Drop Tube Reactor Research Articles

Research on Activation Mechanisms In Situ during Rapid Desorption of Mercury-Absorbing Activated Coke by the Heating Method.

The adsorption of active coke is a good method to control mercury in coal-fired power plants, but spent powdered activated coke (SPAC) will cause secondary pollution and waste of resources if it is not properly treated. The purpose of this study was to explore the desorption performance of SPAC when heated in a drop-tube reactor under different atmospheres. The carbon consumption was 0.13%, 0.24%, 0.17%, 0.16%, and 0.14%, under desorption conditions in N2, O2, H2O, CO2, and SFG (N2 + 12% CO2 + 6% H2O + 6% O2) atmospheres, respectively. The readsorption performances of PAC-N2, PAC-CO2, PAC-H2O, PAC-O2, and PAC-SFG were 40%, 72%, 77%, 58%, and 86%, respectively. In particular, compared with the original PAC, the physicochemical properties of PAC-SFG (optimum conditions) changed greatly; the surface area of PAC-SFG and the pore volume increased by 14.1% and 11.6%, respectively, and the average pore diameter decreased by 0.203 nm. Furthermore, the total acid content of PAC-SFG was 0.505, which was greater than those of the other samples. Additionally, the desorption and activation mechanisms in situ were determined under the optimum reaction conditions. The results showed that the activator gas reacted with C to form new functional groups, Lewis acid sites, and developed pore structures, which could increase Hg0 adsorption efficiency from 66% to 86% after the adsorption/desorption cycles. This study provides a novel idea for the reuse of SPAC, and this research is expected to provide valuable guidance for Hg0 removal and SPAC activated in situ during rapid desorption processes in future large-scale engineering applications.

Deactivation of iron particles during combustion and reduction

Iron is a promising carbon-free renewable energy carrier to replace fossil fuels. However, during a redox cycle, iron may experience deactivation due to structural changes, which can shorten the cycle lifetime. In this work, deactivation of iron particles in terms of changes in reactivity and morphology during the oxidation and reduction process was investigated, under both fixed-bed and suspension conditions. Simple thermal treatment in an inert atmosphere at 1200 °C had no influence on the reactivity of particles towards oxidation, even at long exposure resulting in mild agglomeration. In fixed-bed oxidation at 600 to 1100 °C, solid sintering was found to be rapid and severe at higher temperatures. However, the sintering showed no influence on the reactivity of particles towards H2 under slow-heating conditions in a TGA. In pulverized-fuel combustion in a drop tube reactor, the intensive combustion and heat release led to melting of particles and morphology change from irregular to spherical. As the reactor temperature was increased from 800 to 1200 °C, the particle reactivity in terms of reduction degree (fractional conversion from Fe2O3 to Fe) slightly decreased from 78 % to 72 %, possibly related to a minor loss of surface area. TGA experiments involving successive redox cycles showed a steady decline in reduction reactivity (750 °C, 2.5 % H2), slightly enhanced by agglomeration, while the oxidation degree (950 °C or 1200 °C, 21 % O2) remained constant. The present work indicates that both deactivation and loss of iron due to evaporation may serve to limit the energy release in iron combustion over extended cycles.

Pyrolysis of high-density polyethylene: Degradation behaviors, kinetics, and product characteristics

Pyrolysis is a promising technology for converting plastic waste into valuable raw materials while offering a potential solution to the global plastic pollution crisis. In this study, the thermal pyrolysis of high-density polyethylene (HDPE) is investigated in a drop tube reactor under nearly isothermal conditions. The impact of reaction temperature and gas/volatile residence time on carbon conversion and product distribution is examined across a range of 500–900 °C and 3.6–32.2 s, respectively. Non-condensable gas products detected by online mass spectrometry are H2, CH4, C2H4, C2H6, C3H6, and C3H8. At elevated temperatures and prolonged residence time, H2 yield reaches as high as 8.6 wt% of the initial HDPE mass due to intensified cracking reactions of C2–C3 hydrocarbons and long-chain aliphatic compounds. Consequently, pyrolysis tars consist mainly of polycyclic aromatic hydrocarbons (PAHs) with 5–7 rings, accompanied by visible coke deposition within the reactor. HDPE decomposition to volatiles is an endothermic process and it is complete at a temperature between 492 °C and 525 °C, depending on the heating rate employed, from non-isothermal thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) measurements. The thermal degradation of HDPE pellets follows the two-dimensional nucleation growth model for conversion levels up to 0.8 with an apparent activation energy of 259–270 kJ/mol and a pre-exponential factor of 4.83 × 1017–1.37 × 1019 min−1, determined from various isoconversional methods such as Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Starink, along with Criado's master plots. These findings provide valuable insights into optimizing process parameters and refining reactor design for pyrolysis, which can be integrated with gasification and reforming processes to enhance hydrogen production on a larger scale.

