COMPARATIVE-ASSESSMENT OF THERMODYNAMIC EFFICIENCIES AND LOSSES FOR NATURAL GAS-BASED PRODUCTION PROCESSES FOR HYDROGEN, AMMONIA AND METHANOL

Results are reported of comparisons based on energy and exergy analyse s of production processes for hydrogen, ammonia and methanol from natu ral gas. A version of the Aspen Plus process-simulation computer code, previously enhanced by the author for exergy analysis, is used in the analyses. Overall efficiencies are determined to range widely, from 4 0 to 86% for energy efficiencies, and from 41 to 78% for exergy effici encies. The losses in all processes are found to exhibit many common f actors. Energy losses associated with emissions account for 100% of th e total energy losses, while exergy losses associated with emissions a ccount for less than 10% of the total exergy losses. The remaining exe rgy losses are associated with internal consumptions. It is anticipate d that the results will prove useful to those involved in decision-mak ing regarding alternative uses for natural gas.