PSU-UNS International Conference on Engineering and
Environment - ICEE-2007, Phuket May10-11, 2007
Prince of Songkla University, Faculty of Engineering
Hat Yai, Songkhla, Thailand 90112
Economical analysis of Gas-to-liquid (GTL)
utilization in Thailand
Piya Srisuparangkul1, Navadol Laosiripojana1, and Suttichai Assabumrungrat2
1
2
The Joint Graduate School of Energy and Environment , King Mongkut’s University
of Technology Thonburi, Bangkok, Thailand
Center of Excellence on Catalysis and Catalytic Reaction Engineering, Department of Chemical
Engineering, Faculty of Engineering, Chulalongkorn University, Bangkok, Thailand
Abstract: Nowadays, the rate of the oil consumption of
vehicles in Thailand has been rapidly increasing due to
the expansion of industry sector. This rate results in the
large amount of released CO2 to the atmosphere, vast
quantity of imported oil and the energy security. One of
the solutions for these defects is to use natural gas as a
vehicle fuel (NGV: Natural Gas Vehicle). However, the
use of natural gas as transportation fuel is difficult in
terms of technical and economical. In term of technical,
natural gas must be compressed in high pressure heavy
storage, which makes it difficult to transport and use in
all vehicles. In term of economical, all current oil
stations must be changed to natural gas stations, which
costs a large investment cost.
Key Words: GTL, Economical analysis, Transportation
billion bahts for the import of crude oil as well as the
dramatic increase in the CO2 releasing to the atmosphere.
One of the solutions for these defects is to use natural gas
as alternative transportation fuel, as Thailand have their
own natural gas resource and this fuel is much cheaper
than crude oil. However, there are some limittation for
the use of natural gas in transportation section. For
instance, as the gaseous phase, natural gas must be
compressed properly in certain pressure. Moreover, the
new infrasturctures i.e. gas stations as well as the
modification of vehicle engine are required which costs a
large investment cost. The use of GTL (Gas-To-Liquid)
is an alternative method to overcome these barriers as
GTL is normally in liquid phase and the properties of
GTL are almost identical to diesel oil. GTL can be
produced by the converting of natural gas to synthesis
gas yia the reforming process, and further translating
synthesis gas to GTL via Fischer-Tropsch process. It has
been reported that GTL has greater quality and cleaner
than the conventional diesel. Furthermore, importantly,
this fuel can be used instead of diesel with the same
vehicle engines or blended with conventional diesel thus
it is not necessary to change in transportation methods
and gas station facilities. GTL can be derived form
syngas. In principle, synthesis gas (primarily consisting
of CO and H2) can be produced from any hydrocarbon
feedstock, including: natural gas, naphtha, residual oil,
petroleum coke, coal, and biomass. The lowest cost
routes for synthesis gas production, however, are based
on natural gas, the cheapest option being remote or
stranded reserves [1].
1. INTRODUCTION
2. LITERATURE REVIEW
Nowadays, the rate of the fuel consumption,
particularly diesel oil, in Thailand has been rapidly
increasing due to the expansion of industrial and
transportation sectors. This results in the loss of several
GTL (Gas-to-Liquid) is a refinery fuel, which
can be produced by the converting of natural gas or other
gaseous hydrocarbons into longer-chain hydrocarbons.
Methane-rich gases are converted into liquid fuels either
GTL (Gas-To-Liquid) is the method to
overcome those barriers because this solution changes
natural gas to liquid fuel via Fischer-Tropsch process.
The liquid fuel has a higher quality and burns more
cleanly than the conventional diesel. Furthermore,
fortunately, this fuel can be used instead of diesel with
the same vehicle engines, transportation methods and gas
station facilities. However, the capital investment of
GTL production plant has to be examined due to the
costly process. Therefore, in the present work, the
economical aspect of the GTL production in Thailand
was studied. From the study, It was found that with the
GTL plant capacity of 14,700 b/d or 5,365,500 b/yr, the
return period is approximately 3-4 years.
via direct conversion or via syngas as an intermediate
and then using the Fischer-Tropsch process. Through the
processes, the liquid-phase product can be used as fuel or
blended only with diesel fuel. The benefits of GTL
include:
Reducing emissions
Table 1 and Figure 1 show the comparison of
properties and emission releasing between GTL and
conventional diesel. It can be seen that GTL have much
lower sulphur compounds and it releases significantly
lower emission compared to the conventional diesel.
