Fuel Production Rate Research Articles

Application of Hydroprocessing, Fermentation, and Anaerobic Digestion in a Carbon-Negative Pyrolysis Refinery

This study investigates the economic and environmental benefits of integrating hydroprocessing, fermentation, and anaerobic digestion into a pyrolysis refinery. Two scenarios were developed for upgrading and/or utilizing the primary products of pyrolysis (bio-oil, gas, and char). The first (hydroprocessing) scenario hydroprocesses whole bio-oil into gasoline and diesel. The second (fractionation) scenario fractionates bio-oil into sugars for fermentation to cellulosic ethanol and residual phenolic oil as the primary product. Both scenarios use the gaseous product of pyrolysis for process heat in the plant and employ biochar to enhance anaerobic digestion of manure for power generation. The fast pyrolysis plant processes 2000 ton/day of corn stover while the anaerobic digester employs 430 ton/day of manure to generate power. The hydroprocessing scenario produces gasoline at a minimum fuel-selling price (MFSP) of $2.77 per gallons of gasoline while the fractionation scenario produces ethanol and phenolic oils (diesel) as a transportation fuel for $1.2 per gallon ($1.41 per GGE). Sensitivity analysis indicates that the MFSP for both scenarios is highly sensitive to the fixed capital cost. Fixed capital costs for the hydroprocessing and fractionation scenarios were estimated to be $643 and $288 million, respectively. Fuel production rates for the hydroprocessing and fractionation scenarios are 60.5 and 16 million GGE per year, respectively. Life cycle greenhouse gas emissions were calculated as −9.6 and −16.6 g CO2,eq per MJ for the hydroprocessing and fractionation scenarios, respectively. LCA emissions are sensitive to byproduct credits derived from biochar sequestration and power generation. This study shows that both systems produce transportation fuels at competitive market prices with an additional reduction in atmospheric CO2 levels compared to fossil fuel sources.

Formation of NiCo Alloy Nanoparticles on Co Doped Al2O3 Leads to High Fuel Production Rate, Large Light‐to‐Fuel Efficiency, and Excellent Durability for Photothermocatalytic CO2 Reduction

AbstractUnique nanocomposites of NiCo alloy nanoparticles with Ni/Co molar ratios of 1.86, 1.60, and 0.38 supported on Co‐doped Al2O3 nanosheets are prepared by a facile approach. Very high fuel production rates of CO (rCO) and H2 (rH2) (70.53 and 63.46 mmol min−1 g−1) and light‐to‐fuel efficiency (η, 29.7%) are achieved via photothermocatalytic CO2 reduction by methane (CRM) on Ni1.60Co/Co‐Al2O3 simply utilizing focused UV‐visible‐infrared (UV‐vis‐IR) illumination. Ni1.60Co/Co‐Al2O3 also demonstrates high rCO and rH2 values (50.99 and 39.72 mmol min−1 g−1) as well as high η value (26.3%) under λ > 560 nm focused vis‐IR illumination. The high photothermocatalytic activity is derived from the light‐driven thermocatalytic CRM. A novel photoactivation is found to substantially promote the light‐driven thermocatalytic CRM due to the apparent activation energy being considerably reduced upon illumination. It is found that the Ni/Co molar ratio in the NiCo/Co‐Al2O3 samples has an important effect on the photothermocatalytic durability. The samples of Ni1.60Co/Co‐Al2O3 and Ni1.86Co/Co‐Al2O3 with a higher Ni/Co molar ratio demonstrate excellent photothermocatalytic durability, while the Ni0.38Co/Co‐Al2O3 with a lower Ni/Co molar ratio has less durability. This is attributed to carbon deposition rate being significantly reduced on Ni1.60Co/Co‐Al2O3 and Ni1.86Co/Co‐Al2O3 as compared to its single metal counterparts.

Image analysis of flame behavior for polyolefins and polystyrene in vertical flame test

AbstractAlthough the UL‐94 vertical flame test is often used to evaluate the flammability of polymers based on ignition time and combustion duration parameters, a significant amount of information regarding the time course of combustion is difficult to analyze in detail. Herein, image analysis of the time course of the upper and lower end heights, total area, and color division of flame was performed for polyolefins and polystyrene with different molecular weights in the vertical flame test. The combustion process was classified into two stages: before and after the first drip. In the first stage, the upward spread velocity, oscillation, and color of flame were analyzed. It was assumed that the difference in the fuel production rates or thermal decomposition products depends on the molecular structure. In the second stage, the melt flowability, flame position, and combustion continuity differed vastly depending on the molecular structure or molecular weight.

