Kelly Hawboldt

The hydrolysis reaction of the copper‐chlorine (Cu‐Cl) cycle is examined in this paper to better understand the corresponding reaction kinetics and mass transfer resistance. The experiment was operated at a temperature of 390°C at atmospheric pressure. The reaction is heterogeneous in which solid reactant CuCl₂ and gaseous reactant H₂O produce Cu₂OCl₂ (s) and HCl(g). Heterogeneous behaviour of the reaction causes a resistance to mass transfer of gaseous reactant H₂O. The resistance in internal diffusion and a surface reaction with mass transfer was analyzed with respect to the initial solid reactant particle size using a shrinking core model (SCM). The experimentally determined reaction and conversion rates of hydrolysis reaction with respect to time are presented.

Pressurized water extraction techniques (ASE and SCWE) are potentially more sustainable for extracting bioactive compounds from beach-cast brown algae than conventional solvent extraction on both small and large scales.

Chitin is a polymer of N-acetylglucosamine and provides structure and stability to the exoskeleton of crustaceans, insects and fungal cell walls. Intermolecular hydrogen bonds between polymer chains create a very tight crystalline fibre network with excellent mechanical properties. Chitins’ antimicrobial properties and high biocompatibility make it an attractive polymer source for the production of nanomaterials such as hydrogels, films, or highly porous nano foams. To date, commercial utilization of native chitin has been limited due to its insolubility in aqueous solutions and most common solvents. Instead, chemical modifications such as deacetylation or depolymerization are used to make chitin soluble and easier to work with but as a consequence, chitin loses some of its mechanical stability. Other approaches for chitin dissolution employ toxic chemicals, potentially negating biomedical and food applications. This review summarizes pre-treatment methods for dissolution or fibrillation of native chitin fibre using non-toxic and mechanical approaches and how it relates to the macrostructure of the species of origin.