Ethane production cost

Over all of the products, the production cost is 7.19/GJ. This produces ethane at 373/t. However, if the natural gasoline is sold according to the prevailing crude oil price (assumed to be 70/bbl) then this will generate by-product credit of 556 million this is based on valuing the gasoline as naphtha with oil at 70/barrel. The basis of this oil price as a reference (index) price is discussed in the Appendix. This approach reduces the production costs and hence the unit ethane and LPG costs. The ethane production cost is 341/t. 

The process achieves about 90% conversion of ethane to VC. With the elimination of so many intermediate steps compared to the traditional EDC route, this process could achieve VC production cost savings of up to 35% anywhere an adequate supply of ethane can be found. That could even include the recycle stream from a heavy liquids olefins plant. If these killer economics persevere, this technology could grab all the growth in VC capacity and even replace most of the conventional VC capacity in a couple of decades. That s what happened to the acetylene-based route to VC when the ethylene-based route came on stream in the mid-20th century. 

Figure 6 indicates the ethylene production costs from various feedstocks in a U.S. billion lbs/yr ethylene plant based on premium valued by-products. If the predicted ethane and propane increases did in fact... 

With imported naphtha at, say 1.1 /lb and aromatics at current values, ethylene cost is 1.94 /lb. However, with finished aromatics valued at 5 /gal over the current base values, production cost drops to 1.59 /lb. The breakeven curves for naphtha vs. ethane, propane, and n-butane are given in Figures 8, 9, and 10. These assume premium byproducts, with aromatics valued above current levels, but do not include the effect of increased propylene and butylene valuations that would further accentuate the picture. With 1.1 /lb naphtha and aromatics at 5 /gal above current prices, the breakeven prices for ethane, propane, and n-butane are 0.33, 0.7, and 0.83 /lb, respectively. Such prices are... 

Consumers can also negotiate with feedstock suppliers on upfront payments or payment terms under which they pay a higher price than the lowest market price at the trough, but pay lower prices when product prices spike. An interesting application of this is the potential for an ethane cracker operator to convert the economics of its cracker to those of a virtual naphtha cracker, by paying an integrated gas producer-processor a price for ethane indexed to naphtha-based ethylene production costs. 

There is often no single feedstock choice, since feedstock costs frequently vary erratically over a period of several years. A general guide to the influence of feedstock on capital investment of the entire pyrolysis for ethylene production is shown in Fig. 7. Net raw material costs for an ethylene plant often account for about 50-60% of the production costs, depending on whether the feedstock is a light material such as ethane or a heavier material such as naphtha. 

The economics of large gas plants (>1000 MMscfd gas) is of importance in understanding the production cost of ethane and LPG for petrochemical feed and to shed light on the economic drivers in refinery and petrochemicals operations. Because of the large flow of gas, these plants produce large volumes of natural gas liquids . 

Figures 3.5 and 3.6 give the sensitivity of the liquids production cost to input gas price and oil price, with gasoline sold prior to the distribution of the costs. The basis of the costs is in energy terms ( /GJ). This makes the product cost for ethane, propane and butane very similar and ethane is chosen as the example.

Setting the ethane price to 7.19/GJ (which corresponds to a gas plant price with gas available at 6.37/GJ) gives the ethylene production cost of 726/tonne for the OPEN system and 869/toime for the CLOSED system. The cash flows are detailed in Table 7.3. 

Figure 7.3 Breakdown of ethylene production costs -ethane feed - OPEN system...

For ethane feedstock, of most interest is the sensitivity of the production cost to the price of ethane. In many jurisdictions, the ethane price is related to the price of gas. In turn this is related in many parts of... 

Small scale operations are widely used to produce small amounts of ethylene for a specific purpose (e.g. styrene). This graph illustrates that high ethane prices are a significant threat to these operations because the cost of ethylene transport from a larger operation (typically 100/t for ship based transport) is lower than the rise in production cost due to the loss of economy of scale. 

After allowance is made for ethane flaring and the carbon dioxide emissions, the CLOSED system produces approximately 0.6 tonne of carbon dioxide per tonne of olefin. Using the same cost of carbon dioxide the result is that production cost is lifted from 869 to 890/tonne. 

Following the same methodology for the cracking of ethane, the production cost of ethylene by propane cracking in an OPEN system is shown in Table 8.2. In this scenario, all of the products are on-sold to downstream operations or valued at an opportunity cost. 

DDT l,l,l-Trichloro-2,2-bis -chlorophenyl) ethane. DDT is probably the best known of the organic insecticides that have been developed in the last twenty years. The greater part of the United States output is produced in plants with very large annual capacities, thus having very low production costs. 

A report by John Richardson in 2010 titled Saudi Feedstock Problems Worsen, [ 1 ] discussed the complex issues that have at the very least led to a shortage of ethane availability in Saudi Arabia. This ethane shortage was due to several factors such as (a) lower crude oil production, (b) lower levels of ethane (dry crude) in the crude oil produced, and (c) the relatively high cost of replacing the ethane-based crude oil with ethane-based natural gas production. In addition, as Richardson noted, these ethane production problems in Saudi Arabia also coincide with the shale gas revolution in North America. This ethane shortage in Saudi Arabia has led to an ethylene cost of 150/ton and could rise to 300-350/ton on limited supply of ethane. On the other hand, due to the increase in ethane availability in North America, ethylene costs have been reduced from 700/ton in about 2008 to 400-450/ton in 2012, which eliminates most of the feedstock... 

