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. 2024 Oct 22;9(44):44182–44192. doi: 10.1021/acsomega.4c03487

Design and Optimization of a Chemical Looping Hydrogen Production System Using Steam Reforming for Petrochemical Plants

Mohammad Saeedan 1, Ehsan Houshfar 1,*
PMCID: PMC11541446  PMID: 39524616

Abstract

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Industrial pollution is a significant environmental concern, and researchers are seeking solutions to minimize its impact. Chemical looping combustion is an efficient technique to decrease CO2 emissions. This study delves into its application within petrochemical plants for hydrogen production. In addition to its high efficiency in hydrogen production, this method yields pure CO2 and nitrogen. The design features four reactors utilizing iron and nickel metals as oxygen carriers. A model in Aspen Plus was developed to simulate this design and evaluate its performance. Aspen Plus uses RGIBBS submodel which works based on minimization of the Gibbs free energy. The research findings indicate that this design significantly boosted the hydrogen production rate from 3380 kmol/h in conventional steam reforming reactors and 4258 kmol/h in the three-reactor chemical looping combustion setup to 4408 kmol/h. Lowering the temperatures of the iron and nickel fuel reactors, as well as the iron steam reactor, reducing the airflow rate, and increasing the pressure of the iron steam reactor all led to increased hydrogen production. Conversely, changing the pressure of the nickel fuel reactor had minimal impact. The inlet steam flow rate exhibited a nonlinear effect, initially increasing and then decreasing the hydrogen production rate.

1. Introduction

Today, hydrogen is one of the most useful and widely used substances in the chemical industry. Although this gas is abundant in the outer layers of the earth’s atmosphere, it is rarely found on its surface. Therefore, in the industry, this gas is produced using a series of chemical processes from coal and other fossil fuels that are available in larger quantities on the surface of the earth. Steam reforming is one of the most common methods used to produce hydrogen.1 Despite its advantages, this method causes the production of large amounts of CO2, which is one of the most critical greenhouse gases and has a destructive effect on the phenomenon of global warming. Therefore, researchers are trying to remove this pollutant from industries.2 One way to remove this pollutant is to use chemical looping combustion reactors.3,4 Chemical looping technology can efficiently convert captured CO2 into high-value products to help transition from fossil fuels to clean energy, emphasizing the importance of developing high-performance, low-cost metal oxides as oxygen carriers5 and highlighting the potential of chemical looping processes to enable large-scale operation for achieving energy transition and carbon neutrality.6,7 In this way, Wu et al.8 aimed to simulate and evaluate a novel Biomass Gasification-chemical looping Hydrogen Production system for sustainable green hydrogen production with high energy utilization efficiency and efficient CO2 separation capabilities, showcasing its potential for development.

The basis of these reactors is to separate oxygen from other gases that make up the air. This system consists of two air and fuel reactors and oxidized metal that flow between these reactors.9 In the air reactor, oxygen combines with the reduced metal and oxidizes it. Nitrogen and other air-forming gases also exit from the other side of the reactor. Then, the oxidized metal enters the fuel reactor, where oxygen separates from the oxygen carrier metal and combines with the fuel, producing water and CO2.10 Because exhaust gases only contain CO2 and water, and nitrogen and other gases are not present in their composition, by cooling this gas, water can be separated into liquid form, and pure CO2 can be obtained. The obtained CO2 has various applications in the industry.11

Many researchers have performed studies in the field of chemical looping combustion reactors. For example, Ishida and Jin12 presented a new plan for energy production, which consisted of chemical looping combustion and air saturation methods. In this device, a loop of chemical reactions replaced conventional combustion. The energy analysis of the model showed that the thermal efficiency of the above design was about 55.1%. Also, the above plan could be presented as a solution to solve the problem of environmental pollution by separating and recycling CO2 and using it as a side product. Also, Ishida et al.13 proposed a new oxygen carrier metal for chemical looping combustion. Two kinds of methods, the sol–gel method and dissolution method were investigated to prepare NiO mixed with zirconium metal from the viewpoint of chemical kinetics and mechanical strength of the material. The effect of reaction temperature, particle size, and gas composition were analyzed experimentally and the experimental results related to chemical kinetics were interpreted by an unreacted core shrinking model. The particles that were produced using the dissolution method were a good candidate for the chemical looping combustion method. The following results were obtained for these particles: The reaction temperature, particle size, and gas composition strongly affect the overall reaction rate of the reactants.

Anheden and Svedberg14 investigated the performance of a chemical looping combustion device coupled with a solid fuel to gas converter device and compared it with conventional combustion devices. The oxygen carrier metals used in this research were nickel, iron, and manganese. This research demonstrated that the system introduced in this research had a similar efficiency to conventional combustion systems. In contrast, this system can separate CO2 from gases. In 1998, Jin et al.15 introduced a new alloy as an oxygen carrier metal in the chemical looping combustion system. In this research, the basic properties of metals in both steps of reduction and oxidation were investigated using a thermogravimetric reactor device. The results obtained from this research showed that this alloy can be a suitable option for use in chemical looping combustion reactors. Adánez et al.16 investigated the properties of oxygen carrier metals experimentally. they prepared about 240 samples of oxygen carrier metal using copper, iron, manganese, and nickel, based on aluminum oxide, sepiolite, silicon oxide, titanium oxide, and zirconium oxide. These metals were made at four temperatures between 950 and 1300 °C. The effect of the chemical nature and composition of the carrier, the sintering temperature, etc. was investigated by the reactivity test in the thermogravimetric analyzer using Methane as fuel. According to the results of the research, the best oxygen carriers made of copper were metals based on silicon oxide and titanium oxide which were made at a temperature of 950 °C. Among the oxygen carriers made of iron, metals based on aluminum oxide and zirconium oxide showed the best performance. Also, zirconium oxide and titanium oxide formed the best base for manganese and nickel metals.

Adánez et al.17 continued their research and designed and investigated a 10 kW device, which consisted of two interconnected reactors and worked based on chemical looping combustion. The effect of operating conditions such as the ratio of oxygen carrier metal to fuel, gaseous fuel velocity, size of oxygen carrier metal, and fuel reactor temperature on fuel conversion ratio was investigated. The oxygen carrier metal used was an alloy of copper oxide and aluminum oxide, which was prepared by dry impregnation. Also, the attrition, agglomeration, and reactivity of oxygen carrier metals were analyzed. According to the results of the research, the ratio of oxygen carrier metal to fuel was the most important factor affecting the methane conversion rate.

