Ethylene Prices Worldwide

About Ethylene. Ethylene (a.k.a. Ethene) is an unsaturated organic compound, the simplest member of the alkene class of hydrocarbons. Even though it has no direct use, being used almost exclusively as a building block, Ethylene is the largest-volume petrochemical produced worldwide. It has one double bond and, in room temperature, ethene is a sweet odor and taste gas, colorless and extremely flammable. It has been produced since the 1930s; however, its production grew rapidly in the middle of the twentieth century, when oil and chemical companies began separating it from refinery waste gas and producing it from natural gas and ethane (obtained from byproduct refinery streams). Ethylene may also be produced from renewable sources. In such cases, it may be referred to as Bio-Ethylene or Green Ethylene.

Most of Ethylene production is based on feedstocks derived from petroleum, being steam cracking – high temperature pyrolysis in the presence of steam – the main technology used. These feedtocks are grouped as gaseous (ethane, propane, n-butane, natural gas liquids and any mixture of them) and liquid (field condensates, natural gasoline, BTX raffinate, light naphtha, naphtha). Such different feedstocks generate slates of characteristic product yields with varying compositions. In general, gaseous feedstock have high yields of Ethylene with small amounts of by-products, while while liquid feedstocks have lower Ethylene yields with larger amounts of by-products.

Growing environmental concerns have increased interest over alternative routes to petroleum-based ethylene production, specially the dehydration of bio-ethanol. With such a diverse range of derivative products, Ethylene demand is very sensitive to economic cycles, being often used as a reference in the performance evaluation of the petrochemical industry. The economics of Ethylene production is largely dependent on the prices for feedstocks and co-products, mainly propylene. It is worth noting that, in general, heavier feeds leads to higher costs of production and capital investment required.

Ethylene Handling. It is stored as liquid under high pressure or at low temperatures. However, most of the times, Ethylene is directly supplied to consumers, via pipeline grids, usually under a pressure of 4–100 MPa. The upper end of the pressure range is significantly above the critical pressure. Below critical conditions, the temperature must be grater than 4 °C to prevent liquefaction. Ethylene is also transported by ship, barge, railcar, and tank truck. Ships can transport between 2,000 and 6,500 t. These vessels are of the semi-refrigerated type, and transport liquid ethylene at atmospheric pressure and -104 °C. The tankers include reliquefaction plants on board since it is too expensive to vent Ethylene.

Ethylene Production. Ethylene is primarily produced by the pyrolysis of hydrocarbons and by recovery from some refinery products. It can also be produced from other pathways, such as ethanol dehydration or methanol-to-olefins plants. Raw materials and the respective production processes employed in the manufacturing of Ethylene are listed below.

Ethylene Uses. The uses and applications of Ethylene may vary according to its specification. The main forms of Ethylene are technical grade (95% min purity) and polymer grade (PG, 99.9% min purity).