The high cost of carbon capture, due to the amount of energy it requires, presents challenges for its widespread adoption by the cement industry. This article explains how advanced automation can improve the energy efficiency of carbon capture, increasing its viability within cement production.
The cement industry is responsible for about 8% of global CO2 emissions, so reducing the carbon footprint of this hard-to-abate sector by implementing carbon capture and storage (CCS) technologies on a commercial scale is vital. However, several key challenges must be addressed if meaningful change is to be achieved, including lowering the operational costs and increasing the efficiency of the energy-intensive carbon capture process.
In an International Cement Review article, ‘Automation Technology for Lower Carbon Capture Costs’, we reveal that according to the International Energy Agency, most carbon capture processes today consume between 10% and 40% of the energy generated for the entire production process. This ratio is called the energy penalty and determines the efficiency of a carbon capture system. As the article explains, it is important that the cement industry:
…develops more energy-efficient capture technologies and uses renewable sources to power capture systems. Operational efficiency gains begin with design considerations, where engineers strategically select materials, operating conditions, process configurations, and equipment to establish cost integrity, ensuring project feasibility and maximising return on investment. Flaws or inadequate equipment selection during this phase can result in inefficiencies and permanent energy losses.
Advanced performance engineering software plays a pivotal role in evaluating the economic feasibility of proposed carbon capture processes well before they are implemented. These tools enable engineers to accurately model complex chemical and thermodynamic systems, identify inefficiencies, estimate energy requirements, assess risk, and proactively address problems. Adjusting variables such as solvent type, concentration, temperature, pressure, and flow conditions can significantly reduce energy requirements and result in a lower energy penalty.
AspenTech’s process simulation software, Aspen Plus®, plays an important role during technical and economic feasibility of carbon capture processes for hard-to-abate industries like the cement industry.
The article explains how digital twin technology enables engineers to further streamline the design and operation of carbon capture systems by leveraging analytical computer models to improve energy efficiency and reduce costs, both before and after a system is brought online. It states:
…Carbon capture digital twins can simulate gas and liquid stream flow through the capture system, allowing engineers to identify optimal conditions for capturing CO2 with minimal energy consumption and obtain guidance for optimal operations as flue gas compositions change with the use of different fuels in the kiln. Digital twin technology also facilitates real-time monitoring and performance comparison, enabling quick detection of deviations or abnormalities indicating energy waste.
We then describe how efficient heat generation and transfer equipment is central to the cost integrity of any facility engaged in carbon capture, and why continuous monitoring and management of this equipment is crucial in minimizing the energy penalty of a carbon capture system. Advancements in wireless technology have made this monitoring more reliable and cost-effective. The article continues:
…High-accuracy sensors, deployed using wireless technology, can improve data collection for heat transfer optimisation. Real-time measurement of differential pressure, flow, and temperature using a single self-diagnostic wireless device further enhances accuracy. Wireless measurement devices help to improve the management of heat transfer equipment, crucial for minimizing the energy penalty of a capture system.
Optimizing performance extends beyond heat exchangers to boilers, pumps, compressors and critical equipment. The article explains how advanced adaptive process control software enhances carbon capture system efficiency across multiple variables by allowing equipment to run closer to operational and safety constraints, minimizing energy use. Energy management information systems consolidate energy performance across many complex assets, enabling operators to prioritize activities for the biggest impact. Pre-configured analytical software tailored for multi-fuel boilers using off gases, waste fuels and biomass further reduces a system’s carbon footprint while increasing steam production capacity and stability.
The article explains that the objective of all carbon capture units is to isolate as much pure CO2 as possible with the least energy consumption. It states:
…Achieving the ideal balance between capture rate and energy cost is where automation holds significant potential. A comprehensive evaluation of factors and a systematic, multi-dimensional approach is required. Rigorous process simulation techniques play a crucial role, aiding operators in understanding the behaviour and performance of their capture system.
Analytical models accurately predict interactions between different components in the CO2 absorption or adsorption process and solvent regeneration process, along with resulting energy requirements. By simulating different operational scenarios and parameters, the impact of varying capture rates on energy consumption and vice versa can be assessed without real-world experimentation. Process simulation, examining regeneration temperatures, pressures, chemical compositions and other variables, can minimize energy requirements while maintaining a satisfactory capture rate.
We next explain how integrated control systems are pivotal for managing capture rates and energy consumption in carbon capture systems. The article continues:
…By continuously monitoring operating conditions, performance metrics, and relevant parameters, such as temperature, pressure, flow rate, and composition, control systems optimise the capture process in real time. They regulate parameters such as adsorbent bed temperature, adsorption pressure, or solvent flow rate to ensure the CO2 capture rate remains within the desired range. This control scheme helps maintain high capture efficiency, minimise energy consumption, and optimise system performance.
The article goes on to describe how advanced process control (APC) software facilitates the integration of the carbon capture system with the existing production process. With the integration between AspenTech’s APC and Emerson’s DeltaV™ distributed control system, the benefits of distributed control system can be expanded to a complete multivariate optimization, thereby optimizing energy usage and load distribution, ensuring efficient resource utilization, and maximizing overall system efficiency. The value of APC extends to new facilities, particularly within the adsorber/absorber unit, leveraging advanced machine learning algorithms to optimize performance.
Finally, the article explains how advanced measurement technology such as density meters and gas analyzers can also contribute significantly to maintaining the ideal capture-to-energy balance. It states:
…Density meters provide crucial information about capturing agent concentration, aiding in controlling solvent regeneration and optimising energy consumption. Continuous gas analysers offer real-time data on chemical composition and CO2 concentration, enabling the control system to regulate heat used for solvent regeneration. These analysers simplify regulatory reporting, aiding operators in making better operational decisions and achieving the desired capture-energy balance. Continuous gas analysis provides real-time data on chemical composition and CO2 concentration, enabling heat used for solvent regeneration to be regulated.
For more information about optimizing the carbon capture process, visit www.Emerson.com/en-us/esg/environmental-sustainability/carbon-capture-storage
