European ethylene production costs

Figure 2. Effect of severity on European ethylene production costs (1000 MM Ibs/yr ethylene production from naphtha feed)...

Table X shows the effect of capacity on ethylene production costs for a European naphtha plant. Note that investment-based items such as return on investment and depreciation and others included in operating cost decrease, per unit of ethylene produced, as plant size gets larger.

The ethylene production cost for a 1000 MM lb/yr plant is 2.5 /lb (this figure also appears in the European naphtha column of Table VIII). For a 20% increase in capacity to 1200 MM lb/yr, the ethylene production cost drops to about 2.4 /lb. For a decrease in capacity of 60% from 1000 to 400 MM lb/yr, the production cost increases by almost 30% to 3.2 /lb. Table X shows that the advantages of scale diminish drastically as capacity is increased. By way of example, the decrease in production cost going from 400 to 700 MM lb/yr is about 0.5 /lb C2 the next 300 MM lb/yr increment (to a 1000 MM lb/yr) brings only a 0.2 /lb. reduction in production costs. 

Production Costs. The effect of varying severity on ethylene production costs is given in Figure 2. Both premium and fuel by-product situations are covered. The curves apply to a billion lb/yr European naphtha pyrolysis plant. 

Figure 3 presents the effect of feed price on ethylene production costs in a billion lb/yr European plant for naphtha, light gas oil, and heavy gas oil feedstocks based on premium by-product valuations. 

The synthesis of acetaldehyde by oxidation of ethylene, generally known as the Wacker process, was a major landmark in the application of homogeneous catalysis to industrial organic chemistry. It was also a major step in the displacement of acetylene (made from calcium carbide) as the feedstock for the manufacture of organic chemicals. Acetylene-based acetaldehyde was a major intermediate for production of acetic acid and butyraldehyde. However the cost was high because a large energy input is required to produce acetylene. The acetylene process still survives in a few East European countries and in Switzerland, where low cost acetylene is available. 

With a total consumption of —90 kt in 2005, tetraacetyl ethylene diamine (TAED) [14] (Figure 16.5) is the most widely used bleach activator. The product fulfills the basic principles of green chemistry [15], as it has maximum atom efficiency both starting materials (ethylene diamine and acetic acid anhydride) are fully incorporated in the molecule. Its low toxicity profile and ready biodegradability reinforce the sustainability claim. The activator is weight-efQcient, as one molecule generates two molecules of peracetic acid. Under European washing conditions at SO-bO C, it has an excellent cost-performance ratio. The kinetic stability of peracetic acid at lower tanperatures, however, limits its use to warm wash applications. 

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