Equilibrium conversion in Cu–Cl cycle multiphase processes of hydrogen production

Convective heat transfer and solid conversion of reacting particles in a copper(II) chloride fluidized bed

“…The heat transfer in a gas-solid two-phase flow undergoing a chemical reaction within a fluidized bed is determined by simultaneously solving the mass and energy balance equations for the bed. The conversion of cupric chloride solid and steam depends on the bed operating conditions and the equilibrium conversion (Daggupati et al, 2009(Daggupati et al, , 2010. By changing the operating conditions, such as the bed inventory or height of the bed material, the conversion of reactants may be achieved close to equilibrium conversion at a given superficial velocity, temperature, and pressure.…”

“…The superficial velocity of steam, which is taking part in the reaction, represents the mass flow rate of reactant required for the reaction. The equilibrium conversion of solid may be estimated at a given reactant steam to cupric chloride (CuCl 2 ) mole ratio, pressure, and temperature, using the following equation (Daggupati et al, 2009):…”

“…In both cases, hydrolysis of cupric chloride (CuCl 2 ) is a common intermediate step required to split water into hydrogen chloride gas (HCl) and copper-oxychloride solid (Cu 2 OCl 2 ) at temperatures between 350 and 400 1C and 1 bar pressure. Daggupati et al (2009) performed a thermodynamic equilibrium analysis for the chemical reaction steps (reaction steps 3 and 4 in Table 1) of the Cu-Cl cycle. A thermodynamic equilibrium analysis of the hydrolysis reaction (reaction step 3 in Table 1) shows that it requires a high mole ratio of steam per unit mole of cupric chloride to complete the conversion of solid.…”

Experimental study of gaseous effluent and solid conversion in a fluidized bed hydrolysis reactor for hydrogen production

“…Similarly, a pneumatic nebulizer with a counter-current flow design achieved high conversion of CuCl 2 [8]. The operating temperature of a hydrolysis reactor can have significant impacts on the conversion extent, with higher conversions favoring higher temperatures [9]. Ferrandon et al [8] identified the undesired Cl 2 production in an experimental hydrolysis spray reactor using CuCl 2 , when the operating temperature increases beyond 400 C. Decreasing the system pressure can also increase product yields [10], with the added benefit of limiting copper (I) chloride (CuCl) production.…”

“…Thus, nearly complete conversion of CuCl 2 is achieved at a temperature of 375 C. In a thermodynamic analysis of the equilibrium constant during the CuCl 2 hydrolysis reaction, Daggupati et al [9] predicted around 400 C as the desired temperature to achieve complete conversion.…”