Flue Gas Analyzer Research Articles

Mechanical properties, degradation and flue gas analysis of basalt and glass fiber reinforced recycled polypropylene

Abstract Fiber reinforced recycled polypropylene composites (FRRPC) are developed by reinforcing chopped basalt fiber (BF) and glass fiber (GF) in recycled polypropylene (RPP) using injection molding techniques. The composites are differentiated by varying the fiber volume at 10, 20 and 30 vol.-%. This investigation has been conducted to study the mechanical properties of FRRPC by means of tensile, flexural and impact tests. In addition to that, fracture surfaces have been cut and observed under a scanning electron microscope (SEM). Degradation processes were carried out to assess the amount of oxygen used by the bacteria to stabilize the organic matter under controlled conditions of time and temperature. Flue gas analysis revealings carbon monoxide(CO) and carbon dioxide (CO2), is within the allowable limit. From the above results, it became evident that basalt fiber reinforced polypropylene (BFRP) is superior to glass fiber reinforced polypropylene (GFRP).

Slagging and fouling characteristics during co-combustion of Scots pine bark with low-temperature dried pulp and paper mill chemical sludge

This paper shows how chemical sludge (CS) generated during wastewater treatment at a paperboard mill can be quickly dried at low-temperature and employed in bark-fired boilers to reduce slagging and corrosion problems. By using a cyclone-dryer operated at an inlet-air velocity of 110 m/s and a temperature of 90 °C, the dry-matter content of CS was increased from approximately 19 to 82%. The residence time of CS inside the cyclone was approximately 2 s when using the inlet-air velocity mentioned above. Disaggregation of the feedstock caused by collisions with the cyclone wall and between particles played a crucial role in enhancing the efficiency of heat and mass transfer. Three co-pelletized mixtures of Scots pine bark (SPB) and dried-CS were combusted in a 40 kW fixed-bed burner. Flue gas analysis was performed with a gas analyser. Coarse and fine ash were analysed by SEM-EDS and XRD. NOx and SO2 emissions increased with increasing amount of CS in the mixtures. Mono-combustion of SPB resulted in a large quantity of slag (i.e., molten ash) with a high degree of sintering (i.e., hardness of the slag), and ash deposits formed on heat transfer surfaces were rich in K2SO4 and KCl. Mixtures of SPB and CS were less prone to slagging, and the amount of alkali chloride in the deposits was reduced in favour of alkali sulphate formation.

PERFORMANCE OPTIMIZATION OF EXISTING BOILERS AT SHAKARGANJ LLIMITED, JHANG

There are numerous well-documented phenomena that plague the efficient operation of bagasse boilers. Key Parameters that influence boiler combustion and operation are studied with the aid of combustion and flue gas analyzer. Combustion stability and efficiency is linked to various parameters such as fuel moisture and air temperatures supplied to the boiler and are investigated in this paper as part of a case study. The paper highlights number of modern developments that have been implemented at Shakarganj Limited, Jhang to optimize the existing boiler design to enhance the Boiler capacity from 65 tph to 80 tph. Along with that impact of various devices on performance improvement of boiler has been shown with experimental data for comprehensive evaluation of boiler operation and combustion efficiency. Results of suitable measures after installation of low cost retrofits to reduce losses including combustion instabilities, unburnt fuel, moisture in fuel and deposition of ash on tubes are also part of the paper.

СОВМЕСТНОЕ КАТАЛИТИЧЕСКОЕ СЖИГАНИЕ САЖИ И ВОДОРОДА В КИПЯЩЕМ СЛОЕ

Актуальность исследования обусловлена необходимостью обезвреживания выбросов сажи и водорода из печей нанесения углеродных покрытий на сорбенты, которые в основном сжигаются в факельном режиме. Это приводит к образованию термических оксидов азота и не обеспечивает полного сгорания сажи. Цель: определение оптимальных условий проведения процесса совместного сжигания продуктов пиролиза бутадиена в кипящем слое катализатора глубокого окисления на реальных выбросах смеси сажи и водорода из печи нанесения углеродных покрытий на сорбенты. Объекты: реальные выбросы смеси сажи и водорода из печи нанесения углеродных покрытий на сорбенты. Методы: хроматографический анализ отходящих газов из реактора с кипящим слое катализатора при сжигании смеси сажи и водорода, фотоколориметрический анализ газов на содержание оксидов азота с использованием реактива Грисса–Илосвая, весовой метод определения выбросов сажи. Удельную поверхность сажи определяли на основе данных изотермы низкотемпературной адсорбции азота. Результаты. Определены оптимальные условия проведения процесса совместного сжигания продуктов пиролиза бутадиена в кипящем слое катализатора глубокого окисления на реальных выбросах смеси сажи и водорода из печи нанесения углеродных покрытий на сорбенты. Показано, что при совместном каталитическом сжигании сажи и водорода в кипящем слое промышленного катализатора ИК-12-70 происходит практически полное окисление водорода при температуре на уровне 550 °С, а степень выгорания углерода в виде сажи достигает значения не ниже 99,9 %. Выбросы вредных веществ незначительны: NOx – не более 4,5 мг/м3, CO – не более 0,037 об. %.

Simultaneous Removal of SO2 and NO Using H2O2/Urea Activated by Vacuum Ultraviolet Light in a Pilot-Scale Spraying Tower

A study on simultaneous removal of SO2 and NO from flue gas using H2O2/urea activated by vacuum ultraviolet (VUV) light was carried out in a pilot-scale photochemical spraying tower. The effects of different operational variables on simultaneous removal efficiencies of SO2 and NO were investigated. The gaseous and liquid removal products were detected by the flue gas analyzer and ion chromatography (IC), respectively. The removal pathways of SO2 and NO were analyzed. The application prospect of this new method was also preliminarily discussed. Results show that under most of the process conditions tested, SO2 can attain complete removal. Removal efficiency of NO is enhanced under increasing the VUV irradiation intensity and H2O2 concentration, but it is inhibited by an increase of the flue gas flow and NO concentration. The urea concentration and liquid–gas ratio have a dual influence on NO removal, and its removal efficiency increases first and then decreases. SO2 concentration has little impact on NO re...

Experimental Study of a Lab Scale Hybrid Fixed Bed Gasifier

Thermo-chemical conversion technologies (incineration, gasification and pyrolysis) have emerged as potential technologies for municipal solid waste management (MSWM). This is happening due to the increase of the need for clean and sustainable energy as a result of fossil fuel depletion. The increase in municipal solid waste (MSW) generation as well as land scarcity for MSW disposal is another reason in raising the potential for thermal technology. Incineration has been the most common thermo-chemical technology for solid waste disposal. However, due to environmental concern, gasification technology is currently becoming more preferable since it is environmental friendly for MSW disposal as well as energy recovery. The aim of this study is to analyze the flue gases obtained from the hybrid fixed bed gasifier during gasification of MSW. The fire was initiated by wood charcoal and six kilograms of MSW was fed in the gasifier. The combustion was supported by the air supplied by electric blower. The flue gas analyzer, TESTO 327-1 was used to analyze the concentration of CO, CO2 and O2. Results show that after 150 minutes of the gasification process, O2 concentration increased by 17.2% while CO and CO2 decreased by 0.0% and 3.77% respectively. The experimental results show that, during gasification process the O2 concentration was increasing with time while CO and CO2 concentration decreased.

The Research of a New Iteration of the Circular Algorithm

Abstract It is a problem of spectra analysis of flue gas that how to separate and calculate the concentration of different kinds of gas from continuous mixed gas absorption spectrum signal. So based on experimental data, a new iteration of the circular algorithm is put forward on the basis of Lambert-Beer’s law. The algorithm uses different UV-light wavelengths at 190nm-290nm for different characteristics of UV light with different absorption peaks. The iteration is repeated until the concentration difference between adjacent two gases is less than a certain value. It is considered that the elemental gas The exact concentration, and through the programming to achieve the results. it has strong anti-jamming capability and is suitable for practical application of engineering.

