Page 178 - Materials Chemistry, Second Edition

9 Life Cycle Inventory Analysis 163

demand for methanol. We therefore again start in Step 1 by asking the question:
“What happens when I increase the demand for methanol?” As this is a demand
oriented question, we go to Step 2. Here we are first asked whether methanol can be
produced without constraints. As this is the case, we go to Step 4. Here we are
asked to consider the overall trend in the market, the scope of the decision in
comparison to the overall market for methanol, and whether the decision leads to an
increase or decrease in demand. Through market studies we find that the trend in the
market, which can be considered global, is an increasing production. Secondly, the
size of the decision, which in this case is to produce a few hundred extra tonnes of
poultry fat biodiesel will amount to very little compared to the overall market
volume for methanol. We should therefore identify the short-term marginal
producer.
Given that our decision leads to an increase in demand, we are told by Table 9.1,
that the methanol will be produced by the least competitive producer on the market.
As there are more or less only producers making methanol from synthetic gas, we
assume that the methanol will be produced using this technology.
Other inputs and outputs to and from the biodiesel process are handled in a
similar way, but to keep the example relatively short, these will not be discussed
here.
As the example shows, creating a consequential LCI is in many cases a rather
laborious task as detailed knowledge is needed about the markets affected by the
decision, as for example establishing knowledge about potential substitutes for
poultry fat in the feed industry in the example above. Much of the time spent
making the LCA will therefore often be used in preparing the consequential LCI.

References

This chapter is to a large extent based on the ILCD handbook and the ISO standard 14040 and
14044. Due to the scope of this chapter, some details have been omitted, and some procedures
have been rephrased to to make the text more relevant to students. For more details, the reader
may refer to these texts:
EC-JRC: European Commission—Joint Research Centre—Institute for Environment and
Sustainability: International Reference Life Cycle Data System (ILCD) Handbook—General
guide for Life Cycle Assessment—Detailed guidance, 1st edn. March 2010. EUR 24708 EN.
Luxembourg, Publications Office of the European Union (2010)
ISO: Environmental Management—Life Cycle Assessment—Principles and Framework (ISO
14040). ISO, the International Organization for Standardization, Geneva (2006a)
ISO: Environmental Management—Life Cycle Assessment—Requirements and Guidelines (ISO
14044). ISO, the International Organization for Standardization, Geneva (2006b)

Additional References Used in the Text

Birkved, M., Hauschild, M.Z.: PestLCI—a model for estimating field emissions of pesticides in
agricultural LCA. Ecol. Model. 198, 433–451 (2006). doi:10.1016/j.ecolmodel.2006.05.035