Single particle conversion of woody biomass using fully-resolved and Euler–Lagrange coarse-graining approaches

The conversion of woody biomass is studied by means of a layer-based model for thermally-thick biomass particles (Thunman et al. 2002, Ström et al. 2013). The model implementation is successfully validated against experiments that study particle conversion in a drop tube reactor. After this validation step, this work focuses on the well-known problem of grid dependence of two-phase numerical simulations using the standard Euler–Lagrange (EL) framework. This issue is addressed and quantified by comparing EL data that models the particle boundary layers to corresponding simulations which fully resolve these boundary layers (fully-resolved, FR, simulations). A comparison methodology for the conceptually different FR and EL approaches by extracting the heat transfer coefficient from the detailed FR simulations is proposed and confirms that the EL results are strongly grid-dependent. This issue is overcome by applying a set of coarse-graining methods for the EL framework. Two coarse-graining methods are evaluated, a previously suggested diffusion-based method (DBM) and a new approach based on moving averages referred to as MAM. It is shown that both DBM and MAM can successfully recover the detailed FR data for pure particle heating for a case where the grid size is half the particle diameter, i.e. when the standard EL method fails. Both coarse-graining methods also give improved results for an EL simulation that considers the more complex combined physics of particle heating, drying and devolatilisation, given that the CG model parameters that scale the corresponding CG interaction volumes are sufficiently large. Based on the available FR data, recommended model parameter ranges for DBM and MAM are provided as a function of normalised boundary layer thickness. The novel MAM approach is shown to be significantly more efficient than the DBM and therefore suitable for future EL simulations with multiple particles.

Fast pyrolysis of agricultural biomass in drop tube reactor for bio-oil production: Numerical calculations

Fast biomass pyrolysis is an effective method for bio-oil production and can be performed in fluidised beds, augers, and drop-tube reactors. In this study, the fast pyrolysis of agricultural biomass (oat and corn straw) in a drop-tube reactor was investigated by applying multiparameter analysis involving numerical calculations. The main motivation for this analysis was to determine the operating parameters for fast pyrolysis under which the highest bio-oil production was achieved. In this study, the following operating parameters were involved: pyrolysis temperature (500 – 700 °C), volume flow rate of the carrier gas (3 – 5 l/min), mass flow rate of the feedstock (10 – 30 g/h), and diameter of the particle (250 – 750 µm). The analysis was performed using numerical methods with the Euler-Lagrange multiphase theory in a 2D axisymmetric model. According to the numerical results, selection of a particle size of 500 µm, pyrolysis temperature of 500 °C, and nitrogen flow rate of 3 l/min allows obtaining 51.16% and 52.09% of bio-oil for oat straw and corn straw pyrolysis, respectively. The biomass mass load did not influence the final product yield. The numerical results were successfully confirmed by experimental investigations where experiments supplied 53.2% and 51.3% of bio-oil to oat straw and corn straw, respectively.

Xylan fast pyrolysis: An experimental and modelling study of particle changes and volatiles release

Biomass char particles produced by pyrolysis may have different morphologies, which has important implications on burning mode, conversion rate and boiler efficiency. These features are difficult to address due to the complexity of biomass structure and pyrolysis reaction models.The present work reports preliminary results on the morphological changes and volatile release that solid particles of Xylan experience upon fast heating in a Drop Tube Reactor (DTR) and in a Heated Strip Reactor (HSR) in a range of temperature between 1100 and 1573 K under inert atmosphere with heating rate in the order of 103 K/s. Two different Xylan samples were chosen as representative of Hemicellulose in angiosperm biomass: xylooligosaccharide extracted from Beechwood (hardwood biomass) and from Corn Cob (herbaceous biomass).During the heatup phase, Xylan particles do not retain the original shape and morphology, neither in DTR nor in HSR experiments. In the early pyrolysis stage, Xylan particles melt and form viscous droplets. As devolatilization proceeds these droplets in the DTR evolve into highly viscous sponge-like particles with spherical shape, which swell and eventually shrink, ultimately producing highly porous spherical char particles.The experimental results are compared with the predictions obtained by the Bio-CPD Xylan pyrolysis model. The model is fairly able to calculate the pyrolysis yields in the DTR, but predicts unexpectedly low extent of metaplast formation. To explain the remarkable melting phenomena and morphological changes observed in the experiments, tuning of some CPD parameters and inclusion of mass transfer and pressure build-up within the particles might be necessary in future work.