High-temperature pyrolysis behavior of a bituminous coal in a drop tube furnace and further characterization of the resultant char

In order to study the high-temperature pyrolysis behavior of bituminous coal in the drop tube furnace (DTF) and better utilization of the obtained char, a typical Shenhua bituminous coal (SH) was pyrolyzed in a DTF at the temperatures of 1000–1300 °C (100 °C increments). The obtained char was then characterized using BET and FTIR methods, while its combustion, gasification and pollutant emission characteristics were explored by a thermogravimetric analyzer and online flue gas analyzer. Results show that higher pyrolysis temperature leads to more CO and less CH4 for the increased free radical rearrangement by high heating rate and carbon reduction reactions at high temperatures. Pyrolysis generally decomposes the functional groups, increases the volume of char pores, and upgrades the rank of coal. The combustion activation energy increases from 22.99 kJ/mol to 27.42 kJ/mol and the gasification is hindered with the higher pyrolysis temperature. It is notable that the NOx and SO2 emissions of the obtained char combustion are both below 30 mg/s-MJ. High-temperature pyrolysis can enhance the evolution of NH3 and HCN as volatiles, thus decreasing the NOx formation in further char combustion stages while partly decomposing the organic and inorganic sulfur compounds to impact the SO2 emission.

Experimental characterizing combustion emissions and thermodynamic properties of a thermoacoustic swirl combustor

Many practical lean-premixed combustion systems involved in land-based power plants, gas turbines and boilers are susceptible to self-excited combustion instability, which is characterized by detrimental periodic pressure oscillations. Little attention has been paid on experimentally characterizing the chemical emissions and thermodynamic properties of a thermoacoustic swirl combustor. In this work, the effects of (1) fuel-air equivalence ratio Φ and fuel flow rate QCH4 on generating such combustion instability and its impact on chemical emissions and thermodynamic properties in a swirling combustor are experimentally studied. For this, a methane-fueled lab-scale swirl combustor is designed and tested. To monitor the thermodynamic properties of the combustor, an acoustic pressure sensor, an infrared thermal imaging camera, K-type thermal couples, and an infrared flue gas analyzer are applied. It is found that the fuel-air ratio plays an important role on generating combustion instability at different frequencies and amplitudes. This is confirmed by conducting autocorrelation and frequency spectrum analyses of the acoustic pressure time trace. Furthermore, the dominant mode swap (mode-switching) between a low frequency ω1 and a high non-harmonic one is experimentally observed. Whether the mode switching from high (harmonic or non-harmonic) to low frequency or low to high frequency is found to depend strongly on QCH4. As the equivalence ratio is changed from lean to rich, i.e. 0.8 ≤ Φ ≤ 1.2, NOx emission is increased from 1 ppm to 37 ppm. However, CO emission is decreased by 2 order of magnitudes from 1000 ppm first and then increased. The minimum CO emission is approximately 3.0 ppm. In addition, O2 concentration is decreased by more than 80% with increased Φ, depending on the methane flow rate. This means that the combustion efficiency characterized by the O2 emission is decreased dramatically from 99.5% to 68% with Φ increased from 0.6 to 1.2. The present work sheds light on the characteristics of chemical emissions and thermodynamic properties, when a thermoacoustic swirl combustor is operated with methane-air equivalence ratio Φ varied from lean to rich condition and different QCH4. It opens up a practical means to design a stably operated but low-emission thermoacoustic swirl combustor.

Separation of hydrogen sulfide from gas phase using Ce3+/Mn2+-enhanced fenton-like oxidation system

A novel separation process of hydrogen sulfide from gas phase using Ce3+/Mn2+-enhanced Fe3+/H2O2 oxidation systems (i.e., Ce3+/Mn2+-enhanced Fenton-like oxidation systems) in a bubbling stirred reactor was developed. Experiments were conducted to study the effects of several influencing factors (Fe3+ and H2O2 concentrations, concentrations of Ce3+/Mn2+, solution temperature, H2S inlet concentration, gas flow rate, stirring rate and initial solution pH) on H2S removal. Ion chromatography, high performance liquid chromatography, flue gas analyzer and electron spin resonance capture technology were used to measure the reaction products and free radicals in H2S removal process. Mechanism and routes of H2S removal were also proposed preliminarily. The results reveal that addition of Ce3+/Mn2+ effectively enhances H2S removal in Fenton-like oxidation system. The enhancement effects are caused by production of more OH that are produced from synergistic effect between Fe3+ and Ce3+/Mn2+ in the Fenton-like oxidation systems. H2S removal efficiency was increased by increasing Fe3+ concentration and concentrations of Ce3+/Mn2+, and decreased by increasing H2S inlet concentration and gas flow rate. Increasing H2O2 concentration, solution temperature, stirring rate and initial solution pH show double impact on H2S removal. H2S is mainly removed by oxidation of OH (it is the main reaction route of H2S removal). The new removal technology can provide new an option for removal of gaseous hydrogen sulfide.

