Virtual IEEE-IAS/PCA event

The 63rd IEEE-IAS/PCA Cement Industry Technical Conference was held on 24-28 May 2021 as a virtual event, consisting of training workshops, technical conference, international exhibition and three plant tours. ICR, a media sponsor for the event, took part in the virtual conference and followed the presentations remotely to deliver this report.

Chris Macey, CIC chair, opened the main conference sessions on 25 May 2021, advising that the Cement Industry Committee (CIC) had prepared the information for everyone’s betterment. “Our goal has always been for you to leave this conference with ideas and concepts to reduce your costs, improve your competitiveness, understand your market better and affect your company’s sustainability,” he said.

Mark Mueller, conference chair and KHD parts and services manager, noted that the IEEE-IAS/PCA had chosen a virtual venue because of an abundance of caution during these improving but still very uncertain times. “The CIC strives to continue every year to deliver the latest technologies to the forefront, deliver hard-hitting economic forecasts, and continues with environmental workshops to help us all be better stewards of this planet we call home,” he said. “The goal of carbon neutrality for the cement industry is the most critical driver in our industry’s future,” he added.

Nate Murphy, CIC technical sessions vice chair, was responsible for the 30 technical presentations delivered by industry-leading experts and driven by six working groups.

PCA’s roadmap to carbon neutrality by 2050

Keynote speaker, Rick Bohan, PCA sustainability vice president, focussed on plans to develop a roadmap to carbon neutrality by 2050. He advocated that the roadmap would be a commitment to the entire value chain from clinker, cement and ready-mix to the built environment. Rather than just cut cement production, Mr Bohan was keen to stress that: “Cement and concrete are a solution, not a problem to global warming.”

He also underlined that waste had to be reduced and long-term optimisation of processes are required. Introducing raw materials that had already been calcined would lower emissions by 10 per cent at the plant and double the level of today. Efficiency gains from 3.84 to 2.76mBtu would be required, along with switching to 50 per cent alternative fuel usage, greener transportation fuels, and carbon capture, utilisation and storage (CCUS) technology. While there are CCUS projects already underway in the US and the rest of the world, more infrastructure for pipelines and ways of storing and utilising carbon will be required.

The clinker ratio in cement would be reduced from 0.91 to 0.75 and there would need to be universal acceptance of Portland limestone and blended cements.

Furthermore, it would be important to optimise concrete to make a 26 per cent improvement by 2050 or one per cent every year to 2050, Mr Bohan noted. Currently, US plants operate at 229kg of CO₂/yd³ and this would come down to ~90kg of CO₂/yd³.

Improving construction of the built environment by 30 per cent by 2050 needs closer examination of the CO₂ footprint of cement in the areas of design, construction use and end of life. Concrete can also be improved as a carbon sink.

“It will need everyone’s input to succeed in reaching carbon neutrality by 2050 or before – everyone in the value chain,” said Mr Bohan. The roadmap is due to be published by the end of September or the beginning of October.

Argos Martinsburg plant tour

Among the multiple plant tours was an overview of Argos’ Martinsburg cement works based in West Virginia. The facility operates a Loesche 400tph vertical raw mill, coal mill and an alkaline bypass system. Coal is the main fuel, but a recent investment means solid recovered fuel (SRF)  is also used for fuel savings and a reduced carbon footprint. The SRF is graded at 7tph and is formed from residential waste and waste from the plant itself. A 10 per cent coal substitution rate is currently being achieved, but the goal is to reach 20 per cent.

The Martinsburg facility produces several types of cement, including Type II LA cement, Type III L cement, masonry Type S and M cement. Some 45 per cent of product is shipped in bulk by rail cars and 55 per cent goes out through bulk tanker trucks.

Taking to the air

The second day included an automation paper by Adam Chapman of CalPortland on ‘Applying unmanned aerial vehicle technology in the cement and mining industry’. Photogrammetry is the process undertaken by drones, capturing photos along a physical path and putting them through a software programme for a 3D recreation.

Stockpile inventory and typography data is the main object of the flights for CalPortland. Orthomosaic photos are created from 700 images and are helpful for site planning. Digital terrain models and digital surface models can then be overlayed to give elevation information. Large flights cost U$10,000 and smaller flights half of this price. Operational savings, data control, safety and time savings are all benefits of using drones.

Lehigh Hanson Redding – making a product from kiln exhaust gases

Lehigh Hanson’s Redding plant in California, the focus of another plant tour,  is working with Fortera Inc to reduce GHG emissions from the kiln stack to convert them into a cementitious material for the manufacture of high-quality concrete. The project uses limestone and makes a reactive form of calcium carbonate that has cementitious properties.

This approach uses existing infrastructure in the Portland cement industry. Limestone is processed through the kiln to create lime, but the recarb™ process uses the lime to recapture the CO₂ to make Fortera cement. This results in the 44 per cent of the weight of CO₂ that would typically be lost from the limestone being recaptured as product. The product is not only calcium carbonate, it is reactive and adds to the cement properties. Limestone is the only raw material required and calcinates at 950˚C, allowing lower energy costs than when manufacturing OPC. There are also over 60 per cent savings in CO₂ reduction.

The calcium carbonate is made reactive by activating calcite into vaterite – a reactive polymorph of calcium carbonate. Vaterite is a water-activated SCM that leads to higher clinker substitution with its particle packing density and high surface area. Fortera integrates seamlessly with OPC, meeting ASTM regulations, and handles, cures and performs in the same way as OPC.

Green hydrogen and oxygen enrichment

‘Benefits of micro-grids/energy storage and the green hydrogen option’ was presented by Xavier d’Hubert of XDH Energy. Fed by renewable electricity, electrolysers provide oxygen for oxyfuel combustion at a cement plant and hydrogen to combine with the CO₂ from the stack in so-called methanation to provide kerosene for airplane fuel. Oxygen enrichment can be used to reduce flue gas and allow higher production and burning of lower-grade alternative fuels. It also enables higher concentrations of CO₂ in the kiln easier to capture. For every project the location of the plant is critical.

California’s clean air

As part of the panel discussion addressing alternative fuels and raw materials to cap and trade, Steve Walters of Trinity Consultants talked about California’s AB-32 cap and trade programme that began in 2006.

Transport, industry and electricity generation are the main markets targeted for CO₂ emissions. California requires a 40 per cent decline of CO₂e from 431Mt in 2020 to 260Mt of CO₂e by 2030. If companies exceed their allocation, they will need to comply by either reducing production, install pollution controls, purchase pollution credits or buy offsets. Mr Walters said carbon prices will increase, while permit caps will decline through 2031. Auction prices for credits will also increase and carbon prices are expected to reach US$40/t by 2031.

Winning presentations

This year’s winning papers, announced by Richard Schmidt, paper review chair, were:
1. Automation session: ‘Applying unmanned aerial vehicle technology in the cement and mining industry’ by Adam Chapman, CalPortland
2. General practices session: ‘Implementation of studded roll bodies for raw material HPGR grinding system’ by Samira Rashidi and Stefan Diedhofen, thyssenkrupp Industrial Solutions, and Allan Simmons, CalPortland
3. Environmental, energy and sustainability session: ‘TIVACS vacuum shock baghouse technology reinventing baghouses for improved performance and simplified maintenance’ by Luis Castano, IAC International.

Next year’s IEEE-IAS/PCA Technical Cement Industry Conference will be held in Las Vegas on 1-5 May 2022.