16th Global CemFuels Conference 2023
20 - 21 September 2023
The 16th Global CemFuels Conference has successfully taken place in Istanbul, Türkiye, supported by the Turkish cement manufacturers' association, Türkçimento. In total there were 205 registered delegates at the event from 41 different countries - a new record for attendees - as well as 30 exhibitors. The event will next take place in Dublin in September 2024.
(Above: 'Ladies of Alternative Fuels' at the Global CemFuels Conference 2023)
View the Global CemFuels Gallery 2023
Short Course
Around 30 delegates took the opportunity to attend the Alternative Fuels Short Course, hosted by Stéphane Poellaer and Michal Hinkel of Alterline, on the day before the start of the conference. Delegates said the following about the course:
- Loved the information: Great crash course on AF - well done!
- Thank you so much for this valuable course
- Extremely insightful and useful, with well-informed presenters
- Really interesting - lots of information
Conference first day
At the start of the conference, Ms Canan Derinoz Gencel gave a welcome to Türkiye on behalf of the Turkish cement manufacturers’ association, Türkçimento. Canan mentioned that Türkiye used around 1.6Mt of alternative fuels in 2022, a thermal substitution rate (TSR) of 10.1%, after using only 47,000t in 2007. RDF and TDF each account for around a third of the supply of AF. Around two thirds of the RDF is of industrial origin, with a third being domestic waste. Türkiye aspires to use the same level of AF as the EU, which is currently at 52%, by 2050 at the latest. The rate limiting factor at the moment is the supply of alternative fuels, particularly biomass, and Canan suggested that local municipalities should be encouraged to establish facilities for processing waste.
Jens Breidenbach of KHD Humboldt Wedag gave the first of the event’s technical presentations. He started with an impressive map showing that the majority of Turkish cement plants use KHD’s equipment, and pointed out that the country has traditionally been an early adopter of new technology. Jens introduced the KHD Pyrorotor, which is a rotating drum that can accept very coarse alternative fuels, up to the size of whole tyres. Tertiary air is fed into the Pyrorotor, which first dries the AF and then pyrolyses the fuel, creating a lean gas which passes to the calciner. The material retention time depends on the variable rotation speed and is up to 10 minutes. The largest currently available version can process up to 50t/hr, and the company currently has 14 case studies either completed or under execution, many of them in South Korea.
Matthias Schumacher of aixergee GmbH gave some details about AF use at Spenner Zement, in particular a project to reduce blockages in the calciner. Using CFD analysis, Matthias showed that stratification, recirculation and overheating had led to the coating formation. The coatings had constricted the calciner, leading to higher gas speeds and reduced retention times. Meal spillage also meant that undecarbonated raw materials could fall into the kiln, which meant that the kiln needed to be ‘over-fired.’ The decision was finally made to replace the calciner during a retrofit project, to provide optimised combustion and to reduce NOx formation. Production was increased by 15%, but heavy coating formed in the kiln inlet, leading to daily cleaning. It transpired that the plant’s very short kiln (40m, the second shortest in the world) meant that a proportion of the main burner lignite fuel was not fully combusted by the time it arrived at the kiln inlet chamber. The plant’s burner was improved to increase turbulence and burnout, and this not only ameliorated the inlet chamber problem, but also allowed the plant to start to use animal meal (meat and bone meal, MBM).
Tim Hamer of Vecoplan mentioned that the easiest way to start to prepare alternative fuels is to use a single step shredder. A further shredding stage will result in a more sophisticated product, allowing for density separation, inerts separation and effective particle size control. Pre-separation of high-chlorine plastics and metals may provide a lucrative byproduct stream.
Luigi Di Matteo, CEO of Di Matteo Group, a German company with Italian heritage, spoke about how to achieve consistent alternative fuels to allow maximum TSR. Di Matteo supplies equipment in all areas of AF use, from reception, storage, processing, conveying, dosing and beneficiation. New diverter gates being offered by the company for pneumatic conveying systems not only decrease the capital cost of the system, but also the pressure drop and thus the operational cost.
