The study of effects of
14TH REGIONAL SYMPOSIUM ON CHEMICAL ENGINEERING 2007
ISBN 978-979-16978-0-4
The Study Of Effects Of Electrolysis Variables To
The Inherent Moisture Content In Brown Coal
A. M.DJONI BUSTAN a. B. MARDWITA
a
Departement of Chemical Engineering University of Sriwijaya, Indonesia
a
Graduate School University of Sriwijaya
a
Jalan Padang Selasa N0.524, Bukit Besar, Palembang 30139, Indonesia
a
Telp: (0711)352132 – 354222 Fax : (0711) 317202 – 320310
a
E-mail : djajashanta@yahoo.co.id
ABSTRACT
This research uses Electrothermal Dewatering Brown Coal (EDBC) technology to reduce the inherent
moisture content in brown coal using kerosene as coal slurry medium maker. The purpode of this
research is to learn the effect of voltage and process temperature to the increasing of coal product quality.
From this research analysis of product at energy development and Mining Depatement of South
Sumatera province shown that lowness inherent moisture product of experiment as 2.64% (adb) with
beginning inherent moisture 12.09% (adb) that happen deriving inherent moisture as big as 78.16%.
Lowness inherent moisture got from experiment use ratio of coal and kerosene at 1 : 2 and variable of
electrolysis at 12 volts.
Keywords : Electrothermal dewatering brown coal technology, inherent moisture content, electrolysis.
I. INTRODUCTION
Indonesia is one of development country that try to reduce the crude oil consuming. With the potency
of energy, Indonesia has no difficulty to subsitute crude oil. One of the energy is coal. The reserve in Indonesia
is big enough 38.87 million tons or about 38% from total energy mix Indonesia [1]. Supporting from Energy and
Mining Departement gives bright future for the use of coal. Main problem that occur in Indonesia mining is the
water content in coal that cause the cost of transportation become expensive. Besides that, it makes the
efficiency of burning become lower.
Many experiment were carried out such as Evans et al, took coal sample from Victoria (Australia)
using hot water as drying medium. The process took place with coal compound heating and water at temperature
350 oC, high pressure causing the water vaporization naturally in coal pores. This method known as Hot Water
Drying method (HWD) and in 1979 patented by D.G Evans and S.R.Seimon [2]. Slurry Dewatering technique
or known as Kakogawa process had done by NEDO (Japan government) together with Coal and Minerals
Development Technology and Research Center (TeKMIRA) Energy Development and Mining Departement of
Bandung [3]. This process uses temperature 140-150 oC and pressure 100-350 Kpa, and be able to reduce the
inherent moisture content in brown coal until 5%. There is technology that is used to increase the efficiency of
electrical generator using brown coal as fuel [4]. The coal get into drying process before furnace chamber.
Combining coal drying process with electrical generator give significant efficiency to the electrical generator .
But the drying process must be efficient, with other words it must be cheap technology and can be applied. The
increasing of coal quality can reduce the CO2 gas emission or CO in coal combustion process. Indonesia has
tried to develop coal technology, one of the technology is Upgrading Brown Coal Technology [5] . This
technology is used to reduce the moisture content whether the water is on surface or in the pores of coal. One of
the upgrading brown coal method that sometime is used is thermal dewatering [6]. Thermal dewatering method
is reducing moisture content in coal using heat from any resources. Most of this method use heat from briqutte
burning or electrical generator furnace. Thermal dewatering is mostly used in coal treatment raw material.
Electrolysis process in upgrade brown coal is a process where there is electrons addition into the coal mix and
kerosene as the solvent to make the coal main structure of van der walls weak so the coal mix in an unstable
condition. The process is a combination between physics and chemistry. Electrolysis process use kerosene as
electron transfer medium to coal structure. But electrons can not flow by it selves. It needs water compound and
metal compound in coal main structure [7].