Saeidi et al.18 investigated the application of the chemical looping combustion method in the refining of heavy gasoline and analyzed this device using a mathematical model. The metal used in this device was an alloy of nickel oxide and aluminum oxide. This research showed that using the chemical looping combustion device in this system increased the hydrogen production rate. Chen et al.19 presented a new design combining the chemical looping combustion method and a supercritical CO2 (sCO2) Brayton cycle. an extensive analysis was conducted based on the first law of thermodynamics to evaluate the performance of this system. The power efficiency of about 41.3% and the heat efficiency of about 40.4% were obtained for the basic design. Also, the device’s overall efficiency was calculated to be about 81.7%, including the compression of CO2 up to the pressure of 120 bar. Du et al.20 proposed a direct CLC-driven combined supercritical CO2 and air Brayton cycle with near-zero carbon emissions and compares its thermoeconomic performance with and without preheating through optimization, showcasing significant net power and efficiency gains as well as enhanced thermoeconomic performance through preheating.

In the domain of experimental research on oxygen carrier metals, numerous investigators have undertaken comprehensive studies. For instance, Son and Kim21 selected nickel oxide and iron oxide (NiO, Fe2O3) as the oxygen carrier metals, and bentonite and aluminum oxide (TiO2, and Al2O3) as the supports for the chemical looping combustion method. The reactivity of oxygen carrier particles in the thermobalance reactor was determined under reducing and oxidizing conditions at temperatures ranging from 923 to 1223 K. Nickel oxide exhibited higher reactivity compared to iron oxide, and particles supported by bentonite or aluminum oxide showed greater reactivity than titanium oxide. Particle reactivity increased with rising temperature and the amount of nickel oxide. Monazam et al.22 performed a thermogravimetric analysis (TGA) of the reduction of hematite in a continuous stream of methane (15, 20, and 35%) in the temperature range between 700 and 825 °C during ten reduction cycles. Mass spectroscopy analysis of the product gas showed the presence of CO and H2O in the early stages of the reaction, and H2 and CO in the final stages. It was observed that the reaction rate increases for both reactions based on temperature and methane concentration in the inlet gas.

Ma et al.23 doped Fe2O3/Al2O3 (FA) with different metals such as Sr, La, and Ce to enhance the redox performance during cyclic reactions. The influence of various dopants on FA’s redox performance was investigated through experimental results and characterization analysis. The order of effectiveness in promoting redox performance among dopants was observed to be Sr > La > Ce. Deactivation of Ce-FA and La-FA occurred within 20 cycles. Characterization results indicated that the addition of Sr effectively increased the concentration of oxygen vacancies, inhibiting FA phase segregation. Recently, Dou et al.24 prepared oxygen carrier materials MCM-41 and SBA-15 based on nickel with and without CeO2 promoter using direct synthesis and impregnation methods. Various techniques such as Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma atomic emission spectroscopy (ICP-AES), hydrogen temperature-programmed reduction (H2-TPR), and differential scanning calorimetry (DSC)-TGA were employed to study these oxygen carrier materials. The mesoporous oxygen carrier metal exhibited a high specific surface area, large pore volume, and uniform pore size. The hydrogen purity achieved using CeNiO/SBA-15 was greater than 90%. Increasing the percentage of nickel oxide and CeO2 on the oxygen carrier metal SBA-15 enhanced oxygen transport and provided exceptional looping stability.

Dou et al.25 investigated the chemical looping steam reforming method with the assistance of glycerol, which is enhanced by the absorption of CO2. The method involves the use of oxidized metal NiO/NiAl2O4 as a steam reforming catalyst, reduced metal NiO/NiAl2O4 as a CO2–CH4 dry reforming catalyst, and inexpensive dolomite as a CO2 absorber. The research results indicated that hydrogen with a purity of 92.5% is produced in one step, and the production of CO2 was decreased to zero. The reduced NiO/NiAl2O4 catalyst dried CO2 and CH4 well at 850 °C, producing syngas with a molar ratio of H2 to CO of 0.8 to 1.1 through the conversion of CO absorbed by dolomite. NiAl2O4 with 15 wt % NiO achieved the highest hydrogen and syngas production rate and demonstrated the best performance for the system described above. The catalyst and dolomite exhibited good stability without any loss of activity over 10 cycles.

One of the crucial applications of the chemical looping combustion method is to employ this method in hydrogen production. Many researchers have focused on this field, including Rydén and Lyngfelt26 who proposed a new plan for hydrogen production based on the chemical looping combustion method. In this research, hydrogen was produced by the steam reforming method, and the thermal energy required for hydrogen production was obtained by the chemical looping combustion method. In addition to separating CO2, this model had a higher ability to produce hydrogen than the old and common methods. Gamwo et al.27 investigated the application of the chemical looping combustion method using manganese metal as an oxygen carrier metal in this system for hydrogen production. They showed that in this system, the methane conversion rate and the amount of hydrogen production reached 73.46% and 4562 mol/h, respectively. Also, increasing the temperature of the fuel reactor from 720 to 880 K raised the methane conversion rate by about 13.39%.

Furthermore, Rahimpour et al.28 presented a new plan for hydrogen production, where the thermal energy required for it was provided by the chemical looping combustion method. They indicated that the chemical looping combustion reactor increased the rate of methane conversion and hydrogen production. Recent studies indicate that simulation can be a potent tool for evaluating the potential and effectiveness of chemical looping combustion in practical applications. Abbasi et al.29 designed a chemical looping combustion reactor to replace an old hydrogen production reactor. Their oxygen carrier metal was an alloy of nickel oxide and γ aluminum oxide. The simulation results showed that methane conversion and hydrogen production rates increased by 7.54 and 25.48% compared to the previous reactor. Also, with a rise in the flow rate from 90 mol/s to 180 mol/s, the conversion rate of methane and hydrogen production reached 16.73 and 40%.

Further, Abbasi et al.30 continued their research and investigated hydrogen production from methane based on the chemical looping combustion method. In this research, the chemical looping combustion device provided the necessary thermal energy for hydrogen production using manganese oxygen carrier metal. This research showed that the methane conversion rate and hydrogen production rate reached 73.46% and 4562 kmol/h, respectively. Also, by increasing the fuel reactor temperature to 880 K, the methane conversion and hydrogen production rate reached 81.15% and 4790 kmol/h, respectively. The production of hydrogen using the chemical looping combustion method was also studied by Karimi et al.31 This research investigated a system of oxygen carriers made of four metals: iron, manganese, cobalt, and copper. Also, inert materials Al2O3 and TiO2 were used as support. The optimum temperature for maximum conversion of methane for iron, manganese, cobalt, and copper was 1025, 1030, 900, and 800 °C, respectively. Also, this research demonstrated that the methane conversion rate for iron alloy and aluminum oxide was about 95–100%, and for iron alloy and titanium oxide, it was about 78–80%.

