scholarly journals Experimental studies of intermediate pyrolysis of woody and agricultural biomass in a fixed bed reactor

2021 ◽  
Vol 323 ◽  
pp. 00003
Author(s):  
Artur Bieniek ◽  
Wojciech Jerzak ◽  
Aneta Magdziarz

Biomass pyrolysis is an advanced process which leads to obtaining products as chars, primary tars and gases. Depending on pyrolysis conditions and reactor construction, the pyrolysis could be divided into three categories: slow, intermediate and fast. This work concerns the experimental analysis of an intermediate pyrolysis of biomass residues in a fixed bed reactor. As raw materials, pine bark and wheat straw were selected. Experiments were carried out at three temperatures: 400, 500 and 600 °C under constant volume flow rate of inert gas equal to 100 ml/min. Biomass samples were kept for 150 seconds in the hot zone. The main goal was to compare yields, elemental composition, and calorific values of received products under studied process conditions. The ultimate analysis of chars and organic fractions of oils was performed. Obtained results from ultimate analysis allowed to determine higher heating values by a theoretical correlation. The products of pyrolysis obtained at 600 °C characterized by the most energetic parameters. The higher heating value for organic fraction of tars was 31.62 MJ/kg while for char was 29.47 MJ/kg.

2014 ◽  
Vol 16 (2-3) ◽  
pp. 209 ◽  
Author(s):  
A. Diéguez-Alonso ◽  
A. Anca-Couce ◽  
F. Behrendt

<p>Consolidated industrial application of biomass thermochemical conversion processes, such as pyrolysis and gasification, requires the development and application of control and optimization techniques. To this end, on-line process characterization, regarding mainly product distribution and composition under similar conditions as the ones encountered in industrial applications is needed. In the present study, slow pyrolysis and updraft gasification of thermally thick particles in a technical scale fixed-bed reactor are carried out under several process conditions. Different raw materials are used: pine wood chips, beech-wood spheres and cellulose. In pyrolysis, the increasing influence of transport phenomena in the conversion process due to the use of a technical-scale reactor and thermally thick wood particles is analysed through the temperature distribution inside the bed during the process together with the char properties characterization taken from four different positions inside the bed. The influence of process conditions, such as the N<sub>2</sub> flow rate, on the products composition and distribution is also analysed. In gasification, the influence of the air to fuel ratio on the product gas composition is characterized, as well as the qualitative evolution of polycyclic aromatic hydrocarbons (PAH) representative species in the volatiles vapours by applying laser-induced fluorescence (LIF).</p>


Author(s):  
Funda Ates¸

In this study, corncob was chosen as a biomass sample and the pyrolysis of this sample was carried out with or without catalyst at different conditions in a well-swept fixed-bed reactor. In the experimental studies, firstly the raw material was analysed for its moisture, ash, volatile matter and fixed carbon. Then, experiments were conducted with a heating rate of 700 °C/min, mean particle size and between 300–800 °C pyrolysis temperatures with or without catalyst. The catalytic experiments involved a dry mixing of the catalyst with the biomass using an in bed-mode in the nitrogen atmosphere. In the experimental studies, influence of catalyst and temperature on the corncob products was investigated. According to the experimental results; maximum bio-oil yield was obtained as 36.1% and 34.8% with or without catalyst at a pyrolysis temperature of 500°C, respectively. The use of catalyst showed its cracking effect at higher temperatures and the gas yield increased above pyrolysis temperature of 500 °C. Pyrolysis oils were examined by using elemental analysis and GC/MS. According to all results; the use of catalyst can be suggested in the pyrolysis to obtain both good quality fuels and valuable chemicals.


2013 ◽  
Vol 773 ◽  
pp. 445-449
Author(s):  
Jian Zhao Qin ◽  
Fang Fang Shan ◽  
Yao Qing Chen

The synthesis of hexafluoropropylene oxide in fixed-bed reactor using HFP as raw materials and molecular oxygen as oxidant is studied in the present paper. The selectivity of HFPO on the Ag/γ-Al2O3 catalyst prepared by impregnation can get 41.8%. The influence of the Ag/γ-Al2O3 catalyst modified by impregnation-sedimentation method and first group metal salts on synthesis reaction was investigated, as well as process conditions.


1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.