Two-step CO2 and H2O splitting using perovskite-coated ceria foam for enhanced green fuel production in a porous volumetric solar reactor

Solar thermochemical cycles offer a viable option for the production of green synthetic fuels from CO2 and H2O. Two-step cycles using redox materials consist of a high-temperature reduction creating oxygen vacancies, followed by a re-oxidation step with an oxidant gas (CO2 and/or H2O), resulting in CO and/or H2 production. This study focuses on the thermochemical performance in a solar reactor of a new kind of composite reactive material: reticulated ceria foam with uniform perovskite coating, forming a dual-phase layered heterostructure. La0.5Sr0.5Mn0.9Mg0.1O3 (LSMMg) was selected as perovskite coating due to its high fuel productivity and thermochemical stability upon cycling. The perovskite coating improves the reduction step by increasing the reduction extent reached by the reactive material. The results revealed significant enhancement of oxygen exchange in the dual-phase composite material during reduction compared to individual components. The enhanced reduction extent had a beneficial effect on the oxygen release rate and the total amount of fuel produced by CO2 and H2O splitting, whereas an adverse impact on the peak rate during H2/CO evolution was noticed. Decreasing the reduction pressure allowed enhancing the non-stoichiometric oxygen extent, while the re-oxidation extent increased with the inlet oxidant molar fraction. With suitable operating conditions (reduction at 0.100 bar and oxidation in 100 % CO2), the LSMMg-coated ceria foam produced a higher amount of fuel but with lower fuel production rate in comparison with pure ceria foam. This study points out the beneficial effects of composite redox materials consisting of LSMMg-coated ceria foam in enhancing the oxygen exchange capacity of ceria for solar fuel production.

Solar thermochemical fuel production from H2O and CO2 splitting via two-step redox cycling of reticulated porous ceria structures integrated in a monolithic cavity-type reactor

Solar thermochemical H2O and CO2 splitting cycles represent an efficient route for converting high temperature concentrated solar heat into valuable chemical energy carriers (solar fuels). A new monolithic solar reactor compatible with ceria redox reactions was designed, constructed and tested under concentrated solar radiation. The ceria redox material was shaped and integrated as reticulated porous structures with controlled cell sizes and gradient (10–60 ppi, pores per inch) enabling efficient volumetric solar radiation absorption and micro-scale interconnected porosity favouring the solid-gas reactions. Temperature-swing redox cycling experiments were performed to demonstrate solar reactor reliability during continuous operation. The foams were first thermally activated by increasing the reactor temperature (1400–1450 °C) for O2 release and then exposed to H2O or CO2 stream to produce pure H2 or CO (700–1100 °C), allowing cyclic operation in the same reactor. The influence of operating conditions (including reduction and oxidation temperatures, pressure and type of oxidizing gas) on reactor performance was investigated. An increase of the reduction temperature or a decrease of the operating pressure improved both the ceria reduction extent and fuel production yields (up to 341 μmol/g), while a decrease of the CO:CO2 ratio (by increasing total inlet gas flow-rate) or an increase of the inlet CO2 concentration enhanced oxidation rates (up to 9.3 mL/g/min). The obtained fuel production rates outperformed the maximum previously reported values by up to 8 times using the highly-reactive manufactured ceria porous foams cycled between 1400 °C and 900 °C with oxidation performed in 100% CO2 upon dynamic cooling. An average H2/CO production of ∼280 Ncm3/cycle (64 cycles performed) was achieved with solar-to-fuel efficiency up to ∼7.5% and remarkable material performance stability.

Remarkable performance of microstructured ceria foams for thermochemical splitting of H2O and CO2 in a novel high–temperature solar reactor

