Operation cost, utility, equation

The variable operating costs are given by raw materials consumed costs incurred for the operation of production lines such as utilities, operating supplies, and spare parts and some expenses at the distribution centers, such wrapping materials and nomeusable pallets. At a particular production facility h or i, the total raw material costs are determined by the total units produced of each product p and their corresponding unit of raw material costs MRC, and CRC. Then the network total raw material costs are given by Equations 3.4 and 3.5. 

Methanol synthesis plants utilizing the low-pressure process currently operate at capacities of 2 x 105 to 2 x 106 metric tons per year [15]. Such installations are composed of a synthesis gas production unit, the actual methanol synthesis reactor, and a separation and purification section. The production and purification of synthesis gas accounts for 50%-80% of the total cost of methanol production, with the remaining cost associated with the actual synthesis and purification of methanol [2, 8], Although a variety of carbonaceous feedstocks can be transformed into synthesis gas, the steam reforming of natural gas (Equation [4]) is by far the most common option, especially for large plants [2, 15-16] ... 

The relatively low partial pressure of carbon monoxide in the flash-tank has implications for catalyst stability. Since the rhodium catalyst exists principally as iodocarbonyl complexes (e.g., [Rh(CO)2l2] and [RtKCO LJ-), loss of CO ligands and precipitation of insoluble species (e.g., Rhl3) can be problematic. The conventional Monsanto process operates with a relatively high water concentration (10-15%, w/w) that helps to maintain catalyst stability and solubility (as discussed later). However, this operation results in a costly separation process to dry the product, typically requiring three distillation columns. The presence of water also results in the occurrence of the WGS reaction (Equation (2)), in competition with the desired carbonylation process, resulting in a lower utilization of CO. 

Table 8.2 gives data to estimate the individual cost items identified in Table 8.1 (both tables carry the same identification of individual cost terms). With the exception of the cost of raw materials, waste treatment, utilities, and operating labor (all parts of the direct manufacturing costs). Table 8.2 presents equations that can be used to estimate each individual item With each equation, a typical range for the constants (multiplication factors) to estimate an individual cost item is presented. If no other information is available, the midpoint value for each of these ranges is used to estimate the costs involved. It should be noted that the best information that is available should always be used to establish these constants. The method presented here should be used only when no other information on these costs is available. 

Determine the optimal recovery of IPA and acetone for this system using an objective function of the EAOC based on an 8000h operating year. Any simulations should be carried out using a suitable process simulator using the UNIFAC K-value option and the latent heat enthalpy option. The overall heat transfer coefficient for E-403 maybe taken as 200 W/m K. Utility costs should be obtained from Chapter 8, and the cost of E-403 is approximated by the following equation ... 

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