Study on the characteristics of evaporation–atomization–combustion of biodiesel

A great deal of research is being carried out on renewable diesel fuels. The number of raw materials (especially waste, animal, and vegetable oils), production technologies, and additives of biodiesel is increasing. In our work, a evaporation–atomization–combustion system consisting of a biomass liquid fuel was designed to produce a laminar premixed flame for studying the combustion–emission characteristics of biodiesel. The combustion characteristics of biodiesel including flame height, flame front area, flame speed, and OH total signal intensity were studied by planar laser-induced fluorescence of OH (OH-PLIF). The emission characteristics of biodiesel (CO, CO2, and NO) were studied with a flue gas analyzer. The experimental results showed that the flame height, flame front area, flame speed, and the OH total signal intensity changed with the equivalence ratio (Φ). The relationship between the OH radical intensity and the emission of CO/CO2 was obtained from the OH-PLIF average signal intensity. The [CO]/[CO2] ratio decreased with the OH-PLIF average signal intensity. Finally, we obtained the relationship between the OH-PLIF average signal intensity and the NO emissions.

Application of biomass fraction at industrial waste incinerator

The factor required for estimating greenhouse gas emission, i.e. the fossil carbon fraction, excludes the biomass fraction of incinerated waste and can be applied as a major factor in estimating greenhouse gas emissions. In Korea, the amount of greenhouse gases emitted from waste incineration facilities is calculated by using a solid waste incinerated amount default values (biomass fraction, content of dry matter, etc.) provided by the Intergovernmental Panel on Climate Chang (IPCC). However, this method cannot reflect the characteristics of Korea. This method is likely to overestimate or underestimate the amount of greenhouse gas emissions. This study aims to investigate the difference in emissions between the actual values of the biomass content based on the exhaust gas standard and the IPCC defaults applied in the calculation of the national emissions. The comparative result indicates that the amount of greenhouse gas emissions calculated using the solid waste composition method is 70.71 tons CO2/day and using the flue gas analysis is 56.92 tons CO2/day. This verifies that the former method overestimates the amount of greenhouse gas emissions compared with the latter method. The difference is caused by applying both factors in estimating greenhouse gas emissions and the basic values provided in the IPCC guideline. In addition, although the IPCC reported 10% of biomass content, it is 41.06% as a result of actual analysis, and hence, it is considered that there will be a difference depending on the biomass content. Thus, to increase the reliability of the calculated greenhouse gas emissions, these should be estimated by considering national characteristics.

Small-scale biogas plants in central Vietnam and biogas appliances with a focus on a flue gas analysis of biogas cook stoves

Abstract The major objective of this paper is to fill the research gap regarding small-scale biogas appliances by performing a flue gas analysis of biogas cook stoves in Vietnam. The methods of data collection included a questionnaire survey of rural households (n = 93), discussions with local consultants (n = 6) and observations in central Vietnam. Furthermore, flue gas analyses of biogas cook stoves were performed (n = 93). As the most common appliances, biogas cook stoves were reported as a substitute for conventional cook stoves, eliminating indoor smoke pollution and related health risks. The majority (96%) of biogas cook stoves were two-flame burners that averaged 2.4 (±0.74) years of age and were in use for over 3 h per day. High concentrations of CO in its diluted (8705.35 ± 1790.01 mg m−3) and undiluted forms (24,758.2 ± 4860.2 mg m−3) were detected in biogas flue gas. The concentration of unavoidable produced NO averaged 0.064 (±0.12) mg·m−3, which is an acceptable value for the transformation of biodegradable wastes into biogas that is consequently burned. The study contributes to covering the data gap, as similar studies have not been conducted in Vietnam. The information and data gained are important for further evaluations of biogas technology in Vietnam and other developing countries.

