Thermochemical Hydrogen Production Research Articles

Exergy analysis of Cobalt–Chlorine thermochemical hydrogen production cycle: A kinetic approach

Increasing energy needs and reducing greenhouse gas emissions require immediate studies on carbon-free energy solutions, namely hydrogen. There are numerous methods among the production methods of hydrogen in a green manner. Hydrogen, which is then primarily obtained as a result of the separation of water with thermochemical cycles, is an environmentally friendly and sustainable hydrogen production method. In this study, the Cobalt–Chlorine (Co–Cl) cycle, which is one of the new thermochemical cycles, is examined in detail in terms of thermodynamics. There are four reactions in the Co–Cl thermochemical cycle. These are listed as the hydrolysis reaction in which hydrogen is obtained, the thermolysis reaction in which oxygen is obtained, the reduction reaction and finally the hydrochlorination reaction. According to the results of the analysis performed kinetically with the Aspen Plus software, the exergy efficiency of the cycle is calculated as 33%. When the exergy destruction of all reactions is compared, it is seen that the greatest exergy destruction occurs in the hydrolysis reaction, and the lowest exergy destruction occurs in the hydrochlorination reaction. The fact that the exergy efficiency is high when evaluated in terms of kinetics shows that the cycle is feasible in terms of thermodynamics. In addition, the costs of the cycle are to be considered in the future studies as it is an important criterion.

A novel fluidized bed suitable for the hydrolysis step in CuCl hydrogen production cycle

In this paper, a novel design for a hydrolysis reactor step in the Cu–Cl thermochemical hydrogen production cycle is presented and investigated.The core concept of this hydrolysis reactor is recirculation of reaction steam, hence the name “Recirculating Steam Fluidized Bed” (RSFB). This design recirculates steam through the fluidized bed allowing for the unused steam to be consumed by the reaction. This design was found to reduce the total thermal energy requirement of the hydrolysis step by 50% while maintaining favorable reaction kinetics. The recirculating steam has the added benefit of increasing the concentration of product HCl, allowing for a more productive integration with downstream processes. Given the results presented here, it is suggested that the RSFB reactor be considered for adoption in the Cu–Cl cycle scale-up efforts.

Modulating the O-binding Energies of Mn-based Perovskites to Maximize Solar Thermochemical Hydrogen Production

Modulating the O-binding Energies of Mn-based Perovskites to Maximize Solar Thermochemical Hydrogen Production

Predicting the formation of fractionally doped perovskite oxides by a function-confined machine learning method

Fractionally doped perovskites oxides (FDPOs) have demonstrated ubiquitous applications such as energy conversion, storage and harvesting, catalysis, sensor, superconductor, ferroelectric, piezoelectric, magnetic, and luminescence. Hence, an accurate, cost-effective, and easy-to-use methodology to discover new compositions is much needed. Here, we developed a function-confined machine learning methodology to discover new FDPOs with high prediction accuracy from limited experimental data. By focusing on a specific application, namely solar thermochemical hydrogen production, we collected 632 training data and defined 21 desirable features. Our gradient boosting classifier model achieved a high prediction accuracy of 95.4% and a high F1 score of 0.921. Furthermore, when verified on additional 36 experimental data from existing literature, the model showed a prediction accuracy of 94.4%. With the help of this machine learning approach, we identified and synthesized 11 new FDPO compositions, 7 of which are relevant for solar thermochemical hydrogen production. We believe this confined machine learning methodology can be used to discover, from limited data, FDPOs with other specific application purposes.

Which thermochemical water-splitting cycle is more suitable for high-temperature concentrated solar energy?

The manuscript reviews the thermochemical water-splitting cycles not in general (many other works have covered this topic) but specifically for producing hydrogen coupled with high temperature concentrated solar energy which is available at temperatures of 1000 to 1100 °C. This is important to benefit from synergies with near future dispatchable concentrated solar power, simply replacing the power cycle with the thermochemical hydrogen production plant. The review shows as three-step cycles are those benefiting the most from the synergy with higher solar flux dispatchable concentrated solar power with thermal energy storage, also profiting in terms of technology readiness level from past experiences in thermochemical water-splitting cycles for nuclear power plants, and the affordable complexity of the cycle. From preliminary evaluations, three-step cycles may permit CO2-free hydrogen production within a decade at a competitive cost with green hydrogen as well as the current prevailing production of hydrogen from hydrocarbons at less than $1 per 1 kg. The thermochemical pathway has the same minimum energy requirement as electrolysis, despite the conversion efficiencies achieved so far have been much less because of the reduced development. Since the collection of solar thermal energy is much easier and more efficient than solar photovoltaic conversion, the thermochemical pathway has the potential to deliver a cost of hydrogen smaller than green hydrogen from solar photovoltaic electricity and electrolyzers.

