scholarly journals The main natural lows of high-rate coal pyrolysis

2003 ◽  
Vol 7 (2) ◽  
pp. 77-87 ◽  
Author(s):  
Nikola Chemyavsky
Keyword(s):  
Fluidized Bed ◽  
Total Yield ◽  
Pilot Scale ◽  
Thermal Conversion ◽  
High Rate ◽  
Coal Pyrolysis ◽  
Heating Rates ◽  
Method Of Calculation ◽  
Entrained Flow ◽  
Energy Technologies

The importance of coal pyrolysis studies for the development of energy technologies is evident, since pvrolysis is the first stage of any process of coal thermal conversion. In combustion, pyrolysis determines conditions of coal ignition and the rate of char after-burning, in gasification, pyrolysis determines total yield of gasification products. It must be noted that in modern energy technologies pyrolysis occurs at high late of coal particle heating (=10 K/s for different fluidized bed, or FB-technologies) or super-high-rate (>10**5 K/s for entrained-flow gasification), and in some of them at high pressure. In CETI during last 12 years the detailed study of pyrolysis in FB laboratory-scale PYROLYSIS-D plant and entramed-flow pilot-scale GSP-01 plant, was carried out. In this paper main results of mentioned investigations are given. Kinetic constants for bituminous coals and anthracite high heating rates in entrained flow for high temperatures (>1500 ?C and >1900 ?C), and in fluidized bed conditions in temperature range 972-1273 K. In order to describe data obtained in fluidized bed conditions, G--model based method of calculation of devolatization dynamics was suited to FB heating conditions. Calculated and experimental kinetic data are in good agreement. The result proves that at FB-pvrolysis conditions intrinsic mass-transfer limitations are negligible and devolatilization is really kinetic-controlled.

Fluidized-bed biofilms for chlorophenol mineralization

1995 ◽  
Vol 31 (1) ◽  
pp. 227-235 ◽  
Author(s):  
Jaakko A. Puhakka ◽  
Esa S. Melin ◽  
Kimmo T. Järvinen ◽  
Päivi M. Koro ◽  
Jukka A. Rintala ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Groundwater Remediation ◽  
Research Effort ◽  
Treatment Strategies ◽  
Sole Source ◽  
Pilot Scale ◽  
High Rate ◽  
Contaminated Groundwater ◽  
Groundwater Temperature ◽  
Loading Rates

This paper summarizes a five-year research effort on the development of a high-rate fluidized-bed biofilm system for remediation of chlorophenol contaminated groundwater. Laboratory-scale experiments with model compounds and actual contaminated groundwater included studies on aerobic and anoxic treatment, strategies for selective enrichment of chlorophenol degrading microorganisms, kinetics and stoichiometries of chlorophenol conversions, toxicity removal, growth and culture characterization, recovery from process upsets, and operation at suboptimal temperatures. The aerobic process using chlorophenols as the sole source of carbon and energy showed the greatest versatility and efficiency. The contaminated groundwater consisted of 2,3,4,6-tetrachlorophenol, 2,4,6-trichlorophenol and pentachlorophenol with total chlorophenol concentrations ranging from 45 to 55 mg/l. At room temperature, groundwater remediation resulted in over 99.9% mineralization at chlorophenol loading rates of 1000 mg/l/d and hydraulic retention times of less than 1h. At the groundwater temperature (7°C), similar removal efficiencies were obtained at chlorophenol loading rates of up to 740 mg/l/d. The laboratory results were successfully repeated in an on-site, pilot-scale demonstration.

Pemodelan Reaktor Hibrid Anaerob Pengolah Molasse Pada Pembebanan Organik Tinggi

2020 ◽  
Author(s):  
Gede H Cahyana
Keyword(s):  
Fluidized Bed ◽  
Fixed Bed ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Expanded Bed ◽  
Anaerobic Sludge Blanket

Telah dikembangkan reaktor anaerob kecepatan tinggi (high rate) yang merupakan modifikasi reaktor konvensional. Di antaranya berupa (bio)reaktor pertumbuhan tersuspensi (contoh: UASB, Upflow Anaerobic Sludge Blanket) dan reaktor pertumbuhan lekat (Fixed Bed atau Biofilter, Fluidized Bed, Expanded Bed, Rotating Biodisc dan Baffled Reactor). Kedua tipe reaktor di atas memiliki sejumlah kelebihan dan kekurangan. Untuk mengoptimalkan nilai positifnya (terutama untuk keperluan desain) maka reaktor tersebut, pada penelitian ini, disusun menjadi satu urutan yang disebut Reaktor Hibrid Anaerob (Rehan) yakni UASB di bawah dan AF di atasnya. Lebih lanjut, penelitian ini diharapkan dapat memberikan informasi tentang kinerja Rehan dalam mengolah air limbah (substrat) yang konsentrasi zat organiknya (COD) sangat tinggi dan suatu model matematika yang dapat mewakili reaktor tersebut.

