  • Many seminars and workshops have been organized in various parts of the country by DIT on Environmental Management.


Sri Lanka stays investment proposals

In Sri Lanka, the Board of Investment (BOI) recently froze post-consumer waste investment proposals pending formulation of regulations by government authorities on the import and/or export of hazardous wastes. The projects from Germany, the United Kingdom, Switzerland and India are for recycling used PET bottles, recycling and/or washing of used clothes, and recycling of electronic wastes. The proposals were subject to close scrutiny at the BOI investment appraisal stage and rejected later because of contamination risks and the perils of excessive disease and environmental pollution caused by such operations.

BOI aims to prevent efforts to make Sri Lanka a dumping ground for any projects that involves post-consumer waste from developed or developing nations, particularly those involving waste plastics, clothes, industrial and/or automobile parts and scrap metal recycling. Other items on the list of industries, as suggested by the Central Environmental Authority, that will not find favour with BOI are post-consumer PVC materials and scrap PVC, electronic or electrical items, batteries, photographic films, tyres and rubber wastes.


Chinas first recycling economic regulation

Guiyang is Chinas first experimental recycling economic eco-city which has received approval from SEPA. The nations first recycling economic regulation issued by the Standing Committee of the NPC of Guiyang came into effect on 1 November. This regulation is expected to boost recycling industries and also assist in establishing a recycling economic eco-city with legal guarantee.

Guiyang will implement a system of recycling industries and construct a recycling economic eco-city with good ecology, reasonable arrangement, and harmonious relationship between humans and nature. Many experimental recycling programmes have been initiated in agriculture, industry and consumption. These include an eco-friendly vegetables and fruits base in Wudang district, a national ecological demonstration base for phosphoric coal industry in Kaiyang county and an ecological industrial source for the recycling commercial coal industry in Qing town. Relevant officials in Guiyang employed educational measures to win public support for advancement of the eco-economy and erection of an eco-city, which raised general awareness regarding sustainable development. Shandong Yanzhou Mining Group would be cooperating with Kaiyang Phosphorus Mining Group and investing in the development and construction of a national ecological demonstration base for the phosphoric coal industry.



Recycling waste agricultural plastics

The Institute of Chemist Technology of CSIC, Italy, has developed a new process to treat agricultural plastic wastes by direct contact catalytic cracking. In the Recaplas process, the use of a low-cost catalyst at high temperatures enables the quality of the products to be determined when desired. Polymeric chains of plastics are degraded into waxes and liquid and gaseous hydrocarbons (HCs). Liquid HCs can be used as feedstock for refineries, engine fuel or raw materials in the petrochemical industry. Waxes could be used to make lubricants, while gaseous HCs serve as an energy source for the same catalytic cracking process endothermal process.

In this process, crude chopping of plastics is followed by washing, fine grinding and a drying process. Next, the material produced is melted and continuously fed, together with the catalyst, into a catalytic reactor. The plastics get converted into reaction products; the main products of the reaction, compressible or non-compressible HCs exit in the gaseous phase and are cooled in a heat exchanger that produces condensation of the main product. A small fraction of waxes escape from the base of the reactor. The procedure includes a continuous catalyst regeneration system. Benefits of the process include:
  • Treats plastics from padding and greenhouses, even though largely degraded, which are practically not treated at present because of lack of economically viable technologies;
  • No gaseous pollutants are released;
  • Tolerates unclean feedstock;
  • Eliminates the need for special localization as the process products are transportable in tanks; and
  • Converts blends of the majority plastics (PE, PS, PP) into municipal solid wastes.

Contact: Ms. Maria Elena Castro Martinez, Italy. Tel: +34 (96) 3622 757



Valuables recovered from auto shredder residues

Salyp N.V., Belgium, has developed a dry mechanical sorting process to extract copper, mixed plastics, PUR foam and other materials from auto shredder residues (ASR). No water is used in this process, except in a secondary stage for washing urethane foam so that it can be reused in carpet backing. The process starts with the separation of ASR particles into three sizes: 0-12 mm (metal and glass), 12-50 mm (fibres and plastics), and larger pieces of foam and plastic. Foam is passed on a conveyor belt through a metal separator and is then sorted from rigid plastics utilizing a mechanical device, which compresses the foam between two rollers that rotate at different speeds. As the foam is released, it springs back and bounces up, allowing it to be blown off the belt. This compression and release loosens dirt in the foam, enhancing the effectiveness of a subsequent wet washing process developed by Argonne National Laboratory in the United States.

The 0-12 mm fraction proceeds past magnets, to separate ferrous metals, into dry gravity separation (DGS), a technique from Fren Erschiessungs-u. Bergbau, Austria, that integrates vibration and air for separation by density. The 12-50 mm part enters Salyps mechanical equipment to separate fibres from rigid plastics. The fibre-rich fraction (still containing some plastic) is ground and passed through a second DGS separator to remove fibres (sold for fuel) from the plastic, which is sieved to remove copper. The plastic-rich flow is shredded and segregated into non-ferrous metals, ferrous metals, a wood-rich fraction and a plastic-rich stream. All the four fractions are recovered.
Product-enriched streams yielded by Salyps procedure have steady markets 3 per cent PUR foam, 10 per cent iron-rich material, 9 per cent copper-rich (including other non-ferrous metals and glass), 44 per cent organic and fibre materials for fuel, 2 per cent wood for fuel and 18 per cent mixed plastics. This is 86 per cent by weight recoverable products plus 14 per cent dust and leftover waste that is landfilled. Website:

Salyp N.V., Belgium, has developed a dry mechanical sorting process to extract copper, mixed plastics, PUR foam and other materials from auto shredder residues (ASR). No water is used in this process, except in a secondary stage for washing urethane foam so that it can be reused in carpet backing. The process starts with the separation of ASR particles into three sizes: 0-12 mm (metal and glass), 12-50 mm (fibres and plastics), and larger pieces of foam and plastic. Foam is passed on a conveyor belt through a metal separator and is then sorted from rigid plastics utilizing a mechanical device, which compresses the foam between two rollers that rotate at different speeds. As the foam is released, it springs back and bounces up, allowing it to be blown off the belt. This compression and release loosens dirt in the foam, enhancing the effectiveness of a subsequent wet washing process developed by Argonne National Laboratory in the United States.