Table 1: GTL diesel characteristics [2]
Cetane number
Total Sulphur (wt%)
Total aromatics (Vol%)
Density (kg/l)
GTL diesel
> 70
< 0.0005
<3
0.78
Refinery Diesel
45-50
> 0.035
>10
0.82-0.86
technology chemically converts natural gas into cleanburning liquid products that can be easily shipped to
market. [4]
There are several steps to convert natural gas to
GTL. Firstly, natural gas containing mainly of methane
is reformed to synthesis gas. The first step is called
reforming process (steam reforming or partial oxidation).
The second step is called Fischer-Tropsch process, in
which reformulate hydrogen and carbon monoxide into
long-chain liquid phase hydrocarbons. As the last stage,
the liquid hydrocarbons are converted and fractionated
into products. Another product of the reaction is naphtha
that is high in paraffin content. Waxes derived from GTL
processes can be pure enough to use for food packaging
and cosmetics. The GTL processes in operation today
convert 10,000 cubic feet [286 m3] of gas into slightly
more than 1 barrel [0.16 m3] of liquid synthetic fuel.
Figure 2 The GTL synthesis chart
Figure 1 The GTL emission reduction [3]
Focusing on the possible production of GTL in
Thailand, Thailand has its own natural gas resource that
can be used as feedstock for GTL production. Table 3
presents the current Thailand’s Petroleum Reserve and
Production [5].
Reducing flared gas
It has been reported that Nigeria flared 620 bcf
(billion cubic feet) of natural gas in 2000. This is a key
factor in the Nigerian decision to pursue GTL has been
the attempt to reduce flaring. This is the benefit to not
only for Nigeria but for other countries as well.
Table 2 : Gas Flared in 2000 [4]
Region
Africa
Asia-Oceania
Europe
FSU
Latin America
Middle East
N.America
Flared NG (BCF)
1306
388
106
671
353
565
424
Alternative method to utilize natural gas
Until now, there are only two practical ways of
transporting natural gas: flow it through a pipeline in
gaseous form or chill and transport it as liquefied natural
gas (LNG). As another alternative method, gas-to-liquid
Table 3: Thailand’s Petroleum Reserve and Production
Petroleum Reserve
Natural Gas ( BCF)
LNG (million barrels)
Crude Oil (million barrels)
Petroleum Production
Crude
Oil
Equivalent
(Barrels/day)
Natural Gas (MMSCFD)
LNG (Barrels/day)
Crude Oil (Barrels/day)
LPG (Tons/day)
Sale Quantity and Price
Natural Gas
LNG
LPG
Crude Oil
Proved
10,743
261
192
At August 2006
607,960
2,343
76,790
129,465
297
Quantity
70.7 BCF
2.0 m barrels
8.2 m Kg
3.2 m barrels
Of the year 2005 (Updated May 2006)
Probable
Possible
11,598
9,555
293
158
119
76
2005
584,200
2,290
72,228
119,174
272
At July 2006
Price (Million Baht)
9,638
4,937
90
8,334
Recently, Thai government has supported the use of
natural gas or NGV for Thai transportation sector.
Regarding the current use of GTL in Thailand, Shell
Company had one transportation fuel product called
“Shell Pura Diesel” [6]. This Diesel is a semi-synthetic
diesel formulation that combines Shell regular diesel
with SMDS (Shell's Shell Middle Distillate Synthesis) processed natural gas and additives. SMDS process
converts natural gas into diesel, resulting in lower
emissions than conventional automotive gas oil. From
the case of Shell Pura, it means that there is a possibility
to use blended GTL diesel in Thailand. Nevertheless, the
proportion and quantity of the fuel must be investigated
further in a technical and economic analysis.
Currently, there are three current GTL operating
plants around the world, which are Mossel Bay in South
Africa, Bintulu in Malaysia, and Ras Laffan in Qatar.
