After conducting heat integration in the simulation, an
economic analysis was carried out to analyze the potential
profits of the proposed process in comparison to the original
one before heat integration. Four basic assumptions were
made in the economic evaluation. (1) The overall throughput
of the process was 1000 kmol/h flue gases with a typical
composition found in a power plant. (2) Operating hours were
based on 8000 h/year. (3) Catalysts used in reactions were not
considered. (4) Feed gases including flue gas and methane
were free of solid impurities. Flue gas was not considered into
the overall costs calculation, as it is a waste stream. In addition,
all costs shown are in U.S.$. The costs of chemicals used
in this study are given in Table 1. In this work, due to the lack
of data for fixed capital cost, depreciation, taxes and so on, the
economic analysis only accounts for money received by
selling the products (INCOME), feed cost (FCOST), and utility
cost (UCOST). The operating profit was defined as follows: