Decomposition Front Research Articles

Characterization of the fire behaviour of an exterior insulation system at intermediate scale. Application to a high-pressure laminate (HPL) claddings

This paper presents the experimental results of intermediate-scale tests related to the fire behaviour of high-pressure laminate (HPL). The experiments correspond to a cladding submitted to an exterior fire, to study its thermal decomposition and burning behaviour when exposed to two heat fluxes: 30 kW m−2 and 60 kW m−2. Measurements of mass loss, mass loss rate (MLR), gaseous emissions, heat release rate (HRR), temperatures and position of the thermal decomposition front have been performed for two sample sizes of 50 × 50 cm2 and 100 × 100 cm2. Considering the mass loss, the MLR, the HRR and the temperatures, 3 stages have been identified during the fire development of the samples. The first one corresponds to the heating phase of the sample, the mass loss and gaseous emissions are almost null. However, the measurements of the thermal decomposition fronts highlight that this first stage of fire development can be divided into two phases: an initial phase where the front is spreading and a secondary phase where it remains constant. The second step corresponds to the inflammation of the sample. During this stage, temperatures reached 1000 °C in the air cavity and the heat fluxes on the upper part of the sample reached between 50 and 70 kW m−2. The last one corresponds to the extinction.

INJECTION OF SUPERHEATED WATER VAPOR INTO A POROUS RESERVOIR SATURATED IN THE INITIAL STATE WITH METHANE AND ITS HYDRATE

The work presents a mathematical model of the process of pumping superheated water vapor into a semi-infinite natural porous reservoir, which in its initial state is saturated with gas (methane) and its gas hydrate, in a flat-one-dimensional approximation. The most general case is considered, when four zones of different composition of the saturating phases and three moving boundary surfaces separating these zones appear in a natural reservoir: between the first and second zones, on which condensation of superheated water vapor occurs, between the second and third zones, where displacement takes place condensed methane water, as well as between the third and fourth zones, where the dissociation of the gas hydrate occurs. In the considered formulation of the problem, the first zone of the porous reservoir is saturated with superheated water vapor, the second zone is saturated with condensed water, the third zone is saturated with methane and still water (released during the dissociation of gas hydrate), and the fourth zone of the reservoir is saturated with methane and its gas hydrate. On the basis of a numerical solution, the hydrodynamic and temperature fields that arise in a porous reservoir are studied. It is shown that solutions with the indicated areas and boundaries exist only at relatively low values of injection pressure and reservoir permeability. It has been established that an increase in both the injection pressure and the reservoir permeability leads to a noticeable increase in only the coordinates of the boundary separating the second and third regions; in this case, the coordinate of the methane hydrate decomposition front is practically independent of the indicated parameters. An increase in the values of these parameters leads to the confluence of the boundaries of methane displacement and gas hydrate decomposition. The dependence of the limiting value of the injection pressure on the permeability at which these boundaries merge occurs is obtained.

Numerical Simulation of Natural-Gas-Hydrate Decomposition in Process of Heat-Injection Production

Heat-injection production is a common technique for gas-hydrate development, and the mechanism needs further in-depth study, particularly of the decomposition characteristics of natural-gas hydrate, which are important fundamental issues. The natural gas-hydrate-reservoir model is based on a mathematical description of reservoir properties that considers the effects of hydrate decomposition and reservoir stress conditions. The aim of our investigation was to analyze the production and decomposition characteristics of natural-gas hydrates based on the results of numerical simulations of heat-injection production. The effects of different heat-injection temperatures and heat-injection rates on production were compared, and the decomposition characteristics of hydrates were evaluated qualitatively and characterized quantitatively by temperature distribution, saturation distribution, and the decomposition front in the process of heat-injection production of natural-gas hydrate. The results showed that, with the increase in the heat-injection temperature, the decomposition front moved faster, the area share of decomposition zone increased, but the increase extent decreased. The high heat-injection rate had a more significant effect than the heat-injection temperature in promoting the decomposition of natural-gas hydrate.

