Indonesian Coal Research Articles

Techno-Economic Comparison of Coal Plants in India with Conventional and Advanced Power Generation Technologies Integrated with Calcium Looping Based CO2 Capture

India is a country which primarily depends on coal to satisfy the bulk of its energy as well as electricity needs. However, the emissions from coal power plants, mainly CO2 and also other pollutants such as SOx, NOx, PM and Hg have several harmful effects on the environment and also on the health of the people. Currently, the Govt. of India has laid out certain emission standards to control the emissions of SOx, NOx, PM and Hg from coal fired power plants. However, as of today, there are no regulations for control of emissions of CO2. But, looking at the broader picture of India’s continued dependence on coal in the future, it is necessary to identify appropriate technologies for CO2 capture, given the large scale impacts, CO2 emissions have at the global level. For carbon mitigation from coal plants in India there have been research studies mainly on implementing advanced steam parameters, using post combustion technologies such as MEA, Membrane, using pre-combustion technologies such as IGCC along with CO2 capture using physical or chemical solvents, and oxy-combustion based direct CO2 capture. However, there are a host of other technology options available for carbon mitigation from coal power plants in India, which can be explored to compare their performance with the available options. This paper deals with the techno-economic comparison of an existing supercritical plant operating on the conventional pulverized coal combustion (PCC) technology with the advanced power generation technology of fluidized bed combustion (FBC), both of which are integrated with CO2 capture using a Calcium looping (CaL) based sorbent. The analysis is performed for the coal plants using an Indian coal. Also comparison with imported coal varieties (Indonesian and South African coal) is carried out. The techno-economic analysis would give a comparison of some parameters such as i) energy penalty, ii) Levelized cost of electricity (LCoE), and iii) CO2 avoidance cost for the above power plant configurations which are integrated with the calcium looping based CO2 capture system.

Iron bearing oxide minerals separation from rare earth elements (REE) rich coal fly ash

Recovery of Rare Earth Elements (REE) from waste is an important alternative to solve global REE crisis. Therefore, coal fly ash containing REE becomes a potential candidate as an alternative source of REE. Indonesia has a large potential of coal resources, however unlike other type of coals which is rich in SiO2 and Al2O3, Indonesian coal contains significant amount of Fe2O3. As a consequence, fly ash resulted from burning Indonesia coal is also rich in iron oxides. The presence of high concentration of iron oxides will however reduce effectiveness of REE recovery from coal ash through hydrometallurgy process. Therefore, iron oxides in the coal fly ash needs, firstly, to separate preceding further REE separation. This study determined the optimal process conditions in the iron recovery process from coal fly ash. The variables studied were fly ash grain size, magnetic field strength and separation techniques. The iron recovery was determined by mean of the ratio of iron concentration after and before magnetic separation. Experimental results showed that increasing magnetic field strength and decreasing coal fly ash grain size in a wet separation will increase the recovery of magnetic iron component. Magnetic field strength of 4300 Gauss and grain size of -400 mesh were the optimal values in this study with iron recovery of 25.89%.

Ash formation characteristics of two Indonesian coals and the change of ash properties with particle size

It is difficult to maintain enough high circulating ash rate in circulating fluidized bed (CFB) boilers if they burn the Indonesian coals due to their low ash content. Hence, the ash formation data for these coals is of significance to assessing mass balance in CFB boilers. Two kinds of Indonesian coal that were burned in the 550 MW supercritical CFB boilers in Korea, Kideco and KCH, were tested with static combustion and cold sieving method to study their ash formation characteristics. Results showed that the average primary ash particle size of these two coals is quite fine overall and nearly no gangue exists. Besides, their attrition rate constant Kaf is much higher than that of some other bituminous or lean coals, and with the increase of particle size, the Kaf decays exponentially for Kideco, while it initially increases and then decreases for KCH. In addition, the physical and chemical properties of these two Indonesian coals' ash obviously change in particle size, including density, pore structure, chemical composition, etc. The larger ash particles are composed of some hard materials, such as quartz (SiO2) and mullite (Al6Si2O13). While some other materials with lower hardness value, like hematite (Fe2O3) and gehlenite (Ca2Al2SiO7), become major mineral components of smaller and softer ash particles. These results indicate that the difference of chemical compositions results in the discrepancy of attrition capability for different size ash particles.

