The influence of the process conditions of pulping of a trihybrid clone Paulownia on pulp properties for the soda anthraquinone process has been investigated in a semi-pilot scale. A composite central experimental design and a multiple regression were used to find the relationship between independent process variables and pulp properties. The ash content (0.89%) is lower and cellulose content (44.0%) is higher than those found for other species of Pauwlonia and other energetic crops. The elemental composition has a low content in S and N (0.21%) in comparation with poplar or willow. With a gross heating value of 20335 J/g, Paulownia is a suitable feedstock for use as solid biofuel. This is somewhat higher than those for hardwood, slightly higher than those for Pinus pinaster and softwood, and much higher than those for residues of food plants and agricultural crops. This supports the use of the genus Paulownia as an energy crop. The soda-anthraquinone pulping could be and adequate process for Paulownia. Fibre length (0.97 mm) is similar to hardwoods and suitable physical characteristics of paper sheets (tensile index) and acceptable chemical characteristics and yield pulping could be obtained by operating at lowintermediate temperature (163-171ºC) and alkali concentration (20%) and high or medium values for operation time (120-150 min). The pulp obtained at these conditions has suitable chemical (pulp) and physical (paper sheets) characteristics: yield (47.0%), ethanol-benzene extractives (2.22%), holocellulose contents (96.0%), α-cellulose contents (75.8%), lignin contents (8.28%), Shopper Riegler degree (23.2 ºSR), and tensile index (36.0) kN m/kg. HighlightsThe influences of the process conditions of pulping of a trihybrid clone Paulownia on pulp properties for the soda anthraquinone process have been investigated in a semi-pilot scale.The soda-anthraquinone pulping could be and adequate process for trihybrid clone Paulownia is similar to hardwoods and suitable physical characteristics of paper sheets.Trihybrid clone Paulownia is a suitable feedstock for use as solid biofuel.

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...

In this study we evaluated the potential of a species trihybrid fortunei Paulownia, tomentosa and elongata as an industrial crop in terms of its contents in holocellulose, lignin, xylo-oligomers, monomers and other glucan and its aprovecahamiento for making cellulose pulp. Well optimized biomass autohydrolysis processes yield valuable liquid and solid phases that can be used to produce liquid fuels and cellulosic pulp. This study focused on the optimization of autohydrolysis temperature and time during processing of Paulownia fortunei x Tormentose x Elongate hybrid wood.. The process was modelled in order to optimize the extraction of xylo-oligomers and xylose in the liquid phase while preserving the integrity of cellulose fibres. The optimum processing conditions (viz. temperatures of 180-195 °C and operating times of 0-15 min) provided an acceptable solid phase yield (70%), while maintaining a high xylose and xylo-oligomer contents in the liquid phase. Soda -anthraquinone pulping of solid fraction provide 60.6 % pulp yield at kappa number 33 and a viscosity of 787 cm 3 /g. The autohydrolysed chips required 16.6 % less alkali than the regular chips to achieve kappa number 33.Keywords: Autohydrolysis, biorefinery, paulownia, soda-AQ pulp, saccharides. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 F o r P e e r R e v i e w 3 Page 2 of 22 John Wiley & Sons 2t-S-1Ed-D-P INTRODUCTIONThe current European social development concerning the use of natural resources is not sustainable since it is largely based on fossil fuels, which are non-renewable and release large quantiteis of CO 2 to the atmosphere. There is a shortage of renewable raw materials in the market to attend the energy, pulp & paper and chemical industry sectors. The way to a sustainable development and resource renewability includes the searching/use of new resources and chemical and consumption products with which the lignocellulose forest biomass, and specially that one of high production of biomass capacity (energetic crops), shows as a "necessary" source of raw material due to its ubiquity, availability and "low pollutant character" [1,2]. Biomass components fractionation would also allow the disposal of a variety of chemical products, for which technological development requires the integration of all stages, from farming and harvesting to the stages of fractioning and conversion to different products [3].Paulownia crops present very high productions of biomass and re-sprouting capacity (more than 50 tons/ha/year, specially in annual crops, which are among the highest growing levels described in the literature [4].Paulownia is one of these crops with very high productions of biomass and re-sprout capacity (more than 50 tons/ha/year, specially in annual crops, which are among the highest growing levels described in the bibliography [5]. Paulownia is a specie us...

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The aim of this study was to optimize the production of furfural by hydrolysis with dilute acid of Eucalyptus globulus wood in two stages, using a factorial experimental design and multiple regression models to maximize furfural yields. The two-stage process could provide a solid phase with less degraded cellulose and older applications that the solid phase of a conventional acid hydrolysis. The selectivity for furfural of the process was increased by effect of the glucan and lignin fractions being efficiently removed after the first acid hydrolysis stage.The operational ranges are especially suitable for the extraction of xylose, which was virtually quantitative at 170 ºC and virtually independent of the operation time. It is therefore advisable to use non-isothermal conditions or short times. This is quite important if one considers the low acid concentration used. The liquid phase obtained after autohydrolysis of the raw material under the optimum conditions contained 2.3% glucose, 9.8% xylose, 2.5% xylo-oligomers, 0.6% arabinose, 1.1% furfural and 0.1% 5-OH methyl furfural.After the residual solid from the first hydrolysis stage is removed, the acid concentration is the most influential variable on the conversion of xylo-oligomers or xylose into furfural. Conversions to furfural were quite substantial (greater than 10 g/L). Hemicelluloses in the raw material were extracted by 32-57.7% and xylan by 40.5-84%. The highest conversions to furfural were obtained by using a medium operation time (15 min) and low temperature (170 ºC) and pH=2.The process additionally provides hemicellulose derivatives that are scarcely contaminated with cellulose derivatives. The concentrations of gluco-oligomers were very low and those of glucose in the region of 3% of the raw material.Response to Reviewers: Optimization of furfural production by acid hydrolysis of Eucalyptus globulus in two stages. Ms. Ref. No.: CEJ-D-13-02942 LIST OF CHANGES Reviewers' comments:REVIEWER 1: The manuscript dealed with the furfural production from woody biomass. If the manuscript just focused on the optimization of two stage of furfural production, the novelty seems not enough. The authors were suggested to provide some evidences for advantages of two stage process as compared with single stage. In many parts, the writing hard to be understood. RESPONSE TO REVIEWER COMMENT:(*) The use of lignocellulosic biomass as a sustainable, renewable raw material for the production of chemicals and energy is steadily gaining interest. Despite the difficulties, especially as regards the need to fractionate its components in order to make the process cost-effective, there is increasing experimental evidence of its viability. For example, research has shown the possibility of obtaining ethanol as main product, but also that other structural components such as hemicelluloses and polyphenols (lignin) can be useful to obtain foods, pharmaceuticals, plastics, paper and basic chemicals, among others, by using a series of process known as "Biorefining". An ...