It is possible to point out a number of conclusions from this figure. Firsf of all if is understandable why much of the investment within the petrochemical industry is directed to the Middle East. The feedstock, ethane from flare gas, is cheap and a dedicafed efhane cracker requires a relatively low investineni. If is also seen that the coming investments in bioethylene in Brazil, with a production cost of approximately 800/tonne, are very competitive with the fossil-based US alternatives, having a production cost of roughly 1050/tonne. The variable cost is relatively low but compared to the Middle East ethane alternative the investment is higher due to the fermentation plant. Furthermore, it is important to point out that the investment for the ethanol-to-ethylene plant is very low as seen for ethanol-purchased alternatives. For these cases it is important to stress that these are valid for the conditions in the USA, i.e. the price level of ethanol in the USA. In Europe it is possible to get exemption from the import duty on ethanol imported from Brazil. This would lead to a variable cost of approximately 700/tonne and thus a production cost of approximately 900/tonne. 

Port Arthur Steam Cracker, Texas (USA) 2013 The Port Arthur steam cracker is one of the biggest in the world, with a capacity of 1 Mtpa of ethylene. The project was commissioned in 2001 to process naphtha distiled from petroleum. In response to petroleum product price hike and the emergence of abimdant gas resources, they adapted the steam cracker to give it flexibility and maintain its competitiveness. It can now use as a feedstock ethane, which costs around 30 per barrel of oil equivalent (boe) versus around 100/boe for naphtha and liquefied petroleum gases such as butane and propane, which are also cheaper. 

The ethylene feedstock used in most plants is of high purity and contains 200—2000 ppm of ethane as the only significant impurity. Ethane is inert in the reactor and is rejected from the plant in the vent gas for use as fuel. Dilute gas streams, such as treated fluid-catalytic cracking (FCC) off-gas from refineries with ethylene concentrations as low as 10%, have also been used as the ethylene feedstock. The refinery FCC off-gas, which is otherwise used as fuel, can be an attractive source of ethylene even with the added costs of the treatments needed to remove undesirable impurities such as acetylene and higher olefins. Its use for ethylbenzene production, however, is limited by the quantity available. Only large refineries are capable of deUvering sufficient FCC off-gas to support an ethylbenzene—styrene plant of an economical scale. 

If the production of vinyl chloride could be reduced to a single step, such as dkect chlorine substitution for hydrogen in ethylene or oxychlorination/cracking of ethylene to vinyl chloride, a major improvement over the traditional balanced process would be realized. The Hterature is filled with a variety of catalysts and processes for single-step manufacture of vinyl chloride (136—138). None has been commercialized because of the high temperatures, corrosive environments, and insufficient reaction selectivities so far encountered. Substitution of lower cost ethane or methane for ethylene in the manufacture of vinyl chloride has also been investigated. The Lummus-Transcat process (139), for instance, proposes a molten oxychlorination catalyst at 450—500°C to react ethane with chlorine to make vinyl chloride dkecfly. However, ethane conversion and selectivity to vinyl chloride are too low (30% and less than 40%, respectively) to make this process competitive. Numerous other catalysts and processes have been patented as weU, but none has been commercialized owing to problems with temperature, corrosion, and/or product selectivity (140—144). Because of the potential payback, however, this is a very active area of research. 

Three industrial processes have been used for the production of ethyl chloride hydrochlorination of ethylene, reaction of hydrochloric acid with ethanol, and chlorination of ethane. Hydrochlorination of ethylene is used to manufacture most of the ethyl chloride produced in the United States. Because of its prohibitive cost, the ethanol route to ethyl chloride has not been used commercially in the United States since about 1972. Thermal chlorination of ethane has the disadvantage of producing undesired by-products, and has not been used commercially since about 1975. 

Ethane feed gives the lowest cost of production and the lowest capital investment. As the feeds become successively heavier, cost of production increases as well as the capital investment required. Depending on the cost of feedstock and the value of the co-products, processing heavier feedstocks can lead to lower returns on investment. Table 13 shows the effect on capital investment for various feedstocks as well as for a range of capacities. 

Methanol dehydrogenation to ethylene and propylene. In some remote ioca-tions, transportation costs become very important. Moving ethane is almost out of the question. Hauling propane for feed or ethylene itself in pressurized or supercooled vessels is expensive. Moving naphtha or gas oil as feed requires that an expensive olefins plant with unwanted by-products be built. So what s a company to do if they need an olefins-based industry at a remote site One solution that has been commercialized is the dehydrogenation of methanol to ethylene and propylene. While it may seem like paddling upstream, the transportation costs to get the feeds to the remote sites plus the capital costs of the plant make the economics of ethylene and its derivatives okay. 

Steam crackers provide the traditional cost-effective approach for olefins production from lighter feed stocks such ethane, propane, naphtha, and AGO. However, these options typically provide higher E/P ratio. To meet the increasing demands of ethylene and particularly propylene, refiners and petrochemical producers are planning integrated facilities. The objectives are ... 

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