Evaluation of the Effect of CaO on Hydrogen Production by Sorption-Enhanced Steam Methane Reforming

Abstract

The effect of heat released during CaO adsorption on sorption-enhanced steam methane reforming for hydrogen production is insufficiently understood. On this basis, Aspen Plus is used to study the effect of steam methane reforming on hydrogen production without/with CaO. At 700 °C and an O 2 inflow of 7 mol/h, the molar flow and molar percentages of H 2 are 20.62 and 67.35%. After adding CaO, at 700 °C with 4.5 mol/h of CaO, the heat release of CaO adsorption is 1.32 MJ/h, and the O 2 inflow reduces to 4.3 mol/h. The molar flow and molar percentage of H 2 are 22.80 mol/h and 85.94%. When 1.2 mol/h CH 4 is combusted for CaCO 3 decomposition in the calciner, regenerated CaO is transferred to the reforming reactor for calcium cycling, which consumes 2.4 mol/h of O 2 . For the entire cycle, 6.7 mol/h of O 2 .

Enhancing CO and H2 Production in Propane Dry Reforming in Excess of CO2

“…The growth in global sustainable energy demands more blue hydrogen for zero-emission vehicles and chemical plants. − Also, efforts to decarbonize the fossil fuel-based petrochemical industry have surged for more CO 2 capture and utilization. Dry reforming would be an attractive route to increase syngas production (CO and H 2 ). − Dry reforming of propane remains a challenging reaction, as it delivers low yields of syngas products with moderate conversion of both CO 2 and C2–C3 − compared to the higher performance of methane dry reforming. , Figure presents the thermodynamics of C1–C3 dry reforming in the form of Gibbs free energy versus temperature, showing that dry reforming of C2–C3 requires lower reaction temperatures than dry reforming of methane. , Specifically, propane appears more favorable at notably lower temperatures, while dry reforming of ethane and methane noticeably requires higher temperatures. Ultimately, the utilization of CO 2 for C2–C3 dry reforming produces more moles of CO and hydrogen, as described in eqs –. normald ry reforming of methane : nobreak0em0.1em⁡ CH 4 nobreak0em0.1em⁡ + nobreak0em0.1em⁡ CO 2 nobreak0em0.1em⁡ → nobreak0em0.1em⁡ 2 CO nobreak0em0.1em⁡ + nobreak0em0.1em⁡ 2 H 2 ( Δ H 298 ° ⁡ 249 ⁡ kJ mol − 1 ) normald ry reforming of ethane : nobreak0em0.1em⁡ nobreak0em0.1em⁡ normalC 2 normalH 6 ⁡ + ⁡ 2 CO 2 ⁡ → ⁡ 4 CO ⁡ + <...…”

“…Dry reforming would be an attractive route to increase syngas production (CO and H 2 ). 4 − 6 Dry reforming of propane remains a challenging reaction, as it delivers low yields of syngas products with moderate conversion of both CO 2 and C2–C3 7 − 9 compared to the higher performance of methane dry reforming. 4 , 10 Figure 1 presents the thermodynamics of C1–C3 dry reforming in the form of Gibbs free energy versus temperature, showing that dry reforming of C2–C3 requires lower reaction temperatures than dry reforming of methane.…”

Synthesis and Catalytic Performance of Mo2C/MoS2 Composite Heterojunction Catalysts

“…Hydrogen has emerged as a paragon of clean energy carriers, embodying a prodigious potential for high energy yield per mass (142 MJ kg −1 ), dwarfing even the venerable fossil fuels, bolstering its prominence at the pinnacles of energy research. The gamut of prevalent hydrogen fabrication techniques encompasses photocatalytic [2,3] and electrolytic hydrogen generation [4][5][6], biomass enzymatic degradation [7,8], and conventional fossilfuel-based hydrogen extraction [9,10]. For example, Marjeta et al [11] synthesized efficient photocatalysts by epitaxial growth of SrTiO 3 on Bi 4 Ti 3 O 12 substrates.…”