Combustion is an important part of the refining industry’s ‘Smorgasbord of Measurements’. Boilers, heaters, and furnaces all generate heat and power by combusting hydrocarbons. As a consequence of the chemical reactions of a combustion and the objectives to maximise efficiency and reduce nitrogen oxide (NOX) emissions, oxygen (O2) concentration measurements are used to control excess air to the combustion zone. An additional measurement of carbon monoxide (CO) can provide a feedback on the O2-set point as well as being used to monitor CO breakthroughs to avoid fuel rich operations.
Several different technologies were developed over time to perform combustion optimisation, and tunable diode laser absorption spectroscopy (TDLAS) has proven to be an excellent choice due to its inherent advantages. TDLAS is based on evaluating a recorded absorption spectrum; the latter includes one or more absorption lines of the gas that is to be measured. Recent advances in TDLAS, and especially the way a spectrum is analysed, has opened new opportunities and added functionality to combustion analysers.
This article will discuss a new signal processing approach that helps extract more information than before from the acquired spectrum. The approach has been designed to help create a new path forward for smart combustion analysers and enables an evolution of simple combustion analysis towards a combined process optimisation and safety instrument.
Gas analysers based on TDLAS have been used for many industrial process control and emission monitoring applications and are well-accepted throughout multiple industries. The advantages of performing measurements directly in the process (in situ) include fast response, high selectivity and high sensitivity, which makes efficient process control possible. Furthermore, in situ measurements require little maintenance and thus lower operational expenditures...
Written by Dr Peter Geiser, Dr Viacheslav Avetisov, Dr Junyang Wang and Larry E. Sieker, NEO Monitors, Norway.
Read the article online at: https://www.hydrocarbonengineering.com/special-reports/24122019/smart-combustion-analysis/