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Opportunities for low-cost CO2 storage demonstration projects in China
ARTICLE IN PRESS
Energy Policy 35 (2007) 2368–2378 www.elsevier.com/locate/enpol
Opportunities for low-cost CO2 storage demonstration projects in China Kyle C. Menga,,1, Robert H. Williamsb, Michael A. Celiaa a
Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, USA b Princeton Environmental Institute, Princeton University, Princeton, NJ, USA Received 20 March 2006; accepted 25 August 2006 Available online 27 October 2006
Abstract Several CO2 storage demonstration projects are needed in a variety of geological formations worldwide to prove the viability of CO2 capture and storage as a major option for climate change mitigation. China has several low-cost CO2 sources at sites that produce NH3 from coal via gasification. At these plants, CO2 generated in excess of the amount needed for other purposes (e.g., urea synthesis) is vented as a relatively pure stream. These CO2 sources would potentially be economically interesting candidates for storage demonstration projects if there are suitable storage sites nearby. In this study a survey was conducted to estimate CO2 availability at modern Chinese coal-fed ammonia plants. Results indicate that annual quantities of available, relatively pure CO2 per site range from 0.6 to 1.1 million tonnes. The CO2 source assessment was complemented by analysis of possible nearby opportunities for CO2 storage. CO2 sources were mapped in relation to China’s petroliferous sedimentary basins where prospective CO2 storage reservoirs possibly exist. Four promising pairs of sources and sinks were identified. Project costs for storage in deep saline aquifers were estimated for each pairing ranging from $15–21/t of CO2. Potential enhanced oil recovery and enhanced coal bed methane recovery opportunities near each prospective source were also considered. r 2006 Elsevier Ltd. All rights reserved. Keywords: Ammonia from coal; China; Carbon capture and storage
1. Introduction According to the International Energy Outlook 2005 (IEO2005), prepared by the Energy Information Administration of the US Department of Energy, China was the world’s second largest emitter of CO2 after the United States in 2002, contributing 13.6% of total world CO2 emissions or 3322 megatonnes (Mt) of CO2. In its Reference Case scenario, the IEO2005 projects that China’s CO2 emissions will grow 4.0% per year (the highest rate in the world), reaching 8133 Mt CO2 by 2025, at which point China’s share of world CO2 emissions is projected to reach 21%. By contrast, the IEO2005 projects that the US share of world CO2 emissions will decrease Corresponding author. Tel.: +1 212 616 1278.
E-mail addresses: [email protected] (K.C. Meng), [email protected] (R.H. Williams), [email protected] (M.A. Celia). 1 Now with Environmental Defense. 0301-4215/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.enpol.2006.08.016
from 24% to 21% during 2002–2025 and that in 2025, US emissions will be 98% of China’s (Figs. 1 and 2). This projected increase in China’s CO2 emissions is largely due to its rising energy demand. Between 2002 and 2025, China’s primary annual energy consumption is estimated to grow from 45.6 to 115.2 EJ, increasing its percentage of total world energy consumption in this period from 10% to 17%. Due to its abundant coal resources, the paucity of its oil and gas resources, and high world oil prices, China is expected to meet more than half of its incremental energy in this period with coal, the most carbon-intensive of the fossil fuels (IEO, 2005). Because of this heavy dependence on coal, it is likely that under a climate change mitigation policy, China will emphasize CO2 capture and storage for the coal-based part of its energy economy. Although CO2 capture is proven technologically, CO2 storage must be tested and analyzed in a variety of geological media through large-scale (1 Mt/year CO2 per project) demonstration projects before it can be
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Fig. 1. Historic and projected CO2 emissions by region. Source: US DOE, IEO2005.
Fig. 2. Percentage of world CO2 emissions by region. Source: US DOE, IEO2005.
implemented routinely with confidence as a major climate change mitigation strategy. Already storage demonstration projects of this scale have been underway since 1996 at the Sleipner Gas Field in the North Sea and since 2004 at the In Salah Gas Field in Algeria (IEA, 2004b). Several other storage demonstrations are being planned, including one at the Snøhvit Field in the Barents Sea that is expected to come on line in 2007 (IEA, 2004c). However, because storage conditions vary so much from site to site, more demonstrations are needed. Effective storage of CO2 requires a relatively pure stream of CO2. Most of the world’s large-volume point CO2 sources come from fossil fuel power plants. At these sites, CO2 is generated during combustion, mixed with the nitrogen used as combustion air, and then vented at low concentrations as flue gas. Separating and capturing this CO2 is costly. China is one of the few countries where large streams of relatively pure CO2 are available as a result of pre-
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combustion CO2 capture. Most of these large point sources of relatively pure CO2 are at coal-fed ammonia plants that use modern Texaco and Shell gasifiers.2 Because these CO2 streams have already been separated, capturing and using this CO2 for storage demonstration projects is much less costly than CO2 that would be recovered from flue gases of fossil fuel power plants. Although detailed assessments have not been made of the CO2 storage capacity in China, a large number of suitable CO2 storage sites are plausibly available within China’s numerous sedimentary basins. Friedmann (2003) points out that China’s rich Mesozoic–Cenozoic tectonic and stratigraphic history suggest a significant CO2 storage potential. There are possible opportunities for storage in China in all three geological formations that have been recognized as major potential CO2 sinks: deep saline aquifers, depleted oil and natural gas reservoirs, and unminable coal-seams. The geology also suggests possibilities for CO2 enhanced oil recovery (CO2-EOR) and CO2 enhanced coal-bed methane recovery (CO2-ECBM) projects in China. As China’s geology continues to be explored and characterized, its CO2 storage potential will be further clarified. In 1998, China began its first CO2 storage project for CO2-EOR in the Liaohe oil field, one of China’s largest oil fields in the Bohai Basin (IEA, 2004a). More recently, a joint venture was formed between the China United Coal Bed Methane Corporation and the Alberta Research Council of Canada to develop technology for extracting coal-bed methane via CO2 injection (CO2-ECBM). Neither of these projects was motivated by climate change concerns. Rather they were designed to use CO2 to assist in fossil fuel recovery. Nevertheless, these projects are giving China some experience with CO2 storage. In addition, China, in 2003, joined the Carbon Sequestration Leadership Forum (CSLF), a ministerial-level organization initiated by the United States that aims to foster cooperation for CO2 storage projects among the 17 signatory countries. The goal of this study is to identify low-cost demonstration opportunities in China for CO2 storage. To this end, large point sources of relatively pure CO2 emissions were first identified, with a focus on plants that make ammonia from coal. Subsequently, the project focused on locating potential storage formations near the identified CO2 sources. The analyses focused on injecting CO2 into deep saline aquifers, which offer the largest CO2 storage potential. Costs for CO2 compression, transport and storage were estimated for these storage opportunities. Consideration was also given to CO2 storage opportunities in oil reservoirs and coal-beds where there are potential CO2-EOR and CO2-ECBM opportunities.
