Assessment of lignocellulosic materials quality and furfural production from corn cobs, sugarcane bagasse, eucalyptus wood and dissolving pulp pre-hydrolizate

Abstract

This work is presented in two distinct parts, the first focused on the quality of eucalyptus wood grown for pulp production under different ferti-irrigation systems (Chapter 1) and the second on the preliminary assessment of the quality of eucalyptus wood and other materials for the production of furfural such as sugarcane bagasse, corn cobs and pre- hydrolyzed eucalyptus from the pre-hydrolysis Kraft process for dissolving pulp production (Chapter 2). The great interest in eucalyptus wood comes from its low cost of production in some regions, mainly due to high forest productivity. Genetic improvements associated with appropriate forest management (fertilization, irrigation, etc.) stand out as important tools in the production of wood of high quality and low cost. The goal of Chapter 1 was to evaluate the effect of the ferti-irrigation regime on the chemical composition and specific basic mass of wood from clones of the Eucalyptus spp. and possible consequences on the production of cellulose pulp. Four clones were evaluated, two being from the species Eucalyptus grandis and the other two coming from hybrids of Eucalyptus grandis x Eucalyptus urophylla, with age of 72 months. The treatments were evaluated with two levels of fertilization, the Traditional no irrigated (T/NI) and Ferti-irrigation (F/I), and a treatment Control no irrigated (C/NI), which was to not use any fertilizer or irrigation, with each treatment having three replicates, totaling 36 samples. The results indicated statistically significant differences for specific basic mass , manganese, lignin syringyl/guaiacyl ratio and acetyl group content of the woods, and similarity in carbohydrate, total lignin, uronic acids, extractives, ash, Fe, Ca and Mg. We conclude that the technique of ferti-irrigation presented some negative aspects regarding the quality of the wood of certain eucalyptus clones, it being relevant to consider their impacts on the production process for manufacturing cellulose pulp. In Chapter 2, considering the biorefinery concept it is possible to integrate the processes of pulp production to those of materials, chemicals and fuels from lignocellulosic biomass. For example, furan derivatives, such as 5-hydroxymethylfurfural (HMF) and furfural originating from biomass have the potential to replace petroleum in the manufacture of fine chemicals and plastics. The effect was studied of different concentrations (1.5 to 5.2 mol.L -1 ) of mineral acids, hydrochloric acid (HCl), sulfuric acid (H 2 SO 4 ), and phosphoric acid (H 3 PO 4 ) on theproduction of furfural by hydro distillation of corn cob, sugarcane bagasse and eucalyptus wood. The liquor from the pre-hydrolysis Kraft process for dissolving pulp production was also assessed for furfural production, using sulfuric acid and hydrochloric acid as catalysts. The results showed that the production of furfural was strongly influenced by the concentration and type of mineral acid and the raw material. The highest productivity of furfural, based on the dry weight biomass were 30.2% for corn cobs and 25.8% for the sugarcane bagasse, both using HCl 5.2 mol.L -1 , for eucalyptus wood, the yield was 13.9% using 3.9 mol.L -1 HCl. The yield of conversion of pentose to furfural using the eucalyptus pre- hydrolysis liquor was 71.5% using HCl 3.9 mol.L -1 . It was concluded that using mineral acids as catalysts for hydro distillation is suitable for the production of furfural from lignocellulosic wastes originating from industrial processes.