Thermochemical splitting of H2O and CO2 applying redox materials constitutes a sustainable option for synthetic fuel production and CO2 valorization. It consists of two-step process based on the creation of oxygen vacancies in non-stoichiometric oxides during solar-driven thermal reduction, followed by the material re-oxidation with H2O and/or CO2 to generate syngas (H2/CO), the building block for a wide variety of synthetic hydrocarbon fuels. In this work, a monolithic solar reactor was designed and tested integrating reticulated porous ceria (open-cell foams) heated by concentrated solar energy. The influence of various operating parameters on the thermochemical reactor performance was investigated. Increasing the temperature or decreasing the pressure in the reduction step was found to enhance the maximum reduction extent reached by the redox material (CeO2-δ), thereby improving the fuel production capacity. In addition, a decrease of the oxidation temperature led to higher fuel production rate, despite an increase of the temperature swing between the reduction and oxidation steps. Increasing the oxidant concentration also sharply enhanced the oxidation rate. Peak CO production rate approaching 10 mL/min/g was achieved with ceria foams (exhibiting micron-sized grains forming an interconnected macroporous network within the struts) during their reoxidation upon free cooling with pure CO2 stream (after reduction at 1400 °C), thus strongly outperforming (by a factor of about x8) the previous maximum values reported to date. This result was attributed to the fine and stable granular microstructure of the reticulated ceria foams. The solar reactor reliability and robustness during high-temperature two-step redox cycling were demonstrated with an average cycle production of 5.1 mL/g of H2 and CO, and peak solar-to-fuel efficiencies above 8%. The highly reactive reticulated foams with 10 and 20 ppi (pore per inch) were cycled for about 69 h (51 cycles) of continuous on-sun operation without any decrease in performance, thus evidencing their noteworthy thermochemical and microstructural stability.

(Invited) Thermochemical Properties of Non-Stoichiometric Oxides for Solar Fuel Generation

Solar-driven thermochemical production of chemical fuels using redox active oxides has emerged as an attractive means for storing solar energy for subsequent use on demand. In this process a reactive oxide is cyclically exposed at high temperatures to an inert gas, which induces partial reduction of the oxide, and to an oxidizing gas of either H2O or CO2, which oxidizes the oxide, releasing H2 or CO. The capacity for fuel production is dictated by the thermodynamic properties of the oxide, specifically the enthalpy and entropy of reduction. Less appreciated is the fact that the fuel production rate is also highly dependent on the thermodynamic properties. Here we review progress made in measuring the thermodynamic functions for a range of materials and in identifying suitable thermodynamic values for efficient fuel production.

Electrolytic Performance of a Cathode-Supported Honeycomb Solid Oxide Electrolysis Cell

Power Gas technology has recently been of great attention to convert electric power from renewable energy such as solar and wind powers to fuel for energy storage and transport. Steam electrolysis and co-electrolysis by the Solid Oxide Electrolysis Cell (SOEC) are expected to play an important role. We have developed a honeycomb electrolytic cell for a larger reactive area per unit volume than the conventional planar and tubular cells. Thereby density of fuel production rate can be significantly improved, leading to a development of compact and high performance steam electrolysis systems. In the present study, we assess hydrogen production by steam electrolysis with an SOEC having a porous honeycomb support consisting of Ni-YSZ cathode. The cathode and anode were supplied with H2O/N2/H2 mixture and air, respectively. The cathode was composed of eight flow channels and the anode was of a single channel in the cell. Current-voltage curves were measured, while increased current led to an increase in hydrogen concentration in the sampled gas from the cathode outlet determined by gas chromatography. The experimental results are useful to develop validated numerical models to design practical honeycomb cells.

Fuel Production with a Cathode-Supported Honeycomb Solid Oxide Electrolysis Cell

In recent years, the establishment of Power to Gas technology is in progress. Promising methods include steam electrolysis and co-electrolysis using the Solid Oxide Electrolysis Cell (SOEC). We have developed a honeycomb electrolytic cell with a larger reactive area per unit volume than the conventional flat and tubular types. Thereby volumetric density of fuel production rate can be greatly improved, leading to a development of compact and high performance steam electrolysis systems. In this study, we address hydrogen production by steam electrolysis with an SOEC having a porous honeycomb support consisting of Ni-YSZ cathode. Current-voltage curves were measured with sampling the cathode outlet gas for gas chromatography. As the results, we confirmed that hydrogen concentration in the outlet increased as the current increased. The experimental results are useful to validate numerical models to design practical honeycomb cells.

UV-vis-IR irradiation driven CO2 reduction with high light-to-fuel efficiency on a unique nanocomposite of Ni nanoparticles loaded on Ni doped Al2O3 nanosheets

A nanocomposite of Ni/Ni-Al2O3 nanosheets exhibits a high fuel production rate and light-to-fuel efficiency for photothermocatalytic CO2 reduction with CH4.

High light-to-fuel efficiency and CO2 reduction rates achieved on a unique nanocomposite of Co/Co doped Al2O3 nanosheets with UV-vis-IR irradiation

A nanocomposite of Co/Co–Al2O3 nanosheets shows a high light-to-fuel efficiency and fuel production rate for photothermocatalytic CO2 reduction using CH4.

