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VATIS Update Waste Management . Jul-Aug 2005

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Waste Management Jul-Aug 2007

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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VATIS Update Non-conventional Energy Apr-Jun 2017
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VATIS Update Biotechnology Apr-Jun 2017
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VATIS Update Waste Management Oct-Dec 2016
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VATIS Update Ozone Layer Protection Sep-Oct 2016
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Contents

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IN THE NEWS

Aid to governments in management of PCBs

A toolkit is being released by the Secretariat of the Basel Convention on the Control of Transboundary Movements of Hazardous and Other Wastes to support decision-making in the inventorying and management of polychlorinated biphenyls (PCBs) and PCB-containing equipment. PCBs, which fall under the scope of the Basel Convention, are to be phased out by 2025 under the Stockholm Convention on Persistent Organic Pollutants (POPs).


The toolkit, PCB Inventory and Management Decision Supportive Tool (DST), is the product of experience gathered from PCB-related country projects in C?d?Ivoire (1997 and 2000-2001), the Gambia (2002) and Thailand (2003), besides other PCB-related activities carried out in the context of the Basel Convention?s implementation. The toolkit will aid government officers and field managers in carrying out inventories of PCBs and PCB-containing equipment in an efficient and organized fashion. It includes a risk-assessment dimension and provides concrete recommendations as well as instructions for the management of equipment being used or to be discarded. In addition, the toolkit will contribute to the efforts of relevant national or provincial authorities in the collection, processing and organization of PCB-related data. It will also support medium- and long-term planning related, for example, to the preparation of PCB-disposal plans or trans-boundary movements of PCB waste. The toolkit has been developed in Access language for ease of use by Parties to the Basel and Stockholm Conventions.


This first version of the toolkit shall be updated after testing by parties to both Conventions.


Website: www.I-newswire.com

China to tackle hazardous waste

The State Environmental Protection Administration of China has begun a five-city pilot project to ease the environmental problems caused by hazardous waste. Chongqing, Shenyang, Wuhan, Xi?an and Harbin ? all of which suffer from severe environmental and health problems caused by pollution ? have been ordered to closely regulate firms that produce dangerous chemicals, and to better enforce existing environmental protection laws.


Enforcement of laws already on the books face an uphill challenge, reported the official news agency, Xinhua. There are so many companies involved in illegal and careless activities that it would be very nearly impossible to stem illegal transport and dumping of hazardous waste, officials said. The five municipalities have also been instructed to set up recycling and treatment systems for chemical hazardous wastes. Successful solutions found through the pilot project will be applied across the nation.


Website: www.washingtontimes.com

Peak time for Beijing to scrap electronic appliances

Experts from the Academy of Social Sciences, Beiijng, have stated that the peak time has arrived for Beijing to scrap its electronic appliances. They predict that 115,200 tonnes of electronic wastes will be produced in Beijing by 2006. Among these are 3.576 million TV sets, refrigerators, computers, washing machines, air-conditioners and 2.345 million cell phones. By 2010, this number will rise to 158,300 tonnes.


According to associate researcher Mr. Liang Haoguang, residents of Beijing bought about 1,358,000 TV sets, air-conditioners, refrigerators and washing machines during 1990-95. With average lifespan of 10-15 years, these household appliances are gradually becoming waste after 2003. The lifespan of computers and cell phones is usually three to six years, so their scrapping peak time has already arrived too.


China has become a major dumping ground for electronic waste and risks becoming the high-tech waste bin of the world, posing hazards for its people and the environment. Although China has banned electronic waste from being imported, companies still illegally export such waste there while a lot more is generated domestically, said Greenpeace campaigner Mr. Yue Yihua. Most of the waste that is imported comes from countries of the developed world, such as the United States, Europe and Japan.


Website: www.english.people.com.cn

Trash becomes cash in Bangladesh

At the Matuail solid-waste dumpsite just outside of Dhaka, Bangladesh, sprawling mountains of garbage rot on 52 acres of land, making a toxic brew of greenhouse gases and bacteria. The site, the only one for this city of 10 million, is 90 per cent full. Making matters worse, the waste here represents below 40 per cent of the 3,200 tonnes produced each day, since the municipality lacks the funds and manpower to collect it all. The rest is left in the streets and already-strained sewers.


Mr. A.H. Md. Maqsood Sinha and Mr. Iftekhar Enayetullah, founders of the innovative non-governmental organization Waste Concern, have shown that all this trash can not only be managed but turned into a very profitable resource using simple technology. At the Green Road government colony in downtown Dhaka, five Waste Concern employees go door to door collecting refuse from 800 households, hauling it by rickshaw vans to a nearby shed. There they sort out any inorganic material before placing the trash into five brick bins. With a little help from micro-organisms, the natural climate here takes care of the rest, turning the heaps of rotting garbage into valuable biofertilizer.


Each month, the plant produces 3 t of biofertilizer, which sells for about US$0.04 per kg. The revenue is adequate to make the operation self-sustaining, covering all production costs and providing well-paying jobs to employees. As most food consumed in Bangladesh is fresh and not packaged, the waste is 80 per cent organic and perfect for composting. The model has proved so successful that the government has helped Waste Concern replicate it in 14 cities in the country, bringing waste services to 100,000 people. By diverting more than 50,000 t of waste a year from dumping, their efforts also produce 400 t of organic fertilizer a year, which is in demand by farmers across the country.


Website: www.csmonitor.com

India drafts e-wastes assessment manual

India?s Ministry of Environment and Forests is preparing a draft manual on assessing electronic wastes (e-waste). The manual is being drafted with the help of the Central Pollution Control Board, GTZ, the German agency for technical cooperation, and EMPA, a Swiss laboratory for material testing and research. It will contain a database format for documenting and recording waste from electronic and electrical equipment (WEEE) at a centralized place. The manual will provide a standardized approach and methodology for assessment of e-waste in major cities.


The drafting of the manual follows a national study sponsored by the Ministry in collaboration with GTZ and EMPA in January, the preliminary estimates of which show that India produces 146,000 t of e-waste annually. The highest contribution to WEEE is from Maharashtra, followed by Andhra Pradesh and Tamil Nadu. The highest e-waste producing cities are Mumbai, Delhi and Bangalore. It is estimated that 1.38 million personal computers become obsolete in the business sector and individual households generate almost 1,050 t of e-waste every year. Bangalore, the IT capital of India, alone accounts for 30,000 obsolete computers per year that ultimately end up as e-waste.


Website: www.hindu.com

First Indian e-waste management unit in Bangalore

The Government of India plans to prepare a report listing the best practices of e-waste management in a move to manage e-waste recycling effectively. The first e-waste management unit in the country would come up in Bangalore soon, said Dr. D.C. Sharma, Zonal Officer, Southern Region of the Central Pollution Control Board (CPCB). The unit is to have a capacity of managing two tonnes of e-waste per day. CPCB has already awarded the unit ?consent for operation?.


As of now, several local NGOs are carrying out an inventory of e-waste in and around Bangalore. A second unit in Bangalore for managing 10 tonnes of e-waste per day is in the pipeline, Dr. Sharma added. CPCB plans to start a registration process for e-waste management units, following which all the IT companies in Bangalore would be advised to dispose off their e-waste at these registered e-waste disposal units.