Gökhan Keskin of ATS spoke about his company’s AF capabilities, and mentioned some new developments. Firstly, ATS has a new offering of an air floating belt technology, while a belt twisting device ensures that the same belt surface is used each time in a pipe conveyor, optimising wear of the belt. The Twin Doseahorse is a compact dosing extractor which can dose different amounts of AF to two different injection points. Automatic cranes are now equipped with anti-sway technology, a mathematical approach, which reduces crane grab cycle times, while regenerative electrical production is used on the crane grabs as well. Finally, a new image analysis system can assess tyres prior to feeding, to avoid blockages and to optimise feeding rates.
Olaf Michelswirth of Intercem Engineering spoke about two case studies on AF receiving and dosing, one without intermediate storage and one with. At the first, the company had to design a truck receiving station in a very awkward site, which, as Olaf put it, “would not win any beauty awards,” but which has also “worked like a Swiss watch” for two years. In a second case study, with automatic storage and reclaim, the truck receiving station is designed to process fluff for dosing to four different cement kilns on the same site, incorporating a variety of separation stages to further improve alternative fuel quality.
Uwe Maas, ThyssenKrupp Polysius presented a case study describing how a Prepol SC-C type step combustor was successfully installed at Oyak Çimento’s Adana plant. As Maas explained, reaching a higher thermal substitution rate of alternative fuels (AF) on a pyroprocessing line with a separate line calciner (SLC) presents plant operators with a number of challenges including AF/raw material drop out, temperature fluctuations in tertiary air, volume fluctuations and the fact that the tertiary air duct elbow, at the base of the SLC, needs to be cleaned on a regular basis. Oyak Çimento operates a 4500t/day preheater kiln with an SLC extension at the Adana site and encountered these problems. The Prepol SC-C was recommended as it is used to dry and ignite coarse fuels, can be used for higher grade AF and lends itself for retrofit projects where space is tight. Initially upon installation, the thermal capacity was not much higher than the old direct feeding system and high levels of unburnt AF in the elbow and high emission peaks of CO were noted. This was remedied by the addition of a small tertiary air duct branch for defined combustion, as well as meal splitting and the use of computational fluid dynamic (CFD) modelling for additional optimisation. Subsequently, the TSR rate at the calciner rose from 13% to 35% and the mass flow from 4t/hr to 12t/hr. The step combustor feeds mainly commercial and industrial waste into the SLC. Further planned works on the setup include improving the ID fan and drive to increase the gas volume capacity, further reducing the need for cleaning at the elbow, increasing the calciner nozzle velocity and using more tyre chips. Denizhan Kilinc, Oyak Çimento then joined Maas to answer audience questions.
Next, Erwan Godard from Hofmann explained how his company’s AB 9000 Active Balancing System product could be used to rebalance a cement kiln ID fan to reduce shutdown time caused by sulphur build-up due to the use of AF. The system monitors vibrations and can be configured to automatically rebalance a fan once a set threshold has been reached. Notably, the product can do this during operation with no need for stoppage. It accomplishes this through the use of two balancing rotors that can be adjusted via non contact transmission by activation of stator coils. In an example given at plant run by Solusi Bangun Indonesia, vibration peaks of up to 8mm/s were recorded before installation and then reduced to 3mm/s subsequently. The intention is to reduce the need to stop a kiln’s ID fan for cleaning. After the presentation an audience member noted that fan shape and kiln chemistry also play a major role in the build-up of debris on a kiln ID fan.
Eugen Becker of Eggersmann Anlagenbau GmbH discussed how his company uses mechanical biological treatment (MBT) to convert municipal solid waste (MSW) into refuse-derived fuel (RDF). After presenting an economic case for MBT, he talked about his company’s Teuton ZS 50/ 55 slow speed shredder for pre-treatment, with a capacity of 45t/hr, and above 50t/hr with MSW. Then he detailed how the company’s RDF production plant in Sulaymaniyah, Iraq, uses the Convaero Bio-Dry product, a membrane-covered system for composting and biological drying of MSW. The site uses 21 lanes to reduce the moisture content of MSW from 52% to 20% in 20 days, with one lane turned per hour by use of the Backhus Con 60 turner. Material from pre-shredding is moved by trucks or wheel loaders to refinement at the site. Later, low calorific fractions are removed in refinement, with fine shredding to 50mm and the option for size fractions at 30, 60 or 80mm. Subsequently, audience questions centred around the viability of converting MSW into RDF.
