The impact of mineral matter in coal on its combustion, and a new approach to the determination of the calorific value of coal

Shirazi, Ahmad Reza; Börtin, Olle; Eklund, Lars; Lindqvist, Oliver

doi:10.1016/0016-2361(95)92661-o

Cited by 47 publications

(14 citation statements)

References 2 publications

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“…Finally, the ash (mineral matter) has a negative impact on the environment due to the combustion of lignite in power plants, as well as during other methods of its utilization, such as gasification, carbonisation, and liquefaction (e.g. Shirazi et al 1995, Gülen 2007, Naworyta 2008, Bielowicz 2013. Therefore, the study of ash content in lignite seams is important, with many potential benefits for both industry and the environment.…”

Section: Interpretation and Discussionmentioning

confidence: 99%

Variation of lignite ash in vertical and horizontal sections of mining wallsin the Konin Lignite Mine, central Poland

Chomiak

2020

geol

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This paper focuses on the variations of lignite ash along selected sections and mining walls from three lignite opencast mines in central Poland. They are owned by the Konin Lignite Mine, where the first Mid-Polish lignite seam is being mined to produce electricity. Ash content in lignite is important because ash lowers the calorific value of the lignite. The results obtained are based on 266 samples of lignite collected from the Drzewce, Tomisławice, and Jóźwin IIB opencasts. All samples were tested according to ISO 1171 standard procedures, that is, they were first burned at a temperature of 850°C, then the ash content was determined on a dry basis (Ad), be-fore the basic statistical parameters were calculated. The studied lignite seam is characterised by a variable distribution pattern of ash both along selected vertical sections and lignite walls, as well as between the three open-casts. The ash content of individual samples ranged from 6.5 to 69.8 wt%, while the average content in opencast mines varied from 9.7 to 17.6 wt%. The coefficient of variation is large (80.23–96.33%) in the case of the Drzewce and Tomisławice, and low to average (14.53–37.75%) in the case of Jóźwin IIB. Significant ash enrichment of some beds is interpreted in this article as a consequence of floods occurring in a Mid-Miocene mire (backswamp), but also of chemical precipitation. When lignite is burned to generate electricity, a relatively large amount of ash is produced. Therefore, recognition of ash content in lignite, in addition to the chemical composition and phase of ash, is recommended to better protect the environment. At the first stage of protection, it can be best achieved by analysing field samples for ash content.

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Section: Interpretation and Discussionmentioning

confidence: 99%

Variation of lignite ash in vertical and horizontal sections of mining wallsin the Konin Lignite Mine, central Poland

Chomiak

2020

geol

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“…The currently used methods allow the combustion of coal with a dry ash content below 40%. According to Shirazi et al [47], the amount and chemical composition of mineral matter significantly reduces the amount of obtained energy. This is due to the fact that part of it is used for heating the non-combustible material.…”

Section: Oxide Composition Of Ash and Its Propertiesmentioning

confidence: 99%

Ash Characteristics and Selected Critical Elements (Ga, Sc, V) in Coal and Ash in Polish Deposits

Bielowicz

2020

Resources

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The chemical composition of coal ash and the content of the critical elements Ga, Sc, and V in coal and ash are examined herein. In this study, lignite and bituminous coal from Polish deposits were used. The coals were subjected to ultimate and proximate analysis; the petrographic composition was determined based on maceral groups. The chemical composition of ash and the content of critical elements were determined using ICP-MS. The obtained results were correlated and Pearson’s linear correlation coefficient was determined. Based on the correlation analysis, the relationship between the chemical composition of ash and the proximate and ultimate analyses was demonstrated. The content of selected critical elements in the tested deposits was lower than the Clarke value in coal. However, in some deposits these contents are much higher in coal ashes. The higher levels of Ga, V, and Sc in the ash are associated with Al2O3. Therefore, it can be stated that ashes can be a potential source of some raw materials. The highest concentrations of critical elements in coal and ash were recorded in the Lublin Coal Basin. Supra-Clarke contents of Ga, V, and Sc were recorded in the Bogdanka coal mine.

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“…In this study, the calorific value was measured not calculated. The CV is defined as the amount of heat evolved when a unit weight of biomass is burnt completely and the combustion products cooled to a standard temperature of 298 K (Shirazi et al, 1995;Ahmed et al, 2019).…”

Section: Calorific Valuementioning

confidence: 99%

Assessment of Peat Deposits in Rwanda

Mugerwa¹,

Ehinola²,

Oladosu³

et al. 2020

GEP

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The peat deposits in Rwanda are distributed over an area of 50,000 ha and were formed about the end of last glaciations period. However Akanyaru peat is 20,000 years old and contains peat of glacial and postglacial period. The studies show that Rwanda has 155 million tons of dry peat which can generate electrical energy and this deposit is sufficient to meet country's vast energy requirements for 30 years. Hence, it was felt necessary to map prospective locations of peat and their energy potential. The result of the study and assessment of peat to power in Rwanda show that the average in-situ ash content, in-situ moisture content and in-situ bulk density of the collected peat samples are 36 wt%, 70.8 wt% and 1112 kg/m 3 respectively. Their average thickness ranges from 0.9 to 7.8 m. In Finland, peat was used as fuel in 1996 and produced 10% of total installed capacity. Rwanda has the same operational peat power plant in Gishoma: Rusizi District generating 15 MW connected to the national electrical grid. A peat-fuelled power plant is under construction and is expected to generate 80 MW. This plant, once completed, is expected to connect 50% more households into national grid. Thus, this effort along with other projects will increase electrical power from 208 MW to 563 MW in 2024. Peat deposit is expected to generate 500 Megawatt electrical powers for 30 years. Although an effort was done to use peat as fuel, the power plant is still vulnerable to the lack of good quality of dry peat to operate and thus efforts are on to develop suitable technology for exploitation.

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The impact of mineral matter in coal on its combustion, and a new approach to the determination of the calorific value of coal

Cited by 47 publications

References 2 publications

Variation of lignite ash in vertical and horizontal sections of mining wallsin the Konin Lignite Mine, central Poland

Variation of lignite ash in vertical and horizontal sections of mining wallsin the Konin Lignite Mine, central Poland

Ash Characteristics and Selected Critical Elements (Ga, Sc, V) in Coal and Ash in Polish Deposits

Assessment of Peat Deposits in Rwanda

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