Website: www.sify.com

Malaysian states to jointly tackle waste problem

All states in Malaysia have agreed to a federal proposal on a new approach for managing the country?s solid waste problem. Datuk Seri Najib Tun Razak, the Deputy Prime Minister, said that the new system would have an integrated approach involving the use of landfills and incinerators. ?The current system is riddled with problems, including over payment and poor service,? added Datuk Najib. The Housing and Local Government Ministry had looked at various systems in developed countries, and all states had agreed to adopt a new approach if it would lead to better service.


Deputy Information Minister, Datuk Donald Lim Siang Chai, said that the Malaysian government spends more than US$100 million a year on waste disposal. This could be reduced by more than US$23 million if the people were to reduce their waste production by 22 per cent. Malaysians produce 17,000 t of garbage daily, which is projected to rise by 2 per cent every year. Recycling measures have failed to achieve the desired result, with only 3 per cent of the waste being recycled annually, he added.


Website: www.thestar.com.my

Malaysian firms invest in waste management

The Malaysian company Pentai Holdings Berhad will invest US$5 million for 30 years of waste management in a Bandung hospital, according to Antara News Agency. If the project proved successful, it would serve as an example to other cities, said Mr. Nu?man A. Hakim, West Java?s Deputy Governor. He added that the Malaysian company is conducting a feasibility study at its own expense.


In the meanwhile, the ?Recycle PC? campaign launched jointly by the waste management company Alam Flora Berhad and the Association of the Computer and Multimedia Industry of Malaysia (Pikom) is picking up steam since its launch in March 2005. By the end of April, the campaign had collected 816 computers and peripherals. Working PCs would be donated to NGOs, while unworkable components would be sold to PC recycling factories and the proceeds channelled to NGOs, Alam Flora officials stated.


Websites: www.bernama.com  & www.star-techcentral.com

Philippine city puts waste management law into practice

Starting 1 July 2005, the Cebu city government will fully implement the Republic Act 9003, otherwise known as the Ecological Solid Waste Management Act, and its parallel local ordinances. This is in accordance with the memorandum of agreement signed between the city government and the Integrated Bar of the Philippines National Environmental Action Team for the enforcement of proper waste management. Following the agreement, the city council adopted City Ordinance No. 2031 that covers the ?no segregation, no collection policy? as well as City Ordinance 1361 creating the solid waste management board.


After a dry run in the latter half of June, those who fail to segregate their garbage would be penalized. People have to store garbage in different containers classified as biodegradable, non-biodegradable, reusable or recyclable, hazardous or special, and bulky and white goods. Those who fail to comply with the law would be fined P1,000-5,000 (US $18-90), sentenced to imprisonment, or both at the discretion of the court. First-time violators who opt for an out-of-court settlement shall be slapped with P500-compromise fee.


Each locality (barangay) already has one Cebu Environmental Sanitation Enforcement Team, whose members are deputized by the mayor, after due training on the solid waste management law, to apprehend any person or head of a juridical entity that is caught violating any of the provisions of the law. Under the ordinance, it shall be the task of the respective barangays to collect the reusable and biodegradable wastes while the city government shall manage only the non-biodegradable, bulky, special and other such forms of waste listed in the national law.


Website: www.thefreeman.com 

Korea to recycle old cell phones

The Republic of Korea has started a campaign to collect and recycle abandoned cell phones. The Ministry of Environment said that the campaign is designed to encourage elementary and middle school students in Seoul and Kyonggi Provinces to recycle obsolete and unused mobile phones. The ministry would consider expanding the campaign throughout the country if it yields good results. The move is part of the Ministry?s efforts to implement the system of ?Extended Producer Responsibility (EPR)? for cell phones.


The government initiated the EPR system in 2003, requiring manufacturers to recycle their products. It added cell phone makers to the list of manufacturers from this year, as cell phone handsets can be detrimental to the environment if they are not disposed of properly. According to the ministry, around 9 million out of 13 million cell phones replaced every year remain at home, posing the risk of them being dumped into landfills at some stage. To address this, the Ministry plans to apply the cell phone collection campaign to apartment complexes, beginning the campaign with five large apartment complexes in Seoul. If successful, the campaign would be gradually expanded to include all apartment complexes in Seoul in October and those in other cities next year. The ministry also said it will set up an effective collection and recycling system for handsets.


Website: www.times.hankooki.com

Thailand takes steps to contain noxious waste

Groceries and wards selling mobile phones in major cities across Thailand will be provided with free waste bins in an effort to collect used cell phone batteries and other electronic equipment. The move is aimed at reducing the effects of waste on human health and the environment.
The programme, which takes effect on 29 June, is being sponsored by Thailand?s Environmental Management Department. Intitially, at least 5,000 waste bins will be provided. The Department will also take other measures to control waste containing noxious chemicals.
About 9 million batteries are estimated to be discharged each year in Thailand, the annual import of cell phones touching 28 million units in the period 2000-03.


Website: www.vnagency.com

PLASTIC WASTES

Plastic oil for fuel economy

Recycled plastic bottles could one day be used to lubricate cars engine, according to researchers at Chevron Energy Technology Company and the University of Kentucky, the United States, who in laboratory experiments converted waste plastic into lubricating oils. These oils derived from polyethylene could help improve fuel economy and reduce the frequency of oil changes. This technology potentially could have a significant environmental impact. It could make a difference in communities that want to do something positive about their waste plastic problem, especially if there is a refinery nearby that could do all of the processing steps, stated the pilot studys lead author Dr. Stephen J. Miller, a senior consulting scientist at Chevron.


Most of the recyclable plastic is polyethylene, which the scientists showed can be broken down by heat into a wax that can be converted into a high quality lubricating oil. Of the plastic used in the study, about 60 per cent was converted into a wax with the right molecular properties for further processing to make lubricating oil for uses such as motor oil or transmission fluid. These high quality oils derived from wax could assist auto manufacturers in meeting fuel economy specifications, said Dr. Miller.


Website: www.sciencedaily.com

Two-stage pressure gasification system

In Japan, a gasification system for chemical recycling, developed and commercialized jointly by Ube Industries and Ebara Corporation, has been bestowed Japans Science and Technology Award in the development category. The two-stage pressure gasification system employs a pioneering technology called the Ebara-UBE Process (EUP) technology for converting waste plastic into gas. The resulting converted gas is primarily composed of hydrogen and carbon monoxide, with almost no trace of hydrocarbons.


The process takes place in a dualsystem comprising a low-temperature gasifier and a high-temperature gasifier, both operating under pressure. Oxygen and steam are used for thermal decomposition and partial oxidation of plastic, without the need for sorting and separation. The resulting converted gas can be used to synthesize ammonia and produce other raw materials for the chemical industry. Inorganic substances and metals contained in waste plastics are recycled as part of the two-stage pressure gasification system. Inorganic materials are recovered as granulated slag for use as a raw material in cement and other construction materials, while recovered metal scraps can be recycled to significantly reduce the burden on final disposal sites.


The EUP technology fully addresses environment concerns. Dioxins are thermally decomposed in the high-temperature gasifier at temperatures exceeding 1,300C, and then cooled instantly to under 200C to prevent dioxin synthesis and resynthesis. Other major environmental benefits include recycling of converted gas for use as a chemical raw ingredient, leading to a reduced dependence on fossil fuels and lower CO2 emissions.


