Valorization of Leucaena leucocephala for energy and chemicals from autohydrolysis

Abstract

In this work, Leucaena leucocephala K366 was characterized chemical and energy terms, and assessed its potential as a lignocellulosic raw material and energetic and industrial crop specie, and its integral fractionation by autohydrolysis by evaluating its calorific value, holocellulose, glucan, xylan, araban, lignin and oligomers and monomers contents in autohydrolysis liquor and solid phase. Also, this paper will consider the influence of the temperature and time of autohydrolysis process from Leucaena leucocephala K366 to obtain a valuable liquor and a suitable solid phase to produce energy by combustion. A valuable liquor was obtained from the autohydrolysis of Leucaena leucocephala K366 by simultaneously using operating temperatures and times in the medium-high ranges studied, namely: 172--30 min. The optimum processing conditions provided an acceptable yield (16-26%), and high xylose and xylo-oligomer contents in the liquor (10.0 and 58.6%, respectively, of the amounts present in the starting raw mate fraction was extracted virtually completely ─only 8.3% remained in the solid fraction─, and the acetyl group fraction was recovered in full. In addition, these conditions reduced the glucose content of the liquor to 2.9% of the amount present in the raw material while largely preserving the integrity of cellulose fibers.Klason lignin was scarcely dissolved under the operating conditions of the auto¬hydrolysis process. This increased the calorific value of the solid phase by 9% (under the most drastic operating conditions) with respect to the starting raw material. AbstractIn this work, Leucaena leucocephala K366 was characterized chemical and energy terms, and assessed its potential as a lignocellulosic raw material and energetic and industrial crop specie, and its integral fractionation by autohydrolysis by evaluating its calorific value, holocellulose, glucan, xylan, araban, lignin and oligomers and monomers contents in autohydrolysis liquor and solid phase. Also, this paper will consider the influence of the temperature and time of autohydrolysis process fromLeucaena leucocephala K366 to obtain a valuable liquor and a suitable solid phase to produce energy by combustion.A valuable liquor was obtained from the autohydrolysis of Leucaena leucocephala K366 by simultaneously using operating temperatures and times in the medium-high ranges studied, namely:172-184 C and 15-30 min. The optimum processing conditions provided an acceptable yield (16-26%), and high xylose and xylo-oligomer contents in the liquor (10.0 and 58.6%, respectively, of the amounts present in the starting raw material when operating at 184 C for 30 min). The araban fraction was extracted virtually completely ─only 8.3% remained in the solid fraction─, and the acetyl group fraction was recovered in full. In addition, these conditions reduced the glucose content of the liquor to 2.9% of the amount present in the raw material while largely preserving the integrity of cellulose fibers.Klason lignin was scarcely dissolved under the o...

Leucaena leucocephala: an underutilized plant for pulp and paper production

“…The species is also used for pulp and paper production (Lopez et al 2008;Diaz et al 2007), wood production (Tewari et al 2004;Prasad et al 2011), green manuring (Sharma et al 1998;Sharma and Behera 2010), phytoremediation and revegetation of fly ash basins and other contaminated areas (Cheung et al 2000;Lins et al 2006), for prevention of slope failure (Normaniza et al 2008), for energy and chemicals from autohydrolysis (Feria et al 2011). L. leucocephala can also be used for soil erosion, for reclamation of marginal and degraded waste land (due to high nitrogen-fixing potential), as ornamental and to control air pollution along roadside, as live fence along cultivated fields and for shade and support for shade loving plants and vines such as pepper, vanilla, and yam etc.…”

“…Some recent articles provides knowledge and perspectives of Leucaena such as optimum stand density for wood production (Prasad et al 2011); changes in fiber length and some pulp chemical properties in different varieties (Diaz et al 2007), valorisation for energy and chemicals (Feria et al 2011), manipulation of lignin (Rastogi and Dwivedi 2008). However, there is scarcity about the commercial cultivation of Leucaena.…”

“…It is a neglected and underutilized; medium to small sized tree of multiple values. It has fast growing nature, easy adaptability to various ecological conditions but suitable for tropical conditions, high biomass productivity and re-sprouts capacity (more than 50 t ha -1 year -1 ) (Feria et al 2011). It is commonly known as horse tamarind, lead tree, leucaena, white lead-tree, white popinac, wild tamarind in English and koo babul, ku-babul, lamtoro, subabul in Hindi.…”

Optimization the soda-AQ process for cellulose pulp production and energy content of black liquor from L. leucocephala K360

“…The soil was sandy loamy with a pH of 6-8 at the experimental site and had moderate to substantial depths. The productivity of L. Leucocephala was 49.6 ± 10.67 ton/ha/yr of total dry weigh, and the harvested timber weighed 86 kg (Feria et al, 2011a), the Leucaena leucocephala samples were milled to pass an 8-cm screen, reduced to pieces between 2 and 10 mm in length by use in the reactor, and fines were removed by sieving through a 0.6-mm mesh. Samples were air-dried, homogenized by mixing, and stored at room temperature.…”

“…The gross heating value for L. leucocephala was slight lower than that of L. diversifolia (2.0%) (Feria et al, 2009) and other solid biofuels such as willow and one-year-old poplar (Klasnja et al, 2002), but higher than that of Populus euramericana or Eucalyptus globulus (between 18.8 MJ/kg and 17.0 MJ/kg) (Telmo et al, 2010). Table 4 shows Kappa number, viscosity and results from the physical characterization of paper sheets (brightness, tensile index, burst index and tear index).…”