Performance assessment of drop tube reactor for biomass fast pyrolysis using process simulator

AbstractBiomass pyrolysis process from a drop tube reactor was modelled in a plug flow reactor using Aspen Plus process simulation software. A kinetic mechanism for pyrolysis was developed considering the recent improvements and updated kinetic schemes to account for different content of cellulose, hemicellulose, and lignin. In this regard, oak, beechwood, rice straw, and cassava stalk biomasses were analyzed. The main phenomena governing the pyrolysis process are identified in terms of the characteristic times. Pyrolysis process was found to be reaction rate controlled. Effects of pyrolysis temperature on bio‐oil, gases, and char yields were evaluated. At optimum pyrolysis conditions (i.e., 500°C), a bio‐oil yield of 67.3, 64, 43, and 52 wt.% were obtained from oak, beechwood, rice straw, and cassava stalk, respectively. Oak and beechwood were found to give high yields of bio‐oil, while rice straw produced high gas and char yields compared to other biomasses. Although temperature is the main factor that plays a key role in the distribution of pyrolysis products, the composition of cellulose, hemicellulose, and lignin in the feedstock also determines the yield behaviour and composition of products. With the rise in pyrolysis temperature, further decomposition of intermediate components was initiated favouring the formation of lighter fractions. Comparably, species belonging to the aldehyde chemical family had the highest share of bio‐oil components in all the investigated feedstocks. Overall, the present study shows a good agreement with the experimental study reported in the literature, confirming its validity as a predictive tool for the biomass pyrolysis process.

Numerical investigations of biomass pyrolysis with partial oxidation in a drop tube reactor

This study relates to 2D numerical calculations of fast pyrolysis with partial oxidation of pine and pine bark in a drop-tube reactor at 550 °C. Numerical studies were supported by experiments using thermogravimetric analysis of pine, pine bark, and pure lignin. The study involved 3 atm of pyrolysis: pure nitrogen, 95% nitrogen/5% oxygen, and 90% nitrogen/10% oxygen v/v. Numerical calculations were performed using Euler–Lagrange multiphase theory. According to the results, it was possible to linearly reduce the amount of char from 49% to 34% for pine and from 57% to 36% for pine bark, as the oxygen content in the carrier gas increased from 0 to 10% v/v. Furthermore, the addition of oxygen decreased the required energy for pyrolysis from 1.55 to 1.1 MJ/kg for pine and from 1.6 to 1.1 MJ/kg for pine bark at the maximum considered oxygen content. Simultaneously, owing to the increasing oxygen content in the carrier gas, gaseous products were promoted, and the mass ratio of CO to CO2 was almost the same for all cases and was approximately 0.6.

Fast pyrolysis multiphase CFD-kinetics model in a drop tube reactor

Experimental investigation of biomass pyrolysis kinetics is challenging due to simultaneous complex chemical reactions, interphase heat and mass transfer. A CFD model and simulation overcome the challenges faced in experimental work and provides a detailed characterization of pyrolysis kinetics. In this work, a granular multiphase flow model with 17 heterogeneous reactions, 53 interphase mass transfer, and 35 pyrolysis species and Nitrogen (36 species) transport models was implemented to investigate the pyrolysis kinetics using a continuous flow drop tube reactor (DTR). The model predicted that 45 wt% biofuel, 25 wt. % permanent gases, 10 wt% water and 20 wt% biochar is produced from a biomass feedstock at a reactor wall temperature of 773 K. The majority of biofuel (35 wt%) is produced from cellulose. While hemicellulose and lignin mainly produce permanent gases (16 wt%) and biochar (8 wt%), respectively. Product characterization and visualization of the pyrolysis process in a virtual environment mimicking the actual reactor in real-time sheds light on the pyrolysis reaction processes lacking in the literature.