Contact: Ube Industries Ltd., Investor & Public Relations Dept., Corporate Planning & Administration Office, Seavance North Bldg., 1-2-1 Shibaura, Minato-ku, Tokyo 105-8449, Japan. Tel: +81 (3) 5419 611; Fax: +81 (3) 5419 6230.


Website: www3.ube-ind.co.jp

Innovative carton recycling plant

Alcoa Aluminio, Tetra Pak, Klabin and TSL Ambiental have together set up the worlds first packaging carton recycling facility at Piracicaba, Brazil. The plant uses plasma technology to totally separate aluminium and plastic components from packaging cartons. This innovative process constitutes a major enhancement to the current recycling process for carton packaging, which up until now, separated paper, but kept plastic and aluminium together.


The plasma technology uses electrical energy to produce a plasma jet at 15,000C to heat the plastic and aluminium mixture. The plastic is transformed into paraffin and the aluminium is recovered in the form of high-purity ingot. The new facility has the capacity to process 8,000 t/y of plastic and aluminium, corresponding to recycling approximately 32,000 t of aseptic packaging. The emission of pollutants during the recovery of the materials is minimal, handled in the absence of oxygen, without combustion, regsitering an energy efficiency rate close to 90 per cent.


Website: www.est.org.uk

Rubber products from waste tyres

ENSD Co. Ltd. of the Republic of Korea has developed a process for recycling waste tyres by melting down and moulding them into new products. The process is complex because the tyres consist of cross-linked polymers. The technology is claimed to be the most economical and environment friendly among the current waste tyre recycling technologies. Many new products such as kerb blocks, outdoor benches and flooring can be made in different colours and designs using the reclaimed rubber. The process creates a double surface layer of ethylene-polypropylene terpolymer powder and tyre powder. The products have excellent weather resistance and durability, and are easy to maintain and clean.


Contact: ENSD Co. Ltd., 379-8 Gyochon-ri Jain-myeon, Gye- ongsang-si, Gyeongsangbuk-do, Seoul 712-852, Republic of Korea. Tel: +82 (53) 854 2266; Fax: +82 (53) 854 4354


E-mail: ksm4776@hanmail.net

Recycling TetraPak cartons

A start-up venture of the Cambridge University, the United Kingdom, has developed a unique recycling technology for the millions of TetraPak cartons that are thrown away each year. EnvAl, employing microwave-induced pyrolysis a form of heating to release compounds plans to extract reusable aluminium and plastic from the packaging cartons, which can then be easily recycled.


Dr. Carlos Ludlow-Palafox, EnvAls co-founder, claims the technique to be unique. Current technologies extract from TetraPak cartons the 70 per cent paper content for reuse as fibre in cardboard, before remaining plastic and aluminium (25 per cent and 5 per cent, respectively) are sent to landfill site. EnvAl is setting up a pilot plant with the 150,000, which it won in the Cambridge Universitys Entrepreneurs Business Creation Competition, to test the technology. The business model, which secured the funding, relates to a mobile recycling plant that can be transported from one plant to another, thereby saving substantially on the transportation costs incurred with a low-density waste product like cartons.


Website: www.e4engineering.com

Bottle-to-bottle PET recycling

At present, PET bottles are recycled mainly for technical applications, as the quality of this recycled material is not satisfactory for food containers. Buhler AG of Switzerland has developed an economical process to upgrade the flaked material from used PET bottles to standard quality pellets suitable producing food-contact bottles. From an ecological point of view, the recycling of post consumer PET bottles to new PET bottles offers advantages, such as in terms of energy balances.


The Buhler bottle-to-bottle process converts washed PET flakes from post-consumer bottles into bottle- grade pellets, using a plant that integrates decontamination in the Ring Extruder and continuous crystallization and solid-state polycondensation in the SSP system. The bottle- grade PET pellet that results fulfils most food approval requirements, including that of the FDA. The production costs of bottle feedstock from the recovered PET bottles are lower in comparison with virgin PET bottle material.


Contact: Bhler AG, CH-9240 Uzwil, Switzerland. Tel: +41 (71) 955 2389; Fax: +41 (71) 955 3851


E-mail: buhler.uzwil@buhlergroup.com 


Website: www.buhlergroup.com

Plastics reclaiming machinery

Eurohansa Inc., the United States, offers single machines, as well as complete and automated lines for plastics recycling and reclaiming. Eurohansas ZTLP series consists of low-noise, low-speed, single-shaft shredders that can be added to any reclaiming/recycling system. These heavy-duty shredders allow batch-dumping of materials, whether in baled or loose form. Using conveyors, self-dumping hoppers and front-end loaders, these PLC units perform all grinding functions without the need for supervision. The ZTLP shredder comes in more than 30 throughput capacities ranging from 90 kg/h to 9,000 kg/h, with classifying screens of 13 mm to 101 mm.


The ZTH horizontal feed units provide the user with a one-step size reduction system. A vibrating in-feed table (available in any length) transports the materials into the cutting chamber, via gear-driven, feed-controlled, in-feed rollers. An alternative to shredder/granulator combinations is the ZSM cutting mill that offers over 6,000 hours of service before a tool change is necessary. A wide variety of design features and options are available on these mills.


Contact: Eurohansa Inc., P.O. Box 6416, High Point, NC 27262, United States of America. Tel: +1 (336) 885 1010; Fax: +1 (336) 885 1011


E-mail: info@eurohansa.com


Website: www.eurohansa.com

BIOMEDICAL/HEALTHCARE WASTES

Plasma pyrolysis of medical wastes

In general, hospital wastes contain 10 per cent infectious components, besides toxic heavy metals such as lead, cadmium and Mercury. Jeonju University and Young Engineering Co. Ltd. of the Republic of Korea have developed a plasma pyrolysis technology to treat hospital waste for converting oxidizable/reducible compounds into stable materials.


The process developed integrates plasma torch, pyrolysis chamber and melting furnace designs, and post-management technologies. A plant for pyrolysis-melting plasma system (250 kg/h capacity) consists of reactors (pyrolysis and melting furnaces), combustion furnace, heat exchanger, quencher, mixing chamber, bag filter, stack and slag discharger. Plasma torch is made up of a negative electrode installed at the one end of a cylinder-shaped case, a positive electrode at the other end, two air-input parts that supply a vortex of air to the inside of torch, a water jacket for cooling electrodes, a water supply system, and an outlet for discharging used water.


Analyses showed that the pyrolysis chamber contained 7-15 per cent CO, <150 ppm NO and 0.5 per cent CxHy when the air supplied to the pyrolysis chamber contained 1-2 per cent oxygen. The highly concentrated CO was burned in the second combustion chamber, and its concentration was less than 20 ppm in the stack. After treatment, metals such as lead, mercury, cadmium, hexavalent chromium and arsenic were not detected.


Contact: Young Engineering Corporation Ltd., Seoul, Republic of Korea. Tel: +82 (2) 326 0762; Fax: +82 (2) 326 0761


E-mail: young-eng@young-eng.co.kr


Website: www.apec-vc.or.kr

Cutting-edge medical waste treatment system

Cutting-edge technology developed by Bioservices Group Inc., Canada, has made medical wastes treatment easier and more eco-friendly. External Steam Agitation (ESA) uses simple steam properties to process medical wastes to a sterile level permissible for distribution to landfill. Claimed to have the most advanced control system to date in the industry, ESA has an internal rotating arm that macerates the waste. Use of a jacketed pressure vessel with an internal arm assembly lowers steam consumption.
A few of the features that make ESA raise the bar on the regulatory standards for medical wastes treatment include multiple pass-coded parameter changes, programmed maintenance schedule, programmable biological indicator test schedule, text print-out, load weight print-out and programmable drying cycles.


