Hydrogen Chloride Release From Combustion of Corn Straw in a Fixed Bed

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
Xiaohan Ren ◽  
Xiaoxiao Meng ◽  
Aidin Panahi ◽  
Emad Rokni ◽  
Rui Sun ◽  
...  
Keyword(s):  
Hydrogen Chloride ◽  
Flow Rate ◽  
Air Flow ◽  
Fixed Bed ◽  
Air Flow Rate ◽  
Corn Straw ◽  
Release Rates ◽  
Torrefied Biomass ◽  
Hcl Gas ◽  
Biomass Ashes

Chlorine plays an important role in the slagging and corrosion of boilers that burn high-chlorine content biomass. This research investigated the emissions of hydrogen chloride (HCl) gas from combustion of biomass in a fixed bed, as functions of the mass air flow rate through the bed and of the moisture content of the fuel. The biomass burned was corn straw, either raw or torrefied. Results showed that increasing the air flow rate through the bed increased the release of HCl gas, as a result of enhanced combustion intensity and associated enhanced heat release rates. When the airflow through the bed was increased by a factor of six, the amount of fuel-bound chlorine converted to HCl nearly tripled. Upon completion of combustion, most of the chlorine remained in the biomass ashes, with the exception of the highest air flow case where the fraction of chlorine released in HCl equaled that captured in the ashes. HCl emissions from torrefied biomass were found to be lower than those from raw biomass. Finally, drying the biomass proved to be beneficial in drastically curtailing the generation of HCl gas.

Parametric studies on corn combustion characteristics in a fixed bed: Primary air flow rate and different corn lengths

2017 ◽  
Vol 126 ◽  
pp. 702-716 ◽  
Author(s):  
Xiaoxiao Meng ◽  
Rui Sun ◽  
Tamer M. Ismail ◽  
Wei Zhou ◽  
Xiaohan Ren ◽  
...  
Keyword(s):  
Flow Rate ◽  
Air Flow ◽  
Fixed Bed ◽  
Combustion Characteristics ◽  
Air Flow Rate ◽  
Parametric Studies

scholarly journals Experimental analysis of the influence of air-flow rate on wheat straw combustion in a fixed bed

2017 ◽  
Vol 21 (3) ◽  
pp. 1443-1452 ◽  
Author(s):  
Zoran Cepic ◽  
Branka Nakomcic-Smaragdakis
Keyword(s):  
Wheat Straw ◽  
Burning Rate ◽  
Flow Rate ◽  
Crop Residues ◽  
Air Flow ◽  
Combustion Process ◽  
Fixed Bed ◽  
Air Flow Rate ◽  
Experimental Rig ◽  
Straw Combustion

Biomass in the form of crop residues represents a significant energy source in regions whose development is based on agricultural production. Among many possibilities of utilizing biomass for energy generation, combustion is the most common. With the aim of improving and optimizing the combustion process of crop residues, an experimental rig for straw combustion in a fixed bed was constructed. This paper gives a brief review of working characteristics of the experimental rig, as well as the results for three different measuring regimes, with the purpose to investigate the effect of air-flow rate on the wheat straw combustion in a fixed bed. For all three regimes analysed in this paper bulk density of the bed was the same, 60 kg/m3, combustion air was without preheating and air-flow rates were: 1152, 1872, and 2124 kg/m2h. The effect of air-flow rate on the ignition rate, burning rate, temperature profile of the bed and flue gas composition were analysed. It was concluded that in the regime with the lowest air-flow rate progress of combustion had two clearly conspicuous stages: the ignition propagation stage and the char and unburned material oxidation stage. At the highest air-flow rate the entire combustion occurred mostly in a single stage, due to increased air supply oxidized the char, remaining above the ignition front, simultaneously with the reactions of volatiles. Despite that, the optimal combustion process, the highest value of ignition rate, burning rate, and bed temperature was achieved with air-flow rate of 1872 kg/m2h.

scholarly journals Lipase production by solid-state fermentation in fixed-bed bioreactors

2005 ◽  
Vol 48 (spe) ◽  
pp. 79-84 ◽  
Author(s):  
Elisa d'Avila Costa Cavalcanti ◽  
Melissa Limoeiro Estrada Gutarra ◽  
Denise Maria Guimarães Freire ◽  
Leda dos Reis Castilho ◽  
Geraldo Lippel Sant'Anna Júnior
Keyword(s):  
Solid State ◽  
Flow Rate ◽  
Solid State Fermentation ◽  
Air Flow ◽  
Fixed Bed ◽  
Packed Bed ◽  
Lipase Production ◽  
Statistical Experimental Design ◽  
Air Flow Rate ◽  
Penicillium Simplicissimum

In the present work, packed bed bioreactors were employed with the aim of increasing productivity and scaling up of lipase production using Penicillium simplicissimum in solid-state fermentation. The influence of temperature and air flow rate on enzyme production was evaluated employing statistical experimental design, and an empirical model was adjusted to the experimental data. It was shown that higher lipase activities could be achieved at lower temperatures and higher air flow rates. The maximum lipase activity (26.4 U/g) was obtained at the temperature of 27°C and air flow rate of 0.8 L/min.

