摘要 |
A process to obtain low molecular weight polyphenols, medium molecular weight polyphenols, and a standardized solid fuel from tree bark or wood that includes the stages of: bark grinding; solid-liquid extraction from the bark using a low molecular weight aliphatic; concentration of the extract, to recover the aliphatic alcohol used in the extraction; decantation, filtration and/or centrifugation, in order to separate the solid and liquid phases of the extract; drying of the soluble fraction in water of the hydroalcoholic extract; drying of the insoluble fraction in water; separation of the fine fraction of the bark extracted in a sieve and/or air fractionation system. Also revealed are the use of the soluble fraction in water of the hydroalcoholic fraction as a raw material to prepare thermohardening resins, using aldehydes and/or isocianates as cross-linking agents, the use of the insoluble fraction in water of the hydroalcoholic extracts as a raw material for processes of extrusion, injection or another process of transformation, characteristic of the plastics industry, and the use of bark free of extracts, directly as a solid fuel in industrial and/or residential combustion equipment or subjected to a densification process, to produce pellets, briquettes or another solid densified fuel. |