The 0-12 mm fraction proceeds past magnets, to separate ferrous metals, into dry gravity separation (DGS), a technique from Fren Erschiessungs-u. Bergbau, Austria, that integrates vibration and air for separation by density. The 12-50 mm part enters Salyps mechanical equipment to separate fibres from rigid plastics. The fibre-rich fraction (still containing some plastic) is ground and passed through a second DGS separator to remove fibres (sold for fuel) from the plastic, which is sieved to remove copper. The plastic-rich flow is shredded and segregated into non-ferrous metals, ferrous metals, a wood-rich fraction and a plastic-rich stream. All the four fractions are recovered.

Product-enriched streams yielded by Salyps procedure have steady markets 3 per cent PUR foam, 10 per cent iron-rich material, 9 per cent copper-rich (including other non-ferrous metals and glass), 44 per cent organic and fibre materials for fuel, 2 per cent wood for fuel and 18 per cent mixed plastics. This is 86 per cent by weight recoverable products plus 14 per cent dust and leftover waste that is landfilled.


Electricity from plastic wastes

Beijing Roy Environment Technology Co. Ltd. (Royco), China, offers EZ-Power Generator to convert waste plastics into electricity. This new generation of plastic cracking units transforms waste plastics into oil by low-temperature thermal cracking in the absence of air and then uses the output to generate electricity. The system includes a feeding unit, reaction unit, distillation unit, sludge extractor/drying unit, oil storage unit, circulation water unit, wastewater treatment unit, scrubbing unit and power generating system. EZ-Power Generator does not discharge any emissions and works almost noiselessly.

Contact: Dr. Patrick Hayes, Royco, Beijing. China. Tel: +86 (10) 6599 5460.


DuPont technology recycles air intake manifolds

DuPont Engineering Polymers and Toyota Motor Corp. have confirmed the feasibility of using composite recycling technology (CRT) from DuPont for reclaiming and reusing Nylon 6 from automotive air intake manifolds, thereby decreasing the environmental footprint. CRT is a closed-loop nylon recycling process that converts parts made of glass- or mineral-filled Nylon 6 or 66 into resin that is essentially equivalent to virgin. The procedure dissolves used polyamide and then filters away contaminants and fillers. Molecular weight of the recovered polyamide is increased to the level desired for final application.

Contact: DuPont, Chestnut Run Plaza, 705/GS38 Wilmington, DE 19880 0705, the United States. Tel: +1 (302) 7741 000



Finished plastic compounds from shredder wastes

Galloo Plastics, France, recycles auto shredder residues (ASR) into polyolefin and polystyrene pellets. The system integrates a proprietary series of existing techniques, modified for ASR, on which the company holds four patents, with two more pending. However, the wet density separation technology, involving a series of dynamic altered-density media drums to separate the main polymer components in ASR, was obtained from Engineering Separation and Recycling (ESR) Company based in the United States.

Shredder waste contains about 5-20 per cent of recoverable polymer content. Separation begins with a metal reclaiming operation, which grinds the ASR to around 25 mm fragments. These pass on through a large trommel, or rotating cylindrical screen, for classification into a light thermoplastic fraction and heavy thermoset portion. Next, air classification removes textiles and PUR foam. The remaining thermoplastics and thermoset rubber pass through eddy-current separators to separate copper. The remaining plastics are put through a series of four modified ESR dense-media separation drums which contain liquids of different densities. While the first medium separates organics from inorganics, the second segregates PVC from other plastics. The third and fourth media are used to reclaim valuable metals from a fraction comprising engineering plastics such as ABS and nylon.

Galloos process concentrates about 90 per cent of thermoplastics in a portion that is just 10 per cent of the original mass. The pre-concentrate is subjected to a proprietary static dense-media dissociation, that uses large vats, where materials between 0.9 and 1.5 g/cm3 density are separated, with a precision of 0.002 g/cm3. Heavy fractions are removed by augers from the bottom while light fractions are skimmed off the top. PP is isolated from PE and PS while ABS and talc-filled PP are separated from the remaining plastics of 1-1.1 g/cm3, which are landfilled. In the final compounding operation, fast-moving conveyors bring a rainbow of coloured plastic chips to feed three compounding extruding systems continuously, two single-screw and a 100 mm Leistritz twin-screw. For quality control, the compounds are tested for melt flow, tensile strength, flex modulus and impact strength.


Recycling plastics from WEEEs

In the United Kingdom, Sims Group has commissioned new equipment for upgrading approximately 7,700 t/y of plastics obtained from fridges and waste electronic and electrical equipment (WEEE). The company states that 220,000 t/y of WEEE plastics presently being landfilled, following shredding and separation of the metallic portion, will have to be recycled under the requirements of the proposed WEEE Directive.

The new recycling process employs a three-stage system to segregate various types of polymers by taking advantage of their different densities. After granulation of WEEE and removal of metals, mixed plastics are placed into three different chambers holding water of specific densities. In each chamber, certain plastics either float or sink in the water and can then be separated before being tested for quality. The system can process 7.7 t/h of material. Sims Group is now looking to expand its plastics upgrading procedure into difficult plastics, like those found in car bumpers. The next level of technology will allow for refining styrene.



Incineration plants for hospital wastes

Ecoling Partner AG of Switzerland offers incineration plants to dispose of wastes produced at medical treatment facilities. Waste is incinerated in a rotary kiln, which comprises a horizontally arranged cylinder, with a refractory lining interior, rotating around its own axis. Equipped with an auxiliary gas-fired burner at one end, the kiln operates under a slight depression to ensure that any leakage (of atmospheric air) can only be inwards. The high-temperature oxidizing environment within the kiln decomposes wastes into gaseous combustion products and ash. While gaseous fraction is further oxidized in the post-combustion chamber to destroy all organic compounds, ash discharged from the kiln cools in the ash conveyor and is gathered and sealed in a container. The plant has water quenching and venturi system as well as demisters for the treatment of flue gases from the post-combustion chamber.

The plant operating 24 h/day can treat 2,000 kg/h of wastes.

