newsletter newsletter sludge incineration technology

Newsletter - October 2010 1

NEWSLETTER NEWSLETTER NEWSLETTER NEWSLETTER October 2010

Sludge Incineration TechnologySludge Incineration TechnologySludge Incineration TechnologySludge Incineration Technology

Waste water treatment and sludge treatment are both key technologies required for a state of the art waste disposal. Sludge is commonly generated as part of biological waste water treatment, either from urban and/or industrial source. Sludge produced by waste water treatment facilities is usually highly contaminated and water content is normally very high. Improper treatment or land fill of sludge creates a massive problem for the environment and therefore need to be addressed in a very professional way. Sludge typically originates from:

Water sedimentation tank/concentration pound Industrial or communal waste treatment Pound/tank bottom sludge Polluted soil by chemicals or oil

Sludge pre treatment and incineration is a well known technology and is part of a proper sewage handling and has become standard in developed countries. Sludge Pre Treatment: under this terminology we understand volume reduction, stabilization and detoxification of sludge in a multi stage process Sludge Incineration: After pre treatment sludge is usually incinerated in a continuous process with maximum heat recovery followed by a state of the art off gas treatment in order to meet governmental requirements. Ash Disposal: Following proven and validated incineration technology, ash from sludge incineration processes can be disposed in dedicated landfill areas in a controlled and environmentally compliant way. Generally sludge has a very wide range of contaminants and can be characterized as: Small particles, low density, high water content, hard to dehydrate with a high organic content, contains viruses and bacteria, parasites as well as heavy metals. Therefore, sludge treatment requires effectiveeffectiveeffectiveeffective treatment treatment treatment treatment methodmethodmethodmethod based on proven technologyproven technologyproven technologyproven technology!


Raschka Fluidized Bed IncineratorRaschka Fluidized Bed IncineratorRaschka Fluidized Bed IncineratorRaschka Fluidized Bed Incinerator

Typical Sludge Treatment MethodsTypical Sludge Treatment MethodsTypical Sludge Treatment MethodsTypical Sludge Treatment Methods Currently, there are 4 typical ways of how sludge is disposed:

2. Compost Generation Compost generation used to be a popular way for sludge disposal. The basic theory is to use aerobic microorganism to decompose kinds of organic oxides in sludge, turning it into humus which can easily be absorbed by plants.

But as people highly focused on green food and increasing awareness of soil pollution of contaminates like heavy metal, sludge compost generation is facing more limitation and critical requirements. It is also inconvenient and provides low performance when compared with regular fertilizer. Therefore this method is no longer popular.

3. Drying Sludge drying technology is using heat to sterilize the sludge and destroy its gel structure. The temperature reaches to 95℃ to kill the pathogen, and it can significantly reduce the volume and eliminate the odour.

But the process requires a lot of energy, is complicated, requires high investment and operational cost and will not reduce the volume completely. Further condensation and odour removal by evaporation will need to be carried out. Usually this is not a preferred option for final sludge treatment.

4. Incineration Sludge incineration is a high-temperature technology, with high-temperature combustion and excess air for complete oxidation, pyrolysis and destruction of all organic components and pathogens in the sludge.

A technology which provides a high throughput and requires a relatively small area and achieves a volume reduction over 90%, sludge incineration has been widely applied in western countries. It is considered the most efficient method for volume reduction in a stable and safe way. Usually dehydrated sludge will directly be sent into incinerator or alternatively will be dried before incineration.

The fluidized bed incinerator we recommended allows the sludge to be incinerated with dried or high water content up to 80%~85%. Auxiliary fuel is required when dealing with high moisture, proper process design and equipment selection must be made for entire incineration plant which includes heat recovery and off-gas treatment technology.

1. Landfill Landfill after dehydration is a common way because of cost reason. Sludge landfill in China has been the preferred “treatment” for a long time.

However, the water contend of dehydrated sludge is usually much higher than 30% and exceeds the regular landfill requirement. It needs further processing or special designed landfill plant which requires a fairly large area, at the same time it faces the problem of location selection, leaching of contaminated water with the risk of polluting the groundwater and managing such areas for a very long time provides an irresponsible hypothec for our next generation. Improper landfill may become the source of a secondary pollution.


Fluidized bed incineration is an ideal choice for its low-temp/low excess air requirement, high incineration efficiency, long gas holding time, even temperature distribution, excellent harmful components destruction capability, effective NOx/SOx/HCl generation control, economic operation, low maintenance and long life cycle! However, sludge incineration requires a relatively high initial investment and high operation cost. Advanced technology in a continuous process is also required for effective treatment of slag, ashes and off-gas which may contain heavy metal after sludge incineration.

Fluidized Bed Fluidized Bed Fluidized Bed Fluidized Bed IncinerationIncinerationIncinerationIncineration Process Description Process Description Process Description Process Description Sludge incinerator system includes: sludge feeding, sludge pre treatment, fluidized bed incinerator, recovery boiler, off gas treatment, ash & slag collection and conveying.

