Análise e simulação estacionária e dinâmica de um sistema de purificação de biogás

Abstract

The growing trend in the use of biogas in the global and national scenario, driven by the search for a better use of the potential of organic materials as fuel sources, highlighted the need for biogas purification processes, aiming at increasing its calorific value and reducing impurities to achieve the specifications of current regulatory standards. The present work has as objective the representation of a 14 Nm³/h biogas purification system of the company ER-BR Renewable Energies Ltd. through simulations in the commercial software Aspen Hysys® V.12 and evaluation of dynamic behaviors of the system. The purity of the final product obtained at steady state without recycle was 89.56% compared to the value of 89.00% measured experimentally. For the steady-state operation with water recycle, the required make-up water flow was 0.042 Nm³/h. The high methane losses observed under the simulated operating conditions (3.7 - 7.3%) indicate that the evaluation of new purification system configurations is recommended. Increasing the L/G ratio of biogas from 0.20 to approximately 0.22 resulted in a reduction in the molar fraction of CO2 in the final product from 9.1% (base case) to 5.2%. The molar composition of the simulated product for the operation without solvent recycle showed absolute deviations in the order of 10-2% in relation to the experimental data. Furthermore, the behavior of the system in relation to applied disturbances was consistent with the trends observed in studies in the literature, validating the simulations.