13th Global CemFuels Conference 2019
20 - 21 February 2019
The 13th Global CemFuels Conference on alternative fuels for the cement and lime industry has successfully taken place in Amsterdam, with 185 registered delegates, 33 exhibitors and 22 presentations on the latest developments in markets and technologies for alternative fuels. The conference included two field trips, to the N+P SubCoal fuel preparation plant at Farmsum, and to HeidelbergCement's CBR cement plant in Lixhe, Belgium (group photo above). The 14th Global CemFuels Conference will take place in February 2020 in Cyprus, with a confirmed visit to Vassiliko Cement.
View the image gallery from the conference
The first presentation at the Global CemFuels Conference 2019 in Amsterdam was given by Frank Brannvoll of Brannvoll APS. He forecast that carbon prices will increase significantly after 2020, once demand for permits increases past available and stockpiled permits. Coal is still very much in demand around the world, particularly in China and India, underpinning global energy prices. Oil prices are expected to be sustained in the US$60-80/barrel level and above.
Michael Hinkel of Geocycle gave the next presentation, on the regulatory framework for alternative fuels (AF). Michael said that following the merger of Lafarge and Holcim and the establishment of the GCCA (Global Cement and Concrete Association) there was a feeling that the guidelines for the coprocessing of alternative fuels in cement manufacturing needed to be updated. Target groups for the guidelines were relevant government authorities, the concerned public and their representatives, NGOs, financiers, waste generators, cement manufacturers, associations and equipment manufacturers. The new guidelines include an extended scope to encompass pre-processing and they emphasise the fact that co-processing is a key enabler of mineral recycling and energy recovery. The guidelines underline the fact that co-processing has a role in the circular economy, in resource efficiency, in mitigating climate change, reducing marine litter and in achieving sustainable development goals (SDGs). He suggested that companies engaged in co-processing should help to establish the regulations that control industrial activity, where the regulations do not exist or are out of date. The guidelines also point out that companies that are involved in co-processing should consult with and consider the interests of informal waste workers (since, for instance, Cairo’s Zabbaleen ‘garbage people’ recycle 85% of the city’s waste, providing thousands of livelihoods).
Alexander Larionov of the International Finance Corporation, part of the World Bank Group, next spoke of the importance of the cement sector in the company’s work. Thermal substitution rates (TSR) in Africa range from zero in some countries, through around a 5% average for the continent, to 15 - 20% for standalone projects in Kenya, Nigeria and Senegal. Very strong potential for AF growth exists in Egypt, with around 2Mt/year being divertable from landfills, with a likely 3 - 5 year payback and 15% internal rate of return (IRR) for good AF projects.
Amie Stringer of Totus Environmental next spoke on ‘alternatives to solid recovered fuels, SRF.’ Essentially Amie suggested the increased use of blended fuels, offering improved chemistry and homogeneity, although possibly requiring some alterations to pyroprocessing set points.
Andy Hill of Cynosure Partners pointed out that refuse-derived fuel, RDF, has an upper calorific value (CV) limit of around 15MJ/kg, beyond which point the fuel should be considered as SRF. Higher-value SRF exports from the UK are increasing, while lower-value RDF exports have reduced. Andy suggested that SRF will become increasingly commoditised. There has been an increase in thermal value of AF, due to the ban on plastic waste imports into China. Other heavy industrial sectors are increasingly using AF, leading to price pressures on supply. Andy concluded that there is still plenty of opportunity in developing markets to increase the use of AF.
Mark Terrell of Andusia explained how waste markets are evolving in Europe. Mark mentioned that the UK Landfill Tax is now at GBP£91/t, one of the highest rates in the world. He suggested that it is becoming easier to produce a more standardised SRF, with calorific value of higher than 18MJ/kg, size smaller than 20mm and chlorine content of less than 0.8%. A new product is coming onto the market that is effectively a heat-treated SRF that looks like coal and behaves in a similar manner, with CV of around 28MJ/kg, but at a higher cost than SRF.
Stéphane Poellaer next gave a run-down of the most cost-effective measures that can be used to mitigate the negative effects on pyroprocessing of the use of AF. “The limiting factors depend on the kiln type and must be determined for each kiln type. Do not attempt to use AF if the kiln is not fully under control!” stated Stéphane. The main challenges are a higher exhaust gas volume, a higher input of chlorine and changes in kiln behaviour. Typically, cement kilns are limited by the ID kiln fan capacity and use of AF can therefore bring additional challenges. Stéphane suggested that any new AF user should consider feeding material to the calciner first of all, since lower combustion temperatures are required, and the calciner is less sensitive to temperature fluctuations. “Fight against false air!” exhorted Stéphane.