ИНЖЕКЦИЯ ПЕРЕГРЕТОГО ВОДЯНОГО ПАРА В ПОРИСТЫЙ ПЛАСТ, НАСЫЩЕННЫЙ В ИСХОДНОМ СОСТОЯНИИ МЕТАНОМ И ЕГО ГИДРАТОМ

The paper presents a mathematical model of injection of superheated water vapor into a porous medium saturated in the initial state with gas (methane) and its hydrate. The mathematical model is constructed under the assumption of the formation in the formation of four regions containing steam, condensed water, gas hydrate and its decomposition products, as well as three movable boundaries separating these regions and moving deep into the formation. It is established that at low values of the initial temperature of the system, a regime corresponding to the confluence of the methane displacement boundary and the decomposition front of the gas hydrate is realized. It is shown that an increase in the temperature of the injected steam leads only to an increase in the vapor condensation coordinate, while an increase in the values of the initial hydrate saturation leads to a decrease in the decomposition coordinate.

Experimental study on the dual-gas co-production from hydrate deposit and its underlying gas reservoir

Short gas production periods and high production costs are two main challenges for the commercial exploitation of natural gas hydrates (NGHs). The NGHs deposit with enriched underlying free gas has drawn more attention, because the dual-gas co-production from hydrate zone and underlying free gas zone are expected to increase gas yields. We designed a method to prepare this kind of hydrate deposits that a hydrate layer over a free gas layer, and performed a series of dual-gas co-exploitation experiments to investigate its gas production characteristics via depressurization method. Results demonstrate that the temperature of hydrate layer and free gas layer exhibit different variation tendency during gas production process and lower production pressure attributes to higher gas production rate and gas recovery ratio. The wellbore set at underlying free gas layer is recommended because it can avoid lower initial local permeability around the well and prevent ice plug or hydrate reformation during gas production process. Meanwhile, it enhances the movement of hydrate decomposition front and further improves gas production efficiency. Compared with the NGHs reservoir with a single hydrate zone, the dual-gas co-production has higher gas production efficiency and lower temperature decrease to maintain the driving force of hydrate dissociation.

Research on Dynamic Movement of Temperature and Pressure During Hydrate Depressurization Mining

Abstract It is of great significance to study the dynamic movement of temperature and pressure during depressurization mining process of hydrate reservoir. This paper first obtains the formula for calculating the temperature and pressure of hydrate decomposition based on the law of conservation of mass, conservation of energy, and phase equilibrium, Hydrateressim (HRS) is used to carry out the numerical simulation of the front edge of the one-dimensional model. The results show the pressure and the hydrate saturation front are correlated with the temperature front edge and compared with the Computer Modelling Group Ltd. (CMG) simulation results. It is found that the pressure front edge is an area in the balance model and an interface in the dynamic model. Then the movement of the front edge of the three-dimensional model was simulated. By simulating the movement regulation of pressure, temperature, and hydrate saturation front of each layer at different times, the longitudinal decrease of each layer is compared and analyzed. The conclusion drawn is that the bottom-hole pressure of the production well is an important factor for production, and the endothermic reaction of hydrate will cause the dynamic movement of temperature to lag slightly behind the pressure and hydrate saturation. By determining the relationship between the pressure and the temperature front, the position of the front edge of the hydrate saturation can be inferred that it is the position of the decomposition front and it overcomes the limitation of the experimental method that the hydrate saturation cannot be measured.

Hydrate decomposition front within porous media under thermal stimulation and depressurization conditions: Macroscale to microscale

Natural gas hydrates are unstable and easily to be decomposed under warming or depressurizing condition. The complicated hydrate decomposition process is generally characterized by a moving decomposition front, yet the essence of decomposition front evolution is unclear and the evidence is lacking. In this study, X-ray computed tomography (X-CT) technology is used to reveal the dynamic process of macroscale and microscale evolution of hydrate decomposition front. The hydrate-bearing porous samples are synthesized in the high-pressure reactor and then decomposed by the thermal stimulation method and the depressurization method with X-CT scans in real time. Macroscale results show that isolated hydrates beyond the decomposition front remain undecomposed under both two decomposition conditions, indicating the oversimplification of the decomposition front as the boundary where gas hydrates are completely decomposed. Hence, the decomposition front is redefined as the boundary which divides the hydrate-bearing sediment into an interconnected zone and an isolated zone based on the interconnectivity of hydrate particles. Microscale hydrate decomposition behaviors show that, the heat transfer differences among pores, solid media, and gas hydrates under thermal stimulation condition result in the remnant of isolated hydrates beyond the outside-in moving decomposition front. The gas fugacity differences in gas phase, water layer, and dead-end pores under depressurization condition result in the remnant of isolated hydrates beyond the top-down moving decomposition front. More importantly, we found that the remnant grain-cementing hydrates could alter the thermal- hydro-mechanical-chemical (THMC) processes outside the decomposition front, and play important roles in formation stability and ecological environment by supporting the skeleton structure of hydrate-bearing sediments. These findings may provide implications and visual evidences for production efficiency improvement and environmental protection in future field tests of hydrate exploitation.

