Environmental and Economic
Implications of Phasing Out Solid
Fuels Used for Cooking in China
Eric D. Larson
Research Engineer/Associated Faculty
Princeton Environmental Institute
Princeton University, USA
Mitigation of Air Pollution and Climate Change in China
17-19 October 2004
Oslo: Norwegian Academy of Science and Letters
Outline
•
•
•
•
•
Indoor air pollution
Global warming
Challenge of replacing solid cooking fuels
Prospects for increasing LPG use
Prospects for dimethyl ether (DME)
Pollution from Cooking Stoves/Fuels
(measured emissions to room air from flue-less stoves in China)
50.0
45.0
PIC = Products of Incomplete Combustion
PIC to air (grams/MJ of heat to pot)
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
Town gas
Natural gas
LPG
Kerosene
(wick stove)
Coal
Honeycomb
briquettes
coal (metal,
(metal stove) improved)
Honeycomb Coal powder
Fuelwood
Brushwood
coal (metal (metal stove) (Indian metal (Indian metal
stove)
stove)
stove)
Source: Zhang, J., Smith, K.R., et al., 2000, “Greenhouse gases and other airborne pollutants from household stoves in China: a database for emission
factors,” Atmos. Environ. 34: 4537-4549.
Approximate Total
Global Human
Exposure to
Particulate Air
Pollution
As cited by Reddy, Williams, Johansson, 1997, Energy After Rio, UNDP, New York.
Global Warming Potentials of
Combustion Products (relative to CO2)
Source: Bond, Venkataraman, and Masera, 2004, “Global atmospheric impacts of residential fuels,” Energy for Sustainable Development, VIII(3): 115-126
Global Warming Commitment of
Cooking Fuels/Technologies (estimates)
20-year GWP
100-year GWP
(cooling impact)
(from biomass, if
biomass obtained
by deforestation)
global warming commitment, kg CO2-equivalent per GJ delivered to pot
Source: Bond, Venkataraman, and Masera, 2004, “Global atmospheric impacts of residential fuels,” Energy for Sustainable Development, VIII(3): 115-126
Indicative Change in Radiative Impact
Compared with Traditional Fuels
Averages taken from previous GWC estimates: Traditional stoves = average of 3 “traditional” cases; Improved stoves = average of 3 “improved” cases;
Charcoal = average of 2 “charcoal” cases; Clean fossil fuels = average of kerosene, LPG, and natural gas.
Source: Bond, Venkataraman, and Masera, 2004, “Global atmospheric impacts of residential fuels,” Energy for Sustainable Development, VIII(3): 115-126
“Solving” the Problem
Pollution from Cooking Stoves/Fuels
(measured emissions to room air from flue-less stoves in China)
50.0
45.0
PIC = Products of Incomplete Combustion
PIC to air (grams/MJ of heat to pot)
40.0
35.0
30.0
25.0
20.0
15.0
10.0
5.0
0.0
Town gas
Natural gas
LPG
Kerosene
(wick stove)
Coal
Honeycomb
briquettes
coal (metal,
(metal stove) improved)
Honeycomb Coal powder
Fuelwood
Brushwood
coal (metal (metal stove) (Indian metal (Indian metal
stove)
stove)
stove)
Source: Zhang, J., Smith, K.R., et al., 2000, “Greenhouse gases and other airborne pollutants from household stoves in China: a database for emission
factors,” Atmos. Environ. 34: 4537-4549.
Efficiencies of Cooking Stoves/Fuels
(from standardized meal cooking tests)
Source: Dutt, G. S., and N. H. Ravindranath, 1993, “Bioenergy: direct applications in cooking,” Renewable Energy, H. Kelly, T.B. Johansson, A.K.N.
Reddy, and R.H. Williams (eds.), Island Press, Washington, DC, pp. 653-697.
How “easily” can the dirty cooking
problem be solved?
• Goldemberg et al. (2004) indicate that 2.6 billion
people cook with solid fuels today worldwide. They
estimate 35 kg/capita/year of LPG (liquefied
petroleum gas) could meet basic cooking needs.
• 35 kg LPG x 46 MJ/kg = 1.61 GJ/year/cap.
• 1.61 GJ/yr/cap x 2.6 billion = 4.2 billion GJ/year (or
100 million toe, 143 million tce).
• This is 1% of global commercial energy use in 2003.
• The corresponding figure for China is 2.6%.
What is the value of
clean cooking fuel?
Coal, Biomass
WB* has estimated rural indoor air
pollution costs $4 - $11 billion/year.
This is $22 - $63/GJ of fuel required.
Retail price of LPG in rural China is
50-60 Yuan RMB for a 15 kg bottle.
(US$8.8 to $10.6/GJ).
* Johnson, Liu, Newfarmer, Clear Water, Blue Skies, China’s Environment in the New Century, World Bank, 1997.
LPG
Producer Gas
Barriers to Cleaner Cooking
• “Natural” progression up the “energy ladder” (dung/crop residues 
fuelwood  charcoal  kerosene  LPG  NG/electricity) follows
increasing incomes – very slow process.
