Page 148 - Materials Chemistry, Second Edition

9 Life Cycle Inventory Analysis 133

Figure 9.5 presents a decision tree for identifying product substitutes.
As an additional consideration, it should be noted that in some cases one product
will not substitute another directly. For example, the production of biodiesel leads
to the co-production of glycerol which contains salts and other impurities. Before it

Find the most significant users of the product
through market analyses. Go through the
following procedure for each of the users.

Does the product have the necessary properties
to be considered a substitute by the user?
Consider where relevant functionality, technical
quality, costs, additional services, aesthetics,
image, and health - and environmental
properties.
The product is not a
No
Yes substitute. Identify
alternative product
Is the production of the potential substitute
constrained?
• Is it produced as a low-value by-product?
• Is its availability constrained by regulation?
• Is its availability physically constrained?
• …

No
Yes
The product is a
substitute.
Will the demand for the potential substitute
Remember to
increase or decrease as result of decision?
consider whether
there may be
Decrease
Increase other alternatives.
Then, go to Step
4 to find the
Is the potential substitute already used to the
production
extent the constraint allows?
technology
No affected.
Yes
The product is not a substitute. Identify
alternative product

Fig. 9.5 Procedure for identifying possible substitutions of products as consequence of changes
in supply or demand