Aside from the chemical looping combustion method in hydrogen production, this method has been used in hybrid systems to produce hydrogen and electric energy simultaneously. In this field, many researchers have concentrated on this subject. Wolf and Yan32 presented a new design based on the chemical looping combustion method, which could simultaneously produce thermal energy, electricity, and hydrogen. They investigated the effects of the functional parameters of the device, such as the temperature of different points and the flow rate of particles on the hydrogen efficiency, power, etc. The proposed process had the potential to achieve a thermal efficiency of 54% while capturing 96% of the CO2 and compressing it to 110 bar.

Zafar et al.33 proposed a plan to simultaneously produce hydrogen and power from natural gas using a chemical looping combustion reactor. The oxygen carrier metals used in this research were nickel, copper, manganese, and iron. When nickel oxide was used in the chemical looping combustion reactor, the highest amount of hydrogen was observed at the output of the fuel reactor. Therefore, nickel oxide seemed to be this system’s best oxygen carrier metal. Zhang et al.34 presented a plan for a hybrid system including a solid fuel to gas converter and a chemical looping combustion device for solid fuel combustion. The results of this research indicated that the hydrogen efficiency of 49.5% for this device in the ratio of steam and hydrogen to carbon equal to 2 and the operating temperature of 1100 K could be achieved, which was about 80% higher than conventional combustion devices that absorb and separate CO2. Chen et al.35 combined a fuel cell and a gas turbine with a chemical looping hydrogen generator and simulated the hybrid system with Aspen Plus. They reported that the higher pressure and temperature of the system increase the efficiency of the system. Also, a higher fuel conversion rate leads to a higher fuel cell efficiency. Ozcan and Dincer36 presented a hybrid model of fuel cells and gas turbines based on the chemical looping combustion method, capable of producing hydrogen and separating CO2. The hydrogen efficiency of the device at a pressure of 20 bar and a temperature of 900 °C was about 43.53%.

Sorgenfrei and Tsatsaronis37 proposed a plan including two chemical looping combustion reactors to produce hydrogen and electricity and separate CO2 simultaneously. According to the simulation results, when auxiliary combustion was not used, the efficiency of power production was 14.12% and the hydrogen efficiency was 33.61%. When they used auxiliary combustion, the power production efficiency reached 27.47%, the hydrogen efficiency reached 39.23%, and the CO2 output attained 356.36 g/kWh. Edrisi et al.38 proposed a plan to simultaneously produce nitrogen, hydrogen, and pure CO2 based on the chemical looping combustion method. The proposed project had a return rate of about 28%, while this rate for the old standard plans was about 20%. Aziz et al.39 proposed a method to convert brown coal into hydrogen and power. This system consisted of a coal dryer, a chemical looping combustion system with coal fuel, and a hydrogen production device. The proposed plan had a hydrogen efficiency of 71.4% and a power production efficiency of 19.9%. Mehrpooya et al.40 presented a new plan for a hybrid system that included a biomass vaporizer, a chemical looping combustion reactor, a fuel cell, and a steam turbine. In the chemical looping combustion reactor, calcium oxide was used as an oxygen carrier metal. The products of this device included hydrogen with high concentration and electrical energy. The total efficiency of this device reached approximately 55.8%, and all the produced CO2 was also absorbed.

In this article, to improve the hydrogen production process in petrochemical plants and reduce its produced pollution, rather than using the conventional steam reforming reactor, a four-reactor chemical looping combustion system is designed. This system consists of two fuel reactors, one air reactor, and one steam reactor, and nickel and iron are used as oxygen carrier metals in this system. Using this system prevents direct contact of air with fuel. The air reacts with the oxygen-carrier metal in the first step, and oxygen is combined with the metal and separated from the nitrogen. The oxidized metal reacts with the fuel in the next step and the reduced metal, water, and CO2 are produced. As a result, by cooling the exhaust gas, water can be separated from it and CO2 can be obtained in a pure form, and in addition to not polluting the environment, CO2 can also be used in industry. Therefore, using this method, in addition to greater efficiency and no pollution, with the production of nitrogen gas and CO2 in pure form, also causes more economic justification for the use of this method. A one-dimensional model in Aspen Plus simulates the proposed design. Thanks to this model, the effect of various parameters on hydrogen production has been investigated for this system. Finally, the optimal mode for the system’s performance has been obtained.

2. System Description

Figure 1 depicts an overview of the model generated by Aspen Plus, while Table 1 presents the properties of the system’s streams. As can be seen, this system consists of the iron fuel reactor, iron steam reactor, nickel fuel reactor, and nickel air reactor. This system consists of two sections: iron (including iron-fuel and iron-steam reactors) and nickel (including nickel-fuel and nickel-air reactors). The final task of the iron part is to produce hydrogen gas from steam. But all the reactions that happened in these two reactors are very endothermic and therefore, to provide this thermal energy, some of the fuel is used in the iron section to reduce the iron oxide and the rest goes to the nickel section. No specific product is produced in the nickel section, but the reactions that happen in this section are exothermic and produce the necessary thermal energy for the iron section. The temperature of the nickel section must be higher than the iron section so that thermal energy can flow easily. Also, due to the necessity of reactivity at the specified temperatures for the reactors, nickel metal was chosen for the nickel section, and iron metal was chosen for the iron section.

Figure 1.

Figure 1

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A view of the proposed model.

Table 1. Properties of the System’s Streams.

  AIR-IN AIR-OUT EXIT-1 F3-R4 FE3O4-IN FE3O4OUT FEO-OUT FUEL H2-OUT NIO-IN NIO-OUT R1-F1 R2-F2 R3-F3 R4-F4 UN-BURN1 STEAM
temperature (°C) 540 900 1050 1050 415 815 715 600 815 900 900 715 415 850 500 715 540
pressure (bar) 1 1 10 10 1 1 1 40 1 1 1 1 180 60 20 1 1
mole flow (kmol/h) 24000 20106 15064 15014 3500 3501 5706 9129.6 8000 15000 15002 20766 11501 30079 35108 15060 8000
H2O   12.2 11794.2 12.2     0.7 5318.9 3591.8     5213.7 3592.2 11806.4 12.2 5213.0 8000.0
Fe3O4         3499.7 3499.5 2397.1         2397.1 3499.5        
Fe         0.4 0.9 3307.4         3307.4 0.9        
H2           0.1 0.2 537.7 4408.2     6575.0 4408.3 0.0   6574.8  
O2 5040.0 1133.3                 0.1       1133.4    
N2 18960.0 18957.9 138.6         138.8     2.3 138.8   138.8 18960.2 138.8  
CH4               2975.3 0.2     9.3 0.2     9.3  
CO2   2.3 3131.7 2.3       157.0       1705.8   3134.0 2.3 1705.7  
FeO             0.5         0.5          
CO             0.1 1.8       1419.1       1419.0  
NiO       68.9           8100.0 7882.1     68.9 7882.1    
Ni       14931.1           6900.0 7117.9     14931.1 7117.9    
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Another critical consideration pertains to the propensity of nickel to agglomerate at temperatures exceeding 900 °C. This phenomenon results in a reduction of the effective surface area of the oxygen carrier, thereby impeding its reactivity and necessitating more frequent replacement cycles. Although the chemical looping concept remains valid at elevated temperatures, the system’s overall performance and economic viability are significantly impacted by oxygen carrier degradation. To address this challenge, further research should explore strategies for mitigating nickel agglomeration.