Mineral effects on chemical and physical transformations of fast pyrolysis products of cellulose-based model fuels in N2 and CO2

This paper investigates the changes in reactivity and physicochemical characteristics of char and tar produced from severe heat treatment in either inert or CO2-rich atmospheres of a synthetic fuel doped with Fe&Mg and K&Mg sulfates. The mineral-free model fuel was obtained by hydrothermal carbonization (HTC) of cellulose. The comparison of Py-GC/MS-GC/TCD, heated strip reactor (HSR), and drop tube reactor (DTR) results highlighted that mineral doping, heating rate, temperature, residence time and atmosphere all interacted and influenced the pyrolysis products. Fe&Mg increased the light permanent gases during flash pyrolysis. The minerals catalytically affected the decomposition of the levoglucosan fraction in the tars. In N2, the addition of K&Mg influenced the oxy-aliphatic tars, while Fe&Mg had a stronger impact on oxy-aromatic compounds. Depending on the pyrolysis temperature and residence time (and reactor type), CO2 inhibited (700 °C in the HSR) or enhanced (1027 °C in the DTR) the formation of polycyclic aromatic hydrocarbon (PAHs) in the tars. Chars doped with Fe&Mg always exhibited higher reactivity than the chars doped with K&Mg. While the presence of CO2 during pyrolysis favored the aromatization of the chars especially in combination with doped minerals, alkali mineral interaction with CO2 decisively altered char reactivity.

Experimental and numerical investigations on the heat production and thermal storage characteristics of rapid preparation amorphous powder activated coke

• Preparation of rapid preparation amorphous powder activated coke was showed. • The oxidation characteristics of RAC were studied through experimental method. • The Arrhenius equation was used to analyze the oxidation reaction rate of RAC. • The thermal storage characteristics of RAC were studied with CFD simulation. • The temperature fields and concentration fields of coke bin were analyzed. The heat production and thermal storage characteristics of rapid-preparation amorphous powder activated coke (RAC) were investigated. RAC was prepared by using a drop-tube reactor system. The natural oxidation characteristics of RAC were studied through combined TG–FTIR analysis and temperature-programmed experiment. Experimental results showed that CO and CO 2 were the main oxidation products of RAC in air, and that the oxidation reaction was in accordance with the Arrhenius equation and law of mass action. Thermal storage characteristics were studied through computational fluid dynamics simulation. The maximum excess temperature θ max increases linearly with the increase of the initial temperature. The concentration fields of the products show that CO 2 is mainly concentrated in the upper part of the coke bin, and the CO generated by CO 2 at high temperature is mainly concentrated in the central part of the coke bin.

Systematic investigation of SO2 adsorption and desorption by porous powdered activated coke: Interaction between adsorption temperature and desorption energy consumption

Porous carbon materials have been widely used for the removal of SO 2 from flue gas. The main objective of this work is to clarify the effects of adsorption temperature on SO 2 adsorption and desorption energy consumption. Coal-based porous powdered activated coke (PPAC) prepared in the drop-tube reactor was used in this study. The N 2 adsorption measurements and Fourier transform infrared spectrometer analysis show that PPAC exhibits a developed pore structure and rich functional groups. The experimental results show that with a decrease in adsorption temperature in the range of 50–150 °C, the adsorption capacity of SO 2 increases linearly; meanwhile, the adsorption capacity of H 2 O increases, resulting in the increase in desorption energy consumption per unit mass of adsorbent. The processes of SO 2 and H 2 O desorption were determined by the temperature-programmed desorption test, and the desorption energies for each species were calculated. Considering the energy consumption per unit of desorption and the total amount of adsorbent, the optimal adsorption temperature yielding the minimum total energy consumption of regeneration is calculated. This study systematically demonstrates the effect of adsorption temperature on the adsorption–desorption process, providing a basis for energy saving and emission reduction in desulfurization system design.

Pengaruh Kondisi Temperatur Pirolisis Tandan Kosong Kelapa Sawit Terhadap Komposisi Produk Tar

Oil palm empty fruit bunch (EFB) is one of the biomass wastes that have a great potential of a bioenergy resource due to its natural properties, such as high calorific value. The conversion of EFB biomass into valuable biofuels can achieved through biochemical and thermochemical processes. Tar (bio-oil), the liquid product from the pyrolysis is one of the most attractive biofuels. The study aims to determine the effect of temperature process of pyrolysis EFB on its tar production under droptube reactor. The results showed that maximum tar yield was 43,80% obtained at 500 °C. The EFB tar produced at 500 °C was also determined to have a higher of phenol compound at 51,9%. The high phenolic content indicates its potential to be used for the production of renewable phenolic resins. Hence, the present work of pyrolysis of EFB presents itself as a promising method to produce phenol rich tar (bio-oil) from biomass waste.

