scholarly journals Effect of Mineral Additives on Fusion Behavior of Agricultural Residue Ashes during Combustion or Co-combustion with Lignite

2021 ◽  
Vol 03 (04) ◽  
pp. 1-1
Author(s):  
Despina Vamvuka ◽  
◽  
Maria Deli ◽  
Antonios Stratakis ◽  
◽  
...  
Keyword(s):  
Positive Impact ◽  
Initial Deformation ◽  
Fluid Temperature ◽  
High Concentration ◽  
Agricultural Residue ◽  
Ash Melting ◽  
Ash Fusibility ◽  
Biomass Materials ◽  
Combustion Processes ◽  
Mineral Additives

In this work, the ash fusibility behaviour of selected agricultural residues and their blends with lignite was studied, by carrying out chemical, mineralogical, fusibility and thermogravimetric analyses and calculating slagging/fouling indicators for predicting deposition tendencies in boilers. Two additives, bauxite, and clinochlore, were used at varying amounts to reduce ash melting, followed by examining their anti-fusion mechanisms. Initial deformation and softening temperatures of biomass materials were low for combustion processes operating above 900 °C due to their high concentration in K, Na, and P compounds. When the additives were mixed with raw fuels or lignite/biomass blends, the initial deformation of ashes started at temperatures up to 340 °C higher, whereas the fluid temperature in most cases exceeded 1500 °C. Bauxite was more effective than clinochlore. The positive impact of additives was attributed to the mineralogical transformations during ashing to phases with a high melting point through reactions with K, Na-bearing minerals, or CaO of fuel ashes.

scholarly journals ASH FUSIBILITY CHARACTERISTICS OF SOME BIOMASS FEEDSTOCKS AND EXAMINATION OF THE EFFECTS OF INORGANIC ADDITIVES

2010 ◽  
Vol 41 (2) ◽  
pp. 13 ◽  
Author(s):  
Giuseppe Toscano ◽  
Fabrizio Corinaldesi
Keyword(s):  
Melting Temperature ◽  
Thermal Behaviour ◽  
Technical Problems ◽  
Ash Melting ◽  
Ash Fusibility ◽  
Biomass Materials ◽  
Solid Biomass ◽  
Mineral Additives ◽  
Corn Grain ◽  
Qualitative And Quantitative Characteristics

<p>The increased consumption of solid biomass for energy production has raised a number of technical problems that are mainly related to the variability of the chemical-physical characteristics of feedstocks. The low melting temperature of their inorganic fraction is the main cause of these problems. In this work analysis and comparison of the thermal behaviour of ash from 20 different feedstocks highlighted that biomass materials with the same origin share similar qualitative and quantitative characteristics. A feedstock from a starch group, corn grain, was tested for the effects of four mineral additives (MgO, CaO, Ca- CO3, and SiO2) on ash deformation temperature. MgO and CaO seemed to be the most effective, raising ash melting temperature and enhancing the thermal behaviour of the feedstock. The results of supplementation of the initial corn grain, wheat straw and sunflower cake biomass demonstrated that the amount of additive to be used is a function of biomass type and can depend on its ash content.</p>

scholarly journals Experimental and Theoretical Analysis of a Linear Focus CPV/T System for Cogeneration Purposes

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2960 ◽  
Author(s):  
Carlo Renno
Keyword(s):  
Focal Length ◽  
Concentration Field ◽  
Operating Conditions ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Atmospheric Conditions ◽  
High Concentration ◽  
Environment Temperature ◽  
Temperature Levels ◽  
T System

The knowledge of the actual energy performances of a concentrating photovoltaic and thermal (CPV/T) system with a linear focus optics, allows to evaluate the possibility of adopting this type of system for cogeneration purposes. Hence, the main aim of this paper is the design, realization, setting and modeling of a linear focus CPV/T system in the high concentration field. An experimental linear focus CPV/T plant was created in order to determine its electrical and thermal performance under different working conditions in terms of environment temperature, sunny and cloudy conditions, focal length, etc. Moreover, a theoretical model of the linear focus CPV/T system was also studied. This model evaluates the temperatures of the working fluid that flows in the cooling circuit of the CPV/T system under several operating conditions. The temperatures of the triple junction (TJ) cells, experimentally evaluated referring to different solar radiation and atmospheric conditions, were considered as the input data for the model. The values of the fluid temperature, theoretically and experimentally determined, were thus compared with good agreement. The electrical production of the CPV/T system depends generally on the TJ cell characteristics and the concentration factor, while the thermal production is above all linked to the system configuration and the direct normal irradiance (DNI) values. Hence, in this paper the electric power obtained by the linear-focus CPV/T system was evaluated referring to the cogeneration applications, and it was verified if the TJ cell and the cooling fluid reach adequate temperature levels in this type of system, in order to match the electrical and the thermal loads of a user.