ВЛИЯНИЕ СТАРЕНИЯ НА ФАЗОВЫЙ СОСТАВ И МЕХАНИЧЕСКИЕ СВОЙСТВА ВАНАДИЙСОДЕРЖАЩЕЙ ВЫСОКОАЗОТИСТОЙ СТАЛИ

Complex solid solution hardening of austenitic chrome-manganese steels by nitrogen and carbon is one of the most effective ways of production of high-nitrogen austenitic steels (HNS) without using special casting methods. To enhance the solubility of interstitials in the metal liquid state and suppress undesired secondary phases of Cr2N and Cr23C6, the carbide-forming elements (for instance, vanadium) are added to the HNS composition. By now, there are no experimental works on the age-hardening of ultrahigh-interstitial vanadium steels (more than 1 % wt.). In the present work, the authors used the X-ray structure analysis method, electron microscopy, and the uniaxial static tensile tests to study the effect of temperature (600 °С and 700 °С) and duration (0.5 h, 5 h) of age-hardening on the structure and mechanical properties of ultrahigh-interstitial vanadium-containing Cr–Mn steel (Fe–22Cr–26Mn–1.3V–0.7C–1.2N, N+C=1.9 % wt.). The experiments demonstrated that due to the complex decomposition (by intermittent and continuous mechanisms) of austenite saturated by interstitials, the aging at 600 °С and 700 °С is accompanied by a solid-solution hardening of the austenitic phase by carbonitrides Cr2(N, С) and (V,Cr)(N,С). The study identified that the increased temperature and prolongation of age-hardening stimulate the movement of intermittent decomposition front from the boundaries to the center of austenitic grains. (V,Cr)(N,С) particles formed by the continuous decomposition in the austenitic grains hinder the propagation of the reaction front, meanwhile, the large spherical (V,Cr)(N,C) and Cr2(N,C) particles, not dissolved after quenching, have little effect on its movement. At the chosen age-hardening modes, the yield strength of steel increases, and the fracture elongation decreases.

Effects of underlying gas on formation and gas production of methane hydrate in muddy low-permeability cores

Hydrate reservoirs with underlying gas are generally accepted as the most promising energy resource for commercial exploitation. The underlying gas is an important part of the energy recovery of hydrate reservoirs. However, the gas production characteristics of hydrate reservoirs with underlying gas are rarely discussed. This paper aims to analyze the effects of underlying gas on the formation of hydrate and methane production behaviors by depressurization. In a core holder, marine soil obtained from the South China Sea was used to remold muddy low-permeability cores. The hydrate saturation of the muddy cores ranged from 25.2% to 48.3%. In this work, when the pressure difference between the underlying gas and the hydrate phase equilibrium is less than 2.6 MPa, the underlying gas pressure is the decisive factor for hydrate saturation. Besides, underlying gas can provide a relatively slow pressure drop rate for hydrate decomposition. The low permeability of the core caused by high hydrate saturation weakens the production of underlying gas and leads to the pressure gradient in the core. Hydrate decomposition front advances with the pressure gradient. Therefore, the production of underlying gas and hydrate decomposition are interdependent during depressurization. The experimental results demonstrated the existence of underlying gas could boost the exploitation potential and gas recoverability of hydrate reservoirs. These findings expand the understanding of joint exploitation characteristics and provide guidance in assessing the production potential for further researches and field exploitation of hydrate reservoirs with underlying gas.

