The development and deployment of a real-time, in situ, non-invasive sensor to monitor the concentration of H 2 O during in situ combustion (ISC) experiments with a heavy-crude oil is described. A real-time sensor to monitor the gas-phase products from ISC can support the study of the kinetics of the complex chemical reactive system in ISC. The mole fraction of H 2 O was measured using tunable diode laser (TDL) absorption spectroscopy coupled with 1 f -normalized wavelength modulation spectroscopy (WMS) and 2 f detection. The WMS 2 f / 1 f strategy was used to enhance sensitivity with effective noise rejection, particularly suitable when characterizing the water vapor evolved from oil–water emulsions. H 2 O was measured at 3934.10 c m − 1 from the fundamental band v 3 . That transition was selected using the HITRAN database to increase the line strength and minimize interference from neighbor compounds. Measurements of H 2 O concentration were conducted at ambient temperature and pressure using a reference cell ( H 2 O = 2 % at 98.6 kPa) to validate the sensor architecture under controlled laboratory environments. The TDL sensor was also successfully validated during real ISC experiments involving heavy-crude oil. Validation and combustion experiments showed the potential of the TDL-based sensor for non-invasive, real-time, in situ measurements of gas-phase species in conditions similar to those of laboratory-scale experimental ISC tests.

A simulation tool was designed for analyzing various experimental setups that include the ability to model detailed chemical reaction schemes for in-situ combustion (ISC) analysis.,. The simulation tool was illustrated with a theoretical example to the extent of CO oxidation in a gaseous phase takes place during ISC. The models in the simulation tool are based on fundamental conservation laws, physical correlations for porous media properties, and property databases available in literature. Emphasis is made on the analysis of chemical reactions in the gas phase, a characteristic that may be useful when temperatures are above 700°C and oxygen, unburned hydrocarbons, and CO coexist. The three modules of the simulation tool: (i) Kinetic cell, (ii) One-dimensional reactor, and (iii) Combustion tube, can be used to represent in detail the processes taking place in the typical laboratory-scale equipment used to characterize ISC. Tools for the analysis of transport phenomena and multiphase reactions, present in all three models, can support the process of finding chemical kinetic parameters for an easier calculation of device-independent kinetic constants. Four applications have the simulator scope: (i) Analysis of reactions in the gas phase, (ii) Axial gradients in a kinetic cell, (iii) Pressure build-up in a combustion tube, and (iv) Ignition in a combustion tube. These examples highlight the importance that homogeneous reactions may have in these systems and the existence, under certain conditions, of concentration gradients that are normally neglected, and can affect the interpretation of ISC experiments.

Incidents, such as the fire that occurred between December 21st and 23rd 2022 at the fuel tank storage facility in Barranquilla, remind Colombian industries of the risk of fires. Chemical engineers are responsible for designs and technologies that prevent fires and explosions. Yet, fire and explosion safety is not a subject that is explicitly addressed in the Chemical Engineering curriculum. This study describes an educational module that fosters in Chemical Engineering undergraduate students competencies relevant in fire safety. Through an analysis of a pool fire that occurred in a chemical plant in Colombia, an educational module on fire and explosion safety was developed. The module describes basic concepts related to fire safety such as pool fires, dikes, vapor pressure, and flammability limits, and highlights the differences between prescriptive vs. performance-based design. It also illustrates the use of Physical Modeling Tools (PMTs) as an example of emerging technologies in fire safety. The module was presented to first-semester students in the Introduction to Chemical Engineering class and advanced students in the Process Engineering class at Facultad de Minas, Universidad Nacional de Colombia Sede Medellín. The impact of the module was evaluated by surveying the students on the perceived importance of the competencies for fire and explosion safety, before and after taking the module, and comparing the results with the order of importance of the competencies as defined by a group of experts in fire and explosion safety. The module was deemed an effective way to increase the awareness of Chemical Engineering students on fire and explosion safety.

This study provides evidence that a helium-neon (He-Ne) laser operating in the Mid-infrared (MIR) at a wavelength of 3.39 μm can detect variations in 1-hexene concentration in the presence of a solid catalyst. The in-situ and online characterization of the concentration of 1-hexene, as an example of a hydrocarbon, is relevant to enhance the current understanding of the interaction between hydrodynamics and chemistry in different heterogeneous catalytic processes. We designed and built a laboratory-scale downer unit that enabled us to analyze heterogeneous catalytic reactions and provided optical access. The lab-scale reactor was 180-cm long, had an internal diameter of 1.3 cm, and was made of fused quartz to allow the passage of the laser beam. 1-hexene was carefully measured, vaporized, and fed into the reactor through two inlets located at an angle of 45 degrees from the vertical descendent flow and 70 cm below the input of a solid catalyst and a purge flow entraining N2. A system of five heaters, which can be moved in the vertical direction to allow the passage of the laser beam, guaranteed temperatures up to 823 K. Computational Fluid Dynamics (CFD) simulations of the hydrodynamics of the system indicated that a uniform temperature profile in the reaction section was reached after the catalyst and the feed mixed. The estimated catalyst to oil ratio and time on stream in the experiments were, respectively, 0.4 to 1.3 and 2 s. After a correction for laser power drift, the experimental results showed a linear response of the fractional transmission to the 1-hexene concentration that was independent of temperature in the 373 K–673 K range. Even in the presence of a catalyst, the absorption of 1-hexene at the MIR frequency of the laser was high enough to enable the detection of 1-hexene since the fractional absorption of the absorbing path length in these experiments was close to zero (0.013 m) and the 1-hexene concentrations were higher than 1.254 × 10^-5 mol/cm³. This result demonstrated the ability of the laser system to measure the concentration of 1-hexene in the presence of a catalyst and indicates that it can be used to better decouple hydrodynamics from kinetics in heterogeneous catalytic processes.

Fire and explosion safety personnel are exposed to physical modelling tools in performance design, incident investigation and education. It is, therefore, essential to know which tools are available and in which cases they can be used. Objective: to describe the different features of physical modelling tools that are available to personnel involved in fire and explosion safety, and to simulate the scenarios. Materials and methods: To perform simulations to evaluate some of these tools to determine the characteristics. These are illustrated by examples for different scenarios: 1) Compartment fires: Consolidated Model of Fire and Smoke Transport, Fire Dynamic Simulator, FireFoam. 2) Ventilation after a fire in underground spaces: VentFIRE and MFIRE. 3) Vegetation cover: Fire Dynamic Simulator and FlamMap. 4) Fire by ponding: Fire Dynamic Simulator. 5) Explosions: Ansys Fluent, Flame Acceleration Simulator, Cantera, Shock and Detonation Toolbox and XiFoam. Results: In the case of fires, it was identified that the Fire Dynamic Simulator is the most versatile physical modeling tool since it can be used in compartment fires, in the urban/vegetation cover interface and by ponding. For the analysis of the instant before an explosion, computational fluid dynamics simulations are recommended. For the study of the effect of the explosion, it is suggested to use Flame Acceleration Simulator or XiFoam. Conclusions: The need to train professionals in the management of these physical modeling tools in such a way that their responsible use in fire and explosion safety is guaranteed was identified, and the importance of conducting research that increases the capabilities of these tools through the application of artificial intelligence was recognized.