Contact: Bioservices Group Inc., 10, Romeo Court, North Bay P1B 9R5, Canada. Tel: +1 (705) 8405 358; Fax: +1 (705) 4947 880


Website: www.bioservicesgroup.com


Website: www.news.thomasnet.com

Biomedical waste sterilizer

Jain Hydraulics Pvt. Ltd., New Delhi, India, is offering steam sterilization equipment for treating biomedical wastes. Bio-Clave is an advanced form of autoclave in which the waste is heated indirectly by introducing steam into the jacket instead of the main chamber. Moisture in the waste is used to generate the necessary steam pressure for optimum sterilization at minimum cost.
Bio-Clave is totally microprocessor controlled and automated; human intervention is needed only for loading waste bags into the unit. Pre-shredding done inside the vessel results in homogeneous waste that allows for maximum penetration of steam into the waste. The unloading of the waste is by the tumbler arm and tumbler tilt, which automatically operate in full synchrony, discharging the dry waste onto the shredder and then onto the storage bins (optional).


The rotating arm, which makes the waste to continuously move around, ensures total sterilization and avoids any cold spots. The unit treats the waste to the level of 6-log, equivalent to 99.999 per cent. Only one operator is required, for monitoring and control. At the end of the operation, the totally sterile steam in the main chamber is sucked out and drained into the sewer at very high temperature and pressure. The volume of waste on treatment reduces by up to 85 per cent and the weight by up to 70 per cent.


Contact: Jain Hydraulics Pvt. Ltd., 10066 Multani Dhanda, Street No. 1, Paharganj, New Delhi 110 055, India. Tel: +91 (11) 2361 0291, 2362 9689, 2352 3966; Fax: +91 (11) 25504343


E-mail: info@jainhydraulics.com


Website: www.jainhydraulics.com 


Making cash from biomedical trash

Ship to Shore Disposal Services Inc. of Dartmouth, Canada, which specializes in disposal of international garbage, has acquired technology and equipment to treat and dispose of the biomedical waste generated by Nova Scotia province. The process, called hydroclaving, sterilizes the waste at temperatures of up to 132C. The waste is put into a hydroclave with a double-walled chamber through which steam is circulated. The waste gets fragmented inside the chamber and its moisture gets heated to turn into steam. When the waste is dehydrated, reducing its volume by as much as 40 per cent, it is rendered inert and suitable for landfill.


The hydroclave can handle a load of up to 337.5 kg per hour. There are no air emissions from the process, and the steam taken from the waste is condensed back to water and discharged into a sanitary system. Ship to Shore is setting up a firm, Bio-Medical Waste Disposal Services, to treat the provinces biomedical waste. The technology, developed in Ontario, and the equipment have undergone 37 tests with biological indicators and have met or exceeded all industry standards.


Website: www.safecleanup.com

Retort autoclave for medical waste treatment

George K. Moss Co., Inc. of Alabama, the United States, is back in the market with retort type autoclaves, provided with an enhanced user-friendly, remote monitoring PLC control system for treating medical waste in hospitals of any size. The Moss approach to onsite medical waste disposal is claimed as the most complete method for hospitals for ensuring acceptable processing of infectious waste materials.


The red bag carts from the hospital floors are loaded onto cart tippers with spill chute that dumps the bags into stainless steel autoclave carts. Each cart is then pushed into the autoclave for processing. Once processed, the carts are removed from the autoclave and are rolled to the compactor/container or the optional shredder cart dumper. Handling of treated and other wastes is kept to a minimum. The treated waste gets unloaded by semi-automatic cart dumpers into the primary shredder, and if sharps are treated, through the specially designed sharps shredder to provide the waste unrecognizable. Shredded waste can then be automatically transferred with an auger or conveyor to the compactor/container, if desired.


The proven design of this autoclave has pre- and post-vacuum cycles in a 100 psig rated pressure vessel. The control system monitors all main processing parameters including time, temperature and pressure to help ensure that the guidelines regarding the processing of infectious biomedical waste are met or exceeded. The main features are:
 
  • Units of various sizes for different size hospitals (1-6 cart units constructed of stainless steel);
     
  • PLC system providing precise and safe monitoring and control of operational parameters;
     
  • Quick-opening hydraulic door unit with locking ring;
     
  • Liquid ring vacuum pump designed for high-vacuum operation;
     
  • Temperature probe located in exit drain to ensure accurate temperature reading;
     
  • Unique condenser that removes excess moisture for less weight at time of disposal;
     
  • Internal track to facilitate cart loading;
     
  • Built for safety according to spe-cifications of ASME;
     
  • Loading ramp of lift table; and
     
  • External insulation with stainless steel or aluminium exterior wrap.
     

Contact: George K. Moss Co. Inc., P.O. Box 380156, Birmingham, AL - 35238, Alabama, United States of America. Tel: +1 (205) 408 2929; Fax: +1 (205) 408 4337


Website: www.gkmoss.com


Microwave treatment for infectious waste

Medister units, supplied by Meteka of Austria, use microwave process for the decontamination of infectious waste. The Medister models 10, 60 and 160 differ in waste processing capacity 6, 30 and 60 litres/cycle, respectively and allow different types of infectious waste to be disinfected. The equipment is efficient in eliminating Bacillus stearothermophilus spores to a minimum level of 6 log10. Depending on the model, the units generate a temperature of 110, 121 or 134C. One cycle of operation takes 45 minutes.


The model Medister 360 is used to sterilize highly infectious material in situations where perfect destruction of the biological agent is critical, such as waste from research laboratories that work with genetically modified organisms.
Meteka also manufactures a mobile microwave unit, which consists of three Medister 160 waste disinfection devices. Within an 8 hour shift, the unit can disinfect 36 Meditainer waste containers (2,160 l). Medister HF is another waste sterilization unit that operates with domestic service water transformed into steam using microwave.


Contact: Meteka, Burgasse 108, 8750 Judenburg, Austria. Fax: +43 (3572) 851666


E-mail: info@meteka.com


Website: www.meteka.com

PERSISTENT ORGANIC POLLUTANTS

Process for PCB dehalogenation

The CDP Process from the Italian company Sea Marconi Technologies is a safe technology for the on-site decontamination of transformers, dehalogenation of PCBs in insulating mineral oils, and recovery and No PCB re-classification (IEC 61619-1997 standard) of machinery and oil (IEC 60422 standard). The process also decontaminates metallic parts and solid insulation with an operative efficiency of up to 99 per cent. The PCBs dehalogenation and oil decontamination processes are carried out using the Decontamination Mobile Unit (DMU), which is a multi-function and mobile machine capable of treating from 500 to 5,000 litres/hour.


The modular, flexible and compact DMUs can handle different operational scenarios unmanned, offering protection against intrusion, spills and accidental emissions. They are intrinsically safe and eliminate risks of explosions or fires, and offer continuous operation with back-up of 4-8 hours. The CDP process allows optimum use of available resources in terms of cost-benefit and cost-effect.


