Economical analysis of a new gas to ethylene technology

Ethylene is one of the most important petrochemical intermediates and feedstocks for many different products. The motivating force of this work is to compare a new process of ethylene production developed at Texas A&M University to the most common processes. Ethylene is produced commercially using a wide variety of feedstocks ranging from ethane to heavy fuel oils. Of them, the thermal cracking of ethane and propane using a fired tubular heater is the most common process in the United States. In Europe and Japan, where natural gas is not abundant, thermal cracking of naphtha using a fired heater is the most common process. In addition to these processes; ethylene could also be produced from crude oil by autothermic and fluidized bed techniques and from coal and heavy oils by synthesis from carbon monoxide and hydrogen. At Texas A&M University, a group of researchers developed a new process that can convert natural gas into liquids (GTL) or to ethylene (GTE). This technology is a direct conversion method that does not require producing syngas. When selecting a process for ethylene production, the dominant factor is the selection of hydrocarbon feedstocks. Based upon plant capacity of 321 million pounds of ethylene per year, this study has shown that using natural gas, as a feedstock, is more economical than using ethane, propane, naphtha, and other feedstocks. Therefore, it is more economical to convert natural gas directly to ethylene than separating ethane or propane from natural gas and then converting it to ethylene. A process simulation package ProMax is used to run the GTE process; and a software program, Capcost, is used to evaluate fixed capital costs of the GTE process. Finally, the cost index is used to update the cost of the other processes of ethylene production today.