Study of the low-temperature two-stage fluidized bed incineration: Influence of the second-stage sand bed operating conditions on pollutant emission

2015 ◽  
Vol 75 ◽  
pp. 592-599 ◽  
Author(s):  
Tzu-Huan Peng ◽  
Chiou-Liang Lin ◽  
Ming-Yen Wey
Keyword(s):  
Low Temperature ◽  
Fluidized Bed ◽  
Operating Conditions ◽  
Pollutant Emission ◽  
Two Stage ◽  
Second Stage ◽  
Fluidized Bed Incineration

Supercritical Fluid Extraction of Polygonum cuspidatum and Subsequent Isolation by Simulated Moving Bed Chromatography

2013 ◽  
Vol 704 ◽  
pp. 18-30
Author(s):  
Ming Tsai Liang ◽  
Ru Chien Liang ◽  
Shu Qi Yu ◽  
Ri An Yan ◽  
Ku Yuan Liang
Keyword(s):  
Carbon Dioxide ◽  
Crude Extract ◽  
Operating Conditions ◽  
Effect Of Temperature ◽  
Simulated Moving Bed ◽  
Polygonum Cuspidatum ◽  
Two Stage ◽  
Moving Bed ◽  
Second Stage ◽  
Simulated Moving Bed Chromatography

In this work, supercritical carbon dioxide with ethanol as cosolvent was employed to extract bioactive compounds fromPolygonum Cuspidatum. Effect of temperature for 40 and 50 C on the extraction at 35 MPa was examined. It was found that extraction at 50 C resulted in high yield. A two-stage extraction at 50 C and 35 MPa was then designed to investigate effect of cosolvent on the recovery of resveratrol and emodin. The first stage extraction by solely using carbon dioxide can rarely extract resveratrol, but adding ethanol as cosolvent in the second stage significantly increases the extraction of resverarol and emodin. The crude extract obtained in the second stage was very stable against agglomeration and precipitation, because the first stage extraction helped to remove impurities from thePolygonum Cuspidatum. The stable crude extract was subsequently used as the feed for the SMB (simulated moving bed) separation. In this work, experimental validation was completed by solely using single SMB to isolate resveratrol, emodin, and physcion from the crude extract. As conducting the SMB experiments, the Triangle theory was used to help to determine the separable operating conditions. From the discussion of the experimental results, the criterion to obtain the pure resveratrol and physcion, and the concentrated emodin were depicted. Since both the extraction and the purification are conducted at low temperature, the bioactivity of the produced natural products will totally be preserved. The two-stage extraction and subsequent purification in this paper will provide greener and effective alternative for the development of botanical drugs.

scholarly journals The Impact of Hydraulic Retention Time on the Biomethane Production from Palm Oil Mill Effluent (POME) in Two-Stage Anaerobic Fluidized Bed Reactor

2020 ◽  
Vol 10 (1) ◽  
pp. 11-16
Author(s):  
Laily Isna Ramadhani ◽  
Sri Ismiyati Damayanti ◽  
Hanifrahmawan Sudibyo ◽  
Muhammad Mufti Azis ◽  
Wiratni Budhijanto
Keyword(s):  
Fluidized Bed ◽  
Palm Oil ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Ph Control ◽  
Palm Oil Mill Effluent ◽  
Two Stage ◽  
Second Stage ◽  
Biomethane Production ◽  
Palm Oil Mill

Indonesia is currently the most significant crude palm oil (CPO) producer in the world. In the production ofCPO, 0.7m3 of Palm Oil Mill Effluent (POME) is emitted as the wastewater for every ton of fresh fruit bunches processed in the palm oil mill.With the increasing amount of CPO production, an effective POME treatment system is urgently required to prevent severe environmental damage. The high organic content in the POME is a potential substrate forbio-methane production. The biomethane production is carried out by two groups of microbes, i.e., acidogenic and methanogenic microbes. Each group of bacteria performs optimally at different optimum conditions. To optimize the biomethane production, POME was treated sequentially by separating the acidogenic and methanogenic microbes into two stages of anaerobic fluidized bed reactors (AFBR). The steps were optimized differently according to the favorable conditions of each group of bacteria. Although perfect separation cannot be achieved, this study showed that pH control could split the domination of the bacteria, i.e., the first stage (maintained at pH 4-5) was dominated by the acidogenic microbes and the second stage (kept neutral) was governed by methanogens. In addition to the pH control, natural zeolitewas added as microbial immobilization media in the AFBR to improve the performance of the microorganisms, especially in preventing microbial wash out at short hydraulic retention time (HRT). This study was focused on the understanding of the effect of HRT on the performance of steady-state continuous AFBR. The first stage as the acidogenic reactorwas rununder acidic conditions (pH 4-5) at five different HRTs. In comparison, the second stage as the methanogenic reactorwasrun under the neutral condition at four different HRTs. In this work,short HRT (5 days) resulted in better performance in both acidogenic AFBR and methanogenic AFBR. The immobilization media was hence essential to reduce the risk of washout at such a short HRT. The two-stage system also resulted in quite a high percentage of soluble chemical oxygen demand (sCOD) removal, which was as much as 96.06%sCOD.

