In this study, nanocrystalline cellulose (NCC) was synthesized using mixed H ₂ SO ₄ /formic acid hydrolysis from waste cassava pulp produced in Northern Mindanao, Philippines. The study investigated the extraction yield with respect to acid concentration, hydrolysis temperature, and time; the optimal set of such factors; and the characteristics of the optimized NCC. The raw material was pretreated with 4 wt% NaOH and bleached with 4% (w/v) NaOCl. Hydrolysis conditions were formic acid concentration of 50–88 wt%, temperature of 70–90°C, and time of 1–6 hours. Five (5) wt% H ₂ SO ₄ was also added as a catalyst. Based on the results, increased factor values contributed to higher extraction yields, but too much resulted in a decrease. Optimization resulted in the set of factors (71 wt% formic acid, 77°C, and 3.6 hours) with a yield of 67.272% ± 2.295%. FTIR analysis indicated effective removal of lignin and hemicellulose during the pretreatment. Furthermore, SEM images and DLS indicate nano-size dimensions with hydrodynamic diameters from 15 nm to 687 nm and a zeta potential of -14.3 mV. The NCC produced in this study has been found to have comparable extraction yield as previously reported with smaller reported hydrodynamic diameters and less tendency for self-aggregation.

In the Philippines’ agricultural setup, pre-harvest cacao (Theobroma cacao) fruits are wrapped with low-density polyethylene (LDPE) for moisture retention and damage protection. Responding to the growing concern for its waste volume and scarcity of treatment, this research explores the co-hydrothermal carbonization (co-HTC) of cacao shells (CS) and LDPE as a method to convert agricultural waste with plastic into hydrochar for potential energy applications. Thus, observations on the thermal, physicochemical, and morphological changes from feedstocks to hydrochar are carried out. Optimal conditions of 200 °C for 60 min resulted in hydrochar with 21.11 MJ/kg and appreciable thermal properties. SEM micrographs show that hydrochar had increased surface area, a good fuel characteristic, and surface flaking on oversized LDPE film, suggesting relative LDPE degradation. EDX analysis reveals C, K, Ca, and Zn metals that affect chemical pathways. FTIR analysis further supports chemical synergy by preservation of functional groups innate from both parent materials. Kinetic and thermal evolutions are also investigated to reveal the influence of pretreatment on the stability of cacao shell-dominated hydrochar and the effectivity of biomass integration to facilitate relatively easier cracking of LDPE. The findings support co-HTC as a viable technology to enhance the circular economy by valorizing LDPE and cacao shells while promoting energy recovery and solid fuel production.

In the Philippine agricultural setup, pre-harvest cacao (Theobroma cacao) fruits are wrapped with low-density polyethylene (LDPE) for moisture retention and damage protection. Responding to the growing concern for its waste volume and scarcity of treatment, this research explores the co-hydrothermal carbonization (co-HTC) of cacao shells (CS) and LDPE as a method to convert agricultural waste with plastic into hydrochar of potential energy applications. Thus, observations on the thermal, physicochemical, and morphological changes from feedstocks to hydrochar are carried out. Optimal conditions of 200 °C for 60 minutes resulted in hydrochar with 21.11 MJ/kg and appreciable thermal properties. SEM micrographs show rough and porous structures of hydrochar powder and presence of cracks on oversized LDPE film, while EDX analysis reveals C, K, Ca, and Zn metals that affects chemical pathway. FTIR analysis further supports chemical synergy by preservation of functional groups innate from both parent materials, as well as relative LDPE degradation due to chain scissoring and oxidative reactions. Kinetic and thermal evolutions are also investigated to reveal influence of pretreatment to the stability of cacao shells-dominated hydrochar and the effectivity of biomass integration to facilitate relatively easier degradation of LDPE. The findings support co-HTC as a viable technology to enhance the circular economy by valorizing LDPE and cacao shells while promoting energy recovery.