Development of an Innovative and Green Method to Obtain Nanoparticles in Aqueous Solution from Carbon-Based Waste Ashes.

In this study, an original and green procedure to produce water-based solutions containing nanometric recycled carbon particles is proposed. The nanometric particles are obtained starting from carbon waste ashes, produced by the wooden biomass pyro-gasification plant CMD (Costruzioni motori diesel) ECO20. The latter is an integrated system combining a downdraft gasifier, a spark-ignition internal combustion engine, an electric generator and syngas cleaning devices, and it can produce electric and thermal power up to 20 kWe and 40 kWth. The carbon-based ashes (CA) produced by the CMD ECO20 plant were, first, characterized by using differential scanning calorimetry (DSC) and microcomputed tomography (microCT). Afterward, they were reduced in powder by using a milling mortar and analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectrometry, thermogravimetric analysis (TGA), X-ray diffraction (WAXD) and Fourier-transform infrared (FTIR) spectroscopy. The optimization of an original procedure to reduce the dimensions of the ashes in an aqueous solution was then developed by using ball milling and sonication techniques, and the nanometric dimensions of the particles dispersed in water were estimated by dynamic light scattering (DLS) measurements in the order of 300 nm. Finally, possible industrial applications for the nanomaterials obtained from the waste ashes are suggested, including, for example, inks for Aerosol Jet® Printing (AJ® P).

Biodegradable Carbon-based Ashes/Maize Starch Composite Films for Agricultural Applications.

The aim of this work is the development and characterization of biodegradable thermoplastic recycled carbon ashes/maize starch (TPAS) composite films for agricultural applications. A proper plasticizer, that is, glycerol, was added to a commercial maize starch in an amount of 35 wt.%. Carbon-based ashes were produced by the biomass pyro-gasification plant CMD ECO 20, starting from lignocellulosic wastes. The ashes were added to glycerol and maize native starch at different amounts ranging from 7 wt. % to 21 wt.%. The composite was mixed at 130 °C for 10 min and then molded. The effect of the different amounts of carbon based ashes on the thermal and physical-mechanical properties of the composite was assessed by using several techniques, such as rheology, wide- angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), moisture absorption, degradation and mechanical tests. The presence of the carbon waste ashes allows to improve thermal and durability performances of the thermoplastic starch (TPS) films. It reduces the water absorption of starch matrix and strongly decreases the deterioration of starch, independently from fillers amount, enhancing the lifetime of the TPS films in outdoor conditions. In addition, the waste carbon ashes/maize starch films present an advantage in comparison to those of neat starch; it can biodegrade, releasing the plant nutrients contained in the ashes into the soil. In conclusion, this approach for recycling carbon waste ashes increases the efficiency of industrial waste management, along with a reduction of its impact on the environment.

Catalytic Activity of Oxidized Carbon Waste Ashes for the Crosslinking of Epoxy Resins.

In this study, two different fillers were prepared from carbon-based ashes, produced from the wooden biomass of a pyro-gasification plant, and starting from lignocellulosic waste. The first type was obtained by dry ball-milling (DBA), while the second one was prepared by oxidation in H2O2 of the dry ball-milled ashes (oDBA). The characterization of the fillers included wide-angle x-ray diffraction (WAXD), thermogravimetric, and Fourier-transform infrared spectroscopy (FTIR) analysis. The DBA and oDBA fillers were then tested as possible catalysts for the crosslinking reaction of a diglycidyl ether of bisphenol A (DGEBA) with a diamine. The cure reaction was studied by means of rheometry and differential scanning calorimetry (DSC). The oDBA filler exhibits both a higher catalytic activity on the epoxide-amine reaction than the DBA sample and improved mechanical properties and glass transition temperature. The results obtained indicate, hence, the potential improvement brought by the addition of carbon-based waste ashes, which allow both increasing the flexural properties and the glass transition temperature of the epoxy resin and reducing the curing time, acting as a catalyst for the crosslinking reaction of the epoxy resin.