In a chemical looping hydrogen production system, specific components serve as reactants and are consumed during the process (e.g., steam for reforming, fuel for the reduction step). These components are separated from the product stream and are not reintroduced into the system. However, the oxygen carrier exiting the fuel reactor (in its reduced state) is a valuable material that should be reused multiple times. Consequently, it is recycled back to the air reactor inlet, ensuring continuous operation of the chemical looping process, with the metal oxide acting as a reusable oxygen transport medium.

There are many compounds for nickel and especially for iron. To select a suitable set of the above metal combinations, all the above metal combinations were selected in Aspen Plus, and after running the software, the output of the system, was considered as the new input of the system. and the software was run again. After repeating this cycle several times, the output of the software was equal to its input, and that set was considered as the input of the system. The 4 separated reactors of this system are explained below.

2.1. Iron Fuel Reactor

This reactor is considered as the input of the system. Fuel and oxidized iron enter this reactor. As a result of the reaction between the fuel and oxidized iron, oxygen is separated from the metal. It reacts with the fuel, turning some of the fuel into combustion products such as water and CO2. During this process, the metal is also reduced by separating oxygen. steam, CO2, and unreacted fuel enter the nickel fuel reactor, and finally, reduced iron enters the iron steam reactor.

2.2. Iron Steam Reactor

In this reactor, reduced iron from one side and steam from the other enter the iron steam reactor, and during the reaction between reduced iron and steam, oxidized iron and hydrogen are produced.21 This reaction is highly endothermic and must supply its thermal energy from the nickel air reactor. The oxidized iron is re-entered into the iron fuel reactor, and the cycle repeats.

2.3. Nickel Fuel Reactor

The unreacted fuel from the iron fuel reactor enters the nickel fuel reactor. Nickel oxide also enters this reactor, and while reacting with fuel, loses its oxygen and turns into nickel. The separated oxygen reacts with the fuel and produces water and CO2. The combustion products from this reactor have a very high temperature, and their thermal energy is used to heat the materials entering the other reactors.

2.4. Nickel Air Reactor

In this reactor, air flows into the reactor and reacts with nickel. The output of this reactor is oxidized nickel and high-temperature oxygen-free air. The oxidized nickel enters the nickel fuel reactor again, and the cycle repeats. The reaction in this reactor is highly exothermic and provides the necessary thermal energy to carry out the reaction in other reactors.

3. The Method of Performance Evaluation

In this research, Aspen Plus was used to simulate the system. The system that the chemical looping combustion reactors will replace is the hydrogen production reactor using the conventional method of steam reforming used in the Zagros Petrochemical Company. The inlet fuel is syngas and its temperature, pressure, and flow rate are considered 793 K, 40 bar, and 9129.6 kmol/h, respectively. The properties of the inlet fuel are given in Table 2.

Table 2. Properties of the Inlet Fuel28 a.

inlet temperature (K) 793
inlet pressure (bar) 40
inlet fuel flow rate (kmol/h) 9129.6
Composition of the Inlet Fuel
CO2 (%) 1.72
CO (%) 0.02
H2 (%) 5.89
CH4 (%) 32.59
N2 (%) 1.52
H2O (%) 58.26
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a

Reproduced from Ref (28). Copyright 2013 American Chemical Society.

Fuel with the specified properties is entered into the model. The parameters used in this study to investigate the system’s performance are hydrogen efficiency and total efficiency, which are described in the following equations:

3. 1
3. 2
3. 3

where in the above equations ηnet is plant net power efficiency (%), Wnet is the net power of the coproduction plant (kW), ṁfuel is the fuel mass flow (kg/s), LHVfuel is the fuel lower heating value (kJ/kg), ηH2 is hydrogen production efficiency (%), LHVH2 is hydrogen lower heating value (kJ/kg), ṁH2 is hydrogen mass flow (kg/s), and ηE is the total efficiency.41

Also, in this research, the proposed model has been analyzed from the viewpoint of exergy, as a powerful energy analysis tool42 Exergoeconomic analysis was conducted to evaluate an oxy-fuel power plant with chemical looping combustion.43 Exergy is the highest level of work a system can produce before reaching the dead state. This state is where the system has reached the temperature and pressure of the environment and cannot produce work. The total exergy of chemical flows consists of two parts, physical and chemical, which can be seen in eq 4:44

3. 4

In this equation, Xph is the physical exergy and Xch is the chemical exergy of the flow. The physical and chemical exergies of the flow are defined by eqs 5 and 6:45

3. 5
3. 6

In the above equations, X0i is the standard chemical exergy of the i-th component at ambient temperature and pressure, and xi is the mole fraction of the i-th component.

Also, the exergy of thermal energy is calculated as follows:

3. 7

In eq 7, XQ is the exergy of the entered thermal energy, Q is the thermal energy input to the system, T0 is the temperature of the environment, and TQ is the temperature at which the thermal energy enters the system.

By knowing the exergy of flow and thermal energy, the exergy efficiency of the system can be obtained as follows:

3. 8
3. 9
3. 10

While it is well-established that employing chemical kinetics or Computational Fluid Dynamics (CFD) models yields rigorous analyses, simulating a complex system with multiple reactors using detailed chemical kinetics or CFD models can be computationally expensive and time-consuming. In contrast, Aspen Plus models based on Gibbs free energy have demonstrated high accuracy for fixed-bed reactors and processes involving syngas fuels.46 In our proposed system, we leverage both approaches. Furthermore, our Aspen Plus model exhibits excellent agreement with experimental data, with simulation results deviating by less than 2% from real-world observations.

For this research, we utilize the RGIBBS submodel to simulate reactors. This submodel handles single-phase chemical equilibrium or simultaneous phase and chemical equilibrium. To employ this submodel effectively, knowledge of the temperature and pressure of the reactors, or the pressure and enthalpy of the reactor, is essential. Notably, the RGIBBS submodel minimizes Gibbs free energy based on atomic equilibrium constraints, obviating the need for explicit reaction stoichiometry.46

4. Results and Discussion

4.1. Validation of the Model

To ensure the proper performance of the prepared model, this model has been validated with the experimental data obtained from Zagros Asaluyeh Petrochemical Company.28 For this purpose, the conventional methane reformer reactor of this petrochemical company was simulated and validated with the experimental data. Table 3a shows the percentage of output products obtained from this model (CLC) compared to experimental data (CSR).