Solar thermochemical CO2 splitting using cork-templated ceria ecoceramics

This work addresses the solar-driven thermochemical production of CO and O2 from two-step CO2-splitting cycles, using both ceria granules prepared from cork templates (CG) and ceria foams from polyurethane templates (CF). These materials were cycled in a high-temperature indirectly-irradiated solar tubular reactor using a temperature-swing process. Samples were typically reduced at 1400 °C using concentrated solar power as a heating source and subsequently oxidised with CO2 between 1000–1200 °C. On average, CO production yields for CG were two times higher than for CF, indicating that the morphology of this three-dimensionally ordered macroporous (3-DOM) CeO2 improves the reaction kinetics. Their performance stability was demonstrated by conducting 11 cycles under solar irradiation conditions. Slightly increasing the reduction temperature strongly enhanced the reduction extent, and thus the CO production yield (reaching about 0.2 mmol g−1 after reduction at 1450 °C in inert gas), while decreasing the oxidation temperature mainly improved the CO production rate (up to 1.43 μmol s−1 g−1 at 1000 °C). Characterisation of the 3-DOM structure, by means of XRD and SEM, provided insights into the reactivity behaviour of the developed materials. The pre-sintered ceria granules retained their structure after cycling. The fact that the mean cell size of CG is smaller (at least one order of magnitude) than that of CF suggests that its exposed surfaces enhanced reaction rates by a factor of two. Moreover, the maximum fuel production rate of CG was roughly three times greater than that reported previously for a ceria reticulated porous foam with dual-scale porosity.

Earth-abundant transition metal oxides with extraordinary reversible oxygen exchange capacity for efficient thermochemical synthesis of solar fuels

Efficient storage of solar and wind power is one of the most challenging tasks still limiting the utilization of the prime but intermittent renewable energy sources. The direct storage of concentrated solar power in renewable fuels via thermochemical splitting of water and carbon dioxide on a redox material is a scalable approach with up to 54% solar-to-fuel conversion efficiency. Despite progress, the search for earth-abundant materials that can provide and maintain high H2 and CO production rates over long period of high-temperature cycles continues. Here, we report a strategy to unlock the use of manganese, the 12th most abundant element in the Earth's crust, for thermochemical synthesis of solar fuels, achieving superior thermochemical stability, oxygen exchange capacity, and up to seven times higher mass-specific H2 and CO yield than cerium dioxide. We observe that incorporation of a small fraction of cerium ions in the manganese (II,III) oxide crystal lattice drastically increases its oxygen ion mobility, allowing its reduction from oxide to carbide during methane partial oxidation with simultaneous Ce exsolution. High CO2 and H2O splitting rates are achieved by re-oxidation of the carbide to manganese (II) oxide with simultaneous reincorporation of the cerium ions. We demonstrate that the oxide to carbide reaction is highly reversible achieving remarkable CO2 splitting rates over 100 thermochemical cycles of methane partial oxidation and CO2 splitting, and preserving the initial oxygen exchange capacity of 0.65 molOmolMn−1 and 89% of the fuel production rates. Due to this extraordinarily high reversible oxygen exchange capacity, the 3% Ce-doped manganese oxide achieves an average mass-specific CO yield for CO2 splitting of 17.72 mmolCO g−1, which is significantly higher than that previously achieved in thermochemical redox cycles. More generally, these findings suggest that incorporation of small soluble amounts of cerium in earth-abundant transition metal oxides like manganese oxide is a powerful approach to enable solar thermochemical fuel synthesis.

Pyrolysis of plastic waste for production of heavy fuel substitute: A techno-economic assessment

Pyrolysis is widely seen as a promising technology for converting plastic waste into a wax/oil product which can be used as a heavy fuel oil substitute or as raw material by the petrochemical industry. A pyrolysis plant with a capacity of 100 kg/h plastic waste is modelled in the process simulation software Aspen HYSYS. The production costs of the pyrolysis fuel product is estimated at £0.87/kg which is 58% higher than current market prices; therefore, a scaling-up analysis is also carried out to determine the plant capacity for which the pyrolysis process is economically feasible. The fuel production costs of the scaled-up cases considered are approximately 2.2–20.8 times lower than the existing market prices of residual fuel oil, indicating their economic feasibility. For the 1000 kg/h and 10,000 kg/h plant capacity cases the facility needs to operate approximately four years and one year respectively, to recover the capital investment, while the 100,000 kg/h case produces revenue and has a positive NPV within year one. A sensitivity analysis is also carried out revealing that the fuel production rate is the most sensitive parameter for the 100 kg/h plant, as well as the scaled-up plants.

