Sustainable Energy in Asia -2025 by Low Rank Coal up-gradation in Indonesia

-Sanjay Singh

INTRODUCTION:

Energy is a basic requirement for development of any country as well as

people’s quality of life. There are enough resources available around the world

to meet the energy demand but the main challenge is to how to get these

resources techno economically feasible to manage the energy demand with

environment challenges.

For developing country, it is beneficial that developed country transfer

technology and expertise freely without any barrier to reach the balance gap

for R & D efforts as required for techno-economic utilisation of resources.

Indonesia have 61.3billion ton of Coal resources with 19.3 billion ton as Coal

reserve and can play a vital role in the energy mix design module for key

energy consuming market of China, India, Japan & Korea.

Around 70% 0f Indonesian Coal are claimed as Low Rank Coal because of High

moisture content ( 35-50%) and GCV less than 5000 Kcal/kg but having less Ash

% and few slots are defined as High sulphur blocks having TS 3-4% but overall

average TS < 0.5 % . For commercial purpose, GOI treat Lignite to Sub

bituminous C rank Coal having Moisture > 35% with low Calorific Value ( <5100

Kcal/kg ADB) as Low Rank Coal.

The Rank wise coal distribution in Indonesia area as:

Sub Bituminous, 27%

Lignite, 58%

Bituminous, 14.5%

Anthracite , 0.5%

LOW RANK COAL-

The principal feature in Conversion of Vegetable debris to Peat-Lignite-Sub

Bituminous Coal- Bituminous Coal- Anthracite Coal i.e Coal Ranking up-

gradation is also rapid de-watering because of natural chemical

decomposition, and increase in pressure, temperature as a result tectonic

activity and overburden volume within compacted mass of matters.

Inherent moisture is inside the Coaly matter and mineral matter that is

included in the Coal, In addition of above inherent moisture, Coal is known to

absorb water when exposed in humid atmosphere during mining, stacking,

transportation in open wagon or washing.

In low rank Coal fuel like Sub bituminous and Lignite, the separation of Surface

and Inherent moisture is difficult to do because of high porosity characteristics

and sponge like nature of these materials as compare to Bituminous and

Anthracite Coal.

There are number of negative aspect associated with the use of high moisture

Coal as termed Low rank..

Low thermal efficiency ( More Coal being used for per unit energy

generation)

Low stripping ratio work to maintain Mining Cost (Poor recovery of Coal

resources as not feasible to do mining on high SR with respect to Sale

price of Low rank Coal)

High transportation cost per unit energy content.

High tendency for spontaneous Combustion

High emission of Co2 & noxious gases per unit of energy generated.

Major factor for Low thermal efficiency of Coal is High moisture and its impact

on Heating Value is conceptualised with following basics to know impact on

heating values.

MOISTURE % VS HEATING VALUE:

Coal is a composition of Total Moisture, Fixed Carbon, Volatile matter and Ash

content that can be analysed by Proximate Analysis of Coal as:

TM- 19.3%, IM-11.5%,Ash- 2 % ARB, Volatile Matter- VM- 40.1% ARB,

Fixed Carbon (FC) - 38.6% ARB, GVV (Kcal/Kg) - 5766 ARB, 6419 ADB

The heating Value of Coal is mainly generated because of Fixed Carbon

and Volatile Matter parameters only in the Coal and other parameter as

like Moisture, Ash don’t contribute any heating Value in the Coal.

Volatile Matter of all Coal is different based on composition of H2, N2,

O2 and other gases.

Heating Value from Fixed Carbon + Heating Value from VM = Heating

Value of Coal

Latent heat of Carbon – 32.8MJ/Kg (7.84 Kcal/gm)

Heat Value generated because of Fixed Carbon in 1 Kg Coal-386*7.84 =

3026.2 Kcal/Kg of Coal

Heating Value of VM in 1 kg Coal sample = 5766-3026.2 = 2739.8 Kcal

401 * Lvm = 2739.8 Kcal

Heat Value from VM for particular Coal sample – 6.83 Kcal/gm

Impact of 1% moisture reduction on Heating Value:

TM+ FC + VM+ ASH = COAL

19.3gm + 38.6gm + 40.1gm + 2gm = 100gm Coal

18.3gm + 38.6gm + 40.1gm + 2gm = 99gm Coal (1 % M Reduction)

