The 66th IEEE-IAS/PCA Cement Conference and Exhibition 2024 reached new heights in Denver, USA, with a record 1206 attendees to the annual meeting that combined training, a conference, an exhibition and a visit to GCC’s Pueblo plant in Colorado.
The 66th IEEE-IAS/PCA Cement Conference and Exhibition 2024 attracted an audience from 29 countries and representatives from 29 cement companies, according to Local Chair, Jonathan Dennis.
Brian Keefe, Bridge Gap’s managing director, opened the conference proceedings ahead of two days of conference presentations under this year’s theme of ‘Advancing technologies and practices that minimise the impact of cement manufacturing’.
This year’s keynote addresses included a presentation given by former baseball pitcher and motivational speaker Jim Abbott who played for the Cleveland Indians, Los Angeles Angels and the 1988 US Gold medal Olympic team.
In his keynote presentation on the second day of the conference, Dr Avi Shultz, director of the Department of Energy (DoE) Industrial Efficiency and Decarbonization Office (IEDO), warned that 60 per cent of the CO2 to be collected from cement by 2030 was still not achievable with current technologies. The aim is now to get resources to the industry fast.
In FY23 the IEDO 's budget includes US$131m for energy and emissions intensive industries, US$90.5m on cross-sector decarbonisation technologies and US$45m for technical assistance and workforce development. In FY24 the cross-sector will be funded US$38m and the FY24 incentives for the energy and emissions intensive industries are set at US$83m.
In addition, the CCUS Decarbonisation Action Plan will set metrics and target the highest-level strategies for decarbonisation.
CCUS and its challenges: up for debate?
While industry is driving the need for CCUS development and implementation to achieve its net-zero goals, governments are now supporting this with funding.
The push for CCUS implementation was also highlighted in the Environmental, Energy and Sustainability panel which included a discussion between Salvatore Gollo and Ted Hornus of Redecam, Jerry Hunt of Lhoist, Gary LeMaire of Worley Group, Aswin Patni of Lechler Inc, Travis Reynolds of Lhoist and Ian Saratovsky. Gary LeMair talked about the market readiness for CCUS and the barriers such as the industry’s continued reliance on coal. He advised turndown requirements with modes of operation, duct routing, quenching and pretreatment for flue gases and the need for heat and power with a combined heat and power unit.
Julia Attwood of Bloomberg moderated a CCUS panel session with Andrew Baxter of Sustainable Energy Solutions, Floren Gautier of Air Liquide, Kevin Louzze of Sargant and Lundy and Greg Ronczka of Heidelberg Materials North America. Kevin Louzze said the number one challenge is the need for clean power for CCUS. Floren Gautier explained this is why offshore wind power is being looked at first in Europe for several projects.
Meanwhile, Andrew Baxter added that air and water permitting was also going to be a challenge, as well as the cost of transport and storage of CO2 once it had been captured. For some areas in the USA, like the Gulf region in the south, it was suggested it will be business as usual despite the clamour for CCUS because there are still plentiful resources of gas and oil available. Areas where CCUS will be difficult is in highly populated areas like northeast USA as they don’t have the pipe structure where they do in Texas, Florida and the Midwest.
Given these challenges, Greg Ronczka explained why the Mitchell plant was selected as Heidelberg Materials’ first CCUS project in the USA with its new kiln line investment, existing storage basin and abundant water resources.
The issue of power generation was also addressed by several speakers, who provided a wide-ranging set of presentations. Max Tschurtschenthaler of ABB Schweiz AG discussed how to kickstart a clean era in industrial high-temperature heating. Jim Allen of Martin Marietta, Marc Elliott and Henry Gonzalez of Eaton Corporation and Alan Bond of Panduit focussed on plant operations with their paper on ‘Prevention through design-reducing risk in absence of voltage distribution and control equipment.’
Furthermore, as carbon capture and sequestration (CCS) is a water intensive process, water recovery and reclaim will be important for the cement sector as it introduces this new technology post combustion for kiln flue gas scrubbing. The option for zero liquid discharge is particularly complex for wet limestone scrubbing and may require removal of trace elements. However, Brad Buecker of Buecker & Associates LLC and Syed Suhail Akhtar of Holcim were on hand to provide an overview of water reuse and sustainability methods.
Senior industry consultant Xavier d’Hubert and Fabien Michel, Voltigital’s managing director, delved into CO2 utilisation with a paper on ‘Some CO2 utilisation processing technologies of interest to the cement industry’. This paper looked at different CO2 utilisation and processing technologies, including accelerated mineralisation/carbonation, CO2 to fuels and catalysts, electrolyses and plasma technology. They concluded that the industry would benefit from focussing on the energy requirements for these technologies, the scalability, efficiency targets and the level of CO2 purity required. He suggested that accelerated mineralisation will not be the prime focus for cement companies, especially before 2030 as many other decarbonisation pathways should be implemented first.