2 In most countries ammonia is made instead from natural gas, which provides much less CO2 per unit of ammonia produced.
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2. Prospective CO2 sources
2.2. Estimating CO2 emission rates
2.1. Identifying CO2 sources
CO2 emission rates are reported for few of the plants shown in Appendix A. Therefore, emission rates for most plants were estimated based on the reported ammonia output, type of gasification process used, and the CO2 usage rate (primarily for urea and methanol synthesis) at each plant. To estimate the gross amount of CO2 generated at each plant, the ammonia output was multiplied by the CO2 emissions factor for the type of gasification employed. The CO2 emissions factors were estimated for the following four gasifier/feedstock combinations based on reported syngas composition data: Texaco-coal (3.16 t CO2/t NH3), Texaco-oil (2.12 t CO2/t NH3), Shell-coal (3.34 t CO2/t NH3), and Shell-oil (2.22 t CO2/t of NH3). The amount of CO2 used was then subtracted from the gross CO2 emissions to estimate the net CO2 emissions for each plant. For plants where urea production levels were not available, calculations were completed using stoichiometric relationships. It was assumed for these plants that all ammonia would be used to synthesize urea at a rate of 1.76 t urea/t NH3. It was also estimated stoichiometrically that 0.73 t of CO2 are needed to produce 1 t of urea. Another secondary product that requires a substantial amount of CO2 is methanol. Effectively, the amount of CO2 used in methanol synthesis is 1.38 t of CO2/t of methanol.5 For the final list of CO2 sources, the ammonia plants reported in Appendix A with net CO2 emissions less than 400 kt CO2/year were dropped. A demonstration project could in principle be carried out using smaller CO2 sources, but the cost per tonne of CO2 would be much higher than for larger CO2 sources. The final list of CO2 sources for possible demonstration projects consists of nine coal-fed ammonia plants. The annual CO2 emissions at these plants range from 567 kt CO2/year to 1071 kt CO2/year. Fig. 3 shows the location of each of the nine existing and planned ammonia plants in China with net CO2 emission rates in excess of 400 kt/year. The emissions-related values calculated for each plant are presented in Appendix B.
In 2000, 92.5% of the point CO2 emissions in China were the flue gases of fossil fuel power and industrial plants (Hendriks et al, 2002). These streams contain CO2 at low concentrations (generally 8–15%) which make them unattractive for CO2 storage demonstration projects because of the high cost of CO2 capture. However, pure streams of CO2 are available at near atmospheric pressure at plants that consume fossil fuels via gasification (partial oxidation in oxygen extracted from the air via air liquefaction) to make hydrogen. For such plants the cost of CO2 capture is modest—essentially equal to the cost of compressing the CO2 to the pressure (150 atm) needed for CO2 storage projects—because the CO2 has to be separated from the H2 as an inherent part of the H2 manufacturing process. China has extensive experience with modern gasifiers in its ammonia plants where ammonia is made by reacting hydrogen derived from fossil fuel with nitrogen from air. China’s large ammonia plants built over the last two decades are based on modern gasification technology (primarily Texaco3 and Shell gasifiers). In addition, several future plants and retrofits of older plants will also be employing such technology. These plants, fed by both oil and coal, provide H2 needed for ammonia synthesis by separating relatively pure streams of CO2 from the gaseous mixture of mostly H2 and CO2 that forms as a result of the combined processes of gasification and the water gas shift reaction. Typically in China, about half of the CO2 stream is then used to synthesize urea (produced by reacting ammonia with CO2) for fertilizer applications, and the remainder is vented into the atmosphere.4 In order to compile a list of possible CO2 sources for CO2 storage demonstration projects in China, we reviewed the US Department of Energy’s World Gasification Database. The information presented in the database was supplemented and updated with information gathered from site visits to ammonia plants in China, interviews with Chinese ammonia industry experts, and technical experts from Shell and Texaco. After compiling this information, it was found that there are currently six coal-fed and eight oil-fed ammonia plants that use modern gasifiers in China. In addition, as of August of 2004, 10 new gasification projects for ammonia manufacture were being planned. The properties of 18 ammonia plants for which data could be obtained are presented in Appendix A.
3
The Texaco Gasification Process is now owned by GE. China also has many small, much older ammonia plants that synthesize ammonia via the water-gas process, which emits CO2 diluted with N2 from air. CO2 capture costs would be high for these plants. 4
3. Storage opportunities in deep saline aquifers 3.1. Identifying nearby deep saline aquifers One recognized method for locating deep saline aquifers appropriate for CO2 storage is to look for oil- and natural gas-bearing sedimentary basins. It is known that pockets of hydrocarbon form typically during the folding, plugging, and faulting of aquifers (Hitchon et al, 1999). Therefore, 5 Extra H2 beyond that required for making ammonia must be produced from coal to make methanol. Here it is assumed that the methanol is made by reacting extra H2 with CO2 according to the overall reaction CO2+3 H2-CH3OH+H2O. Alternatively, the methanol could be provided by reacting H2 with CO according to the overall reaction CO+2H2CH3OH. Either way the net amount of CO2 available for geological storage is the same.
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Fig. 3. Locations of the nine largest pure CO2 sources among ammonia plants in China.
brine-filled media will typically be found near pockets of known hydrocarbons in sedimentary basins. China has more than 420 sedimentary basins having areas of 2000 km2 or greater (Zhai, 1999). In order to locate petroliferous sedimentary basins near the identified CO2 sources, data were taken from a US Geological Survey (USGS) database on South Asia compiled by Hearn et al. (2001). The USGS database indicates the locations of China’s major sedimentary basins as well as the locations of known oil and gas fields. The nine identified ammonia plants were mapped in relation to China’s sedimentary basins and known oil and gas fields using ArcMap GIS software. Fig. 4 is the rendered image. Surrounding each CO2 point source are zones with radii of 50, 100 and 150 km. Fig. 4 shows that there are four concentrated CO2 sources at ammonia plants that are located within 150 km of known oil and gas fields. They are the Nanjing Chemical Industry Plant, the Dong Ting Ammonia Plant, the Hubei Ammonia Plant and the Yuntianhua Chemical Group Plant. However, because the USGS database provides oil and gas fields only as point sources and does not supply the field’s name, size or hydrocarbon properties, further visual information was obtained from a map of China’s oil and gas fields compiled for the Oil and Gas Journal (Williams, 1995). A complete dataset of reservoir properties including size, depth, thickness, permeability of the reservoir as well as the specific gravity of the oil found was obtained for some of the identified oil and gas fields from ‘‘The
Collection of China’s basins which contain oil and gas’’, a report published by China’s Petrolic Industry Press (Li, 2002). Analyses were carried out only for fields where a complete set of data was obtained. Figs. 5–8 below show each of the four ammonia plants mapped onto the Oil and Gas Journal’s ‘‘Oil and Gas Map of China’’. Fig. 5 places the Nanjing Chemical Industry Plant in relation to oil fields in the Subei Basin. Of the oil fields in the Subei Basin located within 150 km of the source for which a full set of data could be obtained, the Zhenwu oil field was the largest. Fig. 6 shows the Dong Ting Ammonia Plant and nearby oil fields in the Jianghan Basin. Among the oil fields within 150 km of the plant for which a complete data set was obtained, the Wangchang oil field was the largest. Fig. 7 shows the Hubei Ammonia Plant and nearby oil fields also in the Jianghan Basin. Again, the Wangchang oil field is the largest of the oil fields within 150 km of the plant. Finally, Fig. 8 shows the Yuntianhua Chemical Group Plant in relation to natural gas fields in the Sichuan Basin. Within 150 km of the plant, the Weiyuan gas field is the largest among the fields in which a full dataset could be obtained. 3.2. Estimating CO2 capture and storage costs for prospective demonstration projects Demonstration project costs were estimated for the four pairings of CO2 sources and sinks identified. It was
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Fig. 4. CO2 sources mapped onto sedimentary basins along with known oil and gas fields.
assumed that costs for the demonstration projects are dominated by CO2 compression, transport, and storage. Monitoring, modeling and assessment costs for the project are expected to be much lower and are thus neglected (Friedmann, 2005). CO2 compression costs are based on a model developed by Larson and Ren (2003), assuming an electricity price of $0.032/kWh (average for Chinese industry in 1996). Costs for CO2 transport and storage are based on a model developed by Ogden (2002), except that maximum injectivities per CO2 storage well were estimated in the current study. In all cases considered, it is assumed that plants are operated at full capacity for 300 days annually and that demonstration projects last 20 years. Because a range of permeability values was obtained for each of the four oil and gas fields, the maximum injectivity per well was estimated for three cases: low, mean and high permeability values. Due to high reported permeability values and the fact that none of the CO2 flows exceeded
1.2 Mt CO2/year, only one injection well was needed for all projects based on mean and high permeability values. For the low permeability cases, only CO2 disposal in the Weiyuan field required more than 1 injection well. The physical characteristics and estimated costs for the prospective CO2 storage demonstration projects are presented in Appendix C. The total required capital investment ranges from $56 to $71 million per project. Specific costs range from $15 to $21/t of CO2. Total project costs range from $13 million to $18 million per year. 4. Exploring EOR and ECBM opportunities in China 4.1. CO2-EOR opportunities For some mature oil fields injecting CO2 into old wells can lead to extra oil production via CO2-EOR. China has expressed interest in this technology. Several years ago, China’s Ministry of Petroleum Industry (MOPI)
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Fig. 5. Nanjing Chemical Industry Plant mapped onto nearby oil fields. Zones: 50, 100, 150 km.