Formation of 6H-Ba3Ce0.75Mn2.25O9 during Thermochemical Reduction of 12R-Ba4CeMn3O12: Identification of a Polytype in the Ba(Ce,Mn)O3 Family.

The resurgence of interest in a hydrogen economy and the development of hydrogen-related technologies has initiated numerous research and development efforts aimed at making the generation, storage, and transportation of hydrogen more efficient and affordable. Solar thermochemical hydrogen production (STCH) is a process that potentially exhibits numerous benefits such as high reaction efficiencies, tunable thermodynamics, and continued performance over extended cycling. Although CeO2 has been the de facto standard STCH material for many years, more recently 12R-Ba4CeMn3O12 (BCM) has demonstrated enhanced hydrogen production at intermediate H2/H2O conditions compared to CeO2, making it a contender for large-scale hydrogen production. However, the thermo-reduction stability of 12R-BCM dictates the oxygen partial pressure (pO2) and temperature conditions optimal for cycling. In this study, we identify the formation of a 6H-BCM polytype at high temperature and reducing conditions, experimentally and computationally, as a mechanism and pathway for 12R-BCM decomposition. 12R-BCM was synthesized with high purity and then controllably reduced using thermogravimetric analysis (TGA). Synchrotron X-ray diffraction (XRD) data is used to identify the formation of a 6H-Ba3Ce0.75Mn2.25O9 (6H-BCM) polytype that is formed at 1350 °C under strongly reducing pO2. Density functional theory (DFT) total energy and defect calculations show a window of thermodynamic stability for the 6H-polytype consistent with the XRD results. These data provide the first evidence of the 6H-BCM polytype and could provide a mechanistic explanation for the superior water-splitting behaviors of 12R-BCM.

A Thermogravimetric Temperature-Programmed Thermal Redox Protocol for Rapid Screening of Metal Oxides for Solar Thermochemical Hydrogen Production

As combinatorial and computational methods accelerate the identification of potentially suitable thermochemically-active oxides for use in solar thermochemical hydrogen production (STCH), the onus shifts to quickly evaluating predicted performance. Traditionally, this has required an experimental setup capable of directly carrying out a two-stage thermochemical water-splitting process. But this can be a difficult endeavor, as most off-the-shelf equipment cannot adequately deal simultaneously with the high temperatures, varying oxygen partial pressures, and high H2O partial pressures required; achieving sufficient temporal sensitivity to accurately quantify the kinetics is also a major challenge. However, as proposed here, a less complicated experiment can be used as a first screening for thermochemical water splitting potential. Temperature-Programmed Thermal Redox (TPTR) using thermogravimetry evaluates the thermal reduction behavior of materials. This technique does not require water splitting or CO2-splitting analogs but can nonetheless predict water-splitting performance. Three figures of merit are obtained from the TPTR experiment: reduction onset temperature, extent of reduction, and extent of recovery upon reoxidation. These metrics can collectively be used to determine if a material is capable of thermochemical water-splitting, and, to good approximation, predict whether the thermodynamics are favorable for use under more challenging high-conversion conditions. This paper discusses the pros and cons of using TPTR and proposes a protocol for use within the STCH community.

Optimizing the operational strategy of a solar-driven reactor for thermochemical hydrogen production

In this paper the operational strategy of a pilot plant for regenerative hydrogen production based on two-step thermochemical redox cycles is investigated with focus on optimal operational parameters for highest solar-to-fuel efficiency. The current plant consists of a solar driven large-scale 250 kW thermochemical inert gas reactor using ceria as reactive material for water splitting and an efficient fluid heat recovery system. Here we analyse the most important process conditions, which are operating temperatures, mass flow rates and duration times for both steps in the cycle. A highly accurate and detailed simulation model combined with well-suited optimization routines reveals new insights in most efficient operational strategies. Within the optimization material and technical limits of the used components are considered, thereby yielding reliable practical results. Optimal operational parameters are found by using a temperature swing strategy with corresponding solar-to-fuel plant efficiency determined by up to 1.1%.

