The IRmadillo for Monitoring Chemical Manufacturing – Specialty, Bulk & Petrochemicals
The chemical process industries encompass many complex and sophisticated chemical and physical processes, reactions and unit operations. Processes may be batch or continuous, high volume or small throughput, commodity or specialised, but in every case there is a need for instrumentation to visualise, control and optimise the process and to improve efficiency and profitability. Basic instrumentation such as flow, temperature, pressure, level and pH sensors is an absolute necessity in this regard. While these instruments are inexpensive and easy to install, the information they provide is basic and does not directly measure the chemical composition of the process. With the advent of Industry 4.0, the bringing together of multiple sources of real-time information for deeper process understanding and optimisation means that more advanced on-line analytical methods are called for.
Analytical experts are used to using high-performance equipment in laboratory settings, (such as NMR, HPLC and reaction control systems with integrated spectrometers), but these are simply not suitable for manufacturing environments. Moreover, many of these instruments are not stable enough to survive the long periods between turnarounds which are a typical feature of continuous processes. So how can the quality of laboratory instruments be taken out onto the plant?
The answer lies in industrial-grade spectrometers, providing real-time spectra that can be analysed to provide concentration traces, batch modelling and descriptive statistics of a campaign. They can be installed on both batch and continuous processes, and work with a large range of different chemicals and process conditions. The most important feature of spectroscopy is not whether it can work or not, but in choosing the right technique for the process.
The Keit IRmadillo family of spectrometers has been developed specifically to bring FTIR out of the laboratory and onto the manufacturing floor. The IRmadillo variants are:
- IRmadilloDiamond: the workhorse of the IRmadillo family, the IRmadilloDiamond comes with a diamond-ATR tipped probe. This gives it a wide range of chemical compatibility, with increased robustness along with scratch resistance. It can be used for a wide range of chemical processes regardless of pH or oxidising nature of the chemistry.
- IRmadillo25H: this model has been specifically designed for high temperatures, and has a working range up to 220°C. The ATR tip is composed of a chalcogenide glass, which gives a full working spectral range of 800 – 3800 cm-1, with no “diamond dead zone” present in the majority of other commercial probes. The glass tip does only have a working pH range of 0 – 9, so is not suitable for alkali processes or strongly oxidising processes.
- IRmadillo25: The globally Ex-certified (C1D2, ATEX, IECEx) original model. Similar to the IRmadillo25H but with a reduced working temperature range and similar limitations on alkali and oxidising processes.
Using the IRmadillo to Monitor Chemical Production
The choice of instrument for your process does depend on the process itself, as well as the types of information that you need to better control and optimise it. In practical terms, this often comes down to a choice between Raman, near infrared (NIR) and FTIR.
There are an almost unlimited number of different chemical reactions in use in the chemical industry, and the vast majority of those can be studied using FTIR. A representative list of processes that have strong features in the infrared spectrum are:
- Transition metal catalysed coupling reactions (i.e. Cativa and Monsanto reactions)
- Addition, elimination and substitution chemical reactions
- Protection and deprotection steps
- Chemical rearrangements
- Hydrogenation and other catalysed reactions
- Purification, distillation and separations
Unit operations such as crystallisation, distillation, absorption and separation also commonly require on-line analytical information in order to be operated safely and efficiently.
Any process that has a change in the chemical functional groups present will have an infrared spectrum, and even slightly changes in chemical (for example reduction of a carbonyl to an alcohol) will have a clear feature that can be used to track reaction progress. Additionally, FTIR can be used as a concentration meter in purification and separation processes, or even to be used as a quality control on reagent loading/unloading – for example, checking water levels in solvent before use to prevent dangerous side reactions from occurring with reactive reagents.
The benefits of on-line analysis compared to lab-based analysis
There are many different reasons why on-line analysis can be considered an improvement over off-line laboratory analysis. Here are three main benefits from using the IRmadillo compared to off-line sampling and analysis:
- Safety: Some chemicals (for example, cyanides due to toxicity, or epoxides due to high reactivity and pyrophoric tendencies) cannot be handled safely. Taking samples off-line from pipelines or railcars is not practical or safe, and needs to be avoided as much as practical.
- Short-lived chemicals: Some chemicals (for example free radicals or reactive intermediates) can be very short lived, and almost impossible to collect and bring to a laboratory for analysis. In this case only an on-line measurement allows detection and monitoring of the intermediates.
- Real-time fine process control: Real-time process control can only be achieved with a real-time measurement. By the time a laboratory measurement has reported its result to the control room it is entirely possible that the process is completely different, and the result is no longer representative.
What about other instruments – NIR, Raman, FTIR and refractometers?
- Raman spectroscopy is similar to the FTIR that drives the IRmadillo’s process monitoring, but it can be very strongly and negatively affected by particles and bubbles in the solution, as well as showing strong fluorescence in many cases. Raman is a good tool for measuring some specific applications – for example, carbon fibre growth – but can have challenges in highly polarised chemistry.
- Near infrared (NIR) technologies provide much less specific information than FTIR, however they can also be very cost-effective instruments. So even though they can give less specific and accurate results compared to an FTIR or Raman, they may be good enough for some situations.
- Standard FTIR instruments contain delicately balanced optics that are highly susceptible to vibration, along with fragile fibre-optic cables making the use of standard FTIRs directly in manufacturing conditions a real challenge.
- Refractometers are cost-effective measurements for simple mixtures with very good process control already. Refractometers work very well measuring one component in another component, but cannot cope with complicated mixtures or a change in temperature (any temperature variation over ± 2°C can cause measurement problems for refractometers).
Chemical Production FAQs
What sort of sample handling or conditioning system do I need?
The IRmadillo was designed for ease of use, so in many cases does not require any sample conditioning or specific handling. The section above specifies the operating conditions of the various models. If you process lies outside of these (for example, a high temperature alkali process) then some sample conditioning may be required – Keit will work with you to establish a solution.
My process is exposed to the weather, hot and cold temperatures – how does the IRmadillo cope?
The IRmadillo was originally developed for the petrochemicals and oil and gas industries – so it can take a beating. It has an ambient temperature range of -20°C to 55°C so temperature variations aren’t a problem. It also has an IP65 rating meaning it doesn’t mind whatever the weather throws at it.
My processes are very dirty – how will your probe cope with fouling and scale?
Keit is also currently developing an in-situ descaling system for other installation sites, so you can install the instrument then walk away, knowing it will stop the build-up of scale or other fouling. What’s more, the instrument checks every scan it takes for quality, and can be programmed to alert you if it detects a build-up for manual cleaning if something went very much out of specification on plant.
The IRmadillo for Monitoring Chemical Processes
If you purchase the IRmadillo for monitoring chemical processes you will receive:
- IRmadillo process analyser
- Interface and mounting accessories to integrate with your process (following a consultation with your engineering team)
- IRmadillo controller PC
- Calibration services
- Ongoing technical and recalibration support (as per your warranty or maintenance contract)
If you like the sound of this, please contact us for more information. We can arrange a trial installation on your plant for several months so you can see you yourself just what the IRmadillo can do.