7th Global CemFuels Conference 2013
11- 14 March 2013
Image gallery for the 6th Global CemFuels Conference 2013
The Global CemFuels Conference and Exhibition 2013 has successfully taken place in Istanbul, Turkey, featuring two well-attended field trips to local alternative fuel-using cement plants, a major exhibition, 25 presentations, an impressive Gala Dinner, the Global CemFuels Awards and 150 delegates from 30 countries and lots of networking. The next Global CemFuels Conference will take place in Vienna in spring 2014.
What have dead dogs, lumps of concrete, bicycles, fishing nets and video tape all got in common? Read on to find out!
The 7th Global CemFuels Conference started with a visit by delegates to the Nuh Çimento plant, the largest cement plant in Turkey., which featured an RDF-handling plant built by Di Matteo as well as a sewage sludge processing plant supplied by Andritz. After a fantastic lunch at the plant, delegates subsequently enjoyed the welcome party back at the smart conference hotel, the Divan.
First day
Dirk Lechtenberg of MVW Lechtenberg opened the conference with an overview of alternative fuels use around the world. He pointed out that cement manufacturers don't use alternative fuels for the good of the environment, but rather for the good of their profitability: any environmental benefit is a welcome bonus. "If using alternative fuels was easy, everyone would be doing it," Dirk stated, before going on not only to enumerate the benefits of using alternative fuels (AF), but also the many problems that come with the use of AF. Dirk said that cement companies are progressively reorganising themselves to be able to process and use AF in large and economic quantities, so that waste management is part of their day-to-day business. Ultra-fine milling of alternative fuels has been tried in order to make previously unusable fuels burnable, but it is still uneconomic. External combustion chambers can also be used for hard-to-burn fuels, as can pyrolysis. Hydrothermal carbonisation can be used to upgrade high moisture fuels. Dirk urged his listeners to 'keep it simple!'
Kerem Ersen of the Turkish Cement Manufacturers Association, the TCMA, gave an update on developments in the Turkish cement industry. The TCMA was founded in 1957 and is fully linked with all significant national and regional cement bodies, and represents 68 cement plants throughout Turkey, of which 48 are integrated plants. Installed cement production capacity in 2012 was 108Mt. Turkey has a healthy level of exports to Russia, and has been busy supplying materials to Sochi for the Winter Olympic Games. Turkish cement consumption is expected to grow by 4-5% through 2013, while the situation on international markets, such as Iraq, Syria and the rest of the MENA, will be mixed. A major urban transformation project, to upgrade 8m housing units for seismic hazards, is set to underpin demand for cement in Turkey for the next 20 years.
Neville Roberts of Cemex next gave details of the AF strategy of Cemex, worldwide, via its company Cemex Energy Trading. Neville pointed out that Cemex uses more AF than any other global cement company, with a thermal substitution rate (TSR) of around 27%. By 2015, Cemex expects to have a TSR of above 35%. Neville reminded his audience that refuse-derived fuel (RDF) has a calorific content of below 15MJ/kg, whereas solid recovered fuel, SRF, has a calorific value of above 15MJ/kg. Over the years, Cemex has had to become expert in the preparation of AF, and concentrates on quality parameters such as particle size, low heating values, moisture content (either too high or too low) and critically, chlorine content. Neville Roberts stated that Cemex will consume around 2Mt of SRF in 2013. Cemex has achieved TSR on individual kilns of 60-80% for prolonged periods and with no significant reduction in production capacity (or even while managing to increase levels of production). Cemex has found that emissions levels are invariably improved when burning AF. Cemex has spent a great deal of time and effort in making sure that the local community is kept informed of developments whenever AF is used. Cemex also trades 4-6Mt of petcoke around the world. Cemex is now prepared to go out to help other cement companies to burn more AF around the world.
