Polypropylene (PP) is a hydrocarbon polymer produced from the reaction of chemicals obtained from crude oil. PP is used in many applications including the manufacture of food containers such as yoghurt pots. Like plastic bags (covered in section 16.2.1 in Part 4 'Materials and resources'), PP containers present challenges to the engineering community when they reach the end of their lives. PP containers can be re-used, and some manufacturers encourage this. However, large quantities are discarded as waste each year. Two possible disposal options are: PP can be recycled into new containers or other products. PP releases a lot of energy when burned, so it is a useful potential fuel for waste fired power stations (see Activity 8.1a) along with other components of the waste stream. (Apart from the greenhouse gas CO2, PP does not release harmful chemicals into the atmosphere when burned). a. In Chapter 14, Activity 14.15, you were asked to list the activities involved in producing a can of baked beans and getting it to market. For this question, make a similar list to cover each process in the chain of activities needed to produce a PP container filled with plain yoghurt, from the raw materials to the point of purchase by the customer. The first three stages of production have been provided below for you. You are not expected to include details of the manufacturing method. Continue the list of bullet-points with another 8 suggestions to cover the entire range of activities to the point of sale to the customer. Each stage should be one or two sentences long. Extraction of crude oil from the ground. Refining of the crude oil and production of chemicals needed to produce PP. Production of PP and processing into pellets.