A Study on the Hard Coal Grindability Dependence on Selected Parameters

A very important aspect of proper preparation of the coal mixture for the coking process is its appropriate grinding. One of the parameters describing the energy input required for grinding is the Hardgrove index. This research was undertaken to determine the dependence of the Hardgrove grindability index on selected physicochemical properties of coal. The Hardgrove grindability index was determined using the available methods described in the standards, and the dependence on selected parameters was examined. A clear positive correlation with calorific value and smaller (also positive) correlations with moisture content and free swelling index was obtained. A slight negative correlation was also obtained with sulfur content.

FINANCIAL ANALYSIS OF GREEN PETROLEUM COKE AS A COAL BLEND IN STEEL INDUSTRY TO SUPPORT NATIONAL ENERGY SECURITY

Green Petroleum Coke (GPC), produced by Pertamina RU II Dumai, is the product of refined petroleum, which still has good quality but has not been utilized to its full potential. Such as Sulfur 0.5%; FC 86.03%; Ash 0.10%; VM 13.82%; Moist 10, 52%; and the calorific value of 7500 kcal/kg. Therefore, one effort that can do is diversification, namely the use of GPC as a mixture of other fuels (fossil) to increase the selling value of GPC. This diversification is also in line with the national energy policy in PP. 79/2014 that the program aims to increase the availability of national energy sources. This study aims to determine the feasibility of using GPC as a coal mixture in Industry (Krakatau Steel) with an overview of economic aspects. Data obtained by qualitative methods consisting of interviews, observation, and documentation. Based on the research results from 2 scenarios, both scenario 1 (GPC 4%) and scenario 2 (GPC 18%), it is found that the NPV is positive, IRR is above the discount rate, and BCR> 1. Thus, the use of GPC as a coal mixture is considered feasible to run and can support national energy security.Keywords: Diversification, Feasibility, Petroleum Coke, Investment DecisionJEL: G11, G32

Valuation slagging factors and greenhouse gases emissions of paper mill reject and coal

There are quite a lot of paper mill rejects (PMR) as a by-product of paper mills and have not been utilized, currently. The purpose of this study is to evaluate the characteristics of paper mill reject (PMR) to coal and natural biomass and estimate the greenhouse (GHG) emissions of PMR and coal. Coal and PMR taken from five paper mills were analyzed for the content of moisture, proximate parameter (ash, volatile matter, fixed carbon), sulfur (S), gross calorific value (GCV), ash mineral and ash fusion temperature (AFT). The slagging factors of materials were calculated and evaluated. The resulting greenhouse gasses (GHG) emissions was also estimated. The results show that with the high calorific value, low ash and sulfur content of PMR, it has the potential to be used as a coal mixture for boiler fuel. It is very beneficial for the environment due to the low SO2 emissions. PMR has the characteristics of a low slagging index (SI), high fouling index (FI) and Slag Viscosity Index (SVI) which is almost similar with biomass, empty fruit bunches (EFB) and rice husk. The use of PMR as a coal mixture in paper mills in the amount of 10,285 ton/year can reduce greenhouse gases of 63.5 tons CO2-equivalent/year.

3D-LDA diagnostics of a swirled flow in the model of an improved four-vortex furnace

The three-component Laser Doppler Anemometry method (3D-LDA) was used to study the internal aerodynamics of an experimental model of a promising furnace with a four-vortex scheme for burning coal fuel. Distributions of the averaged velocity and velocity fluctuations are obtained. There are no the pronounced peaks in the spectrum of velocity fluctuations, so we can speak about the stability of the investigated flow. The studied model is characterized by a high level of velocity fluctuations, provided for effective mixing of the pulverized coal mixture in the combustion chamber of the furnace.