Hakan Gurdal of Akçansa, part of HeidelbergCement, pointed out that cement companies are changing themselves into energy transformation companies. Akçansa produced 9.4Mt of cement in 2012 with an EBITDA margin of around 20%. Hakan pointed out that although electricity demand is increasing at around 5% each year in Turkey, supply is keeping pace, so that price trends are not necessarily increasing upwards. At the same time, petcoke prices have not always increased, and for example have dropped from US$170/t to US$40/t over the last few years. Akçansa has installed a 16MW waste heat recovery (WHR) plant from Sinoma, with an investment of US$24m. He stated, "Never sign a contract on an FOB basis from China, insist on project managers that can speak English, and be as clear as possible at the tender specification stage." Hakan Gurdal also stated that Akçansa, like all cement companies, is directly exposed to market risks in electricity and fossil fuels. However, AF use reduces this price volatility while at the same time allowing substitution between different waste streams. The establishment of long-term contracts will be critical for the successful development of the AF industry in Turkey. The detection of bottlenecks in the sourcing-storage-processing chain, and the solution of these problems, is vital. Finally Mr Gurdal said that Recydia is an important supplier of SRF to Akçansa.
Steve Smith from Golder Associates spoke about the sourcing and production of alternative fuels, particularly through the symbiotic co-location of waste-producing industries and the cement industry. Steve stated that the introduction of the Landfill Directive across Europe has driven the development of the use of AF, including usage by the cement industry. He pointed out that the use of SRF from an SRF producer by a cement producer can lead to a heat and electricity supply agreement back to the SRF production facility. Steve gave as an example the Cemex Rugby Climafuel production facility, which required substantial investment but which has achieved a long-term quality supply of waste-derived fuel (WDF) for the cement plant at Rugby. However, Steve Smith also pointed out that lower-grade waste could be supplied to a waste-to-energy gasification plant which would then supply a calorie-rich syngas to the cement plant, similar to the process used at the Chiba plant in Japan which is used to supply a steel plant. Another example, the Greve WtE (waste to energy) plant in Italy used a pelleted RDF to produce syngas for a local cement plant, showing that it can be done.
Sanjay Jain of Holtec Consulting Private next spoke about the use - and potential future use - of AF in India. He pointed out that the Indian cement industry is the second largest in the world, with an installed capacity of over 330Mt of production, at over 100 cement plants, including the world's largest clinker production line at over 13,000t/day. Sanjay gave the results of a study looking at the barriers preventing the use of AF in India, since the TSR in India is currently lower than 1%. The five most attractive alternative fuels in India were hazardous wastes, RDF from municipal solid waste (MSW), biomass, industrial plastic waste and used tyres. Biomass and RDF are currently available in the largest tonnages. The total tonnage currently available of these five types of AF in India is already over 20Mt per year. However, AF is usually only available in small streams which are typically geographically scattered. 'Aggregators' are required to bring together the waste streams into economically efficient quantities. Biomass needs to be 'energy-densified' if it is to be economically transported any distance. Sanjay pointed out that trial runs and usage permissions are hard-won and can take a long time and a lot of effort to acquire. There is also intense competition for AF from energy-generating companies in India. Sanjay suggested the creation of a national database on the availability of wastes that could be used as fuel. Simplification of the permitting process and the passage of enabling policies to encourage the use of AF in India (not least of which is the creation of a national landfill tax) should be priorities for the legislators.
Matthias Mersmann of aixergee Process Optimisation started the second session at the conference, on combustion optimisation. He stated that there are three main factors that limit secondary fuel burning; fuel burn-out issues, product quality and plant stability. Matthias pointed out that the equipment at an AF-burning cement plant must be adapted as much as necessary but as little as possible. Secondary fuels are coarser, less homogeneous and usually have higher moisture contents, so that ignition is generally delayed, complex and fluctuating. The burning behaviour of individual components of an inhomogeneous AF must be carefully investigated to discover the point at which they give up their energy into the pyroprocess, in order to correctly model and optimise the burning of secondary fuels. Computational Particle Fluid Dynamics (CPFD) can be used to model the behaviour of particles at high concentrations in a gas stream.
Martin Demuth of the Messer Group, 'the largest owner-managed industrial gas company in the world,' stated that oxygen enrichment can help clinkerisation through the reduction of 'off-gas,' allowing an increase in the adiabatic flame temperature when using AF and enabling the use of higher amounts of AF. Messer proposes the use of oxygen to atomise liquid fuels - even waste-derived liquid fuels. This patented Oxipyr flame-in-flame technique speeds up the burn-out of co-fired solid fuels.