Luigi Di Matteo of Di Matteo Group gave some ideas on best practice on the use of AF. For pre-preparation of fuels, as well as for all aspects of storage, handling, feeding and dosing of co-processing, Di Matteo can provide highly capable pieces of equipment and indeed whole systems for AF use. Di Matteo 4.0 is a new approach to linking all pieces of equipment to ensure that they work much better together.
Moritz Siegfried of SICK AG next spoke on sensor strategies to promote the maximised use of AF. Process gases can be analysed using the SCP3000 gas extraction probe, or using the MCS300P hot wet gas analyser system to keep process gases above the dew point. High levels of circulating alkalis from AF combustion can be detected before they create blockage problems.
Johannes Bartusch of Claudius Peters Projects GmbH next gave some details of a low-pulsation conveyance approach for efficient burner feeding with AF. Instead of using a single large pipe, a number of smaller pipes are used to promote the spontaneous development of higher-efficiency dunes in the conveying lines. Delegates were intrigued and were keen to hear about future research developments.
Matthias Schumacher of Aixergee next gave details of a case study at the Dyckerhoff Lengerich plant in Germany. The calciner at the plant was designed for firing lignite, with a short retention time of 2 - 3 seconds. Elevated CO emissions were encountered when using fluffy calciner RDF and with pelletised RDF: coal-free operation was not possible. The plant wanted to increase the TSR to 100%, at low CO emissions. Unsurprisingly, pelletised AF requires a higher gas velocity for suspension, compared to fluffy fuels. This meant that fluffy fuels were easily suspended and passed through the calciner very quickly. Pelletised particles tended to circulate in the calciner, giving time for a complete burnout, but producing higher CO due to a lack of oxygen as a result of low levels of gas mixing. The engineers at Lengerich suggested the installation of a swirl-inducing pre-combustion chamber at the bottom of the calciner, leading to longer residence times and lower CO production and increased ability to burn cost-efficient fluffy fuels.
Gala dinner and Global CemFuels Awards
The conference dinner took place at the Heineken Brouwerijen in Amsterdam, with the presentation of the Global CemFuels Awards. The outstanding project award went to Lafarge Kujawy, for a project with Lindner Recyclingtech. Alternative fuel user of the year was HeidelbergCement, while supplier of the year was N+P. Innovative technology of the year was the kiln inlet gas analyser system from SICK, George Americanos of Vassiliko Cement was named project manager of the year for a second time, and a joint World Bank/Government of Vietnam effort to use hazardous wastes as AF was named as the outstanding contribution to the promotion of the use of alternative fuels. Andy Hill of Cynosure Partners was named as the Global CemFuels ‘Personality of the Year.’
Second day
On the second day of the conference, Juan José Riesgo of FLSmidth gave details of smart AF solutions for a fast return on investment, giving examples from Cementos Molins, near Barcelona. After an initial AF project in 2011 and a later update in 2014, important lessons were learned. These included that great care must be taken to exclude foreign bodies from the AF; to reduce moisture levels to as low as possible to avoid blockages; that there should be wear-protected bends and large diameter (500 - 700mm) pipes; that fermentation and auto-combustion must be mitigated; and that the system should be built to be able to cope with as many different fuels as possible. Juan detailed a new AF ‘starter kit,’ incorporating an infeed hopper or docking station, rotor-weighfeeder dosing and pneumatic transport, Jetflex Plus burner and ‘very fast’ payback.
Marcus Brew of Untha Shredding Technology next spoke about alternatives to fast-running post-shredders for the production of AF. He suggested that an ideal solution would be a medium-speed machine with a flat-blade cutting system, greater resistance to unshreddable items and faster recovery from any incidents, and with the possibility of the machine being semi-mobile. Marcus gave details of such a machine, at Lancashire Waste Recycling. Using a variety of input materials, LWR produces <30mm SRF main burner fuel and <80mm SRF calciner fuel using a selection of Untha equipment, including an XR XC medium-speed mobile shredder.
Francisco Leme, consultant, next introduced the first of three papers on AF use in South America and in Brazil in particular. Brazil has a cement production capacity of around 100Mt/year, but a TSR of only around 15%: there is an intent to raise the level to that of Portugal (35%), which is likely to involve the use of an additional 2Mt/year of municipal solid waste (MSW). Francisco pointed out that Argentina and Paraguay also have great potential for AF use, although the cost of transport, lack of waste policies and absence of waste treatment facilities are ongoing problems. Tyres, MSW and biomass are the predominant AF types. Average TSR for South America for 2030 is forecast at 22%, but this will require a huge amount of investment and widespread policy support for the use of AF. Critically, these markets are not sold-out, so that there is a strong economic driver for the use of AF.
