15th Global CemFuels Conference 2022
14 - 15 September 2022
The 15th Global CemFuels Conference has successfully taken place in Lisbon, Portugal, after a two-year gap due to Covid. Around 130 delegates registered to attend the event, on alternative fuels (AF), a similar number to pre-Covid, as well as 20 exhibitors.
View the CemFuels 2022 photo-gallery
What the delegates said:
- Thank you very much for the great conference, great support and all the information again. We had a lot of good and interesting meetings, as well excellent contacts with customers and new leads.
- It was a great conference, as usual, perfectly organised by you and your team !
- I think the organisation was very good!
- Conference was interesting (as always) and useful (as always).
- Thank you very much for everything. I have lots of [positive] memories from CemFuels
- This [conference] was very good and useful.
- Many thanks for organisation of this really amazing CemFuels conference this year.
- It was a good gathering. I could combine pre-set meetings, visiting with friends, relaxing, and meeting people I will do business with, so I am glad I went. Good format again with speed-dating, dinner, [exhibition] booths.
- Thanks again for a nice event, [it] was a pleasure to talk to you and your colleagues.
First day
Michele Graffigna of HeidelbergCement ('HC') started the conference by outlining his company's plan to reduce its CO2 emissions by 47% by 2030, compared to 1990. The company's thermal substitution rate (TSR) is 28% in 2022, but the target is for this to increase to 45% by 2030, with 20% overall being biomass such as agricultural waste, biomass waste and biomass from sustainable plantations such as Elephant Grass. The company is using technology in its cement plants to allow an increase in TSR, such as a Prepol firing chamber at Schelklingen in Germany; two belt dryers to treat dewatered sewage sludge using waste heat from the clinker cooler (at Geseke); storing, dosing and feeding impregnated sawdust into a new calciner at the Couvrot plant in France; and construction of a brand new kiln line in Airvault in France with TSR higher than 88%, and which is designed for conversion to oxyfuel technology. HeidelbergCement is also using wood-based construction and demolition (C&D) waste at its Delta plant in Canada. Michele also outlined the many carbon capture use/sequestration (CCUS) projects that HC has undertaken around the world, including at Brevik in Norway, Edmonton in Canada, Padeswood in the UK, and at the new Mitchell plant in the US.
The second speaker was John McFarlane of Albion Design, who stated that "biomass is easier to burn in a cement kiln, but it makes more commercial sense to burn it in the majority of lime kilns." Granulated or pelleted biomass works very well in lime plants, with low moisture and low ash, while simple storage solutions can keep pellets at below 10% moisture and pellets can be micronised like petcoke and lignite. 1GJ-worth of coal creates around 100kg of CO2 and, now that emissions permits are at around Euro85/t, moving to carbon-neutral fuels makes sound financial sense. "If you want it to be considered carbon-neutral, it has to be signed-off by somebody, despite whatever we might like to think. Nothing worth doing is easy," he concluded.
Adrian Irvine at Regen WTE next spoke about the challenges of producing RDF and SRF in Europe, mentioning 'Mr Putin's attempt to move his boundary fence onto his neighbour's property' as another reason for recent increases in energy prices. Adrian asked that the industry should respect the waste hierarchy, and use materials as fuels only if there is no higher-value use for them. He suggested that the testing of inputs into feedstocks is crucial, and that the testing must be accurate and repeated to be effective. Contracts for long-term supply will become increasingly important for users as energy prices continue to rise, and as waste-to-energy plants progressively out-bid the cement industry for alternative fuels.
At the start of the event's session on fuel sourcing, preparation and handling, Josef Imp of Tana Oy of Finland spoke about the importance of versatility in AF production. Josef pointed out that fuels producers are also suffering from increased costs, and that the Tana Shark mobile shredder and screening machine can reduce costs for producers.
