The functional unit selected is 1 GJ of bioenergy produced from
treating dairy waste, produced during 45 days, which was the
duration of completing a scenario. Results obtained from the study,
nonrenewable primary energy requirement (GJ) and GHG emission
(kg CO2 eq.) were expressed with respect to unit of bioenergy produced.
The geographical location is the US and the simulation was
carried out for 1 year. Details about the system boundary are given
in Fig. 1.
The nonrenewable primary energy requirement (NRPER), which
is a ratio of nonrenewable primary energy demand (GJ) to the
bioenergy (GJ) generated, was used as an indicator for energy effi-
ciency. Greenhouse gas produced (kg CO2 eq. per GJ of bioenergy produced) was used as an indicator for greenhouse gas emissions
or intensity. No allocation of energy or GHG was applied for the
sludge, biochar (case A and B). All impacts were allocated for
bioenergy production. Nutrients present in the sludge and manure
were taken into consideration for substituting the inorganic nutrients
through the system expansion approach (case A scenarios).
Due to negligible contribution of N, and P for plant growth from
biochar, nutrient value of biochar was ignored for the case A scenarios
[31].
N20 produced from the applied sludge/biochar (1.3% of the
applied nitrogen present in the sludge or manure) were taken into
consideration for the GHG calculation [30,32]. CH4 emission was
found to be negligible and also depends on the soil condition (submerged
or anaerobic condition induces CH4 production) and has
not been taken into consideration for GHG calculation [32]. For
case B scenarios, carbon sequestration from applied
sludge/biomass, biochar was only considered. Nutrients values of
sludge/biomass were ignored and therefore, associated N20 emission
from the applied land was also ignored.
The functional unit selected is 1 GJ of bioenergy produced fromtreating dairy waste, produced during 45 days, which was theduration of completing a scenario. Results obtained from the study,nonrenewable primary energy requirement (GJ) and GHG emission(kg CO2 eq.) were expressed with respect to unit of bioenergy produced.The geographical location is the US and the simulation wascarried out for 1 year. Details about the system boundary are givenin Fig. 1.The nonrenewable primary energy requirement (NRPER), whichis a ratio of nonrenewable primary energy demand (GJ) to thebioenergy (GJ) generated, was used as an indicator for energy effi-ciency. Greenhouse gas produced (kg CO2 eq. per GJ of bioenergy produced) was used as an indicator for greenhouse gas emissionsor intensity. No allocation of energy or GHG was applied for thesludge, biochar (case A and B). All impacts were allocated forbioenergy production. Nutrients present in the sludge and manurewere taken into consideration for substituting the inorganic nutrientsthrough the system expansion approach (case A scenarios).Due to negligible contribution of N, and P for plant growth frombiochar, nutrient value of biochar was ignored for the case A scenarios[31].N20 produced from the applied sludge/biochar (1.3% of theapplied nitrogen present in the sludge or manure) were taken intoconsideration for the GHG calculation [30,32]. CH4 emission wasfound to be negligible and also depends on the soil condition (submergedor anaerobic condition induces CH4 production) and hasnot been taken into consideration for GHG calculation [32]. Forcase B scenarios, carbon sequestration from appliedsludge/biomass, biochar was only considered. Nutrients values ofsludge/biomass were ignored and therefore, associated N20 emissionfrom the applied land was also ignored.
การแปล กรุณารอสักครู่..