Contact: Ecoling Partner AG, Zurichbergstrasse 20, CH 8028 Zurich, Switzerland. Tel: +41 (1) 2674 360; Fax: +41 (1) 2674 361



New hospital waste disinfection system

Oriam, France, has introduced an environment-friendly hospital waste disinfection system as an alternative to incineration. Dechets Hospital Services (DHS) system provides full service, including inventory, collection, decontamination, sterilization, crushing and grading of waste as well as traceability management. Following evaluation at the hospital, waste is collected and taken to the decontamination facility. Collection is using highly specialized vehicles fitted with on-board weighing units, computer systems for entering tracking data and disinfected and leak-proof containers to substitute filled ones. The containers are labelled with bar codes for identification and tracking, facilitating traceability at all times.

On arrival at the facility, wastes held in the container are transferred, without human intervention, into stainless steel skips which are then loaded into an autoclave for processing. The treatment procedure involves a decontamination phase with alternate steam (159C, 5.5 bar) and vacuum (-0.99 bar) steps, followed by crushing, shredding and grading. Waste is formed into an inert residue that does not require management using expensive incineration procedures.

Contact: Oriam, rue Jean Jaures, Levallois Perret 92300, France. Tel: +33 (11) 3317 098/831


Vertical incinerator

Plantec Inc., Japan, offers patented vertical incinerator system that can be utilized to efficiently dispose of all kinds of wastes. This unit complies with the standards stipulated by the Health and Welfare Ministry, UNEP, WHO and EPA. The new system is extremely slim yet assures stable combustion. It features all the strong points of fixed-bed furnaces, stoker furnaces and fluidized bed furnaces to complement the disadvantages of gasification furnaces and rotary kilns. The incinerator has a simple cylindrical structure with a chamber for recombustion located atop the combustion zone. Its water-cooled wall permits no clinker adhesion.

In the system, waste drops under its own weight without being compressed while it is burnt and thus the quality of waste is kept uniform in the vertical direction, ensuring good ventilation despite thick-layer firing. As the furnace is free from abnormal combustion and variations in internal temperature, combustion is easily controlled and stabilized. Waste is subjected to high temperatures, enabling incineration ash to be burnt completely without any production of dioxins. Medical wastes such as diapers, infectious scraps, plastics and glasses can be incinerated in the Plantec system.

Contact: Plantec Inc., Head Office, 1-6-7, Kyomachibori, Nishi-ku, Osaka 550 0003, Japan. Tel: +81 (6) 6448 2200; Fax: +81 (6) 6448 2250



Thermal destruction of medical waste

In Germany, researchers at Martin-Luther University have tested under different conditions a demonstration plant for the thermal destruction of medical waste utilizing dc plasma torches as the energy source. 3-D CFD modelling of the gaseous phase in the thermal plasma reactor has been undertaken to study the experimentally observed phenomena, with the goal of improving the process with regard to conversion rate and power consumption per unit weight.

The scientists are examining many models for energy release and study- ing additional parameters needed to approach the real process as closely as possible. Results for temperature, velocity, as well as residence time distribution are evaluated and qualitatively compared with images taken from the operating process.

Contact: Mr. J. Fiedler, Department of Engineering Sciences, Martin-Luther University Halle-Wittenberg, Germany.



Liquid medical waste disposal powder

Omni/ajax Inc., the United States, offers a safe and effective method to neutralize and solidify hazardous medical wastes. The Omni-Kap Sharps Solidification kit is based on patented proprietary solidification technology. The kit comprises four plastic containers of special Omni-Kap powder which, when mixed with water, sets rapidly to encapsulate any waste that has been added. Each container makes about 4.456 l of rock-like solid when set.

Omni-Kap surpasses the latest DOT medical waste disposal needs under HM-226, Hazardous Materials: Revision to Standards for Infectious Substances. The dry powder, single pack absorbent/solidifier cementatiously solidifies medical wastes like sharps, needles, broken glass, etc. All the free water is chemically bound and not just gelled as is the case in many competitive products.

Contact: Omni/ajax Inc., 49, Pocono Forest, Gouldsboro, PA 18424, the United States. Tel: +1 (570) 8484 186; Fax: +1 (570) 8484 187



Plasma treatment

In Taiwan, officials with the Environmental Protection Administration (EPA) and Atomic Energy Council (AEC) are promoting a novel high-temperature plasma melting process for treating hazardous wastes. Researchers at AECs Institute of Nuclear Energy Research report to have fully completed pilot testing of the technology. Both AEC and EPA signed a contract that endorsed the project as home-grown technology and environmentally friendly.

AECs process utilizes the intense heat of a plasma torch, at 1,400-1,650C, to degrade toxic organic and inorganic compounds, while reducing volume by up to 80 per cent. The high temperatures break down the molecular bonds of toxic substances and reduces them to simple elemental compounds and gases, while heavy metals are encapsulated in a compacted and dense black matrix that appears like fast-cooled volcanic lava glass. Waste is converted into insoluble, hardened and chemically inert substances, which are suitable for use in construction. Biomedical wastes from hospitals, hazardous wastes from municipal incinerators and industrial sources can be treated by the process.



Recycling scrap liquid crystal displays

In Taiwan, researchers at Da-Yeh University have developed a method to reclaim liquid crystal displays (LCDs), which are increasingly being used to replace cathode ray tube displays. An LCD contains harmful materials like benzene and indium-tin oxide (ITO). The patented technique includes the following steps:
  • Cutting the edge of the LCD
  • Separation of upper and lower ITO glass to get to the liquid crystal
  • Cleaning the liquid crystal by ultrasonics
  • Drying the ITO glass and polarizing filter and
  • Immersing in liquid nitrogen to separate ITO glass from the polarizing filter.

Contact: Mr. Ching-Hwa Lee, Dept. of Environmental Engineering, Da-Yeh University, Changhua, Taiwan. Tel: +886 (4) 8511 337



Giving new life to automotive e-waste

In Germany, researchers from the Technical University Berlin and IZM have developed an automated disassembly and repair line for salvaging old electronic equipment from automobiles. The classic approach to the disposal of such electronic equipment is shredding, recovering copper and precious metals, and incinerating plastics. Re-using entire components in new corresponding products to meet the demand for spare parts is a more economical alternative. With an average life of 12 years on the road for cars, many electronic spare parts needed to run them are often no longer in production. Scrap vehicles are an invaluable reserve for such sought-after spares. Data recorders and malfunction indicators in an electronic device that reveal the events occurred in its life thus far are used to assure quality.