Contact: Sea Marconi Technologies s.a.s, Via Crimea 4, 10097 Collegno, Torino, Italy. Tel: +39 (11) 4031 473; Fax: +39 (11) 4031 384


E-mail: info@seamarconi.it


Website: www.seamarconi.com

Catalytic decomposer of flue gas dioxins

Toyo Engineering Corp. of Japan, offers tunkey catalytic decomposer system for reduction of dioxins in flue gas into harmless substances such as water and carbon dioxide. The offer covers engineering work including layout planning, design, procurement and construction. The construction period is short and the compact system can be installed with most existing incinerators.


The decomposer system employs a titanium-vanadium catalyst, which offers high dioxins decomposition performance at lower temperature range of 180-200C, and a service life of 3-10 years, depending on the usage. As the catalyst does not adsorb dioxins but decomposes them, no secondary treatment is required. It can be used to remove a high volume of dioxins, and is resistant to SOx and alkali metals. By injecting a reducing agent such as ammonia, de-NOx operation can be carried out simultaneously.


Contact: Toyo Engineering Corporation, 7-1, 7-chome, Honcho, Funabashi, Chiba 273-0005, Japan. Tel: +81 (47) 422 81 23; Fax: +81 (47) 422 8145.


Website: www.nett21.gec.jp

Simultaneous soil Cd and PCB decontamination

Researchers from McGill University, Quebec, Canada, have investigated the simultaneous desorption of polychlorinated biphenyls (PCBs) and cadmium (Cd) from contaminated soil using a surfactant/ligand solution. The surfactant/ligand solutions used were combinations of a non-ionic surfactant polyethylene oxide (PEO) of chain length 7.5 (Triton X-114), 9.5 (Triton X-100), 30 (Triton X-305), or 40 units (Triton X-405), and iodide. Triplicate 1 g samples of soil were equilibrated during 24 hours with 15 ml of the surfactant/ligand solution, at 0.025 or 0.50 and 0.0, 0.168, or 0.336 mol l-1, respectively. The supernatant fraction was then separated from the particulates by centrifugation and analysed for Cd to determine Cd desorption efficiency. Following five consecutive washings, the treated soil samples were analysed for PCB content.


Desorption of Cd increased with both increasing ligand concentration as well as decreasing surfactant chain length and concentration. The maximum Cd desorption efficiency (61 per cent), was obtained with Triton X-100 at 0.025 mol l-1, in the presence of idodide at 0.336 mol l-1. Following five successive washings, virtually quantitative PCB desorption (below detectable limits for tetra-, penta- and hexachloro biphenyls) had been achieved with most surfactant/ligand combinations. Maximum desorption efficiency was achieved using either shorter chain length surfactant (n = 7.5 / 9.5) in combination with a higher ligand concentration, or using longer chain length surfactants (n = 30 and 40) with a lower ligand concentration.


The research thus established that heavy metals and PCBs could be desorbed simultaneously from contaminated soil with the same washing reagents, namely a surfactant-ligand combination. The optimum surfactant-ligand combination for the simultaneous desorption of both heavy metals and PCBs is a short chain length (n = 7.5 or 9.5) surfactant at low concentration admixed with 0.336 mol l-1 iodide.


Website: www.dekker.com

Dry-type dioxin removing unit

The Mitsui Mining Co. of Japan has introduced a dry type dioxin removal unit that uses activated coke (AC) to remove dioxins, volatile organic substances, heavy metals (such as mercury) and cyanides from the exhaust gas of incineration facilities. A demonstration and verification test conducted by Japan Environmental Sanitation Centre has verified the units performance in accordance with environmental regulations. The processing systems, which will vary depending on the requirements, are:
 
  • AC on moving bed system (circulating type) Contact processing with exhaust gas is performed while AC in the adsorber is in circulation. This system is suitable for an incineration facility that has large gas volumes and requires at least 99 per cent dioxin removal. Along with dioxins, the system also removes dust in the exhaust gas. Denitrification is allowed by blowing ammonia before introduction of the exhaust gas. Reheating is not needed since the system can work with exhaust gas temperature of 150-200C.
     
  • AC on moving floor system (circulation type) + regenerator AC and dust laden with dioxins on the moving floor are heated in the absence oxygen. Dioxins are adsorbed (at least 99.9 per cent), decomposed and rendered harmless. This system is economical since AC can be recycled.
     
  • AC on fixed bed system Exhaust gas passes through the fixed AC layer for processing. As several modular adsorption tower units in combination perform the exhaust gas treatment, this system is suitable for small incineration facilities that have a low gas volume. The unit is compact since it does not need circulation equipment. Consumption of AC is low and operation can be performed for a long time without refill. Since the dust deposited in the AC layer is periodically removed, pressure in the system is kept stable even through long operations.

Contact: Mitsui Mining Co. Ltd., 3-3, Toyosu 3-chome, Koto-ku, Tokyo 135-6007, Japan. Tel: +81 (3) 5560 2902; Fax: +81 (3) 5560 2913


Website: www.nett21.gec.jp   


Absorbent for removal of dioxin

Among the methods used for dioxin removal from incinerator exhaust gas, absorbent and catalyst technologies are the two most commonly used ones. While the equipment and technology for absorbent method are fairly simple, treatment of the spent absorbent containing dioxin is an issue. Research Institute of Industrial Science and Technology (RIST), Republic of Korea, has developed a cheap absorbent for dioxins from incinerator gas discharges and the related technology for their safe removal via a dust collector.
The high price of activated carbon, the most commonly used absorbent, makes absorption method comparatively expensive. The RIST team has developed a very efficient absorbent by utilizing the abundant and cheap powder cokes found in every steel mill. Field tests with incinerator exhaust gases have established the efficacy of the absorbent, and commercial production of the absorbent will start soon.


Contact: Mr. Gyeong Tae-Kim, Research Institute of In-dustrial Science & Technology, San-32, Hyoja-dong, Nam-gu, Pohang 790-600, Republic of Korea. Tel: +82 (54) 279 6544; Fax: +82 (54) 279 6099.


Website: www.rist.re.kr

CFC method turns asbestos into a harmless powder

Currently, breaking down asbestos is a costly process that require a large amount of electricity to heat the material to about 1,000C. A research team led by Dr. Akira Kojima, a materials engineering professor at Gunma National College of Technology, Japan, has come up with a method of reducing cancer-causing asbestos into harmless dust. The process uses chlorofluorocarbons (CFCs), a catalyst group linked to the destruction of the ozone layer. By-products, such as calcium fluoride and calcium oxide, generated by decomposed CFCs, are mixed with fibrous asbestos, and the mixture is heated to 700C. The chemical reaction that occurs converts the asbestos from fibrous material into a harmless powder. The patented process uses cheaper fuels, such as kerosene, instead of electricity. Dr. Kojimas method could lead to a cheaper and safer alternative to burying asbestos by detoxifying the material.


Website: www.asahi.com

System for continuous dioxin monitoring

The DioxinMonitoringSystem, from MonitoringSystems GmbH, Austria, is designed for the round-the-clock monitoring of dioxin emissions. The measurements are done according EN 1948 and EPA method 25. The correlation of long-time dioxin values (e.g. mean value of a month) to 6 hour mean values can be easily done in this system. The equipment can monitor all types of flue gases and exhaust gases, with the option to change the the technical application parameters in a wide range.