Fig. 6. Dong Ting Ammonia Plant mapped onto nearby oil fields. Zones: 50, 100, 150 km.
commissioned an evaluation of oil fields suitable for CO2EOR projects in China. The study estimated that of the 3.8 billion barrels of oil (BBO) remaining in China’s depleted oil fields, 500 million barrels might be recoverable using CO2-EOR (Liu et al, 1998). Considering that in 2001 China consumed oil at a rate of 5 million barrels per day (IEO, 2005), EOR based on this potential resource estimate is a trivial option for extending China’s oil supplies (providing
100 day oil supply for China). However, CO2-EOR projects might be suitable for CO2 storage demonstration projects. Fig. 4 shows that there are three ammonia plants located within 150 km of known oil fields. The potential CO2-EOR pairings are the Nanjing Chemical Industry Plant–Zhenwu oil field, the Dong Ting Ammonia Plant–Wangchang oil field, and the Hubei Ammonia Plant–Wangchang oil field.
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The CO2-EOR potential and CO2 required for each oil field was estimated based on a method developed by Stevens et al. (1999) and adopted by Lysen et al. (2002). The Zhenwu field is the largest of those considered with an estimated EOR potential of 34 million barrels of oil
(MMBO) that can be recovered using 16.3 Mt CO2. The Wangchang field has an estimated EOR potential of 29.8 MMBO which would require 16.7 Mt CO2. Appendix D shows the EOR potential and associated CO2 storage capacity of the two oil fields. The costs for CO2 compression and transport are $15/t, $16/t, and $19/t CO2 for the Nanjing–Zhenwu, Dong Ting–Wangchang and Hubei–Wangchang projects, respectively (see Appendix C). It is likely that the CO2 could be sold to a CO2EOR producer at prices greater than or equal to these costs if the oil price is $30 a barrel or more—based on a ‘‘rule of thumb’’ for CO2-EOR projects in the United States that an appropriate average CO2 price in $/t is 57% of the oil price in $ per barrel (Kuuskraa, 2005). For comparison, the world oil price averaged $50 a barrel during the first 10 months of 2005 and is likely to remain well above $30 a barrel for the indefinite future. 4.2. CO2-ECBM opportunities
Fig. 7. Hubei Ammonia Plant mapped onto nearby oil fields. Zones: 50, 100, 150 km.
CO2 can be stored in beds of unminable coal and in some instances CO2-ECBM might be feasible. Though CO2ECBM is a much more embryonic technology than CO2EOR, China’s large coal resources have generated much CO2-ECBM interest. In 1999, a joint project was initiated between the Alberta Research Council (ARC) and the China United Coal Bed Methane Corporation (CUCBM) to address a number of issues that might lead to a CO2ECBM demonstration project in China. Though it is still in the development phase, the project aims to compile an inventory of suitable coal-beds for CO2-ECBM and perform micro-pilot and large-scale tests in China.
Fig. 8. Yuntianhua Chemical Group mapped onto nearby gas fields. Buffer zones: 50, 100, 150 km.
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Fig. 9. China’s ECBM regions. Source: Stevens and Kuuskraa (1998).
5. Conclusions
Fig. 10. China’s premier CO2-ECBM regions mapped in relation to identified CO2 sources.
China’s coal bed methane (CBM) potential is estimated to be one of the world’s largest—between 16,000 and 35,000 GNm3 (Zhang and Zhang, 1996). However, the CO2-ECBM potential is uncertain. Stevens and Kuuskraa (1998) identifies the Ordos Basin and the Northeast China Coal Region as regions with the greatest CO2-ECBM potential. These regions are shown in Fig. 9. The Ordos Basin has a coal-bed methane resource of 445 GNm3, a possible CO2-ECBM recovery potential of 180 GNm3 (about a 2 year natural gas supply at the average rate expected for China during 2001–2025), and a corresponding CO2 storage potential of 660 Mt CO2. The NE China Coal Region is estimated to have a coal-bed methane resource of 55 GNm3, a CO2-ECBM recovery potential of 5.5 GNm3, and a CO2 storage potential of 21 Mt CO2. Although prospective CO2 storage volumes at these two sites are trivial in relation to China’s CO2 emission rate (3322 Mt CO2 in 2002), CO2 storage demonstration projects might plausibly be associated with CO2-ECBM projects in these regions. Of the nine ammonia plants identified as potential CO2 sources for demonstration projects, the Weihe, Huainan and Nanjing ammonia plants are located closest to the Ordos and NE China coal-bearing regions (Fig. 10).
Relatively low-cost CO2 storage demonstration projects could be carried out at a number of sites in China where low-cost concentrated CO2 is available at coal-fed ammonia plants that are near underground sites where CO2 might be stored. Nine currently operating or planned ammonia plants were identified where the streams of essentially pure CO2 are available at annual flow rates between 570 and 1070 kt of CO2 per year. Based on these CO2 sources, four possible CO2 storage demonstration projects for storage in deep saline aquifers were identified. The costs for compressing, transporting and storing the CO2 for these projects ranged from $15 to $21/t of CO2, the corresponding total project costs range from $15 million to $18 million dollars per year, and the investment required per project ranges from $56 million to $71 million. Three possible CO2-EOR projects were identified for two oil fields, each with a CO2-EOR potential of about 30 MMBO and requiring about 16 Mt CO2. These CO2-EOR projects are likely to be economically attractive without subsidy at oil prices of the order of $30 a barrel or more. Before the CO2 storage demonstration opportunities identified in this paper can be implemented, in-depth, sitespecific studies are needed to corroborate and update the information presented here. Of the nine ammonia plants listed as potential CO2 sources, first-hand data was obtained only for the Nanjing Chemical Industry Plant. The CO2 emissions for the remaining eight plants were estimated based on published ammonia and urea production rates and the gasification process used. Furthermore, the data should be updated to reflect the ongoing shift from oil gasification to coal gasification; of the nine ammonia plants identified as potential CO2 sources for a CO2 storage demonstration project, only three plants currently use coal gasification technology. The other six ammonia plants (all of which are
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contracted to employ the Shell Coal Gasification Process) will begin operation on coal in the near future. Since ammonia production rates could be different once operation on coal begins, it is desirable to update the data provided here in order to take into account the latest developments in China’s ammonia industry. Site-specific analyses are also needed for the identified CO2 storage sites to better assess their suitability for demonstration projects. The analyses completed on CO2 storage are based on geological data obtained from a report published by China’s Petrolic Industry Press and was not corroborated by other sources nor by any geological surveying. Assessments at each of the three identified storage sites should aim to better understand geological properties, particularly the permeabilities of the oil and gas fields. Funding for CO2 storage demonstration projects in China would most likely come from some mix of government, multinational agency, and private company sources—with most of the needed funding coming from sources outside of China.
Successful CO2 capture and storage demonstrations in China and elsewhere could help pave the way for eventual widespread deployment of these technologies both in China and the rest of the world. Appendix A Properties of CO2 sources in China (see Table A1). Appendix B Properties of identified CO2 sources (see Table B1). Appendix C Physical characteristics and estimated costs for prospective CO2 capture and storage demonstration projects (see Table C1). Appendix D CO2-EOR production potential and associated CO2 storage potential (see Table D1).
