In comparison with the traditional route using phosgenation of methanol to produce (DMC) Dimethyl Carbonate (CH3)2CO, the three safer routes for its production are: Route A: direct synthesis from carbon dioxide and methanol Route B: trans-esterification of methanol and propylene carbonate using ionic liquid as catalyst Route C: oxidative carbonylation of methanol Some calculated values of sustainability indicators of the three reaction routes A,B,C are given in Table 5.1, based on the multi-criteria approach of attributing the value 1 for the most preferred performance, 0 for the least preferred and where applicable a normalized value for performance in-between. Appendices 2, 3 and 4 provide respectively, Process Description, Facts and Assumptions and Simulation Results/Cost Calculations as the basis for assigning/calculating the sustainability indicator values in Table 5.1. b) What are the values of sustainability of Routes A, B and C, for those indicators that have been left blank (-) in Table 5.1, i.e. Energy intensity, Wastes, Yield, Feedstock price, Chemicals safety? Indicate your basis for arriving at the value. (15 marks) c) Based on the total sustainability indicator value for each route, what is your recommendation of choice for the route to produce DMC and why? (5 marks) Table 5.1: Sustainability Indicator Values In comparison with the traditional route using phosgenation of methanol to produce (DMC) Dimethyl Carbonate (CH3)2CO, the three safer routes for its production are: Route A: direct synthesis from carbon dioxide and methanol Route B: trans-esterification of methanol and propylene carbonate using ionic liquid as catalyst Route C: oxidative carbonylation of methanol Some calculated values of sustainability indicators of the three reaction routes A,B,C are given in Table 5.1, based on the multi-criteria approach of attributing the value 1 for the most preferred performance, 0 for the least preferred and where applicable a normalized value for performance in-between. Appendices 2, 3 and 4 provide respectively, Process Description, Facts and Assumptions and Simulation Results/Cost Calculations as the basis for assigning/calculating the sustainability indicator values in Table 5.1. b) What are the values of sustainability of Routes A, B and C, for those indicators that have been left blank (-) in Table 5.1, i.e. Energy intensity, Wastes, Yield, Feedstock price, Chemicals safety? Indicate your basis for arriving at the value. (15 marks) c) Based on the total sustainability indicator value for each route, what is your recommendation of choice for the route to produce DMC and why? (5 marks) Table 5.1: Sustainability Indicator Values