Download european gas imports: ghg emission from supply chain

EUROPEAN GAS IMPORTS: GHG EMISSIONS FROM THE SUPPLY CHAIN
Antonio Taglia, Manager Consultant Altran Italia, (39) 348 8004912, [email protected]
Nicola Rossi, Technical Consultant Altran Italia, (39) 333 7555274, [email protected]
Overview
Natural gas imports to Europe will increase with a constant annual rate of 4,5% due to both the reduction of internal production
and the constant increase in gas demand. As a consequence the total gas to be imported to Europe in 2025 will be around 600
bcm, doubling the current value. This element, supported by the supply diversification that European Union is pursuing, is
pushing towards the construction of new regasification terminals leading to an increase of possible gas suppliers. Gas can be
imported into Europe in two ways: through pipeline in gaseous form or it can be liquefied, transported in vessels and finally
regassified in Europe. These chains differ not only from the physical point of view, but also from the environmental and
economical point of view. However, in order to transport the gas from the production fields to Europe, some energy is required
and its overall amount differs according to the way and the path the gas is imported.
The aim of the paper is to analyse from the environmental and economical point of view the global impact of the gas that enters
into Europe, investigating the contribution of all the chain steps, starting from the production of the gas until the consumption
in a “combined cycle gas turbine” (CCGT) plant for power generation. Six different cases are studied: three are about a
pipeline-based transport and three about LNG production, transport through tankers and regasification.
These six cases are compared to the GHG emissions of a reference case: power generated in a CCGT plant in North Africa and
imported to Europe.
Methods
The six case studied are:
1. Case A1: gas production in the Yamburg and Urengoy fields (Russia), transport through Central and Northern Corridor
pipelines and consumption in Germany
2. Case A2: gas production in Bahr Essalam field (Libya), transport through Greenstream pipeline and consumption in Italy
3. Case A3: gas production in Krechba, Teg and Reg fields (Algeria), transport through MEG pipeline and consumption in
Spain
4. Case B1: gas production in West Delta Deep Marine concession (Egypt), liquefaction in Segas LNG plant (Egypt),
regasification in Panigaglia and consumption in Italy
5. Case B2: gas production in North field (Qatar), liquefaction in Qatargas LNG plant 2, regasification in Adriatic LNG plant
and consumption in Italy
6. Case B3: gas production in Dolphin field (Trinidad and Tobago), liquefaction in Atlantic LNG plant (Trinidad),
regasification in Bahia de Bizkaia (Bilbao) and consumption in Spain
The study encopasses five steps:
1. Definition of the main current and future European gas suppliers. This activity deals with: analysis of the current gas/LNG
flows, analysis of the supply contracts, development of new import and export infrastructures.
2. Set up of six different scenarios of supply, on the base of the analysis of the step 1. Three cases are based on pipeline
transport and three on LNG production, transport through vessels and regasification, as presented in the figure 1.
3. GHG’s emissions analysis of the six different gas chains, considering for each part of the chain: fuel consumption (and
resulting CO2 emissions), natural gas venting from leakages, CO2 venting (e.g. for natural gas sweetening in the
extraction and treatment facilities). This data are calculated by taking into account: efficiency of technologies in the
different chain steps, site specific characteristics of the production fields (e.g. CO2 content in the raw gas), transport
distance and type of gas chain (LNG or pipeline).[3]
4. Analysis of the results and comparison of the six scenarios from the environmental point of view (energy consumption,
GHG emissions).
5. The same analysis is carried out from the economical point of view.
NG venting
NG flaring
Production
Energy
CO2 venting NG flaring
Pipeline
transmission
NG flaring
Processing
Energy
NG
Liquefaction
Energy
UPSTREAM
Figure 1 – Gas supply chain scheme
Energy
Tanker
transport
Energy
MIDSTREAM
Energy
NG flaring
LNG
regasification
Distribution &
Storage
Energy
Energy
DOWNSTREAM
Combustion
Results
GHG emission - kg/Mbtu
The GHG emissions for the six gas chains, analysed in this study, are presented in the graph below (figure 2). Our results show
a different environmental impact as to the different chains. The average value of the chain emissions is around 15
kgCO2eq/Mbtu of natural gas imported, but the overall emissions could be up to 22 kgCO2eq/Mbtu (+50%) in the LNG chain
B1. Considering that the CO2 emissions from the combustion of the natural gas is around 54 kgCO 2eq/Mbtu, the emissions of
the supply chain increase the overall emissions by 30%.
The economical comparison of the six different gas chains will be presented in the same way.
60,0
Pipeline import
Lng import
NG combustion
50,0
40,0
30,0
20,0
10,0
0,0
A1
A2
Production
Tanker transport
Storage / Distribution
A3
B1
Treatment
LNG regasification
B2
B3
NG Liquefaction
Pipeline transmission
Figure 2 – GHG emissions comparison for the six supply chain cases [1][2][4].
Conclusions
Environmental impact of energy production from gas has to be fully evaluated analyzing also the impact of the supply chains: it
can reach the 40% of the CO2 emissions from gas combustion, indeed. From a preliminary analysis of the results, we highlight
that several factors strongly affect the GHG emissions of the gas supply chain:
 The efficiency of the liquefaction and regasification process: different technologies show widespread values of
thermal efficiencies.
 The efficiency of the midstream step of the chain: performance of the LNG tanker engine (older/newer technology,
motor size, fuel used) and performance of pipelines (older/newer technology of compression, natural gas leakages).
 CO2 concentration in the raw gas (fields can have a CO2 content up to 14%mol compared to a worldwide average of
2%mol)
 The amount of gas flared in the production fields.
With regard to the economical comparison, the greatest contribution to the gas price comes from the upstream process (around
60%). As to this issue, our research shows widespread results in different countries due to mainly reservoir and fields
characteristics, and due to different fiscal regulation.
In conclusion, this analysis allows to have an outlook of the economical and environmental impact of the different supply
chains for gas import to Europe. Till now the decisions about the supply have been based on economical or political factors,
neglecting the environmental impact. However, Europe, which aims to cut GHG emissions, should consider also the supply
chain emissions, given that a remarkable reduction of overall emissions would be feasible (a decrease of 15% in the 2025 gas
supply chain emissions would cut around 55 Mton CO2, 1% of the total European 2005 CO2 emissions [5]).
References
[1] P. Jaramillo, W. Michael Griffin, H. Scott Matthews, Comparative Life-Cycle Air Emissionss of Coal, Domestic Natural
Gas, LNG, and SNG for Electricity Generation. Environmental Science Technology, 2007, 41 (17), 6290-6296.
[2] P.J. Meier and G.L. Kulcinski, Life-Cycle Energy Cost and Greenhouse Gas Emissionss for Gas Turbine Power, Research
Report, 2001.
[3] IPCC, Carbon Dioxide Capture and Storage, 2005.
[4] I. Tamura, T. Tanaka, T. Kagajo, S. Kuwabara; T. Yoshioka, T. Nagata, K. Kurahashi, H. Ishitani, Life cycle CO2
analysis of LNG and city gas. Applied Energy, 2001, 68, 301-319.
[5] European Energy Agency Data, http://www.eea.europa.eu, 2009.