Delivering a paper co-authored with Daniel Lemarchand, Francisco Leme next presented a ‘road map’ for the Brazilian cement industry for the promotion of the use of AF. Cement industry CO2 emissions only represent about 2% of Brazil’s total, since land use changes, deforestation, and agriculture (primarily cattle ranching) are much larger sectors than in other countries. Francisco suggested that a combination of reducing clinker factor, electrical energy efficiency, AF use and CCS/CCU will reduce the CO2 emissions of cement from 564kg CO2/t of cement in 2014, down to 375kg CO2/t of cement in 2050. Brazil is estimated to produce 300Mt of agricultural biomass each year, of which 170Mt is sugarcane bagasse and straw. To achieve a ‘European’ level of 55% TSR by 2050, huge changes in technical adoption, legislation and habits will have to occur.
The final of the three presentations on South America was given by Sandro Conceição of Cimpor/InterCement, looking at the societal impact of coprocessing. InterCement worked with farming associations and cooperatives in Brazil in order to develop supply sources of quality biomass, while at the same time improving rural incomes and to increase farming sustainability. Sandro reported that the projects were successful on many levels.
The session on AF case studies was started by Neville Roberts, on behalf of N+P Alternative Fuels Ltd, who spoke on the latest developments in the company’s SubCoal product. N+P supplies 1.5Mt/ of alternative fuels, primarily in Europe, primarily in the cement industry, but is also looking outside of Europe and at other industries (steel, electricity, waste to chemicals, lime) as well. SubCoal is a patented technology for the production of pelleted high grade SRF. New developments mean that the pellets will be more easily milled to finer particle sizes. A number of new SubCoal production plants are under development around Europe, including one at Teesside in the UK. The pellets have CV of >20MJ/kg and ash content of less than 12%, even with biomass content of >50%. Neville reiterated that what is important in an alternative fuel is the amount of chlorine per unit of energy, not necessarily the total amount of chlorine.
Con Manias of FCT next spoke about optimised air-entrainment to allow the use of lower quality alternative fuels. Con spoke about the detailed design of burner face plates and how this affects the flame and its radiation profile, as well as the production of NOx and other emissions. Alternative fuels need an optimised burning environment and it has been found that firing with high velocity air and grouped apertures at the burner tip, in an ‘AF boost’ mode, improves air entrainment and heat transfer to the kiln meal, albeit with an increased NOx production of 20 - 25%.
Next Mohammed Hamada Ali Ahmed of El Nahda Cement of Egypt spoke about the use of dried sugar beet pulp as an alternative fuel for the cement industry. The AF has CV of 3.5MJ/kg, ash content of 3% and moisture content of 12%. Around 100,000t/year of the material is available in the environs of the El Nahda cement plant in Upper Egypt, in pelletised form, and which is currently used as animal feed. The cost on the markets is around US$50 - 80/t which is less expensive than the cost of petcoke at the plant.
Jan Tuma of Beumer Group, Czech Republic, next gave a case study of AF systems for RDF at the Dyckerhoff Deuna Zement plant in Germany. The RDF has particle size of less than 60mm, with density 0.08 - 0.3kg/m2 and moisture of around 15%. The overall system has a capacity of 30t/hour, or 375m2/hour.
Ville Hakanperä of BMH and co-author Mr Meng from Handan BBMG (Beijing Building Materials Group) Taihang Cement Ltd next spoke about a zero-waste AF production plant project in China. The cement plant produces 3.5Mt/year and to keep its license to operate it was obliged to take a certain amount of MSW: nothing was allowed to go to landfill, hence the required ‘zero-waste’ concept for the AF production plant. Input into the plant is in the form of MSW and also from mining of the adjacent landfill. Due to the particular nature of Chinese MSW, fully one third of the input feed of the plant is an inert fraction (for example from mixed construction and demolition waste, in the form of bricks and stones) and this material is used as raw material for the cement plant, which is located 20km away from the waste plant. During the initial negotiations, the need for fine screening was ruled out by the Chinese side, but now a fine screening step is being considered to further refine the process. The plant could process more waste if it could be obtained.
Leos Volesky of Schenck Process and Martin Kubant of Cemex Prachovice gave the final presentation, on the importance of accurate alternative fuel dosing. The plant uses many different fuel streams, including RDF and animal meal. The MultiFlex compact closed-unit weighfeeder or MultiDos belt weigh feeder can be used for feeding alternative fuels. Leos concluded the conference by reiterating that “Accurate dosing is required for optimised kiln stability.”
Farewells and prizes
At the conference farewell reception a number of prizes were awarded. Francisco Leme’s paper on AF in Brazil was awarded fourth place in the best presentation awards, while Stéphane Poellaer was in third place. Matthias Schumacher of Aixergee was the runner-up with his paper on the development of a new swirl chamber at the Dyckerhoff Lengerich plant. Con Manias was awarded the prize for the best presentation for his paper on the design of a burner optimised for alternative fuels.
To a strongly positive response, it was announced that the 14th Global CemFuels Conference on alternative fuels for cement and lime will take place in February 2020 in Cyprus, with a confirmed visit to the 6000t/day Vassiliko Cement plant. See you there!