Table A1 Name
Location
Gasifier
Status
Year
Main feed
] of operating/ spare gasifiers
Fuel input
Syngas capacity (Nm3/d)
Anhui Ammonia Plant (Sinopec)a
Anqing, Anhui
Shell
C
2006
Coal
1/0
2000 t/day
3,400,000
Dahua Chemical Industrial Corp.
Dalian, Liaoning
TexacoShell
Cb
2006b
Oil-coalb
1/0
1000 t/dayb
1,500,000b
Dong Ting Ammonia Plant (Sinopec-Shell)a
Yueyang, Hunan
Shell
C
2005
Coal
1/0
2000 t/day
3,400,000
Huainan Chemical General Works
Huainan, Anhui
Texaco
O
2000b
Coal
2/0
255 MWth
1,400,000
Hubei Ammonia Plant (Sinopec)a
Zhijiang, Hubei
Shell
C
2006
Coal
1/0b
2000 t/day
3,400,000
Inner Mongolia Fertilizer Co.
Hohhot, Inner Mongolia
Shell
O
1996
Vacuum residue
2/0
326 MWth
2,100,000
Jilin Chemical Industrial Corp.
Jilin, Jilin
Texaco
C
2000
Visbreaker residue
2/0
358 MWth
2,096,500
Jiujiang Petrochemical Co.
Juijiang, Jiangxi
Shell
O
1996
Vacuum residue
2/0
326 MWth
2,100,000
Lanzhou Chemical Industrial Co.
Lanzhou, Gansu
Shell
O
1998
Vacuum residue
2/0
350 MWth
2,100,000
Liuzhou Chemicala
Liuzhou, Guangxi
Shell
C
2005
Coal
1/0
1200 t/day
2,100,000
Lunan Chemical Co.
Tengzhou, Shandong
Texaco
O
1993
Bit. Coal
2/1b
1000 t/dayb
1,776,000b
Nanjing Chemical Industry Co.
Nanjing, Jiangsu
Texaco
Cb
2004b
Oil-coalb
2/1b
358 MWth
4,045,080b
Shuanghuan Chemicala
Yingcheng, Hubei
Shell
C
2004
Coal
1/0
900 t/day
1,300,000
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Table A1 (continued ) Urumqi Chemical Plant
Urumqi, Xinjiang
Texaco
O
1985
Visbreaker residue, gasb
3/0
358 MWth
2,100,000
Weihe Fertilizer Co.
Weinan, Shaanxi
Texaco
O
1996
Coal
2/1
372 MWth
2,040,000
Yuntianhua Chemical Groupa
Shuifu, Yunnan
Shell
C
2006
Coal
1/0
2000 t/day
3,400,000
Yunzhanhua Chemicalsa
Qujing, Yunnan
Shell
C
2006
Coal
1/0
2000 t/day
3,400,000
Zhenhai Refining and Chemical Co.
Ningbo, Zhejiang
Texaco
O
1983
Visbreaker residue
3/0
350 MWth
2,100,000
C indicates plant currently under construction and O indicates plant currently in operation. a
Indicates new gasifier not included in DOE Gasification Database. Indicates an update from DOE World Gasification Database.
b
Table B1 Name
Location
Gasifier
Secondary product(s) (kt/y)
CO2 uses (kt CO2/y)
NH3 production (kt/y)
Gross CO2 (kt/y)
Total CO2 used (kt/y)
Net avail. CO2 (kt/y)
Anhui Ammonia Plant
Anqing, Anhui
Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Dong Ting Ammonia Plant
Yueyang, Hunan Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Huainan Chemical General Works
Huainan, Anhui
Texaco
Urea: 300 MeOH: 50 Urea: 219 NH4NO3: 110 MeOH: 69
360
1138
288
850
Hubei Ammonia Plant
Zhijiang, Hubei
Shell
Urea: 582
330
1297
428
869
Liuzhou Ammonia Plant
Liuzhou, Guangxi
Shell
Urea: 300 MeOH: 100 Urea: 220 NH4NO3: 180 MeOH: 37.5
300
1002
358
645
Nanjing Chemical Industry Co.
Nanjing, Jiangsu Texaco
Urea: 520 H2: oil refinery
Urea: 381.3 Dry ice: 40
300
1493
421
1071
Weihe Fertilizer Co. Weinan, Shaanxi Texaco
Urea: 520
Urea: 381.3
300
948
381
567
Yuntianhua Chemical Group
Shuifu, Yunnan
Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Yunzhanhua Chemicals
Qujing, Yunnan
Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Urea: 427 Drinks: 0.067
Table C1 Project
NanjingZhenwu
CO2 vol. (kt/y)
1071
Avg API
38
Dist. (km)
120
Well depth Case (km)
2.71
Perm. (mD)
Max. injectivity (ton/day)
Mean K
1110
150,000
Min K
95
6600
# Wells
1
Costs for CO2 compression, transport, and storage
Cost component
Capital investment (million $)
Specific cost ($/t CO2)
Annual cost (million $/year)
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
16 42.7 58.7 5.5 0 64.2
6.4 8.9 15.3 1.1 0 16.4
17.6
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Table C1 (continued ) Dong TingWangchang
HubeiWangchang
YuntianhuaWeiyuan
869
869
869
24
24
N/A
115
145
85
2.61
2.61
3.24
1
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
13.9 38.2 52.1 5.3 0 57.4
6.7 9.4 16.1 1.4 0 17.4
15.1
1
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
13.9 40.4 54.3 5.3 0 59.6
6.7 12.5 19.2 1.4 0 20.5
17.8
21,000
1
3
13.9 35.6 49.5 6.3 0 55.7 13.9 35.6 49.5 18.9 2.5 70.9
6.7 6.4 13.1 1.6 0 14.7 6.7 6.4 13.1 4.8 0.6 18.6
12.8
1100
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
Mean K
1300
53,000
Min K
75
3000
Mean K
1300
53,000
Min K
75
3000
Mean K
20
Min K
1
Table D1 Basin
Subei
Jianghan
Field Depth (m) Thickness (m) Avg. API URR (MMBO) OOIP (MMBO) EOR (MMBO) Total CO2 (Mt)
Zhenwu 2710 17 38 136 316 34 16.3
Wangchang 2610 10 24 217 750 29.8 16.7
References Energy Information Agency (EIA), 2005. International Energy Outlook 2005, Washington DC. Friedmann, J.S., 2003. Storing carbon in earth. Geotimes, March, pp. 16–20. Friedmann, S.J., 2005. Lawrence Livermore Laboratory, private communication. April. Hearn Jr., P., Hare, T., Schruben, P., Sherril, D., LaMar, C., Tsushima, P., 2001. Global GIS Database: Digital Atlas of South Asia. US Geological Survey. Digital Data Series DDS-62-C. Hendriks, C., van der Waart, A.S., Byers, C., Phylipsen, D., Voogt, M., Hofman, Y., 2002. Building the cost curve for CO2 storage: sources of CO2. Ecofys, Ultrecht. Hitchon, B., Gunter, W.D., Gentzis, T., Bailey, R.T., 1999. Sedimentary basins and greenhouse gases: a serendipitous association. Energy Conversion and Management 40, 825–843.