Yogyakarta-Indonesia, 4-5th December 2007
Chemical Engineering Department , Gadjah Mada University
14TH REGIONAL SYMPOSIUM ON CHEMICAL ENGINEERING 2007
ISBN 978-979-16978-0-4
II. RESEARCH METHOD
This research is used to analyze the effect of process variables to the increasing of brown coal (lignite)
quality [8]. Generally this research consists of raw materials preparation, coal quality sampling analysis,
electrothermal dewatering brown coal process (EDBC) and product analysis in laboratory. Coal particle ± 50
mesh, coal-kerosene ratio are 1:10, 1:20, and 1:40. The kerosene compound can reach inside the coal structure,
after 15 minutes circulated process, kerosene and coal particle will be separated by the density for 1 hour
aglomeration. Wet coal as product is dried by the temperature 160 oC for 2 hours and the product will be
analyzed in laboratory to find out the inherent moisture content.
Coal
Slurry making
Coal-kerosene
separating
Water Reducing
Kerosene
Recovery
Waste water
Kerosene recycling
UBC Product
(powder)
Fresh Kerosene
Fig.1.1. Diagram Block of Electrothermal Dewatering
Brown Coal (EDBC) Process
III. RESEARCH RESULTS AND ANALYSIS
From the graphic as shown below, for different coal-kerosene ratio there is same phenomena for the
process from 0 to 4 volts decreasing of inherent moisture content significantly (%adb) and then there is
increasing at 8 volts and also at 12 volts. This phenomena perhaps caused by voltage. The graphic shown
sinusoidal pattern as a electrical wave from electrolysis resources process. The percentage of inherent moisture
content is being different for each coal ratio caused by electron suppy from electrolysis process.
8
Inherent Moisture (% adb)
7
6
5
4
3
Rasio Batubara : Kerosin = 1 : 10
Rasio Batubara : Kerosin = 1 : 20
Rasio Batubara : Kerosin = 1 : 40
2
0
2
4
6
8
10
12
14
Voltase (Volt)
Fig 1.2. Electrolyse variable (voltage) to decreasing inherent moisture
content (%adb) Process temperature 50 oC
Yogyakarta-Indonesia, 4-5th December 2007
Chemical Engineering Department , Gadjah Mada University
14TH REGIONAL SYMPOSIUM ON CHEMICAL ENGINEERING 2007
ISBN 978-979-16978-0-4
IV. CONCLUSIONS
Electrolysis give significant effect to the decreasing of inherent moisture content and increasing of coal heating
value . The highest decreasing of inherent moisture content is at coal-kerosene ratio 1: 20, temperature 70 oC
and voltage 12 volts with percentage of decreasing achieved 78.16%.
REFERENCES
[1] Almu’minin Syarif, 2005, “Pengaruh Thermal Dewatering Batubara terhadap Kualitas Batubara”,
Laporan Tugas Akhir Jurusan Teknik Pertambangan Fakultas Teknik Universitas Sriwijaya, Inderalaya.
[2] Evans D.G.; and Seimon S.R. 1979. US patent number 3.552.031
[3] Syarifudin and Rr. Herminuke E.H, 2004 “Quality Improvement of Musi Bayuasin Low Rank Coal with
Deriving Inherent Moisture In Upgraded Brown Coal Process” Proceding of HEDS Seminar on Science &
Tecnology, Jakarta.
[4] Chaffe dan I Yarovshy, 2005, “The Chemistry of Coal-Water Interactions: and Theoritical and Experimentl
Investigation”, CRC for Clean Power from Lignit, Monash University dan RMIT University, Melbourne.
[5] T. Deguchi, T. Shigehisa and K. Shimasaki, 1999, “Study on Upgrading Brown Coal Process for
Indonesian Low Rank Coal”, Kobe Steel, Ltd., Procedings of 10th ICCS, Jepang.
[6] Meyers, Robert. A, 1981, “Coal Handbook”, Marcell Dekker. Inc, New York.
[7] Berkowitz. N, 1985, “The Chemistry of Coal: Coal Science and Technology”, Volume 2, Elvessier
Publicatin.Co, Amsterdam.
[8] Bahrin, D.; and Bustan, M.D. 2006. Thesis: The Study Of Effects Of Electrolysis Variables To The Inherent
Moisture Content In Brown Coal. Palembang: University of Sriwijaya.