Global CemFuels Awards 2023
After the first day of the conference, delegates enjoyed a lively dining cruise along the Bosphorus, during which time the Global CemFuels Awards were presented. Nominatoins can be made by anyone in the industry, and are subsequently voted on by industry participants. The outstanding AF project award went to ATS for work at the Medcem plant’s storage and feeding line, while the AF-using company of the year award went to OYAK Çimento - a popular choice. WKE (Waste Knot Energy) received the prize for AF-supplying company of the year, and ‘most innovative technology for AF use’ was presented to A TEC for its Rocket Mill. The award for ‘outstanding contribution to the promotion of the use of alternative fuels went to Türkçimento,’ the association of Turkish cement manufacturers.
Three attendees were presented with ‘Personality of the Year’ awards - catching up after Covid; Michael Suppaner of A TEC; Enrique Rozas of Drake Cement and Karel Jennissen of N+P International - worthy winners all.
Second day
The second day of the conference was started by Ahsan Anis from Power Cement of Pakistan, who pointed out that there is no separation of waste at the domestic level in the country, so that MSW is a very poor prospect for fuel, since it is totally mixed, with food waste and other waste mixed. However, Pakistan is a very major agricultural producer, albeit with much of the waste burned in the fields. Wheat, rice and maize waste are all burned in the open and Ahsan suggested that if they could be collected, they would make good biomass fuels. Power Cement has started to use sugarcane press mud, left after sugar filtration, which has a CV of 3000-3500kCal/kg on a dry basis. The ‘mud’ has a moisture content of up to 45%, so it must be air dried before use.
Christian Ortkras of Westeria next spoke about his company’s capabilities in alternative fuels, including wind-sifting machines, spreading machines and conveying solutions. Fine dosing of AF can be achieved with a veritable daisy-chain of walking-floor receiving stations, a steep tumble conveying belt with height adjustable stripping wheel, a weigh belt feeder and air-supported conveyors. Christian mentioned the use of palm kernel shells (PKS) at a cement plant in Nigeria, which are fed at a rate of 30t/hour, and which have a density of 0.6t/m3 and high calorific value, but which can be abrasive on machinery.
Michael Hinkel and Stéphane Poellaer of Alterline next spoke about the key steps for successful AF implementation. “Typical failures of AF projects can be avoided by a systematic and pragmatic approach based on experience and training of staff.” Stéphane mentioned that clients still rely on a lot on ‘natural intelligence,’ the human brain, to make decisions, which was a nice contrast to the many other presentations that mentioned so-called ‘artificial intelligence.’
Lars Jennissen of N+P Group explained about his company’s AF production approach, which is applied to N+P’s 670,000t/year production capacity. “Our metal extraction needs to be good, because you do not want to have metals in your pellet press,” he started. The company now uses live near-infrared analysis to infer CV, moisture content and chlorine content, so that formulations can be adjusted in real time. Lars mentioned a PAF pellet (pulverised AF) which can be milled into a finer final fuel.
Joana Bretz of TRIE Engineering next spoke about achieving the least fuel cost though the use of AI, using the example of a Brazilian cement plant. The plant was using petcoke with 7% sulphur (!) as well as a variety of AFs with low to very high chlorine contents. It took a day to receive the results of testing of each lorry load of AF, so that the plant was effectively ‘flying blind.’ Joana detailed a computerised system that took into account 2000 variables, including fuel costs and CV, as well as the heat balance of the system. The system allows analysis of various ‘what-ifs?’ of fuel mixes, and their likely effects compared to key production goals. These are presented to the control room staff for their decisions. The next step would be to use the system’s conclusions in the plant’s expert system, to automatically choose the fuel mix.
