scholarly journals Polysaccharides Release in a Laboratory-Scale Batch Hydrothermal Pretreatment of Wheat Straw under Rigorous Isothermal Operation

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 26
Author(s):  
Felicia Rodríguez ◽  
Efrén Aguilar-Garnica ◽  
Adrián Santiago-Toribio ◽  
Arturo Sánchez
Keyword(s):  
Wheat Straw ◽  
Temperature Control ◽  
Scale Up ◽  
Hydrothermal Pretreatment ◽  
Laboratory Scale ◽  
Reaction Stage ◽  
Isothermal Conditions ◽  
Heating And Cooling ◽  
Reliable Source ◽  
Isothermal Operation

Hydrothermal pretreatment (HP) is an eco-friendly process for deconstructing lignocellulosic biomass (LCB) that plays a key role in ensuring the profitability of producing biofuels or bioproducts in a biorefinery. At the laboratory scale, HP is usually carried out under non-isothermal regimes with poor temperature control. In contrast, HP is usually carried out under isothermal conditions at the commercial scale. Consequently, significant discrepancies in the values of polysaccharide releases are found in the literature. Therefore, laboratory-scale HP data are not trustworthy if scale-up or retrofitting of HP at larger scales is required. This contribution presents the results of laboratory-scale batch HP for wheat straw in terms of xylan and glucan release that were obtained with rigorous temperature control under isothermal conditions during the reaction stage. The heating and cooling stages were carried out with fast rates (43 and −40 °C/min, respectively), minimizing non-isothermal reaction periods. Therefore, the polysaccharide release results can be associated exclusively with the isothermic reaction stage and can be considered as a reliable source of information for HP at commercial scales. The highest amount of xylan release was 4.8 g/L or 43% obtained at 180 °C and 20 min, while the glucan release exhibited a maximum of 1.2 g/L or 5.5%. at 160 °C/180 °C and 30 min.

Pressure drop, mechanic deformation, stabilization and scale-up of wheat straw fixed-beds during hydrothermal pretreatment: Experiments and modeling

2019 ◽  
Vol 360 ◽  
pp. 1587-1600 ◽  
Author(s):  
Wienke Reynolds ◽  
Marc Conrad ◽  
Sarah Mbeukem ◽  
Rainer Stank ◽  
Irina Smirnova
Keyword(s):  
Pressure Drop ◽  
Wheat Straw ◽  
Scale Up ◽  
Hydrothermal Pretreatment ◽  
Fixed Beds

scholarly journals Hydrothermal Pretreatment of Wheat Straw: Effects of Temperature and Acidity on Byproduct Formation and Inhibition of Enzymatic Hydrolysis and Ethanolic Fermentation

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 487
Author(s):  
Dimitrios Ilanidis ◽  
Stefan Stagge ◽  
Leif J. Jönsson ◽  
Carlos Martín
Keyword(s):  
Mass Spectrometry ◽  
Sulfuric Acid ◽  
Wheat Straw ◽  
High Performance ◽  
Enzymatic Saccharification ◽  
Hydrothermal Pretreatment ◽  
Gas Chromatography Mass Spectrometry ◽  
Enzymatic Digestibility ◽  
Acid Catalyzed ◽  
Pretreatment Conditions

Biochemical conversion of wheat straw was investigated using hydrothermal pretreatment, enzymatic saccharification, and microbial fermentation. Pretreatment conditions that were compared included autocatalyzed hydrothermal pretreatment at 160, 175, 190, and 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment at 160 and 190 °C. The effects of using different pretreatment conditions were investigated with regard to (i) chemical composition and enzymatic digestibility of pretreated solids, (ii) carbohydrate composition of pretreatment liquids, (iii) inhibitory byproducts in pretreatment liquids, (iv) furfural in condensates, and (v) fermentability using yeast. The methods used included two-step analytical acid hydrolysis combined with high-performance anion-exchange chromatography (HPAEC), HPLC, ultra-high performance liquid chromatography-electrospray ionization-triple quadrupole-mass spectrometry (UHPLC-ESI-QqQ-MS), and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Lignin recoveries in the range of 108–119% for autocatalyzed hydrothermal pretreatment at 205 °C and sulfuric-acid-catalyzed hydrothermal pretreatment were attributed to pseudolignin formation. Xylose concentration in the pretreatment liquid increased with temperature up to 190 °C and then decreased. Enzymatic digestibility was correlated with the removal of hemicelluloses, which was almost quantitative for the autocatalyzed hydrothermal pretreatment at 205 °C. Except for the pretreatment liquid from the autocatalyzed hydrothermal pretreatment at 205 °C, the inhibitory effects on Saccharomyces cerevisiae yeast were low. The highest combined yield of glucose and xylose was achieved for autocatalyzed hydrothermal pretreatment at 190 °C and the subsequent enzymatic saccharification that resulted in approximately 480 kg/ton (dry weight) raw wheat straw.

