Continuous isomerization of glucose to fructose using activated
hydrotalcite catalyst: Effects of reaction conditions
Abstract
Isomerization of glucose to fructose was studied over activated
hydrotalcite as a catalyst in a continuous-flow tubular reactor. The
synthetic hydrotalcite (HT), calcined hydrotalcite (HT-C) and activated
hydrotalcite (calcined-rehydrated hydrotalcite (HT-C-R)) were
characterized by TGA, XRD, BET surface area, and FT-IR analyses. The
effects of operating conditions, including reaction temperature and
retention time (in terms of both catalyst loading and feeding flow rate)
on the isomerization reaction, were investigated. Glucose conversion and
fructose selectivity were found to be more strongly dependent on
retention time than reaction temperature. The fructose yield was mostly
dependent on the feeding flow rate, and its maximum value of 18%
corresponded to the lowest flow rate of 0.5 ml/min. The regenerated
hydrotalcite catalyst showed that the catalyst activity could be
restored through the calcination-rehydration process, and it showed good
potential for recycling and reusability.