Carbonização sustentável para valorização do bambu Bambusa tuldoide: produção de carvão ativado e caracterização do bio-óleo recuperado

Abstract

Biomasses are renewable energy sources that have been recognized as sustainable energy resources and alternatives to fossil fuels, as they have vast availability and variety. Bamboo, biomass of forest origin that grows naturally in tropical regions, is one of the biomass alternatives that has great potential, due to its high growth rate when compared to other types of biomass. One of the applications of bamboo is slow pyrolysis or carbonization, which is defined as the thermal degradation of any organic material in the total or partial absence of oxygen, whose main objective is the production of charcoal (solid fraction), with bio-oil and non-condensable gases as by-products. The charcoal produced by slow pyrolysis is used in various activities of our daily lives, whether in homes for preparing a barbecue, in the pharmaceutical industry, in the production of activated carbon, in the chemical industry as a source of carbon, graphite, filters and especially in industries steel mills. In this context, the objective of the present work was the production of charcoal via slow pyrolysis using bamboo of the Bambusa Tuldoide species as biomass using three carbonization finishers and three different kiln heating rates. Subsequently, the produced coal was subjected to chemical activation with zinc chloride as a chemical activation reagent. Then the specific area of the supplied activated carbon. Coal and bio-oil are used in the slow pyrolysis stage and activated carbon was characterized. The heating rate and the final carbonization temperature were evaluated through a factorial design ( ), which, after statistical treatment of the data provided empirical correlations, must predict the behavior of the studied process. The gravimetric yield of charcoal for the experiments varied from 36.62 to 47.02% and the fixed carbon content varied from 59.99 to 74.54%. The results induced by coal from carbonization show homogeneous results in terms of physical and chemical aspects, although they have a high content that prevents the ash used in the steel industry and a lot of low surface area, which indicates the need for the activation process. The activation procedure presents a production of approximately 60% (mass of activated carbon / mass of coal) for all tests performed, showing a trend in terms of yield. After the activation process, there was a significant increase in surface area when compared to coal before activation, reaching up to 849.99 m2 / g. Activated carbon was classified as a structure mainly of microspores (<2nm) which guaranteed the coal, together with a high surface area, high capacity for an adsorption operation. The bio-oil produced in carbonization was altered and presented a brown color, characteristic odor, pH around 3 and average water content close to 50%. The bio-oils collected by the slow carbonization of bamboo become a complex mixture located by a wide variety of organic compounds, which are mostly carboxylic acids and phenols (around 50.00 and 15.00% of the peak chromatographic area, respectively).