The effects of calcium hydroxide on hydrogen chloride emission characteristics during a simulated densified refuse-derived fuel combustion process

This paper details the experimental and numerical analysis of a combustion process for atmospheric swirl burners using methane with added ammonia as fuel. The research was carried out for lean methane–air mixtures, which were doped with ammonia up to 5% and preheated up to 473 K. A flow with internal recirculation was induced by burners with different outflow angles from swirling blades, 30° and 50°, where tested equivalence ratio was 0.71. The NO and CO distribution profiles on specified axial positions of the combustor and the overall emission levels at the combustor outlet were measured and compared to a modelled outcome. The highest values of the NO emissions were collected for 5% NH3 and 50° (1950 ppmv), while a reduction to 1585 ppmv was observed at 30°. The doubling of the firing rates from 15 kW up to 30 kW did not have any great influence on the overall emissions. The emission trend lines were not proportional to the raising share of the ammonia in the fuel. 3D numerical tests and a kinetic study with a reactor network showed that the NO outlet concentration for swirl flame depended on the recirculation ratio, residence time, wall temperature, and the mechanism used. Those parameters need to be carefully defined in order to get highly accurate NO predictions—both for 3D simulations and simplified reactor-based models.

Download Full-text

Co-Combustion Studies of Low-Rank Coal and Refuse-Derived Fuel: Performance and Reaction Kinetics

Energies ◽

10.3390/en14133796 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3796

Author(s):

Mudassar Azam ◽

Asma Ashraf ◽

Saman Setoodeh Setoodeh Jahromy ◽

Sajjad Miran ◽

Nadeem Raza ◽

...

Keyword(s):

Activation Energy ◽

Waste Management ◽

Energy Demand ◽

Power Plants ◽

Combustion Process ◽

Isoconversional Methods ◽

Low Rank ◽

Heating Rates ◽

Average Activation Energy ◽

Refuse Derived Fuel

In connection to present energy demand and waste management crisis in Pakistan, refuse-derived fuel (RDF) is gaining importance as a potential co-fuel for existing coal fired power plants. This research focuses on the co-combustion of low-quality local coal with RDF as a mean to reduce environmental issues in terms of waste management strategy. The combustion characteristics and kinetics of coal, RDF, and their blends were experimentally investigated in a micro-thermal gravimetric analyzer at four heating rates of 10, 20, 30, and 40 °C/min to ramp the temperature from 25 to 1000 °C. The mass percentages of RDF in the coal blends were 10%, 20%, 30%, and 40%, respectively. The results show that as the RDF in blends increases, the reactivity of the blends increases, resulting in lower ignition temperatures and a shift in peak and burnout temperatures to a lower temperature zone. This indicates that there was certain interaction during the combustion process of coal and RDF. The activation energies of the samples were calculated using kinetic analysis based on Kissinger–Akahira–Sunnose (KAS) and Flynn–Wall–Ozawa (FWO), isoconversional methods. Both of the methods have produced closer results with average activation energy between 95–121 kJ/mol. With a 30% refuse-derived fuel proportion, the average activation energy of blends hit a minimum value of 95 kJ/mol by KAS method and 103 kJ/mol by FWO method.

Download Full-text

Experimental Investigation of Hydrogen Chloride Bonding with Calcium Hydroxide in the Furnace of a Stoker-Fired Boiler

Energy & Fuels ◽

10.1021/ef901534d ◽

2010 ◽

Vol 24 (3) ◽

pp. 1948-1957 ◽

Cited By ~ 7

Author(s):

Sławomir Poskrobko ◽

Jan Łach ◽

Danuta Król

Keyword(s):

Experimental Investigation ◽

Calcium Hydroxide ◽

Hydrogen Chloride

Download Full-text

A Numerical Study on the Combustion Process and Emission Characteristics of a Natural Gas-Diesel Dual-Fuel Marine Engine at Full Load

Energies ◽

10.3390/en14051342 ◽

2021 ◽

Vol 14 (5) ◽

pp. 1342

Author(s):

Van Chien Pham ◽

Jae-Hyuk Choi ◽

Beom-Seok Rho ◽

Jun-Soo Kim ◽

Kyunam Park ◽

...

