Optimal conditions for hemicelluloses extraction from Eucalyptus globulus wood: hydrothermal treatment in a semi-continuous reactor

Abstract

Optimal conditions for hemicellulose extraction from wooden biomass in a semi-continuous system have been assessed in this work. This study would constitute the first stage for a profitable and green industrial process. Eucalyptus globulus was selected as raw material due to its low water consumption, high growth and its efficiency in lignocellulose production. Moreover its cultivation is very popular in southern Europe. Samples of 5.0 g of wood were fractioned using a pressurized hot water semicontinuous system, to produce sugars (pentoses and hexoses) and a solid residue enriched in lignin.Five flow rates between 2.50 and 20.00 mL/min and four temperatures between 135.0 and 285.0 ºC were tested in order to maximize the production of sugars, avoiding the formation of degradation products.Optimum conditions for the extraction of hemicellulose were identified at 185.0 ºC and 5.00 mL/min, leading to a pentoses yield of 67.409 wt%, with 0.702 wt% of degradation products. Almost all the pulp is extracted at 285.0 ºC. SEM images show very well the changes in the wood structure at different temperatures.A kinetic model was developed, describing the extraction and hydrolysis of hemicellulose and cellulose with absolute average deviations around 10 % for sugar extracted mass.

Intrinsic dissolution kinetics and topochemistry of xylan, mannan, and lignin during auto‐hydrolysis of red maple wood meal

“…Previous autohydrolysis research was mostly carried out in batch and flow‐through reactors. Examples of dissolution kinetics obtained for hardwood batch autohydrolysis studies have been performed by Garrote et al, Jacobsen and Wyman, Mittal et al, Tunc and van Heiningen, and Borrega et al Similar through‐flow studies are shown by Kilpelainen et al, Borrega and Sixta, and Gallina et al However, batch reactors are not best suited to study the intrinsic dissolution kinetics of the different wood components because they degrade further in the bulk of the solution. This problem is overcome in a tubular flow‐through reactor when the liquid residence time is relatively short so that the dissolved components are quickly removed from the high temperature system.…”

Making Levulinic Acid and Ethyl Levulinate Economically Viable: A Worldwide Technoeconomic and Environmental Assessment of Possible Routes

“…[c] corn stover0.465 [148] 0.337 [149] 0.2050.228 0.087 0.143 12.61 [150] 25 cotton straw 0.498 [88] 0.426 [88] 0.2710 .182 0.041 0.080 15.62 [150] 25 EFB 0.455 [151] 0.383 [143] 0.3530 .221 0.016 0.027 14.54 [85] 25 energy cane bagasse 0.467 [151] 0.433 [152] 0.2380 .217 0.008 0.104 10.01 [153] 50 eucalyptus wood 0.529 [154] 0.425 [155] 0.2290 .275 0.002 0.069 12.56 [156] 25 giant reed 0.471 [157] 0.311 [158] 0.3530 .185 0.061 0.090 12.52 [159] 25 giant miscanthus0.484 [160] 0.504 [161] 0.2480 .120 0.027 0.101 12.46 [162] 25 oat hulls 0.460 [154] 0.363 [163] 0.3850 .058 0.054 0.140 12.14 [164] 25 OPF 0.480 [160] 0.304 [143] 0.4040 .217 0.058 0.017 11.12 [165] 25 paper sludge0.490 [166] 0.491 [167] 0.1710 .194 0.102 0.042 7.479 [160] 50 pinewood 0.494 [154] 0.537 [168] 0.0640 .324 0.029 0.046 12.77 [169] 25 rapeseed residue 0.445 [170] 0.440 [171] 0.1780 .192 0.130 0.060 10.01 [160] 50 rice husks 0.388 [157] 0.310 [172] 0.2430 .143 0.217 0.087 12.75 [173] 25 rice straw 0.382 [157] 0.342 [174] 0.2130 .267 0.115 0.063 13.84…”

Development of an integrated and green biorefinery from winery waste. Application to wine lees and grape stems

“…As a whole, it can be observed that grape stems seemed to have a completely different behaviour if compared with other woody biomasses since higher sugars yield were expected at a temperature of 180ºC (Cocero et al, 2018a). Nevertheless, the extraction yield respect to the biomass able to be recovered was similar to the reported by other authors in literature (67 vs 60%, respectively) (Gallina, Cabeza, Biasi, & García-Serna, 2016;Yedro et al, 2017).…”