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Anaerobic digestion has been widely applied for waste treatment, renewable energy generation , biofertilizer production. The biogas potential in Brazil is sizable, but the state of Rio de Janeiro is largely dependent on fossil fuels , there is a lack of biogas potential assessments in the state. Thus, this study evaluated biomethane, electricity and biofertilizer potentials in the region. Three different scenarios of biomass supply were considered for four major biowaste streams: sewage sludge; cattle manure; sugarcane processing waste; and food waste. Biomethane generation from the assessed sources could reach 0.6-1.3 billion Nm(3) year(-1), corresponding to 1,768-3,961 GWh year(-1) of electricity , 1.6-3.3 million Mg year- 1 of biofertilizer. Cattle manure was responsible for 73-84% of the projected biomethane production, presenting an opportunity to reduce the sig-nificant emissions from livestock farming. The estimated biofertilizer production could meet the demands of the state , the produced electricity could offset up to 10% of the demand. The gas grid could facilitate the dis-tribution of upgraded biomethane, and 10-22% of the natural gas demand could be met. The findings of this work highlight the high potential for biogas generation in Rio de Janeiro, which is up to seven times larger than the current production., Funding Agencies|Graduate Program in Biological Sciences (Neotropical Biodiversity) -PPGBIO at Universidade Federal do Estado do Rio de Janeiro (UNIRIO); Vinnova [2019-05382]; Swedish Energy Agency [35624-2]; Formas [2021-02429]; Brazilian National Council for Scientific and Tech- nological Development (CNPq); Biogas Research Solution Center; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ)

This paper presents a numerical approach to a model describing the pattern formation by ion beam sputtering on a material surface. This process is responsible for the appearance of unexpectedly organized patterns, such as ripples, nanodots and hexagonal arrays of nanoholes. A numerical analysis of preexisting patterns is proposed to investigate surface dynamics, based on a model derived from a anisotropic damped Kuramoto-Sivashinsky equation, in a two dimensional surface with periodic boundary conditions. While deterministic, its highly nonlinear character gives a rich range of results, making it possible to describe accurately different patterns. A finite-difference semi-implicit splitting scheme is employed on the discretization of the governing equation. Simulations were conducted with realistic coefficients related to physical parameters (anisotropies, beam orientation, diffusion). The stability of the numerical scheme is verified with time step and grid spacing tests for the pattern evolution. Hexagonal patterns were obtained from a monomodal initial condition for a higher value of the damping coefficient, while spatiotemporal chaos appeared for lower values. The hexagonal ordered character of the structure was shown to be directly proportional to the damping coefficient.