Comparative analysis of desulphurization methods of tyre pyrolysis oil (TPO)

Tyre pyrolysis oil (TPO) has a potential to be used as furnace oil. It is more economical option than diesel or other commercial fuel but its high level of impurities and resultant air pollution hinders its application. Present study focuses on the oxidative desulphurization of TPO with three different treatments, i.e. formic acid/H2O2, acetic acid H2O2 and nitric acid having different concentrations (10, 20 and 30%) at different temperature (40, 50, and 60 °C). Crude and desulphurized TPO were burned in a closed container and the variation in their gaseous emissions (O2, CO, SOx, NOx and CO2) was observed using flue gas analyser. All treatments were found effective for reduction of gaseous emissions, but 20% acetic acid at 50 °C was found as the best treatment along with 10% formic acid at 40 °C and 30% nitric acid treatment. Overall, 97.29% of SOx, 99.6% of NOx and 99.9% of CO2 removal was observed from the crude TPO after its oxidative desulphurization. Desulphurization also affected the viscosity and calorific value of TPO. Viscosity of oil decreased from 0.83 to 0.202 cST at 20% formic acid 40 °C treatment, and the calorific value varied from 43.98 to 43.6 M/kg 10% nitric acid. Reduction in sulphur dioxide in exhaust of treated samples as compared to crude indicates high removal of sulphur from crude oil after treatments. Overall, acidic oxidative desulphurization proved to be effective for purification of oil by reduction in gaseous emissions and viscosity.

Effects of synthetic gas constituents on combustion and emission behavior of premixed H2/CO/CO2/CNG mixture flames

In this study, effects of synthetic gas constituents on combustion and emission behavior of premixed H2/CO/CO2/CNG blending synthetic gas flames were experimentally investigated in a swirl stabilized laboratory scale combustor. Effects of these constituents on flashback and blowout equivalence ratios of respective mixtures were also determined. Firstly, mixtures of CNG/H2/CO with varying H2/CO ratios were tested and then each mixture was diluted with the same amount of CO2 (20% by volume) to better represent synthetic gas. H2/CO ratios of tested gas mixtures were so adjusted that heating value of each gas mixture was low, moderate or high. Combustion behavior of such mixtures was evaluated with respect to measured axial and radial temperature values. Moreover, emission behavior was analyzed by means of emitted CO, CO2 and NOx levels. Flame temperature measurements were conducted with B and K type thermocouples. Emission measurements were performed with a flue gas analyzer, which was equipped with a ceramic coated probe, as well. Results of this study revealed the great impact of gas composition on combustion and emission behavior of studied flames. Two main findings are: H2/CO ratio slightly alters temperature distribution throughout combustor, while hydrogen reaction kinetics play the most significant role in synthetic gas combustion (1), CO2 addition tremendously increases emissions of CO (2).

Experimental study on reaction characteristics of NO in (NH4)2SO3 solution

The effects of various factors on the NO removal activity in the (NH4)2SO3 solution were investigated to explore more details and characteristics of the related reactions using full infrared sensor flue gas analyzer (FISFGA). It was found that the conversion yield of NO (9.0%–29.0%) was obviously improved with the increase of gas–liquid contact area, NO residence time and (NH4)2SO3 concentration as well as the adding of CuSO4. However, it was mainly limited by gas–liquid mass transfer rate and slightly inhibited by the gas velocity. Moreover, the FISFGA analysis revealed that two nitric oxide (NO) conversion route with different reduction product of N2O and N2 existed simultaneously upon the existence form of SO32−. It was confirmed by the calculations and the experiments of pH factor that the NO reduction steps were based on the following equation: (1) NO+HSO3−⇋N2O+SO42−+H+; (2) NO+SO32−⇋N2+SO42−. In this system, Eq. (1) with N2O product was the major pathway, but the ratio of Eqs. (2) to (1) was intensified in the presence of CuSO4. It is believed that the suitable additives could promote the NO reduction to N2 furtherly.