Sludge feeding system----feeding the sludge Due to the high water content (sludge from wastewater treatment plant is like liquid) a screw pump is used to feed to centrifuge for dehydration, after that, the sludge cake is like paste and can now be transferred by screw or belt conveyers.

Sludge pre-treatment system----to lower water content Water content level is the key element driving operation cost, higher water content means lower heat value with the result that incineration process needs more energy and obviously drives operation cost up. Regular sludge dehydration methods are: belt filter press, plate frame filter press and centrifuge. The free water content remains at about 80%-85% after physical dehydration, after that sludge can usually be sent to fluidized bed incinerator directly. Some of the heating energy required comes from recovered heat and will save a great deal of operation cost.

RaRaRaRaschka Fluidized Bed Incineratorschka Fluidized Bed Incineratorschka Fluidized Bed Incineratorschka Fluidized Bed Incinerator


Fluidized bed incinerator----the key equipment for sludge incineration The primary burner heats up the fluidized bed and sand (bed materials) to about

850~870℃, then the spreader distributes the sludge evenly into the fluidized bed. The fluidized bed incinerator is a brick lined steel casing with an inner refractory lining and an outer thermal insulation. The main sections are the conical lower part with the windbox, the nozzle bottom and fluidized bed area and the cylindrical upper part with the freeboard area. The nozzle bottom is a ceramic sandwich construction equipped with air nozzles made of heat resistant cast steel. The combustion air is blown by the combustion air blower into the combustion chamber that is connected to the windbox. From there the combustion air comes into the windbox below the nozzle bottom. During heating up of the incinerator the combustion air is heated up in the combustion chamber by means of the combustion chamber burner. Then the combustion air flows through the air nozzles in the nozzle bottom upwards and fluidizes the sand-layer above the nozzle bottom evenly. The freeboard area above the fluidized bed serves as post-combustion zone with long retention times of the flue gas and fly ash particles. The secondary wind is injected by suitable position and quantity depends on the combustion condition. So a perfect combustion is achieved, higher efficiency and lower NOx produced . If the sludge is defined as dangerous waste, then secondary combustion is

required to have gas being treated for at least 2 seconds at 1'100℃ to comply with Chinese environmental regulation of No. 2004-15.

Heat recovery boiler----to recover the heat coming from incineration Heat recovery boiler is to collect the incineration heat, and generate the steam. The special designed boiler is designed to deal with dust in flue gas. If the sludge is defined as dangerous waste, then the gas must rapidly be quenched when at 500-600℃ to avoid generation of dioxin, a requirement defined by Chinese environmental regulation No. 2004-15.

Flue gas treatment system---- to reach the emission standard The treatment system includes quench reduction of acid gases, removal of dust as well as NOx reduction. Emissions like nitrogen oxides, sulphur dioxide, acids, heavy metal, dust and dioxins will be controlled to full fill the emission standards required.

ChallengesChallengesChallengesChallenges in Sludge Incineration in Sludge Incineration in Sludge Incineration in Sludge Incineration Sludge incineration technology currently available in China still needs improvement. Government,

enterprises and other society resources need to support and cooperate in policy, technology and

funding to achieve an environmental friendly disposal of sludge.

Proper sludge water content levelling is the key element of operation cost optimisation.

Sludge handling/disposal includes pre-treatment, incineration, heat recovery and combustion

outcomes. These process steps must be properly designed and implemented during construction.

Acid off-gas, slag and fly ash after incineration must be well processed in order to comply with the

emission standards and regulation. This is a key technology as well.

Ash handling: the following options are possible and selection will depend on heavy metal content

− Directly to landfill or to be added to form green cement brick

− Landfill after adding heavy metal chelator Reliable design, products and construction are necessary for effective performance.


AdvantagesAdvantagesAdvantagesAdvantages when working with when working with when working with when working with Lonza EngineeringLonza EngineeringLonza EngineeringLonza Engineering

Lonza Engineering offers entire solutions, including initial research, process design, EPC/EPCM. We are committed to bring western proven advanced technology and make maximum domestic manufacturing to offer customer the best quality with the most economic price.

In sludge incineration, Lonza Engineering has successfully completed several projects, and we have established partnership agreement with European high tech companies in many kinds of aspects.

Sludge incineration is a chemical process, while Lonza has over 110 years chemical production experience, especially in process development, integration, process control and management.

Lonza Engineering has strong capability in process design, technology integration and global professional support.

Lonza Engineering and its partners have unique and reliable advanced technologies, especially in Europe, there are many successful projects that can be visited and studied.

Domestic partner Taihu Boiler has rich experience in equipment manufacturing and site installation which will drastically reduce the incineration system investment cost.

