10th Global CemFuels Conference 2016
22 - 23 February 2016
The 10th Global CemFuels conference and exhibition on alternative fuels for the cement and Lime industry has successfully taken place in Prague, with 170 delegates, 35 exhibitors and two cement plant field trips.
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The 10th Global CemFuels conference featured a major exhibition of international suppliers of alternative fuels (AF) equipment and services, which was busy throughout the event.
The keynote presenter at the conference was Sussan Pasuki of HeidelbergCement, who spoke about her company’s reasons for trying to use more alternative fuels and raw materials. She stated that the aim was to create a more ‘liveable’ environment. The Paris Cop21 agreements were followed by the WBCSD’s CSI members pledging to reduce their CO2 emissions by 20 - 25% by 2030. Indeed, there have been various calls to phase out the global use of fossil fuels by 2050. HeidelbergCement has been developing new low energy clinkers, new production methods without using fossil fuels, and is active in CCS (carbon capture and storage) projects. Production optimisation is ongoing, in order to reduce the energy consumption for clinkerisation. Waste markets are continually changing, seemingly always becoming more difficult to deal with, but the outcome of these changes is to require increased flexibility and a wide fuel portfolio. The cement industry needs a high quality fuel, with high heat value, low moisture, low ash and good burnability, but the market mitigates against all of these, requiring a final balance between quality and cost. In HeidelbergCement’s Central Europe-Central Asia area, 75% of alternative fuels use is RDF, with a further 17% from tyres/rubber. Sussan said that diversification is essential and that the company should increasingly look at the use of hazardous waste as AF. Sussan also suggested that further advances in AF use can be gained through improvements in AF drying, through improvements in burnability through cutting and/or milling the materials, through increasing residence times, through oxygen injection and through new burner types. HeidelbergCement’s merger with Italcementi will undoubtedly bring changes (and new targets). The company will also make great efforts to improve AF usage rates in developing countries, and in the US and Canada, where AF thermal substitution rates (TSR) lag behind the rest of the developed world.
Second up at the conference was Neville Roberts, on behalf of N+P, speaking about the development of a new waste-derived pelletised AF called SubCoal. The material has moisture content of lower than around 6%, relatively high density (450kg/t) and high calorific value (CV) of around 20MJ/kg. SubCoal is millable with coal, meaning that no significant investment is required. The material is hydrophobic and can be stored outside prior to combustion. Full scale trials of milling and usage are ongoing.
Andy Hill of SUEZ next gave an overview of AF markets in Europe. His company recovers around 60% of the waste it collects in the UK, and it also operates in a number of other countries around the world. Andy first said that it is next to impossible to forecast the future oil price: the level of overcapacity is only around 2%, but prices have dropped 75% from their peak. Petcoke pricing has also dropped, by around 50% in the last 12 months. Andy pointed out that the daily rental rate of a Ferrari F40 is around US$5600, which is cheaper than renting a Capesize bulk transporter, at around US$1600/day. This is bad news for shipowners, but good news for AF producers that want to open up new markets. Andy said that the EU now aims to create a circular economy, minimising the use of virgin materials and maximising the use of waste and by-products from other industries. European legislation is now being augmented to make the circular economy even tighter, using mandatory separate collection for municipal wastes and further reducing waste going to landfill. The putative target for recycling in Europe will be 75% of all materials, with higher levels for metals and plastics. Carbon prices are also likely to be driven up through legislative action, partly through restricting the number of permits issued. Standards legislation will also be brought into being for alternative fuels, improving traceability, driving out of business some less scrupulous operators. Andy pointed out that the cement industry is now in competition with many other industries for AF, including lime, energy, steel, chemicals and glass industries. Andy concluded that the AF market worldwide could amount to over 40Mt/year.
Ed Verhamme of Alternate Resource Partners spoke about how to identify the right waste markets for AF (‘and R’). Ed suggested that in that the CO2 per tonne of clinker produced will be one of the key performance indicators in the future, lower fossil-fuel-intensive fuel mixes will be used, there will be a lower clinker factor and CCS will become a reality. Ed presented data showing not only the mix of means of waste disposal in different continents, but also the variation in waste mix between developed (mainly paper and plastics) and developing (higher levels of organics) countries. Ed suggested that the outlook has changed from a ‘waste’ mindset to one of ‘How can we handle our discarded resources in ways which do not deprive future generations of some, if not all, of their the value?’ Ed spoke about a factory in the Netherlands which is taking waste water treatment sludge, which might currently be used as a fuel in the cement industry, but which is being broken down into its component parts of paper fibres and of organic waste, with each of these separated commodities being used as raw materials in paper-making and as fertiliser: in the waste hierarchy, these uses would outrank the use of dried sludge as fuels in the cement industry in the traditional waste hierarchy.