The synthetic effect of traditional-thermodynamic-factors (temperature, salinity, pressure) and fluid flow on natural gas hydrate recovery behaviors

The commercial exploitation of natural gas hydrates (NGHs) has been a growing research focus due to its features of enormous reserves and clean fuel. To guarantee the safe and efficient production of NGHs, we have proposed a novel strategy of water flow erosion to promote methane hydrate (MH) decomposition based on the tremendous seawater resource and the fundamental process of water-gas flow during NGHs exploitation. In this study, the synthetic effects of traditional-thermodynamic-factors (temperature, salinity, pressure) and fluid flow on MH decomposition characteristics, which is known little about yet, are comprehensively analyzed via in-situ magnetic resonance imaging (MRI). The temporal-spatial behaviors of MH decomposition are visually investigated. The results indicate that the pressure, salinity, temperature and water flow synergistically increased MH decomposition efficiency. Additionally, the propagation of the decomposition front along the interface between MH and ambient phase shows that the water flow rate and heat transfer are two crucial factors for accelerating MH decomposition. The higher water flow rate also efficiently complements the insufficient decomposition driving force due to the heat loss during MH decomposition process. The highest average decomposition rate (1.1%/min) and the relatively less water injection volume (320 mL) can be archived in this study. Furthermore, the decomposition rate has a significant dependence on temperature under lower water flow rate.

Ultrasonic Temperature Compensating Method for Tracking Decomposition Front in Silica-Phenolic Thermal Protection Material

This paper presents an ultrasonic method for tracking the decomposition front in ablating silica-phenolic thermal protection system material. The method exploits diffuse ultrasonic backscatter from the material microstructure to account for the temperature-dependent change of the speed of sound. The method is demonstrated in a series of ablation tests performed at a heat flux of provided by an oxy-acetylene torch. Validation of the method is performed using machining, ultrasound, and micro–computed tomography scanning of the ablated samples. The measurement error in all tests does not exceed 1 mm. Analysis of the data suggests that, during the active ablation phase, temperature rise in the virgin material zone is low and the speed of sound correction is not required, whereas the main advantage of the method comes during the heat soak-back phase. Performed thermo-acoustic characterization of silica phenolic shows a linear dependence between the speed of sound and temperature up to 210°C. This finding opens a way to use the backscatter for estimation of temperature distribution in the virgin material. Finally, the study presents the measurement of acoustic attenuation to provide a reference for the application of the method to additional thermal protection materials, except silica phenolic.

Utilization of water-gas flow on natural gas hydrate recovery with different depressurization modes

Water-gas two-phase flow always exists in the natural gas hydrate production process. It has been confirmed that a suitable water-gas flow rate ratio can efficiently induce hydrate decomposition above hydrate phase equilibrium. Meanwhile, the water-gas flow may help to prevent the ice generation and hydrate reformation that need to be solved in the depressurization process. However, little is known about the synthetic effect mechanism of different depressurization modes and water-gas flow on hydrate decomposition. In this study, the piecewise depressurization, constant depressurization rate, constant gas recovery rate assisted with water-gas flow was used to decompose methane hydrate, respectively. The hydrate decomposition behaviors were investigated via magnetic resonance imaging. The results indicated that the hydrate decomposition characteristics showed spatial dependence, and the decomposition front was moved to the center from the edges along the interface of water and hydrate. Moreover, the higher water-gas flow rate ratio and faster depressurization rate led to a lower energy input (gas and water injection volume) and higher energy recovery rate (hydrate decomposition rate). Compared to sudden depressurization, the ice generation was efficiently avoided and the hydrate decomposition rate was remarkably improved for the all three decomposition modes. By comparison, the combination of piecewise depressurization incorporated with water-gas flow (mode I) was the best mode to recover gas from hydrate reservoirs in our experimental scale.

Analyzing the applicability of in situ heating methods in the gas production from natural gas hydrate-bearing sediment with field scale numerical study

For natural gas hydrate (NGH) exploitation, the in-situ electrical heating has been proved as a promising production method in laboratory experimental scale. But the results in this scale are difficult to reliably reflect field trials due to limitations in the size of the reactor. So, by TOUGH+HYDRATE software, this paper stimulates hydrate exploitation in field scale by in situ electrical heating. In addition, depressurization is applied as a comparison. Based on the analysis of several parameters like reservoir temperature and hydrate distribution, results show that although a larger heating power can result in a faster move of the decomposition front, the fast free gas production takes a large amount of sensible heat out of the reservoir. Also, the electrical heating effect is limited by the heat conductivity of formation in the field scale, so the heat promoting distance of the heating method is less than 10 m after five years production even with 1000 W/m of electrical heating power. A large amount of heat loss and the shortage of heating injection make the energy efficiency of it decreased significantly with the production time. So, large heating power cannot always remain fast gas and water production rates. Furthermore, the higher heating power does not mean a better exploitation effect. Thus, it is vital to choose a reasonable heating power in the field exploitation. Under the NGH reservoir and production parameters set in this paper, the most optimal electrical heating power should be 500 W/m with comprehensive consideration of gas production rate, NGH front promoting velocity and energy efficiency.