Details of these plants are shown in Table 4, 5 and 6
Table 4 Plant locations, operator, and start-up
Name of plant
1 Sasol I
2 Sasol II and III
3 Mossgas
4 Shell Bintulu
5 Oryx GTL
Location
Sasolburg
South Africa
Secunda
South Africa
Mossel bay
South Africa
Bintulu
Malaysia
Operator
Sasol
Ras Laffan
Qatar
Sasol
Qatar QP
Start-Up
1955
Sasol
PetroSA
1980
1982
1992
Shell
1993
2006
Table 5 Reactor and feedstock of these plants
Name of plant
1 Sasol I
2 Sasol II and III
3 Mossgas
4 Shell Bintulu
5 Oryx GTL
Reactor
Both low and high FTS
tubular FB
Sasol advanced Synthol
CFB , FFB
High temp process
Fe catalyst, slurry bed
SMDS, Co catalyst
enhanced FTS
multi tubular FB
Sasol Low Temp
Slurry Bed Reactors
feedstock
Natural gas
Coal,Crude oil
Natural gas
Coal,Crude oil
Natural gas
Natural gas
Natural gas
Table 6 Plant capacity and cost
unit
25000 bpd
COST
Installation
27000-50000 $/bbl
2 Sasol II and III
34000 bpd
20000-25000 $/bbl
3 Mossgas
22,500 bpd
38,780 $/bbl
8 $/bbl
14700 bpd
(12500)
660 m$
9.6 $/bbl
34000 bpd
950 m$
4.5 $/bbl
Name of plant
1 Sasol I
4 Shell Bintulu
5 Oryx GTL
capacity
Operation
-
- GTL operating cost is 9.6 $/bbl
- Overall investment cost is 660 m$
- Capacity of 14,700 b/d or 5,365,500 b/yr
- Currency of 35.63 Baht/$
The cost comparison between the same amounts
at the capacity of Shell Bintulu plant of 14,700 bpd of
diesel consumed per day from conventional uses and the
investment and operating cost of GTL production.
According to the cost of diesel substitution, we used the
value of 14,700 bpd and converting to diesel price which
were deducted from the use of GTL instead. We also
used the diesel price of 23.34 Baht/Liter and converting
to the amount per year. From the investment cost of 660
m$ with operating cost of 9.6 $/bbl, the calculation of the
total cost of production per year was calculated.
3. RESULTS AND DISCUSSION
Based on the calculation, it was found that the
use of GTL will save the import of diesel oil for
approximately 19,912 million baths per year.
Nevertheless, in the first 2 year, Thailand must invest at
least 47,032 million baths for the installation of GTL
plant. Furthermore, 6,186 million baths per year must be
paid as the operating and maintenance costs. Tables 7
and 8 present the projection of total cost of GTL
production and saving cost (for diesel substitute) in
Thailand within 10 years of operation.
Table 7 The calculation for diesel substitutions
Yr Diesel Sub.(bbl) Saving cost(mB)
0
0
0
1
5,365,500
19,912
2
5,365,500
19,912
3
5,365,500
19,912
4
5,365,500
19,912
5
5,365,500
19,912
6
5,365,500
19,912
7
5,365,500
19,912
8
5,365,500
19,912
9
5,365,500
19,912
10
5,365,500
19,912
Cumu.Sav.Cost (mB)
0
19,912
39,823
59,735
79,647
99,558
119,470
139,382
159,294
179,205
199,117
-
3. METHODOLOGY
In the present work, the main data used are
based on the data from several resources as presented in
Tables 4-6. The important data applied in the present
work includes:
- The cost of diesel is 23.34 Baht per liter
- NGV price is 8.50 Baht/Kg or 5.1 Baht/L
(specificgravity 0.6 [7])
Table 8 The investment and operating cost of GTL
production
Yr
0
1
2
3
4
5
6
7
8
9
10
Oper.Cost (mB)
0
6,186
6,186
6,186
6,186
6,186
6,186
6,186
6,186
6,186
6,186
Inv Cost (mB)
23,516
23,516
0
0
0
0
0
0
0
0
0
Total cost of the yr (mB)
23,516
29,702
6,186
6,186
6,186
6,186
6,186
6,186
6,186
6,186
6,186
Cumulative cost(mB)
23,516
53,218
59,404
65,590
71,776
77,962
84,148
90,335
96,521
102,707
108,893
Figure 3 shows the comparison between the cost
of diesel saving and the total investment cost of GTL
plant (investment cost + operating cost + maintenance
cost), whereas Figure 4 shows the comparison between
the cost of diesel saving and the total investment cost of
GTL plant for each year. It can be seen that the curve of
diesel saving is lower than the curve of GTL investment
cost in the first 3 years. In the third year of operation, the
cost of diesel saving becomes higher than the cost of
GTL production, which means the return period of GTL
plant installation is 3-4 years. Nevertheless, it should be
noted that the return period also depends on several
parameters i.e. the plant capacity, and the costs of natural
gas and diesel. In addition, the composition and quality
of natural gas also play an important role of the return
period.