Sludge specification: Urban/Industrial Sludge (85% water content)

Annual operation hours: 8'000 hrs

Capability: 5 tons/hr

Service time: Since 1976

Chamber: 870℃，-3 mbar

Emission Standard: DIRECTIVE 2000/76/EC

LonzaLonzaLonzaLonza’s’s’s’s Sludge Incinerator in Switzerland Sludge Incinerator in Switzerland Sludge Incinerator in Switzerland Sludge Incinerator in Switzerland

Lonza Sludge Incinerator in VISP, SwitzerlandLonza Sludge Incinerator in VISP, SwitzerlandLonza Sludge Incinerator in VISP, SwitzerlandLonza Sludge Incinerator in VISP, Switzerland


Lonza Engineering and its partners Lonza Engineering and its partners Lonza Engineering and its partners Lonza Engineering and its partners

Lonza Engineering

Supply services of sludge incinerator system EPC/EPCM, process design, technology transfer, control system design and execution, installation management, QA/QC, commissioning and maintenance etc., to ensure system integration and performance to comply with Chinese laws and regulation.

Switzerland China

Dumag

Founded in 1930, own the top waste gas/waste liquid atomizing, thermal process techniques, supply core technology and equipment of industry burners and ultrasonic nozzles. The products can be used in industry incinerator, fluidized bed incinerator and municipal waste incineration plants.

Austria

Meidinger

Meidinger is one of the few companies who are certified for Zone 0 fan production. High quality and advanced fans are used to transfer combustible and poisonous gas in chemical, pharmaceutical, environmental and energy industry.

Switzerland

Raschka

Founded in 1946, specializes in fluidized bed technology, design and construct fluidized bed incinerators and waste heat steam boilers for power generation, energy recovery and environmental thermal disposal. Products can handle municipal/industry sludge, domestic waste, waste from slaughter house, biomass, ballast coal and residual waste from paper-, cellulose- and chemical industry.

Germany

Wehrle-

Werk

Founded in 1860, professional in heat recovery solution, strong capability and rich experience in energy and environmental protection industries.

Germany

Protego

Over 50 yeas of flame arrestor fabrication and testing. Offers professional industrial flame arrestors, valves and tank accessories with ATEX, RTN, WHG191 certificates.

Germany

Taihu Boiler Famous domestic boiler manufacturer, offers equipment localization design, fabricating and technology transfer.

China


In this context, Lonza In this context, Lonza In this context, Lonza In this context, Lonza EngineEngineEngineEngineering’s service could ering’s service could ering’s service could ering’s service could include:include:include:include:

EPC/EPCM contractor for entire sludge incineration system

Sludge incineration technology consultancy

Engineering and design support

Process analysis and optimization

Control system design and execution

Supply high-tech key products/parts/units/modules for sludge

incineration

Evaluation of technical solution for your specific sludge

incineration methods

Installation supervision, calibration and maintenance

Qualification and validation of sludge incinerators and relevant

process control system

Continuous improvement and optimization of existing systems

Please feel free to contact us in order to discuss your needs with

our expert team, we would be very happy to share our

experience in waste management and specifically in sludge

incineration

An extensive service list is available on our website:

http://www.lonza.com/engineering

Lonza Engineering LtdLonza Engineering LtdLonza Engineering LtdLonza Engineering Ltd

Lonza Engineering is a subsidiary of Lonza

Group Ltd and provides customer oriented

services with a professional, experienced and

highly motivated engineering team. We have

more than 15 years of successful project

management experience in China which

makes us a perfect partner for the chemical,

pharmaceutical and biopharmaceutical

industry. A broad range of services with a

project reference list underlining our

capabilities is available upon request.

Lonza Engineering Ltd. Basel, Switzerland,

created in August 2008, has founded a wholly

owned subsidiary called Lonza Guangzhou

Engineering & Consulting Co., Ltd.

Lonza Engineering has successfully managed

multiple and complex projects such as

continuous operating plants for the production

of food and feed additives as well as active

pharmaceutical ingredient plants including

waste gas and liquid waste treatment

facilities. The management team of the new

company consists of current Lonza

employees from Switzerland and China.

ContactsContactsContactsContacts

Lonza Engineering LtdLonza Engineering LtdLonza Engineering LtdLonza Engineering Ltd

Muenchensteinerstrasse 38, CH-4002 Basel,

Switzerland

Tel: +41 61 316 8606

Fax: +41 61 316 9606

Email: [email protected]

[email protected]

Website: http: //www.lonza.com/engineering

Lonza Guangzhou Engineering & Consulting Lonza Guangzhou Engineering & Consulting Lonza Guangzhou Engineering & Consulting Lonza Guangzhou Engineering & Consulting

Co. LtdCo. LtdCo. LtdCo. Ltd

68, Huanggedadao Bei, Nansha district,

Guangzhou, 511455, Guangdong Province,

China

Tel: +86 20 3497 1118

+86 20 3497 3888 ext. 2377

Fax: +86 20 3497 2288

Email: [email protected]

[email protected]

Website: http: //www.lonza.com/engineering

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