System and technoeconomic analysis of solar thermochemical hydrogen production

Hydrogen is a promising energy carrier that can be obtained from various feedstocks using renewable energy sources. Direct solar thermochemical hydrogen (STCH) production by water splitting can utilize the full spectrum of solar radiation and has the potential to achieve high solar energy conversion efficiencies. Currently STCH research areas focus on material discovery. This paper evaluates the performance of various STCH materials in the context of a system platform to assess techno-economic benefits and gaps in the path to STCH scale-up. To analyze the hydrogen production cost, a concentrating solar thermal (CST) system is introduced as a platform for integrating STCH materials and accommodating generalized thermochemical processes. The thermochemical process is based on a two-step STCH cycle using metal oxide that consists of a high temperature step for metal oxide reduction, followed by an oxidation step for water splitting at a lower temperature. A preferred configuration is to have the high temperature step occurring in a directly irradiated solar receiver reactor. To this end, we conceptualized a receiver design and associated solar field layout and investigated STCH operational boundaries, component costs and sensitivity parameters on the $2/kgH2 goal of hydrogen production. The study explored system-related variables and factors associated with scaling up. The CST platform allows more comprehensive studies that encompass aspects of STCH materials and systems such as cost, hydrogen productivity and replacement frequency, alongside other system components like heliostat field, tower, and potential receiver costs.

A newly developed solar-based cogeneration system with energy storage and heat recovery for sustainable data centers: Energy and exergy analyses

There is a strong need and hence specific challenges attached to this for data centers to bring holistic energy solutions for better operation, control and management in a more cost-effective, efficient and environmentally benign manner. The current study develops and investigates a solar-based novel integrated system to generate electricity and hence provide cooling in a sustainable way. The proposed system includes a parabolic trough-type concentrated solar plant with a Rankine cycle, bifacial photovoltaic plant, proton exchange membrane (PEM) fuel cell, PEM electrolyzer, Cu-Cl thermochemical hydrogen production cycle, Li-Br absorption refrigeration cycle. In order to prevent solar intermittency, thermal and chemical-based energy storage systems are integrated as molten salt cold and hot thermal energy storage tanks and hydrogen-based energy storage systems. The heat is recovered by the Rankine cycle and the Li-Br absorption refrigeration cycle in order to generate electricity and to provide cooling. The overall system is analyzed with thermodynamic approaches from the energy and exergy points of view. For further, the overall system is analyzed with the hourly ambient data in a time-dependent analysis for a data center in Calgary, Alberta, Canada. For the average ambient conditions, the energy and exergy efficiencies of the overall integrated system calculated as 35.98% and 31.24%, respectively. At least 10% of the overall energy efficiency is exceeded during a total of 8091 h of the year, whereas the overall exergy efficiency is exceeded 10% during the 7726 h in a year. Further to note that there are challenges for such systems to bring a holistic solution.

A comprehensive comparative energy and exergy analysis in solar based hydrogen production systems

In the presented paper, energy and exergy analysis is performed for thermochemical hydrogen (H 2 ) production facility based on solar power. Thermal power used in thermochemical cycles and electricity production is obtained from concentrated solar power systems. In order to investigate the effect of thermochemical cycles on hydrogen production, three different cycles which are low temperature Mg–Cl, H 2 SO 4 and UT-3 cycles are compared. Reheat-regenerative Rankine and recompression S–CO 2 Brayton power cycles are considered to supply electricity needed in the Mg–Cl and H 2 SO 4 thermochemical cycles. Furthermore, the effects of instant solar radiation and concentration ratio on the system performance are investigated. The integration of S–CO 2 Brayton power cycle instead of reheat-regenerative Rankine enhances the system performance. The maximum exergy efficiency which is obtained in the system with Mg–Cl thermochemical and recompression S–CO 2 Brayton power cycles is 27%. Although the energy and exergy efficiencies decrease with the increase of the solar radiation, they increase with the increase of the concentration ratio. The highest exergy destruction occurred in the solar energy unit. • Energy and exergy efficiencies of solar based hydrogen production system are investigated. • Low temperature Mg–Cl, H 2 SO 4 and UT-3 cycles are compared. • Reheat-regenerative Rankine or supercritical-CO 2 Brayton power cycle is integrated. • The system with Mg–Cl and s-CO 2 Brayton power cycles has maximum exergy efficiency. • The exergy efficiency increases with the increase of the concentration ratio.

