How to improve industrial processes through continuous monitoring?

Continuous monitoring has evolved from being a tool for cost savings and regulatory compliance to becoming the cornerstone of industrial process optimisation.

Implementing systems that analyse the degree of compliance of an industrial process in real time enables early detection of deviations and, consequently, transforms operational data into strategic decisions that significantly improve production quality, achieve operational excellence and promote sustainability.

What involves continuous monitoring of industrial processes?

Continuous monitoring of industrial processes essentially consists of a set of technologies and methodologies implemented to observe, measure and oversee, in real time, the behaviour of critical variables within the production environment. In practice, it involves equipping facilities with an intelligent system that continuously assesses the degree to which each operation is being carried out in accordance with specifications.

To achieve this, a network of industrial process sensors and analysers is deployed to collect data continuously directly on-site, even in hostile environments or on older machinery. These systems integrate computing, storage and communication capabilities to monitor physical processes and environmental variables in real time.

Critical Control Points (CCPs) in industrial processes

Within industrial processes, there are stages, variables or parameters which, if not properly monitored and adjusted, compromise the plant’s efficiency, safety or profitability. Monitoring these correctly enables the industry to maximise its Overall Equipment Effectiveness (OEE) and drastically minimise operating costs.

The most critical parameters that directly impact operations include:

Process gas monitoring

The composition and concentration of industrial gases determine the kinetics of chemical reactions and the safety of facilities. The deployment of advanced analytical technologies is essential for optimising each process according to the gas or combination of gases involved.

Many gases or gas mixtures are involved in production processes, but among the most common are:

• Oxygen (O2): oxygen measurement is essential for controlling combustion in industrial boilers and furnaces. Zirconium oxide sensors are used to adjust the air-fuel mixture to maximise thermal efficiency. Furthermore, it is critical in biological processes such as aeration in wastewater treatment plants (WWTPs) or in pharmaceutical bioreactors.
• Hydrogen (H2): its continuous monitoring is vital throughout the value chain. It is a critical factor in steam methane reforming (SMR) processes at HyCO plants and in generation via electrolysers (PEM or alkaline). Continuous H2 monitoring ensures the purity of the gas produced, prevents leaks during storage and optimises the energy efficiency of the electrolysis process.
• Nitrogen (N2): nitrogen is widely used as a carrier or inerting gas in the chemical, pharmaceutical and food industries. Monitoring the purity and moisture content of nitrogen ensures that no unwanted oxidation reactions or explosions occur and maintains controlled atmospheres.
• Carbon Dioxide (CO2): CO2 is present both in chemical synthesis and as a combustion by-product. Its comprehensive analysis using NDIR technology identifies the gas without cross-interference, enabling the fine-tuning of reaction conditions, reducing the carbon footprint and preventing fuel wastage in heat generation systems.
• Mixtures of CO2 and methane (CH4): mixtures of CO2 and CH4 form the operational heart of biogas plants and anaerobic digestion systems. Methane is the energy carrier, whilst CO2 acts as a diluent that reduces the gas’s value. Continuously monitoring this mixture with dual sensors ensures the highest quality of biomethane, optimises microbial activity and guarantees the plant’s profitability.
• Ammonia (NH3): this gas is essential in fertiliser production, in large industrial refrigeration circuits and in catalytic reduction (DeNOx) systems for chimneys. Continuous measurement and control prevent the dreaded ‘ammonia slips’ (ammonia slip), protecting workers from its high toxicity, preventing accelerated corrosion of the facilities and ensuring compliance with environmental regulations.
• Sulphur dioxide (SO2) and acid gases (HCl and HF): in industry (incinerators, cement plants or thermal power stations), SO2, HCl and HF are removed using abatement technologies known as scrubbers (wet, dry or semi-dry). To neutralise these three gases, alkaline reagents such as sodium bicarbonate or hydrated lime are injected. Continuous monitoring allows the plant to calculate the total acid load and optimise the exact dosage of the reagent, avoiding the extra cost of using more alkali than necessary.
• Formaldehyde (CH2O): formaldehyde is a highly toxic and carcinogenic volatile organic compound involved in the manufacture of wood-based panels (MDF, chipboard), the production of resins and adhesives, and the textile industry; its continuous monitoring has become critically important following the recent entry into force of European Regulation (EU) 2023/1464.
• Propane (C3H8) and combustible gases: Propane is a liquefied hydrocarbon widely used as an industrial fuel in boilers and industrial furnaces or in metal heat treatment processes, amongst others. The installation of continuous detector networks configured to measure the Lower Explosive Limit (LEL) prevents the formation of explosive atmospheres (ATEX) as well as preventing direct fuel loss.
• Water vapour (H2O): although water vapour is not a polluting gas, its continuous measurement in the gaseous state (absolute humidity and dew point) is one of the most critical variables for quality control and equipment protection in compressed air networks, industrial drying systems, power generation turbines and flue gas stacks.