18.3 gm +(38.6+ 1*38.6/80.7)gm+ (40.1+1*40.1/80.7)+(2+1*2/80.7) =

100gm Coal ( Rationalisation)

18.3gm + 39.08gm + 40.6gm + 2.02gm = 100gm Coal

183gm+390.8gm+406gm+202gm = 1000gm Coal

% increase in Fixed Carbon content b’cs of 1% Moisture reduction-

0.48%

% increase in Fixed Carbon content b’cs of 1% Moisture reduction- 0.5%

% increase in Ash content b’cs of 1% Moisture reduction- 0.02%

Heat Value increase in Coal b’cs of 0.48% increase in Fixed Carbon –

4.8*7.84= 37.63 Kcal

Heat Value increase in Coal b’cs of 0.5% increase in VM – 5*6.83= 34.15

Kcal

Heat Value increase in Coal b’cs of 1% decrease in TM –

7.63+34.15=71.7 Kcal.

The other adding factor in Heating Value is Sulphur Content that is not

included in the basic calculation to find out the impact of Moisture on Energy

content of the Coal.

LRC RESERVE WRT SALE PRICE:

Mining of LRC and its export is feasible for Mine location near to Sea Port

facilitating the logistics and transportation Cost with Thick seam as its reserve

become limited because of working on less stripping ration up to 1:3.

LRC minable reserve get reduced around 3-4 times as compare to High grade

Coal Minable reserve for same geological situation because of less FOB price

as around 2.5 time leading to no investment in LRC mining even because of

vast reserve availability.

Under utilisation of minable reserve for LRC by Mining at Stripping ratio < 1:3

recommend Coal upgardation technology for Sustainable energy balance in

Indonesia and surrounding Asian country..

INODESAIN COAL PRICE INDEX:

There is difference in price of around 52 USD for 28% Moisture

equivalent to 1.85USD/1% moisture. For Coal having high moisture %

and less GCV the price index is less as compare to less Moisture % for

per unit of heat value at FOB. But the Cost of transportation remain

6500 GAR/6200NAR/12%

TM

5800 GAR/5500NAR/18%

TM

5000 GAR/4700NAR/30%

TM

4200 GAR/3900NAR/40%

TM

89.74

72.3558.74

38.04

KALIMANTAN,INDONESIA (FOB) PER TONNERef:Issue 105,15th April 2010( Argus Coal Indo)

same for all rank of Coal and that leads to disadvantage for low rank

Coal for its utilisation close to Mining Site.

Transport Cost impact on the Coal is not being considered but with same cost

for all type of Coal it is preferred to purchase only high grade Coal..

LOW RANK COAL UP-GRADATION & UTILITATION:

Due to limited Coal reserve of High grade Coal it is mandatory to upgrade the

Coal quality of Low Rank Coal by various available techno economical process

under R & D, Coal either used directly in form of Solid or converted into gas or

liquid that is cleaner to environment and much easier to be handled in

transportation & utilization.

6500 GAR/6200NAR/12%

TM(A)

5800 GAR/5500NAR/18%

TM(B)

5000 GAR/4700NAR/30%

TM©

4200 GAR/3900NAR/40%

TM(D)

1.3811.247 1.175

0.906

Kalimantan Coal Grade- FOB price ( Cents/Kcal)

LRC

Coal Gassification

Coal Briquetting

Power Generation

Coal liquification

By LRC up- gradation by above technology, the abundant reserve of LRC can be

used both for domestic use and export market.

- LRC should be upgraded to clean and high calorific energy sources

before used or transportation for longer distance.

- LRC should be utilised for power generation that must be close to Mine

Site..

- LRC is converted into gas by Coal gasification.

- LRC is converted into Oil by Coal liquefaction.

- LRC is converted in Briquettes after moisture reduction without binders.

With this price variance of around 52 USD per ton for Coal having difference in

Moisture % by 28% it look techno-economic feasible to upgrade Coal by

various technology as mentioned.

COAL BRIQUETTING:

In the Coal briquetting process the Low rank Coal is crushed to -8mm and dried

in rotary steam tube dryer from 60 % to about 15%, the dry coal is then cool

and briquetted without a binder, using a extrusion press at 1200 kg/cm2 to

form hard compact Coal.