Table 3. (a) Validation of the Model Output with Experimental Data, (b) Comparing the Performance of the Proposed Design with Other Reactors, (c) Exergy Efficiency of the System.

(a) validation
 (b) comparison
 (c) performance
  CLC (current work) (%) CSR (experimental data) (%) ERROR (%) hydrogen producer system hydrogen production rate (kmol/h) hydrogen efficiency (%) reactor name exergy efficiency (%)
H2 31.37 31.53 0.5 proposed system 4875 49.75 iron steam reactor 93.34
N2 1.3 1.3 0.35 common method 3380 34.5 nickel air reactor 53.48
CH4 20.43 20.33 0.47 3-reactor CLC with nickel metal 4258 43.45 iron fuel reactor 52.18
CO2 5.72 5.72 0.02 3-reactor CLC with iron metal 4300 43.88 nickel fuel reactor 38.39
CO 3.13 3.19 1.99       system 34.25
H2O 38.06 37.94 0.31          
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As can be seen in Table 3, the results obtained from the model were in good agreement with the experimental data and the maximum observed error is less than 2%, which shows the high accuracy of this model.

4.2. System Performance

One of the advantages of chemical looping combustion reactors is the separation of CO2 pollutants. In addition, these reactors have relatively good performance compared to conventional steam reforming reactors.28Table 3 shows the performance of the chemical looping combustion reactor compared to conventional reactors and the three-reactor chemical looping combustion device designed by Abbasi et al.47

Table 3 shows that the proposed design performs better than the three reactors’ chemical looping combustion device and the conventional hydrogen production device.

4.3. Exergy Analysis

This section focused on the exergy analysis of the system. Table 3c shows the exergy efficiency of different reactors of the system and the overall exergy efficiency of the system.

As it is clear from Table 3, the lowest exergy loss and the highest exergy efficiency are related to the iron steam reactor with an efficiency of 93.34%, and the highest exergy loss and the lowest exergy efficiency are related to the nickel fuel reactor with an exergy efficiency of 38.39%. Also, the iron fuel reactor, with an efficiency of 52.18%, and the nickel air reactor, with an efficiency of 53.48%, have almost the same exergy efficiency; thus, they are placed between the nickel fuel reactor and the iron steam reactor. Also, since the transfer of thermal energy between different reactors of the system results in exergy loss, the overall exergy efficiency of the system is lower than the efficiency of each reactor and is equal to 34.25%.

4.4. Sensitivity Analysis

Sensitivity analysis has been used to optimize the performance of the system. In this step, the effect of different parameters on the performance of the system and hydrogen production rate was investigated, and the optimal value of that parameter was obtained for the model. After optimization of several parameters, the amount of the produced hydrogen was increased. In the following, the influence of the effective parameters on the system’s performance has been investigated.

Figure 2a shows the changes in hydrogen and total efficiency in terms of temperature changes in the iron fuel reactor. As can be seen, hydrogen production efficiency increases as the temperature decreases. This trend is because the reaction in the iron fuel reactor is endothermic, when the reaction temperature decreases, less thermal energy is needed to carry out the reaction. Therefore, more thermal energy from fuel combustion is spent on the production of hydrogen gas from water, and the hydrogen efficiency increases.

Figure 2.

Figure 2

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Hydrogen and total efficiency versus (a): iron fuel reactor temperature and (b): pressure of the nickel air reactor.

Figure 2b shows the changes in hydrogen and total efficiency according to changes in the pressure of the nickel air reactor. As can be seen, the hydrogen efficiency does not change significantly with changes in the pressure of the nickel air reactor, and the changes in this factor do not significantly affect the system’s performance.

However, as the increment in reactor pressure increases the cost of building the body of the reactor, in this research, the pressure of 30 bar is considered for the nickel air reactor.

Figure 3a shows the changes in hydrogen and total efficiency according to changes in the temperature of the nickel fuel reactor. The hydrogen efficiency drops with increasing temperature. The reason behind this problem is that the reaction in this reactor is exothermic, and with an increase in the temperature of the nickel fuel reactor, the reaction goes toward the reactants and the reaction rate, and thus the produced thermal energy decreases. Therefore, the thermal energy required to produce hydrogen gas in the iron-steam reactor is reduced and the amount of hydrogen production is also reduced.

Figure 3.

Figure 3

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Hydrogen and total efficiency versus (a): nickel fuel reactor temperature and (b): steam flow rate.

Figure 3b shows the changes in hydrogen and total efficiency based on the changes in the steam flow rate. Figure 3b indicates that hydrogen efficiency does not have a uniform trend with an increasing steam flow rate. Although the rate of its changes is low, at first, the rate of hydrogen production increases with a rise in the steam flow rate, and then it decreases with the increase of this rate again. This process arises from the fact that by increasing the steam flow rate, on the one hand, the possibility of the reaction between steam and metal increases, and as a result, the likelihood of hydrogen production increases. On the other hand, water is a substance with a high heat capacity, and a lot of energy is required to increase its temperature. Therefore, the increase in steam flow causes more energy to be spent raising the water temperature, so the remaining energy for the reaction of water with iron diminishes. Therefore, with the increase in the steam flow rate, initially, the first factor has a more significant effect and increases the hydrogen production rate. Then, gradually, the role of the first factor becomes weaker, and the role of the second factor becomes more vital. Consequently, the hydrogen production rate decreases with the increase in the steam flow rate.

Figure 4a shows the changes in hydrogen and total efficiency according to the changes in air flow rate. It illustrates that hydrogen efficiency decreases with an increase in the airflow rate. This trend is because, with a rise in the airflow, the reaction between nickel metal and air increases, and more nickel metal is oxidized. The rise in nickel oxide production causes more fuel to react with nickel oxide in the nickel fuel reactor. As a result, the remaining fuel for the iron fuel reactor will decrease. reducing the fuel for this part allows less iron to be reduced in contact with this fuel. Thus, the iron in the iron steam reactor for reaction with steam is reduced, and less hydrogen is produced.

Figure 4.

Figure 4

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Hydrogen and total efficiency versus (a): air flow rate and (b): iron steam reactor temperature.

Figure 4b shows the changes in hydrogen and total efficiency according to the changes in the temperature of the iron steam reactor. As can be seen, as the temperature of the iron steam reactor rises, the hydrogen efficiency decreases. This tendency is because as the temperature of the iron steam reactor increases, the temperature of the steam and hydrogen output from the reactor increases. Due to the high heat capacity of water, more energy is spent on increasing the temperature of the water. As a result, the remaining energy to provide thermal energy for the reaction of iron with steam is reduced, and therefore less hydrogen is produced.

