If you’re in Minneapolis this week for the Carbon Capture & Storage Summit, make sure to catch Emerson’s Lara Petrishchev’s presentation, Instrumentation Technologies to Address Carbon Capture Challenges. Let me highlight a few points if you can’t make it.
Lara will open by showing a typical carbon dioxide (CO2) capture process in hydrogen production.
The flue gas from the reformer is cooled and desulfurized during pre-treatment. After pre-treatment, the flue gas contacts a solvent in an absorber to absorb the CO2; the rich solvent is then gasified with steam and fed into a stripper where the CO2 is extracted. The CO2-free solvent is then cooled and recirculated to the absorber. A diagram of this process is shown below. Lara shares some challenges with the CO2-capturing amine process.
Some ways to address these challenges include using Micro Motion™ Density Meters to infer lean amine quality. These instruments help manage the amine make-up rate to achieve the desired CO2 capture rate at the lowest cost and reduce the manual sampling required.
In the case of an absorber, the gas and liquid phases are intentionally brought into contact, which can create turbulent flow conditions. This turbulence can cause mixing at the interface, which can blur the distinction between phases and make it difficult for level sensors to detect a clear interface. The Rosemount™ 5300 Level Transmitter – Guided Wave Radar helps ensure the absorber column’s safe operation, reduces calibration maintenance costs and increases product throughput with more reliable level measurements.
Water usage and quality are other challenges since large amounts of water are used in the carbon capture process for cooling and condensation processes. Therefore, a Rosemount Magnetic Flow Meter combined with Rosemount 3900 pH/ORP and 400 Conductivity sensors can assist with water management and energy consumption by preventing scaling and fouling of equipment through water quality assessments.
The carbonic acid associated with this process creates corrosion conditions. The Rosemount Wireless Permasense ET210 Corrosion and Erosion Monitoring System continuously monitors pipe wall thickness and detects the impact of corrosion and erosion.
Heat exchangers are another source of potential inefficiencies through fouling. The Plantweb Insight™ Air Cooled Heat Exchanger Application, combined with wireless devices such as the Rosemount 848T Temperature Transmitter, provides heat duty monitoring and cleaning recommendations to maintain high-efficiency performance.
To ensure an adequate steam supply to heat the amine solvent and extract CO2 efficiently, measuring the steam’s mass to determine the energy content is critical. Temperature and pressure compensation with the Rosemount 3051S MultiVariable™ Compensated DP flow measurement and the Rosemount 8800 MultiVariable Vortex Flow Meter provide steam mass flow measurement.
Adjusting the temperature, pressure, and steam-to-carbon ratio can help maximize the conversion of methane to hydrogen and minimize unreacted methane. Undetected high levels of unreacted methane are an indicator of poor reformer efficiency. The Rosemount X-STREAM Enhanced XEFD Continuous Gas Analyzer is well-suited to make the CH4, CO, and CO2 measurements using NDIR (non-dispersive infrared) photometric detectors to improve reformer efficiency.
Measuring the flow and composition of the flue gas in this process enables improved CO2 balance. For example, the Rosemount Annubar™ Flow Meter Series accurately measures flue gas flow rates with a k-factor correction to evaluate the actual flow rate.
Another challenge is CO2 transportation. For example, when CO2 is transported via a pipeline in a dense/supercritical phase. Accurate density measurement is very difficult due to the phase instability. Due to advanced phase measurement capabilities, Micro Motion Coriolis Flowmeters can accurately measure fluids in a supercritical state.
In addition, trace impurities in the CO2 must be controlled to ensure pipeline integrity and contractual requirements are met. A wide variety of Rosemount Continuous Gas Analyzers can be deployed to fit the requirements of the carbon capture application.
Whether or not you can join Lara’s presentation, make sure to follow many of the links above to learn more about the instrumentation to help you drive greater carbon capture performance.