Earlier this month, the Portland Cement Association, an industry trade group representing some of the world’s leading cement manufacturers, released their Roadmap to Carbon Neutrality – a 30-year initiative to achieve carbon neutrality by 2050. It’s a timely effort by an industry that recognizes the need for change. After water, cement is the most-consumed material on earth. Our modern society wouldn’t be possible without it, with an average of 3 tons of concrete used per person every year.
Cement manufacturing is an energy-intensive process that is responsible for as much as 5% of the world’s carbon emissions, and as the demand for cement has grown, so have efforts to reduce the industry’s carbon footprint.
There has been a significant push to find alternatives to fossil fuels in the cement industry, with US-based cement plants now meeting over 15% of their energy consumption needs with alternative energy sources. While these efforts have helped cement plants meet sustainability targets and regulatory standards, they’ve also created significant challenges for some operations.
Switching from conventional fossil fuels to alternative energy sources introduces more variability into a complex process and can lead to buildup, blockages, and other production and storage issues. As cement plants continue the transition to alternative fuels, it’s critical that they equip themselves with effective solutions to mitigate these production challenges and remain economically viable.
Cementing a Greener Future with Alternative Fuels
Like many industries adapting to meet consumer and regulatory demands, cement producers have been embracing more environmentally-conscious production, storage, and waste disposal methods in an ever-changing industry landscape. With rising awareness surrounding the cost and sustainability of conventional fossil fuels like the coal, oil, and natural gas traditionally used for cement production, cement industry innovators have been seeking out alternative fuel sources and processes to reduce CO2 emissions.
Alternative fuel sources can come in solid, liquid, or gaseous form. Some fuel alternatives being utilized or pursued at present include:
- Tire-derived fuel
- Pistachio hulls
- Timber waste
- Refuse-derived fuel
- Rice husks
- Animal bone meal
- Petroleum coke
- Sewage sludge
- Palm kernel oil
- Landfill gas
- Lubricants, solvents, & other industrial chemical waste
There can be numerous advantages to co-processing alternative fuels in cement production, from the environmental benefits to reduced energy costs for the plant. However, these projects demand careful planning and expertise, and can require major equipment upgrades throughout the production line, including:
- Fuel milling, conditioning, storage, & feeding systems
- Mixing chambers
- Pre-heaters & calcination systems
- Chlorine bypass systems
- Rotary kiln burners
- Buildup removal systems
Common Production Challenges
There are a number of issues and limitations to consider when evaluating alternative fuel sources for the cement industry
#1. Rotary Kiln Flame Formation
Rotary kilns typically make use of a multiple channel burner or other equipment that allows various alternative fuels with different physical properties to be fed into the kiln during operation. Compared to conventional fuels, alternative fuels can have lower heating values, larger particle sizes, or higher water content, factors that can affect the combustion process. If these fuels result in a longer flame length or lower flame temperature, it can negatively impact clinker reactions or reduce the life of the refractory walls or other system components.
#2. Altered Cement Chemistry
When alternative fuels are burned in a rotary kiln, the carbon and organic elements are mostly burned out, while the inorganic elements that remain are often incorporated into the cement clinker. For many alternative fuel sources, the effect of these impurities on the final product ranges from insignificant to beneficial. However, some fuel sources, such as tires or bone meal, have the potential to input enough phosphorus, zinc, or other compounds to disrupt clinker formation and reduce the quality of the finished cement.
#3. Buildup & Blockages
Other impurities in alternative fuel sources – particularly sodium, potassium, sulphur, and chlorine – can promote unwanted chemical reactions and have a destabilizing effect on plant operations. These issues include material buildup and snowman formations in calciner cyclones, rotary kiln ring formations, unburnt carbon deposits, and various buildup and blockages throughout the plant. To continue operating efficiently, cement plants must incorporate thorough buildup removal and cleaning activities into their production processes on a regular schedule.
Surefire Solutions to Cement Production Challenges
Driven by sustainability initiatives and tightening regulatory mandates, the use of alternative fuels by cement plants around the world continues to rise. Increasingly, cement production facilities are turning to specialized equipment designed to help address their unique challenges.
#1. Dual Impact BinWhip
The Dual Impact BinWhip was designed to address the unmet needs of the cement industry. It’s been proven effective in cement plants around the world, rapidly clearing raw material and finished cement buildup from bins, silos, and storage vessels without the need for hazardous confined space entry. Unlike the underpowered air-driven systems of the past, the Dual Impact BinWhip employs a hydraulically-powered whiphead with two sets of chains rotating in opposite directions to rip through rock-hard buildup and restore storage systems to full capacity.
#2. Cardox CO2 Blaster
Most cement plants across North America make use of a Cardox CO2 blasting system to safely dislodge buildup inside their preheater tower risers and cyclones, kilns, coolers, and storage vessels. To deploy the system, cement workers charge a reusable Cardox tube with liquid carbon dioxide, then embed it in hardened material or lock it into a base socket that has been installed in a buildup-prone area along the production line. The system is then fired from a safe distance, releasing a blast of carbon dioxide at up to 34,000 psi with the power to fracture hardened cement, coal, and other rock-hard materials without creating a high-velocity shock wave that could damage production equipment.
Because it does not present a fire hazard, Cardox is widely used in locations where dust or other hazardous combustible materials are present. The high-strength steel alloy tube can even be safely fired in hot kilns where the internal temperature can be up to 2000 degrees Fahrenheit. Since it can take days to shut down, cool, and reheat an industrial kiln system, Cardox provides a dramatically more efficient solution that can deliver massive cost savings to cement plants.
#3. Professional Cleaning Services
Sometimes cement plants may have immediate buildup removal needs, but aren’t currently in a position to invest the time or resources needed to purchase and operate their own cleaning equipment. These companies frequently turn to professional cleaning services like TeamPneumat for routine or emergency buildup and blockage removal in their precalciner towers, kilns, coolers, or bins. This gives cement plants access to bulk flow specialists with years of experience dealing with cement plant issues of all types, a full arsenal of cement plant cleaning equipment, and allows their own team members to remain focused on essential production activities.
Partnering With Cement Production Equipment & Cleaning Experts
The cement industry leaders working to bring down CO2 emissions and protect the environment know that the road to carbon neutrality won’t be easy, but they’re committed to solving whatever challenges lay ahead. The mining, production, distribution, use, and disposal of cement represents a complex interconnected value chain. Meeting the industry’s ambitious sustainability goals will require creative partnerships between government agencies, non-profits, academic institutions, the building sector, and innovative equipment manufacturers.
For over 4 decades, Pneumat Systems has been proud to help meet the needs of cement manufacturers with unique specialized equipment designed to address their toughest bulk flow problems. As the drive to adopt alternative fuel systems and other new technologies gives rise to new challenges and opportunities, Pneumat’s Dual Impact BinWhip, BinDrill, Cardox CO2 Blaster, and TeamPneumat cleaning crews will continue adapting to meet the needs of cement industry professionals into the future.
Contact Pneumat today to learn how our proven buildup and blockage removal solutions can help your plant run more efficiently as we build a safer and greener future, together.