A pair of speakers, Pier Cella Mazzariol from Entsorga and Gianni Gallozzi of Italcementi, next spoke about Entsorga’s 100,000t/year MBT facility in West Virginia, just 120km from Washington DC. The biological drying plant will produce around 50,000t of ‘Prometheus’ solid recovered fuel (SRF) with Cl at less than 0.3% and this will be delivered to the nearby Essroc cement plant to be co-fired with coal. The US$25m unit will come on-stream at the end of 2017. Mr Mazzariol pointed out that the facility can only come into being with the strong support of a variety of local bodies, including the waste provider, funders and lenders, the Environmental Protection Agency and the cement plant, working together, finding solutions together. The EPA in particular pragmatically awarded the input into the facility’s material stream the status of ‘non-waste,’ making its creation significantly easier. “It is essential to have a ‘take or pay’ contract from the cement plant,” he said, “in order to make the project bankable.” In the end, all participants involved in the project can report a ‘Win’ outcome from the new plant - and this is a project that has been created on a ‘pure market’ basis, without subsidies. The project - which started after a conversation at a previous Global CemFuels Conference - will have taken around four years from start to finish, but could be replicated in a much shorter time in the future.
Markus Binding of Convaero presented the results of three years of operation of a bio-drying MBT facility in Kula, near Istanbul, Turkey, operated by Cementir Holding and Recydia. The project was built in stages, culminating in the creation of 35 covered bays, each holding 600t of MSW. The essence of Convaero’s technology comprises a covering membrane which prompts temperature rises while reducing odours, and active aeration. The organic content of the received waste is around 50%, with mixed paper the next largest fraction, followed by plastic films, textiles and rigid plastics. Moisture content of the received waste is high, at perhaps 55%. At all stages of treatment, saleable fractions are separated for sale. Markus stated that material can be produced in as few as 15 days in the hot summer months, but will take as long as 25 days in the cold winter months, meaning that the throughput of the plant is reduced in the winter. Output from the plant is at a moisture content of less than 20%, with CV of 2850kCal/kg and Cl content of around 0.75%. Ash content is around 25%, density in a walking floor truck is 750kg, but baled waste has a density of more than 1t/m3. Lessons to be learned from the project would include the importance of having a well-trained team ready for the commissioning of the plant, the importance of maintenance, process control and continuous improvement. Markus baldly stated that if there is no gate fee, “there is no business.” At the other end of the factory, SRF is a real product, he said, which must command a real price, based on Euros/GJ.
Christophe Garcia of shredding machine manufacturer Precimeca next gave some ideas on how to select the best tyre shredder for the production of RDF, in association with Vicat Turkey. Christophe first of all stated that “Tyre-derived fuel (TDF) is first-class alternative fuel.” TDF has a high CV, stable and homogeneous properties, low sulphur content and a high biomass fraction (20% for passenger car tyres, 30% for truck tyres). TDF may in turn have an average mix of 70% passenger car tyres and 30% truck tyres. He suggested that a shredder should be designed to create a clean cut, so that the metal bead of the tyre is not left outside the shredded particles, since this can lead to problems in handling, wear and blockages. The company’s NEO tyre shredder can provide such a clean cut. Blades take around a day to change, while the blade lifetime is around 2500 hours.