Yogyakarta-Indonesia, 4-5th December 2007
Chemical Engineering Department , Gadjah Mada University
ISBN 978-979-16978-0-4
The Study Of Effects Of Electrolysis Variables To
The Inherent Moisture Content In Brown Coal
A. M.DJONI BUSTAN a. B. MARDWITA
a
Departement of Chemical Engineering University of Sriwijaya, Indonesia
a
Graduate School University of Sriwijaya
a
Jalan Padang Selasa N0.524, Bukit Besar, Palembang 30139, Indonesia
a
Telp: (0711)352132 – 354222 Fax : (0711) 317202 – 320310
a
E-mail : djajashanta@yahoo.co.id
ABSTRACT
This research uses Electrothermal Dewatering Brown Coal (EDBC) technology to reduce the inherent
moisture content in brown coal using kerosene as coal slurry medium maker. The purpode of this
research is to learn the effect of voltage and process temperature to the increasing of coal product quality.
From this research analysis of product at energy development and Mining Depatement of South
Sumatera province shown that lowness inherent moisture product of experiment as 2.64% (adb) with
beginning inherent moisture 12.09% (adb) that happen deriving inherent moisture as big as 78.16%.
Lowness inherent moisture got from experiment use ratio of coal and kerosene at 1 : 2 and variable of
electrolysis at 12 volts.
Keywords : Electrothermal dewatering brown coal technology, inherent moisture content, electrolysis.
I. INTRODUCTION
Indonesia is one of development country that try to reduce the crude oil consuming. With the potency
of energy, Indonesia has no difficulty to subsitute crude oil. One of the energy is coal. The reserve in Indonesia
is big enough 38.87 million tons or about 38% from total energy mix Indonesia [1]. Supporting from Energy and
Mining Departement gives bright future for the use of coal. Main problem that occur in Indonesia mining is the
water content in coal that cause the cost of transportation become expensive. Besides that, it makes the
efficiency of burning become lower.
Many experiment were carried out such as Evans et al, took coal sample from Victoria (Australia)
using hot water as drying medium. The process took place with coal compound heating and water at temperature
350 oC, high pressure causing the water vaporization naturally in coal pores. This method known as Hot Water
Drying method (HWD) and in 1979 patented by D.G Evans and S.R.Seimon [2]. Slurry Dewatering technique
or known as Kakogawa process had done by NEDO (Japan government) together with Coal and Minerals
Development Technology and Research Center (TeKMIRA) Energy Development and Mining Departement of
Bandung [3]. This process uses temperature 140-150 oC and pressure 100-350 Kpa, and be able to reduce the
inherent moisture content in brown coal until 5%. There is technology that is used to increase the efficiency of
electrical generator using brown coal as fuel [4]. The coal get into drying process before furnace chamber.
Combining coal drying process with electrical generator give significant efficiency to the electrical generator .
But the drying process must be efficient, with other words it must be cheap technology and can be applied. The
increasing of coal quality can reduce the CO2 gas emission or CO in coal combustion process. Indonesia has
tried to develop coal technology, one of the technology is Upgrading Brown Coal Technology [5] . This
technology is used to reduce the moisture content whether the water is on surface or in the pores of coal. One of
the upgrading brown coal method that sometime is used is thermal dewatering [6]. Thermal dewatering method
is reducing moisture content in coal using heat from any resources. Most of this method use heat from briqutte
burning or electrical generator furnace. Thermal dewatering is mostly used in coal treatment raw material.
Electrolysis process in upgrade brown coal is a process where there is electrons addition into the coal mix and
kerosene as the solvent to make the coal main structure of van der walls weak so the coal mix in an unstable
condition. The process is a combination between physics and chemistry. Electrolysis process use kerosene as
electron transfer medium to coal structure. But electrons can not flow by it selves. It needs water compound and
metal compound in coal main structure [7].
