scholarly journals Investigation of the Characteristics of Catalysis Synergy during Co-Combustion for Coal Gasification Fine Slag with Bituminous Coal and Bamboo Residue

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1152
Author(s):  
Yixin Zhang ◽  
Wenke Jia ◽  
Rumeng Wang ◽  
Yang Guo ◽  
Fanhui Guo ◽  
...  

As a kind of solid waste from coal chemical production, the disposal of coal gasification fine slag poses a certain threat to the environment and the human body. It is essential for gasification slag (GS) to realize rational utilization. GS contains fewer combustible materials, and the high heating value is only 9.31 MJ/Kg, which is difficult to burn in combustion devices solely. The co-combustion behavior of the tri-fuel blends, including bituminous coal (BC), gasification slag (GS), and bamboo residue (BR), was observed by a thermogravimetric analyzer. The TGA results showed that the combustibility increased owing to the addition of BC and BR, and the ignition and burnout temperatures were lower than those of GS alone. The combustion characteristics of the blended samples became worse with the increase in the proportion of GS. The co-combustion process was divided into two main steps with obvious interactions (synergistic and antagonistic). The synergistic effect was mainly attributed to the catalysis of the ash-forming metals reserved with the three raw fuels and the diffusion of oxygen in the rich pore channels of GS. The combustion reaction of blending samples was dominated by O1 and D3 models. The activation energy of the blending combustion decreased compared to the individual combustion of GS. The analysis of the results in this paper can provide some theoretical guidance for the resource utilization of fine slag.

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1804 ◽  
Author(s):  
Nawar Al-Esawi ◽  
Mansour Al Qubeissi ◽  
Ruslana Kolodnytska

The interest in biofuels was stimulated by the fossil fuel depletion and global warming. This work focuses on the impact of biodiesel fuel on ethanol/diesel (ED) fuel blends. The soybean methyl ester was used as a representative composition of typical biodiesel fuels. The heating and evaporation of ethanol–biodiesel–diesel (EBD) blends were investigated using the Discrete–Component (DC) model. The Cetane Number (CN) of the EBD blends was predicted based on the individual hydrocarbon contributions in the mixture. The mixture viscosity was predicted using the Universal Quasi-Chemical Functional group Activity Coefficients and Viscosity (UNIFAC–VISCO) method, and the lower heating value of the mixture was predicted based on the volume fractions and density of species and blends. Results revealed that a mixture of up to 15% biodiesel, 5% ethanol, and 80% diesel fuels had led to small variations in droplet lifetime, CN, viscosity, and heating value of pure diesel, with less than 1.2%, 0.2%, 2%, and 2.2% reduction in those values, respectively.


Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2484
Author(s):  
Tomasz Turzyński ◽  
Jacek Kluska ◽  
Mateusz Ochnio ◽  
Dariusz Kardaś

This paper describes characteristics of the combustion of sunflower husk (SH), sunflower husk pellets (SHP), and, for comparison, hardwood pellets (HP). The experiments were carried out using a laboratory-scale combustion reactor. A proximate analysis showed that the material may constitute an alternative fuel, with a relatively high heating value (HHV) of 18 MJ/kg. For SHP, both the maximum combustion temperatures (TMAX = 1110 °C) and the kinetic parameters (temperature front velocity vt = 7.9 mm/min, combustion front velocity vc = 8 mm/min, mass loss rate vm = 14.7 g/min) of the process were very similar to those obtained for good-quality hardwood pellets (TMAX = 1090 °C, vt = 5.4 mm/min, vc = 5.2 mm/min, vm = 13.2 g/min) and generally very different form SH (TMAX = 840 °C, vt = 20.7 mm/min, vc = 19 mm/min, vm = 13.1 g/min). The analysis of ash from SH and SHP combustion showed that it has good physicochemical properties (ash melting point temperatures >1500 °C) and is safe for the environment. Furthermore, the research showed that the pelletization of SH transformed a difficult fuel into a high-quality substitute for hardwood pellets, giving a similar fuel consumption density (Fout = 0.083 kg/s·m2 for SHP and 0.077 kg/s·m2 for HP) and power output density (Pρ = MW/m2 for SHP and 1.5 MW/m2 for HP).


2020 ◽  
Vol 1 (1) ◽  
pp. 8-16
Author(s):  
Muhammad Suyoko ◽  
Kemas Ridhuan ◽  
Untung Surya Dharma