• Low/zero private cost for biomass/coal use. External costs (e.g., health
damages) not reflected in private price of solid fuels, so difficult to
compete with cleaner fuels that carry higher private cost.
• Cooking is women’s domain, but women are not generally the decision
makers regarding cooking fuels.
• Dirty fuels are not politically consequential. (In recent Indian elections,
roads, water, and electricity were swing issues. Cooking fuel was not.)
• Governments of industrialized countries may not appreciate the links
between dirty fuels in developing countries and impacts on their own
countries.
• Most energy-related development assistance over the past 30 years has
focused on electrification, and this continues to be the case.
• Where heating is done with solid fuels, adopting clean cooking fuel
will only partially improve the situation.
Fuel Options for
Cleaner Cooking in China
• Fossil-derived fuels
–
–
–
–
–
–
Liquefied petroleum gas, LPG
Town gas (gasified coal)
Natural gas
Kerosene
Dimethyl ether (from coal)
Electricity
• Biomass-derived fuels
–
–
–
–
–
Producer gas
Biogas
Dimethyl ether
Ethanol/ethanol gel
Electricity
LPG Use in Developing Countries
14000
LPG CONSUMPTION IN 1999
(Top 20 Developing Country Consumers)
12000
1000 t
kg per capita
8000
6000
4000
2000
Source: Annual Statistical Review of LP Gas, LP Gas Association, Paris.
ol
om
bi
a
C
si
a
In
do
ne
hi
le
C
pi
ne
s
Ph
ilip
cc
o
or
o
M
Ta
iw
an
q
Ira
in
a
en
t
Ar
g
ys
ia
M
al
a
er
ia
Al
g
Th
ai
la
nd
n
Ira
Eg
yp
t
ia
ra
b
ez
ue
la
Ve
n
a
di
A
Sa
u
Ko
r
th
So
u
In
di
ea
zi
l
Br
a
M
ex
ic
o
hi
na
0
C
Total Consumption (1000 t)
10000
China’s LPG Sources
16000
CHINA LPG SOURCES
Average annual consumption growth of 15.7% per year, 1995-2001
14000
Imported
Domestic Production
12000
(including some from imported crude oil)
1000 t
10000
8000
Supplying 800 million people with 35 kg/cap/yr
of LPG would require 28 million tons of LPG
(double current consumption). Much of the
additional supply would need to be imported.
6000
4000
2000
0
1990
1991
1992
1993
1994
Source: Annual Statistical Review of LP Gas, LP Gas Association, Paris.
1995
1996
1997
1998
1999
2000
2001
中国原油和油品进口增长情况
Chinese Oil Imports since 1988
100
90
其它国家 Others
前苏联 FSU
80
苏丹 Sudan
60
50
Crude oil
原油
35
30
安哥拉 Angola
越南 Vietnam
印度尼西亚 Indonesia
苏丹 Yemen
阿曼 Oman
40
沙特阿拉伯 Saudi Arabia
30
伊朗 Iran
Refined products/LPG
油品和液化气
液化气 LPG
其它 Other Products
百万吨 Mln t
百 万 吨 Mln t
70
40
25
20
石脑油 Naphtha
汽油 Gasoline
航空煤油 Jet
柴油 Gas oil
燃料油 Fuel oil
15
10
20
5
10
0
1988
0
1993
1998
Source: Tony Cui (BP China), personal communication, July 2004.
2003
1988
1993
1998
2003
液化气与原油价格比较
LPG and Crude Oil Prices
350
原油 Crude oil
30
300
沙特丙烷 Saudi CP
25
250
预计
Proj
20
200
15
150
10
100
5
50
1988
1990
1992
1994
Source: Tony Cui (BP China), personal communication, July 2004.
1996
1998
2000
2002
2004
丙烷 , 美元 / 吨 Propane, USD/t
油价 , 美元 /桶 Oil, USD/bbl
35
DME (CH3OCH3) is Similar to LPG
• DME used today as ozone-safe aerosol propellant. Current global production is
~150,000 tons/year (from methanol).
• DME is also a good diesel-engine fuel: high cetane #, no sulfur, no C-C bonds
so no soot, lower NOx emissions.
• New DME manufacturing capacity under construction/planned:
– From nat. gas: 110,000 t/y (Sichuan, China, 2005 on-line); 800,000 t/y (Iran, 2006 on-line)
– From coal: 840,000 t/y project approved (Ningxia, China, construction not yet started)
Making DME from Coal
• Gasify coal in O2/H2O to produce synthesis gas “syngas” (mostly CO, H2).
• Increase H/C ratio (from ~0.8 for coal to ~ 3 for DME) via water gas shift
reaction (CO + H2O  H2 + CO2).
• Remove acid gases (H2S and CO2) from syngas.
• Convert syngas to DME in a slurry-phase synthesis reactor.
• Separate DME product from unconverted syngas.
• Produce exportable electricity with unconverted syngas.