2013 ◽  
Vol 873 ◽  
pp. 562-566 ◽  
Author(s):  
Juan Liu ◽  
Xia Li ◽  
Qing Jie Guo

Chlorella samples were pyrolysed in a fixed bed reactor with γ-Al2O3 or ZSM-5 molecular sieve catalyst at 600°C. Liquid oil samples was collected from pyrolysis experiments in a condenser and characterized for water content, kinematic viscosity and heating value. In the presence of catalysts , gas yield decreased and liquid yield increased when compared with non-catalytic pyrolysis at the same temperatures. Moreover, pyrolysis oil from catalytic with γ-Al2O3 runs carries lower water content and lower viscosity and higher heating value. Comparison of two catalytic products, the results were showed that γ-Al2O3 has a higher activity than that of ZSM-5 molecular sieve. The acidity distribution in these samples has been measured by t.p.d, of ammonia, the γ-Al2O3 shows a lower acidity. The γ-Al2O3 catalyst shows promise for production of high-quality bio-oil from algae via the catalytic pyrolysis.


2018 ◽  
Vol 388 ◽  
pp. 44-60
Author(s):  
Mojtaba Mirzaei ◽  
Mohammad Hossein Ahmadi ◽  
Mahyar Ghazvini ◽  
Ehsan Sobhani ◽  
Giulio Lorenzini ◽  
...  

The expenses, which caused by pollution and limited fossil resources, have convinced scientists to concentrate on renewable resources such as biological waste. Conversion of bio-waste to syntheses gas produces higher heating values in comparison to conventional bioenergy production methods. To produce energy from bio waste, it is important to study on existing technology and using CHP and gas turbines. In this paper a plan for producing electricity and heat at the same time by using bio waste has been proposed. This plan provides a method to produce hybrid gas (combined gas) by using solid bio-waste of Tehran in two forms of wet and dry as a renewable energy resource and steam in a fixed bed gas reactor. This gas is a combination of Hydrogen, Carbon monoxide, Carbon dioxide Water and some amount of Methane. Selected temperature and pressure for the reactor respectively is1900 [˚F] and 390 [Psi]. As indicated in the results, the best air and steam combination entering fixed bed reactor among 60 different combinations for dry waste is 0.2% of entering fuel volume for steam 0.25% of entering fuel volume for air heating value for this combination is 6471 [BTU/lb]. Furthermore, for the steam volumes of 1.5% to 0.9%, the percentage of H2 in the syngas increases by enhancing the volume of air content.


2011 ◽  
Vol 393-395 ◽  
pp. 1212-1216 ◽  
Author(s):  
Huan Wang ◽  
Yong Fa Diao

As to figure out the effect that modified fly ash, which is prepared by fly ash –CaO, and modified fly ash dust layer attached on the surface of the filter material adsorbed elemental mercury, experimental studies are administrated in a laboratory-scale fixed bed reactor system with gaseous elemental mercury produced by a mercury vapor generator and simulated flue gas composition. The experimental results indicated that the adsorption performance of fly ash and CaO relatively poor. The proportion of CaO in the modified fly ash will affected the mercury removal efficiency of the absorbent which prepared by fly ash and CaO. It will be an optimal effect when the blend ratio of the flying ash and CaO is 2 to 1, and the maximum removal efficiency is up to 34%.As the adsorption temperature increases the removal efficiency of the modified fly ash deteriorates. The efficiency of dust layer attaching on the surface of the filter material is getting higher with the larger porosity of dust layer and smaller particle material size.


2015 ◽  
Vol 787 ◽  
pp. 67-71
Author(s):  
R.M. Alagu ◽  
E. Ganapathy Sundaram

Pyrolysis process in a fixed bed reactor was performed to derive pyrolytic oil from groundnut shell. Experiments were conducted with different operating parameters to establish optimum conditions with respect to maximum pyrolytic oil yield. Pyrolysis process was carried out without catalyst (thermal pyrolysis) and with catalyst (catalytic pyrolysis). The Kaolin is used as a catalyst for this study. The maximum pyrolytic oil yield (39%wt) was obtained at 450°C temperature for 1.18- 2.36 mm of particle size and heating rate of 60°C/min. The properties of pyrolytic oil obtained by thermal and catalytic pyrolysis were characterized through Fourier Transform Infrared Spectroscopy (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS) techniques to identify the functional groups and chemical components present in the pyrolytic oil. The study found that catalytic pyrolysis produce more pyrolytic oil yield and improve the pH value, viscosity and calorific value of the pyrolytic oil as compared to thermal pyrolysis.


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