Dioxin Monitoring System consists of three main parts the filter unit, the sampling unit and the control unit. Each of these units is selected and adapted for each specific application. Since the system uses the dilution method and a special rinsing technique, the same device is useable in clean as well as raw flue gas. Measurement interval can be adjusted between 2 hours (0.01 - 100 ng TE/m) to 6 weeks (0.0001 - 10 ng TE/m). The two sampling probes and the Filter Unit cartridge, which is changed in regular intervals, are both made of titanium.


Contact: MonitoringSystems GmbH, Schloss 2, A-2542 Kottingbrunn, Austria. Tel: +43 (664) 2527239


E-mail: office@dioxinmonitoring.com


Website: www.dioxinmonitoring.com

INDUSTRIAL WASTEWATER

Wet air oxidation

Canadas Kenox Technology Corporation has developed a patented process that operates under high temperature (205-260C) and pressure (450-1,200 psi) to oxidize organic as well as oxidizable inorganic materials in aqueous solution to low molecular weight compounds. In the Wet Air Oxidation (WAO) process, the strong driving force for oxidation is provided by both enhanced oxygen solubility at high temperatures and by maximum oxygen transfer in the liquid medium using a built-in static mixer and recycle concept. This results in effective performance at less severe operating conditions and in capital, operating as well as maintenance cost savings.


The Kenox WAO oxidizes organic pollutants to carboxylic acids, carbon dioxide and water, and nitrogen, sulphur and phosphorous containing compounds to nitrogen, sulphuric and phosphoric salts. Inorganic sulphides are oxidized to sulphate. The process can be used to treat a wide range of industrial effluent streams and sludge containing soluble or suspended oxidizable substances.
Plant raw waste transferred to the feed tank is mixed and adjusted for required pH. A variable speed high-pressure pump increases the pressure and regulates the flow rate of the mixture to the system. The temperature of the pressurized feed is increased to reaction temperature. The pressurized high-temperature waste feed enters the reactor system where oxygen supplied from the air compressor reacts with the oxidizable materials of the waste to form by-products of low molecular weight that are subsequently oxidized to carbon dioxide and water. Spent air from the reactors top combined with oxidized liquid purged from the reactor circulation piping, is returned to the feed/affluent exchanger to preheat the waste feed. Non-condensable gases from the liquid-vapour separator are vented directly to atmosphere or scrubbed if necessary. The oxidized effluent is biodegradable, while metals are recovered by precipitation or filtration. The computerized process control system continuously monitors key operating parameters and automatically responds to different waste conditions.


Contact: Kenox Technology Corporation, 177 Forsythe Street, Oakville, Ontario L6K 3K4, Canada. Tel: +1 (905) 845 83 23; Fax: +1 (905) 845 48 08


E-mail: ljvan@kenoxtech.com


Website: www.kenoxtech.com

Dual-stage membrane bioreactor

PCI Membrane Systems Inc., the United States, has brought out an innovative dual-stage membrane bioreactor (MBR) for advanced treatment of industrial wastewater. The equipment delivers a higher quality effluent in less space and with lower operating costs than are normally associated with conventional activated sludge processing system. The dual-stage MBR system is a complete and continuous process that accepts wastewater with high loadings of BOD, suspended solids and other contaminants, and yields an effluent that is suitable for direct discharge to surface water bodies and low-grade re-use applications such as vehicle washing.


In the new system, the biological treatment portion of the process is kept separate from the membrane filtration stage. Each stage of the process can then be operated at its optimum condition. High-efficiency Sanitaire diffused aeration technology is incorporated into the biological treatment stage of the MBR system. Since membrane filtration is used instead of gravity settling for separation of solids, the level of mixed liquor suspended solids in the system can be a high 10,000-12,000 mg/l. This higher concentration of biomass provides resilience to changes in influent quality and also greatly reduces the overall plant footprint required. Importantly, it also reduces the amount of waste sludge that is produced.


In the membrane filtration stage of the process, the porous polyethersulphone membranes operate in the ultrafiltration spectrum, with a pore size of 0.2 m, to provide effluent of a very high quality. The MBR has been proven in multiple pilot-scale performance trials conducted on mu- nicipal and industrial waste streams.


Contact: PCI Membrane Systems, Inc., 1615 State Route 131, Milford, OH 45150, Ohio, United States of America. Tel: +1 (513) 575 3500; Fax: +1 (513) 575 7393.


Website: www.news.thomasnet.com   


Economic removal of copper from industrial wastewater

In Pakistan, a joint research by the Institute of Environmental Sciences and Engineering of National University of Science and Technology, the University of Agriculture, and NEAP-SP under the Ministry of Environment has investigated the removal of heavy metals from electroplating wastewater using economical materials. Adsorption on sand was examined as a cost-effective and simple treatment procedure for the removal of heavy metals. Adsorption is a preferred method for removal of heavy metals, as it is operationally simple and can adapt to changing waste-water flow rates and compositions.


Solutions of varying concentrations of Cu (25-100 ppm) were prepared and passed through sand column. Leachate samples were analysed for concentration of these elements using an atomic absorption spectrophotometer. This method of heavy metals removal proved highly effective, as removal efficiency increased with increasing pH and decreased with increasing metals concentration. The removal efficiency for Cu was quite high, ranging from 97 to 70 per cent. As higher pH results in the precipitation instead of permanent adsorption of Cu, the influent solution needs to be acidified prior to treatment. Sand has shown very high adsorption capacities and can be successfully be used for treatment of electroplating wastewater. Since this method is low in capital cost and high in efficiency, its use is feasible in developing countries.


Website: www.ejeafche.uvigo.es

Oxygen-activated sludge process

The OASES process, developed by Kruger Inc., the United States, re-sembles a conventional activated sludge treatment plant. The major components common to both processes are a reactor basin where aeration/oxygenation of mixed liquor occurs, a clarifier for settling the mixed liquor and a pumping system for return sludge. The distinguishing feature of the OASES process is that the toxic reactors are covered to introduce high purity oxygen gas into the reactor to increase the oxygen transfer capability. This allows the aerobic bacteria to consume the organic pollutants in the wastewater at a faster rate. In comparison with systems that provide oxygen transfer from air, OASES systems allow larger quantities of wastewater to be treated in smaller reactor basins. The OASES process is used for secondary treatment of industrial and municipal wastewater.


The system uses Biostyr biological aerated filter to combine in a single structure a biological reactor for pollution reduction and an effective filtration method. Biostyr achieves a wide range of effluent performance ranging from carbon (both COD and BOD) reduction to full nitrification and de-nitrification with minimization of suspended solids. The process is able to operate at such high removal rates that a footprint as small as 10-15 per cent of the more conventional schemes can be adopted. The fully enclosed reactor also eliminates odour issues common with other technologies.


Contact: Kruger Inc., 401 Harrison Oaks Boulevard, Suit 100, Cary, NC 27513, United States of America. Tel: +1 (919) 677 8310; Fax: +1 (919) 677 0082.


Website: www.krugerusa.com

Recycle system for tetramethyl ammonium hydroxide

Ecocycle Corporation of Japan has developed a new recycling system for tetramethyl ammonium hydroxide (TMAH). TMAH is widely used as a photoresist developer in the semiconductor and liquid crystal display manufacturing industry. TMAH by-products are ammonia compounds, and therefore effluent treatment is essential before its discharge. The recycling system is based on ion-exchange technology and recovers more than 90 per cent of pure TMAH, besides reducing industry waste solutions quantity to about one-sixth.


