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Pulp Suspensions (pulp + suspension)
Selected AbstractsBioethanol production from bio- organosolv pulps of Pinus radiata and Acacia dealbataJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 8 2007Claudio Muñoz Abstract Wood chips from Pinus radiata and Acacia dealbata were pretreated with the white-rot fungi Ceriporiopsis subvermispora and Ganoderma australe, respectively, for 30 days at 27 °C and 55% relative humidity, followed by an organosolv delignification with 60% ethanol solution at 200 °C for 1 h to produce pulps with high cellulose and low lignin content. Biotreatment for 30 days was chosen based on low weight and cellulose losses (lower than 4%) and lignin degradation higher than 9%. After organosolv delignification, pulp yield for P. radiata and A. dealbata pulps was 45,49% and 31,51%, respectively. P. radiata bio-pulps showed higher glucan (93%) and lower lignin content (6%) than control pulps (82% glucan and 13% lignin). A. dealbata bio-pulps also showed higher glucan (95%) and lower lignin content (2%) than control pulps (92% glucan and 4% lignin). Pulp suspensions at 2% consistency were submitted either to separate enzymatic hydrolysis and fermentation (SHF) or simultaneous enzymatic saccharification and fermentation (SSF) for bioethanol production. The yeast Saccharomyces cerevisiae was used for fermentation. Glucan-to-glucose conversion in the enzymatic hydrolysis of control and bio-pulps of P. radiata was 55% and 100%, respectively, and it was 100% for all pulp samples case of A. dealbata. The highest ethanol yield (calculated as percentage of theoretical yield) during SHF of P. radiata control and bio-pulps was 38% and 55%, respectively, and for A. dealbata control and bio-pulps 62% and 69%, respectively. The SSF of P. radiata control and bio-pulps yielded 10% and 65% of ethanol, respectively, and 77% and 82% for A. dealbata control and bio-pulps, respectively. In wood basis, the maximum conversion obtained (g ethanol per kg wood) in SHF was 37% and 51% (for P. radiata and A. dealbata pulps, respectively) and 44% and 65% in SSF (for P. radiata and A. dealbata pulps, respectively) regarding the theoretical yield. The low wood-to-ethanol conversion was associated with low pulp yield (A. dealbata pulps), high residual lignin amount (P. radiata pulps) and the low pulp consistency (2%) used for SHF and SSF. Copyright © 2007 Society of Chemical Industry [source] Soft measurement of pulp suspension flow velocity based on wavelet transformTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 1 2010Qiang Zhou Abstract A soft measurement technique is presented, which the pulp suspension flow velocity (PSFV) can be obtained by analysis of pulp fibre consistency signal without using the flow sensor or flow meter. Doppler Effect in pulp fibre consistency signal, which is caused by the relative motion between pulp suspension flowing in pulp pipe and consistency sensor fixed in the pipe, is discovered on the basis of studying the structure of pulp suspension and the properties of pulp fibre consistency signal, and it is proved by wavelet transform (WT) in this paper. WT are used to analyse pulp fibre consistency signal based on Doppler Effect. PSFV can be determined by the average period of WT which is used to analyse pulp fibre consistency signal based on Doppler Effect. The corresponding tests indicate that the measurement technique is feasible with high precision and better dynamic characteristics. Une technique de mesurage douce est présentée selon laquelle la vélocité de débit de suspension de pâte (pulp suspension flow velocity - PSFV) peut être obtenue par analyse du signal de la consistance de la pâte sans faire appel à des détecteurs de débit ou à des débitmètres. L'effet Doppler dans le signal de consistance de la pâte, causé par le mouvement relatif entre la pâte en suspension s'écoulant dans la conduite de pâte et le senseur de consistance fixé dans la conduite, a été découvert en se basant sur l'étude de la structure de la pâte en suspension et les propriétés du signal de consistance de la pâte et il est prouvé par transformation d'ondelettes. La masse atomique est utilisée pour analyser le signal de consistance de la pâte basée sur l'effet Dopler. Le PSFV peut être déterminé par la période moyenne de la masse atomique utilisée pour analyser la consistance de la fibre de la pâte s'appuyant sur l'effet Dopler. Les essais correspondants indiquent que la technique de mesurage est réalisable avec grande précision et de meilleures caractéristiques dynamiques. [source] RHEOLOGICAL PROPERTIES OF NONCOHESIVE APPLE DISPERSION WITH HELICAL AND VANE IMPELLERS: EFFECT OF CONCENTRATION AND PARTICLE SIZEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2000DENIS CANTÚ-LOZANO ABSTRACT The proportionality constant, ks, between shear rate, ,, and agitation velocity, N, for a helical ribbon-screw (HRS) agitator was 17.8. Using the HRS agitator, values of consistency index K and the flow behavior index n of 14 apple pulp suspensions at seven different solids concentrations and two average particle diameters 0.71 mm and 1.21 mm were determined; in addition, values of the Casson viscosity ,c and yield stress ,OC were also calculated. The magnitudes of K increased and of n decreased with increase in pulp concentration. Experimental values of the vane yield stress, ,O,, measured with a six-blade vane increased with increase in pulp content. The values of ,OC obtained using the Casson model were close to the experimental values ,O,. The effect of particle size on the relative viscosity, ,r, was correlated with Peclet number. [source] Near Wall Studies of Pulp Suspension Flow Using LDATHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 4 2006A. Johan Pettersson Abstract A detailed study of the flow behaviour in the near wall region of pulp suspensions up to 4.7% have been performed using Laser Doppler Anemometry (LDA) in pipe flow. Axial mean velocity profiles show a distinct plug flow and an increase of the plug region as the flow rate decreases and fibre concentration increases. An attempt is made to relate the LDA data-rate to fibre concentration, which indicates a dilution region at 1-2 mm from the wall that is larger than the annulus region. The dilution region increases with increasing flow rate, decreasing concentration and when using longer pulp fibres. On a réalisé une étude détaillée du comportement d'un écoulement dans la région proche de la paroi de suspensions de pâte jusqu'à 4,7 %, en utilisant l'anémométrie laser Doppler (LDA) dans une conduite. Les profils de vitesse axiale moyens montrent un écoulement piston distinct et une augmentation de la région piston lorsque le débit diminue et la concentration de fibres augmente. Une tentative est faite pour relier les données de vitesse LDA à la concentration de fibres, qui indique une région de dilution à 1-2 mm de la paroi plus grande que l'espace annulaire. La région de dilution augmente avec l'augmentation du débit, la diminution de la concentration et l'utilisation de fibres de pâtes plus longues. [source] | ||||||||||