Simultaneous Fe₃O₄ Nanoparticle Formation and Catalyst-Driven Hydrothermal Cellulose Degradation

Abstract

Breakdown and utilization of cellulose are critical for the bioenergy sector; however, current cellulose-to-energy conversion schemes often consume large quantities of unrecoverable chemicals, or are expensive, due to the need for enzymes or high temperatures. In this paper, we demonstrate a new method for converting cellulose into soluble compounds using a mixture of Fe 2+ and Fe 3+ as catalytic centers for the breakdown, yielding Fe 3 O 4 nanoparticles during the hydrothermal process. Iron precursors transformed more than 61% of microcrystalline cellulose into solutes, with the composition of the solute changing with the initial Fe 3+ concentration. The primary products of the breakdown of cellulose were a range of aldaric acids with different molecular weights. The nanoparticles have concentration-dependent tuneable sizes between 6.7 and 15.8 nm in diameter. The production of value-added nanomaterials at low temperatures improves upon the economics of traditional cellulose-to-energy conversion schemes with the precursor value increasing rather than deteriorating over time.

Synthesis of a Magnetic Nanostructured Composite Sorbent Only from Waste Materials

“…Lowering the reaction temperature will cause a similar effect as decreasing the reaction time, although in this case, it is more likely that the reduction in ferric ions is the step that cannot take place to the full extent. This can be concluded from the fact that the amounts of the product also decreased significantly (Table 2), more than for the shortening of reaction time (3c), and also because it is known that the temperatures needed for reduction in ferric to ferrous ions for polyol [58] and hydrothermal reactions [59,60] are higher (depending on the reaction conditions about 433.15-473.15 K). In the case of imbalanced quantities of starting materials, an under-(3g) or overreduction (3h) can take place, decreasing the overall magnetization of the material.…”

Geometric Design Optimisations Towards Improved Power Production Within Alkaline Carbohydrate Fuel Cells

“…3 Currently, carbohydrate to electricity schemes typically involve multiple processing stages to produce energy. 4,5 Carbohydrates are currently either anaerobically digested to produce methane, which includes steps such as hydrolysis, acido-and aceto-genesis and methane production, or fermented into bio-ethanol, which requires carbohydrate fermentation, purification and distillation. 4,6 In both cases, the final product is generally combusted in a heat engine, liberating the energy at efficiencies well below those typically offered by electrochemical fuel cells.…”