Continuing the session, Luc Reiffel of Walter Materials Handling, ATS Group, spoke about his company's capabilities in alternative fuels storage, handling, extraction, transfer and feeding. Luc mentioned that the clear trend is for customers to request much higher capacities than previously, from perhaps 20t/hour previously, to up to 60t/hour currently. Luc gave some details about the automatic crane AF handling system and whole-tyre feeding system at Holcim's Martres plant in France. He also gave details of the new 'TWIN Doseahorse' equipment, which allows two separate dosing points to be supplied by the same dosing unit, and mentioned that two units are currently being commissioned in Thailand and one in South Korea. The 'Walt' AIR' air-supported conveyor belt only requires a support every 47m, reducing capital costs to the lowest possible level.
Ondrej Kozel of Schenck Process mentioned that the company's branch in Czech Republic is the centre of competence for alternative fuels, with around 60 employees working expressly on AF projects. The centre has a dedicated area for testing of customer samples of AF. Covid taught the company how to make remote testing work, with cameras and live sharing of results. Ondrej mentioned that the MultiFlex NG screw weightfeeder is very well-suited to feeding and accurately dosing even problematic alternative fuels, and incorporates a number of features that prevent bridging and 'bundling.' He mentioned a case study of a project at the Holcim Királyegyháza plant in Hungary, which was designed to increase the AF feed rate, to a nominal capacity of 5t/hour. The cost for the project was Euro500,000, but the daily saving compared to using coal was around Euro21,500, suggesting a payback period for the equipment of less than two months.
Luigi Di Matteo of Di Matteo Förderanlagen next spoke on his company's capabilities in producing equipment for conveying, storing and processing of alternative fuels. The Di Matteo '4.0' Remote Service Centre was developed during the Covid times, and has seen such success that it will continue into the future. Luigi sagely mentioned that correct combustion can only be achieved by prior correct reception, quality control, storage, transport, dosing and feeding. Di Matteo offers solutions for all of these stages.
Jan Tuma of Beumer Czech Republic emphasised that flexibility is of paramount importance when seeking to use AF. Multiple different fuels, from multiple different sources, as well as 'spot' occasions for difficult-to-burn materials with high gate fees, require high capabilities from a handling system. Jan presented case studies from Sulaymaniyah in Iraq, from Retznei in Austria and from Denizli in Turkey.
Wolfgang Zschiesche of Vecoplan contrasted single- and two-step shredding as well as pointing out that Solid Recovered Fuel (SRF) is of a higher quality (and higher CV) compared to Refuse-Derived Fuel (RDF), but that neither fuel is ever homogeneous. He reminded delegates that single-step shredding is easy to control, has no possibility for reject materials, is inexpensive and is relatively simple. However, the source material must not contain contaminants, otherwise there may be a process upset. On the other hand, two-step shredding (pre-shredder and final re-shredder) with magnetic separation, EDC and wind-sifting can handle more problematic material streams such as municipal solid waste (MSW), as well as handling higher tonnages, and can produce smaller particle sizes, albeit with higher investment cost and greater process complexity. It is possible to start with a single-step shredder and to add equipment to create a two-step shredding process.
Global CemFuels Awards Dinner
After a short visit to the Padrão dos Descobrimentos monument on Lisbon's seafront, delegates enjoyed an authentic evening of Portuguese cuisine, wine and Fado music at the Pateo Alfacinha, as well as the presentation of the Global CemeFuels Awards for outstanding performance in alternative fuels. HeidelbergCement (now Heidelberg Materials) won the award for 'AF user of the year,' while Vanheede Alternative Fuels of Belgium won for 'AF supplier of the year.' SICK won for 'most innovative technology' for its MCS100FT continuous emissions monitoring system. Outstanding AF project went to Çimsa Çimento's Mersin AF project, while project manager of the year went to Alterline's Stéphane Poellaer. The award for 'outstanding contribution to the promotion of alternative fuels' went to aixergee, part of the Loesche Group. Given the two-and-a-half year gap since the previous CemFuels conference, three 'personalities of the year' were announced: Xavier d'Hubert of XDH energy; Luigi Di Matteo of Di Matteo Förderanlagen; and Luis Realista of Portuguese AF-provider AVE, who was instrumental in bringing the event to Lisbon.