KARAKTERISTIK HILANG TEKAN ALIRAN UDARA MELALUI TUMPUKAN SERBUK GERGAJI DI FIXED BED REACTOR

EKUILIBIUM ◽  
2015 ◽  
Vol 13 (1) ◽  
Author(s):  
Sunu Herwi Pranolo
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Air Flow ◽  
Fixed Bed ◽  
Average Diameter ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Air Flow Rate ◽  
Independent Variables ◽  
Bed Porosity

<p>Abstract : Solid Bed in fixed bed gasifier tends to cause the pressure drop that resulting energy<br />loss. Thus, the main cause needs analysis in order to obtain the operating conditions that<br />minimize energy loss. Pressure drop at the fixed bed gasifier is influenced by the particle<br />diameter, bed porosity and shape factor of the solid particle. This research purposed to analyze<br />influence of air flow rate and depth of sawdust bed in the fixed bed gasifier. The experiments<br />were performed by air flux from the blower. This research analyzed two conditions of the<br />gasifier, empty and filled with the bed of sawdust. Average diameter (D<br />p<br />) of 0,02 cm was<br />selected as constant variable and the independent variables were depth of bed (L) and air<br />superficial velocity (G). The experiments air superficial velocities were in the range of 1,3154 –<br />1,3891 g/cm<br />s and depth of bed at 15 cm, 30 cm, 45 cm. Experimental results showed that the<br />trend of the pressure drop is proportional to the air flow rate and to the depth of sawdust bed.<br />2<br />Keywords: pressure drop, sawdust, gasification</p>

scholarly journals Model of thermal buoyancy in cavity-ventilated roof constructions

2021 ◽  
pp. 174425912098418
Author(s):  
Toivo Säwén ◽  
Martina Stockhaus ◽  
Carl-Eric Hagentoft ◽  
Nora Schjøth Bunkholt ◽  
Paula Wahlgren
Keyword(s):  
Analytical Model ◽  
Flow Rate ◽  
Numerical Study ◽  
Air Flow ◽  
Wind Pressure ◽  
Air Flow Rate ◽  
Test Set ◽  
Air Cavity ◽  
Thermal Buoyancy ◽  
The Impact

Timber roof constructions are commonly ventilated through an air cavity beneath the roof sheathing in order to remove heat and moisture from the construction. The driving forces for this ventilation are wind pressure and thermal buoyancy. The wind driven ventilation has been studied extensively, while models for predicting buoyant flow are less developed. In the present study, a novel analytical model is presented to predict the air flow caused by thermal buoyancy in a ventilated roof construction. The model provides means to calculate the cavity Rayleigh number for the roof construction, which is then correlated with the air flow rate. The model predictions are compared to the results of an experimental and a numerical study examining the effect of different cavity designs and inclinations on the air flow rate in a ventilated roof subjected to varying heat loads. Over 80 different test set-ups, the analytical model was found to replicate both experimental and numerical results within an acceptable margin. The effect of an increased total roof height, air cavity height and solar heat load for a given construction is an increased air flow rate through the air cavity. On average, the analytical model predicts a 3% higher air flow rate than found in the numerical study, and a 20% lower air flow rate than found in the experimental study, for comparable test set-ups. The model provided can be used to predict the air flow rate in cavities of varying design, and to quantify the impact of suggested roof design changes. The result can be used as a basis for estimating the moisture safety of a roof construction.

scholarly journals Modeling and optimization of radish root extract drying as peroxidase source using spouted bed dryer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahrbanoo Hamedi ◽  
M. Mehdi Afsahi ◽  
Ali Riahi-Madvar ◽  
Ali Mohebbi
Keyword(s):  
Kinetic Parameters ◽  
Flow Rate ◽  
Air Flow ◽  
Cost Effective ◽  
Industrial Applications ◽  
Interactive Effects ◽  
Root Extract ◽  
Air Flow Rate ◽  
Spouted Bed ◽  
Radish Root

AbstractThe main advantages of the dried enzymes are the lower cost of storage and longer time of preservation for industrial applications. In this study, the spouted bed dryer was utilized for drying the garden radish (Raphanus sativus L.) root extract as a cost-effective source of the peroxidase enzyme. The response surface methodology (RSM) was used to evaluate the individual and interactive effects of main parameters (the inlet air temperature (T) and the ratio of air flow rate to the minimum spouting air flow rate (Q)) on the residual enzyme activity (REA). The maximum REA of 38.7% was obtained at T = 50 °C and Q = 1.4. To investigate the drying effect on the catalytic activity, the optimum reaction conditions (pH and temperature), as well as kinetic parameters, were investigated for the fresh and dried enzyme extracts (FEE and DEE). The obtained results showed that the optimum pH of DEE was decreased by 12.3% compared to FEE, while the optimum temperature of DEE compared to FEE increased by a factor of 85.7%. Moreover, kinetic parameters, thermal-stability, and shelf life of the enzyme were considerably improved after drying by the spouted bed. Overall, the results confirmed that a spouted bed reactor can be used as a promising method for drying heat-sensitive materials such as peroxidase enzyme.

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