16.1
International Energy Agency (IEA), 2004a. EOR Application at Liaohe Oil Field in China. IEA Greenhouse Gas R&D Programme. International Energy Agency (IEA), 2004b. In: Salah Project. IEA Greenhouse Gas R&D Programme Database. International Energy Agency (IEA), 2004c. Snøhvit Offshore CO2 Storage Project. Greenhouse Issues, 72. Kuuskraa, V.A., 2005. Advanced Resources International. Private communication, December. Larson, E.D., Ren, T., 2003. Synthetic fuels production by indirect coal liquefaction. Energy for Sustainable Development, December. Li, Guoyu, 2002. The collection of China’s Basins which contain oil and gas. 2nd ed. The Petrolic Industry Press. Liu, D.S., Yun, G.C., Ou Yang, L.H., 1998. Waste CO2 capture and utilization for enhanced oil recovery (EOR) and underground storage—a case study in Jilin Oil Field, China. Greenhouse gas mitigation: technologies for activities implemented jointly. Elsevier, Oxford, UK (pp. 273–279). Lysen, E.H., ed., 2002. Opportunities for early application of CO2 sequestration technology. IEA Report No. Ph 4/10. Ogden, J., 2002. Modeling infrastructure for a fossil hydrogen energy system with CO2 sequestration. GHGT-6, Kyoto, Japan. Stevens, S.H., Kuuskraa, V.A., 1998. Enhanced coal bed methane recovery with CO2 sequestration. IEA Report No. PH3/3. Stevens, S.H., Kuuskraa, V.A., Taber, J.J., 1999. Barriers to overcome in implementation of CO2 capture and storage (disused Oil and Gas Fields). IEA Report No. PH 3/22. Williams, B., 1995. Oil and Gas Map of China. Oil and Gas Journal, Pennwell Publishing. Zhai, G., 1997. China Well Evaluation Conference: Oil and gas resources and their future development in China. Schlumberger Oilfield Services. Zhang, X., Zhang, X., 1996. Distribution and development of strategy for coal bed methane resources in China. United Nations International Conference on Coal Bed Methane Development and Utilization, Beijing, pp. 19–24.
Energy Policy 35 (2007) 2368–2378 www.elsevier.com/locate/enpol
Opportunities for low-cost CO2 storage demonstration projects in China Kyle C. Menga,,1, Robert H. Williamsb, Michael A. Celiaa a
Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ, USA b Princeton Environmental Institute, Princeton University, Princeton, NJ, USA Received 20 March 2006; accepted 25 August 2006 Available online 27 October 2006
Abstract Several CO2 storage demonstration projects are needed in a variety of geological formations worldwide to prove the viability of CO2 capture and storage as a major option for climate change mitigation. China has several low-cost CO2 sources at sites that produce NH3 from coal via gasification. At these plants, CO2 generated in excess of the amount needed for other purposes (e.g., urea synthesis) is vented as a relatively pure stream. These CO2 sources would potentially be economically interesting candidates for storage demonstration projects if there are suitable storage sites nearby. In this study a survey was conducted to estimate CO2 availability at modern Chinese coal-fed ammonia plants. Results indicate that annual quantities of available, relatively pure CO2 per site range from 0.6 to 1.1 million tonnes. The CO2 source assessment was complemented by analysis of possible nearby opportunities for CO2 storage. CO2 sources were mapped in relation to China’s petroliferous sedimentary basins where prospective CO2 storage reservoirs possibly exist. Four promising pairs of sources and sinks were identified. Project costs for storage in deep saline aquifers were estimated for each pairing ranging from $15–21/t of CO2. Potential enhanced oil recovery and enhanced coal bed methane recovery opportunities near each prospective source were also considered. r 2006 Elsevier Ltd. All rights reserved. Keywords: Ammonia from coal; China; Carbon capture and storage
1. Introduction According to the International Energy Outlook 2005 (IEO2005), prepared by the Energy Information Administration of the US Department of Energy, China was the world’s second largest emitter of CO2 after the United States in 2002, contributing 13.6% of total world CO2 emissions or 3322 megatonnes (Mt) of CO2. In its Reference Case scenario, the IEO2005 projects that China’s CO2 emissions will grow 4.0% per year (the highest rate in the world), reaching 8133 Mt CO2 by 2025, at which point China’s share of world CO2 emissions is projected to reach 21%. By contrast, the IEO2005 projects that the US share of world CO2 emissions will decrease Corresponding author. Tel.: +1 212 616 1278.
E-mail addresses: [email protected] (K.C. Meng), [email protected] (R.H. Williams), [email protected] (M.A. Celia). 1 Now with Environmental Defense. 0301-4215/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.enpol.2006.08.016
from 24% to 21% during 2002–2025 and that in 2025, US emissions will be 98% of China’s (Figs. 1 and 2). This projected increase in China’s CO2 emissions is largely due to its rising energy demand. Between 2002 and 2025, China’s primary annual energy consumption is estimated to grow from 45.6 to 115.2 EJ, increasing its percentage of total world energy consumption in this period from 10% to 17%. Due to its abundant coal resources, the paucity of its oil and gas resources, and high world oil prices, China is expected to meet more than half of its incremental energy in this period with coal, the most carbon-intensive of the fossil fuels (IEO, 2005). Because of this heavy dependence on coal, it is likely that under a climate change mitigation policy, China will emphasize CO2 capture and storage for the coal-based part of its energy economy. Although CO2 capture is proven technologically, CO2 storage must be tested and analyzed in a variety of geological media through large-scale (1 Mt/year CO2 per project) demonstration projects before it can be
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Fig. 1. Historic and projected CO2 emissions by region. Source: US DOE, IEO2005.
Fig. 2. Percentage of world CO2 emissions by region. Source: US DOE, IEO2005.
implemented routinely with confidence as a major climate change mitigation strategy. Already storage demonstration projects of this scale have been underway since 1996 at the Sleipner Gas Field in the North Sea and since 2004 at the In Salah Gas Field in Algeria (IEA, 2004b). Several other storage demonstrations are being planned, including one at the Snøhvit Field in the Barents Sea that is expected to come on line in 2007 (IEA, 2004c). However, because storage conditions vary so much from site to site, more demonstrations are needed. Effective storage of CO2 requires a relatively pure stream of CO2. Most of the world’s large-volume point CO2 sources come from fossil fuel power plants. At these sites, CO2 is generated during combustion, mixed with the nitrogen used as combustion air, and then vented at low concentrations as flue gas. Separating and capturing this CO2 is costly. China is one of the few countries where large streams of relatively pure CO2 are available as a result of pre-
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combustion CO2 capture. Most of these large point sources of relatively pure CO2 are at coal-fed ammonia plants that use modern Texaco and Shell gasifiers.2 Because these CO2 streams have already been separated, capturing and using this CO2 for storage demonstration projects is much less costly than CO2 that would be recovered from flue gases of fossil fuel power plants. Although detailed assessments have not been made of the CO2 storage capacity in China, a large number of suitable CO2 storage sites are plausibly available within China’s numerous sedimentary basins. Friedmann (2003) points out that China’s rich Mesozoic–Cenozoic tectonic and stratigraphic history suggest a significant CO2 storage potential. There are possible opportunities for storage in China in all three geological formations that have been recognized as major potential CO2 sinks: deep saline aquifers, depleted oil and natural gas reservoirs, and unminable coal-seams. The geology also suggests possibilities for CO2 enhanced oil recovery (CO2-EOR) and CO2 enhanced coal-bed methane recovery (CO2-ECBM) projects in China. As China’s geology continues to be explored and characterized, its CO2 storage potential will be further clarified. In 1998, China began its first CO2 storage project for CO2-EOR in the Liaohe oil field, one of China’s largest oil fields in the Bohai Basin (IEA, 2004a). More recently, a joint venture was formed between the China United Coal Bed Methane Corporation and the Alberta Research Council of Canada to develop technology for extracting coal-bed methane via CO2 injection (CO2-ECBM). Neither of these projects was motivated by climate change concerns. Rather they were designed to use CO2 to assist in fossil fuel recovery. Nevertheless, these projects are giving China some experience with CO2 storage. In addition, China, in 2003, joined the Carbon Sequestration Leadership Forum (CSLF), a ministerial-level organization initiated by the United States that aims to foster cooperation for CO2 storage projects among the 17 signatory countries. The goal of this study is to identify low-cost demonstration opportunities in China for CO2 storage. To this end, large point sources of relatively pure CO2 emissions were first identified, with a focus on plants that make ammonia from coal. Subsequently, the project focused on locating potential storage formations near the identified CO2 sources. The analyses focused on injecting CO2 into deep saline aquifers, which offer the largest CO2 storage potential. Costs for CO2 compression, transport and storage were estimated for these storage opportunities. Consideration was also given to CO2 storage opportunities in oil reservoirs and coal-beds where there are potential CO2-EOR and CO2-ECBM opportunities.
