INDIAN DOMESTIC COAL
TRANSPORT LOGISITCS AND TECHNOLOGY
by
Sid Sridhar
Seabulk Systems Inc.
Richmond, British Columbia, Canada
&
S. K. Grover
Geological Coal Resources – India (as on 31.3.2012)
1
Existing Domestic Coal Transport: Obstacles
Conveying overland a practical solution for power plants
adjacent to the coalfield, say distances on the order of about
50 km. MGR ideal for handling 5 million tes/an & above.
Trucking requires road upgrades and vehicle fleets and could
be a transport solution for distances up to 200 km, but is
likely inefficient & costly for longer haul transport. Also a
pollution hazard.
Railways require upgrade including new trackage and rolling
stock and supporting infrastructure and would be a transport
solution for distances up to 2000 km.
Railway gearing up to meet the challenge.
2
Test Case For Transport Logistics
• Ideal case study – North Karanpura Coalfield (NK)
• Expected Coal Resource over 12.5 billion tes
• Production Capabilities > 250 million tes/an
• Need for Multi-modal Transport Logistic such as
Conveyor/Road/MGR/Rail may still be a challenge for Coal
evacuation from NK
• Innovative Solution – Slurry Pipeline Transport
a) For Plants 200 km or so with more than 5 million tes/an
requirement
b) For Plants > 200 km with Higher tonnage over longer
distance – supplement Indian Railway System specially
on Dedicated Freight Corridor (DFC). At an appropriate
location 30 to 40 million tes/an of coal may be loaded in
DFC. We can have such concepts on DFC in future
from this & other coalfields like IB, Talcher, Mand
Raigarh, Hasdeo etc.
3
Alternative Coal Transport: Slurry Pipelines
In consideration of the noted transportation obstacles , slurry
pipelines are proposed as an alternative/supplement approach
for Indian domestic coal transport. Slurry pipeline systems
have some distinct advantages over existing transport
infrastructures, including:
• Practical for long haul distances of 200 km or longer
• Secure enclosed transport isolated from the environment
• Extensive technology exists to create slurry pipeline
systems
• Water can be recycled
• Integrates coal beneficiation such as marginal ash
reduction specially clay
• Spontaneous combustion risks mitigated
• Storage typically in tanks
• Dewatered coal may be briquetted enabling trans-loading
4
by rail
Slurry Pipeline Systems
Slurry pipelines convey many commodities world wide including coal.
5
Coal : Slurry Pipeline Process
Process integration at certain stages of coal transportation
improves overall delivery economics by enabling:
 reduction of ash and impurities at the mine
 pumping a fine coal slurry through an overland pipeline
 coal storage in slurry tanks at the power plant or transload after briquetting
 dewatering by centrifuge and hyperbaric filters yields
over 99% recovery of coal from the slurry
Steam atmosphere drying and briquetting can enable rehandling as a dry bulk commodity. Briquettes are stable and
not susceptible to spontaneous combustion.
Water is recyclable within the system and is not discharged
to the environment.
6
Coal Slurry Production: Sizing
Coal sizing, cage impaction
example shown.
7
2 mm minus crushed coal
sample.
Coal Slurry Production: Ash Reduction
Cyclones are an example of
technology that may be used
to separate clay from fine
coal.
8
Pipeline Terminus: Slurry Storage
Tank storage of slurry coal depicted at a thermal power plant
Highlights:
 hydraulic reclaim avoids the need for tank agitation
 tank storage is more contained than open stockpiles
 rain and wind dispersion of the product is avoided
 slurry storage avoids spontaneous combustion risk
9
Dewatering and Drying: Coal Moisture
Coal moisture and conventional dewatering and drying of fine
coal.
10
Coal Briquetting: Rationale
1. Dried hot filter cake is at risk of spontaneous combustion
if stored for long but this can usually be avoided by
briquetting which stabilizes the agglomeration.
2. The agglomeration of fine coal filter cake into briquettes
enables it to be handled and transported as a dry bulk
material by conventional means or dried coal is not fed
immediately.
3. Briquettes are compacted at high pressure and therefore
potentially denser than loose fine coal, this makes for
more efficient transportation.
4. Briquettes mitigate the creation and propagation of coal
dust.
11
Coal Briquetting: Binders
Objective - Binderless Briquetting:
1.Binderless briquetting avoids the cost of expensive binders.
2.Important variabl13es for binderless briquetting of coal are:
 Moisture content
 Temperature
 Compaction pressure
 Particle size distribution
 Coal properties
3.The system proposed herein pushes the moisture content,
temperature and compaction pressure variables all in a
direction favourable for briquette production.
12
Coal Briquetting: Variables
Variables Influencing Binderless Briquetting:
1. Moisture Content: Surface moisture and some inherent
moisture is vaporized from the fine coal as it passes
through the steam atmosphere of the fluidized bed drier.
2. Temperature: Steam atmosphere drying occurs above the
boiling point of water, typically at about 120° C, so the fine
coal is rapidly heated. The dried fine coal is briquetted
before it cools significantly so compaction takes place at
an elevated temperature.
3. Compaction Pressure: Pressure is high and maintained
by roll compaction briquetting presses specially designed
for hot product.
13
Coal Briquetting: Variables
Particle Size Distribution:
1. The PSD that is optimal for conveyance of coal by
slurry may not be exactly the same as the PSD that is
optimal for briquette production.
2. PSD at 2 mm minus for coal slurry enables the
material to be easily suspended in turbulent pipeline
flow. Briquetting specialists estimate that this PSD is
a possible for
binderless briquette production,
however, testing would be required to confirm.
14
Coal Briquetting: Production
Double Roll Press Briquette Machine
(Koppern Photo)
A number of firms specialize in coal briquette production and have roll
compaction presses designed for the purpose.