Contact: Dip.-Ing. Harald Ptter, Fraunhofer-Institut fr Zuverlssigkeit und Mikrointegration, Gustav-Meyer-Allee, 13355 Berlin, Germany. Tel: +49 (30) 46403-139



Eliminating EOL electronics

Startech Environmental Corp., the United States, has been awarded a contract by Concurrent Technologies Corp. (CTC) to demonstrate the ability of its Plasma Converter System (PCS) to destroy end-of-life (EOL) electronics irreversibly under CTCs Demanufacturing of Electronic Equipment for Reuse and Recycling (DEER2) programme. The demonstration project will test PCS capability to economically dispose of and convert EOL electronic scrap into a usable synthesis gas and inert melt using a single step process.

PCS is basically an electrochemical system that, while safely destroying wastes (including those listed as hazardous), converts them into useful and valuable commodities. This is achieved efficiently and economically with relatively fewer moving parts and without combustion. In this process, feed materials undergo chemical dissociation, or decomposition, after which their elemental components are reformed into useful commodities.

The companys patented StarCell hydrogen selective membrane unit separates hydrogen from the gas (PCG) produced by the plasma converter. PCG is a clean synthesis fuel gas mixture with good commercial value.

Contact: Website:


Recycling made easy

Onyx Environmental Services, the United States, has introduced a prepaid cost-effective recycling system for disposing of lighting and electronic wastes. Such wastes could be transported to the Electronics Recycling Division of Onyx in secure OnyxPak boxes, pails and fibre drums. The containers are certified by the United Nations and approved for the safe transportation of fluorescent lamps, TSCA-exempt PCB and non-PCB lamp ballast, dry cell batteries, dental amalgam waste, mercury thermostats, CRTs and various computer electronics items. The firm markets OnyxPak to customers directly as well as through distributors.



Eliminating dioxins

Takuma Co. Ltd., Japan, is offering dioxins decomposition equipment based on advanced oxidation (AOX) processes. AOX methods employ ozone (O3), hydrogen peroxide and/or ultraviolet (UV), etc. to produce hydroxyl (OH) radical, a dominant oxidant that destroys and removes trace toxic substances, including dioxins. Moreover, these processes do not create secondary pollution and eliminate the need for treating the condensed effluent streams or treatment and storage of the used adsorbent.
Takuma has introduced UV-Falling Film (UV-FF)/ozone treatment and ozone/hydrogen peroxide (multiple injection) treatment. In a leachate treatment facility, UV-FF/O3 is used for pretreatment while O3/hydrogen peroxide treatment is adopted when it is installed downstream of a sand filtration unit. Potential applications for Takumas technology include leachate treatment at landfill sites, effluent treatment at incineration facilities, and treatment of dioxin-polluted water from ponds, lakes, aquifers, etc.

Contact: Takuma Co. Ltd., 2-33, Kinrakuji-cho, 2-chome, Amagasaki, Hyogo 660 0806, Japan. Tel: +81 (6) 6483 2616; Fax: +81 (6) 6483 2757



Degrading system for dioxins

Kubota Corp., Japan, offers a photochemical method to degrade dioxins. The advanced technique employs ozone and ultraviolet (UV) light to break down one of the most toxic chemicals into carbon dioxide, water and other harmless compounds. UV light converts dissolved ozone into highly reactive hydroxyl radicals. Dioxins are then degraded through a combination of dechlorination by UV and a fission of double bonds by hydroxyl radicals.

The unit works under atmospheric pressure and temperature, and can be integrated with most water treatment systems, which already have a capacity for removal of BOD/SS, without any pretreatment. Easy to operate and maintain, the system degrades dioxins in water under 0.1 pg-TEQ/l.

Contact: Kubota Corp., 1-3, Nihonbashi-muromachi 3-chome, Chuo-ku, Tokyo 103 8310, Japan. Tel: +81 (3) 3245 3336; Fax: +81 (3) 3245 3358



PCB extraction

Terra-Kleen Response Group Inc., the United States, offers mobile, on-site, solvent extraction technology to ensure environmentally safe and cost-effective treatment of soils and sediments tainted with pesticides, PCBs, polynuclear aromatic hydrocarbons, dioxins and furans, volatile/semi-volatile organics and petroleum hydrocarbons. The patented process employs a common industrial, non-toxic solvent and works at ambient temperature. The modular system assures cost-effective treatment of small and large sites.

Contaminated soil is excavated and loaded into solvent extraction tanks and clean solvent added from the solvent storage tank. This mixture is retained until organic contaminants are solubilized, isolating them from the soil. Contaminant-laden solvent is removed from the extraction tanks and pumped into the sedimentation tank. The suspended solids settle or flocculate in the sedimentation tank, and are then removed. After solvent extraction of the contaminants, any residual solvent in the soil is removed through soil vapour extraction and biological treatment. While treated soil is removed from the extraction tanks, contaminant-laden solvents are cleaned for reuse by a solvent regeneration unit.

Contact: Terra-Kleen Response Group Inc., 3970, Sorrento Valley Blvd., Suite B, San Diego, CA 92121, United States of America. Tel: +1 (858) 5588 762; Fax: +1 (858) 5588 759



Removing hydrocarbons

Mycelx Technologies Corporation, the United States, is offering a new compound to clean up offshore oil spills. This procedure can even be adopted for industrial, groundwater and runoff water applications by infusing filter cartridges with Mycelx so that pumped water can be easily treated. Mycelx is a patented curable polymeric surfactant technology that is infused in all Mycelx products.

Mycelx is the synthesis product of a reaction between a natural drying or semi-drying oil and various methacrylate esters. The resulting compound cross-links into practically any substrate. Mycelx retains the drying property of the natural drying oil, making both infusion as well as disposal of pollutants permanent. All Mycelx products instantly bond pollutants to their surfaces, thereby preventing the contamination from separating, emulsifying and releasing. Additionally, the use of Mycelx products doesnt lead to differential pressure while removing pollutants, a rare property in filtration methods.