Figure 5a shows the hydrogen and total efficiency changes versus nickel air reactor temperature changes. As can be seen, a rise in the temperature of the nickel air reactor causes the hydrogen efficiency to decrease. This trend is because the reaction that took place in the mentioned reactor is exothermic. With the increase in this reactor’s temperature, the above reaction moves toward the reactants, and less metal is oxidized. decreasing the oxidation rate of nickel causes a decrease in the produced thermal energy. Reducing the thermal energy produced in the nickel air reactor decreases the thermal energy required to produce hydrogen from steam, and as a result, the amount of produced hydrogen decreases.

Figure 5.

Figure 5

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Hydrogen and total efficiency versus (a): nickel air reactor temperature and (b): iron fuel reactor pressure.

Figure 5b shows the changes in hydrogen and total efficiency in terms of changes in the pressure of the iron fuel reactor. As can be seen, an increase in the pressure of the iron fuel reactor leads to a decrease in hydrogen efficiency. For justification of this phenomenon, eq 11 should be carefully considered:

4.4. 11

As it is clear from eq 11, there is 1 mol of gaseous substances in the reactants and 3 mol of gaseous substances in the products. As a result, increasing the pressure of this reactor leads the reaction in a direction where the number of moles of gaseous substances decreases, which reduces the pressure. Therefore, when the pressure of this reactor rises, the reaction moves toward the reactants, and the amount of reduced iron decreases. As a result, the amount of steam reacting with iron decreases, and ultimately the rate of hydrogen production decreases.

Figure 6a shows the changes in hydrogen and total efficiency according to changes in the iron steam reactor pressure. As can be seen, hydrogen efficiency increases with the increase in the pressure of the iron steam reactor. The reason for this event is that with a rise in the pressure of the iron steam reactor, the possibility of a reaction between steam and reduced metal increases, and as a result, the rate of hydrogen production increases.

Figure 6.

Figure 6

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Hydrogen and total efficiency versus pressure of (a) iron steam reactor and (b) nickel fuel reactor.

Figure 6b shows the changes in hydrogen and total efficiency according to the changes in the pressure of the nickel fuel reactor. As can be seen, the hydrogen efficiency does not change significantly with changes in the pressure of the nickel fuel reactor, and the changes in this factor do not significantly impact the system’s performance. However, as the increment in reactor pressure increases the cost of building the body of the reactor, in this research, the pressure of 20 bar is considered for the nickel fuel, and the pressure of 50 bar is considered for the iron steam reactor.

As it is clear in all the above figures, the total efficiency has a similar trend with the hydrogen efficiency and its value is slightly higher than the hydrogen efficiency. The reason for this is that in the above system, the most focus is on hydrogen production, and for this reason, it has been tried to use the thermal energy of the output gases to heat the system input, and for this reason, the outgoing gases have a low temperature, and this causes the output power of the mentioned system to be minimal. Finally, Table 4 presents an overview of the results obtained in this research.

Table 4. Effect of the Functional Parameters on the Hydrogen Efficiency.

  involved parameter hydrogen efficiency
Fe-FR_Pr (bar) 1 28.41
20 23.87
Fe-SR_Pr (bar) 40 28.41
180 34.34
Fe-SR_Temp (°C) 415 37.43
815 34.34
Ni-AR_Temp (°C) 500 45.97
900 37.43
Water_Flow (kmol/h) 4000 27.93
8000 28.41
10 000 26.66
Air_Flow (kmol/h) 24 000 32.53
44 000 27.8
Ni-FR_Pr (bar) 20 49.75
60 49.75
Ni-AR_Pr (bar) 20 46.8
70 45.83
Ni-FR_Temp (°C) 850 48.95
1100 39.22
Fe-FR_Temp (°C) 715 49.75
915 44.85
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5. Conclusions

This research introduces a novel system based on the chemical looping combustion method for CO2-free hydrogen production in petrochemical plants. The system comprises four key components: the iron fuel reactor, iron steam reactor, nickel fuel reactor, and nickel air reactor, utilizing nickel and iron as oxygen carriers. The iron part (including the iron-fuel and iron-steam reactors) is responsible for producing hydrogen gas from steam, while the nickel part (including the nickel-fuel and nickel-air reactors) supplies the necessary thermal energy for the reactions occurring in the iron section.

The proposed design underwent rigorous simulation using Aspen Plus software, enabling detailed analysis and optimization. Within this software, the RGIBBS submodel was employed to simulate the reactors. Notably, the RGIBBS submodel minimizes Gibbs free energy based on atomic equilibrium constraints, eliminating the need for explicit reaction stoichiometry.

The study’s findings underscore the critical role of optimizing various parameters, including reactor temperatures, pressures, steam flow rates, and airflow rates, in achieving high hydrogen efficiency. Lowering the temperatures of the iron and nickel fuel reactors, adjusting the nickel air reactor pressure and temperature, enhancing the air flow rate, and increasing the iron steam reactor pressure all contribute to improved efficiency. Interestingly, the relationship between steam flow rate and efficiency is nonlinear, with an initial increase in efficiency observed when raising the steam flow rate from 4000 to 8000 kmol/h, followed by a decrease at 10 000 kmol/h.

Furthermore, the investigation explored the impact of varying the pressure of the nickel fuel reactor, yielding consistent results. The proposed system not only offers a promising alternative to traditional hydrogen production methods but also demonstrates superior efficiency compared to three-reactor chemical looping combustion systems. Beyond its CO2 emissions reduction potential, the design’s high hydrogen efficiency positions it favorably against conventional approaches.

In summary, this innovative system not only contributes to environmental sustainability by eliminating CO2 emissions but also represents a significant advancement in efficient hydrogen production. Further research and development in this direction hold great promise for sustainable hydrogen technologies.

The authors declare no competing financial interest.

