Diseño de una planta para la producción de pellets de biocarbón a partir de la torrefacción en atmósfera inerte de residuos de madera de balsa por lecho fluidizado.

Abstract

The present work had the purpose of carrying out the design of a biochar pellet production plant from the torrefaction of balsa wood residues by means of a fluidized bed. The production plant has an estimated annual pellet production capacity of 15 866,5 t distributed in 50 kg bags, the same amount that is achieved starting from 82,8 t/d of balsa wood waste. The selected location of the plant is the city of Guayaquil in the Guayas province, due to raw material availability, since a large number of balsa wood companies are located in that province. The defined production process for biochar pellets involves the following unit operations: grinding, screening and storage of raw material, wheat starch and finished product; nitrogen generation and heating, torrefaction, cyclone separation, cooling, mixing, pelletizing and bagging. Within these proposed unitary operations, torrefaction is the most relevant process since in that operation the thermochemical transformation of balsa wood residues is carried out, for which a Torbed-type fluidized bed reactor is used, in which gaseous nitrogen is fed, the same one that will be in charge of producing the fluidized bed and roasting the biomass at a temperature of 220 °C for 15 minutes. The pre-feasibility study was executed when the evaluation of the project was being carried on in a period of over 10 years, where it was possible to determine the net present value (NPV) and the internal rate of return (IRR), whose values are 3 414 216,43 USD and 50,78 % respectively, which allowed predicting that the capital recovery will take place in a period of 3 years, and therefore, it was found that the implementation of the biochar plant from balsa wood would be profitable and feasible.