Jori Kaaresmaa from BMH Technology and Ms. Ursula Kääntee of Finnsementti next co-authored a paper on how to match quality and price, in this instance producing AF for a 40-year old kiln. Finnsementti has managed to reduce its specific CO2 emissions by 27% since 1990, largely through the use of AF. The Parainen cement kiln has a 2200t/day cyclone preheater kiln with riser firing, and this kiln uses waste oils, MBM, TDF and SRF. Jori pointed out that the SRF price must be cheaper than coal and allow both parties to make a profit, while a long-term delivery contract must also exist. SRF quality is specified in the contract, and there should be appropriate ‘carrots and sticks,’ in order to ensure quality compliance. BMH Technology’s Tyrannosaurus shredder has a MIPS, or massive impact protection system, which avoids shaft and blade damage from foreign bodies in the waste, (which may occur even in pre-sorted waste) such as chunks of steel, bicycle frames (or even dead dogs). A special system (‘Zero Gap’) ensures that the gap between blades and cutting frame is practically zero, which improves cutting quality. The SRF production system at Finnsementti is sized to be able to produce around 25t/hour, at a size of <80mm. Having a single SRF supplier, rather than a range of suppliers, can be a distinct advantage, potentially for both sides.
Robert Jansky of Cemmac, a cement plant in Slovakia, introduced the next presentation: His company’s five-stage precalciner plant has used AF since 2004, in the form of whole tyres, and later RDF, at a rate of 10 - 20%, peaking at 50%. 60% of the fuel is fed to the kiln and 40% to the calciners, although RDF firing into the calciners is limited to 1t/hour or 20%, due to high CO levels measured at the exit of the stage 4 cyclone (with stage 5 being the bottom stage). However, even with the firing of pure coal, the firing rate is limited by CO levels, which in turn limits the degree of calcination and overall plant capacity. There are also severe problems with sulphur-based build-ups forming in the area above the kiln inlet chamber: in order to remove the build-up, the kiln is stopped for several hours roughly every two weeks. The kiln also suffers from a reducing zone, since unburned AF particles can fall onto the clinker bed. The second part of the presentation was given by Con Manias of FCT, who explained how some of these problems were solved. Con pointed out that the base problem was a high variability of sulphur volatility. He showed that the unburned AF landing on the clinker bed led to reducing conditions which led to volatilisation of sulphur and subsequent problems. This can happen with low momentum burners, but this particular plant had a burner of adequate size. Another problem was that there was a relatively high chlorine level in the meal, which was not being fully addressed by an under-sized chlorine bypass. The plant had been adding gypsum into the raw meal, and it was suggested that this should be stopped. Con reminded delegates that particle combustion happens in three stages: drying, torrefaction and final burn-out of char particles. The burn-out time of many of the RDF particles was longer than the residence time in the calciner. By relocating burners in the calciner, it was possible to start char burn-out much earlier, leading to more complete particle combustion. It was suggested that feeding a finer AF would allow 100% burn-out of particles. It was also suggested that the shape of the main burner flame should be modified to avoid particle impingement on the clinker bed.
Gala Dinner and Global CemFuels Awards
After the first day of the conference, delegates travelled to the elegant Lobkowicz Palace in the grounds of Prague Castle for a sumptuous banquet of Czech cuisine. During the meal, the 2016 Global CemFuels Awards were presented, after a global online nomination and voting process. Outstanding AF project of the year was awarded to Cemex/SUEZ for the Malpass Farm unit in the UK; AF project manager of the year went to Frederico Contente of Masias, Spain; The AF-using company of the year was LafargeHolcim (for the first time); AF-supplier of the year was N+P of the Netherlands; The most innovative technology of the year for AF was Lindner-Recyclingtech’s shredders and the Global CemFuels ‘personality of the year’ was Jan Theulen of HeidelbergCement. Many delegates finished off the evening with a convivial visit to the U Vejvodu hostelry in Old Prague.
Conference second day
On the second day of the conference, Daniel Wresnik of Untha (and co-authors from Geocycle) spoke about a single-cycle shredding solution for SRF, using a case study of processing of footwear manufacturing waste in Vietnam. Geocycle made a first inquiry to Untha in a two-line email, back in September 2014, but just one year later, in September 2015, the machine was already installed in the factory with a signed acceptance test. The waste handling facility receives 4000 - 5000t/month of waste. The unit uses a single shredding rotor with 21 blades, and features inbuilt fire fighting systems. Throughout is approximately 10t/hour, with a material density of approximately 100kg/m3.
Svend Christensen of Metso and Ivo Raadla of Technobalt Eesti Ltd (Estonia) co-authored the next paper, on the selection of shredders for AF. “Selecting the right shredder is not a science, it’s an art,” concluded Svend Christensen.