Low-rank coal gasification using a bubbling fluidized bed reactor at low operating temperature

Coal gasification is one of coal utilizations that produces less CO2 emission than coal combustion. Coal gasification technology that has been used in Indonesia is generally a fixed bed gasification. Fixed bed is designed for high-rank coal and the majority of Indonesian coal is of a low-rank. Low ash and high moisture content of the Indonesian coal in a fixed bed can affect mechanical and thermal fragmentation, pressure drop, gas and particle flow distribution. The operation of gasifier may cause unstable condition. Another gasification technology is bubbling fluidized bed, which is operated above 1,200°C, so ash can melt. High operating temperature causes agglomeration and makes unstable gasification process. Therefore, in this study, low-rank coal is gasified in bubbling fluidized bed reactor at low operating temperature. The purpose of this study is to determine the optimal conditions of bubbling fluidized bed gasification. The research was conducted in bubbling fluidized bed coal gasification Process Development Unit (PDU) at Coal Utilization Technology Centre of R&D Centre of tekMIRA, Palimanan. Coal was fed continuously as many as 20 kg/hour into a gasifier then was gasified to produce gas using air as a gasifying agent and silica sand as a bed material at 850- 950°C. The produced gas from the gasification was analyzed using the Orsat Analyzer. A simulation using a ChemCAD 7.1 CC steady state was applied to validate the experiment result. From the analyzed result of yield gas composition, the produced CO and CO2 were about 10-15 wt%. Gas compositions that are close to criteria of producer gas, no agglomeration, and stable process condition during study indicate that bubbling fluidized bed gasification at low operating temperature is suitable to be applied as gasification technology for Indonesian low-rank coal.

The availability of Indonesian coal to meet the 2050 demand

Coal is the important energy source for industry and power plant in Indonesia. Its reserve is quite abundant around 28.5 billion tons. The Government of Indonesia issued the National Energy Policy (NEP) to target 25% of coal use of the national energy mix in 2050. The NEP directs the national energy management for the provision and utilization of primary energy. However, there are worries about the ability of coal reserve in accommodating the demand from domestic and export needs. The National Energy Council recommended coal production restriction policy for anticipation measures. This research investigated the current state of the coal reserves and the government policy to meet the target in 2050 using Vensim program. In the Vensim, a model was built to represent a coal supply - demand system. Several scenarios were simulated to analyze the relationship between the government policy and the coal reserve. The result shows that government intervention such as coal production restriction policy is needed to ensure Indonesia’s coal reserve can fulfill domestic demand for power generation and industry by 2050.

印尼煤堆存时间与热值变化的研究

印尼煤堆存时间与热值变化的研究

ESTIMASI PASOKAN BATUBARA UNTUK PLTU RENCANA DI PROVINSI KALIMANTAN BARAT

Abstrat - Coal is a cheap of fossil energy and encouraged in the framework of national energy diversification. Based on the Handbook of Energy and Economic Statistics of Indonesia 2016, Indonesia's coal reserves amounted to 32 billion tons which are spread on the islands of Sumatra and Borneo. Most of the domestic coal demands are currently used as fuel for PLTU to produce electricity. Based on the RUPTL PLN, to increase the reliability of the electricity system in West Borneo, the construction of non-fuel power plants such as the Parit Baru Power Plant (FTP1 and FTP2) and the Pantai Kura-Kura PLTU (FTP1). However, in West Borneo coal has not been exploited and coal reserves have also not been identified. To ensure the continuity of electricity supply in West Borneo Province, its need to estimated coal supply for the planned PLTU in West Borneo Province. which require data such as the coal specification data that will be used in the PLTU plan. After the data is collected, then the coal demands are calculated for each planne PLTU.

A CFD based comprehensive study of coal-fired updraft gasifier in ceramic industry

Coal is the most versatile conventional fuel which was used for many years by human beings for domestic purpose, in heavy industries and power plants. Particular in the ceramic industry, heating requirements have been satisfied by coal. Gasification of coal is the promising and convenient technology of converting the coal into synthesis gas which is a mixture of many combustible species. Gasifier used in present study was updraft type coal-fired gasifier which has been used by ceramic industries of Morbi (India). Experimental works have been carried out for various values of equivalence ratio (E.R.) from 0.24 to 0.36 and for specified boundary conditions. Also, numerical simulations have been compared with experimental works for the same E.R. values and boundary conditions. ANSYS Fluent software has been used to carry out numerical modeling and simulation. For coal-fired gasifier, Euler-Lagrange approach has been used for numerical modeling. The temperature distribution profile on gasifier wall has been compared with experimental and numerical data and it shows good agreement. Optimum E.R. for best syngas quality for Indonesian bituminous type coal was found as 0.28. Syngas composition has been determined at E.R. 0.28 with CO as 23.6 mol%, CO2 as 7.9 mol%, H2 as 19.6 mol%, H2O as 4.8 mol% and CH4 as 0.3 mol%. Carbon Convergence (C.C.) and Cold Gas Efficiency (C.G.E.) have also been determined in the present study with maximum values C.C. as 97.4% and C.G.E. as 87.5%. Also, the effect of steam/air ratio for E.R. 0.28 has been determined. The increment in steam/air ratio improves hydrogen production but resists overall gasification process.

