Experimental Studies and the Chemical Kinetics Modelling of Oxidation of Hydrogen Sulfide Contained in Biogas

AbstractThis paper presents the results of experimental and numerical research on the process of biogas air combustion. The purpose of the study was to determine the effect of biogas CO2 content on: (a) variations in SO2 concentrations in flue gas, (b) variations in the rates of the key reactions of oxidation of H2S to SO2.The subject of investigation were the gas mixtures: CH4/CO2 (of 25; 35 and 45 vol % CO2) with a varying hydrogen sulfide content. The experiments were conducted in a three-zone pipe furnace equipped with a swirl burner (Sg=1.26) with combustion substrate pre-mixing. It was noticed that the consumption of hydrogen sulfide was significantly reduced with the temperature decrease from 1223 K to 1023 K. The increase in the biogas carbon dioxide content inhibited the process of oxidation of H2S to SO2

THE INFLUENCE OF TEMPERATURE AND THE RATIO OF AIR EXCESS ON COMBUSTION EFFICIENCY OF POLYOLEFIN MATERIALS

Combustion of plastics is a very complex process and phenomena, which occur during this process, have not been sufficiently investigated. Polyolefins constitute almost half of all the generated plastics. In this study, the influence of temperature and the ratio of air excess on the concentration of pollutants in flue gases have been presented. The studies carried out on the designed test bench were preceded by a series of thermal analyses (TG, DSC, TG-MS)

Analiza parametrów termicznych i chemicznych procesu spalania odpadów termoplastycznych : praca doktorska /

Recenzenci pracy: Andrzej Buczek, Krzysztof Pielichowski.Praca doktorska. Akademia Górniczo-Hutnicza im. Stanisława Staszica (Kraków), 2008.Bibliogr. k. 108-114.Podział tworzyw sztucznych, metody otrzymywania poliolefin, polimeryzacja polietylenu, polipropylenu, charakterystyka środków pomocniczych, właściwości i zastosowanie tworzyw poliolefinowych, utylizacja odpadów z tworzyw sztucznych (OTS) w przemyśle ciężkim, wykorzystanie tworzyw sztucznych w przemyśle metalurgicznym, charakterystyka procesu wielkopiecowego, redukcja tlenków żelaza, zastosowanie odpadów z tworzyw sztucznych w hutnictwie światowym, wykorzystanie tworzyw sztucznych w energetyce, prawne, środowiskowe aspekty zastosowania OTS, przebieg procesu spalania tworzyw sztucznych, mechanizm spalania termoplastów, termiczna degradacja poliolefin, spalanie węglowodorów, przegląd badań prowadzonych nad produktami spalania wybranych tworzyw sztucznych, analiza termiczna, spektroskopowa, metody analizy termicznej, termograwimetria, TG, różnicowa kalorymetria skaningowa, DSC, termiczna analiza różnicowa, DTA, metody spektroskopowe, spektrometria masowa, MS, spektroskopia w podczerwieni z transformacją Fourier’a, FT-IR, analiza badanych materiałów, charakterystyka próbek, metodyka przeprowadzonych analiz, analiza elementarna, TG-MS, badania na stanowisku laboratoryjnym, charakterystyka spalanych materiałów poliolefinowych, polietylen małej gęstości Malen E FGAN 18-D003, dużej gęstości Hostalen ACP 5831 D, Polipropylen Moplen HP548R, analiza pomiarów temperatury, stężeń produktów spalania w gazach odlotowych, analiza kinetyczna termicznej degradacji poliolefin w atmosferze utleniającej, model kinetyki, analiza kinetyczna PE-LD, PE-HD, P

Speciation of inorganic gaseous species and condensed phases during coconut husk combustion based on thermodynamic equilibrium calculations

Thermodynamic equilibrium calculations to predict coconut husks (CH) combustion products have been carried out in this work. The selected type of biomass belongs to problematic fuels due to the fibrous structure preventing its grinding, and high chlorine content. The calculations results showed, that the combustion temperature for the tested range of 600-1000°C clearly affects the concentrations of chlorine species in the flue gas. When the temperature was below 820°C, the highest concentration had HCl(g), and above 820°C KCl(g). The chlorine was also present in ash, as KCl-NaCl-RbCl solid solution, when the combustion temperature T <700°C, and KCl-NaCl-K2SO4-Na2SO4 liquid solution, when 600 <T <960 °C. High content of chlorine in ash from CH combustion at T = 650°C has been confirmed experimentally. Speciations of inorganic gaseous species and condensed phases we investigated also during flue gas cooling from 1000 to 400°C. Major condensed phase composition were dominated by alkali metal salts in both solid and liquid phase states. Finally, we presented sixteen eutectic points for different binary systems calculated in the FactSage software

Thermal degradation of waste polyolefines and their application in blast-furnace process