2 In most countries ammonia is made instead from natural gas, which provides much less CO2 per unit of ammonia produced.
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2. Prospective CO2 sources
2.2. Estimating CO2 emission rates
2.1. Identifying CO2 sources
CO2 emission rates are reported for few of the plants shown in Appendix A. Therefore, emission rates for most plants were estimated based on the reported ammonia output, type of gasification process used, and the CO2 usage rate (primarily for urea and methanol synthesis) at each plant. To estimate the gross amount of CO2 generated at each plant, the ammonia output was multiplied by the CO2 emissions factor for the type of gasification employed. The CO2 emissions factors were estimated for the following four gasifier/feedstock combinations based on reported syngas composition data: Texaco-coal (3.16 t CO2/t NH3), Texaco-oil (2.12 t CO2/t NH3), Shell-coal (3.34 t CO2/t NH3), and Shell-oil (2.22 t CO2/t of NH3). The amount of CO2 used was then subtracted from the gross CO2 emissions to estimate the net CO2 emissions for each plant. For plants where urea production levels were not available, calculations were completed using stoichiometric relationships. It was assumed for these plants that all ammonia would be used to synthesize urea at a rate of 1.76 t urea/t NH3. It was also estimated stoichiometrically that 0.73 t of CO2 are needed to produce 1 t of urea. Another secondary product that requires a substantial amount of CO2 is methanol. Effectively, the amount of CO2 used in methanol synthesis is 1.38 t of CO2/t of methanol.5 For the final list of CO2 sources, the ammonia plants reported in Appendix A with net CO2 emissions less than 400 kt CO2/year were dropped. A demonstration project could in principle be carried out using smaller CO2 sources, but the cost per tonne of CO2 would be much higher than for larger CO2 sources. The final list of CO2 sources for possible demonstration projects consists of nine coal-fed ammonia plants. The annual CO2 emissions at these plants range from 567 kt CO2/year to 1071 kt CO2/year. Fig. 3 shows the location of each of the nine existing and planned ammonia plants in China with net CO2 emission rates in excess of 400 kt/year. The emissions-related values calculated for each plant are presented in Appendix B.
In 2000, 92.5% of the point CO2 emissions in China were the flue gases of fossil fuel power and industrial plants (Hendriks et al, 2002). These streams contain CO2 at low concentrations (generally 8–15%) which make them unattractive for CO2 storage demonstration projects because of the high cost of CO2 capture. However, pure streams of CO2 are available at near atmospheric pressure at plants that consume fossil fuels via gasification (partial oxidation in oxygen extracted from the air via air liquefaction) to make hydrogen. For such plants the cost of CO2 capture is modest—essentially equal to the cost of compressing the CO2 to the pressure (150 atm) needed for CO2 storage projects—because the CO2 has to be separated from the H2 as an inherent part of the H2 manufacturing process. China has extensive experience with modern gasifiers in its ammonia plants where ammonia is made by reacting hydrogen derived from fossil fuel with nitrogen from air. China’s large ammonia plants built over the last two decades are based on modern gasification technology (primarily Texaco3 and Shell gasifiers). In addition, several future plants and retrofits of older plants will also be employing such technology. These plants, fed by both oil and coal, provide H2 needed for ammonia synthesis by separating relatively pure streams of CO2 from the gaseous mixture of mostly H2 and CO2 that forms as a result of the combined processes of gasification and the water gas shift reaction. Typically in China, about half of the CO2 stream is then used to synthesize urea (produced by reacting ammonia with CO2) for fertilizer applications, and the remainder is vented into the atmosphere.4 In order to compile a list of possible CO2 sources for CO2 storage demonstration projects in China, we reviewed the US Department of Energy’s World Gasification Database. The information presented in the database was supplemented and updated with information gathered from site visits to ammonia plants in China, interviews with Chinese ammonia industry experts, and technical experts from Shell and Texaco. After compiling this information, it was found that there are currently six coal-fed and eight oil-fed ammonia plants that use modern gasifiers in China. In addition, as of August of 2004, 10 new gasification projects for ammonia manufacture were being planned. The properties of 18 ammonia plants for which data could be obtained are presented in Appendix A.
3
The Texaco Gasification Process is now owned by GE. China also has many small, much older ammonia plants that synthesize ammonia via the water-gas process, which emits CO2 diluted with N2 from air. CO2 capture costs would be high for these plants. 4
3. Storage opportunities in deep saline aquifers 3.1. Identifying nearby deep saline aquifers One recognized method for locating deep saline aquifers appropriate for CO2 storage is to look for oil- and natural gas-bearing sedimentary basins. It is known that pockets of hydrocarbon form typically during the folding, plugging, and faulting of aquifers (Hitchon et al, 1999). Therefore, 5 Extra H2 beyond that required for making ammonia must be produced from coal to make methanol. Here it is assumed that the methanol is made by reacting extra H2 with CO2 according to the overall reaction CO2+3 H2-CH3OH+H2O. Alternatively, the methanol could be provided by reacting H2 with CO according to the overall reaction CO+2H2CH3OH. Either way the net amount of CO2 available for geological storage is the same.
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Fig. 3. Locations of the nine largest pure CO2 sources among ammonia plants in China.
brine-filled media will typically be found near pockets of known hydrocarbons in sedimentary basins. China has more than 420 sedimentary basins having areas of 2000 km2 or greater (Zhai, 1999). In order to locate petroliferous sedimentary basins near the identified CO2 sources, data were taken from a US Geological Survey (USGS) database on South Asia compiled by Hearn et al. (2001). The USGS database indicates the locations of China’s major sedimentary basins as well as the locations of known oil and gas fields. The nine identified ammonia plants were mapped in relation to China’s sedimentary basins and known oil and gas fields using ArcMap GIS software. Fig. 4 is the rendered image. Surrounding each CO2 point source are zones with radii of 50, 100 and 150 km. Fig. 4 shows that there are four concentrated CO2 sources at ammonia plants that are located within 150 km of known oil and gas fields. They are the Nanjing Chemical Industry Plant, the Dong Ting Ammonia Plant, the Hubei Ammonia Plant and the Yuntianhua Chemical Group Plant. However, because the USGS database provides oil and gas fields only as point sources and does not supply the field’s name, size or hydrocarbon properties, further visual information was obtained from a map of China’s oil and gas fields compiled for the Oil and Gas Journal (Williams, 1995). A complete dataset of reservoir properties including size, depth, thickness, permeability of the reservoir as well as the specific gravity of the oil found was obtained for some of the identified oil and gas fields from ‘‘The
Collection of China’s basins which contain oil and gas’’, a report published by China’s Petrolic Industry Press (Li, 2002). Analyses were carried out only for fields where a complete set of data was obtained. Figs. 5–8 below show each of the four ammonia plants mapped onto the Oil and Gas Journal’s ‘‘Oil and Gas Map of China’’. Fig. 5 places the Nanjing Chemical Industry Plant in relation to oil fields in the Subei Basin. Of the oil fields in the Subei Basin located within 150 km of the source for which a full set of data could be obtained, the Zhenwu oil field was the largest. Fig. 6 shows the Dong Ting Ammonia Plant and nearby oil fields in the Jianghan Basin. Among the oil fields within 150 km of the plant for which a complete data set was obtained, the Wangchang oil field was the largest. Fig. 7 shows the Hubei Ammonia Plant and nearby oil fields also in the Jianghan Basin. Again, the Wangchang oil field is the largest of the oil fields within 150 km of the plant. Finally, Fig. 8 shows the Yuntianhua Chemical Group Plant in relation to natural gas fields in the Sichuan Basin. Within 150 km of the plant, the Weiyuan gas field is the largest among the fields in which a full dataset could be obtained. 3.2. Estimating CO2 capture and storage costs for prospective demonstration projects Demonstration project costs were estimated for the four pairings of CO2 sources and sinks identified. It was
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Fig. 4. CO2 sources mapped onto sedimentary basins along with known oil and gas fields.
