Chemical storage of solar energy—kinetics of heterogeneous NH3 and H2SO4 reactions II. Process and reactor design

An important energy recovery step in the ammonium hydrogen sulfate (AHS) cycle is the recombination reaction producing NH4HSO4. It has been determined that the optimum way to accomplish this, and prevent side reactions, is by the heterogeneous gas-liquid reaction of H2SO4 and NH3. A mathematical model is presented and applied to the two reaction zones and a method of numerical solution is discussed. Three horizontal pilot-scale configurations, 0.17 × 106 to 4.2 × 106 kJ/h energy release, are discussed and sizing is presented. The most important conclusion from the work is that the energy can be released most effectively by carrying out the reaction in a double pipe tubular reactor operating in the annular flow regime with both gas and liquid in turbulent flow.