Source: Larson and Yang, 2004, “Dimethyl Ether (DME) from Coal as a Household Cooking Fuel in China,” Energy for Sustainable Development, VIII(3): 115-126
Growing Global Gasification Capacity
Will Reach 61 GWth in 2004
In 2004
By activity:
• 24 GWth chemicals
• 23 GWth power
• 14 GWth synfuels
By region:
•
9 GWth China
• 10 GWth N America
• 19 GWth W Europe
• 23 GWth Rest of world
By feedstock:
• 27 GWth pet. residuals
• 27 GWth coal
•
6 GWth natural gas
•
1 GWth biomass
Source: Dale Simbeck, SFA Pacific Inc., Mountain View, California.
Slurry-Phase Synthesis of Liquids
• Basic overall reactions:
CO + 2H
2
 - CH - + H O
2
2
Fischer-Tropsch liquids
Liquid-phase reactors
have much higher one3CO + 3H  CH OCH + CO2
Dimethyl ether
2
3
3
pass conversion of
CO+H2 to liquids than
traditional gas-phase
CO + 2 H  CH OH
Methanol
reactors, e.g., liquid2
3
phase Fischer-Tropsch
synthesis has ~80%
Fuel product
(vapor)
one-pass conversion,
(vapor)
CO + 2H  - C HFuel
- + product
HO
Fischer-Tropsch
liquids
2
2+ unreacted
2+ unreacted
syngas
syngas
compared to <40% for
Fischer3CO + 3H  CH OCH + CO2Disengagement
Dimethyl
ether technology.
traditional
2
3 Disengagement
3
Tropsch MeOH DME
zone
• Commercial status:
Commercial
units in operation
CO + 2 H

Demonstrated at
commercial scale
Steam
Catalyst
powder
slurried
in oil

TYPICAL CONDITIONS:
zone
 CH OH
2 Steam 3
Catalyst
powder
slurried
in oil
CO
Cooling water

Synthesis gas
(CO + H2)
China, Japan, USA
Synthesis gas
(CO + H2)
o
oC
= 200-300 C
T =T 200-300
CO
Cooling water
Demonstrated at
pilot-plant scale
TYPICAL REACTION CONDITIONS:
Methanol
P =P 25-100
atm.
= 50-100 atmospheres
catalyst
H2
H2
catalyst
CH3OCH3
CH3OH
CH3OCHC3nH2n+2
CH3OH (depending
CnH2n+2 on catalyst)
(depending
on catalyst)
Energy Balance for DME from Coal
clean syngas
water
Rectisol
Grinding,
Slurrying
coal
synthesis
product
syngas bypass
O2 (95%)
vent
Recycle
Compressor
Cooler
Gasifier
1390°C
75 bar
Oxygen
Production
Syngas
Pre-heater
boiler feed
water
Sour
WGS
CO2 H2S
Cooler
Liquid Phase
Synthesis
Reactor
scrubber
water
quench
water
air
Quench
quenched
gas
Scrubber
MP steam
steam
Bituminous coal typical of
Yanzhou area, Shandong
Province (dry weight %)
C
LP Steam
unconverted
syngas
to stack
63.7
H
4.3
O
6.8
S
4.0
N
1.1
Ash
20.2
Moisture (as rec’d)
7.1
HHV (MJ/kg as rec’d)
24.54
LHV (MJ/kg, as rec’d)
23.49
Flash
Expander
~
Flash
cond.
Boiler
~
Gas Turbine air
liquid
~
Steam
turbine
DME
Distillation
Energy Balance Summary*
Coal feed (MW)
2203
DME (MW)
600
Net electricity (MW)
490
methanol
* Source: “VENT” case in Celik, F. Larson, E.D., and Williams, R.H., 2004, “Transportation Fuel from Coal with Low CO 2 Emissions,” Proceedings of the 7th
International Conference on Greenhouse Gas Control Technologies, held Sept. 2004 (proceedings forthcoming).
Estimated Retail Cost/Price of
DME from Coal in China
Source: Larson and Yang, 2004, “Dimethyl Ether (DME) from Coal as a Household Cooking Fuel in China,” Energy for Sustainable Development, VIII(3): 115-126
LPG, DME Retail Price Comparisons
Windfall
profits
potential
Source: Larson and Yang, 2004, “Dimethyl Ether (DME) from Coal as a Household Cooking Fuel in China,” Energy for Sustainable Development, VIII(3): 115-126
Summary/Conclusions
• Environmental/health problems associated with cooking/heating
with solid fuels are significant in China.
• From a societal perspective, the cooking problem can be solved
cost-effectively and without significant global energy impacts.
• Major institutional, financial, political, social, and other barriers
exist, however. (I have not addressed these in this talk!)
• LPG is attractive for China, but concerns over energy security and
crude-oil linked price may limit future expansion potential.
• DME from coal (with co-production of electricity) is an attractive
additional option.
– DME could be made in large quantities in many areas of China, including
in some of the poorest Western provinces.
– Low costs compared to prospective future LPG prices.
– Total coal use for cooking and electricity could be reduced by about 25%
compared to cooking directly with solid coal and generating the electricity
from a stand-alone coal-IGCC power plant.
– CO2 capture and storage during DME production may be long term option.