Page 243 - Analysis, Synthesis and Design of Chemical Processes, Third Edition

Estimate the utility cost of a heat-transfer medium heated in a fired heater using natural gas as the fuel.

Assuming that the heat-transfer medium is heated in a process heater that is 80% efficient and uses natural
gas at $11.10/GJ as the fuel source, we get

Cost of 1 GJ of energy = (1)(11.10)/(0.80) = $ 13.88/GJ

Assuming a 90% efficient heater, we get

Cost of 1 GJ of energy = (1)(11.10)/(0.9) = $ 12.33/GJ

8.4 Raw Material Costs

The cost of raw materials can be estimated by using the current price listed in such publications as the
Chemical Market Reporter (CMR) [14]. A list of common chemicals and their selling price, as of August
2006, are given in Table 8.4. Current raw material and product chemical prices may be obtained from the
current issue of the CMR [14]. To locate costs for individual items, it is not sufficient to look solely at the
current issue, because not all chemicals are listed in each issue. It is necessary to explore several of the
most recent issues. In addition, for certain chemicals large seasonal price fluctuations may exist, and it
may be advisable to look at the average price over a period of several months.

Table 8.4: Costs of Some Common Chemicals*