LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 6A: TOOLS AND DATABASES 8 th glyphosate Oxygen Air (untreated)
Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
1,000 199 199
DSIDA in 37pct
Natural gas
PMIDA sol diethanol amine Ammonia Natural gas (unprocessed)
1,422 1,186 765 169 34.9
nitrogen from
35.6
air Air (untreated)
65.1 65.1
oxygen from air Air (untreated)
28.9 28.9
Water for rxn Water (untreated)
45.2 45.2
Ethylene oxide Ethylene Naphtha
oil (in
ground)
603 452 461 467
Oxygen Air (untreated)
442 443
oxygen from air Air (untreated)
497 497
sodium chloride in salt rock, in
Sodium hydroxide brine 26 wtpct ground
612 495 495
Water for rxn Water (untreated)
145 145
Formaldehyde Methanol Natural gas
Natural gas
(unprocessed)
263 330 170 173
oxygen from air Air (untreated)
170 170
Water for rxn Water (untreated)
303 303
oxygen from air Air (untreated)
186 186
Phosphorus
sodium chloride in salt rock, in
trichloride Chlorine
brine 26 wtpct ground
1,024 808 654 654
Water for rxn Water (untreated)
191 191
phosphorus, white coke, metallurgical coal mass coal (in ground)
235 22.1 25.7 25.7
oxygen Air
Sulfuric acid Sulfur trioxide from air (untreated)
0.115 0.0934 0.0580 0.0580
oil (in
Sulfur ground)
0.0403 0.0415
Water for Water
rxn (untreated)
3.52E-03
Water
3.52E-03
Water for rxn (untreated)
phosphate ore, in
0.0234 0.0234
Phosphate rock ground
157 547
Silica silica (untreated)
62.3 62.3
Sodium sodium chloride in
hydroxide brine 26 wtpct salt rock, in ground
242 196 196
Water for rxn Water (untreated)
57.2 57.2
Water for rxn Water (untreated)
264 264
Figure 1. Supply chain for production of glyphosate from commodity chemicals
Process energy consumption includes all inputs of heat and electricity. This includes heat inputs from
steam, Dowtherm, direct combustion of fuel, electricity or other sources. During cradle-to-gate (ctg) production
of electricity, steam, etc., fuels are combusted, resulting in an inventory of energy emissions and fuel
consumption. The ctg energy value of the fuels used (fuels in making energy plus precombustion fuel to
deliver fuel to point of energy production) is the natural resource energy (nre). The sum of the nre and the
energy value of the feedstocks used to build the glyphosate molecule (right-most components in Fig. 1) is
comparable to the cumulative energy demand LCA metric.
The process and natural resource energies are good proxies for the environmental impact inherent in production
of materials. Table 2 shows the mass of each product used to produced 1000 kg of glyphosate. For
each material, the mass of byproducts and the allocation parameter are shown. For example, for each kg of
ammonia produced 1.18 kg of CO2 are produced. For mass allocation, the gtg energies, inputs, and emissions
are multiplied by 1 / 2.18 = 0.459. For each kg of ammonia produced, 12.6 MJ of process energy are
used. Of this, 12.6*.459 = 5.8 MJ are allocated to ammonia. In the supply chain for 1000 glyphosate, 169
kg of ammonia are used. Thus, 976 MJ of process energy are used.
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