References

  1. Patcharavorachot Y.; Wasuleewan M.; Assabumrungrat S.; Arpornwichanop A. Analysis of hydrogen production from methane autothermal reformer with a dual catalyst-bed configuration. Theor. Found. Chem. Eng. 2012, 46 (6), 658–665. 10.1134/S0040579512060188. [DOI] [Google Scholar]
  2. Birol F. Energy economics: a place for energy poverty in the agenda?. Energy J. 2007, 28 (3), iv-6. 10.5547/issn0195-6574-ej-vol28-no3-1. [DOI] [Google Scholar]
  3. Moghtaderi B. Review of the recent chemical looping process developments for novel energy and fuel applications. Energy Fuels 2012, 26 (1), 15–40. 10.1021/ef201303d. [DOI] [Google Scholar]
  4. Oh D.-H.; Lee C.-H.; Lee J.-C. Performance and Cost Analysis of Natural Gas Combined Cycle Plants with Chemical Looping Combustion. ACS Omega 2021, 6 (32), 21043–21058. 10.1021/acsomega.1c02695. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Qasim M.; Ayoub M.; Aqsha A.; Ghazali N. A.; Ullah S.; Ando Y.; Farrukh S. Investigation on the Redox Properties of a Novel Cu-Based Pr-Modified Oxygen Carrier for Chemical Looping Combustion. ACS Omega 2022, 7 (45), 40789–40798. 10.1021/acsomega.2c02993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Wang F.; Chen S.; Duan L.; Xiang W. Carbon Dioxide Capture and Hydrogen Production with a Chemical Looping Concept: A Review on Oxygen Carrier and Reactor. Energy Fuels 2023, 37 (21), 16245–16266. 10.1021/acs.energyfuels.3c02889. [DOI] [Google Scholar]
  7. Zhu X.; Wang R.; Shen T.; Shen L. Simulation and Optimization of a Multistage Interconnected Fluidized Bed Reactor for Coal Chemical Looping Combustion. ACS Omega 2022, 7 (45), 40990–41000. 10.1021/acsomega.2c04192. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Wu D.; Gao Z.; Wu S.; Xiao R. Comparative Analysis of Energy and CO2 Emission for the Integration of Biomass Gasification with a Dual-Reactor Chemical Looping Hydrogen Production Process. Energy Fuels 2023, 37 (18), 14033–14045. 10.1021/acs.energyfuels.3c02405. [DOI] [Google Scholar]
  9. Hossain M. M.; de Lasa H. I. Chemical-looping combustion (CLC) for inherent CO2 separations—a review. Chem. Eng. Sci. 2008, 63 (18), 4433–4451. 10.1016/j.ces.2008.05.028. [DOI] [Google Scholar]
  10. Adanez J.; Abad A.; García Labiano F.; Gayán P.; de Diego L. F. Progress in chemical-looping combustion and reforming technologies. Prog. Energy Combust. 2012, 38 (2), 215–282. 10.1016/j.pecs.2011.09.001. [DOI] [Google Scholar]
  11. Brahimi D.; Choi J.-H.; Youn P. S.; Jeon Y.-W.; Kim S. D.; Ryu H.-J. Simulation on operating conditions of chemical looping combustion of methane in a continuous bubbling fluidized-bed process. Energy Fuels 2012, 26 (2), 1441–1448. 10.1021/ef2015233. [DOI] [Google Scholar]
  12. Ishida M.; Jin H. A new advanced power-generation system using chemical-looping combustion. Energy 1994, 19 (4), 415–422. 10.1016/0360-5442(94)90120-1. [DOI] [Google Scholar]
  13. Ishida M.; Jin H.; Okamoto T. A fundamental study of a new kind of medium material for chemical-looping combustion. Energy Fuels 1996, 10 (4), 958–963. 10.1021/ef950173n. [DOI] [Google Scholar]
  14. Anheden M.; Svedberg G. Chemical-looping combustion in combination with integrated coal gasification. Fuel Energy Abstracts 1997, 38 (2), 107. 10.1016/s0140-6701(97)83128-1. [DOI] [Google Scholar]
  15. Jin H.; Okamoto T.; Ishida M. Development of a novel chemical-looping combustion: synthesis of a solid looping material of NiO/NiAl2O4. Ind. Eng. Chem. Res. 1999, 38 (1), 126–132. 10.1021/ie9803265. [DOI] [Google Scholar]
  16. Adánez J.; de Diego L. F.; García-Labiano F.; Gayán P.; Abad A.; Palacios J. Selection of oxygen carriers for chemical-looping combustion. Energy Fuels 2004, 18 (2), 371–377. 10.1021/ef0301452. [DOI] [Google Scholar]
  17. Adánez J.; Gayán P.; Celaya J.; de Diego L. F.; García-Labiano F.; Abad A. Chemical looping combustion in a 10 kWth prototype using a CuO/Al2O3 oxygen carrier: Effect of operating conditions on methane combustion. Ind. Eng. Chem. Res. 2006, 45 (17), 6075–6080. 10.1021/ie060364l. [DOI] [Google Scholar]
  18. Saeidi S.; Fazlollahi F.; Najari S.; Iranshahi D.; Klemeš J. J.; Baxter L. L. Hydrogen production: Perspectives, separation with special emphasis on kinetics of WGS reaction: A state-of-the-art review. J. Ind. Eng. Chem. 2017, 49, 1–25. 10.1016/j.jiec.2016.12.003. [DOI] [Google Scholar]
  19. Chen S.; Soomro A.; Yu R.; Hu J.; Sun Z.; Xiang W. Integration of chemical looping combustion and supercritical CO2 cycle for combined heat and power generation with CO2 capture. Energy Convers. Manage. 2018, 167, 113–124. 10.1016/j.enconman.2018.04.083. [DOI] [Google Scholar]
  20. Du Y.; Yu Z.; Yang C.; Wang H.; Sun S. Techno-economic Optimization of the Combined Supercritical Carbon Dioxide and Air Brayton Cycles Driven by Copper-Based Chemical Looping Combustion. Energy Fuels 2024, 38 (3), 2305–2318. 10.1021/acs.energyfuels.3c03810. [DOI] [Google Scholar]
  21. Son S. R.; Kim S. D. Chemical-looping combustion with NiO and Fe2O3 in a thermobalance and circulating fluidized bed reactor with double loops. Ind. Eng. Chem. Res. 2006, 45 (8), 2689–2696. 10.1021/ie050919x. [DOI] [Google Scholar]
  22. Monazam E. R.; Breault R. W.; Siriwardane R.; Richards G.; Carpenter S. Kinetics of the reduction of hematite (Fe2O3) by methane (CH4) during chemical looping combustion: A global mechanism. Chem. Eng. J. 2013, 232, 478–487. 10.1016/j.cej.2013.07.091. [DOI] [Google Scholar]
  23. Ma Z.; Liu G.; Lu Y.; Wang J.; Zhang H. Improved redox performance of Fe2O3/Al2O3 oxygen carrier via element doping in chemical looping combustion. Fuel Process. Technol. 2021, 224, 107030 10.1016/j.fuproc.2021.107030. [DOI] [Google Scholar]
  24. Dou B.; Zhao L.; Zhang H.; Wu K.; Zhang H. Renewable hydrogen production from chemical looping steam reforming of biodiesel byproduct glycerol by mesoporous oxygen carriers. Chem. Eng. J. 2021, 416, 127612 10.1016/j.cej.2020.127612. [DOI] [Google Scholar]