Numerical study of depressurization and hot water injection for gas hydrate production in China's first offshore test site

In 2017, China successfully conducted its first offshore gas hydrate production test by using vertical well in the Shenhu area, achieving a total gas production of 3.09 × 105 m3. However, there is still a long way to commercial production. In this study, to evaluate and improve the gas production potential of China's first hydrate production site, depressurization, and the combination of depressurization and hot water injection, were applied to natural gas hydrate (NGH) reservoir in China's first offshore hydrate production site to analyze 10 years' hydrate production features. The results indicated that the decomposition front of hydrate when using depressurization in two horizontal production wells had obvious non-uniform characteristics, and there were rapid decomposition regions and hydrate reformation regions. Among them, the hydrate reformation region may have adverse effects on hydrate decomposition. The combination of depressurization and hot water injection could improve total gas production and alleviate hydrate reformation. However, when the temperature of hot water injected increased from 35 °C to 80 °C, the energy efficiency decreased from 10.22 to 1.53, as a lot of energy was consumed to heat the sediments in the reservoir. When the hot water injection time was reduced from 3650 days to 1825 days, the energy efficiency could be effectively increased from 10.22 to 21.78 without significant reduction of the gas production. This work contributed to the present understanding of production behavior of depressurization and the combination of depressurization and hot water injection, and helped to evaluate the influence of hot water injected on gas production from NGH reservoir.

Decomposition prevention through thermal sensitivity of hydrate formations around wellbore

The traditional drilling engineering research on wellbore stability of hydrate formation neglects the interactions between heat transfer and mass transfer, a new multi-field coupling model is established to study the effects, and this model considers hydrate kinetic decomposition rate in different salinities, two-phase flows and heat transfer in pores. The calculation results show most of engineering parameters affects hydrate decomposition through high thermal sensitivity of hydrate formations: The direction and value of seepage will change the temperature field and the position of hydrate dissociation front. High bottomhole pressure will bring in the radial seepage, increasing formation temperature and exacerbating hydrate decomposition. The latent heat of hydrate dissociation reduces temperature growth in the entire formation, inhibits the decomposition front advancement and decreases the decomposition rate. Reducing the bottomhole temperature can get an incremental margin for wellbore stability. High salinity in drilling fluid will provide negative impact under high bottomhole pressure and high permeability. These results show the protection of hydrate formations should avoid increasing the density of drilling fluid and focus on cooling drilling fluid and reducing drilling time.

Macroscopic defects upon decomposition of CO2 clathrate hydrate crystals.

Micrometer- and submicrometer-sized pores and macroscopic defects like cracks and tubular channels can be found in a variety of clathrate hydrates (hydrates for short) during formation and decomposition. Their origin, their evolution in time, and their effect on hydrate decomposition kinetics are unclear. We used time-lapse micro computed tomography (μCT) in combination with temperature control and pressure monitoring to study the formation and evolution of pores and macroscopic defects in decomposing CO2 hydrates at subzero (Celsius) temperature. Our results suggest that the decomposition of hydrates is always accompanied by the formation of pores and an increase of the apparent hydrate volume by more than 3%. Hydrate decomposition often starts with the formation of cracks inside the hydrate and not necessarily at the free surface of the hydrate, which frequently remains intact for a long period and seems to be self-preserved in some regions. Decomposition spreads out from these cracks in a uniform fashion yielding a variety of macroscopic features. In some cases, the propagating decomposition front seems to get blocked by planar barriers inside the hydrate yielding regions with high resistance against decomposition. This, together with a generally heterogeneous distribution of decomposition resistant regions, challenges the shrinking core model of hydrate decomposition as well as the popular ice-rind theory used to explain the effect of self-preservation.