Bertrand Leroux of Air Liquide pointed out that oxygen is the 'useful' part of air when it comes to combustion, and that nitrogen is unhelpful - the higher the proportion of oxygen in the combustion gas, the more effective it will be. Oxygen cannot be increased in the flame air to above 28% for safety reasons according to Bertrand Leroux. Air Liquide supplies its own oxygen atomising lance, called Alwaste L. Bertrand mentioned the Eox on-site solution for 45-55t/day oxygen supply, producing low pressure-high purity oxygen at low capex and reduced opex. The Corali research furnace is being used to investigate the optimisation of oxygen enrichment in combustion processes. Oxygen preheating using waste heat is being considered for further process improvement.
Michail Akritopoulos of well-known combustion optimisation consultancy Cinar Ltd gave specific information on how to increase the thermal substitution rate of AF in calciners. Using mineral-interactive CFD, the entire gas-particle-fuel flow and interaction can be modelled in three dimensions. In general, the position of injection of fuels is critical, as is the proper mixing of fuels with process and combustion gas streams. This - it hardly needs to be said - is often easier said than done.
Peter Erbel of FLSmidth spoke about the Feedex overhead reclaimer for AF storage and reclaim. AF can be stored in cylindrical- or rectangular-cross section silos, each with different options for materials reclaim, such as screw bottom, push floor or via the Feedex system. Feedex is a storage and reclaim system in an enclosed box, or in more than one box to allow blending. The box is usually made of concrete, or steel for smaller units, and allows simultaneous feeding and extraction. The system eliminates bridging and clogging, complete discharge is ensured, it has low energy consumption and has easy maintenance and cleaning. The Feedex frame is suspended on hoisting chains inside the box and is powered by dust-proof motors: the scrapers move continuously to distribute the materials inside the box. Simultaneous intake and extraction is possible. The standard bunker size is 15m high, 5m wide and 30m in length, with a storage capacity of 1500m3. Extraction capacity is up to 300m3/hour.
Luigi Di Matteo of the eponymous company spoke about AF handling with the WeighTube tubular weigh feeder (incidentally seen the previous day in operation at the Nuh Çimento cement plant field trip). Luigi pointed out that harmonised guidelines have been introduced into Europe for proper and reliable use of AF, which are often used outside of Europe as well. The WeighTube system is a continuous gravimetric system - incorporating a section of a screw-fed dosing pipe that is isolated on load cells to give accurate and responsive dosing capabilities.
Gala Dinner and CemFuels Awards 2013
Delegates boarded buses to travel to the RMK Museum, where they could inspect pristine examples of all sorts of transport - including American 'muscle cars,' old-fashioned horse and carts and even a submarine. Serenaded by Turkish street-band Amesha Spenta, delegates enjoyed a sumptuous buffet while the Global CemFuels Awards were presented. The awards are nominated and voted on by participants in the global alternative fuels industry. AF supplier of the year was Sita UK Ltd, AF user of the year was Cemex, AF project of the year was the Akçansa Büyükçekmece burner modification by FCT, while a clearly-delighted Con Manias of FCT picked up the AF 'innovation of the year' award for FCT's lofting air technology. Global CemFuels 'Personality of the year' was deservedly awarded to Neville Roberts of Cemex.
Second day
Roman Eggert of Putzmeister Solid Pumps started off the second day of the conference by detailing the sludge-pumping capabilities of his company. Hydraulically-driven piston pumps can handle a broad variety of materials, including those with 'foreign particles.' Putzmeister is best-known for its concrete pumps, but its most widely used pump for the cement industry is the KOS (S-tube) hydraulically-driven double piston pump. A twin feeding screw can be used, with screws arranged in a self-cleaning fashion, in order to feed material to the pump. Receiving and blending silo systems can be supplied prior to the feeding screws. A lubricating fluid such as waste oil can be injected to reduce the pressure required for long-distance pumping, using a boundary layer injection system. An atomiser lance is used at the kiln to disperse the sludge prior to combustion.
Boris Sassenrath of Vecoplan FuelTrack spoke about a modular treatment concept for secondary fuel. A robust pre-shredder is the first step, followed by a re-shredder. An air-separator can then be used for sorting, while the VecoBelt enclosed pipe conveyor can be used for fuel transport. Boris mentioned that Gore textile can be used on piles of waste to allow moist air to escape, reducing the moisture content of the waste, while protecting the waste from moisture accumulation from rain. Ahmet Somer of Somer International, representative of Vecoplan in Turkey, gave details of a number of reference projects throughout the Turkish cement industry.