Keyword(s):

Natural Gas ◽

Combustion Process ◽

Simulation Software ◽

Dual Fuel ◽

Injection Timing ◽

Emission Characteristics ◽

Cylinder Pressure ◽

Marine Engine ◽

Full Load ◽

Simulation Results

This paper presents research on the combustion and emission characteristics of a four-stroke Natural gas–Diesel dual-fuel marine engine at full load. The AVL FIRE R2018a (AVL List GmbH, Graz, Austria) simulation software was used to conduct three-dimensional simulations of the combustion process and emission formations inside the engine cylinder in both diesel and dual-fuel mode to analyze the in-cylinder pressure, temperature, and emission characteristics. The simulation results were then compared and showed a good agreement with the measured values reported in the engine’s shop test technical data. The simulation results showed reductions in the in-cylinder pressure and temperature peaks by 1.7% and 6.75%, while NO, soot, CO, and CO2 emissions were reduced up to 96%, 96%, 86%, and 15.9%, respectively, in the dual-fuel mode in comparison with the diesel mode. The results also show better and more uniform combustion at the late stage of the combustions inside the cylinder when operating the engine in the dual-fuel mode. Analyzing the emission characteristics and the engine performance when the injection timing varies shows that, operating the engine in the dual-fuel mode with an injection timing of 12 crank angle degrees before the top dead center is the best solution to reduce emissions while keeping the optimal engine power.

Download Full-text

Effect of Engine Operating Parameters on Combustion and Emission Characteristics

ASME 1992 International Computers in Engineering Conference: Volume 1 — Artificial Intelligence; Expert Systems; CAD/CAM/CAE; Computers in Fluid Mechanics/Thermal Systems ◽

10.1115/cie1992-0080 ◽

1992 ◽

Author(s):

Jiang Lu ◽

Ashwani K. Gupta ◽

Eugene L. Keating

Keyword(s):

Internal Combustion Engine ◽

Combustion Chamber ◽

Internal Combustion Engines ◽

Combustion Engine ◽

Combustion Process ◽

Pressure Rise ◽

Internal Combustion ◽

Operating Parameters ◽

Emission Characteristics ◽

Pollutants Emission

Abstract Numerical simulation of flow, combustion, heat release rate and pollutants emission characteristics have been obtained using a single cylinder internal combustion engine operating with propane as the fuel. The data are compared with experimental results and show excellent agreement for peak pressure and the rate of pressure rise as a function of crank angle. The results obtained for NO and CO are also found to be in good agreement and are similar to those reported in the literature for the chosen combustion chamber geometry. The results have shown that both the combustion chamber geometry and engine operating parameters affects the flame growth within the combustion chamber which subsequently affects the pollutants emission levels. The code employed the time marching procedure and solves the governing partial differential equations of multi-component chemically reacting fluid flow by finite difference method. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.

Download Full-text

SPECTRAL DIAGNOSTICS OF THE HYDROCARBON FUEL COMBUSTION PROCESS

Kontrol Diagnostika ◽

10.14489/td.2021.10.pp.012-017 ◽

2021 ◽

pp. 12-17

Author(s):

M. A. Vaganov

Keyword(s):

Combustion Process ◽

Hydrocarbon Fuel ◽

Combustion Products ◽

Combustible Mixture ◽

Fuel Combustion ◽

Propane Combustion ◽

Gaseous Hydrocarbon ◽

Spectral Bands ◽

Air Supply ◽

Spectral Diagnostics

It is proposed to use the methods of applied optical spectroscopy to solve the problem of control and diagnostics of gaseous hydrocarbon fuel combustion in this work. The results of an experimental study of spectroscopic informative parameters characterizing the propane combustion process are presented for three modes: combustion of pure propane without air supply, stoichiometric combustion and combustion with a change in the amount of supplied air relative to stoichiometric combustion. As a result of the experiment, it was found that the most intense bands in the emission spectrum of the flame arising from the combustion of propane correspond to the spectral bands of radicals of combustion products: OH, CH, and C2. While the intensities of various systems of bands in the flame spectrum depend significantly on the composition of the combustible mixture.

Download Full-text