We want to make sure that the environmental benefit of producing this homegrown ethanol is not overshadowed by all of the activities needed to produce the ethanol.

Research question

Our role in this project is to serve as a sort of “environmental consultant” to the other projects.  We want to calculate how much energy is used, and how many greenhouse gasses are emitted, in all of the activities involved in the growth, harvest, and transport of all of the biomass to be used by Frontier Renewable Resources to produce cellulosic ethanol. We want to make sure that the environmental benefit of producing this homegrown ethanol is not overshadowed by all of the activities needed to produce the ethanol – otherwise, it wouldn’t make sense to operate the facility. Other work in the literature has shown that cellulosic ethanol does reduce greenhouse gas emissions compared to an equivalent amount of fossil fuel, but we want to compile data specific to this project to have concrete proof that this project is making a significant environmental improvement.

Approach

We performed a life cycle assessment of the forest feedstock supply chain to support ethanol production at the Kinross facility, taking into account all activities involved in the growth, harvest, and transport of woody biomass. Fossil fuel emissions and energy use for each activity were compiled, using national databases, peer-reviewed journals relevant to our situation, and local data from foresters, loggers, and truckers where possible. All of this data are related to one consistent unit – one ton of green timber delivered to the plant gate – in order to standardize all of the contributions from forestry operations, transportation, and other inputs.

Progress and Results

An initial estimate of the greenhouse gas emissions and energy inputs for the major activities involved with supplying roundwood timber to the facility in Kinross, MI was provided to researchers, who have incorporated this data into their models. We will update our estimates as new data from local loggers and log truck drivers becomes available.

Results indicated that a full processor/forwarder is the best choice of harvesting equipment configuration due to relatively low inputs and high reported productivity, although the burdens of harvesting depend strongly on the intensity of harvest being conducted. Multimodal truck + rail transport had roughly 3-fold lower environmental burdens than typical log truck transport, which was directly related to the increased fuel efficiency of rail transport. A typical supply chain for forest biomass in northern Michigan would have environmental impacts similar to forest biomass supply chain operations
in other regions, in comparison with other reported studies.

Final Project Report:

Life Cycle Environmental Impacts of Forest Biomass Supply Chains