Downdraft Co-gasification of Oil Palm Frond with Other Oil Palm Residues: Effects of Blending Ratio

As the largest amount of biomass residues produced from the palm oil industry, the oil palm frond (OPF) is a promising solid fuel resource for gasification. However, the difficulty in processing OPF into solid fuel may affect the solid fuel production rate and consequently the gasifier operation. To ensure a continuous gasifier operation unaffected by the shortage of OPF fuel, empty fruit bunch (EFB), palm mesocarp fiber (PMF) and palm kernel shell (PKS) were introduced as a pairing fuel with OPF for co-gasification. The potentials of the fuel mixes and the effects of the fuel blending ratio on syngas higher heating value, specific syngas yield, carbon conversion efficiency and cold gas efficiency were studied. The experiments concluded that all fuel mixes of all blending ratios satisfied all the syngas quality indicator requirements and that all the tested fuel mixes can be utilized for downdraft co-gasification to produce results similar to the downdraft gasification of 100% OPF.

Impact of enhanced oxide reducibility on rates of solar-driven thermochemical fuel production

Two-step, solar-driven thermochemical fuel production offers the potential of efficient conversion of solar energy into dispatchable chemical fuel. Success relies on the availability of materials that readily undergo redox reactions in response to changes in environmental conditions. Those with a low enthalpy of reduction can typically be reduced at moderate temperatures, important for practical operation. However, easy reducibility has often been accompanied by surprisingly poor fuel production kinetics. Using the La_(1−x) Sr_x MnO_3 series of perovskites as an example, we show that poor fuel production rates are a direct consequence of the diminished enthalpy. Thus, material development efforts will need to balance the countering thermodynamic influences of reduction enthalpy on fuel production capacity and fuel production rate.

A thermodynamic work cycle simulation of a syngas-fueled engine

A syngas-fueled engine work cycle simulation has been conducted in the AVL BOOST environment in order to gain some insights into the expected engine performance and efficiency parameters. The study also provides the energy balance that will dictate the design of engine coolant and exhaust gas heat recuperation systems. A turbocharged six-cylinder gas engine serves as the basis on which the numerical studies have been conducted. A Vibe-based heat release model, customized to take into account the effect of excess-air ratio and ignition timing variations on the combustion duration and MFB curve shape is used to predict the heat release rate. A simple methodology for determining the total engine displacement for a given fuel production rate is also presented. The resulting brake mean effective pressure and efficiency parameters are lower than on a comparable natural gas-fueled engine but syngas is still an interesting alternative, particularly for cogeneration units.

Maximizing fuel production rates in isothermal solar thermochemical fuel production

Production of chemical fuels by isothermal pressure-swing cycles has recently generated significant interest. In this process a reactive oxide is cyclically exposed to an inert gas, which induces partial reduction of the oxide, and to an oxidizing gas of either H2O or CO2, which reoxidizes the oxide, releasing H2 or CO. At sufficiently high temperatures and sufficiently low gas flow rates, both the reduction and oxidation steps become limited only by the flow of gas across the material and not by material kinetic factors. In this contribution, we develop a numerical model describing fuel production rates in this gas-phase limited regime. The implications of this behavior are explored under all possible isothermal pressure-swing cycling conditions, and the outcome is optimized in terms of fuel production rate as well as fuel conversion and utilization of input gas of all types. Fuel production rate is maximized at infinitesimally small cycle times and attains a value that is independent of material thermodynamics. Gas utilization is maximized at infinitesimally small gas inputs, but the values can be made independent of cycle time, depending on manipulation of flow conditions. Gas-phase conditions (temperature, oxidant and reductant gas partial pressures, and CO2 vs H2O as oxidant) have a strong impact on fuel production metrics. Under realistic, finite cycle times, material thermodynamics play a measurable role in establishing fuel production rates.