The Hydrogen Adsorption Behavior of Mechano-Chemically Activated Carbon from Indonesian Low-rank Coal: Coupled Langmuir and Dubinin-Astakhov Isotherm Model Analysis

The Hydrogen Adsorption Behavior of Mechano-Chemically Activated Carbon from Indonesian Low-rank Coal: Coupled Langmuir and Dubinin-Astakhov Isotherm Model Analysis

No.1-8 インドネシア褐炭とインドネシア瀝青炭との混炭による自然発熱性緩和の検討

No.1-8 インドネシア褐炭とインドネシア瀝青炭との混炭による自然発熱性緩和の検討

Evaluation of combustion behaviour for Indonesian low-rank coals treated hydrothermally

Hydrothermal dewatering process has been made to produce dry-processed coals, which are comparable to bituminous coal. Two types of coals, i.e. low rank and high-rank coals. The low-rank coal came from West Papua while the high one was from Central Kalimantan. The behaviour of raw and processed coals were observed using thermogravimetry and differential scanning calorimetry techniques The change in chemical properties that are based on proximate, ultimate, calorific value and Fourier-transform infrared spectroscopy analyses are studied. Those are closely related to some combustion problems. This process was conducted in a laboratory scale using an autoclave with 5,000 ml/batch in capacity at the temperature of 300 and 330°C for one hour. The results indicate that the processed coals generally have a better combustion behaviour than that of the raw coals. The processed coals have a lower reactivity than that of raw ones, due to the higher ignition temperature (Tig), char burnout temperature (Tbo) as the end of combustion and maximum combustion rate (Rmax) of processed coals. The processing temperature of the process was a slight effect on combustion behaviour. The process is very effective to improve the quality of low-rank coal, nonetheless to high-rank coal, which has low moisture content and high calorific value, and the combustion behaviour of processed coals was not significantly changed.

Analisis pengaruh harga, PDB dan nilai tukar terhadap ekspor Batu Bara Indonesia

The objectives of this study are as follows: (1) To determine and analyze the development of prices, GDP, exchange rates, and exports of Indonesian Coal. (2) To find out and analyze the effect of prices, GDP, and exchange rates on Indonesia's coal exports. Based on the study results, (1) The average coal export in Indonesia from 2002-2016 was 11.91 percent per year. The development of Indonesian Coal prices from 2002-2016 was 17.77 percent per year. The average growth of the exchange rate from 2002-2016 was 2.18 percent per year. The average development of Indonesia's GDP from 2002-2016 was 5.47 percent. (2) The regression results show that the price of coal and the exchange rate has significantly affect Indonesia's coal exports. This can be seen from the t-count > t-table. Meanwhile, GDP does not have a significant effect on Indonesia's coal exports. Keywords: Price, GDP, Exchange rate, Coal export

Investigation of Indonesian low rank coals gasification in a fixed bed reactor with K2CO3 catalyst loading

Catalytic steam gasification is considered one of promising technologies for converting solid carbonaceous feedstocks into hydrogen-rich syngas, which is an important source of hydrogen for various industrial sectors. The K2CO3-catalyzed steam gasification of low rank coals (LRCs) was conducted in a fixed bed reactor for elucidating the effects of gasifying temperature and catalyst loading amount on hydrogen yield. Hydrogen-rich syngas can be obtained at gasifying temperature of 800 °C and loading amount of 10 wt% K2CO3. The loading amount of 10 wt% K2CO3 was the saturation point and provided a good gasification reactivity in catalytic steam gasification of three LRCs. The experimental data of these three LRCs were well described by the random pore model (RPM). The RPM fitted the experimental data at 800 °C better than the experimental data obtained at 700 °C and 600 °C. Reactivity index (R0.5), activation energy (Ea) and reaction rate constant (k) were also used to predict the characteristics of the K2CO3-catalyzed steam gasification process. Catalytic steam gasification utilizing the mixture of three LRCs as a feedstock was also investigated and displayed XC of 86.22% and 0.95 mol mol−1-C, indicating a good feasibility and potential industrial applications.