assumed that costs for the demonstration projects are dominated by CO2 compression, transport, and storage. Monitoring, modeling and assessment costs for the project are expected to be much lower and are thus neglected (Friedmann, 2005). CO2 compression costs are based on a model developed by Larson and Ren (2003), assuming an electricity price of $0.032/kWh (average for Chinese industry in 1996). Costs for CO2 transport and storage are based on a model developed by Ogden (2002), except that maximum injectivities per CO2 storage well were estimated in the current study. In all cases considered, it is assumed that plants are operated at full capacity for 300 days annually and that demonstration projects last 20 years. Because a range of permeability values was obtained for each of the four oil and gas fields, the maximum injectivity per well was estimated for three cases: low, mean and high permeability values. Due to high reported permeability values and the fact that none of the CO2 flows exceeded
1.2 Mt CO2/year, only one injection well was needed for all projects based on mean and high permeability values. For the low permeability cases, only CO2 disposal in the Weiyuan field required more than 1 injection well. The physical characteristics and estimated costs for the prospective CO2 storage demonstration projects are presented in Appendix C. The total required capital investment ranges from $56 to $71 million per project. Specific costs range from $15 to $21/t of CO2. Total project costs range from $13 million to $18 million per year. 4. Exploring EOR and ECBM opportunities in China 4.1. CO2-EOR opportunities For some mature oil fields injecting CO2 into old wells can lead to extra oil production via CO2-EOR. China has expressed interest in this technology. Several years ago, China’s Ministry of Petroleum Industry (MOPI)
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Fig. 5. Nanjing Chemical Industry Plant mapped onto nearby oil fields. Zones: 50, 100, 150 km.
Fig. 6. Dong Ting Ammonia Plant mapped onto nearby oil fields. Zones: 50, 100, 150 km.
commissioned an evaluation of oil fields suitable for CO2EOR projects in China. The study estimated that of the 3.8 billion barrels of oil (BBO) remaining in China’s depleted oil fields, 500 million barrels might be recoverable using CO2-EOR (Liu et al, 1998). Considering that in 2001 China consumed oil at a rate of 5 million barrels per day (IEO, 2005), EOR based on this potential resource estimate is a trivial option for extending China’s oil supplies (providing
100 day oil supply for China). However, CO2-EOR projects might be suitable for CO2 storage demonstration projects. Fig. 4 shows that there are three ammonia plants located within 150 km of known oil fields. The potential CO2-EOR pairings are the Nanjing Chemical Industry Plant–Zhenwu oil field, the Dong Ting Ammonia Plant–Wangchang oil field, and the Hubei Ammonia Plant–Wangchang oil field.
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The CO2-EOR potential and CO2 required for each oil field was estimated based on a method developed by Stevens et al. (1999) and adopted by Lysen et al. (2002). The Zhenwu field is the largest of those considered with an estimated EOR potential of 34 million barrels of oil
(MMBO) that can be recovered using 16.3 Mt CO2. The Wangchang field has an estimated EOR potential of 29.8 MMBO which would require 16.7 Mt CO2. Appendix D shows the EOR potential and associated CO2 storage capacity of the two oil fields. The costs for CO2 compression and transport are $15/t, $16/t, and $19/t CO2 for the Nanjing–Zhenwu, Dong Ting–Wangchang and Hubei–Wangchang projects, respectively (see Appendix C). It is likely that the CO2 could be sold to a CO2EOR producer at prices greater than or equal to these costs if the oil price is $30 a barrel or more—based on a ‘‘rule of thumb’’ for CO2-EOR projects in the United States that an appropriate average CO2 price in $/t is 57% of the oil price in $ per barrel (Kuuskraa, 2005). For comparison, the world oil price averaged $50 a barrel during the first 10 months of 2005 and is likely to remain well above $30 a barrel for the indefinite future. 4.2. CO2-ECBM opportunities
Fig. 7. Hubei Ammonia Plant mapped onto nearby oil fields. Zones: 50, 100, 150 km.
CO2 can be stored in beds of unminable coal and in some instances CO2-ECBM might be feasible. Though CO2ECBM is a much more embryonic technology than CO2EOR, China’s large coal resources have generated much CO2-ECBM interest. In 1999, a joint project was initiated between the Alberta Research Council (ARC) and the China United Coal Bed Methane Corporation (CUCBM) to address a number of issues that might lead to a CO2ECBM demonstration project in China. Though it is still in the development phase, the project aims to compile an inventory of suitable coal-beds for CO2-ECBM and perform micro-pilot and large-scale tests in China.
Fig. 8. Yuntianhua Chemical Group mapped onto nearby gas fields. Buffer zones: 50, 100, 150 km.
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Fig. 9. China’s ECBM regions. Source: Stevens and Kuuskraa (1998).
5. Conclusions
Fig. 10. China’s premier CO2-ECBM regions mapped in relation to identified CO2 sources.
China’s coal bed methane (CBM) potential is estimated to be one of the world’s largest—between 16,000 and 35,000 GNm3 (Zhang and Zhang, 1996). However, the CO2-ECBM potential is uncertain. Stevens and Kuuskraa (1998) identifies the Ordos Basin and the Northeast China Coal Region as regions with the greatest CO2-ECBM potential. These regions are shown in Fig. 9. The Ordos Basin has a coal-bed methane resource of 445 GNm3, a possible CO2-ECBM recovery potential of 180 GNm3 (about a 2 year natural gas supply at the average rate expected for China during 2001–2025), and a corresponding CO2 storage potential of 660 Mt CO2. The NE China Coal Region is estimated to have a coal-bed methane resource of 55 GNm3, a CO2-ECBM recovery potential of 5.5 GNm3, and a CO2 storage potential of 21 Mt CO2. Although prospective CO2 storage volumes at these two sites are trivial in relation to China’s CO2 emission rate (3322 Mt CO2 in 2002), CO2 storage demonstration projects might plausibly be associated with CO2-ECBM projects in these regions. Of the nine ammonia plants identified as potential CO2 sources for demonstration projects, the Weihe, Huainan and Nanjing ammonia plants are located closest to the Ordos and NE China coal-bearing regions (Fig. 10).
Relatively low-cost CO2 storage demonstration projects could be carried out at a number of sites in China where low-cost concentrated CO2 is available at coal-fed ammonia plants that are near underground sites where CO2 might be stored. Nine currently operating or planned ammonia plants were identified where the streams of essentially pure CO2 are available at annual flow rates between 570 and 1070 kt of CO2 per year. Based on these CO2 sources, four possible CO2 storage demonstration projects for storage in deep saline aquifers were identified. The costs for compressing, transporting and storing the CO2 for these projects ranged from $15 to $21/t of CO2, the corresponding total project costs range from $15 million to $18 million dollars per year, and the investment required per project ranges from $56 million to $71 million. Three possible CO2-EOR projects were identified for two oil fields, each with a CO2-EOR potential of about 30 MMBO and requiring about 16 Mt CO2. These CO2-EOR projects are likely to be economically attractive without subsidy at oil prices of the order of $30 a barrel or more. Before the CO2 storage demonstration opportunities identified in this paper can be implemented, in-depth, sitespecific studies are needed to corroborate and update the information presented here. Of the nine ammonia plants listed as potential CO2 sources, first-hand data was obtained only for the Nanjing Chemical Industry Plant. The CO2 emissions for the remaining eight plants were estimated based on published ammonia and urea production rates and the gasification process used. Furthermore, the data should be updated to reflect the ongoing shift from oil gasification to coal gasification; of the nine ammonia plants identified as potential CO2 sources for a CO2 storage demonstration project, only three plants currently use coal gasification technology. The other six ammonia plants (all of which are
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contracted to employ the Shell Coal Gasification Process) will begin operation on coal in the near future. Since ammonia production rates could be different once operation on coal begins, it is desirable to update the data provided here in order to take into account the latest developments in China’s ammonia industry. Site-specific analyses are also needed for the identified CO2 storage sites to better assess their suitability for demonstration projects. The analyses completed on CO2 storage are based on geological data obtained from a report published by China’s Petrolic Industry Press and was not corroborated by other sources nor by any geological surveying. Assessments at each of the three identified storage sites should aim to better understand geological properties, particularly the permeabilities of the oil and gas fields. Funding for CO2 storage demonstration projects in China would most likely come from some mix of government, multinational agency, and private company sources—with most of the needed funding coming from sources outside of China.
