Contribution to the research and development of radiation chambers in steam reforming. Influence of selected parameters on main characteristic quantities

1991 ◽  
Vol 56 (4) ◽  
pp. 831-846 ◽  
Author(s):  
Petr Stehlík
Keyword(s):  
Carbon Dioxide ◽  
Mathematical Model ◽  
Carbon Monoxide ◽  
Steam Reforming ◽  
Outer Surface ◽  
Flue Gas ◽  
Chemical Processes ◽  
Flue Gases ◽  
Maximum Temperature ◽  
Outlet Temperature

By means of a mathematical model simulating thermal chemical processes taking place in primary reformer radiation chamber, the influence of selected parameters on main characteristic quantities in steam reforming process was investigated. The parameters were divided into inlet parameters on flue gas side, inlet parameters on reaction mixture side and those of radiation chamber geometry. As main characteristic quantities outlet temperature of reaction mixture, maximum temperature of reaction tubes outer surface, outlet temperature of flue gases, absorbed heat, methane conversion into carbon dioxide and carbon monoxide as well as temperature distance from equilibrium were chosen.

Contribution to the Research and Development of Radiation Chambers in Steam Reforming. Problem-Oriented Application of a Fuzzy Expert System

1992 ◽  
Vol 57 (10) ◽  
pp. 2125-2134 ◽  
Author(s):  
Petr Stehlík ◽  
František Babinec
Keyword(s):  
Carbon Dioxide ◽  
Mathematical Model ◽  
Expert System ◽  
Service Life ◽  
Research And Development ◽  
Steam Reforming ◽  
Methane Conversion ◽  
Chemical Processes ◽  
Fuzzy Expert System ◽  
Present Contribution

An application of a fuzzy expert system intended for estimating some parameters of steam reforming can also be one of the examples of an ever increasing utilization of expert systems in practice. The present contribution deals with the method making use of a verified mathematical model for simulating thermal chemical processes in reforming furnace radiation chamber in order to create knowledge base. This base includes linguistic values of selected independent and dependent variable quantities. Examples given illustrate an evaluation of dependent variable quantities (methane conversion into carbon dioxide and monoxide, reaction tube service life) by means of the said expert system based on queries.

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

scholarly journals Influence of moisture content of combusted wood on the thermal efficiency of a boiler

2017 ◽  
Vol 38 (1) ◽  
pp. 63-74 ◽  
Author(s):  
Ladislav Dzurenda ◽  
Adrián Banski
Keyword(s):  
Carbon Monoxide ◽  
Moisture Content ◽  
Flue Gas ◽  
Thermal Efficiency ◽  
Heat Losses ◽  
Flue Gases ◽  
Heat Power ◽  
Emission Standards ◽  
Negative Effect ◽  
Gas Loss

Abstract In the paper the influence of moisture content of wood on the heat losses and thermal efficiency of a boiler is analysed. The moisture content of wood has a negative effect, especially on flue gas loss. The mathematical dependence of the thermal efficiency of a boiler is presented for the following boundary conditions: the moisture content of wood 10-60%, range of temperatures of emitted flue gases from the boiler into the atmosphere 120-200 C, the emissions meeting the emission standards: carbon monoxide 250 mgm−3, fly ash 50 mgm−3 and the heat power range 30-100%.

scholarly journals Modified Fly Ash-Based Adsorbents (MFA) for Mercury and Carbon Dioxide Removal from Coal-Fired Flue Gases

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7101
Author(s):  
Marta Marczak-Grzesik ◽  
Piotr Piersa ◽  
Mateusz Karczewski ◽  
Szymon Szufa ◽  
Hilal Ünyay ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Particle Size ◽  
Fly Ash ◽  
Chemical Composition ◽  
Solid Waste ◽  
Flue Gas ◽  
Flue Gases ◽  
Co2 Removal ◽  
Fly Ashes ◽  
Modified Fly Ash

One of the solid waste produced during the combustion of coal are fly ashes. Disposal challenges and environmental consequences are the results of significant process yield and atmospheric emission of fly ashes. The exact chemical composition of FA depends mainly on the type of utilised fuel and combustion conditions. It consists mainly of chemically stable metal oxides, such as Al2O3, Fe2O3, SiO2, CaO, MgO, K2O, Na2O and TiO2, but its toxicity is related to the possible presence of some trace elements, such as As, Hg, Cd, Se and Cr. The chemical and physical properties of fly ash (e.g., particle size distribution, porosity, and surface area) make it suitable as an adsorbent to remove various impurities from process flows such as flue gas stream. Its suitability for capturing mercury from flue gas was experimentally confirmed due to its abundant supply, particle size, bulk density, porosity, chemical composition and low cost. Hence, the use of fly ash as adsorbents and precursors for the production of heavy metal adsorbents is of great practical importance, as it reduces the cost of mercury capture and alleviates the problems associated with the disposal of solid waste. Studies showed that the chemical components present in fly ash additives could stimulate catalytic oxidative capacity, which increases the adsorption of Hg0 oxidation and adsorption of both Hg and CO2. The presented study analysed fly ashes from different zones of the electrostatic precipitator and verified their suitability for removing impurities from flue gases, i.e., mercury and carbon dioxide. The results outlined modified fly ash as having good Hg and CO2 removal capabilities. The adsorption efficiency of Hg reached 92% for Hg and 66% for CO2, while untreated fly ash reached 67% for Hg and 59% for CO2.

scholarly journals Defining of criteria for flue gas decarbonization efficiency in methanation reactors with membrane technology