Luigi Di Matteo of Di Matteo GmbH and co-authors from Dyckerhoff Eastern Europe started the next conference session on handling, feeding and dosing, by speaking on ‘key factors for the successful use of AF in the cement industry.’ Luigi mentioned that the characterisation of the AF is a crucial first step to be able to handle and dose the material, while the safety aspects of AF have also become more important over the years. He pointed out that different particle sizes and shapes will ‘fly’ differently upon injection into the kiln, while each different kind of material in an RDF mix will have its own combustion rate and characteristics: these must be taken into account not only when planning combustion, but also in the material mix and in the fuel preparation. Any ‘error’ in fuel preparation will be propagated through the system and will finally be revealed in the pyroprocessing system (as mentioned by Con Manias the previous day in his presentation on the reducing conditions encountered when using a too-coarse AF at a cement plant in Bulgaria). Luigi Di Matteo gave some details of an RDF flash dryer installed by his company at Buzzi Dyckerhoff at Nowiny, Poland, which was chosen over a drum dryer, having only 30% of the comparable investment cost. The flash dryer - using exhaust gas from the cooler at 190°C - has the effect of reducing the moisture content by up to 8%, but also of reducing the level of inserts in the RDF. The calorific value (CV) value of the material was increased by 2mJ/t, while 20t of rejects were produced each month, reducing wear on the system: maintenance and operating cost is around Euro0.7/t of RDF.
Leoš Voleský of Schenck Process next spoke on solutions for efficient feeding, with co-authors from CRH Ozarow and from Titan Cement Alexandria. Leos state that the quality of AF being used in cement plants has reduced over the years, requiring improvements in equipment and processes by the users. For example, the trend is towards larger particle sizes, higher moisture contents and higher compressibility in AF. In a sentiment also echoed by other speakers, Leos suggested that the reality of preparation of AF represents a series of compromises, particularly because capital expenditure budgets are still restricted, with a requirement for a fast return on investment. Leos mentioned the use of an over-belt IR-based on-line analyser before the main storage at the Ozarow plant, which assesses a continuous 1% sample of the AF stream for moisture and chlorine. Signals from the analyser are matched with an extensive database of materials. If aberrant levels are detected, then material reception is suspended and previously fed materials are sent to a reject silo for subsequent low-level feeding into a higher quality AF stream.
Next Thomas Jennewein of FLSmidth Pfister GmbH and his co-author Franz-Joseph Schäfers of Spenner Zement GmbH gave an overview of AF usage at Spenner Zement since 1993. The plant started using fluff, but the earliest solution for dosing was ineffective: weighfeeding and dosing from Pfister was instituted, allowing higher TSR. Later the plant started to use meat and bone meal (MBM) which was enabled by a Pfister rotorweighfeder. In 2011, the plant invested in a TRW-S/D rotor weighfeeder to allow feeding and accurate dosing of low but variable density RDF (0.1 - 0.3t/m3) to the pyroprocess. Thomas echoed the sentiment that AF quality has decreased over the years and said that it has become essential that the wear parts are easily exchangeable. The slow rotation rate of the rotor weighfeeder, of around 4rpm, means that the device has low inherent wear in any case. Thomas mentioned an example of dosing wood dust into a lime kiln in Scandinavia, with bulk density 0.15 - 0.25t/m3 and moisture content of 15%.
Pascal Gübeli of SID SA, in a paper co-authored with Sinoma, next spoke about the feeding of pasty and hazardous fuels using the ‘Shredding, Mixing, Pumping’ SMP system. Pascal reminded delegates that hazardous materials are characterised by high ignitability, high reactivity, high corrosivity and also high toxicity - sparks must be strenuously avoided and generally the temperature of the material must be kept low, while preparation must be undertaken in an inert atmosphere. Due to the constraints of processing, preparation is expensive but the high gate fee and high calorific value can more than make up for this. The input into the SMP system is a solid/pasty mix of industrial and hazardous materials, but the output is a pumpable slurry. The SMP system uses a low-speed rotary shear shredder, with N2 blanketing, an anti-explosion system, a horizontal single-shaft shovel mixer, a double-auger piston pump and a special chute to a sealed hopper for any unshreddables. The slurry is finally introduced into the calciner system using an air-cooled lance.