Viability of nematode eggs in high rate algal ponds: the effect of physico-chemical conditions

2000 ◽  
Vol 42 (10-11) ◽  
pp. 371-374 ◽  
Author(s):  
S. Araki ◽  
J. M. González ◽  
E. de Luis ◽  
E. Bécares
Keyword(s):  
Hydraulic Retention Time ◽  
Pilot Scale ◽  
High Rate ◽  
Sterile Water ◽  
Egg Viability ◽  
High Rate Algal Ponds ◽  
Helminth Eggs ◽  
Physico Chemical ◽  
Nematode Eggs ◽  
Chemical Conditions

The viability of Parascaris equorum eggs was studied in two experimental pilot-scale high-rate algal ponds (HRAPs) working in parallel with 4 and 10 days hydraulic retention time respectively. Semi-permeable bags of cellulose (15000 daltons pore size) were used to study the effect of physico-chemical conditions on the survival of these helminth eggs. Three thousand eggs were used in each bag. Replicates of these bags were submerged for 4 and 10 days in the HRAPs and egg viability was compared with that in control bags submerged in sterile water. After 4 days exposure, 60% reduction in viability was achieved, reaching 90% after 10 days, much higher than the 16% and 25% found in the control bags for 4 and 10 days respectively. Ionic conditions of the HRAP may have been responsible for up to 50–60% of the egg mortality, suggesting that mortality due to the ionic environment could be more important than physical retention and other potential removal factors.

On-site and in situ bioremediation of wood-preservative contaminated groundwater

2000 ◽  
Vol 42 (5-6) ◽  
pp. 371-376 ◽  
Author(s):  
J.A. Puhakka ◽  
K.T. Järvinen ◽  
J.H. Langwaldt ◽  
E.S. Melin ◽  
M.K. Männistö ◽  
...  
Keyword(s):  
Iron Oxidation ◽  
Wood Preservative ◽  
Pilot Scale ◽  
High Rate ◽  
Contaminated Groundwater ◽  
Groundwater Temperature ◽  
In Situ Bioremediation ◽  
Contaminated Aquifer ◽  
Fluidized Bed Process

This paper reviews ten years of research on on-site and in situ bioremediation of chlorophenol contaminated groundwater. Laboratory experiments on the development of a high-rate, fluidized-bed process resulted in a full-scale, pump-and-treat application which has operated for several years. The system operates at ambient groundwater temperature of 7 to 9°C at 2.7 d hydraulic retention time and chlorophenol removal efficiencies of 98.5 to 99.9%. The microbial ecology studies of the contaminated aquifer revealed a diverse chlorophenol-degrading community. In situ biodegradation of chlorophenols is controlled by oxygen availability, only. Laboratory and pilot-scale experiments showed the potential for in situ aquifer bioremediation with iron oxidation and precipitation as a potential problem.

Fluidized bed gasification of eucalyptus chips: Axial profiles of syngas composition in a pilot scale reactor

Energy ◽  
2021 ◽  
Vol 219 ◽  
pp. 119604
Author(s):  
Francesco Parrillo ◽  
Filomena Ardolino ◽  
Gabriele Calì ◽  
Davide Marotto ◽  
Alberto Pettinau ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Pilot Scale ◽  
Pilot Scale Reactor ◽  
Scale Reactor

Performance of an entrained-flow gasification technology of pulverized coal in pilot-scale plant

2007 ◽  
Vol 88 (5) ◽  
pp. 451-459 ◽  
Author(s):  
Xiaolei Guo ◽  
Zhenghua Dai ◽  
Xin Gong ◽  
Xueli Chen ◽  
Haifeng Liu ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Pulverized Coal ◽  
Entrained Flow ◽  
Entrained Flow Gasification ◽  
Gasification Technology

scholarly journals Kinetic Parameters of Nut Shells Pyrolysis

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 682
Author(s):  
Tomasz Noszczyk ◽  
Arkadiusz Dyjakon ◽  
Jacek A. Koziel
Keyword(s):  
Kinetic Parameters ◽  
Waste Treatment ◽  
Model Fitting ◽  
Thermal Conversion ◽  
Point Of View ◽  
The European Union ◽  
Heating Rates ◽  
Isothermal Model ◽  
Biomass Residues ◽  
Conversion Point

The European Union created a European Green Deal Program (EGDP). This program aims at a sustainable economy through the transformation of the challenges related to climate and the environment. The main goal of EGDP is climate neutrality by 2050. The increase of alternative biomass residues utilization from various food processing industries and cooperation in the energy and waste management sector is required to meet these expectations. Nut shells are one of the lesser-known, yet promising, materials that can be used as an alternative fuel or a pre-treated product to further applications. However, from a thermal conversion point of view, it is important to know the energy properties and kinetic parameters of the considered biowaste. In this study, the energy and kinetic parameters of walnut, hazelnut, peanut, and pistachio shells were investigated. The results showed that raw nut shells are characterized by useful properties such as higher heating value (HHV) at 17.8–19.7 MJ∙kg−1 and moisture content of 4.32–9.56%. After the thermal treatment of nut shells (torrefaction, pyrolysis), the HHV significantly increased up to ca. 30 MJ∙kg−1. The thermogravimetric analysis (TGA) applying three different heating rates (β; 5, 10, and 20 °C∙min−1) was performed. The kinetic parameters were determined using the isothermal model-fitting method developed by Coats–Redfern. The activation energy (Ea) estimated for β = 5 °C∙min−1, was, e.g., 60.3 kJ∙mol−1∙K−1 for walnut, 59.3 kJ∙mol−1∙K−1 for hazelnut, 53.4 kJ∙mol−1∙K−1 for peanut, and 103.8 kJ∙mol−1∙K−1 for pistachio, respectively. Moreover, the increase in the Ea of nut shells was observed with increasing the β. In addition, significant differences in the kinetic parameters of the biomass residues from the same waste group were observed. Thus, characterization of specific nut shell residues is recommended for improved modeling of thermal processes and designing of bioreactors for thermal waste treatment.

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