FULL FUEL CYCLE ASSESSMENT WELL TO TANK ENERGY INPUTS, EMISSIONS, AND WATER IMPACTS

Posted by Chlela Rita
Type: 
Full LCA available on the web
Comparative: 
yes
Publication year: 
2007
Language: 
English
Code: 
Vehicles/Fuels
Product: 
The alternative fuels considered include gasoline and diesel baselines compared to liquefied petroleum gas (LPG), natural gas, hydrogen, ethanol, biodiesel, synthetic diesel, and electricity.
Quality and sources
Is the study a: 
Detailed LCA
Was a critical review performed?: 
No
Is the study compliant with ISO 14044?: 
No
Sponsor name(s): 
TIAX LLC
Sponsor name(s): 
the California Energy Commission
Sponsor name(s): 
California Air Resources Board
Sponsor type: 
Company
Practitioner(s): 
Stefan Unnasch
Practitioner(s): 
Jennifer Pont
Practitioner(s) type: 
Consultant
Summary
Functional unit: 
Vehicle driven on a distance of 1 mile
Goal and scope of the summary: 
the economic and environmental impacts of technology and alternative fuel options that could reduce California’s dependence on petroleum as a transportation fuel. The agencies concluded that not only could on-road Gasoline and diesel consumption be reduced to 15 percent below 2003 levels by 2015 it could be done with net cost benefits. The agencies recommended that the reduction goal be achieved by doubling the federal fuel economy standard for new vehicles, and increasing the use of non-petroleum fuels to 20 percent of on-road demand by 2020.



The energy inputs and GHG
emissions correspond to the conversion efficiency and carbon intensity of
fuels. The results of this study are consistent with others in terms of
tracking the impacts of energy use. The key conclusions regarding GHG emissions
are:

1. GHG emissions from fossil
fuels depend on both the carbon content of the fuel and process energy inputs.
For fossil fuels, GHG factors (carbon in fuel + WTT) ranked from highest to
lowest on a MJ basis (without taking vehicle efficiency into account) are:

-Synthetic fuels from coal
without CO2 sequestration

-Hydrogen from on-site natural
gas reforming

-RFG with 5.7 percent ethanol

-E10

-FT diesel from natural gas
without use of process waste heat

-California ULSD, FTD with
waste heat utilization, DME, methanol

-LNG with modern boil off
management practices

-LPG from petroleum or natural
gas

-CNG

-Synthetic fuels from coal
with CO2 sequestration

2. A wide range of GHG factors
are achieved for various hydrogen and electric generation pathways. An electric
generation mix based on natural gas combined cycle power combined with
California’s RPS constraint is an appropriate mix for electric transportation
and the electricity inputs for fuel production. The use of renewable power
allows for the mitigation of GHG emissions, which is an option for all fuel
providers.

3. GHG emissions from biofuels
depend on agricultural inputs, allocation to byproducts, and the level and
carbon intensity of process energy inputs. For biofuels, GHG factors (carbon in
fuel + WTT) ranked from highest to lowest on a MJ basis (without taking vehicle
efficiency into account) are:

-Ethanol from corn with coal
fired boiler

-Ethanol from corn with
natural gas fired boiler

-Ethanol from corn with
reduced energy input by providing wet DDGS byproduct

-Soybean based biodiesel
(depending on N2O emissions and byproduct credits)

-Ethanol from cellulose and
sugar cane with no fossil fuel input for fuel production

-Ethanol from waste materials

The GHG emissions for biofuels
depend on many other factors. Most important are changes in land use that vary
with substantially with scenario assumptions. The analysis here provides the
WTT process inputs. Impacts associated with changes in land use can be added to
these values. Land use issues for a modest growth in U.S. based crops are
likely to replace other crops rather than expand agricultural areas. To the
extent that this assumption holds true, the impact of land use from U.S. crops
is a small portion of the WTT impact. The issue of deforestation needs to be
examined with several biofuel options. In the case of Brazilian ethanol, the
sugar cane is not grown in the Amazon, however second order agricultural
impacts should be documented.

Material impact(s): 
Global warming
Raw material impact level: 
High
Shipping impact(s): 
Global warming
Shipping impact level: 
Medium
Usage impact(s): 
Global warming
Usage impact level: 
High

This is a very interesting

This is a very interesting LCA. And the most important part is being able to study the environmental impacts of the different fuels studies in a new different perspective, the american one.


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