Effect of oxy-fuel combustion on flame characteristics of low calorific value coal gases in a small burner and combustor

Currently, using oxygen instead of air in a combustion process is being widely discussed as an option to reduce fuel consumption and utilization of oxygen is expected to improve the thermal efficiency and combustion performances. The main goal of this study is to determine the combustion behaviors of low calorific value coal gases under oxy-fuel combustion conditions and to compare with the results of air-fuel combustion conditions in the existing burner and the combustor. The coal-derived low calorific value coal gases (syngases) have been properly oxy-combusted using the existing burner within the present study. Temperature and emission values have been experimentally measured and investigated on different axial and radial positions by using thermocouples and a flue gas analyzer throughout the combustion chamber. All experiments have been performed under a thermal power of 10 kW and an excess oxygen coefficient of λ = 1.2 combustion conditions for both turbulator distances of 7 cm and 2 cm. The burner walls were overheated due to using of pure oxygen instead of air during combustion when the turbulator position of the burner was further to the burner exit (7 cm). Because of that, the turbulator position of the burner has also been changed as a small modification to alleviate overheating of the burner walls and hence, it was drawn near to the burner exit (2 cm). Therefore, it can be said that the burner either can be used with modification or the burner material should be changed to be withstood higher temperature levels. It is consequently concluded that the flame that has emerged under combustion condition with 2 cm of the turbulator distance is wider and smoother than that of the flame showing up under combustion condition with 7 cm of the turbulator distance. CO, CO2 and NOX emissions have also been determined on different axial and radial positions. According to the measurements, it has been demonstrated that CO2 and NOX decrease while CO increase on the axial measurements as the turbulator distance is draw near to the burner exit. When the oxy-fuel combustion results are compared with the air-fuel combustion results, it can be concluded that the oxy-fuel combustion performances of the coal-derived syngases are better than that of the air-fuel combustion, which corresponds to an increment of about 22% in their flame temperatures. However, it has been obtained that oxy-fuel NOX values are not lower than that of the air-fuel values due to the higher flame temperatures. It has been revealed that oxy-fuel CO emission values are lower and oxy-fuel CO2 emission values are higher (approximately 30%) than values of the air-fuel combustion due to the absence of nitrogen in the oxidizer.

Application of banana peels waste as adsorbents for the removal of CO2, NO, NOx, and SO2 gases from motorcycle emissions

The aims of the study were to investigate the application of banana peels as adsorbent for the removal of CO, NO, NOx and SO2 gases from motorcycles emissions. The effect of differents thermal activation on the characteristics of banana peels adsorbent (BPA) such as moisture content, ash content, volatile matter and fixed carbon has been studied using proximate analysis. The study of Iodine adsorption capacity of BPA was obtained at 952 mg/g adsorbent. Structure and morphology of BPA were characterized by Fourier transform infrared (FTIR) and field emission scanning electron microscopy (SEM). The results showed that BPA could significantly adsorbed the CO and SO2 gases emissions from motorcycles, but not applicable for NO, NOx gases. After 10 minutes of flue gas analysis at idle mode using BPA adsorption tube, CO gas could be totally removed, from initial 19618 ppm to 0 ppm, while SO2 gas could also be totally removed from 24523 ppm to 0 ppm. SEM test showed that temperature of activation had significant effect on the size of pores of BPA formed. BPA was suitable for application in removing CO and SO2 gases emissions from motorcycles and it helps to reduce the green house gas effects of fossil fuel to the environment.

An experimental study on effect of coke ratio on SO2 and NOx emissions in sintering process

By using the sinter cup experiment, the effects of different coke ratios of 0%, 25%, 50%, 75%, and 100% on the formation and total emissions of SO2 and NOx in the sintering process were studied with the Testo350 flue gas analyzer. The experimental results show that the emissions of SO2 and NOx are closely related to sintering process. With the increase of the coke proportion, the sintering temperature changes and the maximum peak time appears earlier. SO2 concentration has a bimodal distribution and NOx concentration has a triple peak. Besides, the both maximum peaks appear at the end of sintering. In addition, due to the increasing of the S and N contents in the fuel with the coke ratios from 0% to 100%, the amounts of SO2 and NOx emissions are raised respectively at 10.82 mg, 11.42 mg, 13.84 mg, 13.69 mg, 20.36 mg and 3.11 mg, 3.39 mg, 4.44 mg, 4.31 mg, 6.16 mg.

Exergy analysis of flue gases and modeling with ANN

Exergy analysis of flue gases and modeling with ANN