주식회사 삼탄의 인도네시아 진출과 사업 확장

주식회사 삼탄은 인도네시아 유연탄 생산을 주력으로 하는 기업으로 국내 민간 기업으로는 최대의 유연탄 생산 및 판매 규모를 달성하고 있다. 1970년 삼천리의 유성연 명예회장이 대한생명으로부터 삼척탄좌의 지분을 인수하며 설립한 후, 삼탄은 20여 년간 국내 연탄 시장을 이끌어 왔다. 하지만 석탄 시장 합리화 정책에 따라 국내의 연탄 산업이 쇠락해가면서 삼탄은 해외 시장으로 눈을 돌리고 인도네시아에 진출하여 사업을 이어가기로 결정한다. 1982년 인도네시아 유연탄광 사업에 컨소시엄의 형태로 진출한 후, 컨소시엄의 공동 투자자들이 사업에서 철수를 하는 동안 홀로 10년 간의 투자를 이어간 끝에, 삼탄은 인도네시아 파시르 지역의 광산 개발에 성공하게 된다. 현지 법인 KIDECO Jaya Agung을 연 매출 1,650백만U$ 규모로 성장시켰으나, 2003년 인도네시아 정부와 맺은 조광계약 (CCoW : Coal Contract of Word)에 따라 전체 지분의 51%를 인도네시아 현지의 파트너에 매각하여 회사의 형태를 Joint venture로 변화시키게 된다. 인도네시아 정부가 지속적인 자원민족주의 정책을 펴면서 광산 개발 사업만으로는 수익성이 악화되면서 삼탄은 자원 개발 관련 공정의 수직적 계열화를 진행하고, 자회사들을 통해서 모든 생산 공정을 관리하게 된다. 삼탄은 인도네시아 현지의 정치/사회적 환경이 변화함에 따라 새로운 성장 동력을 찾기 시작하였고, 2000년대 중반 이후 꾸준히 새로운 사업 기회에 투자를 진행하였다. 그 결과 팜 플렌테이션(THEP), LPG 가스 생산(PSG), 석탄화력발전(CEP) 등 성공적으로 사업 영역 확장을 이뤄내고 있다.BR 본 연구에서는 주식회사 삼탄의 사례를 통해 국내 자원개발 전문 업체의 해외 진출 및 현지 운영 과정과 신규 사업 확장 전략을 확인해 보고자 한다. 특히 정부 정책과 같은 외부적인 요인에 따라 해외 진출을 진행한 기업이 해외시장에서 수직적/수평적 계열화를 이루며 사업을 확장하는 과정을 관찰할 수 있다. 연구를 위하여 수 차례 회사 관계자와 인터뷰를 진행하였으며, 내부 자료도 분석에 활용하였다.

Catalytic effect of ion-exchanged calcium on steam gasification of low-rank coal with a circulating fluidized bed reactor

Calcium ion exchange was performed in Indonesian low-rank coal using saturated aqueous solutions of Ca(OH)2 at 30.0 ± 0.1 °C without pH adjustment. The Ca2+ concentration and pH were monitored during ion exchange. A coal product was obtained with 3.2 mass% Ca2+. Gasification of the ion-exchanged samples was conducted in a circulating dual bubbling fluidized bed (CDBFB) reactor at 700 °C, 800 °C, and 900 °C. Coal carbon conversion into carbonaceous gases (CO, CO2, CH4, and C2 hydrocarbons) using the Ca2+-exchanged coal achieved 78% at 900 °C in the CDBFB. The Ca catalyst led to the greatest rate enhancement at 800 °C, resulting in a twofold increase in the gas product yield compared to that without Ca.A comparison of carbon conversion between the CDBFB and fixed-bed reactors revealed that the conversion value using the CDBFB at 700 °C was very small. Regarding an examination of this influence in detail, it seems that the existing H2 adhered primarily to the active sites of the char, and the use of Ca2+-exchanged coal led to a reverse shift reaction.

Study on the Formation of Microglass Beads during Staged Combustion

The effect of ambient temperature on the formation of microscopic (micro) glass beads was studied using a drop tube furnace in a weak reducing atmosphere, under conditions of controlled (staged) combustion. Indonesian coal, which has a high ash content, was used, and the experimental temperatures ranged from 1300 to 1500 °C. The fly ash was analyzed by an X-ray diffractometer and a scanning electron microscope, and the yield of cenospheres with density lower than 1 g/m3 was determined by wet separation. The experimental results showed that the content of quartz in the fly ash decreased with increasing experimental temperature, while the content of the glass phase barely changed. The particles gradually assumed a spherical shape, with an average aerodynamic diameter of approximately 7 μm. The proportion of cenospheres with a density less than 1 g/m3 gradually increased with increasing temperature. On the basis of the above analysis, it can be qualitatively concluded that increased ambient temperature promo...

