MODEL AND METHOD OF CONTROLLED PYROLYSIS OF ORGANIC SUBSTANCES OF VARIABLE COMPOSITION

2021 ◽  
Vol 1 ◽  
pp. 134
Author(s):  
Konstantin V. Beglov ◽  
◽  
Alexander I. Brunetkin ◽  
Maxim M. Maximov ◽  
Elena O. Ulitskaya ◽  
...  

The issues of organization of the process of slow pyrolysis of organic substances, in the general case of unknown and variable composition, are considered. The relevance of the work is determined by considering the possibility of using various organic waste (domestic, agricultural, industrial) without their preliminary sorting and drying to obtain secondary energy resources of a known (controlled) composition. The novelty of the work is due to the development of a model for the method of controlled pyrolysis or gasification of organic substances with a minimum amount of solid residues at a maximum calorific value of the resulting mixture of combustible gases. A process based on filtration combustion in superadiabatic mode is considered. In existing devices, when this mode is implemented, a counter flow of the feedstock and reaction products is organized. As a result, a part of the water vapor generated at the drying stage is part of the mixture of reaction products and, accordingly, reduce their energy value. The scheme of the process proposed for consideration is based on the organization of the associated flow of feedstock and reaction products. As a result, the resulting carbon dioxide and water vapor are used as additional oxidizing agents. As a result, the carbonaceous residue decreases with a simultaneous increase in the composition of the mixture of gaseous products of carbon monoxide and hydrogen. A scheme for real-time monitoring of the composition of the feedstock during pyrolysis (gasification) is proposed. Knowledge of the composition makes it possible to control the process of its processing in order to: a) organize the optimal gasification process in terms of maximizing the amount and energy value of the mixture of gaseous reaction products; b) control the consumption of the processed feedstock in order to produce the required amount of product gas at any given time.

Author(s):  
Lazat Krebayeva ◽  
Zhannur Algabas ◽  
Akerkem Еssenbayeva ◽  
Alexandr Brodskyi ◽  
Sapargali Konuspayev

Cracking of paraffins was held to obtain long chain α-olefins using the catalysts from natural zeolite of Shankanay field modified with 1N HCl at the temperature range of 500-570°С and atmospheric pressure on a fixed layer. Liquid and gaseous reaction products were analyzed by gas chromatography; regeneration of the catalyst was carried out with a steam-air mixture until total absence of CO2 in the contact gases. To evaluate the structure and texture of the obtained catalysts, the methods of Mössbauer spectroscopy, X-Ray diffractometry analysis, and elemental analysis using scanning electron microscopy were used. As results, zeolite modification allowed doubling the activity of the catalysts and increasing the selectivity by 23.8-44.8%. The group compositions of olefins, alkanes and gaseous products were detected. Iron form under α-Fe2O3, ε-FeOOH and γ-FeOOH was present. The modified and blank form of catalysts under 1N hydrochloric acid solution washing phase content was detected; partial destruction of the crystalline carcass of clinoptilolite was observed.


2020 ◽  
Vol 22 (1) ◽  
pp. 3
Author(s):  
Y.V. Kraft ◽  
D.R. Nurmukhametov ◽  
B.P. Aduev ◽  
Z.R. Ismagilov

In this paper, one studied the effect of pulsed laser radiation (1064 nm, 120 μs) on lignite. The method of mass spectrometry was used to analyze the formed gaseous reaction products after the exposing of coal samples to the laser radiation. The pressed out of the pre-milled coal particles tablets were used as samples. In the mass spectra of the reaction products of laser radiation of the samples, the peaks with a mass to ion charge ratio m/z = 2, 18, 44 were detected, that corresponds to the main peaks of H2, H2O, and CO2 molecules. The pattern of formation of the end products CO2, H2, H2O when heating a sample of coal by laser radiation is proposed. The energy release factor is calculated, which is defined as the ratio of the calorific value, released during combustion of the sample to the dose of energy absorbed by the sample during irradiation.