Jori Kaaresmaa of BMH Technology Oy of Finland spoke about the Tyrannosaurus brand of AF preparation equipment. The offered Tyrannosaurus shredder is a one-pass, low power consumption device with a MIPS, (massive impact protection system) to avoid damage to the shredding knives, capable of taking in practically all types of MSW (including dead dogs, lumps of concrete , bicycles and other undesirable ingredients) and producing a higher specification SRF. Other Tyrannosaurus equipment include feeders, fines screens, air classifiers, fine shredders, automatic storage systems and dosage and feeding systems, even to the flame. Jori suggested that all of the equipment, taken together, offers a seamless and well-integrated system for SRF production. He concluded that in the future, coal will be considered as an alternative fuel.
Luc Rieffel of Walter Materials handling/ATS Group spoke about his company's storage, handling and dosage systems for alternative solids fuels, including automatic crane systems, apron extractor, weigh belt feeder, tyre singulator and dosing system, and a well-engineered and robust pneumatic double valve airlock for dosing AF.
Michael Schick of FLSmidth Pfister spoke about dosing options for AF, particularly using the Pfister multifuel Rotor Weighfeeder. The principle of operation of the rotor weighfeeder means that the amount of AF that is about to be fed into the pyroprocess can be determined, allowing a pre-emptive and continuous control of dosage. Such a system is in use at the Akçansa Büyükçekmece plant, visited during the second field trip at the CemFuels conference.
Marcus Brew of Untha suggested that there are five main steps towards establishing a successful SRF plant; understanding your input material, product and market; understanding how plant design and equipment can improve your products; total preventative maintenance; measuring and driving improvements; achieve management buy-in. Marcus gave as an example an SRF preparation plant in the UK operated by Sita UK.
David Hooper next spoke on behalf of the Italy-based company Entsorga on the subject of mechanical and biological treatment - MBT. The mechanical pretreatment stage aims to prepare the input waste. The biological treatment stage harnesses the bio-energy within the organic fraction of the waste to trigger an aerobic fermentation that develops the heat to be used for waste drying. The further mechanical refinement of the product eliminates inerts, metals and undesirable plastics, thereby producing an SRF to high specifications. David pointed out that the composition of the waste will vary significantly from city to city, varying markedly, for example, between Istanbul and Ankara and from country to country, and not just in moisture content. David suggested that the net benefit from co-processing 1 tonne of SRF in a cement kiln and displacing an equivalent amount of coal will trigger a reduction of 558-620kg of CO2 emissions. Entsorga offers a number of different MBT solutions of differing levels of capital expenditure and sophistication.
Klaus Rupp of Schenck Process GmbH suggested that there are three golden rules for the design of AF systems: you should apply robust systems - despite the low density of the fuels - to ensure high availability; you should avoid bottlenecks - since AF tends towards bridging; you should allow for variations in bulk density and flowability of materials to ensure high flexibility in fuel usage. Klaus gave details of a number of successful AF reception, storage, feeding and dosing projects in Romania and Turkey. The company has effectively used shaftless screws for feeding of coarse AF, including shredded tyres.
Turgut Bayraktar, originally from Istanbul but here speaking on behalf of Hanson UK - part of the HeidelbergCement Group - spoke about his company's experience with AF preparation and usage. The company's target is to use 30% TSR by 2020. 30-40% of the production cost of cement in the UK is taken up with the cost of coal, so there is a strong impetus towards the use of AF. Hanson UK's TSR was 56% in 2012. Turgut said that the AF feeding system at the new Padeswood plant, a Flexowell system, was accidentally set on fire, leading to a £500,000 rebuild cost and a £250,000 fine from the UK Environment Agency. A 3t/hr double flap valve was a significant bottleneck and also caused a discontinuous feed, causing pressure pulses and upsetting the pyro system. The double flap was replaced with a continuous feed chute which can swing out of position and be isolated in case of a fire or other fault condition. Feeding systems were also unexpectedly damaged by 'out-of-spec' materials, such as fishing nets and video tape: this led to very significant accuracy problems in feed rate measurements. The use of shaftless screws has now avoided this problem.
