Many recent studies focused on the research of thermal treated biomass in order to replace fossil fuels. These studies improved the knowledge about pretreated lignocellulosics contribution to achieve the goal of renewable energy sources, reducing CO2 emissions and limiting climate change. They participate in renewable energy production so that sustainable consumption and production patterns can by ensured by meeting Goals 7 and 12 of the 2030 Agenda for Sustainable Development. To this end, the subject of the present study relates to the enhancement of the thermal energy content of barley straw through torrefaction. At the same time, the impact of the torrefaction process parameters, i.e., time and temperature, was investigated and kinetic models were applied in order to fit the experimental data using the severity factor, R0, which combines the effect of the temperature and the time of the torrefaction process into a single reaction ordinate. According to the results presented herein, the maximum heating value was achieved at the most severe torrefaction conditions. Consequently, torrefied barley straw could be an alternative renewable energy source as a coal substitute or an activated carbon low cost substitute (with/without activation treatment) within the biorefinery and the circular economy concept.

The purpose of this study was first to examine and then to maximize, the adsorbency of torrefied barley straw, in order to remove basic dyes like Methylene Blue (MB) from wastewater. On the other hand, the effect of the torrefaction process on the heating value of the material was investigated. Moderate modification conditions (220 ºC, 20 min) were found to maximize adsorbency of modified barley straw. The experimental data were simulated by a pseudo-second order kinetic model. The torrefaction also significantly enhanced the higher heating value of the pretreated barley straw compared to the untreated material. Specifically, the calorific value increased from 16.1 MJ/kg to 19.4 MJ/kg for sample torrefied at 240 ºC during 40 min. Consequently, the torrefaction of barley straw leads to the coproduction of material with enhanced energy content in combination with improved adsorption capacity. The coproduction of energy and adsorbents from lignocellulosic biomass takes into account (i) the biorefinery (more than one product) and (ii) the Industrial Ecology concept (using solid waste to clean wastewater pollution).

This study investigates air pollution dispersion in urban areas by means of Computational Fluid Dynamics (CFD). The commercial CFD software FLUENT was used to implement two different turbulence simulation methods (RANS and LES), in domains similar to complex urban environments. Particularly, different combinations of roof shapes were studied and simulation results of pollutant (ethane) concentrations were compared against experimental data. The building height (H) to the neighbour building distance (B) ratio was also taken into consideration. Previous studies showed that both RANS and LES models are accurate enough to predict pollutant concentrations fields in B/H = 1. In the present study the incapability of RANS models to predict accurately pollutant concentration in B/H = 0.5 for all roof shapes configurations is revealed.

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