34
H. Li et al.
E sum,i = C sum,i + p sum,i
(1)
In formula 1, E sum, i is the total CO 2 emissions from the process i; C sum, i is the
combustion emission of the process i; P sum, i is the technical emission of the process
i.
In addition, CO 2 emission intensity is also an important indicator for analyzing
and evaluating CO 2 emissions in iron and steel enterprises. Emission intensity can
be calculated with formula 2 shown as follows:
e C O 2 ,i =
E sum,i
P
(2)
In formula 2, the e C O 2 ,i is the CO 2 emission intensity (kgCO 2 /t steel) of process
i; P is the steel output.
Determination of Emission Factors
Most of the emission factors are selected from the “Greenhouse gas emission
accounting and reporting requirements [11].” The carbon emission factor of
purchased electricity is affected by the provincial power grid in which the purchased
electricity is located [12], which can be selected according to the location of the
target enterprise. The emission factor of self-powered electricity can be calculated
based on the CO 2 emission in the self-owned power generation system. All the CO 2
emission factors are shown in Table 2.
Table 2 CO 2 emission factors
Type
Carrier
Emission Factor Unit
Process emission factor
Limestone
0.440
tCO 2 /t
Dolomite
0.471
tCO 2 /t
Hot metal a
E F hotmetal
tCO 2 /t
Liquid steel a
E F liquidsteel
tCO 2 /t
BFG/COG/LDG a
E FT gas
tCO 2 /10,000 Nm 3
Purchased electricity
E F D pe
tCO 2 /10,000 kWh
Self-powered electricity E F D sg
tCO 2 /10,000 kWh
Combustion emission factor Bitumite
1.747
tCO 2 /t
Anthracite
1.924
tCO 2 /t
Cleaned coal
2.208
tCO 2 /t
Coke/coke powder
2.862
tCO 2 /t
Natural gas
5.897
tCO 2 /t
BFG/COG/LDG a
E FC gas
tCO 2 /10,000 Nm 3