Investigation of a new integrated energy system with thermochemical hydrogen production cycle and desalination

This study presents design, development and analysis of a novel integrated energy system based on renewable geothermal energy source with a Copper Chlorine (CuCl) thermochemical cycle for hydrogen production production and a multistage desalination subsystem for freshwater production. In the proposed system, five useful outputs are effectively generated, such as heat for space heating, electricity, freshwater, hot water and hydrogen. CuCl thermochemical cycle is used for hydrogen production. The need for achieving high-temperature levels for the thermochemical cycle is met by a CuCl cascaded heat pump configuration in the system. The presented system is further analyzed and assessed thermodynamically through energy and exergy approaches. A case study is conducted for the city of Vancouver, Canada. Some parametric studies are also performed to observe the effects of different ambient and working conditions for the overall system and subsystems. According to conducted thermodynamic analysis, 42.06% energy and 49.65% exergy efficiencies are obtained for the overall system. The total exergy destruction rate for the overall system components is determined to be 46.56 MW. In the CuCl-Mercury cascaded heat pump configuration, the coefficient of performance values are obtained as 1.557 for energy and 1.128 for exergy.

Assessment and multi-objective optimization of a vanadium-chlorine thermochemical cycle integrated with algal biomass gasification for hydrogen and power production

A cogeneration energy system for green hydrogen and power production from algal biomass and water as renewable sources is first developed and analyzed with engineering equation solver (EES) through first and second law of thermodynamics and then, optimized through an evolutionary algorithm using the Matlab software package for higher exergy efficiency, lower cost, and lower environmental impact. The vanadium-chlorine (V-Cl) thermochemical cycle is selected for hydrogen production incorporated into cogeneration system. A novel integration of a three-step V-Cl thermochemical cycle, a Brayton power generation cycle and a biomass gasification unit fed by Cladophora glomerata macroalgae as a marine biomass is proposed and investigated in this study. Both exergoeconomic and exergoenvironment analyses are developed to evaluate the performance of the proposed cogeneration system. Also, both power generation system and thermochemical hydrogen production cycle are validated with previous studies in the literature for more accuracy. The proposed system is able to produce a 23.42 kg/h of hydrogen and a total of 885 kW power at the base case condition. Moreover, optimum values for overall exergy efficiency, total cost per unit of exergy, and environmental impacts are 60.45%, 14.46 g.CO2/kWh, 6.36 $/GJ, respectively, where pressure ratio (for Brayton cycle) is 5.87, gasification temperature is 715 °C and biomass mass flow rate is 0.8 kg/s.

A review on integrated thermochemical hydrogen production from water

Hydrogen production from water splitting is considered one of the most environmentally friendly processes for replacing fossil fuels. Among the various technologies to produce hydrogen from water splitting, thermochemical cycles using chemical reagents have the advantage of scale up compared to other specific facilities or geological conditions required. According to thermochemical processes using chemical redox reactions, 2-, 3-, 4-step thermochemical water splitting cycles can generate hydrogen more efficiently due to reducing temperatures. Increasing the number of cycles or steps of thermochemical hydrogen production could reduce the required maximum temperature of the facility. In addition, recently developed hybrid thermochemical processes combined with electricity or solar energy have been studied on a large scale because of the reduced cost of hydrogen production. Additionally, hybrid thermochemical water splitting combined with renewable energy can result in not only reducing the cost, but also increasing hydrogen production efficiency in terms of energy. As for a green energy, hydrogen production from water splitting using sustainable and renewable energy is significant to protect biological environment and human health. Additionally, hybrid thermochemical water splitting is conducive to large scale hydrogen production. This paper reviews the multi-step and highly developed hybrid thermochemical technologies to produce hydrogen from water splitting based on recently published literature to understand current research achievements.

Assessment study of a four-step copper-chlorine cycle modified with flash vaporization process for hydrogen production