In the final session of the conference, on combustion optimisation, the first paper was given by a consortium of researchers from Portugal: Sandro Conceição from AVE and Iñes Costa from consultancy 3Drivers spoke on behalf of the consortium on the use of AF in Portuguese cement plants. AVE acts as an effective middleman between the waste collectors and the cement plants. Iñes pointed out that the loss from the circular economy of around 50% of materials without any recycling is an economic inefficiency with a price of around Euro200/t - and at an average level in Europe of around 8t/person/year. Alongside the main collectors of the waste in Portugal, the consultancy effectively invented from scratch a full legal, technical and practical framework to enable Portuguese cement plants to coprocess AF in cement kilns. The study led the Portuguese authorities to instigate a taxation system on waste destined for the cement industry that allows a fair sharing of the benefits of recycling, and a certainty for all participants of the basis of future waste use in the cement industry.
The penultimate presentation at the conference was given by Jan Spacek of Geocycle, speaking on the use of AF at LafargeHolcim’s Cizkovice plant, which was visited by delegates just before the conference. Jan reminded the audience that because the plant is so close to the German border, only 85km from Dresden, around one third of the plant’s sales go to the German market. The plant was established in 1898 and was largely reconstructed after Lafarge became a majority owner in 1992. The plant has a single rotary kiln with a five stage preheater with precalciner, with a clinker production capacity of 2250t/day. 55% of heat input goes into the calciner and 45% into the main burner, with a variety of types of AF being fed into each. As delegates saw for themselves, there are separate fuel collection and preparation areas for the calciner and for the burner fuels. Jan pointed out that the AF systems did not come into being overnight, but that they are the result of a long-term organic growth of the facilities since 1997. Significant developments included the construction of a ‘Waste City,’ a waste storage and pre-homogenisation shed in 2009 - 10; the creation of a chlorine bypass in 2010 - 11 to allow an increase in the use of solid shredded waste (SSW) on the main burner and the control of build-ups; and the construction of a new calciner channel in 2012 - 13 to allow further increases in the level of AF usage. The plant now has a TSR of 90%, using solvents, several types of sludge, shredded tyres, impregnated sawdust, wooden chips, fine rubber and animal meal. Jan reminded delegates that the car industry is highly developed in the Czech Republic, producing more than 2m cars each year, so that there is a ready supply of car manufacturing waste which makes a good AF.
The final presentation at the conference was given by Ted T. Reese of Cadence Environmental Energy, co-authored by Milan Stanoev of Titan Bulgaria’s four-stage preheater (no calciner) Zlatna Panega plant. The plant uses tyres and an engineered fuel supplied by a local Titan-owned company GAEA (Green Alternative Energy Assets). The two companies have worked together to reduce CO production (which can arise through incomplete combustion of AF) and to maximise AF usage rates. Cadence supplies ‘Mixing Air Technology’ which decreases stratification in the kiln by increasing turbulence via a pair of kiln-mounted blowers and it was this system that was applied in Bulgaria. The project increased the use of whole tyres from 11% TSR to nearly 19% TSR, with no significant increase in CO. In fact, there were fewer blockages in the preheater tower after project completion.
Farewell and prizegiving
After the end of the event’s presentation programme, but prior to the subsequent day’s popular visit to the Cemex Prachovice cement plant, delegates gathered together for farewell drinks and the presentation of prizes for the most popular presentations, as voted for by the delegates themselves. In third place was Luigi Di Matteo for his co-authored paper on the possibilities of AF preparation at Buzzi Dyckerhoff at Nowiny, Poland; in second place was the multi-author study of AF use in Portuguese cement kilns; while in first place (for the second time at CemFuels conferences) was Ted Reese of Cadence Environmental Energy, for his co-authored paper on increasing AF usage at Titan Bulgaria’s Zlatna Panega cement plant.
Delegates strongly praised this 10th anniversary Global CemFuels Conference, with one Saudi Arabian cement company attendee describing the event as “Better than excellent.”
What the delegates said at Global CemFuels 2016
• Congratulations for the overall experience
• Thanks for the good conference
• Excellent organisation
• Punctuality, professionality, quality
• Great conference, well organised
• Having spent 31 years in the oil & gas, chemicals and petrochemicals, fertilizers and speciality business, I can testify that this event tops all those that I attended in almost everything (Saudi Arabian cement producer delegate)
• Very well organised conference -right place, open peoiple - good chance to make networking and find a solution for many problems related to alternative fuels
• Many thanks for all organisers and standby team of Global Cement.
• Better than excellent!
