The effect of chemical activators on the properties of activated carbon from sago waste was conducted in this study by using ZnCl₂, H₃PO₄, KOH, and KMnO₄ chemical solutions. The carbonized sago waste was added to each chemical solution, boiled at 85 °C for 4 h, and heated at 600 °C for 3 h. The porosity, microstructural, proximate, and surface chemistry analyses were carried out using nitrogen adsorption with employing the Brunauer Emmett Teller (BET) method and the Barret-Joyner-Halenda (BJH) calculation, scanning electron microscopy by using energy dispersive spectroscopy, X-ray diffractometer, simultaneous thermogravimetric analysis system, and the Fourier-transform infrared spectroscopy. The results showed that the activated carbon prepared using ZnCl₂ acid had the highest specific surface area of 546.61 m²/g, while the KOH activating agent surpassed other chemicals in terms of a refined structure and morphology, with the lowest ash content of 10.90%. The surface chemistry study revealed that ZnCl₂ and KOH activated carbon showed phenol and carboxylate groups. Hence, ZnCl₂ acid was suggested as activating agents for micropore carbon, while KOH was favorable to producing a mesopore-activated carbon from sago waste.

In the present research, activated carbon-supported sulfonic acid catalysts were synthesized and tested as pretreatment agents for the conversion of switchgrass into glucose. The catalysts were synthesized by reacting sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid with activated carbon. The characterization of catalysts suggested an increase in surface acidities, while surface area and pore volumes decreased because of sulfonation. Batch experiments were performed in 125 mL serum bottles to investigate the effects of temperature (30, 60, and 90 °C), reaction time (90 and 120 min) on the yields of glucose. Enzymatic hydrolysis of pretreated switchgrass using Ctec2 yielded up to 57.13% glucose. Durability tests indicated that sulfonic solid-impregnated carbon catalysts were able to maintain activity even after three cycles. From the results obtained, the solid acid catalysts appear to serve as effective pretreatment agents and can potentially reduce the use of conventional liquid acids and bases in biomass-into-biofuel production.

There is a significant interest in employing solid acid catalysts for pre-treatment of biomasses for subsequent hydrolysis into sugars, because solid acid catalysts facilitate reusability, high activity, and easier separation. Hence the present research investigated pretreatment of four lignocellulosic biomasses, namely Switchgrass (Panicum virgatum L ‘Alamo’), Gamagrass (Tripsacum dactyloides), Miscanthus (Miscanthus × giganteus) and Triticale hay (Triticale hexaploide Lart.) at 90°C for 2 h using three carbon-supported sulfonic acid catalysts. The catalysts were synthesized via impregnating p-Toluenesulfonic acid on carbon (regular) and further impregnated with iron nitrate via two methods to obtain magnetic A and magnetic B catalysts. When tested as pre-treatment agents, a maximum total lignin reduction of 17.73±0.63% was observed for Triticale hay treated with magnetic A catalyst. Furthermore, maximum glucose yield after enzymatic hydrolysis was observed to be 203.47±5.09 mg g–1 (conversion of 65.07±1.63%) from Switchgrass treated with magnetic A catalyst. When reusability of magnetised catalysts were tested, it was observed that magnetic A catalyst was consistent for Gamagrass, Miscanthus × Giganteus and Triticale hay, while magnetic B catalyst was found to maintain consistent yield for switchgrass feedstock. Our results suggested that magnetised solid acid catalyst could pre-treat various biomass stocks and also can potentially reduce the use of harsh chemicals and make bioenergy processes environment friendly.

This study aims to develop sago starch-based bioplastics with the addition of modifying agents such as acetic acid, chitosan, and glycerin to improve mechanical properties, elongation, and biodegradability. The results showed that the optimal combination was reached at 4% acetic acid and 2% chitosan concentration, resulting in the highest tensile strength of 8 MPa, elongation at break of 26%, and degradation rate of 70%. At this condition, the bioplastic matrix has an optimal balance between strength, flexibility, and degradability. Increasing the acetic acid concentration to 6% caused a decrease in tensile strength to 4.2 MPa and elongation at break to 14%, indicating degradation of the matrix structure due to excess acid. Chitosan also affected the mechanical properties, where increasing its concentration from 2% to 4% tended to decrease the elongation at break. The degradation rate tended to increase with higher concentrations of acetic acid, reaching 82% at 6% acetic acid concentration with 2% chitosan, while higher concentrations of chitosan (4%) slowed down the degradation due to a denser and stronger matrix structure. Overall, the combination of sago starch, acetic acid, chitosan, and glycerin produced bioplastics that have improved mechanical properties, water resistance, and environmental friendliness, making them a potential alternative to replace conventional plastics in various industrial applications. These findings support the development of environmentally friendly materials that can reduce the negative impacts to the environment in general and in Papua as the local producer of Sago.