Abstract
The ultimate objective of this research is to study the behaviour of guluronic acid (GA) during hydrothermal treatment. The experimental works started with preparation of GA through partial hydrolysis of alginic acid with hydrochloric acid (HCl). The separation of GA from its hydrolysate was performed based on solubility at pH 2.85 where GA was collected as insoluble precipitate. Subsequently, GA was dissolved in sodium hydroxide (NaOH) prior to feeding into a continuous flow reactor. The experiment was conducted at temperature between 210 to 250 ℃ while residence time was fixed at 100 s. The liquid product was analysed with HPLC equipped with sugar column (Shodex KS-802). The results demonstrated significant reduction of GA concentration. The kinetics parameters which are activation energy (E_a) and pre-exponential factor (A) were calculated as 25.1 kJ/mol and 20.6 s^<-1>, respectively. In summary, the degradation characteristics of GA under hydrothermal condition was clearly elucidated.