also depends on several other parameters i.e. the plant
capacity, the costs of natural gas and diesel, and
composition and quality of natural gas. Therefore, for the
future work, these parameters should also be taking into
account. Furthermore, the economical analysis for GTL
production and utilization for transportation section
should also be compared to other possible technologies
i.e. the use of Natural Gas Vehicle (NGV), the use of
Liquefied Natural Gas (LNG), the use of hybrid car, and
the use of hydrogen and fuel cells.
Cost comparison
6. ACKNOWNLEDGEMENTS
Cost (mB)
250,000
The financial support from the Joint Graduate
School of Energy and Environment (JGSEE) throughout
this project is gratefully acknowledged.
Saving cost of Diesel substi
Cost of GTL production
200,000
150,000
7. REFERENCES
100,000
50,000
0
1
2
3
4
5
6
7
8
9
10
Year
Figure 3 Comparison of the cost of diesel substitution
(saving) and the overall cost of GTL production for years
Cost comparison
Cost comparison
180,000
160,000
140,000
Total cost
120,000
100,000
Year 10
80,000
60,000
40,000
Year 1
20,000
0
0
50000
100000
150000
200000
250000
300000
350000
400000
450000
Cost of diesel substitution
Figure 4 Comparison of the saving cost and GTL
production.
5. COUCLUSION
From this study, it can be concluded that the use
of GTL, produced from Thailand natural gas, is one of
the good alternative method for diesel oil substitute in
transportation section. With the GTL plant capacity of
14,700 b/d or 5,365,500 b/yr, the return period is
approximately 3-4 years. Nevertheless, the return period
[1] P.L. Spath and D.C. Dayton , (2003) , “Preliminary
Screening Technical and Economic Assessment of
Synthesis Gas to Fuels and Chemicals with Emphasis
on the Potential for Biomass-Derived Syngas”,
NREL.
[2] Petroleum Economist , (June 2006), “New product
hits the road” Available online:
http://www.worldenergysource.com [Accessed on
21st August 2006]
[3] California Energy Commission, (2006), “Gas-toLiquid Fuels In Transportation”
http://www.energy.ca.gov/afvs/vehicle_fact_sheets/gt
l.html [Accessed on 27th August 2006]
[4] United States Association for Energy Economics
(USAEE), (2006), The Effect of GTL
Commercialization on Fuels and Specialty Products,
Dialogue, 14, 1, pp.7-16.
[5] Department of mineral fuels, (2006), “Petroleum
Production Report”
http://www.dmf.go.th/default_prev.asp [Accessed on
1st September 2006]
[6] Shell in Thailand (Shell Pura Diesel), (2006),
http://www.shell.com/home/Framework?
siteId=thailandth&FC2=/thailandth/html/iwgen/shell_for_motorist
s/fuels/zzz_lhn. html&FC3=/thailandth/html/iwgen/shell_for_motorists/fuels/pura_diesel
_1202 .html [Accessed on 31st July 2006]
[7] Unctad, (2006), Natural gas characteristics,
Available online:
http://www.unctad.org/infocomm/anglais/gas/chara
cteristics.htm [Accessed on 7th March 2007]