Types and Composition of Biomass in Biocoke Synthesis with the Coal Blending Method

The steelmaking industry requires coke as a reducing agent, as an energy source, and for its ability to hold slag in a blast furnace. Coking coal as raw coke material is very limited. Studying the use of biomass as a mixture of coking coal in the synthesis of biocoke is necessary to reduce greenhouse gas coal emissions. This research focuses on biomass and heating temperature through the coal blending method to produce biocoke with optimal mechanical properties for the blast-furnace standard. The heating temperature of biomass to biochar was evaluated at 400, 500, and 600 °C. The blending of coking coal with biochar was in the compositions of 95:5, 85:15, and 75:25 wt.%. A compacting force of 20 MPa was employed to produce biocoke that was 50 mm in diameter and 27 mm thick using a hot cylinder dye. The green sample was heated at 1100 °C for 4 h, followed by quenching with a water medium, resulting in dense samples. Increasing heating temperature is generally directly proportional to an increase in fixed carbon and calorific value. Biocoke that meets several blast-furnace criteria is a coal mixture with coconut-shell charcoal of 85:15 wt.%. Carbonization at 500 °C, yielding fixed carbon, calorific value, and compressive strength, was achieved at 89.02 ± 0.11%; 29.681 ± 0.46 MJ/kg, and 6.53 ± 0.4 MPa, respectively. This product meets several criteria for blast-furnace applications, with CRI 29.8 and CSR 55.1.

Analysis of the Influence of Biomass Addition in Coal Mixture for Metallurgical Coke Production

Metallurgical coke is a common material used for hot metal production in blast furnaces. In addition to the fuel function, it has a physical assignment, supporting the load inside the reactor, and chemical, supplying carbon to hot metal. However, due to growing discourse on environmental issues, the production of hot metal via coke blast furnace has been in evidence. This process is responsible for about 70% of CO2 emissions in steelmaking. On the other hand, biomasses are materials that are available in different ways in nature and considered neutral in CO2 emissions since they absorb this gas and release oxygen in the photosynthesis process. Thus, a viable alternative in the short term is the partial replacement of the coal used in coke production with biomass, which would generate environmental gains, and guarantee the sustainable production. Therefore, this work aims to show several published researches using biomass in coke production. The effects that biomass has on the properties of coke will be emphasized, and at the end, an environmental analysis will be shown with the possible use of biomass. It will be possible to see that it is possible to substitute between 2 and 10% of the coal for biomass, producing coke with the characteristics required in the blast furnace.

PENETAPAN NILAI KALORI DALAM BATUBARA DENGAN KALORIMETER PARR 6200

Determining Calory Value of Coal With Calorimeter Parr 6200 Coal is a source of energy utilized by the process of making cement. This type of coal determines the quality and calorific value of the coal. Determination of calorific value on coal is done by using calorimeter. Coal types studied were A and B coal mixture with ratio 80:20, 70:30, 60:40, and 50:50. The results showed that the mixture of A and B coal with a ratio of 80:20, 70:30, 60:40, and 50:50 can be used for combustion in the manufacture of cement in the furnace because it has a calorific value above 6000 in accordance with the standards of the cement factory . Water content affects the calorific value of coal, the higher of moisture content, the lower the heating value.Keywords: Coal, Calorimeter, Heat valueABSTRAK Batubara merupakan sumber energi yang dimanfaatkan oleh proses pembuatan semen. Jenis batubara menentukan kualitas dan nilai kalor dari batubara tersebut. Penentuan nilai kalor pada batu bara dilakukan dengan menggunakan kalorimeter. Jenis batubara yang diteliti yaitu Campuran batubara A dan B dengan perbandingan 80:20, 70:30, 60:40, dan 50:50. Hasil penelitian menunjukkan bahwa campuran batubara A dan B dengan perbandingan 80:20, 70:30, 60:40, dan 50:50 dapat digunakan untuk pembakaran dalam pembuatan semen di tanur bakar karena memiliki nilai kalori diatas 6000 sesuai dengan standar perusahan pabrik semen. Kadar air mempengaruhi nilai kalori batubara, yaitu semakin tinggi kadar air semakin rendah nilai kalor.Kata Kunci: Batu Bara, Kalorimeter, nilai kalor