scholarly journals Integrated Ozonation-Enzymatic Hydrolysis Pretreatment of Sugarcane Bagasse: Enhancement of Sugars Released to Expended Ozone Ratio

Processes ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 1274 ◽  
Author(s):  
Daryl Rafael Osuna-Laveaga ◽  
Octavio García-Depraect ◽  
Ramiro Vallejo-Rodríguez ◽  
Alberto López-López ◽  
Elizabeth León-Becerril
Keyword(s):  
Enzymatic Hydrolysis ◽  
Sugarcane Bagasse ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Particle Sizes ◽  
Combined Effects ◽  
Sugar Release ◽  
The Relationship ◽  
Ozonation Process

The combined effects of three key ozonation process parameters on the integrated ozonation-enzymatic hydrolysis pretreatment of sugarcane bagasse (SCB) were investigated, with emphasis on the relationship between sugar release and ozone consumption. A lab-scale fixed bed reactor was employed for ozonation at varying ozone doses (50, 75 and 100 mg O3/g SCB), particle sizes (420, 710 and 1000 µm) and moisture contents (30, 45 and 60% w/w) in multifactorial experiments, keeping a residence time of 30 min. The ozonated SCB showed a reduction in the content of acid-insoluble lignin from 26.6 down to 19.1% w/w, while those of cellulose and hemicellulose were retained above 45.5 and 13.6% w/w, with recoveries of 100–89.9 and 83.5–72.7%, respectively. Ozone-assisted enzymatic hydrolysis allowed attaining glucose and xylose yields as high as 45.0 and 37.8%, respectively. The sugars released/ozone expended ratio ranged between 2.3 and 5.7 g sugars/g O3, being the higher value achieved with an applied ozone input of 50 mg O3/g SCB and SCB with 420 µm particle size and 60% moisture. Such operating conditions led to efficient ozone utilization (<2% unreacted ozone) with a yield of 0.29 g sugars/g SCB. Overall, the amount of sugars released relative to the ozone consumed was improved, entailing an estimated cost of ozonation of USD 34.7/ton of SCB, which could enhance the profitability of the process.

Role of filter media in an anaerobic fixed-bed reactor

1995 ◽  
Vol 31 (9) ◽  
pp. 137-144 ◽  
Author(s):  
T. Miyahara ◽  
M. Takano ◽  
T. Noike
Keyword(s):  
Anaerobic Bacteria ◽  
Fixed Bed ◽  
Methanogenic Bacteria ◽  
The Other ◽  
Fixed Bed Reactor ◽  
Filter Media ◽  
Fixed Bed Reactors ◽  
Attached Bacteria ◽  
The Relationship

The relationship between the filter media and the behaviour of anaerobic bacteria was studied using anaerobic fixed-bed reactors. At an HRT of 48 hours, the number of suspended acidogenic bacteria was higher than those attached to the filter media. On the other hand, the number of attached methanogenic bacteria was more than ten times as higher than that of suspended ones. The numbers of suspended and deposited acidogenic and methanogenic bacteria in the reactor operated at an HRT of 3 hours were almost the same as those in the reactor operated at an HRT of 48 hours. Accumulation of attached bacteria was promoted by decreasing the HRT of the reactor. The number of acidogenic bacteria in the reactor packed sparsely with the filter media was higher than that in the closely packed reactor. The number of methanogenic bacteria in the sparsely packed reactor was lower than that in the closely packed reactor.

Modeling of a Fixed-Bed Reactor for the Production of Phthalic Anhydride

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Amir Rahimi ◽  
Sogand Hamidi
Keyword(s):  
Phthalic Anhydride ◽  
Fixed Bed ◽  
Tubular Reactor ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Conversion Degree ◽  
Reactor Length ◽  
Reactor Temperature ◽  
Reported Data ◽  
Reactor Pressure

In this study, the performance of a fixed–bed tubular reactor for the production of phthalic anhydride is mathematically analyzed. The conversion degree and reactor temperature values are compared with the measured one in a tubular reactor applied in Farabi petrochemical unit in Iran as well as reported data in the literature for a pilot plate. The comparisons are satisfactory. The effects of some operating parameters including reactor length, feed temperature, reactor pressure, and existence of an inert in the catalytic bed are investigated. The optimum value of each parameter is determined on the basis of the corresponding operating conditions.

Production of quicklime from Ashaka limestone through calcination process

2021 ◽  
Vol 1 (2) ◽  
pp. 041-048
Author(s):  
Benson Chinweuba Udeh
Keyword(s):  
Particle Size ◽  
Critical Value ◽  
Operating Conditions ◽  
Quadratic Model ◽  
Particle Sizes ◽  
Calcination Process ◽  
Process Effects ◽  
Effects Of Temperature ◽  
The Difference ◽  
The Relationship

This study is on the production of quicklime from Ashaka limestone through calcination process. Effects of temperature, particle size and time on quicklime yield were determined. The experiment was carried out at temperatures of 800, 900, 1000, 1100 and 1200 0C, particle sizes of 80mm, 90mm, 100mm, 300mm and 425mm and times of 0.5hr, 1hr, 2hrs, 3hrs and 4hrs. Analyses of the results showed that quicklime was successfully produced from Ashaka limestone through the calcination process. Quadratic model adequately described the relationship between quicklime yield and calcination factors of temperature, particle size and time. Recorded model F-value of 134.35 implies that the model is significant. The predicted R² of 0.9597 is in reasonable agreement with the adjusted R² of 0.9844; the difference is less than the critical value of 0.2. Optimum yield of 73.48% was obtained at optima operating conditions; temperature of 1000 0C, particle size of 90 µm and time of 3 hrs.

