Petrochemical plant naphtha cracking

All of the cracking operations use naphtha as feedstock. The future developments of Taiwan s petrochemicals business are linked to developments in the refinery sector which provide the feedstock. Until recently, the supply of petroleum products was in the hands of the government owned Chinese Petroleum Corporation (another CPC ) which operated three refineries and a condensate splitter. These operations supplied the downstream petrochemical plants with naphtha. However, the advent of Taiwan s entry into the WTO has broken this monopoly and FPC has established itself as Taiwan s first private refiner. The FPC refinery was built with the intention of facilitation feed supply to its new crackers. This opening of the petroleum market is allowing the entry of other players and some of the world oil majors have begun to enter the market. 

Finally, Britto et al. used a Cu/resin catalyst (which was then carbonized) for phenol abatement in industrial wastewater from a naphtha cracking unit of a petrochemical plant. The wastewater contains about 60 mg phenol, was oil and grease free, and various contaminants were present phosphate, sulfate, sulfide, NH3, and traces of BTX. A nearly total phenol conversion at around 40°C (pH close to neutral) was observed, while the COD abatement was 35%, although the contact time and which part of phenol was adsorbed was not indicated. Copper leaching (10 mg L ) was also present. 

About 80% of petrochemicals are produced with the olefins and aromatics from steam crackers. A typical 500,000 tes/year ethylene plant would crack up to 1.6 million tes/yearof naphtha, giving the fractions shown. Uses of individual products are listed. 

Cracked Gas Drying. Ethylene and propylene are two of the most important petrochemical raw materials today. They are manufactured by a thermal cracking of ethane, propane, or naphtha. One of the important separation-purification steps in the production of ethylene and propylene is removal of water before low temperature separation. Although alumina has been the most commonly used desiccant in drying cracked gas in the past, 3A molecular sieve adsorbents have an overall economic advantage 32), and many cracked gas plants are using the 3A molecular sieves today. 

This process flourished, particularly in the United States, where an abundant supply of low cost ethylene from ethane and liquified petroleum gas (LPG) rapidly developed throughout the 1960s and 1970s. Today more than 96 0 of vinyl chloride in the United States is based on the balanced process. In Europe, ethylene based on cracking more expensive naphtha and gas oil favored the acetylene technology for vinyl chloride for a time, but, today, most European plants are also based on the balanced process. Of course, today, acetylene is almost nonexistent as a petrochemical feedstock and vinyl chloride plants worldwide are the balanced ethylene-based process. 

Most olefins of petrochemical interest are produced by thermal cracking of naphtha feed stock, yielding about 12-14 million metric tons/year ethylene[l]. A Hungarian olefin plant, completed in 1975, is also operated on a naphtha feedstock. Yields and relative amounts of the main products greatly depend on the qualities of the naphtha feedstock pyrolyzed and the parameters of the cracking operation[2,3]. A detailed study of the pyrolysis is, therefore, of great industrial significance. 

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