Physico-chemical fluid variables

Monitoring the physical and chemical variables of fluids, such as temperature, pressure and flow rate, as well as analytical parameters such as pH or turbidity, is essential in cooling circuits, boilers and water treatment plants, as any deviation in these variables leads to immediate energy costs, deterioration due to scaling or failures caused by corrosion.

Some of the main parameters for continuous monitoring of fluids and process water are:

• Conductivity and tracers: these are monitored in cooling tower water to automate the precise dosing of chemicals and reduce water wastage.
• Dissolved oxygen: this is measured in the liquids of biological reactors to control the blowers and optimise the electricity consumption of the aeration system.
• Redox potential: this is monitored in industrial water to evaluate disinfection processes, preventing the overdosing of oxidising biocides.
• Organic load and solids: these are analysed in final liquid effluents to detect pollution spikes in good time and avoid fines for exceeding discharge limits.

Energy consumption and material yield

Monitoring energy, heat or compressed air consumption for each production line reveals the true cost of manufacturing. By cross-referencing this data with the raw material conversion rate, plant managers can identify hidden bottlenecks, optimise resource usage and implement efficiency measures that have a direct impact on profit margins.

In sectors such as energy and cement, gas monitoring (O2, CO, NOx) allows the air-to-fuel ratio to be adjusted with surgical precision. Optimised combustion not only reduces emissions but also significantly lowers fuel consumption.

Benefits of continuous monitoring of production processes

The transition from manual or periodic checks to a system of uninterrupted monitoring radically transforms the profitability of any plant. Integrating this technology not only acts as a safeguard against penalties and delays, but also delivers strategic benefits across the entire value chain.

Cost reduction and OEE maximisation

Access to real-time metrics enables the identification of hidden inefficiencies and the elimination of bottlenecks, directly optimising operational performance. By maintaining a stable production rate with no downtime, raw material waste is minimised and fixed costs are spread across a higher production volume, reducing the unit cost, which tangibly increases Overall Equipment Effectiveness (OEE).

Predictive maintenance and extended service life

The installation of sensors and analysers that continuously monitor machinery performance acts as the facility’s nervous system. Early identification of anomalies such as overheating, imbalances or unusual vibrations drastically reduces unplanned plant stoppages. By avoiding mechanical overloads in the systems, premature wear is prevented and the service life of industrial assets is significantly extended.

Agile, data-driven decision-making

In today’s industrial environment, decisions are no longer based solely on historical analysis, but on the real-time status of the process. Centralising data enables plant managers to react proactively to operational variations, whilst also facilitating immediate remote technical support and reducing the margin for human error.

Industrial safety and strict regulatory compliance

Monitoring environmental parameters and process gases constitutes the first line of defence in protecting the health of plant personnel. Rapidly detecting hazardous levels of Volatile Organic Compounds (VOCs) or toxic leaks allows intervention before they exceed occupational exposure limits. At the same time, the continuous and automated recording of discharges and emissions ensures strict compliance with environmental regulations, generating robust traceability reports that prevent fines and operational shutdowns.

Energy efficiency and verifiable sustainability

Continuous monitoring is the technological cornerstone for achieving decarbonisation targets. By having accurate data on resource consumption (electricity, gas, water, etc.) for each production line, companies can make precise adjustments to boilers, compressors or cooling systems. Comprehensive control significantly reduces the environmental footprint and facilitates the attainment and renewal of the most demanding management and sustainability certifications.

Tables and appendices

List of industries and the main gas compounds or mixtures involved in production processes

Table of fluid and process water monitoring by industry type

References

• (1) https://www.i-scoop.eu/industry-4-0/energy-efficiency-industry-4-0/
• Wikipedia, Gases Industriales. https://es.wikipedia.org/wiki/Gas_industrial
• Ferreiro, S., Konde, E., Fernández, S., & Prado, A. (2016). Industry 4.0: predictive intelligent maintenance for production equipment. European Conference of the Prognostics and Health Management Society. (5-8, julio, 2016: Bilbao, España) https://papers.phmsociety.org/index.php/phme/article/view/1667
• Javied, T., Bakakeu, J., Gessinger, D., & Franke, J. (2018). Strategic energy management in industry 4.0 environment. 2018 Annual IEEE International Systems Conference (23-26, abril, 2018: Vancouver, Canadá).doi: http://doi.org/c2xk