Second day
On the second day of the conference, at the start of the session on pyroprocessing optimisation, Uwe Maas of thyssenkrupp Industrial Solutions gave details of the establishment of a 'new class' of alternative fuels. Uwe gave details of the Polysius Prepol SC Step Combustor, which allows up to 1000 seconds - 17 minutes - of residence time for fuels being fed to the calciner. A steep static grate is fed with AF, which is then transported down the grate by a series of air-blasters at the foot of each step. The air blasts also have the effect of lifting finer particles into the combustion air-stream. The long residence time allows rather coarse AF to be used, "such as from a single-step shredding process." Uwe mentioned a major AF project at TPI Polene in Thailand, capable of handling 4000t/day of coarse (up to 30x30x10cm) and moist (40-55% moisture content) RDF, and including several Prepol Step Combustors.
Liliana Gonzalez Gaitan of Cemex next spoke about the use of hydrogen by the company as part of its efforts to reduce its CO2 emissions by 50% by 2030, using just 'traditional' levers - such as use of AF, reducing clinker factor, using decarbonised raw materials, achieving lower clinkerisation temperatures and producing lower CO2 clinkers and by increasing thermal efficiency - and not relying on 'exotic' technologies such as CCUS. Cemex has a TSR of 30% in 2021, with 11% overall in the form of biomass. Liliana stated first off that if the cement industry is to use hydrogen, then it must be 'green hydrogen' which does not involve the use of fossil fuels at any stage of production - using only renewable energy - and that this is uneconomic at the moment. However, Cemex has found that feeding hydrogen into the kiln improves combustion, producing a brighter and hotter flame, reducing overall fuel consumption and allowing greater use of other AF, by up to around 10% - apparently even at very low dosages (of 1kg/hour). Clinker reactivity is increased due to steady kiln operation, and CO2 and NOx are reduced. Cemex is now using hydrogen as a combustion enhancer in more than 20 plants worldwide. The company is working on processes for innovative hydrogen production with a company, HiiROC, that uses thermal plasma electrolysis. Cemex is working towards the use of hydrogen as a fuel, rather as just a combustion enhancer, and is also looking into the possibility of using hydrogen as a feedstock for other alternative fuels. Cemex is also attempting to convert its Rüdersdorf cement plant near Berlin to become the first CO2-free cement plant. Challenges in terms of cost, safety, and usage methodologies need to be solved before hydrogen can be regularly used. Liliana suggested that there will be an optimum dosage of hydrogen for each cement plant, given its individual pyroprocessing situation and fuel mix, but that 100% hydrogen-firing will be unlikely.