Ohmic and viscous dissipation effects on micropolar non-Newtonian nanofluid Al2O3 flow through a non-Darcy porous media

2022 ◽  
pp. 1-13
Author(s):  
Nabil T. Eldabe ◽  
Mohamed Y. Abou zeid ◽  
Sami M. El Shabouri ◽  
Tarek N. Salama ◽  
Aya M. Ismael
Keyword(s):  
Magnetic Field ◽  
Heat Source ◽  
Numerical Solutions ◽  
Tangential Velocity ◽  
Darcy Number ◽  
Physical Parameters ◽  
Fluid Temperature ◽  
High Concentration ◽  
Ohmic Dissipation ◽  
Similarity Transformations

Inclined uniform magnetic field and mixed convention effects on micropolar non-Newtonian nanofluid Al2O3 flow with heat transfer are studied. The heat source, both viscous and ohmic dissipation and temperature micropolarity properties are considered. We transformed our system of non-linear partial differential equations into ordinary equations by using suitable similarity transformations. These equations are solved by making use of Rung–Kutta–Merson method in a shooting and matching technique. The numerical solutions of the tangential velocity, microtation velocity, temperature and nanoparticle concentration are obtained as functions of the physical parameters of the problem. Moreover, we discussed the effects of these parameters on the numerical solutions and depicted graphically. It is obvious that these parameters control the fluid flow. It is noticed that the tangential velocity magnifies with an increase in the value of Darcy number. Meanwhile, the value of the tangential velocity reduces with the elevation in the value of the magnetic field parameter. On the other hand, the elevation in the value of Brownian motion parameter leads to a reduction in the value of fluid temperature. Furthermore, increasing in the value of heat source parameter makes an enhancement in the value of nanoparticles concentration. The current study has many accomplishments in several scientific areas like medical industry, medicine, and others. Therefore, it represents the depiction of gas or liquid motion over a surface. When particles are moving from areas of high concentration to areas of low concentration.

scholarly journals Effect of Harvest Season on the Fuel Properties of Sida hermaphrodita (L.) Rusby Biomass as Solid Biofuel

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3398 ◽  
Author(s):  
Nikola Bilandžija ◽  
Tajana Krička ◽  
Ana Matin ◽  
Josip Leto ◽  
Mateja Grubor
Keyword(s):  
Positive Impact ◽  
Raw Materials ◽  
Cell Structure ◽  
Combustion Process ◽  
Electric Energy ◽  
Energy Crops ◽  
Fuel Properties ◽  
Biomass Combustion ◽  
Solid Biofuel ◽  
Combustion Processes

Biomass obtained from cultivated energy crops is one of the raw materials with the highest potential in renewable energy production. Although such biomass can be used in production of lignocellulose bioethanol, it is currently mostly used as solid fuel for generating heat and/or electric energy via combustion processes. Calorific values, proximate and ultimate analysis, cell structure and micro- and macro-elements data are considered as basic parameters in the valorization of fuel properties during biomass combustion processes. Energy crops are cultivated with the aim to produce the largest possible quantity of biomass with minimal agro-technical inputs. One of these crops is Sida hermaphrodita (L.) Rusby. Given the fact that the chemical composition of biomass is influenced by a number of agro-ecological and agro-technical factors, the aim of this work was to determine the fuel properties of Sida hermaphrodita biomass obtained from three different harvest seasons (autumn, winter and spring) and cultivated in the area of the Republic of Croatia. On the basis of these investigations it was possible to conclude that harvest delaying towards spring season had a positive impact on suitability of using biomass of Sida hermaphrodita in the combustion process, which primarily means significant lowering the contents of moisture (18.64%), ash (1.94%), and nitrogen (0.65%), but also means increasing the contents of fixed carbon (6.21%) and lignin (25.45%).

