HTST hydrolysis of wood: Modelling of the kinetics and projections on reactor configuration     

J. L. Madelaine  J. M. Bouvier  M. Gelus 《Wood Science and Technology》1990,24(2):143-157

Summary We present experimental data on hydrolysis of wood in high temperature short residence time (HTST) and low acid concentration conditions. Effects of temperature, acid concentration, particle size and liquid/solid ratio are discussed. A kinetic model is proposed which accounts for effects of temperature and acid concentration. This kinetic model is used to predict performance of a twin-screw extruder as a hydrolyser which consists of ideal mixed flow or plug flow reactor units in series.Symbols A Acid concentration in liquid phase - A Acid concentration in solid phase - A₀ Initial mass of sulphuric acid, g - C Cellulose content of solid phase, % - d Diameter of wood particles, m - E₁ Activation energy of cellulose hydrolysis, cal. mol^-1 - E₂ Activation energy of glucose degradation, cal. mol^-1 - F Objective function, refers to Eq. (5) - G Glucose yield - G_e Glucose yield at equilibrium - G_{i, exp} Experimental glucose yield (Eq. (5)) - G_{i, th} Calculated glucose yield (Eq. (5)) - G_max Maximum glucose yield - k^* Parameter defined by Eq. (9) - k₁ Rate constant of cellulose hydrolysis, s^-1 - k₂ Rate constant of glucose degradation, s^-1 - k ₁ ^* Apparent rate constant of cellulose hydrolysis, s^-1 - k ₂ ^* Apparent rate constant of glucose degradation, s^-1 - k₁₀ Pre-exponential factor of constant k₁, s^-1 - k₂₀ Pre-exponential factor of constant k₂, s^-1 - K Parameter defined in Table 3 - m Constant - m_g Mass of glucose produced, g - M₀ Initial mass of wood, g - M Mass of saturated steam delivered, g - M Mass of saturated steam delivered after 120 s of reaction time, g - m₀ Initial mass of water, g - n Constant - N Number of reactor units - q_i Volume flow rate in reactor units, m³ · s^-1 - r_g Conversion rate of glucose, s^-1 - R Ideal gas constant, 1.987 cal · mol^-1 K^-1 - t Reaction time, s - T Temperature, K - V_i Volume of reactor units, m³ - W Water content of wood sample, % - X, X Parameters defined in Table 3 - Y, Z Parameters defined in Table 3 - Constant defined in Eq. (4), s^-1 - v Number of experimental points (Eq. (5)) - _i Residence time in plug flow unit, s - _i Residence time in mixed flow unit, s  相似文献   

Antibiosis of Eucalyptus plants on Podisus nigrispinus     

Anderson Mathias Holtz  Angelo Pallini  Madelaine Venzon  José Cola Zanuncio  Dirceu Pratissoli  Wagner Faria Barbosa  Gilberto Santos Andrade 《Phytoparasitica》2010,38(2):133-139

The predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) has been used as a natural enemy to control herbivorous insects in eucalyptus plantations. However, because of the short co-evolutionary history of the predator with this imported plant species, the defensive compounds of eucalyptus may have a negative effect on the predator. Therefore, the survival and development of P. nigrispinus were studied on eucalyptus (Eucalyptus urophylla; exotic host plant) and guava (Psidium guajava; native host plant). P. nigrispinus performance was indeed superior on guava plants than on eucalyptus. The number of fertile eggs and nymphal survival were 52.6% and 12.0% on guava compared with 20.0% and 1.3% on eucalyptus, respectively. Longevity of P. nigrispinus was 115 days on guava and 98 days on eucalyptus. This shows that the predator is not yet fully adapted to the exotic host plant. One possible reason is that the plant toxic compounds in eucalyptus act on this predator by antibiosis.  相似文献   

New methods for aerosol size distribution determination with a diffusion battery     

J. P. Maigne  G. Madelaine  P. -Y. Turpin  J. Bricard 《Water, air, and soil pollution》1974,3(4):527-535

The method of precipitation of granules on the walls of narrow flow tubes furnishes data that are dependent on both the grain size and the particle abundance. The objective desired is to determine both of these quantities from the observations. The paper presents an analytic method for doing so. It is tested on a uranine aerosol, and the results are found to compare favorably with electron microscope studies of the same aerosol.  相似文献   

Effects of lime sulfur on Neoseiulus californicus and Phytoseiulus macropilis,two naturally occurring enemies of the two‐spotted spider mite Tetranychus urticae     

Henry E Vacacela Ajila  Eugênio E Oliveira  Felipe Lemos  Khalid Haddi  Felipe Colares  Pedro H Marques Gonalves  Madelaine Venzon  Angelo Pallini 《Pest management science》2020,76(3):996-1003

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