Some application areas for Mycelx Hydrocarbon Removal Matrix cartridges include:
  • When lower discharge is required after an oil/water separator has removed the bulk of oil/hydrocarbons, a Mycelx post-polishing cartridge is used to further reduce the total petroleum hydrocarbon (TPH) level to below detectable limits (BDL);
  • When it is necessary to lower TPH, even sheen, to BDL;
  • In the presence of hydrocarbons other than just free fats, grease and oils e.g. semi-soluble compounds, pesticides, PCBs, aromatic hydrocarbons (BTEX), solvents, colloidal metals, MTBE, chlorinated organics, etc.;
  • In case a pre-polishing filter is required ahead of a membrane type filter, an activated carbon filter or ion exchange unit to protect it from oil/hydrocarbon and organic overload, degradation or blinding; and
  • When there is inadequate space to install large equipment like an oil/water separator, centrifuge or multimedia filter, yet the discharge must still be polished.

Contact: Mycelx Technologies Corp., # 961, Chestnut Street, Suite 106, Gainesville 30501, United States of America. Tel: +1 (770) 5343 118; Fax: +1 (770) 5343 117.


Remediation of PCB-contaminated soils

Sonic, Canada, has designed sonic generators based on new, patented Platform Technology to remediate PCB-contaminated soils. Platform Technology can apply sonic energy to chemical and biological reactions using sonic generators and is the only economical process to apply sonic energy on an industrial scale. Sonics method for remediating soils contaminated with PCBs is based on deagglomeration of soil utilizing the sonic generator and chemical dechlorination of PCB facilitated by the sonic generator to disperse and simultaneously activate the dechlorination agent in the process fluid. Process conditions allow dechlorination of PCB and removal of solvent to the extent needed for soil use or landfill in an industrial, commercial or residential site.

Sonic generators produce extremely intense agitation by low frequency sonic energy. This is achieved using a steel bar vibrating at its natural resonance frequency, a condition at which normal mechanical equipment will self-destruct. Vibrational sonic energy from the bar is transmitted into chambers through which fluid materials or slurries can be pumped. Materials are thus subjected to very intense sonic agitation, which has the effect of speeding up reactions and making them more complete (sonication). The Sonoprocesses can be applied to diverse industries such as agriculture, chemical manufacturing and processing, food processing, municipal waste treatment, petroleum, pharmaceutical, pulp and paper, potable and wastewater treatment and environmental remediation.

Contact: Sonic, Head Office, #2100-1066, West Hastings St., Vancouver, BC V6E 3X2, Canada. Tel: +1 (604) 7362 552; Fax: +1 (604) 7362 558



Treatment for dioxins and furans

Commodore Applied Technologies Inc. has launched Solvated Electron Technology (SET) as a means to remove hazardous constituents to below regulatory limits. SET, a patented non-thermal treatment process, is effective against the most toxic chemicals known to humans dioxins and furans. The process destroys pollutants without creating additional environmental crises while rendering the soil or any other matrix materials non-hazardous.

SET employs solvated electron solutions to create free electrons. In the case of chlorinated dioxins, the halogen atoms are stripped from the compound and converted into sodium chloride. SET is the only multi-matrix PCB chemical method approved for nationwide operation. Key features of this closed system include:
  • Original soils and other materials can be reused or disposed;
  • Dioxins are completely removed and no toxic secondary wastes or off-gases are produced;
  • Can be scaled to accommodate the desired level; and
  • Power, water and other outside support are kept to a minimum.


Decomposing of tough dioxins

Kurabo Industries Limited, Japan, is offering a new system to treat hard-to-decompose dioxins. Based on a combination of ozone and ultraviolet (UV) technologies, this treatment system offers benefits like separate ozone tower and UV tower, lower investment and operating costs, high dioxin decomposition ratio, etc. The system is applicable in a wide range of industrial fields like:
  • Wastewater disposal Seeping water from final waste disposal site, scrubber wastewater from incinerator gas scrubbers or wastewaters from wet dust collectors, ash storage and intermediate processing plants; and
  • Production systems associated with chlorinated organic compounds Effluent from ethylene dichloride rinsing facilities, wastewater from agri-chemicals production line and effluent from plastic manufacturing plants and processing facilities.

Contact: Kurabo Industries Limited, 14-41, Simokida-cho, Neyagawa, Osaka 572 0823, Japan. Tel/Fax: +81 (72) 8207 511/515.



Advanced solvent cleaning system

In the United States, MTA Technical Sales has launched next-generation solvent system, ENV 1500, in which the cleaning solution is brought to the parts rather than the other way round. This is achieved in a hermetically sealed process chamber where all the cleaning, rinsing and drying takes place. The chamber contains spray manifolds, ultrasonics and a 360C overflow weir to provide the most effective fluid agitation to clean intricate components. Following the final rinse, a low-pressure vacuum is created in the chamber to capture any remaining solvent molecules, which are passed through the solvent vapour recovery system (SVRS).

The SVRS unit comprises a cooled exchanger for condensation. Condensate is returned to the system storage tank that feeds used fluid to the solvent recycle system. The used fluid is recovered and stored in the reservoir tank, ready for the next cleaning cycle.

Contact: MTA Technical Sales, # 7507, Wystone Avenue, Reseda, CA 91335 2530, United States of America. Tel: +1 (818) 7049 700; Fax: +1 (818) 3427 668



Solvent recyclers

B/R Instrument Corp., the United States, offers fully automated 9700 MiniProCycler solvent recycler for reclaiming solvents in histology and industrial laboratories. Used solvent is placed in the system (8 l capacity) and the start button pressed to allow the recycling system to perform its errand. A microprocessor controller constantly monitors the system, checking all safety parameters. At the end of the recycling programme, the procedure stops automatically and indicates that the solvent is ready for reuse. The microprocessor is pre-programmed with up to 19 different solvent recycling protocols. Application areas include recycling of xylene solvents, alcohol solvents, xylene substitute solvents, acetone solvent, formalin recycling, etc.