This paper develops a four-step copper-chlorine cycle for hydrogen production with conceptual modification through flash vaporization and evaluates its economic and environmental performances through exergy approach. The flash vaporization method is employed as a new approach for realizing the anolyte separation under vacuum conditions for reducing the thermal requirement of the anolyte separation step and consequently of the overall cycle. A flash vaporization is usually employed commercially for seawater desalination purposes. However, its utilization in a thermochemical hydrogen production process has not been considered previously which is really one of primary novelties of this investigation. The obtained results for the exergoeconomic and exergoenvironmental analyses of the conceptually modified cycle are also compared with those of the existing integrated cycle at the Ontario Tech University. The exergoeconomic analysis of the cycle has also been carried out for the cycle operating with and without waste heat recovery. In this regard, waste heat recovery from a steel furnace has been considered for supplying the required thermal energy for the hydrolysis step. The cost assessment of the cycle is carried out in the Aspen-plus. Compared with the existing cycle, the cycle with the proposed modification results in a lower unit cost of hydrogen. Moreover, a significant reduction in the unit cost of hydrogen is observed when waste heat recovery is considered for the modified cycle. The average unit hydrogen cost for the modified version of the cycle is evaluated to be 4.7 $/kg which reduces to 2 $/kg with incorporation of waste heat recovery. Furthermore, the overall environmental impact of the existing cycle can be potentially minimized by considering the proposed modification through flash vaporization.

Interpretation of Entropy Calculations in Energy Conversion Systems

Often, second law-based studies present merely entropy calculations without demonstrating how and whether such calculations may be beneficial. Entropy generation is commonly viewed as lost work or sometimes a source of thermodynamic losses. Recent literature reveals that minimizing the irreversibility of a heat engine may correspond to maximizing thermal efficiency subject to certain design constraints. The objective of this article is to show how entropy calculations need to be interpreted in thermal processes, specifically, where heat-to-work conversion is not a primary goal. We will study four exemplary energy conversion processes: (1) a biomass torrefaction process where torrefied solid fuel is produced by first drying and then torrefying raw feedstock, (2) a cryogenic air separation system that splits ambient air into oxygen and nitrogen while consuming electrical energy, (3) a cogeneration process whose desirable outcome is to produce both electrical and thermal energy, and (4) a thermochemical hydrogen production system. These systems are thermodynamically analyzed by applying the first and second laws. In each case, the relation between the total entropy production and the performance indicator is examined, and the conditions at which minimization of irreversibility leads to improved performance are identified. The discussion and analyses presented here are expected to provide clear guidelines on the correct application of entropy-based analyses and accurate interpretation of entropy calculations.

Computationally Accelerated Discovery and Experimental Demonstration of Gd0.5La0.5Co0.5Fe0.5O3 for Solar Thermochemical Hydrogen Production

Solar thermochemical hydrogen (STCH) production is a promising method to generate carbon neutral fuels by splitting water utilizing metal oxide materials and concentrated solar energy. The discovery of materials with enhanced water-splitting performance is critical for STCH to play a major role in the emerging renewable energy portfolio. While perovskite materials have been the focus of many recent efforts, materials screening can be time consuming due to the myriad chemical compositions possible. This can be greatly accelerated through computationally screening materials parameters including oxygen vacancy formation energy, phase stability, and electron effective mass. In this work, the perovskite Gd0.5La0.5Co0.5Fe0.5O3 (GLCF), was computationally determined to be a potential water splitter, and its activity was experimentally demonstrated. During water splitting tests with a thermal reduction temperature of 1,350°C, hydrogen yields of 101 μmol/g and 141 μmol/g were obtained at re-oxidation temperatures of 850 and 1,000°C, respectively, with increasing production observed during subsequent cycles. This is a significant improvement from similar compounds studied before (La0.6Sr0.4Co0.2Fe0.8O3 and LaFe0.75Co0.25O3) that suffer from performance degradation with subsequent cycles. Confirmed with high temperature x-ray diffraction (HT-XRD) patterns under inert and oxidizing atmosphere, the GLCF mainly maintained its phase while some decomposition to Gd2-xLaxO3 was observed.

A New Class of High Entropy Perovskite Oxides with Increased Reducibility and Stability for Solar Thermochemical Hydrogen Production