Successful CO2 capture and storage demonstrations in China and elsewhere could help pave the way for eventual widespread deployment of these technologies both in China and the rest of the world. Appendix A Properties of CO2 sources in China (see Table A1). Appendix B Properties of identified CO2 sources (see Table B1). Appendix C Physical characteristics and estimated costs for prospective CO2 capture and storage demonstration projects (see Table C1). Appendix D CO2-EOR production potential and associated CO2 storage potential (see Table D1).
Table A1 Name
Location
Gasifier
Status
Year
Main feed
] of operating/ spare gasifiers
Fuel input
Syngas capacity (Nm3/d)
Anhui Ammonia Plant (Sinopec)a
Anqing, Anhui
Shell
C
2006
Coal
1/0
2000 t/day
3,400,000
Dahua Chemical Industrial Corp.
Dalian, Liaoning
TexacoShell
Cb
2006b
Oil-coalb
1/0
1000 t/dayb
1,500,000b
Dong Ting Ammonia Plant (Sinopec-Shell)a
Yueyang, Hunan
Shell
C
2005
Coal
1/0
2000 t/day
3,400,000
Huainan Chemical General Works
Huainan, Anhui
Texaco
O
2000b
Coal
2/0
255 MWth
1,400,000
Hubei Ammonia Plant (Sinopec)a
Zhijiang, Hubei
Shell
C
2006
Coal
1/0b
2000 t/day
3,400,000
Inner Mongolia Fertilizer Co.
Hohhot, Inner Mongolia
Shell
O
1996
Vacuum residue
2/0
326 MWth
2,100,000
Jilin Chemical Industrial Corp.
Jilin, Jilin
Texaco
C
2000
Visbreaker residue
2/0
358 MWth
2,096,500
Jiujiang Petrochemical Co.
Juijiang, Jiangxi
Shell
O
1996
Vacuum residue
2/0
326 MWth
2,100,000
Lanzhou Chemical Industrial Co.
Lanzhou, Gansu
Shell
O
1998
Vacuum residue
2/0
350 MWth
2,100,000
Liuzhou Chemicala
Liuzhou, Guangxi
Shell
C
2005
Coal
1/0
1200 t/day
2,100,000
Lunan Chemical Co.
Tengzhou, Shandong
Texaco
O
1993
Bit. Coal
2/1b
1000 t/dayb
1,776,000b
Nanjing Chemical Industry Co.
Nanjing, Jiangsu
Texaco
Cb
2004b
Oil-coalb
2/1b
358 MWth
4,045,080b
Shuanghuan Chemicala
Yingcheng, Hubei
Shell
C
2004
Coal
1/0
900 t/day
1,300,000
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2377
Table A1 (continued ) Urumqi Chemical Plant
Urumqi, Xinjiang
Texaco
O
1985
Visbreaker residue, gasb
3/0
358 MWth
2,100,000
Weihe Fertilizer Co.
Weinan, Shaanxi
Texaco
O
1996
Coal
2/1
372 MWth
2,040,000
Yuntianhua Chemical Groupa
Shuifu, Yunnan
Shell
C
2006
Coal
1/0
2000 t/day
3,400,000
Yunzhanhua Chemicalsa
Qujing, Yunnan
Shell
C
2006
Coal
1/0
2000 t/day
3,400,000
Zhenhai Refining and Chemical Co.
Ningbo, Zhejiang
Texaco
O
1983
Visbreaker residue
3/0
350 MWth
2,100,000
C indicates plant currently under construction and O indicates plant currently in operation. a
Indicates new gasifier not included in DOE Gasification Database. Indicates an update from DOE World Gasification Database.
b
Table B1 Name
Location
Gasifier
Secondary product(s) (kt/y)
CO2 uses (kt CO2/y)
NH3 production (kt/y)
Gross CO2 (kt/y)
Total CO2 used (kt/y)
Net avail. CO2 (kt/y)
Anhui Ammonia Plant
Anqing, Anhui
Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Dong Ting Ammonia Plant
Yueyang, Hunan Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Huainan Chemical General Works
Huainan, Anhui
Texaco
Urea: 300 MeOH: 50 Urea: 219 NH4NO3: 110 MeOH: 69
360
1138
288
850
Hubei Ammonia Plant
Zhijiang, Hubei
Shell
Urea: 582
330
1297
428
869
Liuzhou Ammonia Plant
Liuzhou, Guangxi
Shell
Urea: 300 MeOH: 100 Urea: 220 NH4NO3: 180 MeOH: 37.5
300
1002
358
645
Nanjing Chemical Industry Co.
Nanjing, Jiangsu Texaco
Urea: 520 H2: oil refinery
Urea: 381.3 Dry ice: 40
300
1493
421
1071
Weihe Fertilizer Co. Weinan, Shaanxi Texaco
Urea: 520
Urea: 381.3
300
948
381
567
Yuntianhua Chemical Group
Shuifu, Yunnan
Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Yunzhanhua Chemicals
Qujing, Yunnan
Shell
Urea: 582
Urea: 427 Drinks: 0.067
330
1297
428
869
Urea: 427 Drinks: 0.067
Table C1 Project
NanjingZhenwu
CO2 vol. (kt/y)
1071
Avg API
38
Dist. (km)
120
Well depth Case (km)
2.71
Perm. (mD)
Max. injectivity (ton/day)
Mean K
1110
150,000
Min K
95
6600
# Wells
1
Costs for CO2 compression, transport, and storage
Cost component
Capital investment (million $)
Specific cost ($/t CO2)
Annual cost (million $/year)
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
16 42.7 58.7 5.5 0 64.2
6.4 8.9 15.3 1.1 0 16.4
17.6
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Table C1 (continued ) Dong TingWangchang
HubeiWangchang
YuntianhuaWeiyuan
869
869
869
24
24
N/A
115
145
85
2.61
2.61
3.24
1
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
13.9 38.2 52.1 5.3 0 57.4
6.7 9.4 16.1 1.4 0 17.4
15.1
1
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
13.9 40.4 54.3 5.3 0 59.6
6.7 12.5 19.2 1.4 0 20.5
17.8
21,000
1
3
13.9 35.6 49.5 6.3 0 55.7 13.9 35.6 49.5 18.9 2.5 70.9
6.7 6.4 13.1 1.6 0 14.7 6.7 6.4 13.1 4.8 0.6 18.6
12.8
1100
CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total CO2 compression CO2 transport Subtotal CO2 disposal wells Surface facilities Total
Mean K
1300
53,000
Min K
75
3000
Mean K
1300
53,000
Min K
75
3000
Mean K
20
Min K
1
Table D1 Basin
Subei
Jianghan
Field Depth (m) Thickness (m) Avg. API URR (MMBO) OOIP (MMBO) EOR (MMBO) Total CO2 (Mt)
Zhenwu 2710 17 38 136 316 34 16.3
Wangchang 2610 10 24 217 750 29.8 16.7
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