Ethane feedstock

ElexibiHty allows the operator to pick and choose the most attractive feedstock available at a given point in time. The steam-cracking process produces not only ethylene, but other products as weU, such as propylene, butadiene, butylenes (a mixture of monounsaturated C-4 hydrocarbons), aromatics, etc. With ethane feedstock, only minimal quantities of other products ate produced. As the feedstocks become heavier (ie, as measured by higher molecular weights and boiling points), increasing quantities of other products are produced. The values of these other coproduced products affect the economic attractiveness and hence the choice of feedstock. 

Ethane feed, 10 625 Ethane feedstock, 18 558, 559 Ethane-heptene mixtures... 

Increasing ethane feedstock, hence less steam cracking propylene production... 

The appeal of an acetic acid process, based on ethane oxidation, lies mostly in the absence of the need for the energy demanding step for syngas production. On the other hand, it has to compete not only with the well established methanol carbonylation (Section 4.2), but also with the current utilization of ethane in steam crackers for ethylene manufacture. In fact, ethane feedstock becomes attractive for acetic acid production if it is locally abundant and can be supplied at minimal cost, e.g., in a petrochemical complex close to a large gas field. The construction of a semi-commercial plant of 30 kt/a in the Persian Gulf region has been announced. 

In practice, run length is as long as 90 days on an ethane feedstock. 65 with naphtha, and 40 with gas oil. 

Mexico has a nameplate ethylene capacity of 1.384 million tonnes. This is produced by three operation owned by Petroeleos Mexicanos. All operations use ethane feedstock. 

The ethane market price is set by demand, which is influenced by the relative ratio of oil to gas. In large markets with flexible fuel cracking operations (US, EU), if oil price is high, ethylene producers switch to ethane feedstock. If oil price is low, ethylene producers switch... 

Table 7.4 Margin Calculations using Ethane Feedstock...

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... 

Economics Once-through pyrolysis yields range from 57 wt% (ethane, high conversion) to 28 wt% (heavy hydrogenated gasoils) ethylene. Ultimate yields for ethylene of 85% from ethane feedstock and 32% from liquid feedstock are achieved. The ethylene plants with USC furnaces and an ARS/HRS recovery section are known for high reliability, low energy consumption, short startup time and environmental compliance. 

Utilization of these vast new natural gas reserves by utility companies to generate electricity, liquefied natural gas (ENG) exporters, natural gas-to-liquids plants (i.e., gas-to-diesel plants), and in applications such as in transportation using compressed natural gas could significantly increase the ethane supply in North America (United States and Canada) bringing down ethane feedstock costs for the manufacture of ethane-based ethylene. 

In the second half of 2011, the United States ethane demand grew to about 933,000 barrels per day from 812,000 BPD in 2009 [14]. However, distribution bottlenecks have increased the ethane feedstock cost to 95 cents a gallon in late 2011, from 60 cents a gallon in early 2011. 

Dow will add about 5 billion poxmds of ethylene capacity in the United States [16,18] through 2017, primarily on the Gulf Coast, with Range Resources supplying Dow s Louisiana operations the shale-gas-based ethane feedstock from the Marcellus region in Southwest Pennsylvania. The cost of ethylene produced from ethane is approximately 600 a ton as compared to 1,200 a ton for ethylene produced from crude-oil-based naphtha [17]. 

One major problem with the availability of polychloroprene in the recent past has been the availability of butadiene monomer. Because of the gradual switchover from naphtha feedstocks from petroleum to ethane feedstocks from natural gas in the production of ethylene for the plastics industry, there are fewer C4 streams available for butadiene production. Ethylene plants are gaining significant economic savings by making this feedstock conversion from naphtha to ethane. This has resulted in significant shortages of butadiene to the rubber industry. However, there is optimism now that butadiene will be more available than before because... 

Propylene is one of the most important feedstocks for the petrochemical industry and can be used in the production of a wide variety of products such as polypropylene, acrylonitrile, cumene, oxo-alcohols, propylene oxide, acrylic acid, isopropyl alcohol, etc. (Weissermel and Arpe, 2007). Nowadays, the propylene demand is increasing faster than the ethylene demand. The expected growth of propylene with respect to ethylene exceeds the ratio obtained from steam crackers because a portion of steam crackers is now using inexpensive ethane feedstock (Bricker, 2012 Sanfilippo and Miracca, 2006). The dehydrogenation of propane (DHP) offers an option to capture the marginal, additional capacity needed to compensate for the imbalance (Buyanov and Pakhomov, 2001). A number of technologies are commercially available for the DHP to propylene for example, Oleflex, Catofin, Star, PDH, and FBD (Abdullah, 2007 Eisele and KiUpack, 2000). From 2011, several DHP plants have been planned to be built in China with the total capacity exceeding 6 miUion tons per year (Zhu, 2012). 

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