The growing demand for energy due to the increasing world population and industrialization of countries has caused pollution and climate change concerns. A global transition from fossil fuel energy to sustainable energy sources, in particular solar energy, calls for breakthroughs in energy storage and H2 fuel production. Two-step solar thermochemical hydrogen (STCH) production has emerged as an attractive route to produce clean H2 fuel from concentrated solar thermal energy. The two-step chemical looping is readily achieved using nonstoichiometric oxides such as ceria and perovskite oxides because those materials can retain their structural integrity throughout the cycling process. A new class of redox oxides, high-entropy perovskite oxides (HEPOs), are proposed to show great promises in the STCH application These novel HEPO materials have an unprecedented vast compositional space, large tunability, and unique thermodynamic and kinetic behaviors. Herein, we present that a HEPO family of La0.8Sr0.2(Mn[1-x]/3Fe[1-x]/3CoxAl[1-x]/3)O3- δ (x = 0.16, 0.2, 0.25, or 0.4) on the basis of an established STCH active material La0.6Sr0.4Mn0.6Al0.4O3- δ, was developed using high-energy ball milling (HEBM) and sintering. We comprehensively characterized the synthesized HEPOs in terms of phase purity, morphology, homogeneous elemental distribution, identification of redox active elements, reducibility extent (Δδ) and cycling structure stability and explored their STCH production performances. The optimal sample (La0.8Sr0.2(Mn0.2Fe0.2Co0.4Al0.2)O3- δ) showed a large Δδ ≥ 0.15 under the conditions of reduction at 1320 ℃ and oxidation at 870 ℃. All HEPO samples demonstrated R3-c phase stability during the cycling. Elemental mapping showed homogeneous distribution. Characterization of the electrical conductivity relaxation of the materials showed intrinsic material kinetic properties for oxygen surface exchange coefficient k ≥ 7.5 x 10-4 cm/s at 700 ℃, indicating the high kinetics for the HEPO reduction. The STCH production testing in our prototype setup showed that several promising samples had a high H2 yield of more than 300 μmol/g within less than 45 minutes upon exposure to 40 vol % steam and good cycling stability. This work opens up an avenue for the rational design of HEPOs for the solar thermochemical hydrogen production. Figure 1

Uniting Experiment and Computational Modeling to Elucidate Structure-Property Relationships of Water Splitting Materials

The layered perovskite BaCe0.25Mn0.75O3 (BCM) is a proven solar thermochemical water splitting material demonstrating higher hydrogen generation and improved redox kinetics relative to current state of the art materials. However, fundamental understanding of the underlying mechanisms of BCM’s efficacy is necessary for solar thermochemical water splitting in related perovskite-type materials to become a viable pathway for green hydrogen generation. To this end, a family of BXM (X = Ce, Nb, Pr) materials has been synthesized and undergone in-depth, multi-faceted characterization. Despite the three materials having identical structures, and differing only in 1/8 of their cation species, their water splitting performances are markedly different. X-ray absorption spectroscopy (XAS) analysis reveals substantial differences in the electronic structure of oxygen between the three samples, both when fully oxidized and at quantified degrees of reduction. However, interpreting the changes in XAS spectra of these complex materials via conventional means has proven to be challenging. The Molecular Foundry has successfully simulated the XAS spectra of the oxidized and defected structures allowing specific peaks in the XAS spectra to be correlated to molecular orbitals and providing invaluable insights into the underlying electronic changes observed experimentally. Additionally, both in situ and ex situ electron energy loss spectroscopy (EELS) analysis of the BXM materials allowed changes in the O K-edge and the Mn L-edge to be monitored with increasing extent of reduction and directly compared to XAS. The unique advantage of performing STEM-EELS analysis of these materials during in situ thermal reduction is the ability to observe underlying structural modifications, such as phase changes or defect formations, in tandem with the electronic changes in the material. Taken together, the results reported here provide a key component towards elucidating structure-property relationships for this class of solar thermochemical hydrogen production (STCH) materials.

Techno-economic analysis of a solar thermochemical cycle-based direct coal liquefaction system for low-carbon oil production

Direct coal liquefaction turns solid coal into transportable liquid fuel with a high energy conversion efficiency of nearly 60%. However, the hydrogen used in the direct coal liquefaction process mainly comes from coal gasification units, and gasification coal consumption accounts for about 30% of the total coal consumption. The authors of this article have proposed a solar thermochemical cycle-based direct coal liquefaction system and conducted a corresponding thermodynamic analysis. In this work, the economic feasibility, environmental impact, and the influence of key factors (coal price, oil price, carbon tax) for the industrial-scale low-carbon oil production system are analyzed. Compared with the traditional direct coal liquefaction system, the total coal consumption of the new system is reduced by ∼40%. Under low carbon constraints, the economics of the new system is comparable to that of the traditional one with a lower solar thermochemical hydrogen production cost (<13–16 yuan/kg H2). With the help of the solar thermochemical hydrogen production process, CO2 emissions of the new system can be reduced by 63%. Moreover, the solar thermochemical cycle could generate additional pure oxygen and profits. The methodology and results can provide important references for coal-to-liquid technology with high efficiency and low carbon emissions.