89.7472.35

58.74

38.0438.04 38.04 38.04 38.0451.7

34.3120.7

0

6500 GAR/6200NAR/12% TM

5800 GAR/5500NAR/18% TM

5000 GAR/4700NAR/30% TM

4200 GAR/3900NAR/40% TM

KALIMANTAN,INDONESIA-PRICE INDEX VARIANCE WRT 40% TM COALRef:Issue 105,15th April 2010( Argus Coal Indo

White Energy Company Limited 51% owned subsidy, PT. Kaltim SupaCoal has

build a 1MTPA binder less Coal briquetting plant in Indonesia in joint operation

with PT.Bayan Resources. WEC technology upgraded low grade High moisture

Coal by removing the moisture from Coal, thereby significantly increasing heat

energy content and quality. The planted process involve the crushing, drying

and briquetting of high moisture Coal resulting in converting the product into

higher energy content, stable product, while maintaining low sulphur ,low ash.

The resultant upgraded coal is of export quality and planned to export price

when sold by PT. Kaltim Supa coal. The Company has also JV agreement with

Adaro group to build additional plants in Indonesia.

Main factor that has to be review for this technology is the better transport

facility and storage facility if Briquette absorbs water from humid

environment; rain etc during transport and storage.

Physical and chemical characteristics of Coal briquettes after its exposure with

Rain and its impact on Increase in moisture % during storage and transport, its

impact of increased moisture on stability of Coal Ignition time, combustion

characteristics wrt of ellipse shaped, cylindrical briquettes should be

investigated otherwise the its export without considering good transport

facility and storage system will remain an issue..It is well known that increase

moisture leads to decrease in compressive strength, and combustibility..

COAL GASSIFICATION:

Gasification is conversion of Coal into gaseous product (CO & H2) either with

or without reactant (Air, Oxygen, steam or mixture of these) CO & H2 can be

converted into CH4.

Coal + Air (O2 & N2) --- CO + H2+ N2 (Producer gas , Low gas < 200

Btu/ft3)

Coal + Air (O2 & N2) + Steam (H20) --- CO + H2+ N2 (Water gas, Low gas

< 200 Btu/ft3)

Coal + Oxygen (O2) + Steam (H20) --- CO + H2 (Synthesis Gas/Syngas, Gas

- 200-400 Btu/ft3)

CH4 (Synthetic natural Gas, Gas - 1000 Btu/ft3)

For gasification agent as Steam only content of Hydrogen gas is more and

Carbon monoxide is less as compare to gasification agent as Oxygen & Steam

Mixture and Oxygen only.

GOI has planned to replace use of natural gas from LRC gasification in

petrochemical industry as as gas fuel in other industry as like fertiliser plant

etc. The gasification process of LRC can also produce Methanol, of of the fuel

source for transportation in the future.

Study shows that LRC with cut-off price of Natural gas is at of USD2/MMBTU

with LRC price of USD 30/MT and when the level price of gases increases then

using this technology will become feasible as Integrated Gasification Combine

Cycle (IGCC).

Around 5000 MW of energy are being generated by this technology mainly in

USA, Germany& Italy. Integrated drying gasification Combined Cycle( IDGCC)

offers substantial improvements in fuel efficiency and Cost saving for High

moisture Low rank Coal.

While this technology looks to be meet the future energy requirement may be

2025-2050 because of limited reserve of high grade Coal and advantage of this

process technology in term of clean environment as compare to conventional

power plants..

- Pre combustion cleans up of fuel prior to power generation.

- Best suited technology for High Moisture & High sulphur Coal as sulphur

can be recovered in between process.

- Generate less solid waste as compare to conventional power plant.

- Use 20-50% less water and can be utilised dry cooling to minimise water

consumption.

- Have option of C02 disposal by geological sequestration and less

emission of pollutant as like Nox, Sox etc..

At present this technology have high Capital & operating cost as compare to

conventional power generation and can only be make economical only after

imposing taxes of environment pollutant or R & D effort further to make it

economical and established technology.

