Operating margin,economic

Establishing mass balances after pyrolysis tests is also important for economic reasons. Economic figures are related directly with the operating margins, being the difference between the value of the products and the cost of raw materials. 

Often the coupling of the membrane unit with the bioreactor results in significant synergy as in the study of O Brien et al. [6.15] on the application of PVMBR to ethanol production, which we discussed in Chapter 3. The required bioreactor volume for the PVMBR system was smaller than that of the conventional system by a factor of 12. Nevertheless, it turns out that the PVMBR-based process is still 25 % more expensive than the classical batch fermentation process in terms of capital costs despite the substantial reduction in the required reactor volume. This cost differential is not only due to the membrane costs, which are, themselves, substantial, but also due to the cost of the additional hardware associated with membrane operation. The application of MBR for the ethanol production by fermentation faces marginal economics, since ethanol is a relatively cheap commodity chemical. 

With the much greater operating margins attainable under foreign economic conditions, the petrochemical refinery in its basic all-chemical configuration will inherently be much more desirable than in the United States. I expect to see the construction of a number of such units in various foreign countries. 

The objective function (economic value) representing the economic operating margin for the column is shown in Figure 14.2, which is defined as the difference between the value of products (top butane product and pentane bottom pentane product) and costs of feed and energy. The value function features two discontinuities. The first, which occurs when the composition of the bottom product is about 1 % butane, corresponds to a change in the top product from off-spec to on-spec. The second discontinuity occurs when the bottom product becomes off-spec at 5% butane. 

Although numerous cases have been documented where petroleum refineries have simultaneously reduced pollution outputs and operating costs through pollution prevention techniques, there are often barriers to their im-plementation. The primary barrier to most pollution prevention projects is cost. Many pollution prevention options simply do not pay for themselves, or the economics often appear marginal. Corporate investments typically must earn an adequate return on invested capital for the shareholders and some pollution prevention options at some facilities may not meet the requirements set by company policies. 

On the micro-economic level, simple company value chains consisting of buying products to optionally make other products out of it, to distribute and sell these products with a margin to customers become complex networks with globally spread out locations. Globally operating companies face the task to manage volumes and values in this network in a profitable way to ensure competitiveness and business sustainability. 

The evaluation of carriers and catalyst compositions showed that significantly higher SO2 oxidation activity could be achieved with Cs as a promoter under the operating conditions downstream the intermediate absorption tower as demonstrated by the results in Table 1, where the activity compared to the standard product is increased by more than a factor 2. This was clearly sufficient for the introduction of VK69 to the market as a new sulphuric acid catalyst. The activity results for different melt compositions were used to optimise the vanadium content and the molar ratios of K/V, Na/V. and Cs/V. However, the choice of Cs/V was not only a question of maximum activity, because of the significant influence of the Cs content on the raw material costs (the price of caesium is 50-100 times the price of potassium on a molar basis). Here, the economic benefits obtained by the sulphuric acid producer by the marginal activity improvement at high Cs content also had to be taken into account. 

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