Estratérgias para dimensionamento de uma instalação piloto de um biorreator anaeróbio de fluxo ascendente

Abstract

The objective of this study was to elaborate and to develop strategies for the design of a pilot plant of an Upflow Anaerobic Sludge Blanket - UASB. In the design of UASB type reactors, mainly those that deal with effluent of low concentration, the sizing is made by the hydraulical load criterion, and not for the organic load. In this case, the ascending velocity in the decantation and digestion compartments starts to be of basic importance higher velocities result in the loss of biomass of the system, reducing the process stability. As consequence, the height of the reactor must be reduced, increasing its transversal section, in order to guarantee the maintenance the upward velocity of the adequate ranges. In for the project of an UASB pilot reactor, with didactic purposes, the functions of each component of the reactor had been studied, identifying to them the necessary fluid dynamic characteristics to the good performance of the set. Simple mathematical models are presented to guarantee ranges of upward and sedimentation velocities of the liquid and solid phases, respectively. For the gaseous phase important operational parameters had been identified, mainly in the stages of start-up and shutdown. As one of the consequences of the study a computational program of sizing for a pilot UASB is presented in Matlab® language. The program is simple, interactive and provides simulation of hydraulical parameters of the reactor. With aid of support tools as pilot unit and of simulation program, it can be made forecasts of an operation adjusted for UASB reactors in commercial scale