Sustainability Assessment of Chemical Processes: Evaluation of Three Synthesis Routes of DMC

Table 7

Simulation results and cost calculations of reaction routes.

	Route A	Route B	Route C
Conversion of MeOH [%]	9.16	(1) Step:  100; (2) Step:  10.5	17
Selectivity to DMC [%]	90.56	(1) Step  100; (2) Step  50	97
Yield [%]	5.99	5.15	12.64
Atom economy [%] (Real)	7.19	8.47	15.17
Amount of DMC (kmol)	0.06	0.051	0.126
Concentration of DMC (vol-%)	85.6	85.9	85.4
CO2 emissions [kmol]	0.92	0	—
CO2 consumption [kmol]	0.08	1.00	—
CO2 balance	0.84	1	0
Energy consumption (specific) [MJ/DMC produced]	1152.8	−746.3	131.5
Energy consumption (Aspen) [MJ]	69.17	−38.06	16.57
Costs of feedstock (€/kmol)	CO2: 24.8	CH3OH: 28.9	CH3OH: 28.9
	CH3OH: 28.9	CO2: 24.8	O2: 13.4
		C3H6O: 72.6	CO: 199
	tot. 53.7	tot. 126.3	tot. 241.3
Operational costs (feedstock + process) [€]	53.7 + 18.7 = 72.4	126.3 − 10.3 = 116	241.3 + 4.5 = 245.8
Operational costs (feedstock + process)/DMC produced €/kmol	1206.7	2274.5	1950.8
Treatment cost/waste disposal cost	High disposal cost of methylformate; Water can be discharged to drain	By-product can be sold	Water can be discharged to drain