Grazia Totaro

Biowaste biorefinery in Europe: opportunities and research & development needs.

This review aims to explore the needs and opportunities of research & development in the field of biowaste biorefinery in Europe. Modern industry in recent years is giving its close attention on organic waste as a new precious bioresource. Specific biowaste valorisation pathways are focusing on food processing waste, being food sector the first manufacture in Europe. Anyway they need to be further tested and validated and then transferred at the larger scale. In particular, they also need to become integrated, combining biomass pretreatments and recovery of biogenic chemicals with bioconversion processes in order to obtain a large class of chemicals. This will help to (a) use the whole biowaste, by avoiding producing residues and providing to the approach the required environmental sustainability, and (b) producing different biobased products that enter different markets, to get the possible economical sustainability of the whole biorefinery. However, the costs of the developed integrated processes might be high, mostly for the fact that the industry dealing with such issues is still underdeveloped and therefore dominated by high processing costs. Such costs can be significantly reduced by intensifying research & development on process integration and intensification. The low or no cost of starting material along with the environmental benefits coming from the concomitant biowaste disposal would offset the high capital costs for initiating such a biorefinery. As long as the oil prices tend to increase (and they will) this strategy will become even more attractive.

Poly(butylene succinate) bionanocomposites: a novel bio-organo-modified layered double hydroxide for superior mechanical properties

Bionanocomposites based on poly(butylene succinate) and a novel organo-modified layered double hydroxide have been prepared by in situ polymerization. In order to enhance the compatibilization of the inorganic filler with the polymer matrix, an oligomer of PBS was intercalated between the layers of the clay. Composites with different percentages of filler (1, 3, 5, 10 wt%) and two different divalent cations (Zn or Mg) were prepared. The thermal, rheological and mechanical properties of the samples were investigated. The results showed that the materials feature a high thermal stability, more specifically so for the composites containing Zn2+ cations. Rheological investigations highlighted a significant chain extender effect of the filler toward the matrix, thus revealing a huge reinforcing effect imparted by the clays, especially for composites with Mg2+ cations. Such findings were also supported by an increase up to 30% of the tensile and flexural strength for a PBS composite loaded with 3 wt% of Mg/Al-LDH, thus suggesting a uniform level of dispersion and a pronounced interfacial interaction between the filler and polymer.

Marinobacter sp. from marine sediments produce highly stable surface-active agents for combatting marine oil spills

BackgroundThe application of chemical dispersants as a response to marine oil spills is raising concerns related to their potential toxicity also towards microbes involved in oil biodegradation. Hence, oil spills occurring under marine environments necessitate the application of biodispersants that are highly active, stable and effective under marine environment context. Biosurfactants from marine bacteria could be good candidates for the development of biodispersant formulations effective in marine environment. This study aimed at establishing a collection of marine bacteria able to produce surface-active compounds and evaluating the activity and stability of the produced compounds under conditions mimicking those found under marine environment context.ResultsA total of 43 different isolates were obtained from harbor sediments. Twenty-six of them produced mainly bioemulsifiers when glucose was used as carbon source and 16 were biosurfactant/bioemulsifiers producers after growth in the presence of soybean oil. Sequencing of 16S rRNA gene classified most isolates into the genus Marinobacter. The produced emulsions were shown to be stable up to 30xa0months monitoring period, in the presence of 300xa0g/l NaCl, at 4xa0°C and after high temperature treatment (120xa0°C for 20xa0min). The partially purified compounds obtained after growth on soybean oil-based media exhibited low toxicity towards V. fischeri and high capability to disperse crude oil on synthetic marine water.ConclusionsTo the best of our knowledge, stability characterization of bioemulsifiers/biosurfactants from the non-pathogenic marine bacterium Marinobacter has not been previously reported. The produced compounds were shown to have potential for different applications including the environmental sector. Indeed, their high stability in the presence of high salt concentration and low temperature, conditions characterizing the marine environment, the capability to disperse crude oil and the low ecotoxicity makes them interesting for the development of biodispersants to be used in combatting marine oil spills.

Retting Process as a Pretreatment of Natural Fibers for the Development of Polymer Composites

The development of high-performance materials made from natural resources is increasing worldwide. Within this framework, natural fiber reinforced polymeric composites now experience great expansion and applications in many fields, ranging from the automotive to the construction sector. The great challenge in producing composites containing natural fibers and with controlled features is connected to the great variation in properties and characteristics of fibers. The quality of the natural fibers is largely determined by the efficiency of the treatment process and can dramatically influence the properties of the final composites. The overall fiber extraction processes, applied to vegetable fibers, is called retting and consists in the separation of fiber bundles from the cuticularized epidermis and the woody core cells. Today, many efforts are being made to optimize the retting methods in terms of fiber quality production, reduction of environmental issues and production costs. This chapter aims to provide a classification and an overview of the retting procedures that have been developed during years and are applied to extract mainly bast fibers.

Bio-Based PA11/Graphene Nanocomposites Prepared by In Situ Polymerization

Bio-based polyamide 11 (PA11)-graphene nanocomposites with different filler concentrations (0.25, 0.5, 0.75, 1.5 and 3 wt%) were prepared by In Situ polymerization starting from a water dispersed suspension of graphene nanoplatelets. The effects of the incorporation of the filler were studied in terms of molecular, morphological, thermal and dynamic mechanical properties of the final materials. During the crystallization process from the melt, the filler induces a notable nucleating effect even if the crystal growth rate tends to decrease. The glass transition temperature tends to shift to higher temperatures indicating a decrement of the molecular mobility. Thermal stability is enhanced confirming a good filler dispersion into the matrix. Mechanical reinforcement, investigated by means of a dynamic mechanical thermal analyzer was also highlighted. It was observed that a graphene concentration of 0.75 wt% induces the highest final performances.