Contact: Ecocycle corporation, 694-2, Akada, Toyama, Japan 939-8064. Tel: +81 (76) 420 3122; Fax: +81 (76) 420 3161


E-mail: information@ecocycle.co.jp


Website: www.ecocycle.co.jp

Modular ammonia treatment system

USFilter, a Siemens Group Industrial Solutions and Services company, based in the United States, has developed an ammonia treatment system that removes dissolved ammonia from wastewater in the semiconductor industry. The modular system reduces ammonia concentrations to below 20 mg/l, while totally containing and eliminating air emissions. The system has been designed to treat 600 m3 per day of industrial wastewater containing up to 10,000 mg/l of dissolved ammonia. Treatment capacity can be increased by adding modules that treat 80 m3 per day. The ammonia is concentrated as 30-40 per cent ammonium sulphate solution, which may be stored for periodic disposal off-site or further treated for use as fertilizer. Standby modules provide complete system redundancy.


Website: www.noticias.info

High-performance compact reactor

In the Republic of Korea, Sambo EN-Tec Co., which specializes in the treatment of industrial wastewater, has extensively tested and installed in several locations a high performance biological treatment process. The HCR process, developed at the Technical University of Clausthal in Germany, is an aerobic, biological process combining a loop reactor and a special two-phase jet nozzle. The loop-type bubble column design ensures optimum material transport, while the design and arrangement of the two-phase jet promotes the necessary dispersion of biomass and air within the wastewater.


HCR unit is a tower type reactor for wastewater treatment and works according to the activated sludge principle. A typical unit consists of a cylindrical vessel, a vertical draft tube open at both ends, and a two-phase jet projecting into the tube. In the first air-intake step, when mixed liquor is fed into the draft tube via the two-phase jet, its increased velocity creates a vacuum sucks in the outside air through the internal pipe. The jet from the nozzle breaks up the bacterial aggregations and the induced air very finely, in a step called primary dispersion, to create ultrafine bubbles. In the secondary dispersion step, the liquid flow is reversed, from the bottom to the top of the reactor, and a portion of the mixed liquor is sucked back. Air bubbles in this liquor get dispersed again into fine ones, thus maximizing the mass transfer of oxygen. The liquor remaining is discharged from the reactor into the clarifier.


HCR process offers substantial reduction in investment and operating costs. Surplus sludge production is reduced by more than 40 per cent. HCR can efficiently treat even toxic contaminants such as phenol, furfural, formaldehyde and resin acids.


Website: www.samboet.com

Removal of organic pollutants from textile dyeing wastewater

As the metal contaminants in textile dyeing effluent are present in complex form, conventional precipitation and/or reduction methods cannot effectively remove them, while the colours are poorly removed. A new treatment process developed by the Centre for Applied Energy Research, University of Kentucky, the United States, removes colours and heavy-metal pollutants at the same time. Tests with dyeing wastewaters have demonstrated that this new treatment process can remove 90-99 per cent of the colours/dyes. They also showed the linear relationship between colour content reduction and toxic metals removal. Treated effluents that had low colour content also had low copper concentration. The treatment cost worked out to less than US$ 0.50 per about 4,000 litres.


The innovative process consists of three components: hydrophobic precipitation of dyes using proprietary chemicals; self-association of the colloid particles to form polymer-like networking aggregates; and separation of the aggregates from water. The benefits that the new process promises include:
 
  • More cost-effective;
     
  • Much shorter retention time;
     
  • Lower energy consumption;
     
  • High quality water; and
     
  • No sludge disposal problems.
     

Contact: Dr. B.K. Parekh, Centre for Applied Energy Research, University of Kentucky, 2540 Research Park Drive, Lexington, KY 40511-8410, Kentucky, United States of America. Fax: +1 (859) 257 0302

E-mail: parekh@caer.uky.edu


Website: www.caer.uky.edu


Combined bio-nano technique for wastewater treatment

Sharp Corporation, Japan, has developed a novel method for treating semiconductor plant wastewater that combines its own micro-organism treatment technique with nanotechnology. Sharp claims that the hybrid approach can reduce nitrogen content in chip plant wastewater by 90 per cent without any sludge.


The technique uses Sharps proprietary treatment technique with micro-nano-bubble technology. Together, the method eliminates 90 per cent of nitrogen in wastewater, the dis- charge of which is linked to algae blooms in waterbodies.


The sludge-free technique cuts the production of solid wastes. Sharp would conduct demonstrations and install the wastewater technique in its manufacturing plants.


Website: www.eetimes.com

Bioconsortium for the treatment of metalworking fluids


A team of researchers at the Centre for Clean Water Technologies, the University of Nottingham, the United Kingdom, has studied a bioconsortium for the treatment of nanofiltered permeates in effluent fluids from the metalworking industry.


Conventional treatment methods of waste metalworking fluids produce an aqueous phase containing toxic components and a high COD. The researcher team sought a biological solution to further reduce both the effluent COD and toxicity, and came up a method to develop a bioconsortium from microbes found in the waste metalworking fluid itself. The team, using flask tests, showed the feasibility of using the metalworking fluids indigenous microbial community for degrading the nanofiltration permeate of the metalworking fluid. A suspended bioreactor allowed the development of a better-adapted consortium. A fixed-bed bioreactor inoculated with the developed bioconsortium was set up and run for 8 months to test the bioconsortiums robustness as well as to optimize the biological process. The process using the bioconsortium developed achieved a 90 per cent reduction in the original nanofiltration COD level.


Website: www.ingentaconnect.com

AIR POLLUTION CONTROL

SCR for advanced NOx control

Industrial and Power Systems and Services Company of Toshiba Corporation, Japan, is offering a new selective catalytic reduction (SCR) unit with advanced control methods for removal of nitrogen oxides (NOx). The NOx control loop is known for its difficulties, as NOx emissions fluctuate according to process parameters.


The Toshiba SCR system reduces this by 75 per cent. Excessive ammonia consumption is also an issue involved in keeping NOx emission under a set value. A 10 per cent reduction in the consumption of ammonia, as compared with similar systems, is another benefit of this SCR system. It also has short set-up time and lower installation cost.


Contact: Industrial and Power Systems & Services Company, Toshiba Corporation, 1-1 Shibaura 1-chome, Minato-ku, Tokyo 105-8001, Japan.


Website: www.Toshiba.co.jp 

Capturing carbon dioxide

Researchers from the University of California, Santa Cruz (UCSC), and Lawrence Livermore National Laboratory (LLNL) have invented a new method for controlling the emission of carbon dioxide (CO2) from power plants. The technique mimics natural weathering process to convert CO2 into soluble compounds that can be disposed of in the ocean.


Accelerated Weathering of Limestone, the new carbon sequestration method co-invented by Dr. Greg Rau of UCSC and Dr. Ken Caldeira of LLNL, involves reacting CO2 in the stream of waste gas from a power plant with water and limestone (calcium carbonate) or other carbonate compounds. When CO2 dissolves in water, the water becomes acidic, which makes it corrosive to limestone. Dissolution of limestone by carbonated water generates soluble bicarbonate ions, the process by which rainwater erodes limestone cliffs and creates limestone caves and sinkholes. Because the waste-gas stream of a power plant has a high carbon dioxide concentration, water acidification will be rapid and will lead to an efficient dissolution of the limestone, Dr. Rau said.


