PYROLYSIS OF LIGNIN BIOMASS NOVOLAC RESIN FOR THE PRODUCTION OF POLYMERIC CARBON ADSORBENTS

Carbonaceous adsorbents, based on Klason lignin isolated from olive stone biomass and novolac resin, were prepared. Four groups of materials were used as raw materials and were then cured, pyrolyzed (in an N2 stream up to 1000-degrees-C) and in some cases activated (with a water vapour at 930-degrees-C): (1) Klason lignin hydroxymethylated and phenolated (KLHP); (2) Klason lignin hydroxymethylated and phenolated combined with pressed olive stones (KLHP-OS); (3) Klason lignin hydroxymethylated and phenolated combined with novolac resin (KLHP-N); (4) 93% w/w of novolac prepared in presence of 7% wt/wt of Klason lignin (N-KL) and then mixed with pressed olive stones (N-KL-OS). The weight losses and shrinkages of raw materials during pyrolysis, the FT-IR spectra of raw materials and of end-products, and the specific surface area of end-products and their discolouring ability using aqueous solution of methylene blue, were determined. The combination of such materials can improve the characteristics of end-products (e.g. higher specific surface area and discolouring ability) or the processing characteristics (e.g. lower weight losses and shrinkages of materials during pyrolysis). Also, the participation of lignin in reactions with phenol was determined. Such materials, especially KLHP-N with an excess of novolac and secondarily KLHP-OS with an excess of olive stones, show interesting potential as raw materials for the production of polymeric carbon adsorbents.