Jan Tuma of Beumer Group Czech Republic started off by saying that a reliable gravimetric feeder is the heart of every alternative fuels system. Beumer offers a series of ‘Optifeed’ gravimetric weighfeeders. The latest OptiFeed B is a belt weighfeeder, with a completely enclosed cleated belt which allows the feeding of coarse 3D materials of up to 250mm, at up to 35/hour, without risk of blocking or winding with 1D tapes, and at an accuracy of +/-1%. Alternatively, a screw conveyor may be used in case of fine materials. Three such units have been sold to the Oxyfuel pilot project at Mergelstetten in Germany, with commissioning in 1Q24.
Berthold Bussieweke from Thorwesten Vent and Carsten Pries from robecco next spoke on explosion protection concepts for AF. Berthold started by saying that nowadays, the hinged baffleplate used as a venting device is fabricated from carbon fibre to make it as light as possible. The self-reclosing devices then prevent the ingress of oxygen to avoid ongoing fires, as well as preventing the leakage of CO2 or nitrogen inerting gases. Carsten pointed out that highly dried sewage sludge presents the same risk of fire or explosion as lignite, especially since self-heating of sludge may end with self-ignition by biological processes. For an explosion to occur, you need a fuel, oxygen, an ignition source, a particular dust concentration and confinement: robecco seeks to avoid any explosion through continuous monitoring and through the replacement of the oxygen source by purging with nitrogen or CO2.
Ondrej Kozel of Schenck Process Europe then gave delegates details on alternative fuels feeding, using the MultiFlex gravimetric weighfeeder. New innovations - particularly the use of a flexible screw - will increase the accuracy of the weighfeeder to +/-0.5%.
The penultimate presentation was given by Michael Suppaner of ATEC who reminded delegates that even if Germany is at a TSR of 80%, India is still at 3%. Why this big disparity? He said that in his home country of Austria, households have to pay to have their waste collected, with the money going to the waste processor, and the cement plant then gets paid to burn the resulting alternative fuel (Euro65 - 100 for low quality RDF, Euro10 - 40 for burning high quality SRF). Even if they lose some production from AF use, the cement companies receive a very attractive RoI. However in the USA for example, the focus is on returning value to shareholders, so that longer-term investment in equipment to be able to use AF is not prioritised. In addition, generally, politicians are not willing to lose votes for instituting laws to outlaw landfilling and to potentially institute a tax on waste disposal. “Only politics can change this situation!” Michael showed figures that indicated that at nearly any level of TSR, the use of AF will make money for the cement producer. A TEC can help to make it happen, perhaps with a Rocket Mill, which can reduce AF to a fluffy high-surface area fuel, suitable for firing into even a short-residence-time calciner.
Petro Cella of Entsorga was the final speaker, and he spoke about mechanical biological treatment of MSW, which can lead to a reduction in moisture content of 30-40%. He said that the technology for a project must be proven and bankable (“No problem”). He described a project in Indonesia (population 300million), which has taken 13 years to come to fruition. The project by Indocement was for storage, feeding and dosing of SRF, and was one of the first for alternative fuels in the country.
Farewells and prizes
After the conclusion of the conference programme, delegates enjoyed a sunset reception overlooking the Sea of Marmara, where the conference prizes were presented. Based on voting by the delegates, Michael Hinkel and Stéphane Poellaer of Alterline received the prize for third placed paper, while Joana Bretz of TRIE was awarded second prize for her presentation on optimising the fuel mix. A surprised Michael Suppaner of A TEC won the prize for the best presentation for his speech on why AF usage varies so much around the world, and how the numbers can be improved.
Delegates rated the event very highly for its technical content, networking and business opportunities, as well as for its organisation and time-keeping. As one delegate said, after marking the event as ‘Excellent’ in every category on the delegate survey, “Really the best conference I have attended ever. Thank you very much!”
The 17th Global CemFuels Conference on alternative fuels in the cement and lime industry will take place in Dublin in September 2024.
Below: Serial winner Michael Suppaner of A TEC in full flow at the conference...
