This thesis is based around the production of H2 via a process called Sorbent Enhanced Steam Reforming (SESR), which has the potential to drastically reduce CO2 emissions from H2 production therefore abating climate change. SESR is a combination of traditional Steam Methane Reforming (SMR) and Calcium Looping (CaL, a form of Carbon Capture and Storage, CCS), whereby the CaL sorbent removes CO2 from the gas stream and drives the reactions equilibrium to produce more H2. With the application of biomass as the fuel feedstock this process has the potential to produce H2 with net-negative CO2 emissions.
Two main areas of work were conducted within this thesis, namely: examining the performance of CaL sorbents and novel sorbents under industrial conditions, and the development of combined multifunctional sorbent and catalyst particles for SESR with biomass. These particles were tested within a reactor that was specifically constructed for this set of work.
A detailed investigation into the effects of various parameters on the rate of limestone calcination was conducted within an atmospheric fluidised bed reactor utilising high-temperatures and CO2 partial pressures. These conditions would typically be present within a CaL/SESR calciner and thus kinetic data with this environment was determined. Further to this, a single particle model was developed to shed light on the variances observed when calcining limestone in the presence of CO2 and steam or CO2 and N2. The application of a novel synthetic sorbent was also investigated under similar calcination conditions showing the impacts on the sorbents carrying capacity caused by high-temperature CO2 sintering.
A mild-pressure, high-temperature spout-fluidised bed reactor was constructed for the purpose of continuous biomass feeding for SESR. Combined particles of catalyst, sorbent and a dicalcium silicate support were tested. These combined particles were manufactured utilising a simple and inexpensive method. An enhanced H2 yield of 120 gH2/kgbiomass was produced at ~75 % purity at a stoichiometric steam to carbon ratio.