Tyt. z nagłówka.Bibliografia s. 123.Dostępny również w formie drukowanej.ABSTRACT: Nowadays about 60% of world production and consumption of plastics are polyolefines. They are used as packaging, in building engineering, automotive industry or electronic engineering. High calorific value and proper Chemical composition of polyolefines (based on carbon and hydrogen) make them ideal for use in a wide range of applications. The polyolefines can be used as a substitute for coke in blast-furnace processes. This paper outlines thermal decomposition of PE-LD, PE-HD, PP which are used in agriculture and packaging from household. Thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) were used as analytical methods. KEYWORDS: blast furnace, co-combustion, thermal analysis, waste polyolefines. STRESZCZENIE: Obecnie około 60% światowej produkcji i konsumpcji tworzyw sztucznych stanowią poliolefiny. Znajdują one zastosowanie w produkcji opakowań, w budownictwie, w przemyśle samochodowym oraz przemyśle elektronicznym. Wysoka wartość opałowa oraz skład chemiczny poliolefin (oparty na węglu i wodorze) sprawiają, że po wykorzystaniu mogą być stosowane w szerokim zakresie. Poliolefiny mogą być stosowane m.in. jako substytut koksu w procesie wielkopiecowym. Artykuł przedstawia rozkład termiczny PE-LD, PE-HD oraz PP pochodzących z rolnictwa, opakowalnictwa i z gospodarstwa domowego. Jako metody analityczne zastosowano: termograwimetrię (TG) i różnicową kalorymetrię skaningową (DSC). SŁOWA KLUCZOWE: wielki piec, współspalanie, analiza termiczna, odpady poliolefinowe

Syngas as a Reburning Fuel for Natural Gas Combustion

The paper aims to confirm the syngas application as a reburning fuel to reduce e.g. NO emission during natural gas combustion. The main aim of this modelling work was to predict pollutants generated in the exhaust gases and to indicate the influence of the syngas on the natural gas combustion process. The effect of residence time of fuel-air mixture was also been performed. Calculations were made with CHEMIKN-PRO for reburning process using syngas. The boundary conditions of the reburning process were based on experimental investigations. The addition of 5, 10, 15 and 19% of reburning fuel into natural gas combustion was studied. The effects of 0.001 to 10 s of residence time and the addition of 5, 10, and 15% of syngas on combustion products were determined. The performed numerical tests confirmed that co-combustion of the natural gas with syngas (obtained from sewage sludge gasification) in the reburning process is an efficient method of NOx reduction by c.a. 50%. Syngas produced from sewage sludge can be utilised as a reburning fuel

CHEMICAL ANALYSIS OF REFRACTORY MATERIALS BY SEM TECHNIQUE

In the Polish industry, especially in the iron and steel industry, uses large amounts of refractory materials. Waste materials are disposed of through a common storage. For alternative methods of waste management of refractory materials, it is necessary to carry out several studies. One of the basic research include determine the chemical composition of refractory materials exposed to liquid steel. This paper presents the results of microscopic examination of changes in the concentration of refractory elements in new and used

THE REDUCTION OF THE EMISSION OF NOx IN THE HEAT-TREATING FURNACES

Despite the fossil fuel are still dominant source of primary energy in the word, the natural gas is generally used in many branches in industry. The interest in natural gas is caused by new production technologies (shale gas). This situation leads to take an interest in natural gas combustion technologies, especially low-emission combustion. In spite of many advantages of natural gas, it is also a source of nitrogen oxides generated during combustion in high temperature processes. The knowledge of the mcchanisms of the formation of NOx allows to modify the combustion process. There are two ways of Iow emission combustion processes leading to reduce pollutants: "primary and secondary methods". This paper presents the primary low-emission combustion method using the recirculation of flue gas and air excess ratio

The Effect of Ash Silanization on the Selected Properties of Rigid Polyurethane Foam/Coal Fly Ash Composites

According to the assumptions of the European Union, by 2050 it is planned to achieve climate neutrality. For this purpose, a document called the “European Green Deal” was established, which is a set of policies of the European Commission. One of the assumptions is a circular economy that takes into account the use of waste in subsequent production cycles. In order to meet the latest trends in environmentally friendly materials and use of waste in the production of building materials, composites of rigid polyurethane foam with 10 wt.% of waste were produced. Fly ash from coal combustion after modification was used as a filler. Three types of modifications were used: silanization, sieving, and both processes together. The silanization process was carried out for 1 and 2% silane ([3-(2-aminoethylamino)propyl]trimethoxysilane) concentration in relation to the fly ash mass. The sieving was aimed at reaching a fraction with a particle diameter below 75 µm. Six composites with modified fillers were compared and one material containing unchanged fly ash was used as a reference. A comparative analysis was carried out on the basis of surface analysis, thermal stability and physical properties. It turned out that the polyurethane materials modified fly ash silanized with 1% and 2% silane solution proved the best results in performed tests. On the other hand, the polyurethane foam containing sieved ash was characterized by the lowest flammability and the lowest emission of smoke and CO. The use of modified fly ash in technology of polyurethane foams can be a good method of its disposal and can increase the applicability of the composites