Yogyakarta-Indonesia, 4-5th December 2007
Chemical Engineering Department , Gadjah Mada University
14TH REGIONAL SYMPOSIUM ON CHEMICAL ENGINEERING 2007
ISBN 978-979-16978-0-4
II. RESEARCH METHOD
This research is used to analyze the effect of process variables to the increasing of brown coal (lignite)
quality [8]. Generally this research consists of raw materials preparation, coal quality sampling analysis,
electrothermal dewatering brown coal process (EDBC) and product analysis in laboratory. Coal particle ± 50
mesh, coal-kerosene ratio are 1:10, 1:20, and 1:40. The kerosene compound can reach inside the coal structure,
after 15 minutes circulated process, kerosene and coal particle will be separated by the density for 1 hour
aglomeration. Wet coal as product is dried by the temperature 160 oC for 2 hours and the product will be
analyzed in laboratory to find out the inherent moisture content.
Coal
Slurry making
Coal-kerosene
separating
Water Reducing
Kerosene
Recovery
Waste water
Kerosene recycling
UBC Product
(powder)
Fresh Kerosene
Fig.1.1. Diagram Block of Electrothermal Dewatering
Brown Coal (EDBC) Process
III. RESEARCH RESULTS AND ANALYSIS
From the graphic as shown below, for different coal-kerosene ratio there is same phenomena for the
process from 0 to 4 volts decreasing of inherent moisture content significantly (%adb) and then there is
increasing at 8 volts and also at 12 volts. This phenomena perhaps caused by voltage. The graphic shown
sinusoidal pattern as a electrical wave from electrolysis resources process. The percentage of inherent moisture
content is being different for each coal ratio caused by electron suppy from electrolysis process.
8
Inherent Moisture (% adb)
7
6
5
4
3
Rasio Batubara : Kerosin = 1 : 10
Rasio Batubara : Kerosin = 1 : 20
Rasio Batubara : Kerosin = 1 : 40
2
0
2
4
6
8
10
12
14
Voltase (Volt)
Fig 1.2. Electrolyse variable (voltage) to decreasing inherent moisture
content (%adb) Process temperature 50 oC
Yogyakarta-Indonesia, 4-5th December 2007
Chemical Engineering Department , Gadjah Mada University
14TH REGIONAL SYMPOSIUM ON CHEMICAL ENGINEERING 2007
ISBN 978-979-16978-0-4
IV. CONCLUSIONS
Electrolysis give significant effect to the decreasing of inherent moisture content and increasing of coal heating
value . The highest decreasing of inherent moisture content is at coal-kerosene ratio 1: 20, temperature 70 oC
and voltage 12 volts with percentage of decreasing achieved 78.16%.
REFERENCES
[1] Almu’minin Syarif, 2005, “Pengaruh Thermal Dewatering Batubara terhadap Kualitas Batubara”,
Laporan Tugas Akhir Jurusan Teknik Pertambangan Fakultas Teknik Universitas Sriwijaya, Inderalaya.
[2] Evans D.G.; and Seimon S.R. 1979. US patent number 3.552.031
[3] Syarifudin and Rr. Herminuke E.H, 2004 “Quality Improvement of Musi Bayuasin Low Rank Coal with
Deriving Inherent Moisture In Upgraded Brown Coal Process” Proceding of HEDS Seminar on Science &
Tecnology, Jakarta.
[4] Chaffe dan I Yarovshy, 2005, “The Chemistry of Coal-Water Interactions: and Theoritical and Experimentl
Investigation”, CRC for Clean Power from Lignit, Monash University dan RMIT University, Melbourne.
[5] T. Deguchi, T. Shigehisa and K. Shimasaki, 1999, “Study on Upgrading Brown Coal Process for
Indonesian Low Rank Coal”, Kobe Steel, Ltd., Procedings of 10th ICCS, Jepang.
[6] Meyers, Robert. A, 1981, “Coal Handbook”, Marcell Dekker. Inc, New York.
[7] Berkowitz. N, 1985, “The Chemistry of Coal: Coal Science and Technology”, Volume 2, Elvessier
Publicatin.Co, Amsterdam.
[8] Bahrin, D.; and Bustan, M.D. 2006. Thesis: The Study Of Effects Of Electrolysis Variables To The Inherent
Moisture Content In Brown Coal. Palembang: University of Sriwijaya.
Yogyakarta-Indonesia, 4-5th December 2007
Chemical Engineering Department , Gadjah Mada University