[en] Renewable energy sources are becoming more and more important for energetic demand management across the world. The EU directive 2001/77/CE, indicated that the organic fraction of the municipal solid waste has a biogenic origin and so it can be assimilate to a biomass. Therefore the recovery of this fraction for energy production became important from both environmental (Kyoto Protocol) and economic point of view (green certificates). This paper propose a model to revamp MBT plants (two fluxes) to recover the organic fraction of MSW (OFMSW) that, at present, is converted into CO₂ and into low-quality compost which is finally disposed of in landfills. Here we propose that bio drying replaces bio stabilization allowing OFMSW to be used to produce energy

[en] Diffusion-limited reactions are commonly found in biochemical processes such as enzyme catalysis, colloid and protein aggregation and binding between different macromolecules in cells. Usually, such reactions are modeled within the Smoluchowski framework by considering purely diffusive boundary problems. However, inertial effects are not always negligible in real biological or physical media on typical observation time frames. This is all the more so for non-bulk phenomena involving physical boundaries, that introduce additional time and space constraints. In this paper, we present and test a novel numerical scheme, based on event-driven Brownian dynamics, that allows us to explore a wide range of velocity relaxation times, from the purely diffusive case to the underdamped regime. We show that our algorithm perfectly reproduces the solution of the Fokker-Planck problem with absorbing boundary conditions in all the regimes considered and is thus a good tool for studying diffusion-guided reactions in complex biological environments.

[en] In the real world, diffusion-limited reactions in chemistry and biology mostly occur in crowded environments, such as macromolecular complex formation in the cell. Despite the paramount importance of such phenomena, theoretical approaches still mainly rely on the Smoluchowski theory, only valid in the infinite dilution limit. In this paper we introduce a novel theoretical framework to describe the encounter rate and the stationary density profiles for encounters between an immobilized target and a fluid of interacting spherical particles, valid in the local density approximation. A comparison with numerical simulations performed for a fluid of hard spheres and square well attractive hard spheres confirms the accuracy of our treatment. (paper)