2021 ◽  
Vol 286 ◽  
pp. 02014
Author(s):  
Gheorghe Lăzăroiu ◽  
Lucian Mihăescu ◽  
Dana-Alexandra Ciupăgeanu ◽  
Rodica-Manuela Grigoriu ◽  
Dana-Andreya Bondrea
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Flue Gas ◽  
Internal Combustion Engines ◽  
Carbon Tax ◽  
Thermal Power ◽  
Point Of View ◽  
Flue Gases ◽  
Economic Point ◽  
Practical Applications

The paper presents an investigation on the conditions for implementing a methanation membrane decarbonator coupled to an energy installation that generates flue gases. The retention of the carbon dioxide content in the flue gases and its conversion to methane is envisaged. For start, low thermal power installations, employing natural gas as main fuel supply, are considered. Internal combustion engines (also working with natural gas fuel) are taken into account for the testing of the carbon dioxide retention process. For this, a classification of the flue gas composition by fuel categories is initially carried out. The decarbonation efficiency is defined and clarifications are made withal regarding the connection between the decarbonation installation and the energy plant. The first practical achievements are also presented, resulting from a decarbonator with a volume of 940 cm3 (having the inner diameter of 12 cm and a height of 50 cm). The results prove that the proposed solution has great potential for practical applications, further research being however necessary. In terms of operating costs (including hydrogen consumption), it is remarked that they can be reduced by exploiting the methane production and eliminating the carbon tax, extending the integration perspective form economic point of view.

scholarly journals Dynamic Model of a Transcritical CO2 Heat Pump for Residential Water Heating

2021 ◽  
Vol 13 (6) ◽  
pp. 3464
Author(s):  
Hélio A. G. Diniz ◽  
Tiago F. Paulino ◽  
Juan J. G. Pabon ◽  
Antônio A. T. Maia ◽  
Raphael N. Oliveira
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
Mathematical Model ◽  
Steady State ◽  
Mass Flow Rate ◽  
Heat Pump ◽  
Mass Flow ◽  
Flow Rate ◽  
Outlet Temperature ◽  
Time Step

This paper presents a distributed mathematical model for a carbon dioxide direct expansion solar-assisted heat pump used to heat bath water. The main components are a gas cooler, a needle valve, an evaporator/collector, and a compressor. To develop the heat exchange models, mass, energy, and momentum balances were used. The model was validated for transient as well as steady state conditions using experimental data. A reasonably good agreement was observed between the predicted temperatures and experimental data. The simulations showed that the time step required to demonstrate the behavior of the heat pump in the transient regime is greater than the time step required for the steady state. The results obtained with the mathematical model revealed that a reduction in the water mass flow rate results in an increase in the water outlet temperature. In addition, when the carbon dioxide mass flow rate is reduced, the compressor inlet and outlet temperatures increase as well as the water outlet temperature.

scholarly journals Dependence of the boiler flue gas losses on humidity of wood biomass

2015 ◽  
Vol 36 (4) ◽  
pp. 77-86 ◽  
Author(s):  
Ladislav Dzurenda ◽  
Adrián Banski
Keyword(s):  
Adverse Effect ◽  
Heat Production ◽  
Flue Gas ◽  
Flue Gases ◽  
Outlet Temperature ◽  
Wood Biomass ◽  
Model Application ◽  
Mathematical Relation ◽  
Gas Loss

Abstract The paper analyzes the influence of humidity of combusted wood biomass on the flue gas losses. A mathematical relation between flue gas losses of the boiler on wood biomass humidity is presented as well as temperature of flue gas emitted from the boiler into the atmosphere. The limits of model application for the humidity of wood biomass falls into the interval 10–60% whereas the range of temperatures of flue gases emitted from the boiler to the atmosphere is 120–200 °C. The influence of the humidity of wood biomass has an adverse effect on increasing the extent of the boiler flue gas losses and thus inefficiency of the heat production. The increase of the wood biomass humidity from the value of 10% to 60% with the outlet temperature of flue gases from the boiler 120 °C causes an increase in flue gas loss of the boiler from the value 8.37% to 12.43%, similarly the increase of flue gas loss by 200 °C from 15.19% to 22.55%, or the increase of the flue gas loss by 7.36%.

scholarly journals Investigation of a combined gas-steam system with flue gas recirculation

2016 ◽  
Vol 37 (2) ◽  
pp. 305-316 ◽  
Author(s):  
Tadeusz Chmielniak ◽  
Paweł Mońka ◽  
Paweł Pilarz
Keyword(s):  
Carbon Dioxide ◽  
Flue Gas ◽  
Heat Recovery ◽  
Carbon Dioxide Concentration ◽  
Flue Gases ◽  
Heat Recovery Boiler ◽  
Gas Temperature ◽  
Flue Gas Recirculation ◽  
Recovery Boiler ◽  
Gas Recirculation

Abstract This article presents changes in the operating parameters of a combined gas-steam cycle with a CO2 capture installation and flue gas recirculation. Parametric equations are solved in a purpose-built mathematical model of the system using the Ebsilon Professional code. Recirculated flue gases from the heat recovery boiler outlet, after being cooled and dried, are fed together with primary air into the mixer and then into the gas turbine compressor. This leads to an increase in carbon dioxide concentration in the flue gases fed into the CO2 capture installation from 7.12 to 15.7%. As a consequence, there is a reduction in the demand for heat in the form of steam extracted from the turbine for the amine solution regeneration in the CO2 capture reactor. In addition, the flue gas recirculation involves a rise in the flue gas temperature (by 18 K) at the heat recovery boiler inlet and makes it possible to produce more steam. These changes contribute to an increase in net electricity generation efficiency by 1%. The proposed model and the obtained results of numerical simulations are useful in the analysis of combined gas-steam cycles integrated with carbon dioxide separation from flue gases.

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