Question

Environmental engineering

2. A lifecycle assessment (LCA) was conducted to compare 31-gallon steel and plastic (HDPE) fuel tanks for cars. This question is about only the energy component of the LCA. There are three stages where energy is consumed: extraction of materials, tank manufacture, and use. A. Using the data in Table 2, calculate the energy for the steel tank and HDPE tank. In this part of the problem, consider only energy for materials and manufacturing. Which tank type requires the least energy for materials and tankmanufacturing? Be sure to include the scrap rate in your calculations. A scrap rate of 10% means that it takes 110 10-11 1 kg of material to produce one l 00 kg unit (10% of 111 kg is i i kg, leaving 1 1 1-11-100 kg for the product). Table 2: Energy for Materials and Manufacturing Tank mass (kg) Primary energy, materials (MJkg) Primary energy, manufacturing (MJkg) Scrap rate Steel 21.92 33.5 2.7 18.9% HDPE 14.07 80.98 14.0 1.7% B. In the LCA, we also must include the energy for the use of the tank. The steel and HDPE tanks have different masses and therefore affect the gas mileage of the vehicle differently. Over the lifetime of the vehicle (here,

Answer 1