Development of an integrated thermal and enzymatic hydrolysis for lignocellulosic biomass in fixed-bed reactors

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Christian Kirsch ◽  
Carsten Zetzl ◽  
Irina Smirnova
Keyword(s):  
Enzyme Activity ◽  
Enzymatic Hydrolysis ◽  
Lignocellulosic Biomass ◽  
Elevated Temperatures ◽  
Enzyme Stability ◽  
Fixed Bed ◽  
Residual Activity ◽  
Fixed Bed Reactor ◽  
Shear Forces ◽  
Glucose Yield

Abstract The limitations of the current biorefinery process utilizing stirred-tank reactors for the enzymatic step include poor mixing in the case of high biomass loadings, additional steps for the product separation, and a long reaction time. In this study the hydrothermal pretreatment and the enzymatic hydrolysis of the lignocellulosic biomass were combined in one fixed-bed reactor. The influence of the shear forces during recirculation and enzyme stability at elevated temperatures were investigated. It has been shown that the shear forces resulting from pumping have a negligible effect on enzyme activity. However, large pressure drops reduce the enzyme activity significantly. Furthermore, the enzyme stability was significantly increased at elevated temperatures (60°C) by applying static pressures up to 200 bar (56% residual activity at 60°C after 24 h). This is beneficial for the process as a higher temperature accelerates the reaction. Further improvement of the overall process efficiency was achieved by increasing the solid-to-water ratio and circulation of the enzyme solution. At a biomass content of 7%, a glucose concentration of 61 g l-1 and a yield of 85% was achieved. The integrated process was first done on a laboratory scale (50 ml). At 100 bar, 60°C and 10% biomass loading an increased initial reaction rate was observed. However, this effect was followed by the stagnation of the glucose yield as one of the enzymes, Novozyme 188, showed no remarkable stabilization with pressure. Nevertheless, an overall glucose yield of 40% was achieved after 5.5 h, compared to 14 h under normal pressure and 50°C.

Solar-driven steam-based gasification of sugarcane bagasse in a combined drop-tube and fixed-bed reactor – Thermodynamic, kinetic, and experimental analyses

2013 ◽  
Vol 52 ◽  
pp. 173-183 ◽  
Author(s):  
Michael Kruesi ◽  
Zoran R. Jovanovic ◽  
Elena C. dos Santos ◽  
Hyung Chul Yoon ◽  
Aldo Steinfeld
Keyword(s):  
Sugarcane Bagasse ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Drop Tube ◽  
Experimental Analyses

Theoretical Investigations of Methane Conversion to Heavier Hydrocarbons in a Plasma Reactor

2012 ◽  
Vol 548 ◽  
pp. 153-159
Author(s):  
Mohammad Kazemeini ◽  
Masoud Habibi Zare ◽  
Nora Safabakhsh ◽  
Shadi Roshdi Ferdosi ◽  
Moslem Fattahi
Keyword(s):  
Methane Conversion ◽  
Plasma Reactor ◽  
Fixed Bed ◽  
Oxidative Coupling Of Methane ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Plasma Process ◽  
Process Yield ◽  
Theoretical Investigations ◽  
Product And Process

In this study, mathematical modelling of oxidative coupling of methane (OCM) to C2hydrocarbons (C2H6and C2H4) over La2O3/CaO catalyst in a fixed-bed reactor operated under isothermal and non-isothermal conditions was investigated using the MATLAB program. In this process, methane and acetylene were the inputted feed and ethane, ethylene, propylene, propane, i-butane and n-butane were the output products. The amount of methane conversion obtained was 12.7% for the former feed however; if pure methane was inputted this conversion rose to 13.8%. Furthermore, the plasma process would enhance the conversion, selectivity towards desired product and process yield. A comparison between the thermal and the plasma process showed that the methane conversion and production yield in the plasma were higher than in the thermal process under the same operating conditions. Finally, the results of the catalytic OCM and methane conversion processes in the plasma phase were compared with one another.

The Fixed Bed Reaction of Residual Natural Rubber for Oil Production by Pyrolysis Process

2014 ◽  
Vol 931-932 ◽  
pp. 225-230
Author(s):  
Khanita Kamwilaisak ◽  
Mallika Thabuot
Keyword(s):  
Particle Size ◽  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Maximum Amount ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Pyrolysis Process ◽  
Pyrolysis Reaction ◽  
Benzenedicarboxylic Acid ◽  
Chemical Feedstock

The aim of this study is to use pyrolysis reaction to produce oil product as a fuel or chemical feedstock. The fixed bed reactor was used as a pyrolysis system. The pyrolysis reaction of residual para rubber was operated in the absence of catalyse. The operating conditions such as particle size (0.5 and 1.0 cm3) and pyrolysis temperature (500, 550 and 600 OC) were studied under N2 conditions and retention time 90 min. The result shows the para rubber size 1.0 cm3 can be produced liquid phase more than of para rubber size of 0.5 cm3. The optimised condition with the highest oil yield was at 550OC with rubber size of 1.0 cm3. The percentage of the product was 60% of liquid, 35% of gas and 5% of solid (char). Furthermore, the FTIR result can be presented the supported evidence that the transformation of aliphatic contents to be aromatic contents was increased with increased temperature. Also, GCMS analysis was used for the identification and quantification of the product. It was found 5 major products that can be used as a chemical feedstock. The maximum amount of component was 2-Benzenedicarboxylic acid, diisooctyl ester (Isooctyl phthalate) with 22.08%. This is a plasticizer with higher cost than fuel.

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