Bio-fuel production from catalytic fast pyrolysis of Jatropha wastes using pyroprobe GC/MS and drop tube pyrolyzer

The effects of temperature and catalytic activity on the decomposition of Jatropha waste to bio-oil under rapid pyrolysis were investigated in this study. The pyrolytic conversion of Jatropha wastes was performed at the temperature range of 400–700 °C. The reactions were conducted and compared between two operations, an analytical pyroprobe GC/MS (µg-scale reactor) and a larger scale, drop tube pyrolyzer. Added catalysts were modified metal (Ce, Co, Ni, and Pd) over activated carbon (Ac) support. In non-catalytic trials, Jatropha wastes pyrolyzed at 600 °C yielded vapor products of mainly oxygenated compounds of acid-ester, aldehyde, and ketone. Addition of Ni/Ac and Pd/Ac catalysts resulted in significantly higher aromatic and total hydrocarbon (aliphatic and cyclic) fractions. The findings suggested that these catalysts are suitable for further investigation with a scaled-up fast pyrolysis sequential process, a drop tube reactor, to convert Jatropha waste into bio‐oil as well as various gaseous and solid byproducts depending on the operating conditions. In this case, the maximum liquid products (bio-oil) yield of 40 wt% was obtained at the reaction temperature of 600 °C and particle size of 0.125–0.425 mm with the presence of Ac. Reaction at 600 °C with Pd/Ac catalyst yielded bio-oil with the highest HHV of 29.20 MJ/kg with a pH of 6.78. Analysis of bio-oil by GC/MS revealed the main favorable products as phenols, aromatics, and hydrocarbons which increased almost two folds from base case with Ni/Ac and Pd/Ac addition. Since low oxygenated compounds, high aromatics, and hydrocarbon compounds of bio-oil are desirable, the results indicate that the bio-oil at the optimized condition can be readily applied as biofuel. Moreover, the obtained biochar as a co-product from fast pyrolysis of Jatropha wastes can be used as an alternative solid fuel.

Carbonation Kinetics of Ca(OH)2 Under Conditions of Entrained Reactors to Capture CO2.

The use of Ca(OH)2 as a CO2 sorbent instead of CaO in calcium looping systems has the advantage of a much faster reaction rate of carbonation and a larger conversion degree to CaCO3. This work investigates the carbonation kinetics of fine Ca(OH)2 particles (<10 μm) in a range of reaction conditions (i.e., 350–650 °C and CO2 concentrations up to 25%v) that could be of interest for applications where a short contact time is expected between the solids and the gases (i.e., entrained bed carbonator reactors). For this purpose, experiments in a drop tube reactor with short reaction times (i.e., below 6 s) have been carried out. High carbonation conversions up to 0.7 have been measured under these conditions, supporting the viability of using entrained carbonator reactors. The experimental results have been fitted to a shirking core model, and the corresponding kinetic parameters for the carbonation reaction have been determined.

Investigation of the combination of fractional condensation and water extraction for improving the storage stability of pyrolysis bio-oil

To improve the storage stability of bio-oils obtained from beech wood intermediate pyrolysis in a drop tube reactor, the combination of three-stage condensation with an additional water extraction system was accomplished to produce separated and purified bio-oil products. The physicochemical properties and composition variation of bio-oil during aging at different storage temperatures (4 °C, room temperature-18 °C, and 50 °C) and different storage times (1, 2, 3, and 4 weeks) were studied and compared to that of fresh bio-oil. The water content of each bio-oil product increased compared to the fresh oil, whereas the pH value decreased slightly. GC chromatography and FT-IR analysis results showed that the chemical composition of the bio-oil changed. All the variations indicate that some reactions, such as polymerization, oxidation, polycondensation, hydrolysis of sugars, and esterification, occurred in the bio-oil samples during storage. Bio-oil products stored at 4 °C and room temperature for 4 weeks had relatively high stability, whereas the accelerated aging of bio-oil stored at 50 °C revealed a significant change in its chemical composition. The additional water extraction step specifically improved the stability of the water-insoluble fractions of the bio-oil products. However, the water-soluble fractions were not as stable as the fractions before water extraction. The high content of acid in the water-soluble fractions made it an appropriate medium for hydrolysis sugar and to produce interesting chemical components, 5-(Hydroxymethyl) furfural (HMF), 2(5H)-furanone, furfural, furan, 2,5-dimethyl- and γ-Valerolactone (GVL).