Dirk Wissmann of Spectro Analytical Instruments spoke about the possibility of using XRF for the on-site measurement of elemental composition. This is crucial to ensure contractual compliance of AF deliveries, as well as to make sure that the delivery will not cause emissions and permitting problems. Dirk emphasised that sample preparation is essential for accuracy when using XRF. This is partly due to the fact that different elements can be detected only at different distances from the surface of the sample: lower atomic weight elements can be detected only from very shallow depths (in the order of a few tens of microns), whereas heavier elements (often of most interest in AF, such as mercury or cadmium) can be detected from deeper in the sample, for some elements up to two or three centimetres deep, due to matrix effects. However, Spectro uses its Turboquant algorithm to consider fundamental parameters for fluorescence and scattering to reduce matrix effects. This technique gives reasonable results, even for hard-to-measure AF.
Mark Kragting of Vandenbroek International spoke about the possibilities for using waste heat to dry waste-derived fuels using a co-current multi-section Vadeb MPS drum dryer. The product is kept at a fairly low temperature to avoid early ignition, despite being capable of using gas at up to 350°C from the clinker cooler. A very wide variety of waste-derived fuels can be dried in the drum dryer. Mark gave details of a Vadeb drum dryer installed at the Chelm cement plant in Poland.
Klaus Moellenbeck of FLSmidth Wuppertal GmbH gave details on the importance of sampling and sample handling. One of the first questions that must be answered is how large a sample must be to be representative of the whole, which depends on the particle size. The new EF sampler from FLSmidth Wuppertal (named after the two inventors) can be used to take a representative sample from a pressurised horizontal tube, for example a pneumatic conveying line for bio-fuels such as wood chips or sawdust. This is likely to have increasing use in AF in the cement and lime industries.
The final presentation at the conference was on the burners that are in use at the Büyükçekmece cement plant, which delegates visited the very next day, given by Con Manias of FCT Combustion. FCT uses a variety of techniques to model combustion processes, including water bead models, acid/alkali models, mathematical modelling and CFD modelling. This can help to optimise the fuel mix, to optimise the burner position and insertion distance, the quantity and pressure of primary air and other factors. Con stated that clinker temperatures have to be sufficiently high for clinkering reactions to occur, and that this can be a problem with some alternative fuels or AF mixes. Burner design must optimise the heat flux profile and fuel burnout. If the burner is not optimised, there can be very high 'hidden costs.' FCT modified the pre-existing burner at Büyükçekmece, using FCT's Lofting Air Technology, in order to give the best possible dispersion of the AF into the main kiln burner. Three burners have been modified with resulting higher use of AF, as well as low CO and NOx levels.
Farewells and awards
At the end of the conference, delegates gathered at the Farewell Party, where a number of event-related awards were presented. Untha was judged to have had the best exhibition stand. In the best presentation awards (voted for by delegates), Neville Roberts, Matthias Mersmann and David Hooper all had 'highly commended' papers. In third place overall, with his paper on Tyrannosaurus equipment was Jori Kaaresmaa from BMH Technology. In second place was Con Manias of FCT for his paper on burner modifications. However, the winner of the best presentation award was Turgut Bayraktar of Hanson Cement for his honest and eloquent paper on the real problems and real solutions involved in the use of AF.
Delegates rated the conference highly for its technical content and for its usefulness for making contacts. At the end of the conference, delegates had the following things to say about the event:
- Generally very good conference;
- Great conference - very pleased
- Speed-dating and networking on the field trips were very good.
- Great conference!
Where next?
At the conference, there was much talk about the huge potential for the use of AF in India, with the country's cement production capacity standing at around 300Mt, its TSR standing at less than 1% and perhaps 20Mt of AF already being produced each year. All agreed that someday India will become a huge user of AF, but the consensus reached at the conference was that this will not happen until effective landfill laws (and taxes) are established - and that this will not happen within the next decade.
Potential delegates were given the opportunity to vote on the location of the next CemFuels conference. The opinion of the global AF community was clear. The 8th Global CemFuels Conference, Exhibition and Awards will take place in sping 2014 in Vienna.
See you there!