The Impact of Strong Cathodic Polarization on SOC Electrolyte Materials

One of the most promising reversible energy conversion/storage technologies is that of Solid Oxide Fuel/Electrolysis Cells (SOFC/SOEC, collectively termed SOC). Long term durability is typically required for such devises to become economically feasible, hence considerable amount of work has and is being done on the degradation and long term durability of these systems. When using a SOC in electrolysis mode, it is economically beneficial to operate the cell at high current density, since it increases the fuel production rate. However, several degradation phenomena, such as segregation of impurities at the grain boundaries, electrode poisoning, delamination or cracks of the electrolyte etc., have been observed in cells operated at such conditions, lowering the lifetime of the cell1,2. High polarizations are observed at the electrolyte/cathode interface of an electrolysis cell operated at high current density. In case of a cell voltage above 1.6 V, p-type and n-type electronic conductivity are often observed at the anode and cathode respectively3. Hence, a considerable part of the current is lost as leakage through the electrolyte, thus lowering the efficiency of the cell considerably. The presented work aims to study the impact of short term strong cathodic polarization in SOC model systems PtIr/YSZ and Ni/YSZ. The study is mainly focused on electrolyte materials such as yttria stabilized zirconia (YSZ). Since impurity segregation is one of the suggested degradation mechanisms, electrolyte materials with silica additions are investigated likewise. The electrochemistry of the electrolytes is studied in a Controlled Atmosphere High Temperature Scanning Probe Microscope (CAHT-SPM)4,5, using PtIr (8:2) or Ni probes as working electrodes. Different cathodic polarizations ranging from -0.1 V to -2 V vs. a macroscopic platinum reference electrode in the same atmosphere are applied to the YSZ electrolyte at 650 °C through the well-defined tip of the probe. The atmosphere used for these measurements is a mixture of 9% H2 in N2 saturated with water vapor at room temperature. The electrochemical impedance spectroscopy measurements, in addition to the expected change in the DC resistance, reveal a decrease in the series resistance (Rs) with increasing cathodic polarization (Figure 1a, 1b). Such decrease in the ohmic resistance of the electrolyte indicates the introduction of electronic conductivity in the electrolyte material. The measurements presented in Figure 1 are obtained from stepwise cathodic polarization ranging from -0.2 V to -2 V with a conditioning period of 120 s before each impedance scan on a dense YSZ electrolyte using a nickel probe as working electrode. Similar behavior of the Rshas been obtained using PtIr probes. In addition to the electrochemical study, the chemistry, microstructure and surface conductance of the region impacted from the polarization are investigated using Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS), Scanning Electron Microscopy (SEM) and CAHT-SPM. The surface conductance measurements for the PtIr-YSZ model system show that the impact of the polarization is larger than the tip-electrolyte contact area. The presence of the high and low conductance regions is attributed to the introduction of electronic conductivity, the segregation of impurities/low conducting phases and the microstructural changes in the material. The affected area is strongly dependent on the time and strength of the polarization. Such trends are also observed in the chemistry and microstructure of the surface. The nickel ion image obtained with ToF-SIMS (Figure 1c) gives an indication of the tip-sample contact area, since the formation of Ni-Zr compounds has been previously observed. The siliconion image on the other hand, demonstrates that silicon species segregate in a much larger region surrounding the contact area. The silicon ion signal is attributed to silica, since the polarization applied is lower than the silica reduction potential. Thus, by combining all of the above techniques, valuable information is obtained about multiple degradation mechanisms caused from strong cathodic polarization.

Model of transport and chemical kinetics in a solar thermochemical reactor to split carbon dioxide

Solar thermochemical reactors to carry out the nonstoichiometric reduction and oxidation of cerium dioxide (ceria) to split water and carbon dioxide provide a pathway to store sunlight in a chemical fuel. One of the challenges in the design of these reactors is understanding the complex coupling of heat and mass transfer and redox chemistry. To elucidate this coupling, we present a three-dimensional, transient model of a recently developed prototype solar reactor that implements an isothermal, pressure-swing ceria redox cycle. Radiative transport is modeled by a hybrid Monte Carlo/finite volume approach and paired with the transport and chemical processes within a fixed bed of porous ceria particles. Morphology specific reaction rate coefficients for the gas–solid reactions in ceria are extracted for the first time from global rate measurements in a bench-top reactor at 1773K. Results demonstrate the interdependent spatial and temporal variations in temperature, species concentration and reaction rates, and provide insight on the effects of optical properties on reactor performance. For a solar input of 4.2kW, the reactor achieves nearly isothermal cycling at 1791K with carbon monoxide produced continuously at 3.6×10−4mols−1. At this temperature, global reaction rates are driven by advective mass transport rates and the intrinsic material thermodynamics. Predicted surface temperatures and fuel production rates compare favorably to measured data.