2019 ◽  
Vol 5 (12) ◽  
pp. 37-46
Author(s):  
K. Chalov ◽  
Yu. Lugovoy ◽  
Yu. Kosivtsov ◽  
E. Sulman

This paper presents a study of the process of thermal degradation of crosslinked polyethylene. The kinetics of polymer decomposition was studied by thermogravimetry. Crosslinked polyethylene showed high heat resistance to temperatures of 400 °C. The temperature range of 430–500 °C was determined for the loss of the bulk of the sample. According to thermogravimetric data, the decomposition process proceeds in a single stage and includes a large number of fracture, cyclization, dehydrogenation, and other reactions. The process of pyrolysis of a crosslinked polymer in a stationary-bed metal reactor was investigated. The influence of the process temperature on the yield of solid, liquid, and gaseous pyrolysis products was investigated. The optimum process temperature was 500 °C. At this temperature, the yield of liquid and gaseous products was 85.0 and 12.5% (mass.), Respectively. Samples of crosslinked polyester decomposed almost completely. The amount of carbon–containing residue was 3.5% by weight of the feedstock. With increasing temperature, the yield of liquid products decreased slightly and the yield of gaseous products increased, but their total yield did not increase. For gaseous products, a qualitative and quantitative composition was determined. The main components of the pyrolysis gas were hydrocarbons C1–C4. The calorific value of pyrolysis gas obtained at a temperature of 500 °C was 17 MJ/m3. Thus, the pyrolysis process can be used to process crosslinked polyethylene wastes to produce liquid hydrocarbons and combustible gases.


2019 ◽  
Vol 38 (2) ◽  
pp. 406-416 ◽  
Author(s):  
Marcel Mikeska ◽  
Jan Najser ◽  
Václav Peer ◽  
Jaroslav Frantík ◽  
Jan Kielar

Gas from the gasification of pellets made from renewable sources of energy or from lower-quality fuels often contains a number of pollutants. This may cause technical difficulties during the gas use in internal combustion gas engines used for energy and heat cogeneration. Therefore, an adequate system of gas cleaning must be selected. In line with such requirements, this paper focuses on the characterization and comparison of gases produced from different types of biomass during gasification. The biomass tested was wood, straw, and hay pellets. The paper gives a detailed description and evaluation of the measurements from a fix-bed gasifier for the properties of the produced gases, raw fuels, tar composition, and its particle content before and after the cleaning process. The results of elemental composition, net calorific value, moisture, and ash content show that the cleaned gases are suitable for internal combustion engine-based cogeneration systems, but unsuitable for gas turbines, where a different cleaning technology would be needed.


2018 ◽  
Vol 197 ◽  
pp. 09005
Author(s):  
Bregas Siswahjono Tatag Sembodo ◽  
Hary Sulistyo ◽  
Wahyudi Budi Sediawan ◽  
Mohammad Fahrurrozi

Corncobs are potentially processed into bio-oil through thermochemical liquefaction processes. It is difficult to construct kinetics models based on the compounds involved in the reaction. It would be made four kinetic models based on four reaction products, i.e., solids, bio-oil, gas and volatile products. The purposes of the study were to seek kinetics model of thermochemical liquefaction of corncobs in ethanol-water solution and to study the effect of ethanol concentration. The experiment of liquefaction processes of corncobs in ethanol-water solution using sodium carbonate catalyst was performed in the 150 ml autoclave equipped with a magnetic stirrer in the temperature up to 280°C. Four kinetic models were applied to predict the yield of four reaction product lumps. The calculation results were compared to the experimental data. Compared to the others, model 4 was the most realistic and closely matching to the experimental data. In model 4 the reaction mechanism was assumed that biomass (corncobs) first decomposed into bio-oil, followed by decomposition of bio-oil into volatile products reversibly and, finally, volatile products decomposed into gaseous products. The yield of bio-oil increased from 42.05% to 54.93% by increasing to ethanol concentration of 0% to 40%.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Aviwe Melapi ◽  
Sampson N. Mamphweli ◽  
David M. Katwire ◽  
Edson L. Meyer