Biomass is a solid waste derived from biological material that can be generated as fuel. Biomass includes plantation, agriculture, household, forest waste and waste from the wood industry, one of the uses of biomass is bio-pellet. Bio-pellet is an alternative type of energy in the form of solid fuel made from biomass raw material with a size smaller than the size of briquettes. In this research, raw materials from teak wood, acacia, and sengon wood powder were used as well as a mixture of coconut shell charcoal with tapioca adhesive. This study aims to determine the bio-pellet estimation analysis, determine the heating value required by the bio pellet in the combustion process, and determine the burning characteristics of the three types of bio pellets. The method used in this study was the process of making bio-pellet with the same treatment on each bio-pellet, variations bio pellet will be made is 50% teak wood powder and 50% coconut shell charcoal powder, 50% acacia wood powder and 50% coconut shell charcoal powder, and 50% sengon wood powder and 50% coconut shell charcoal powder. Each bio pellet uses an adhesive mixture of 5% of the raw material. The stages of the testing process are bio pellet in laboratory tests to determine the value of the composition of the levels of heat, water, ash, flying substances, and bound carbon. The next testing process is the testing process of bio pellet combustion using a bio pellet stove with a process of boiling 10 liters of water, with fire temperature, water temperature, and the remaining fuel measured. All was done at UM Metro 2 campus. The results of bio pellet testing in the laboratory stated that the highest value was in sengon bio pellet with heating value of 5815.19 cal/g, water content of 5.82%, the ash content of 9.77%, levels of flying matter 69.37%, and carbon content bound 19, 41%. For the high heating value of bio pellet burning is 784.92 kcal/hour. Then the best efficiency is the sengon bio- pellet with a value of 55%.


2013 ◽  
Vol 772 ◽  
pp. 487-494 ◽  
Author(s):  
Yu Zhong Li ◽  
Xiao Qian Ma ◽  
Yu Ting Tang ◽  
Zi Lin Cai

The combustion of paper mill sludge and bituminous coal in air was analyzed using a thermogravimetric instrument. TG and DTG curves for the blends lies between that of the individual fuels, and the main combustion characteristics of blends depended on individual fuels and followed the weighted average. As the blending ratio of paper mill sludge was increased from 10% to 90%, the ignite temperature (Ti) decreased from 529.6°C. to 275.6°C., and residual weight increased from 19.28% to 47.39%. The TG profiles of sample were almost the same at different heating rates, however there was a big difference between the DTG profiles. The maximum weight loss rate of sample increased obviously with the increment of heating rate. This work contributes to the comprehensive understanding of paper mill sludge and bituminous coal combustion and development of co-combustion technology.


2020 ◽  
Vol 3 (3) ◽  
pp. 121-138
Author(s):  
Dr. Bilal Ahmad Khan

Islamic economics based on specific concept of universe and the creation of man is contradictory to the concept adopted and accepted by modern science. Islamic economics postulates although ability and expertise is required for progress and growth but distribution of resources completely dependent on it would be cruel, inhuman and bereft of kindness, and lead to oppression. Islamic economics does not favor making human ability and expertise the fulcrum of resource distribution. It should be kind, considerate and based on justice and fairness. This is because according to Islamic philosophy, ownership is considered to be a trust from Allah which has been bestowed on the rich so that they may utilize it correctly. In Islamic economics the role of the individual, has inclinations and his aims and objectives occupy a central position and are vitally important. He is definitely a rational being but his level of rationality is not confined to the calculations of cost and profit. An individual does not want merely to obtain monetary profit and physical pleasure and leisure but he also wants and aims for something beyond what the material world has to offer. The main aim of the study is to find out the relationship between Islam and economics. In Islamic economics the comprehensive moral training of the individual, his technical and educational ability, his aims and his priorities are of primary importance. According to Islamic economics the means of acquiring wealth has the same importance as wealth itself. Dishonesty, abuse of trust and earning of wealth through fraudulent ways and means may perhaps increase the status of an individual but the society suffers because of it on the whole. This leads to an unjust and oppressive economic system.


2021 ◽  
Vol 13 (15) ◽  
pp. 8147
Author(s):  
Sasiwimol Khawkomol ◽  
Rattikan Neamchan ◽  
Thunchanok Thongsamer ◽  
Soydoa Vinitnantharat ◽  
Boonma Panpradit ◽  
...  

A horizontal drum kiln is a traditional method widely used in Southeast Asian countries for producing biochar. An understanding of temperature conditions in the kiln and its influence on biochar properties is crucial for identifying suitable biochar applications. In this study, four agricultural residues (corncob, coconut husk, coconut shell, and rice straw) were used for drum kiln biochar production. The agricultural residues were turned into biochar within 100–200 min, depending on their structures. The suitability of biochar for briquette fuels was analyzed using proximate, ultimate, and elemental analysis. The biochar’s physical and chemical properties were characterized via bulk density, iodine number, pHpzc, SEM, and FTIR measurements. All biochars had low O/C and H/C ratios and negative charge from both carbonyl and hydroxyl groups. Coconut husk and shell biochar had desirable properties such as high heating value and a high amount of surface functional groups which can interact with nutrients in soil. These biochars are thus suitable for use for a variety of purposes including as biofuels, adsorbents, and as soil amendments.


