Production of Valuable Materials from Sago Bark Using Subcritical Water Treatment

Abstract

Sago bark is generated as by-product from sago starch industries. Malaysia as one of the biggest exporter of sago starch produces a lot of sago bark wastes which are now burned on-site and underutilized. This study aims to apply subcritical water as a green solvent for hydrolysis of sago bark in order to obtain the value-added products. Inner and outer layers of sago bark were subjected to subcritical water treatment at 180 °C to 320 °C for 5 minutes. Inner layer showed higher yield of total organic carbon and total sugar at 210 °C than the outer layer, 0.40 and 0.67 g/g-dry sample respectively. Both layers had generated similar types of monosaccharides and inner layer showed extremely better yield of glucose, xylose and arabinose with the value of 0.125, 0.123 and 0.019 g/g-dry SB, respectively. Six organic acids were identified and were most favored to produce at a higher temperature. The increasing temperature had led to an apparent tar yields, ~0.40 g/g-dry SB and a huge drop of solid residues, ≥75%. In general, the inner layer was more susceptible to subcritical water treatment than the outer layer with evident yields of all products produced.

Valorization of Agricultural Wastes to Offset Greenhouse Gases (GHGs) Emissions: An Insight in Southeast Asia

“…Malaysia, the second-largest palm oil producer [35] , faces waste management challenges [36] from the oil palm industry's EFB, PKS, fronds, and trunks [37][38][39] . It also generates residues from rice, coconut, pineapple, banana, durian, and sago starch production [22,34,40,41] . The government aims to capitalize on bioenergy from these abundant residues to reduce greenhouse gas emissions [42] .…”

“…Table 3 summarizes valorization pathways for agricultural wastes in Southeast Asia. Rice husk, livestock manure Bioenergy Indonesia Rice husk, cocoa pods, coconut shells, oil palm shells, corn cobs Biochar [33] Oil palm residues such as palm kernels, EFB, fronds, and trunks Bioenergy, value-added products [15] Palm kernel shells, EFB, old trunks, rice husks, rice straw, sugarcane residues (bagasse, tops, leaves) Bioenergy [19,34] Cassava pulp Biogas [1] Cocoa pod waste, rice straw & husk, coconut waste Bioenergy [34] Malaysia Oil palm residues Bioenergy [37] Sago wastes Value-added products [40] Rice and palm oil residues Biocoke [34] Palm oil residues Value-added products [39] Oil palm residues Biofuel [42] Philippines Rice husks Value-added products [13] Rice husks, sawdust, starch Particle board [49] Corn stover, coconut shell Cattle feed, activated carbon, charcoal [50]…”

A Review on Biodegradable Packaging Films from Vegetative and Food Waste

“…Although the functional properties of a majority of vegetative waste-based biofilms are not at par with respect to the technical requirements of commercially established food packaging/edible counterparts in terms of gas/water vapour permeability and mechanical characteristics, there is enough scope to tailor-make these films as per the commercial requirements. Some of these concepts to improve the mechanical and barrier properties of these films include crosslinking, [219,220] nanotechnology, [210,221,222] composites, [120,216,223,224] plasticization, [225,226] etc. A composite film can potentially solve the lacunas faced in pristine films.…”