Next up, Marco Lindemann-Lino of the VDZ spoke about 'lessons learned' on hydrogen combustion by the cement industry. The VDZ has already published a roadmap which envisages the use of 'green' hydrogen at up to 10% of the energy requirement for clinkerisation. However, green hydrogen is practically not available at the moment, and scaling-up of production will be required before use at any scale. Current cost for 'grey' hydrogen (which uses fossil raw materials) is in the region of USD1/kg, but is USD8/t for 'green' hydrogen. The cost is a major disadvantage, especially when costly hydrogen competes with biomass and other AF with low or negative cost. Current research areas include the impact of firing with hydrogen on fuel consumption and power consumption of the kiln line as a whole; what is the impact of water vapour on the calcination reaction (is it a catalyser?); and what is the impact of hydrogen firing on emissions. Marco gave details of the fuel-switching experiment at Hanson's Ribblesdale cement plant in the UK, which used up to 340kg/hour hydrogen, while increasing the amount of other AF used at the same time. Varying the velocity of H2 at the burner tip did not have a significant impact on fuel burnout and temperature profiles, although a velocity of more than 275m/s was recommended. In fact, in the experiment, H2 speed at the burner tip was 900m/s, while hydrogen on its own was sufficient to cool the burner tip: At higher H2 firing rates the flame is characterised by a large envelope of high temperature: The flame was bright and radiated to a similar degree to the baseline flame, with similar plume length. Hydrogen oxidises very fast, which could hamper the combustion of other fuels, especially MBM. The clinker bed temperature was similar to the base case, without H2. No clinker sample showed any signs of reducing burning conditions, so that full MBM burnout was maintained, albeit with a short (6 hours) experiment duration and with a limited number of clinker samples. Burner design needs to be optimised for future trials. The experiment concluded that there was a neutral impact on thermal energy demand, no clear conclusions on NOx and CO formation, and no issues with noise, despite the high feeding velocity of hydrogen at the burner tip. However, the conclusions cannot simply be extrapolated for higher H2 TSR, since pure H2 flames are barely visible. Impacts on the clinker burning process when firing a full-time net-zero fuel mix rich in H2 are still unknown. In a study, with H2 cost at the gate of Euro16/kg, and many other costs, using many case-study assumptions, the cost of avoiding a tonne of CO2 by firing H2 would cost Euro1560/t. Using different assumptions brings down the cost very substantially, to around Euro75/t of CO2 avoided, competitive with CCUS.
Stéphane Poellaer of Alterline next asked, "what technical steps must be taken to achieve 100% TSR?" The increase in the cost of coal by 6-7 times in the preceding months has given additional impetus to the use of AF. Stéphane pointed out that there are two main areas that can be improved: pre-processing to improve the quality of the AF by decreasing particle size, water content, ash and chlorine, and increasing volatile content; and co-processing advances to improve pyroprocessing, including improved combustion/burnout at the calciner and main burner, feeding properly, managing chlorine effects, coping with high exhaust gas volumes and other effects. He pointed out that a variety of precombustion systems are now available, not only the Polysius Step Combustor (mentioned above), but also the FLSmidth Hot Disk, the Pyrorotor from KHD and the Fire Bed Combustor from IKN, each with their own advantages and disadvantages. Torrefaction of wood - destroying its structure by subjecting it to high temperature steam - followed by pelletisation; pyrolysis; and gasification are all possible means to increase TSR in the future.
Matthias Schumacher of aixprocess GmbH next spoke about a new 'real time Industry 4.0 optimiser for cement and lime pyrolines.' In fact, aixprocess is part of the Loesche Group, and is well-known as a modelling company concentrating on pyroprocessing optimisation. Matthias pointed out the steps in a 'digital maturity' journey, from the merely human ('reactive'), through a calculative stage, a 'proactive' stage based on data-driven decision-making, through to 'predictive' semi-autonomous operation and finally to fully autonomous operation capable of predicting what will happen to the process "in the next 30 minutes." aixprocess is developing the KILN-pilot for '(semi-) autonomous' operation. Matthias pointed out that the 'house-keeping' required to optimise the process before application of a process control program will already greatly improve process efficiency: KILN-pilot may further improve the situation. Further development is under way.
Stefan Kern of A TEC subsequently spoke about how his company's Rocket Mill and Flash Dryer can help maximise TSR. The Rocket Mill is a shredder but without knives, instead using high-speed rotating chains to crush and comminute alternative fuels, surrounded by sieves to control particle size. Tyres and carpets, which are too elastic, are not suitable for processing in the mill, but other materials will be reduced, rendered more 'fluffy and reduced in moisture content, particularly with use of drying process waste gas in the mill. Single- and double-chamber versions are currently available. Stefan went on to outline the A TEC Flash Dryer, which uses any suitable gas stream at around 160°C to reduce moisture content just before being dosed to the burner.