scholarly journals An Improved Process for the Preparation of the p-tert-butylcalix[4]arene: from Laboratory-scale Synthesis to Scale-up Development

2016 ◽  
Vol 3 (2) ◽  
pp. 134-146
Author(s):  
A. A. Fatyanova ◽  
A. S. Gusak ◽  
P. E. Prokhorova ◽  
O. A. Trofimova
Keyword(s):  
Scale Up ◽  
Laboratory Scale

scholarly journals Influence of Light Intensity and Temperature on Cultivation of Microalgae Desmodesmus Communis in Flasks and Laboratory-Scale Stirred Tank Photobioreactor

2015 ◽  
Vol 52 (2) ◽  
pp. 59-70 ◽  
Author(s):  
J. Vanags ◽  
L. Kunga ◽  
K. Dubencovs ◽  
V. Galvanauskas ◽  
O. Grīgs
Keyword(s):  
Light Intensity ◽  
Shake Flask ◽  
Scale Up ◽  
Biomass Concentration ◽  
Biomass Productivity ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Stirred Tank ◽  
Light Limitation ◽  
Maximum Biomass

Abstract Optimization of the microalgae cultivation process and of the bioprocess in general traditionally starts with cultivation experiments in flasks. Then the scale-up follows, when the process from flasks is transferred into a laboratory-scale bioreactor, in which further experiments are performed before developing the process in a pilot-scale reactor. This research was done in order to scale-up the process from a 0.4 1 shake flask to a 4.0 1 laboratory-scale stirred-tank photobioreactor for the cultivation of Desmodesmus (D.) communis microalgae. First, the effect of variation in temperature (21-29 ºC) and in light intensity (200-600 μmol m-2s-1) was studied in the shake-flask experiments. It was shown that the best results (the maximum biomass concentration of 2.72 g 1-1 with a specific growth rate of 0.65 g g-1d-1) can be achieved at the cultivation temperature and light intensity being 25 °C and 300 μmol m2s-1, respectively. At the same time, D. communis cultivation under the same conditions in stirred-tank photobioreactor resulted in average volumetric productivities of biomass due to the light limitation even when the light intensity was increased during the experiment (the maximum biomass productivity 0.25 g 1-1d-1; the maximum biomass concentration 1.78 g 1-1).

Granular Sludge Formation in the Anaerobic Expanded Micro-Carrier Bed Process

1989 ◽  
Vol 21 (4-5) ◽  
pp. 109-120 ◽  
Author(s):  
M. Yoda ◽  
M. Kitagawa ◽  
Y. Miyaji
Keyword(s):  
Scale Up ◽  
Granular Sludge ◽  
Laboratory Scale ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Expanded Bed ◽  
Sludge Formation ◽  
Support Materials ◽  
Anaerobic Sludge Blanket

The anaerobic expanded micro-carrier bed (MCB) process, which utilizes fine (50-100 microns) support materials as expanded bed media, was found to have the ability to cultivate granular sludge similar to that formed in the upflow anaerobic sludge blanket (UASB) process. Two laboratory-scale MCB reactors were studied with VFA and glucose wastewaters to clarify the role of the micro-carrier and the influence of substrates on granular sludge formation. Based on these results, a scale-up model with a reactor volume of 800 1 was successfully operated using molasses wastewater to demonstrate the feasibility of granular sludge formation in the MCB process.

A Tubeless V-Trough Solar Concentrator

1986 ◽  
Vol 10 (3) ◽  
pp. 135-140
Author(s):  
M. Issa Abdulhadi
Keyword(s):  
Experimental Investigation ◽  
Energy Balance ◽  
Analytical Approach ◽  
Mathematical Expression ◽  
Time Interval ◽  
Solar Concentrator ◽  
Late Afternoon ◽  
Heating And Cooling ◽  
Reliable Source ◽  
Good Agreement

An analytical, experimental investigation of the thermal performance of a tubeless V-trough concentrator has been carried out. Considering the energy balance on the receiver plate, a mathematical expression is developed from which the receiver plate mean temperature can be evaluated for each time interval. The good agreement between the experimental results and the analytical predictions indicate that the construction of a tubeless absorber panel might be valuable and the analytical approach might have the potential for further extensions. It has been found, according to the expermental investigation, that the fluid outlet temperatures vary between 69°C and 91 °C from 10:30 a.m. on up to the termination of operation in the late afternoon. This qualifies the V-trough to be a reliable source for providing temperatures in this range that can be utilized in heating and cooling applications.

Sign in / Sign up

Export Citation Format

Share Document