  25. Dou B.; Wu K.; Zhang H.; Chen B.; Chen H.; Xu Y. Sorption-enhanced chemical looping steam reforming of glycerol with CO2 in-situ capture and utilization. Chem. Eng. J. 2023, 452, 139703 10.1016/j.cej.2022.139703. [DOI] [Google Scholar]
  26. Rydén M.; Lyngfelt A. Using steam reforming to produce hydrogen with carbon dioxide capture by chemical-looping combustion. Int. J. Hydrogen Energy 2006, 31 (10), 1271–1283. 10.1016/j.ijhydene.2005.12.003. [DOI] [Google Scholar]
  27. Gamwo I.; Jung J.; Anderson R.; Soong Y.. Chemical Looping Combustion System-Fuel Reactor Modeling; National Energy Technology Laboratory (NETL): Pittsburgh, PA, Morgantown, WV, 2007. [Google Scholar]
  28. Rahimpour M. R.; Hesami M.; Saidi M.; Jahanmiri A.; Farniaei M.; Abbasi M. Methane steam reforming thermally coupled with fuel combustion: application of chemical looping concept as a novel technology. Energy Fuels 2013, 27 (4), 2351–2362. 10.1021/ef400026k. [DOI] [Google Scholar]
  29. Abbasi M.; Farniaei M.; Rahimpour M. R.; Shariati A. Enhancement of hydrogen production and carbon dioxide capturing in a novel methane steam reformer coupled with chemical looping combustion and assisted by hydrogen perm-selective membranes. Energy Fuels 2013, 27 (9), 5359–5372. 10.1021/ef400880q. [DOI] [Google Scholar]
  30. Abbasi M.; Farniaei M.; Rahimpour M. R.; Shariati A. Methane dry reformer by application of chemical looping combustion via Mn-based oxygen carrier for heat supplying and carbon dioxide providing. Chem. Eng. Process.: Process Intensif. 2014, 79, 69–79. 10.1016/j.cep.2014.03.004. [DOI] [Google Scholar]
  31. Karimi E.; Forutan H.; Saidi M.; Rahimpour M.; Shariati A. Experimental study of chemical-looping reforming in a fixed-bed reactor: performance investigation of different oxygen carriers on Al2O3 and TiO2 support. Energy Fuels 2014, 28 (4), 2811–2820. 10.1021/ef5003765. [DOI] [Google Scholar]
  32. Wolf J.; Yan J. Parametric study of chemical looping combustion for tri-generation of hydrogen, heat, and electrical power with CO2 capture. Int. J. Energy Res. 2005, 29 (8), 739–753. 10.1002/er.1079. [DOI] [Google Scholar]
  33. Zafar Q.; Mattisson T.; Gevert B. Integrated hydrogen and power production with CO2 capture using chemical-looping reforming redox reactivity of particles of CuO, Mn2O3, NiO, and Fe2O3 using SiO2 as a support. Ind. Eng. Chem. Res. 2005, 44 (10), 3485–3496. 10.1021/ie048978i. [DOI] [Google Scholar]
  34. Zhang Y.; Doroodchi E.; Moghtaderi B. Thermodynamic assessment of a novel concept for integrated gasification chemical looping combustion of solid fuels. Energy Fuels 2012, 26 (1), 287–295. 10.1021/ef201156x. [DOI] [Google Scholar]
  35. Chen S.; Xue Z.; Wang D.; Xiang W. An integrated system combining chemical looping hydrogen generation process and solid oxide fuel cell/gas turbine cycle for power production with CO2 capture. J. Power Sources 2012, 215, 89–98. 10.1016/j.jpowsour.2012.04.087. [DOI] [Google Scholar]
  36. Ozcan H.; Dincer I. Thermodynamic analysis of a combined chemical looping-based trigeneration system. Energy Convers. Manage. 2014, 85, 477–487. 10.1016/j.enconman.2014.06.011. [DOI] [Google Scholar]
  37. Sorgenfrei M.; Tsatsaronis G. Design and evaluation of an IGCC power plant using iron-based syngas chemical-looping (SCL) combustion. Appl. Energy 2014, 113, 1958–1964. 10.1016/j.apenergy.2013.03.089. [DOI] [Google Scholar]
  38. Edrisi A.; Mansoori Z.; Dabir B. Urea synthesis using chemical looping process–Techno-economic evaluation of a novel plant configuration for a green production. Int. J. Greenhouse Gas Control 2016, 44, 42–51. 10.1016/j.ijggc.2015.10.020. [DOI] [Google Scholar]
  39. Aziz M.; Zaini I. N.; Oda T.; Morihara A.; Kashiwagi T. Energy conservative brown coal conversion to hydrogen and power based on enhanced process integration: Integrated drying, coal direct chemical looping, combined cycle and hydrogenation. Int. J. Hydrogen Energy 2017, 42 (5), 2904–2913. 10.1016/j.ijhydene.2016.10.060. [DOI] [Google Scholar]
  40. Mehrpooya M.; Rahbari C.; Moosavian S. A. Introducing a hybrid multi-generation fuel cell system, hydrogen production and cryogenic CO2 capturing process. Chem. Eng. Process.: Process Intensif. 2017, 120, 134–147. 10.1016/j.cep.2017.07.008. [DOI] [Google Scholar]
  41. Chen S.; Xue Z.; Wang D.; Xiang W. Hydrogen and electricity co-production plant integrating steam-iron process and chemical looping combustion. Int. J. Hydrogen Energy 2012, 37 (10), 8204–8216. 10.1016/j.ijhydene.2012.02.098. [DOI] [Google Scholar]
  42. Xu H.; Dong H.; Zhao L.; Cheng D. Exergy Analysis and Modeling of Pilot-Scale Pyrolysis for Magnesium Oxide Preparation from Salt Lake Bischofite Industrial Waste. ACS Omega 2023, 8 (49), 47153–47162. 10.1021/acsomega.3c07165. [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Petrakopoulou F.; Tsatsaronis G.; Morosuk T. Evaluation of a power plant with chemical looping combustion using an advanced exergoeconomic analysis. Sustainable Energy Technol. Assess. 2013, 3, 9–16. 10.1016/j.seta.2013.05.001. [DOI] [Google Scholar]
  44. Ahmadi P.; Dincer I.; Rosen M. A. Thermodynamic modeling and multi-objective evolutionary-based optimization of a new multigeneration energy system. Energy Convers. Manage. 2013, 76, 282–300. 10.1016/j.enconman.2013.07.049. [DOI] [Google Scholar]
  45. Ptasinski K. J.Efficiency of Biomass Energy: An Exergy Approach to Biofuels, Power, and Biorefineries; John Wiley & Sons, Inc.: Hoboken, NJ, USA, 2016. [Google Scholar]
  46. Mutlu Ö. Ç.; Zeng T. Challenges and Opportunities of Modeling Biomass Gasification in Aspen Plus: A Review. Chem. Eng. Technol. 2020, 43 (9), 1674–1689. 10.1002/ceat.202000068. [DOI] [Google Scholar]
  47. Abbasi M.; Farniei M.; Rahimpour M.; Shariati A. Hydrogen production in an environmental-friendly process by application of chemical looping combustion via Ni-and Fe-Based oxygen carriers. Theor. Found. Chem. Eng. 2015, 49 (6), 884–900. 10.1134/S0040579515060019. [DOI] [Google Scholar]

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