Ash Fusibility Based on Modes of Occurrence and High-Temperature Behaviors of Mineral Matter in Coals

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Xinye Cheng ◽  
Kexin Han ◽  
Zhenyu Huang ◽  
Zhihua Wang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Melting Process ◽  
Mineral Matter ◽  
Slight Reduction ◽  
Modes Of Occurrence ◽  
Ash Melting ◽  
Ash Fusibility ◽  
Three Stages ◽  
The Common

Complete quantitative data of the chemical (proximate, ultimate, and ash analyses) and mineral (in low-temperature ash (LTA) and various high-temperature ashes (HTA)) compositions of 21 coals were used to investigate the modes of occurrences and high-temperature behaviors of the minerals in coals and their influence on ash fusibility. The common minerals present in the low-temperature ashes (LTA) are kaolinite, quartz, muscovite, calcite, gypsum, pyrite, and siderite. The samples were divided into two groups according to the hemispherical temperature for a comparative study of the behavior of mineral matters. Results show that the average number of mineral species (ANMS) and amorphous substances (AS) in the LTAs of the two groups are essentially the same. The ANMS in both the low and high (ash fusion temperatures, AFT) ash samples go through the same tendency of a slight reduction at first, an increase, and finally, a significant reduction. As the temperature increases, the ANMS in the low-AFT ash is initially higher and then lower than the high-AFT ash, whereas the tendency of the AS is quite the opposite. The ash melting process is divided into three stages, and the AFTs are related to different degrees of the eutectic stage.

Effects of Firing Conditions on the Coal Ash Fusibility Test

2010 ◽  
Vol 72 ◽  
pp. 87-92
Author(s):  
Dario Montinaro ◽  
Massimo Malavasi ◽  
Gloria Amante ◽  
Antonio Chiechi ◽  
Antonio Licciulli
Keyword(s):  
Digital Camera ◽  
Coal Ash ◽  
Heating Process ◽  
Melting Behaviour ◽  
Shape Transformation ◽  
Dry Air ◽  
Gas Atmosphere ◽  
Ash Melting ◽  
Dry Conditions ◽  
Ash Fusibility

In the present work, the melting behaviour of ashes obtained from the combustion of coals from different seams were investigated by a laboratory-scale equipment. The ash melting behaviour was studied by heating the specimens in a tubular furnace under a controlled gas atmosphere, while continuous monitoring the shape transformation by a digital camera. The ash fusibility temperatures (AFT) were determined by using an application which allows the in-line identification of the AFT-related shapes specified in the ASTM D 1857-04. The effect of the furnace gas-atmosphere on the determination of the ash fusion temperatures were studied by performing the measurements under dry-air, SO2-rich-air and humidified air environments. It was found that under dry conditions, AFT determination is significantly affected by slag foaming, leading to an overestimation of the melting temperatures. Low water vapour concentrations does not appreciably change the results obtained under dry air, while SO2-rich atmosphere seems to reduce foaming. As a result, since no volume expansion was observed, samples heated under SO2-air flow, apparently melt at lower temperatures with respect to dry air conditions. The mineral phases transformation of the ashes during the heating process was studied by X-Ray diffraction and it was found that the low temperature transformations are essentially related to Iron and Alkalis reaction with aluminosilicates to form a glassy phase. On the other hand, high temperatures transformations are related to quartz and mullite solubilization which is closely dependent to the amount of Calcium, and therefore of anorthite phase, in the ash sample.

scholarly journals Ash Melting Behavior of Rice Straw and Calcium Additives

Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1282
Author(s):  
Veronika Chaloupková ◽  
Tatiana Ivanova ◽  
Petr Hutla ◽  
Monika Špunarová
Keyword(s):  
Rice Straw ◽  
Positive Impact ◽  
Melting Behavior ◽  
Biofuel Production ◽  
Biomass Ash ◽  
Melting Temperatures ◽  
Ash Melting ◽  
Ash Melting Behavior ◽  
Large Formation ◽  
Feedstock Material