Effect of Fe2O3 on steam gasification of subbituminous coal/woody biomass mixture

AbstractThis study investigated the steam gasification of Indonesian Adaro coal and Japanese cedar mixed in a 1:1 ratio with the physical addition of 10 wt% Fe2O3 in 50 vol% H2O at ambient atmospheric pressure and 800°C for 1 h. The primary objective of this work was to examine the effectiveness of an iron catalyst on the interaction between Indonesian Adaro coal and Japanese cedar. The study demonstrated that the H2 evolution amount for co‐gasification of Japanese cedar and Adaro coal (with 1:1 ratio in weight) without a Fe catalyst was 100 mmol/g‐char. However, the H2 evolution amount for co‐gasification with the addition of Fe2O3 was 152 mmol/g‐char. The increase in the co‐gasification for H2 evolution was based on a change in the char structure during pyrolysis and gasification.

Feasibility Comparison of Drying and Briquetting Processes Using Palm Oil Residue Based on a Pilot-scale Test with Indonesian Low-rank Coal

ABSTRACT The feasibility of drying/briquetting and simple drying processes for an Indonesian low-rank coal are quantitatively compared, based on a 15 t pilot-scale experiment. Palm acid oil was applied, via the CUPOTM process, as the coating agent after drying and as a binding agent for briquettes, tested at ratios of 0.0%, 0.5%, and 1.0%. Sales prices and operating costs are based on current Indonesian government regulations and market conditions. The PT Ganda Alam Makmur coal mine, in East Kalimantan, Indonesia, was chosen for the case study. A briquetted sample dried using 0.5% palm acid oil performed better than other treatments. Abbreviations: ASTM: American Society of Testing and Materials; BCB: Binderless coal briquette; BCM: Bank cubic meter (earth volume before digging); BPPT: Badan Pengkajian dan Penerapan Teknologi,(Indonesian Agency for the Assessment and Application of Technology); CapEx: Capital expenditure; CPO: Crude palm oil; CUPO: Coal upgrading with palm oil; CV: Calorific value; DAB: Drying and briquetting process; DAF: Dry ash free basis; FOB: Free on board; GAM: PT Ganda Alam Makmur, a coal mine in Indonesia; GAD: Air dried basis; GAR: As received basis; HRC: High rank coal; IM: Inherent moisture; LRC: Low rank coal; PAO: Palm acid oil, a POR, obtained from oily residue from a CPO mill; POR: Palm oil residue; STD: Steam tube dryer; TM: Total moisture; UBC: Upgraded brown coal

Primary Fragmentation Behavior of Indian Coals and Biomass during Chemical Looping Combustion

Devolatilization and fragmentation are important physical phenomena occurring during solid fuel chemical looping combustion (CLC). Primary fragmentation during devolatilization strongly affects the rate of fuel conversion, emissions, and fine particulates generation in a fuel reactor of a fluidized bed CLC unit, thus forming a critical design input. The present study focuses on investigating the primary fragmentation behavior of large coal and biomass (wood) particles during the devolatilization phase of CLC. Three types of coals (two Indian coals, one Indonesian coal) and one type of Casuarina wood of three sizes in the range of 8–25 mm, at different fuel reactor bed temperatures (800, 875, and 950 °C) are studied for primary fragmentation. Iron ore with 64% Fe is used as the oxygen carrier bed material, with steam as the fluidizing medium in the fuel reactor. The fragmentation behavior is expressed in terms of the number of fragments, fragmentation index, frequency of fragmentation, and particle size di...

Carbon dioxide emission factor estimation from Indonesian coal

Climate change will become the priority for the air quality management. It focuses more on carbon dioxide emission. Indonesia which has power generation dominated by coal combustion is expected to develop the national CO 2 emission factor. Due to the high variation in Indonesia coal rank and its growing magnitude in CO 2 emission caused by the future coal-fired power plant development, the characteristic emission value becomes an important concern. The method used in this study is developed from the IPCC Guidelines for Energy. The conversion unit plays an important role in the calculation method. The result shows that the higher in C content, the lower in its CO 2 emission factor. It means that coal classified as high C content or high heating value will produce low carbon dioxide emission factor. The average CO 2 emission factor obtained in Indonesian coal is 99,718 kg CO 2 /TJ with an average value of carbon content 27.2 kg C/GJ, and NCV equal to 19.8 TJ/Gg. Coal rank is categorized as lignite to subbituminous or bituminous.