Contact: B/R Instrument Corp., 9119, Centreville Road, Easton, MD 21601, United States of America. Tel: +1 (410) 8208 800; Fax: +1 (410) 8208 141



Solvent distillation equipment

In the United States, Fluid Energy Industrial LLC offers solvent recovery units from Finish Thompson Inc. In this system, the solvent is poured or pumped into the boiling chamber, which the operator lines up with a standard Stilbag. The chamber lid is sealed and power supplied to the system. An encapsulated heater radiates heat through the conductive walls of the chamber to heat the solvent. Vapours from the boiling solvent travel through a vapour tube and into a water-cooled shell-and-tube condenser, where it condenses into a 99+ per cent distillate, which is gravity-flowed into an approved 68 l or 250 l drum. When a visual check reveals no further distillate available, the operator shuts down the unit and allows it to cool, after which the remaining residue is removed via the Stilbag.

A small footprint facilitates easy storage for the Little Still JrE, which processes 14-23 l/shift. An optional exhaust hood is available to contain and exhaust vapours. LS-15E, LS-15IIE and LS-15IIE with Jetvac are skid-mounted systems, which are simple and easy to maintain. While model LS-55 can process 250-500 l/shift, LS-55STE operates with an optional steam boiler system. LS-55E comes with the Jetvac system to enable recovery of solvents with boiling points up to 260C.

Contact: Fluid Energy Industrial LLC, 2201, CrownPoint, Executive Dr., Suite A, Charlotte, NC 28227, United States of America. Tel: +1 (704) 8462 999; Fax: +1 (714) 5274 784



New solvent recovery systems

Tscort, the United States, is offering medium-sized solvent recovery units that have been designed with many uses in mind. Single on-site, multiple on-site and mobile designs are available. Chemicals with boiling points under 177C can be recovered, with standard materials. The basic recovery system employs fundamental distillation methods but is far more superior in both amounts recovered and efficiency. The Tscort unit can reclaim 20 per cent more than conventional solvent recovery systems, which have a recovery efficiency of 70 per cent.

Tscort system is ideal for various applications, especially site clean-up and site spills requiring a system or systems with a cost recovery time of less than six months. Its main use, however, has been in the marine industry to recycle acetone. Other recyclable materials include acrylic, alcohol, butyl acetate, ethyl acetate, ethylene glycol, ethyl ether, isobutyl acetate, isopropyl alcohol, lacquer diluent, methanol, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), methylene chloride, mineral spirits, toluene (1-2-3), toluol (aromatic hydrocarbon), turpentine gum, xylene (1-2-3), etc.

Contact: Ms. S. Rarick, Tscort, 106, Albion Place, Dept. 16, Atlantic City, New Jersey 08401, the United States.



Energy extracted from wastewater

Japans Ishikawajima-Harima Heavy Industries Co. Ltd. offers an internal circulation (IC) reactor for producing energy from high- and low-strength wastewaters. Based on the UASB concept of biomass granulation, the new system employs three phase separators. Notable features include separation of produced biogas in two stages within a reactor with a large height/diameter ratio. Gas collected in the first stage is used to generate a gas lift as well as internal liquid circulation. Two-stage design of the reactor allows for up to three times higher volumetric loading rates and less than half the hydraulic retention times compared with conventional UASB units. Anaerobic treatment of low concentration wastewater at low temperature is also effective.

Contact: Ishikawajima-Harima Heavy Industries Co. Ltd., 2-2-1, Ohtemachi, Chiyoda-ku, Tokyo 100, Japan. Tel: +81 (3) 3244 5967; Fax: +81 (3) 3244 5136.


Treatment of wastewater from pulp and paper mills

In Japan, Hitachi Plant Engineering and Construction Co. Ltd. is offering Deep Shaft process to treat pulp and paper wastewaters. In the new method, biochemical treatment of the effluent stream is carried out efficiently by dissolving ambient oxygen into the effluent stream. The shaft, having a bore of 1-6 m, is set up in the ground vertically, as deep as 50-150 m, and is partitioned into two sections down-flow and up-flow sections utilizing a cylindrical perpendicular wall.

Wastewater entering from the top flows down towards the shaft bottom as it mixes with the circulating liquid in the shaft. Air introduced into the down-flow section travels towards the bottom mixed with the circulating liquid, which rotates in the shaft at the rate of 1-2 m/s. By the time air reaches the shaft bottom, most of it is dissolved into the liquid, owing to higher hydraulic pressure. As such, this process completes the biological treatment positively and rapidly. Potential application areas include food and chemical industries, sewage treatment, flushing water recycling in office buildings, and many others.

Contact: Hitachi Plant Engineering and Construction Company Limited, 1-14, Uchikanda, 1-chome, Chiyoda-ku, Tokyo 1010 047, Japan. Tel: +81 (3) 3295 8960; Fax: +81 (3) 3292 4418



Treatment of electrogalvanizing effluents

Wastewater discharged from plating processes can be categorized into continuous and renewal wastewater. The latter places a markedly heavier treatment load and changes in the ratio between the two types of effluent streams tend to necessitate a marked change in how wastewater treatment plants must be operated. Matsushita Seiko Engineering Co. Ltd., Japan, provides a solution that separates wastewater into chrome-containing part and acidic/alkaline wastewater for collection. A water tank is provided for the renewal liquid so that wastewater, with as stable a quality as possible, can be delivered for treatment. It also enables fixed quantities to be supplied to continuous wastewater processes.

Designed to treat 64 m3/d of wastewater, the treatment procedure is based on coagulating sedimentation technology. For the continuous or acidic/alkaline fraction, pH of the wastewater is regulated to about 9-10.5 in the neutralizing tank and coagulated with zinc extracted. After separation and sedimentation, the pH is again regulated prior to discharge. In the chromium tank, pH is regulated to about 2.5 before it is lowered. Following mixing with the continuous wastewater, this stream is coagulated, isolated, sedimented and pH regulated before discharge.

Contact: Matsushita Seiko Engineering Co. Ltd., Japan.



Treating heavy metal wastewater

Matsushita Seiko Engineering Co. Ltd., Japan, offers technology for treating heavy metal wastewater generated during battery production. In this procedure, wastewater discharged from each stage is passed through a screen and stocked in a raw wastewater tank. Wastewater is then neutralized interlocked with a pH meter and coagulation reaction tanks. A sand filter removes carbon from the wastewater while a monitor tank helps determine if this stream is acceptable or not. Unacceptable water is returned to the raw wastewater tank or discharged as effluent if found okay.