15
Coal Briquetting: Quality
Quality Factors:
1. Briquettes are typically pillow shaped and the size
can be specified. Typical dimensions are 40 mm
square pillow briquettes.
2. A multitude of tests are available to assess the
robustness of briquettes for
handling
as a
conventional dry bulk material.
3. Briquettes should avoid breakage during handling
and storage and resist absorption of moisture.
16
Why Slurry Pipelines?
1. Economics
Slurry pipelines have attractive economics for longer
haul distances and large tonnage.
2. Scalability
Slurry pipeline systems can be scaled with single
pipes handling about 10 Mtpa of commodity.
3. Implementable
The technology required to implement slurry pipeline
systems exists and is with well established
companies and with proven installations worldwide.
17
Why Slurry Pipelines?
4.
Beneficiation
The use of slurry systems and the use of fine coal
integrates with existing beneficiation technologies.
5. High Recovery
The system utilizes fine coal which means more coal
recovery from the mine.
6. Ash Mitigation
Ash is marginally reduced at the mine.
7. Isolation From the Environment
The slurry system is fully enclosed from the environment,
securely buried beneath the overland transport route and
process water is recycled within the system without
discharge to the environment.
18
Why Slurry Pipelines?
8. Spontaneous
Combustion Mitigation
Transport of coal as slurry and production of coal
briquettes
after
drying
avoids
spontaneous
combustion risk.
9. Power Plant Feed
Dewatered and dried slurry filter cake can also be fed
directly into the power plant.
10. Trans-loadable Commodity
Briquettes are a stable beneficiated dry bulk fuel that
can be trans-loaded by rail for example.
19
Example Transport System: Costs and Financial
1. Key
assumptions:
• Annual transport of 6 Mtpa briquettes at 25% TM
• Coal sizing and scrubbing at the mine
• Overland transport by 220 km long slurry pipeline
• Positive displacement pumping
• Coal slurry at 48% weight concentration
• Slurry and return water pipe diameter 610 mm
• Storage, reclaim, dewatering, drying, briquetting,
stockpiling
2. Static financial calculation and cost assumptions:
• Costs million $USD
• Interest rate 7%
• Period 25 years
• Fixed Asset IRR 12%
• Depreciating Asset IRR 20%
• All estimates are exclusive of import duties, brokerage or
taxes
20
Example Slurry System: Costs and Financial
Subsystem Description
Coal Sizing and Slurry Production
Coal Scrubbing
Mine Water System
PD Pump Station
Scrubbings Disposal
Pipeline Corridor Development
Slurry Pipe Supply & Install
Slurry Storage and Reclaim
Dewatering Plant
Drying Plant
Briquetting Plant *
Power & Control Systems *
Terminus Water System *
Birquette Stockpiling *
Stockpile Reclaim *
Integrated Total Costs
CAPEX
(M $USD)
OPEX
(M $USD)
Annual Cost
(M $USD/ yr)
Delivery Rate
($USD/tonne)
$14
$28
$3
$52
$1
$41
$93
$27
$22
$35
$81
$3
$2
$13
$12
$427
$5
$5
$1
$5
$0
$0
$2
$2
$3
$3
$5
$0
$0
$1
$5
$37
$6
$8
$1
$9
$0
$4
$10
$4
$5
$6
$12
$0
$1
$2
$6
$74
$1
$1
$0
$2
$0
$1
$2
$1
$1
$1
$2
$0
$0
$0
$1
$14
* to exclude when no briquetting
For plants about 200km away from coal source cost/te would be
about USD 9.79 i.e. Rs. 525 without briquetting etc. & with
briquetting the cost/te would be about USD 13.50 i.e. Rs. 725.
Longer the distance, higher the tonnage more cost effective since
terminal costs are high.
21
Implementation and Operation
The slurry pipeline proposal shown here has multiple
systems to implement and operate, these include:
1.
2.
3.
4.
5.
6.
Coal sizing, slurry production and scrubbing
Overland slurry pipeline
Coal slurry storage and reclaim
Coal slurry dewatering and drying
Coal filter cake briquetting
Briquette stockpiling and reclaim & loading into
Railway System
22
Implementation: Management
The scale and complexity of the type of integrated
transportation system proposed is fairly significant.
Successful implementation requires the management of a
design/ build contractor or a joint venture team comprised
of specialist firms in these key areas:
1. Coal preparation
2. Slurry pipeline
3. Dewatering and drying filter cakes upto 200/250
kms.
4. * Briquetting
5. * Materials handling and loading into railway wagons
* for various end users situated at long distance from Coal
Source
23
Implementation: Bankability
1. A novel approach
technologies.
that
integrates
existing
2. Major technology suppliers are qualified companies
with proven capability in their fields.
3. Studies and tests are required to refine the system
design and assess issues and risks.
4. A tonnage guarantee would be required.
5. Implementation under the control of a design-buildoperate contract for commodity transport from the
mine to end users would enable a ‘take or pay’
contract model to be implemented – totally bankable.
24
Implementation: Business Plan
1. Tonnage guarantee required to support financial plan.
2. Coal handled on a rate per tonne basis.
3. Take or pay form of contract if project implemented as a
single design-build-operate venture.
4. Operation subcontracted to regional firms.
25
Conclusions
Slurry pipelines used to transport Indian domestic coal:
1. Avoid the issues and bottlenecks existing transport
systems face
2. Have high utilization of mine output as it uses fine
coal
3. Transport a beneficiated coal product
4. Isolate the coal transport from the environment
5. Offer a competitive capital and operating cost in
comparison to the alternatives
6. Can be implementable as a design-build-operate
venture
7. Can be set up contractually to be bankable
8. Studies including coal testing is required to affirm
feasibility and economics
26
Thank you
Questions?