At the start of the session on best-practice in alternative fuels use, Felix Bartknecht of SICK AG spoke about how AFs affect natural gas flow metering. Around 10% of the energy used by the global cement industry is in the form of natural gas, a share that, despite Russia's invasion of Ukraine and the consequent spike in gas prices, is likely to increase in the years to 2050, partly due to its relatively low pollution compared to other fossil fuels. SICK uses ultrasonic transducers to measure gas flow velocity and volume, with no moving parts, no pressure drop and a high turn-down factor. Felix gave details of a case study at Kirchdorfer Zement, which required the measurement of low volumes of natural gas. He pointed out that measurement of CO2 and H2 will be increasingly required in the future, but that the fact that sound travels at different speed in different gases (and blends of gases) needs to be taken into account - SICK's equipment can not only still measure the volume flows of blends of gases, but can calculate which gases are in the blend, and in which proportions.
Alexander Neagos of KOPF Syngas next spoke on the production of synthesis gas from sewage sludge gasification. From 2029, sewage sludge will not be allowed for use as a fuel in the cement industry in Germany (2026 in Austria). Alexander suggests that gasification is the answer, using the SynGas fluidised-bed reactor, using air as a gasifying medium, at a temperature of 850°C, and with inert ash dropping out of the process, allowing recovery of phosphorus - which can then be used as a fertiliser. The syngas so produced is primarily N2, H2, CO, CO2 and CH4, can be burned at 1500°C, and could also be used for captive power generation. Syngas is well-suited for use in calcined clay production, due to its relatively low temperature at ignition.
The penultimate presentation at the conference was given by a 'tag-team' of Berthold Bussieweke of Thorwesten Vent GmbH and Robert Becker of robecco. Berthold pointed out that a number of alternative fuels present fire and/or explosion risks, so that preparations are crucial to seal the explosion vent openings after release of explosion gases to minimise the ingress of air and loss of any inserting gases. Robert then reminded delegates that combustible dust and air mixtures are dangerous and give the potential for explosion and fire. Early measurement of explosive atmospheres, such as CH4 and CO, is important, so that they can be mitigated with inerting gases which reduce the oxygen content to below the Limiting Oxygen Concentration (LOC), usually with CO2 or N2.
Finally, Kåre Helge Karstensen of SINTEF, a major Norwegian research organisation, brought the presentation programme to a close, by speaking on experiences of co-processing of non-recyclable plastic waste in the Asian cement industry. He pointed out the possibility of there being more plastic in the oceans than fish by 2050. He mentioned the OPTOCE project to reduce plastic pollution to the seas from China, Myanmar, Vietnam, and Thailand, which together have a population of more than 3Bn people. Average TSR in Asia is around 3%, so the potential for increased TSR from AF is huge. As an example of a project, the use of floating material in the Yangtze River has been investigated as a co-fuel. The material is brought to the 5000t/day Zigui cement plant of Huaxin, and contains about 13% plastic, with the majority of the rest being wood. The plant will use around 47,000t/year of floating materials. Kåre stated that in 2005 there were no plants in China using AF, but that "now there are hundreds, and they have invested billions of dollars in equipment."
The conference programme finished with a lively discussion panel, which addressed quests such as 'should cement producers actually target 100% TSR,' and 'to what extent is the use of AF 'green-washing'?' - the answer to that one being 'not much'.
Awards and farewells
At a farewell cocktail party, the awards for best presentation were given out: Alexander Neagos was fourth, Luigi Di Matteo was third, Stéphane Poellaer was the runner-up, and Liliana Gonzalez-Gaitan of Cemex was in first place, with her paper on the use of hydrogen as a combustion enhancer.
In a show of hands, delegates were unanimous in agreeing that a real-world conference was preferable to a virtual event. Many delegates were delighted with the very high level of networking and contact-making at the event, saying that, despite Teams and Zoom, at a virtual event it is impossible to shake someone's hand, to look them in the eye and to have a drink with them. We look forward to the next CemFuels conference!