The application of biomass gasification technology is very important in the sense that it helps to relieve the dwindling supply of natural gas from fossil fuels, and the desired product of its gasification process is syngas. This syngas is a mixture of CO and H2; however, by-products such as char, tar, soot, ash, and condensates are also produced. This study, therefore, investigated selected by-products recovered from the gasification process of pinewood chips with specific reference to their potential application in other areas when used as blends. Three samples of the gasification by-products were obtained from a downdraft biomass gasifier system and were characterized in terms of chemical and physical properties. FTIR analysis confirmed similar spectra in all char-resin blends. For fine carbon particles- (soot-) resin blends, almost the same functional groups as observed in char-resin blends appeared. In bomb calorimeter measurements, 70% resin/30% char blends gave highest calorific value, followed by 50% resin/50% soot blends with values of 35.23 MJ/kg and 34.75 MJ/kg consecutively. Provided these by-products meet certain criteria, they could be used in other areas such as varnishes, water purification, and wind turbine blades.


Author(s):  
Ivan R. Sigfrid ◽  
Ronald Whiddon ◽  
Marcus Alde´n ◽  
Jens Klingmann

The emission composition is measured for a prototype burner while varying the equivalence ratio in discrete portions of the burner. The burner is a three sector system, consisting of a separate igniter, pilot/stabilizer and main burner. The design allows for discrete control of equivalence ratio in each of the three sectors. The ignition sector, designated RPL (Rich-Pilot-Lean), operates from rich to lean equivalence values, and serves to ignite the pilot sector, which, in turn, stabilizes the main combustion sector. All three burner sections are premixed. The burner is operated at atmospheric pressure with inlet flows heated to 650 K (±8 K). Tests were performed for three gases: methane, a model syngas (10% CH4, 22.5% CO, 67.5% H2), and dilute syngas. The dilute gas includes sufficient nitrogen to lower the heating value to 15 MJ/m3. The model syngas and diluted syngas are representative of fuels produced by gasification process. The burner emissions, specifically, CO, CO2, O2 and NOx, are measured while holding the RPL equivalence value constant and varying the equivalence ratio of the pilot and main sectors. The equivalence ratios for pilot and main sectors are chosen such that the total burner equivalence ratios remain constant during a test sequence. The target total equivalence ratio for each gas is chosen such that all experiments should have the same flame temperature.


1930 ◽  
Vol 3 (3) ◽  
pp. 241-251 ◽  
Author(s):  
J. C. McLennan F.R.S. ◽  
J. V. S. Glass B.A.

This paper deals with the action of cathode rays on gases and gas mixtures. Methane, methane-oxygen mixtures, carbon monoxide and carbon monoxide-oxygen mixtures were examined. Methane gave small percentages of hydrogen and ethane. Methane and oxygen mixtures gave as gaseous products, carbon monoxide, carbon dioxide and hydrogen, the only other products being water and formic acid. The relative proportions of the products do not vary widely under a wide variation of conditions.The reaction was found to be of the first order with respect to pressure. The reaction rate increases linearly with the voltage up to a certain value, after which it becomes nearly independent of the voltage.The action of cathode rays on carbon monoxide produces carbon dioxide and a solid brown suboxide which is extremely soluble in water, and its composition corresponds to a formula (C3O)n. If the carbon monoxide is moist, no visible amount of solid or liquid is found and there is less carbon dioxide.Carbon monoxide-oxygen mixtures under the action of cathode rays form carbon dioxide. Presence of water vapor has a retarding effect on the reaction. For mixtures of the same composition the reaction rate is proportional to the total pressure. For dry mixtures the product increases with the carbon monoxide present; when moist it is much less, and independent of the carbon monoxide.


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