Coal

Gasification

Synthetc gas

Methanol

Ethylene/Proylene Acetic Acid

Fischer-Tropsh Liquid

Jet Fuel Waxes FT Diesel Naptha

H2/Ammonia & Urea/Transport

Fuel/Town gas Iron Reduction Power & Steam

COAL LIQUEFECTAION:

Coal liquefaction can be divided into two process i.e Direct and Indirect

Coal Liquefaction, the indirect Coal liquefaction the production of

hydrocarbon is from synthesis gas consisting of Carbon monoxide and

Hydrogen. This gas is cleaned of all impurities and the clean synthesis

gas is sent to Fisher-Tropsch reactor where most of clean gas is

catalytically converted into zero sulphur liquid hydrocarbon fuels. Its full

scale plant is made in South Africa while it is expensive in term of

thermal efficiency, moreover the other by-product can also be

generated after few reaction and catalyst that may put some advantage

in this technology.

In direct Liquefaction, High molecular structured Coal is reacted under

high temperature and pressure with hydrogen and Coal derived solvent

with catalyst to produce a synthetic Crude oil, the same oil then further

upgraded with distillation and another hydro cracking to produce Light

and Medium Oil as described in flow chart..The thermal efficiency vary

from 50-70% based on Coal grade etc..

Study shows that oil recovered from 1 ton of Coal is 3 barrel for

Indonesian South Banko Coal having 35 % moisture and 1 barrel Oil for

Victorian Coal having 60% moisture.

Few study mentioned that cost of production of Oil from Coal is around

USD 50 per barrel and in today contest with Crude Oil Cost in range of

USD 82/ barrel (Nov.2010), it look economical to prospect further for

Conversion of Low rank Coal into Oil to meet the requirement of

transport fuel in near future with fast depletion of Natural Oil and gas

sources.

LRC POWER PLANT:

Conventional technology for thermal power generation from Low Rank

Coal having high moisture involve pulverised Coal combustion & Coal is

dried on line in an integrated drying system. For this large proportion of

hot flue gas is recycled to dry the Coal, LRC furnaces have bigger size 1.5

times in height and 1.4 time in area to meet the same power generation

because of large volume handling as compare to Bituminous Coal result

in high capital cost, beside this significant improvement has been done

to improve the Coal efficiency and green house gas emission but still

power plant is recommended near Mine Site.

CONCLUSIONS:

In Asia shortfall of Oil and Natural Gases is expected to grow in future

with present fuel-energy matrix. Present developing Asian economics

and growing requirement of fuel for transportation & energy per captia

requirement in Asia facilitate LRC up gradation and Indonesia will play a

major role to maintain a Energy Balance in Asia.\

With current price variance of 52 USD/MT @ FOB Kalimantan data in

between Coal of grade having difference of 28% moisture recommend

bright future of Coal briquetting with certain improvements in transport

and storage improvement to meet at export level specification.

The future requirement of Oil and gases mainly for transportation

requirement in Asia and high price of Oil as USD 82/barrel and positive

result on Coal liquefaction at level of 3 barrel per ton of LRC for

Indonesian Coal shows future of Indonesia’s Low Rank Coal for Sustain

Energy balance in Asia.

REFRENCES:

1. Geoffy Kimber, Petrol & Diesel from Coal, British Coal liquefaction

process, CAER & IMMR –Research paper

2. Sadao Wasaka” Bulletin of Japan Institute of Energy”

3. Development of Coal liquefaction technology- Nippon Coal & Oil Ltd.

4. Report of the result of International Coal Liquefaction Cooperation

project, Development of Low grade Coal liquefaction technology 2003.

5. Upgraded brown Coal process development Kobe steel Engineering &

Japan Coal Energy Centre Report,2003

6. Indonesian Coal development, Ministry of Energy and Mineral

Resources, 2007.

7. Douglas W. Later, Determination of hydrogen donating property of Coal

liquefaction process solvent, Pacific NW Lab, Washignton.

8. John Winslow, Direct Coal liquefaction technology, US department of

energy.

9. Hartiniati, Prospect of Coal liquefaction in Indonesia, BPPT Technology.

10. David & Brain, Utilisation of Low Rank Coal, Envirosafe Pty Ltd, Austraila.

11. White Energy Coal bulletin on Coal briquetting.

12. IGCC workshop India 2008, US department of Energy.