The shift to low-carbon cements and SCMs
In an effort to decarbonise the building materials sector, the US cement industry is committed to shift its production away from carbon-intensive cement types. US cement plants are now producing blended cements.
Portland limestone cement (PLC) is now available in all 50 US states, according to PCA President and CEO, Mike Ireland. Moreover, approximately 4Mta of PLC have been produced in the USA in 2024.
In addition, there is also increasing interest in the use of supplementary cementitious materials (SCMs) – as reflected in several presentations. Dr Luc Rudowski of thyssenkrupp Polysius and Dr Hendrik Möller of Schwenk Zement GmbH & Co highlighted the mechano-chemical activation (MCA) process as an efficient process to activate any combination of clay minerals even with kaolinite-poor clays in their presentation ‘Activated clay can be produced as supplementary cementitious material through different processes – promising news for the cement industry’s decarbonisation’. Strength and heat of hydration can be adjusted by MCA as a function of the level of mechanical energy applied. For workability, MCA allows for a better flow and a significant reduction in water demand, according to them. To move the development of this process into the next stage, Thyssenkrupp Polysius and Schwenk Zement are now building an industrial demonstration plant to produce activated clay using meca-clay technology.
SCMs were also the subject of an environmental, energy and sustainability panel discussion on ‘Which is the best supplementary cementitious material and why? Tom Adams, director of the American Coal Ash Association, Joe Thomas, president of the Natural Pozzolan Association, and Steve Butler, product development director at Arcosa Speciality Materials updated delegates on the growing opportunities for SCM use in cement.??Tom Adams started with a look at coal, ‘As an SCM for today and tomorrow’. With coal plants retiring at an increasing rate, it may look like there is not much potential, but these are the smaller plants that are unable to be retrofitted. Meanwhile, demand for SCMs is increasing in the USA. The fly ash usage grew from 44.5 per cent in 2008 to 62.25 per cent in 2022. There are also still 300 years’ worth of coal resource left in the ground. The distinction between fly ash and bottom ash has gone now and it is simply called coal ash. Some 36t of coal ash was produced in 2022 and 11.5Mt is used in concrete mixes in the USA. Moreover, 50 per cent of coal ash is taken by the gypsum wallboard industry and their demand could cater for 65-70 per cent of the annual coal ash volume. Harvesting buried reserves of coal ash is now big business. By 2024, 4Mt of harvested coal ash will be used in concrete in the US, up from 1.8Mt harvested in 2022.
Joe Thomas talked about raw natural pozzolans as SCMs, stating that clays and shales and slates are now being harvested in larger volumes as a valuable SCM resource.??Steve Butler presented the case for shale clay and slate as SCMs as an OPC replacement in clinker. A favourable point of using these materials is that they can be co-grinded with clinker, saving power. The reserves are mainly located in the east and Midwest in California. The main barriers are storage requirements and transportation, but the water requirement for processing is low.
Prized presentations
Sam Bloomfield of Drake Cement and Karsten Brink Floor of FLO2R presented the conference’s winning paper, ‘User perspectives and experiences with a new type of kiln inlet gas analysis probe system’. Drake Cement suffered a lack of reliable inlet gas analysis leading to missed fuel consumption targets, over-burned clinker and process stops. The FLO2R kiln gas inlet system uses electrochemical oxygen analysis and infrared CO, NO, CH4 and SO2 analysers. The essential advantage of this equipment was that the probe’s innovative cleaning method removed any build-ups with two air blasters enabling precise, continuous and consistent data for plant operators.
The second prize went to "Operational strategies and equipment upgrades fro meeting cement kiln particulate emissions limits with existing electrostatic precipitators' by Ivan Sretenovic of Process Barron and Paul Ford of Redkoh.
In their paper, awarded third place, Tahir Abbas and Michalis Akritopoulos of Cinar and Syed Suhail Akhtar of Holcim discussed the advantages of burning green NH3 in a cement kiln. Dr Abbas noted that full-scale, on-site green hydrogen production is difficult resulting in partial generation with a small-scale electrolyser and co-firing with imported green NH3. However, vast NH3 transport infrastructures exist, while the higher NOx emission potential of NH3 can be addressed through designing fuel-mix and optimum NBR aerodynamics.
The authors of these papers received their awards during the Awards Banquet on the conference’s final night, before delegates set off the following day to visit the GCC’s Pueblo cement plant (see also ICR’s June issue).
Looking ahead
Ed Sullivan, PCA’s vice chairman and chief economist, treated attendees to his outlook for the US economy and cement consumption. He stated that it was the first time in 14 years that economic growth had been in decline and that the Federal Reserve was still trying to get back to its two per cent inflationary target. As a result, he forecasts US cement consumption growth of just 1.1 per cent this year, accelerating to 2.8 per cent in 2025 before stabilising at 2.6 per cent in 2026-27. (The full US cement consumption forecast was published in ICR April 2024.)
The next IEEE-IAS/PCA Cement Conference and Exhibition will be held in Birmingham, Alabama, USA, between 4-8 May 2025.