Contact: Matsushita Seiko Engineering Co. Ltd., Japan.



Treating industrial organic effluents

Multiplate reactor technology from SNC Research Corp., Canada, can treat industrial effluents with high concentrations of organic matter. In this process, organic waste is partly converted into methane through an anaerobic biological process. Gas emissions are collected at the reactor outlet to be burned or to supply energy. The vertical reactor contains plates at three levels connected such that upward flow of liquids and gases is possible while preventing bacteria from falling to the reactor base. The plates serve to distribute the load and facilitate gases to be produced over several sludge beds. Water is pumped into the reactor from the bottom. A system capable of treating 500 kg/d of chemical oxygen demand (COD) requires a floor space of 60 m2. Alternating treatment for different varieties of effluent is also possible.

The reactor has been tested using effluents from a cheese factory, at scales of 1,200-450,000 l. Results indicate a removal rate of 90 per cent of COD with an organic load of 45 kg/m3/m3-d. Gas production yields up to 20 m3/m3-d have been achieved. Retention time varies from 12 to 40 h. The outgoing water can be discharged into municipal sewers. This system is ideal for readily biodegradable organic matter that is not toxic for the systems bacteria. It can easily handle organic loads of 2,000-60,000 mg/l COD. Principal gases recovered are methane (80 per cent) and carbon dioxide (CO2).

Contact: Mr. Bechara Safi, SNC Research Corp., Place Felix-Martin, 455, Rene Levesque Ouest, Montreal, Quebec H2Z 1Z3, Canada. Tel: +1 (514) 8666 635; Fax: +1 (514) 8660 600; E-mail:   Or Ms. Catherine Mulligan, Research Engineer, SNC Research Corp., Canada.



Advanced water treatment solutions

ITT Industries, the United States, has launched a membrane filtration system for advanced water treatment solutions. Aquious industrial dual-stage membrane bioreactor (MBR) integrates optimized biological treatment performance with high-integrity reinforced hollow-fibre membranes. This fusion can assure treated water of exceptional quality with low operating costs.

Contact: ITT Industries, United States of America.



Segregating metals from wastewater

The United States-based Approved Environment Inc. offers a patented process to remove all but a trace of metals from effluents. Chemical mixtures referred to as 8856A and 8856B are used in this method to effectively isolate a variety of metals before wastewater is discharged into treatment facilities. Non-hazardous sludge is produced by this process, which requires normally available equipment present in a wastewater treatment unit. Potential applications include precious metal plating and recovery, waste streams from PCB manufacture, plating bath and rinse solutions, wastes generated during paint manufacturing, oil solutions containing copper from automotive manufacture, organic dyes used for anodizing operations, wastes from copper and nickel processing, and petroleum refining residues. Recovery of metal salts could be employed for recycling, wherever economically feasible.

A unique feature of the process is that metals are removed independent of pH, which allows a wide range of metals precipitation to take place in one optimum pH. Other benefits include minimum supervision, lower chemical requirement, less solids production, cost savings accrued by sending concentrated liquid wastes for treatment off-site, etc.

Contact: Approved Environment Inc., P.O. Box 47895, Indianapolis, IN 46247 0895, United States of America. Tel: +1 (317) 8629 440



Removal of heavy metals from effluents

McGill University, Canada, offers a precipitation process for removing heavy metals like lead, cadmium and zinc from aqueous media. The process operates over a wide range of pH and residual concentrations of metals comply with regulations for effluent streams. The precipitates offer excellent settling and filtering traits while the precipitating agent is regenerated in pure form.
The process features selectivity for heavy metals over alkaline earth metals. Application areas include toxic metals removal and recovery, electroplating processes, battery, and mining and metallurgical fields.

Contact: Ms. Katya Marc, McGill University, Canada. Tel: +1 (514) 3983 355; Fax: +1 (514) 3982 850

E-mail:  Or Office of Technology Transfer, 3550, University St., Room 104, Montreal, Quebec H3A 2A7, Canada. Tel/Fax: +1 (514) 3984 200/3981 482.



Dry type low-temperature ESP

A dry type low-temperature electrostatic precipitator (ESP) offered by Kansai Electric Power Co. Limited, Japan, can be utilized to decrease particulate levels in flue gas streams. The ESP has two electrodes, a discharge electrode and a collecting electrode. When smoke containing particulates is ionized while passing between these two electrodes, the particulates are negatively charged. Attracted by positive electricity, the particulates adhere to the collecting electrode. Accumulated pollutants, periodically hammered, fall to the bottom of the precipitator and are removed.

Contact: Kansai Electric Power Co. Limited, Japan.



Wet Electrostatic precipitators (ESPs)

Croll-Reynolds, the United States, offers wet electrostatic precipitators (ESPs) with high capture efficiencies for sub-micron particulate and mists by employing electrical forces to remove suspended particles from a gas stream. Electrostatic precipitation consists of three stages charging the particles to be collected through a high-voltage electric discharge, collecting the particles on the surface of an oppositely charged collection electrode surface and cleaning the surface of the collecting electrode. In case of wet ESPs, the collecting electrode is cleaned by washing its surface with a liquid, rather than mechanically rapping the collection plates. This has beneficial impacts on the nature of particles which can be captured, performance efficiencies as well as design parameters and operating maintenance of the equipment.

Since wet ESPs operate in a wet environment, they can easily handle a wide variety of pollutants and gas conditions. The collection surface is continually wet to obtain a dilute slurry that flows down a collecting wall and into a recycle reservoir. The collecting walls never build up a layer of particulate cake. Consequently, there is no deterioration of electrical field due to high resistivity. Power levels in a wet ESP can be dramatically higher than in a dry ESP, improving collection efficiency and eliminating any re-entrainment of particulates into the gas stream, thus avoiding the necessity to have multiple fields. Wet ESPs can be designed for various configurations depending on the site and process. Series arrangement of the modules helps overcome current suppression while a parallel configuration could handle large air flows.

