154 Introduction to Renewable Biomaterials
In this equation, the percent carbon in the material, for instance, piece of loblolly
pine with a carbon content of∼50%, can be multiplied by both the mass of the material
and the molecular weight of CO 2 then divided by the molecular weight of carbon. This
calculation can determine the CO 2 taken in from the atmosphere during growth and
the potential for the material to release CO 2 to the environment during decomposition.
There are different methods that can be used to track both biogenic and anthropogenic
carbon. Some studies do not track biogenic carbon as they assume that biogenic CO 2
is “carbon neutral” meaning has no effect on global climate change. This standpoint is
controversial and is not as transparent as tracking the uptake and the later potential
releases. Tracking biogenic carbon can add additional work, however, is more a more
robust method and provides additional transparency.
Secondary Data Data that are not directly collected from measurement within the
studies systems are often referred to as secondary data. Secondary data are often col-
lected from LCI databases, literature, or other previous studies. A useful LCI database
is provided by the National Renewable Energy Laboratory, the US LCI, available on the
web (http://www.nrel.gov/lci/).
The use of secondary data are often required in studies; however, there are often
discrepancies between the studied system and the system the secondary data describe.
One of the most common discrepancies is the location of production. For instance,
an LCI secondary data point from a database may describe loblolly pine production
in Georgia; however, the studied product is in reality made in North Carolina. The
data do not describe the system under study, however, could be representative of tree
growth in North Carolina. When secondary data are used, it is important to document
the differences in regionality, technology used in production, and other characteristics
that would result in secondary data not accurately representing the process of interest
in context of the studied LCI. In reality, secondary data can be as good as primary
data, as secondary data are at some point primary data of another study. Reusing other
study data within your own study is unavoidable in many cases, as time and funding
constraints often limit the time spent on data collection. Additionally, there are times
when collecting data on processes is just not feasible for other various reasons.
LCA Software There are many tools to assist an analyst in performing LCAs. There are
software and data packages specifically designed for performing LCAs, and tools made
in other software focused on certain aspects of LCA. No matter the form of the software,
the use of some sort of LCA software and data management system is nearly needed
in all LCAs. The LCI step of an LCA often requires a large data set listing hundreds
of emissions to the environment. Keeping track of these flows manually would be too
arduous, and LCA software is designed to manage these flows and perform specific
functions such as impact assessments based on the inventory as well as uncertainty
analysis. In this section, we discuss common LCA software as well as several LCA tools
which hopes help the reader find the best software and tools for their specific needs.
There is a large list of LCA software emerging onto the market all with various selling
features. This review is not exhaustive to all LCA software, and no preference is given
any software provider. What is learned about the reviewed software packages can also
be helpful in understanding how other tools and software work as well. A basic overview
of how data and LCA software will first be provided then a list of software packages.
