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

Abstract

In this novel paper, application of chemical looping combustion (CLC) instead of furnace in a steam reformer assisted by Pd−Ag hydrogen perm-selective membranes (CLC-SRM) for CO 2 capture and hydrogen production has been analyzed. NiO18-αAl 2 O 3 particles have been employed as oxygen carriers in CLC-SRM. These particles have shown very high reactivity and allow for working at high temperatures in a CLC process with full methane conversion due to Ni-based oxygen carriers. In the CLC-SRM configuration, the air reactor (AR) and fuel reactor (FR) operate in fast and bubbling fluidization, respectively. In this configuration, reforming tubes are located vertically inside the AR so that methane steam reforming occurs in these fixed bed catalytic tubes that have been covered by the membranes. A steady state one-dimensional heterogeneous catalytic reaction model is applied to analyze the performance of CLC-SRM. Performance of conventional steam reformer (CSR) has been compared with CLC-SRM by investigation of important parameters such as temperature, mole fractions, heat of reaction, rate of reactions, methane conversion, and hydrogen production. The simulation results of CLC-SRM show that by employing CLC-SRM, methane conversion and hydrogen production increase 7.54% and 25.48%, respectively, in comparison with CSR. In addition, results indicated that by increasing feed flow rate of FR from 90 to 180 mol s −1 methane conversion and hydrogen production can increase 16.73% and 40%, respectively. In CLC-SRM, the total amount of methane consumed in the FR and combustion efficiency increases to 1 in the FR, and a huge amount of almost pure carbon dioxide (410 ton day −1 ) can be captured by removal of water from the FR outlet stream with condensation.

Promotion of Ca-Co Bifunctional Catalyst/Sorbent with Yttrium for Hydrogen Production in Modified Chemical Looping Steam Methane Reforming Process

“…Therefore, it could be found that carbon deposition did not occur on the surface of bifunctional catalyst/sorbents, which could be due to the basic and natural properties of calcium oxide and yttrium promoter. On the other hand, the cobalt oxide (Co 3 Figure 3 illustrates the FESEM images of fresh samples including synthesized calcium, Ca-9Co and Ca-9Co-4.5Y. As shown in Figure 3b the Ca-9Co catalyst has a dense structure with more aggregated particles.…”

“…This matter has increased worldwide environmental concern [1][2][3][4]. Further improvements in the efficiency of energy production processes and the use of environmental friendly energy carriers are effective methods to overcome these problems [5,6].…”

“…According to Equation (3), an elimination product is necessary for the complete conversion of CO to CO 2 and producing high purity hydrogen. If a product of WGSR were removed during the process, the equilibrium would be shifted to the right and the amount of produced hydrogen increases (Le Chatelier's principle).…”

“…In their studies, OCs and sorbents were mixed and used in SECLR process to produce hydrogen with high purity. Buelens et al [32] 3 as solid CO 2 sorbent in SDRM process for producing high purity syngas. Dou et al [33] studied NiO/NiAl 2 O 4 oxygen carrier and a solid sorbent such as calcium oxide in SECLR of glycerol.…”

Hydrogen Production from Cyclic Chemical Looping Steam Methane Reforming over Yttrium Promoted Ni/SBA-16 Oxygen Carrier

“…H 2 has been widely identified as a favorable clean energy carrier because of its non-polluting nature and high specific energy density (120.7 kJ/g) [7][8][9]. Recently, hydrogen can be produced by applying novel techniques with lower cost [9][10][11]. Reforming of fossil fuels, photo-catalytic water splitting, electrolysis and biomass gasification are hydrogen production technologies [9,[12][13][14][15].…”