Rice straw is potentially an appropriate feedstock material for biofuel production, since a huge amount of this postharvest residue is generated every year. The transformation of such agricultural biomass into densified products with a higher energy value and their subsequent combustion is associated with several questions. One of them is that rice straw exhibits a large formation of ash during combustion; thus, it is essential to know the nature of its ash melting behavior. Generally, during the combustion of straw biomass, ash sintering occurs in relatively low temperatures, resulting in the damaging of heating equipment. This negative aspect can be overcome by the addition of calcium-based additives. This paper aimed to study the ash melting behavior at a laboratory scale and to determine the ash melting points of rice straw mixed with calcium carbonate (CaCO3) and calcium hydroxide (Ca(OH)2) in different proportional ratios. The standardly produced ash samples from the rice straw obtained from Cambodia were constantly heated up in a muffle furnace, and characteristic temperatures of ash melting, i.e., shrinkage, deformation, hemisphere, and flow temperature, were recorded. The results showed that increasing the additive ratio did not bring linear growth of the melting temperatures. The addition of 1% CaCO3 showed an optimal positive impact of higher ash melting temperatures, and thus a better ability to abate the sintering of the rice straw ash.

scholarly journals Synthesis of Atmospherically Stable Zero-Valent Iron Nanoparticles (nZVI) for the Efficient Catalytic Treatment of High-Strength Domestic Wastewater

Catalysts ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Afzal Ansari ◽  
Vasi Uddin Siddiqui ◽  
Md. Khursheed Akram ◽  
Weqar Ahmad Siddiqi ◽  
Anish Khan ◽  
...  
Keyword(s):  
Positive Impact ◽  
Oxygen Demand ◽  
Visible Spectrum ◽  
Aerobic Condition ◽  
Domestic Wastewater ◽  
Operating Conditions ◽  
Bandgap Energy ◽  
Ambient Conditions ◽  
High Concentration ◽  
Catalytic Treatment

Here, we report the fabrication of nZVI by the wet chemical technique in the presence of ethanol using ferric iron and sodium borohydride as the reducing agents under ambient conditions. The obtained nZVI particles are mainly in a zero-valent oxidation state and do not undergo significant oxidation for several weeks. The structural and morphological parameters of nZVI were investigated by using UV, XRD, SEM, EDX, TEM, and DLS analysis. The optical nature, bandgap energy, and absorption edge were all revealed by the UV–visible spectrum. The phase development and crystallinity of nZVI particles were shown by the XRD pattern. The morphological investigation revealed that the nanoparticles were spherical with an average size of 34–110 nm by using ImageJ software, and the elemental analysis was analyzed using EDX. Furthermore, the catalytic treatment performance of domestic wastewater was evaluated in terms of pH, COD (chemical oxygen demand) solubilization, total solids (TS), volatile solids (VS), phosphorous, and total nitrogen (TN) reduction under aerobic and anaerobic operating conditions. The effluent was subjected to a process evaluation with a different range (100–500 mg/L) of nZVI dosages. The COD solubilization and suspended solids reduction were significantly improved in the anaerobic condition in comparison to the aerobic condition. Furthermore, the effect of nZVI on phosphorous (PO43−) reduction was enhanced by the electrons of iron ions. The high concentration of nZVI dosing has a positive impact on COD solubilization and phosphorous removal regardless of the aeration condition with 400 mg/L of nZVI dosage.

scholarly journals Factors Influencing Competitiveness in the Global Beer Trade

2020 ◽  
Vol 12 (15) ◽  
pp. 5957
Author(s):  
Áron Török ◽  
Ákos Szerletics ◽  
Lili Jantyik
Keyword(s):  
Positive Impact ◽  
Descriptive Analysis ◽  
Quality Level ◽  
Foreign Direct Investments ◽  
Panel Regression ◽  
High Concentration ◽  
Factors Influencing ◽  
Comparative Advantages ◽  
Negative Effect ◽  
Beer Production

Beer is a widely produced, consumed, and traded alcoholic drink all around the world. This paper investigates the factors influencing competitiveness in the global beer trade on the macroeconomic level. To reach this aim, descriptive analysis and panel regression together with stability tests were used on the global beer market from 1998 to 2017. Results showed high concentration both in global production and trade, while except for the most competitive beer-exporting countries, the level of comparative advantages has significantly changed in these three decades. Based on the panel regression models, total beer production and per capita consumption, EU membership, and the number of beers with geographical indications have a positive impact on comparative advantages. In contrast, barley production, level of foreign direct investments, size of the population, GDP/capita, and high quality level of the beer export have a negative effect.

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