Fall 2015 Page 1

MIE1715H: Life Cycle Engineering Exercise 1: Due: October 5, 2015 1. Find one example of a product where the largest or most detrimental environmental impact persumably derived from each of the following: Raw Material Acquisition Production Consumption Disposal

2. In the example below only the outputs of products are displayed for the sake of simplicity. Functional unit can be based on inputs as well as outputs. The goal of the study is to compare plywood box with other packaging options (e.g., carton box, plastic box). Choose suitable functional unit of the inventorying the CO2 emissions from the system (i.e., CO2 emission per functional unit). Fall 2015 Page 2

3. In the example of the question 2, the plywood box is manufactured from 12kg of plywood, 1.78kg of steel strips, and 0.22kg of steel nails. The functional unit in this example is one plywood box (since there is no comparison with other types of boxes). The steel producer provide both the strip manufacturer and nail manufacturer with steel. No recycle material is used. Transportation is excluded. The weight of the output (product) from each unit process is documented in the flow chart in question 2. CO2 emissions from each unit process is: Process CO2 emissions Unit Production Steel 1210 g/kg steel Hot rolling of steel strip

100 g/kg strip

Zinc coating of steel strip

15 g/kg coated strip

Production of nails 120 g/kg nails Production of plywood 128 g/kg plywood Production of plywood box

178 g/plywood box