In a model system devised by Dr. Rau and Dr. Caldeira, waste gases bubble up through a slurry of water and limestone particles. Water is constantly sprinkled onto the slurry, and wastewater with bicarbonates is pumped out. The bicarbonates in the wastewater are in equilibrium with dissolved CO2. Direct contact with ambient air would shift the equilibrium, resulting in the escape of CO2 back into the atmosphere. To prevent this, the wastewater must be released below the ocean surface, where it can mix and be diluted with ocean water before coming into contact with the atmosphere.


Website: www.e4engineering.com

Desulphurization systems for flue gas

Babcock-Hitachi of Japan offers two flue gas desulphurization (FGD) systems based on limestone-gypsum method. The companys FGD has a spray tower for absorber, which has a simple structure with a few internal components that eliminates scaling and provides a high degree of reliability. In addition to high level of desulphurization, the system efficiently removes even fine dust when slurry is sprayed in the spray tower. This precludes the need to install a wet electric precipitator at the downstream of the SOx removal system. Efficient liquid-vapour contact of particulate slurry and flue gas ensures low pressure loss. The oxidation agitator uses a small amount of power to create tiny air bubbles from oxidized air to fully oxidize absorbed SO2 to high-purity gypsum.


Babcock-Hitachis simplified FGD is an economical alternative to its high-efficiency FGD. This system employs a horizontal flow absorber (horizontal spray method) that desulphurizes in horizontal gas flow section, coming into contact with limestone droplets. This absorber can be installed or retrofitted easily between the flue gas ducts. It achieves 90 per cent SO2 removal efficiency.


Contact: Babcock-Hitachi, World Trade Centre Building, 4-1, Hamamatsu-co 2-chome, Minato-ku, Tokyo 105-6107, Japan. Tel: +81 (3) 5400 2416; Fax: +81 (3) 5400 2460.


Website: www.bhk.co.jp

Customized process for acid gas removal

The global chemicals giant BASF offers customized solutions based on its proven gas purification technology. The aMDEA or activated ethyldiethanolamine process is for removal of acid gases like hydrogen sulfide and carbon dioxide in gas purification plants mainly in natural gas, synthesis gas and ammonia plants besides for other applications such as in iron ore reduction gases. The technology is claimed to be highly efficient, very flexible, environmentally friendly and low in capital expenditure.


The aMDEA solvents employed for sour gas treatment are not corrosive, which permits high sour gas loading and therefore reduced solvent circulation rates. This, together with the low energy demand of the process, keeps operating and maintenance costs low. BASF offers a full range of services such as start-up assistance, process simulation, operator training, laboratory service, troubleshooting and plant optimization.


Contact: East Asia Regional Headquarters, BASF Limited, 45/F, Jardine House, No. 1 Connaught Place, Central Hong Kong, China. Tel: +852 2731 01 11; Fax: +852 27 34 9631.


Website: www.basf.de

SCR catalysts

Selective catalytic reduction (SCR) systems are very effective at cutting NOx emissions from power generating equipment, which includes gas turbines, utility/industrial boilers and reciprocating engines. These systems use catalysts to promote the reaction between flue gas NOx and a reagent, e.g. ammonia, injected into the flue gas stream. Engelhard Corporation, the United States, provides innovative catalysts for use in these systems. Each of these SCR catalysts selectively converts NOx into nitrogen and water, thereby reducing NOx emissions by up to 99 per cent.


The products consist of porous ceramic, honeycomb substrates that have been coated with either a vanadium-titanium (VNX) or zeolite (ZNX) catalyst. The catalysts are formulated to withstand high operating temperatures, and the ceramic substrates can withstand thermal shock associated with rapid start-ups, shutdowns and turbine trips. This means that there are no restrictions on how fast a turbine can be brought up to full-load operation.


NOXCat ETZ, a related catalyst product based on the ZNX catalyst technology, includes many features that make it ideal for use in simple cycle power-generating turbines.


Contact: Engelhard Corporation, 101 Wood Av., Iselin, NJ 08830, United States of America. Tel: +1 (732) 205 5000


E-mail: info@engelhard.com


Website: www.engelhard.com

Gas treatment systems

Cansolv Technologies Inc., Canada, offers different types of CANSOLV gas treatment systems. Its AquaNOx process is intended for treating gases containing less than 1,000 ppm of SOx, or in situations where caustic scrubbing is economical. Both SOx and NOx are removed to less than 10 ppm. The process uses a proprietary aqueous regenerable solvent and a high efficiency absorber column.


The CO2 Capture System employs an improved CO2 absorbent, which addresses deficiencies of current technologies. It can also be used as a pre-treatment to flue gases from sulphurous fuels such as petroleum coke, coal and heavy liquid fuels.


The SO2 Scrubbing System is a regenerable SO2 scrubbing process. This patented technology uses an aqueous amine solution to achieve high-efficiency selective absorption of SO2 from a large variety of gas streams. The scrubbing by-product is pure, water-saturated SO2 gas recovered by steam stripping. The regenerable absorbent eliminates the high cost of consumable absorbents, while its high capacity and selectivity reduce capital costs.


Contact: Cansolv Technologies Inc., 8475, Avenue Christophe-Colomb, Suite 2000, Montreal, Quebec H2M 2N9, Canada. Tel: +1 (514) 38244 11; Fax: +1 (514) 3825363


E-mail: mail@cansolv.com


Website: www.cansolv.com

Flue gas SO2 removal systems

The Mitsui-GE systems for flue gas SO2 removal, developed by Mitsui Mining Co. Ltd. of Japan in technical collaboration with General Electric of the United States, employs limestone or slaked lime as absorbent and gypsum is produced as the by-product. The treatment method, for instance, in a coal-fired thermal power plant could be the soot mixing method or soot separating one. The soot mixing method is an economical process for dust and SO2 removal. It employs a small amount of Na catalyst developed by Mitsui Mining to rid undesirable effects of flue gas impurities on SO2 removal performance. The soot separating method employs a pre-scrubber to remove impurities in flue gas and ensure stable SO2 removal and high quality of gypsum. The pre-scrubber has low gas pressure loss and high removal efficiency. It has two kinds of spray types forward flow and backward flow which helps treat large volumes of flue gas within one tower.


Contact: Mitsui Mining Co. Ltd., 3-3, Toyosu 3-chome, Koto-ku, Tokyo 135-6007, Japan. Tel: +81 (3) 5560 2902; Fax: +81 (3) 5560 2913.


Website: www.nett21.gec.jp 

DeNOx-SCR catalyst for diesel engines

Haldor Topse A/S, Denmark, has developed an SCR catalyst specific to automotive applications. The catalyst design is based on a unique corrugated ceramic structure that supports different catalytically active metal oxides. It combines the high mechanical strength of wash-coated cordierite and the high activity of extruded catalysts, with the entire channel wall material of the carrier being catalytically active. A typical catalyst volume of 2.5 in relation to the engine cylinder volume gives 85 per cent NOx and hydrocarbon removal. Particulate matter is reduced by 50 per cent.


Contact: Haldor Topse A/S, P.O. Box 213, Nymllevej 55, DK-2800 Lyngby, Denmark. Fax: +45 4527 2999.


Website: www.haldortopsoe.com


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