2020 ◽  
Vol 6 (2) ◽  
pp. 43 ◽  
Author(s):  
Rubén González ◽  
Judith González ◽  
José G. Rosas ◽  
Richard Smith ◽  
Xiomar Gómez

Anaerobic digestion is an established technological option for the treatment of agricultural residues and livestock wastes beneficially producing renewable energy and digestate as biofertilizer. This technology also has significant potential for becoming an essential component of biorefineries for valorizing lignocellulosic biomass due to its great versatility in assimilating a wide spectrum of carbonaceous materials. The integration of anaerobic digestion and pyrolysis of its digestates for enhanced waste treatment was studied. A theoretical analysis was performed for three scenarios based on the thermal needs of the process: The treatment of swine manure (scenario 1), co-digestion with crop wastes (scenario 2), and addition of residual glycerine (scenario 3). The selected plant design basis was to produce biochar and electricity via combined heat and power units. For electricity production, the best performing scenario was scenario 3 (producing three times more electricity than scenario 1), with scenario 2 resulting in the highest production of biochar (double the biochar production and 1.7 times more electricity than scenario 1), but being highly penalized by the great thermal demand associated with digestate dewatering. Sensitivity analysis was performed using a central composite design, predominantly to evaluate the bio-oil yield and its high heating value, as well as digestate dewatering. Results demonstrated the effect of these parameters on electricity production and on the global thermal demand of the plant. The main significant factor was the solid content attained in the dewatering process, which excessively penalized the global process for values lower than 25% TS.


Author(s):  
Armin Silaen ◽  
Ting Wang

Numerical simulations of the coal gasification process inside a generic 2-stage entrained-flow gasifier fed with Indonesian coal at approximately 2000 metric ton/day are carried out. The 3D Navier–Stokes equations and eight species transport equations are solved with three heterogeneous global reactions, three homogeneous reactions, and two-step thermal cracking equation of volatiles. The chemical percolation devolatilization (CPD) model is used for the devolatilization process. This study is conducted to investigate the effects of different operation parameters on the gasification process including coal mixture (dry versus slurry), oxidant (oxygen-blown versus air-blown), and different coal distribution between two stages. In the two-stage coal-slurry feed operation, the dominant reactions are intense char combustion in the first stage and enhanced gasification reactions in the second stage. The gas temperature in the first stage for the dry-fed case is about 800 K higher than the slurry-fed case. This calls for attention of additional refractory maintenance in the dry-fed case. One-stage operation yields higher H2, CO and CH4 combined than if a two-stage operation is used, but with a lower syngas heating value. The higher heating value (HHV) of syngas for the one-stage operation is 7.68 MJ/kg, compared with 8.24 MJ/kg for two-stage operation with 75%–25% fuel distribution and 9.03 MJ/kg for two-stage operation with 50%–50% fuel distribution. Carbon conversion efficiency of the air-blown case is 77.3%, which is much lower than that of the oxygen-blown case (99.4%). The syngas heating value for the air-blown case is 4.40 MJ/kg, which is almost half of the heating value of the oxygen-blown case (8.24 MJ/kg).


2018 ◽  
Vol 37 (1) ◽  
pp. 544-557 ◽  
Author(s):  
Alejandra Saffe ◽  
Anabel Fernandez ◽  
Germán Mazza ◽  
Rosa Rodriguez

The use of energy from biomass is becoming more common worldwide. This energy source has several benefits that promote its acceptance; it is bio-renewable, non-toxic and biodegradable. To predict its behavior as a fuel during thermal treatment, its characterization is necessary. The experimental determination of ultimate analysis data requires special instrumentation, while proximate analysis data can be obtained easily by using common equipment but, the required time is high. In this work, a methodology is applied based on thermogravimetric analysis, curves deconvolution and empirical correlations for characterizing different regional agro-industrial wastes to determine the high heating value, the contents of moisture, volatiles matter, fixed carbon, ash, carbon, hydrogen, oxygen, lignin, cellulose and hemicellulose. The obtained results are similar to those using standard techniques, showing the accuracy of proposed method and its wide application range. This methodology allows to determine the main parameters required for industrial operation in only in one step, saving time.


2013 ◽  
Vol 805-806 ◽  
pp. 200-207
Author(s):  
Bing Zhang ◽  
Guang Wu Lu

Under different conditions,combustion characteristics of the single biomass,the single coal and the mixture of biomass and coal were analyzed by using thermogravimetric analyzer. Combustion characteristic parameters of the sawdust,the rice husk,the rice straw and the Baisha coal of Leiyang were studied,including ignition temperature,the maximum rate of combustion temperature,the burnout temperature and so on. The experimental results show that the biomass burning temperature is lower than the Baisha coal and there are two obvious weight loss phases in the combustion process of the biomass. However,there is only one in the coal. The ignition temperature and time of the coal can be reduced ,the temperature range of the entire combustion can be extended,the coal can be burnout more well and the fuel combustion characteristic can be optimized by blending combustion. With the increase of biomass mixing proportion, the ignition temperature of mixing samples was decreased more obviously. Moreover,when the biomass particle size becomes R200,compared with R90 particle size under the same blending ratio,its ignition temperature is more lower.


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