Numerical simulation of flash reduction in a drop tube reactor with variable temperatures

Numerical simulation of flash reduction in a drop tube reactor with variable temperatures

Effect of Woody Biomass Gasification Process Conditions on the Composition of the Producer Gas

Using woody biomass in thermochemical gasification can be a viable alternative for producing renewable energy. The type of biomass and the process parameters influence the producer gas composition and quality. This paper presents research on the composition of the producer gas from the gasification of three woody biomass species: spruce, alder, and pine. The experiments were conducted in a drop-tube reactor at temperatures of 750, 850, and 950 °C, using air as the gasifying agent, with equivalence ratios of 0.38 and 0.19. Gas chromatography with a thermal conductivity detector was used to determine the composition of the producer gas, while the production of total organic compounds was detected using Fourier-transform infrared spectroscopy. All three wood species exhibited very similar producer gas composition. The highest concentration of combustible gases was recorded at 950 °C, with an average of 4.1, 20.5, and 4.6 vol% for H2, CO, and CH4, respectively, and a LHV ranging from 4.3–5.1 MJ/m3. The results were in accordance with other gasification studies of woody species. Higher temperatures enhanced the composition of the producer gas by promoting endothermic and exothermic gasification reactions, increasing gas production while lowering solid and tar yields. The highest concentrations of combustible gases were observed with an equivalence ratio of 0.38. Continuous TOC measurement allowed understanding the evolution of the gasification process and the relation between a higher production of TOC and CO as the gasification temperature raised.

High-temperature gasification of woody biomass in a drop tube reactor: A special focus on the particle size and axial temperature gradient

Pine sawdust (PS) was gasified in a drop-tube reactor (DTR) using air as a gasifying agent. An almost complete mass balance was achieved by establishing a burning operation after gasification to determine the carbon deposits (CD) inside the reactor tube, providing an authentic depiction of the feedstock conversion. The results indicated that particle size reduction led to a significant improvement in the gasification performance. When the particle size of PS was below 0.25 mm, almost complete char gasification was achieved at 1300 °C, while soot remained a major particulate in the syngas. An experimental approach is proposed to simulate the axial temperature gradient (ATG) inside an auto-thermal entrained-flow gasifier by setting two different temperature zones in the DTR. The results revealed that char was rapidly and almost completely exhausted in the high-temperature zone (1300 °C). When the ATG between the upper and lower heater zones was above 300 °C, both homogeneous reforming and heterogeneous gasification proceeded slowly or almost stagnated in the lower temperature zone. An evident enhancement of soot formation was observed at ATG = 200 °C. After that, the soot yield monotonously decreased with decreasing ATG due to the substantial enhancement of the heterogeneous gasification kinetics, contributing more to carbon conversion and CGE than char gasification.

Flash Pyrolysis Kinetics of Extracted Lignocellulosic Biomass Components

Biomass is a complex material mainly composed of the three lignocellulosic components: cellulose, hemicellulose and lignin. The different molecular structures of the individual components result in various decomposition mechanisms during the pyrolysis process. To understand the underlying reactions in more detail, the individual components can be extracted from the biomass and can then be investigated separately. In this work, the pyrolysis kinetics of extracted and purified cellulose, hemicellulose and lignin are examined experimentally in a small-scale fluidized bed reactor (FBR) under N2 pyrolysis conditions. The FBR provides high particle heating rates (approx. 104 K/s) at medium temperatures (573–973 K) with unlimited reaction time and thus complements typically used thermogravimetric analyzers (TGA, low heating rate) and drop tube reactors (high temperature and heating rate). Based on the time-dependent gas concentrations of 22 species, the release rates of these species as well as the overall rate of volatiles released are calculated. A single first-order (SFOR) reaction model and a 2-step model combined with Arrhenius kinetics are calibrated for all three components individually. Considering FBR and additional TGA experiments, different reaction regimes with different activation energies could be identified. By using dimensionless pyrolysis numbers, limits due to reaction kinetics and heat transfer could be determined. The evaluation of the overall model performance revealed model predictions within the ±2σ standard deviation band for cellulose and hemicellulose. For lignin, only the 2-step model gave satisfying results. Modifications to the SFOR model (yield restriction to primary pyrolysis peak or the assumption of distributed reactivity) were found to be promising approaches for the description of flash pyrolysis behavior, which will be further investigated in the future.