Ricerc@Sapienza

Biotechnologic processes based on microalgae cultivations have had an increasing interest from the early 2000s. Microalgae are microorganisms able to produce and accumulate a large variety of industrially relevant compounds starting from renewable and cheap resources. However, 3–10 € per kg of dry biomass is the minimum cost for microalgae biomass production that has been estimated by different studies published in 2016. This high cost restricts industrial applications only to the production of high-value products.

Carbon (C) storage and its dynamics in vegetation and soil are important for predicting how terrestrial ecosystem carbon pools may change as climate and land use change in the next future. In this context, the organic fraction of the C stored in the above-ground biomass (CA), below-ground biomass (CB), deadwood mass (CD), litter (CL) and soil (CS) was estimated for different plant land-cover categories: forests (i.e.

5-hydroxymethylfuraldehyde (5-HMF) is the main product of the thermal acid-catalysed dehydration of monosaccharides and together with other furan compounds is considered a platform molecule for the production of chemicals and fuels. Identifying alternative catalytic strategies to synthesize 5-HMF represents a key-step to increase reaction selectivity and reduce degradation-by-product yields. In this regard, mass spectrometry has proved to be an useful tool for studying reaction mechanisms in absence of solvent molecules.

The estimation of aboveground biomass is commonly recognized for global relevance because of the vegetation role in the carbon cycle. Both active and passive microwave sensors can significantly contribute to this goal because of their high sensitivity to water content and high penetration at lower frequencies (L-/P-bands).

Hydrothermal liquefaction of oak wood was carried out in tubular micro reactors at different temperatures (280–330 °C), reaction times (10–30 min), and catalyst loads (10–50 wt%) using metallic Ni catalysts. For the first time, to enhance the catalytic activity of Ni particles, a coating technique producing a nanostructured surface was used, maintaining anyway the micrometric dimension of the catalyst, necessary for an easier recovery. The optimum conditions for non-catalytic liquefaction tests was determined to be 330 °C and 10 min with the bio-crude yield of 32.88%.

The thermal properties of artichoke waste, a relatively rich source of phenolic antioxidants, were investigated before and after phenolic recovery in order to assess its suitability as a source of bioproducts and bioenergy. The two main fractions of the waste, the bracts and the stems, were submitted to solvent extraction with aqueous ethanol (0, 50, 100% v/v) and the resulting extracts were assayed for total phenolics, flavonoids and antioxidant activity. The polyphenol content of stems was 51.10 ± 0.74 mg GAE/g and that of bracts was 24.58 ± 0.57 mg GAE/g.

The problem of the production of tar along with syngas in gasification processes limits the diffusion of this technology. In this work, the tar abatement capacity of four bed materials was investigated. The bed materials, namely, activated carbon, aluminum oxide, olive residue char, and pumice stone, listed in order of decreasing surface area, were chosen to investigate their effect on the abatement capacity. Furthermore, the deactivation of these materials with time on stream was measured, and the results were used to develop a kinetic model.

The compliance of the chemical and environmental requirements for using woody biomass fly ash (WBFA) as a mineral admixture in cement-based materials was studied in terms of the use of the cement-biomass fly ash concrete where the fluids surrounding and interacting with it renew themselves over time. The study was preceded by a preliminary characterization of WBFA whose results showed that the European chemical requirements (EN 450-1, 2012) established for the reuse of coal fly ash in cement-based materials (there is no normative for WBFA) were met except for the chloride content.

This chapter covers sustainable techniques to perform a market-neutral biomass fractionation developed in laboratories, techniques targeting a substantial incorporation of the green chemistry principles, the paradigmatic shifts, and the role of green solvent technology in designing the future of biorefineries.

In this work pentose sugar (D-xylose, D-ribose and D-arabinose) gas phase dehydration reaction was investigated by means of mass spectrometric techniques and theoretical calculations. The ionic species derived from the dehydration reaction of protonated D-ribose and D-arabinose were structurally characterized by their fragmentation patterns and the relative dehydration energies measured by energy resolved CAD mass spectra. The results were compared with those recently obtained for D-xylose in the same mass spectrometric experimental conditions.