Analysis of depressurization mode on gas recovery from methane hydrate deposits and the concomitant ice generation

Natural gas hydrates have garnered worldwide attention as an important potential non-conventional fossil fuel resource. When extracting natural gas from gas hydrate deposits via depressurization, problematic ice generation and hydrate reformation can occur under conditions of fast depressurizing and low production pressures, due to insufficient heat transfer in the surrounding sediments. In this work we conduct in situ magnetic resonance imaging (MRI) visualization and analysis of hydrate decomposition behavior for different depressurization modes; we visually determine the volumetric and spatial characteristics of the hydrate decomposition during depressurization induced gas production operation. Our results indicate that fast depressurization rate can result in a fast hydrate decomposition rate, therefore, a rapid gas production rate. In addition, the radial extension behavior of the decomposition front confirms that ambient heat transfer is a critical factor driving hydrate decomposition into free gas and liquid water. Obvious hydrate reformation and ice generation phenomenon, seen in some of the sudden depressurization experiments, can be effectively avoided using piecewise and continuous depressurization methods. The findings of this study clearly demonstrate how production pressures affect the gas production behavior from hydrate deposits and provide further insight for establishing optimal production techniques for utilizing hydrate resources in the field.

Modelling Behaviour of a Carbon Epoxy Composite Exposed to Fire: Part II-Comparison with Experimental Results.

Based on a phenomenological methodology, a three dimensional (3D) thermochemical model was developed to predict the temperature profile, the mass loss and the decomposition front of a carbon-reinforced epoxy composite laminate (T700/M21 composite) exposed to fire conditions. This 3D model takes into account the energy accumulation by the solid material, the anisotropic heat conduction, the thermal decomposition of the material, the gas mass flow into the composite, and the internal pressure. Thermophysical properties defined as temperature dependant properties were characterised using existing as well as innovative methodologies in order to use them as inputs into our physical model. The 3D thermochemical model accurately predicts the measured mass loss and observed decomposition front when the carbon fibre/epoxy composite is directly impacted by a propane flame. In short, the model shows its capability to predict the fire behaviour of a carbon fibre reinforced composite for fire safety engineering.

Heat and mass transfer analysis of depressurization-induced hydrate decomposition with different temperatures of over- and underburden

Natural Gas Hydrate (NGH) reserves are large and regarded as an important alternative future energy source. Safely and efficiently exploiting natural gas hydrates has recently become a hot issue around the world. The decomposition of natural gas hydrate requires a great deal of absorbed heat. The decomposition process is a complicated heat and mass transfer process with phase changes, such that heat and mass transfer will have a great impact on the decomposition results. Focusing on the heat transfer effect, a two dimensional mathematical model of natural gas hydrate decomposition was established. Using a numerical simulation method, the thermal conductivities of different porous mediums were selected and the bottom hole pressure (BHP) was changed under different overburden and underburden temperatures to simulate the depressurization exploitation of natural gas hydrates. The reservoir temperature distribution, hydrate decomposition front, gas production rate, and cumulative gas production under different cases were obtained. The results show that the incoming heat directly influenced the reservoir temperature distribution, hydrate decomposition rate, and gas production and the temperature at any point on the decomposition front is constant under certain BHP. When there was no external heat introduced into the hydrate-bearing layers, the impact of thermal conductivity on decomposition was greater, but decreased with increasing temperature of overburden and underburden. When no external heat was introduced into the hydrate-bearing layers, the BHP became the main controlling factor of the cumulative gas production, and the effect of the BHP on the cumulative gas production was gradually weakened with increasing temperatures of the overburden and underburden.

Engineering model for intumescent coating behavior in a pilot‐scale gas‐fired furnace

In the event of a fire, intumescent fire protective coatings expand and form a thermally insulating char that protects the underlying substrate from heat and subsequent structural failure. The intumescence includes several rate phenomena, which have been investigated and quantified in the literature for several decades. However, various challenges still exist. The most important one concerns mathematical model validation under realistic exposure conditions and/or time scales. Another is the simplification of advanced models to overcome the often‐seen lack of a complete set of input and adjustable model parameters for a given coating, thereby providing models for industrial applications. In this work, these two challenges are addressed. Three experimental series, with an intumescent coating inside a 0.65 m3 gas‐fired furnace, heating up according to so‐called cellulosic fire conditions, were conducted and a very good repeatability was evident. The experiments were run for almost 3 h, reaching a final gas temperature of about 1100°C. Measurements include transient temperature developments inside the expanding char, at the steel substrate, and in the mineral wool insulation placed behind the substrate. A mathematical model, describing the intumescent coating behavior and temperatures in the furnace using a single overall reaction was developed and validated against experimental data. By including a decomposition front movement through the char, a good qualitative agreement was obtained. After further validation against experiments with other coating formulations, it has potential to become a practical engineering tool. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3947–3962, 2016