Decarbonisation Technology - November 2021

process reaction reduces the amount of harmful emissions likely to be generated. Gas clean-up and carbon capture Gas analysis plays an important role in gas cleaning, the removal of harmful substances from process gases that might otherwise be emitted by the plant. Typical examples of gas clean-up processes include DeNOx (ammonia slip) treatment, flue gas desulphurisation, and carbon capture and storage (CCS). By capturing and storing CO 2 , the operator ensures it is not released into the atmosphere. This results in a cleaner environment, and allows the CO 2 to be used in other processes. Three different methods exist for CCS: pre- combustion, oxyfuel, and post-combustion CCS. Post-combustion CCS takes place when CO 2 is removed from the flue gas after fossil fuels have been burned. Oxyfuel CCS produces a flue gas

and a fast response to changing conditions. A combustibles sensor can be added easily at modest cost to provide an all-in-one combustion control solution, such as in Servomex’s ServoTough FluegasExact 2700 combustion analyser. Tunable diode laser (TDL) technology provides an even faster measurement, particularly for CO, and gives an average measurement across the measurement path, rather than the result at a single point. However, since TDL sensing is highly specific to the gas being measured, separate Combustion TDL analyser provides a solution for this application, and this can be configured to measure either O 2 or CO. It can also be configured for a joint measurement of CO and CH 4 , providing a rapid-response measurement for safety in natural gas fired heaters and boilers. Gas analysis also supports greater process efficiency in many other applications. An efficient analysers are required for O 2 and CO. Servomex’s ServoTough Laser 3 Plus

consisting almost entirely of CO 2 and steam by reacting the fuel source with almost pure O 2 – this means flue gas can be stored/sequestered without significant pretreatment. Both these methods can be used in new plants, or retrofitted to existing ones. A third method, pre-combustion CCS, is performed before burning the fuel, and converts the fuel into a mixture of hydrogen and CO 2 . This is difficult to retrofit, so is better for newly built facilities. Whichever method is used, the captured CO 2 is then compressed into a liquid and transported for storage. As countries look to meet their responsibilities under Paris Agreement carbon reduction targets, the use of industrial-level CCS is likely to grow significantly, as is the requirement for accurate gas analysis to support the processes. Servomex’s ServoTough SpectraExact 2500 photometric analyser is ideally suited to this application. It is capable of single or multi-component gas monitoring in corrosive, toxic or flammable streams, using infrared and gas filter correlation technologies to