Contact: Croll-Reynolds Clean Air Technologies, P.O. Box 668, 751, Central Avenue, Westfield, NJ 07091 0668, United States of America. Tel: +1 (908) 2324 200; Fax: +1 (908) 2322 146



Acid gas purification techniques for H2S

Kobe Steel Limited, Japan, offers wet type desulphurization process to recover hydrogen sulphide (H2S) from exhaust streams. Developed by British Gas Corp., the Stretford process is applicable to any gas, e.g. coke oven gas, natural gas, oil refinery gas, coal gas, etc. In the absorber, the gas to be treated is fed counter-current to the absorbing solution to remove H2S. Packings used in the absorber are custom-designed splash-type plates. The absorbent is delayed at the bottom of the absorber while H2S in the solution is converted into elemental sulphur. The solution is then sent to the oxidizer, where air is supplied to regenerate the solution, allowing elemental sulphur to float in the slurry. Sulphur-rich froth is concentrated by a filter or centrifuge to form sulphur cake, which is reslurried with water and heated to recover molten sulphur of high purity using a sulphur separator. Solution regenerated in the oxidizer is sent to the balance pit and then back into the absorber.

H2S content can be lowered to less than 0.1 ppm at atmospheric and higher pressures. Simple operation and energy savings can be achieved as the absorption and regeneration are performed at temperatures of 30-40C. Chemicals used in this process are stable, non-toxic and easy to treat. The absorbing solution is weakly alkaline (pH 8.5-9.0) and non-corrosive.

Contact: Kobe Steel Ltd., Japan.



ESP for high-resistivity dust

The dust collection efficiency of an electrostatic precipitator (ESP) is dependent on the dusts electrical resistivity. In case of high-resistivity dust, a phenomenon known as back corona problem, efficiency is much reduced. Mitsubishi Heavy Industries Ltd. of Japan is offering new energization systems to suppress back corona. Intermittent energization is a method which de-energizes before the voltage across the dust layer exceeds the back corona start voltage and re-energizes when it returns to the original level. A system based on this process facilitates energization and de-energization at intervals, by means of thysistor control, to enable an ESP to operate efficiently. In the pulse energization process, an instantaneous and high steep voltage is repeatedly applied to the ESP. This system, developed as a follow-up to intermittent energization, enables higher performance of the ESP.

Intermittent or pulse energization processes enable supply of sufficient voltage and current to charge high resistivity dust while concurrently suppressing the occurrence of back corona. This results in a compact ESP with high collection efficiency and lower energy needs. Suitable for coal-fired boilers and sintering machines, the energization systems can be applied to existing ESPs.

Contact: Mitsubishi Heavy Industries Limited, Japan.



New NOx filter

A new catalytic conversion system from Paul Scherrer Institute (PSI), Switzerland, filters 90 per cent of nitrogen oxides (NOx) from diesel exhausts. Based on a refined technology, the process utilizes a non-toxic urea solution, which futuristic vehicles could carry in a separate refillable tank. PSIs new selective catalytic reduction (SCR) method offers several advantages over other SCR units. It can prevent ammonia produced during the reaction from escaping, achieved by employing an ingenious regulating system. NOx is removed effectively as the amount of urea added continuously adapts to different drive phases. Both NOx and soot are lowered. Efforts are underway to achieve zero-emissions.

Contact: Paul Scherrer Institute, 5232, Villigen, Switzerland. Tel: +41 (56) 3102 111; Fax: +41 (56) 3102 199.


Multi-cyclone dust precipitator

Kondo Plant Engineering Co. Ltd., Japan, offers KSM-S type axial-flow inversion system multi-cyclone dust precipitator. In this system, each gas-flow inlet is provided with guide vanes. Dust-containing gas is led to the interior of a cylinder at high speed. As such, a rotating movement is applied to the guided dust-containing gas and a strong centrifugal force generated. Precipitating speeds hundreds or thousands times as large as gravity can be achieved, enabling effective separation and elimination of particles. Some notable characteristics of this low-cost system include:
  • High precipitation efficiency using plural small-calibre cyclones with strong centrifugal force;
  • Wide range of usage in normal heavy oil boilers like 1,000-32,000 kg/h of evaporation quantity (350C high-temperature exhaust gas);
  • Fully automatic dust exhaust system; and
  • Easy to maintain and inspect.

Contact: Kondo Plant Engineering Co. Limited, Japan.



Reducing NOx

In the United States, Glennan Microsystems, Goodrich, ZIN Technologies and Case Western Reserve University are involved in a project focusing on developing an active fuel and emission control system to lower NOx emissions from gas turbine engines by 70 per cent. The Active Fuel and Emissions Control (AFEC) system will enable new and existing aircraft engines, electrical power generators and marine propulsion engines to comply with NOx standards set by the Environmental Protection Agency for 2010.

The projects core innovation will be the development of micro-electro-mechanical system (MEMS) silicon carbide (SIC) sensors and actuators that can bear temperatures up to 600C in the combustion chamber. Integration of SIC MEMS devices with combustion hardware has not yet been demonstrated and would be a major breakthrough if achieved. While Glennan will provide expertise to develop SIC-based MEMS, Goodrich will handle combustion control systems and ZIN will contribute its knowledge of developing diagnostics for power and propulsion systems in harsh environments. In addition, sub-contractors Pentalim, Sienna Technologies, FLX Micro and the University of Cincinnati will help overcome technical and business obstacles involved with bringing the system into the market. Design, fabrication and testing support of the system will be undertaken at the NASA Glenn Research Centre.

Contact: Glennan Microsystems Inc., 20445, Emerald Parkway Drive, S.W., Suite 200, Cleveland, Ohio 44135, United States of America. Tel/Fax: +1 (216) 8986 400/550



Thermal oxidizer

Conox Ltd., Finland, has developed technology for complete destruction of organic matter in waste liquors without harmful emissions. The new thermal oxidizers are available in capacities ranging from 100 kg COD/h to 1,500 kg COD/h. For higher capacity, standard units can be set up in parallel. Designed to burn low-calorific liquor by using pure oxygen instead of air, this system lowers by 20 per cent the amount of gas required for combustion. The device is pressurized to 10 bar, lowering the gas volume to one-tenth of the volume at atmospheric pressure.

Contact: Conox Ltd., Kaanaankatu 3 A, Fin 00560, Helsinki, Finland. Tel: +358 (9) 8683 6490; Fax: +358 (9) 8683 6700




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