Study on Black Liquor Low-temperature Gasification in Fluidized Bed by Eulerian Multiphase Computationally Fluid Dynamics Modeling

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Weiling Li ◽  
Wenqi Zhong ◽  
Baosheng Jin ◽  
Rui Xiao ◽  
Yingjuan Shao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Fluidized Bed ◽  
Reaction Rate ◽  
Solid Phase ◽  
Heterogeneous Reaction ◽  
Black Liquor ◽  
Molar Fraction ◽  
Reaction Rates ◽  
Operating Conditions ◽  
Heterogeneous Reactions

Abstract A three-dimensional Eulerian multiphase based computational model was developed to simulate the black liquor gasification processes in a fluidized bed gasifier (FBG) at low temperature. The standard k-e model and kinetic theory of granular model were used to simulate the gas phase and solid phase, respectively. Black liquor pyrolysis, homogeneous reactions and heterogeneous reactions were taken into account in chemical model. The reaction rates of homogeneous and heterogeneous reaction were determined by Arrhenius–Eddy dissipation reaction rate and kinetic reaction rate. Simulations were carried out at four different operating conditions, i.e. reactor temperature was kept at 550 degree centigrade or 600 degree centigrade, and nitrogen or air was used as fluidizing medium. The calculated results were in well agreement with the experiment used as calibration. Base on the simulation, gas-sold flow patterns and gas species molar fraction distributions were obtained, the relationship of gas composition profiles with the temperature and the fluidizing media were discussed.

scholarly journals Development of two-stage multi-anvil apparatus for low-temperature measurements

2019 ◽  
Vol 11 ◽  
pp. 110006
Author(s):  
K. Ishigaki ◽  
J. Gouchi ◽  
S. Nagasaki ◽  
J. G. Cheng ◽  
Y. Uwatoko
Keyword(s):  
High Pressure ◽  
Low Temperature ◽  
Room Temperature ◽  
Edge Length ◽  
Hydraulic Press ◽  
Temperature Measurements ◽  
Two Stage ◽  
Sample Container ◽  
Total Size ◽  
Second Stage

The two-stage 6-8 multi-anvil (MA8) apparatus is an important large-volume, high-pressure technique that has been widely used in the high pressure mineralogy and material synthesis, mainly at room temperature or above. Recently, we have successfully developed a two-stage MA8 apparatus for low-temperature physical property measurements. The first-stage anvils at top and bottom sides are fabricated as a single piece in order to reduce the total size of the cylindrical module, which is put in a top-loading high pressure cryostat and compressed by a 1000 ton hydraulic press. A castable, split octahedral gasket with integrated fin was specifically designed in order to introduce the electrical leads from the inside sample container filled with a liquid pressure transmitting medium. By using tungsten carbide (WC) second-stage cubes with a truncated edge length of 3 mm and an octahedral gasket with an edge length of 6 mm, we have successfully generated pressure over 20 GPa at room temperature. Since the high pressure limit can be pushed to nearly 100 GPa by using the sintered diamond second-stage cubes, our MA8 apparatus has a great potential to expand the current pressure capacity for precise low-temperature measurements with a large sample volume. Edited by: A. Goñi, A. Cantarero, J. S. Reparaz

DIFFUSION ACTIVITY OF CARBON DURING POLYMORPHIC TRANSFORMATION OF STEEL AND TWO-STAGE LOW-TEMPERATURE CEMENTATION

2020 ◽  
pp. 3-10
Author(s):  
B. V. Fokin ◽  
A. A. Zhukov ◽  
A. P. Navoev ◽  
Yu. A. Kustov ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Polymorphic Transformation ◽  
Interatomic Interaction ◽  
Carbon Diffusion ◽  
Two Stage ◽  
Two Phase ◽  
Second Stage ◽  
Required Quality

It was studied diffusive mobility of carbon’s atoms in the process of decarbonation steel У8 and cementation steel Ст3 in the temperature’s interval of polymorphic transformation. It was set that low temperature cementation (LTC) is possible only after a preliminary austenitization steel. In the state of polymorphic transformation due to the weakening of interatomic interaction, the formation of a two-phase structure of complexes, there is a decrease in the activation energy of carbon diffusion and a corresponding increase in the diffusion coefficient, which indicates the possibility of conducting LTC. The diffusion ability of carbon in LTC in a two-phase state was estimated using the value of the effective activation energy of diffusion taking into account the relative content of austenite and ferrite according to the «lever» rule. As a result of the studies performed, the following two-stage LTC method is proposed: the first stage – austenization (carburization) of the surface layer at a temperature of 920 °С for 20 minutes; the second stage – cementation in the temperature range 700…740 °С for 2 hours. Subsequent hardening and low-temperature tempering provide the required quality of the cemented layer by analogy with the traditional cementation process.

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