Optimal Design of a Shale Gas‐Based Ethylene Plant

PEDROZO, HÉCTOR ALEJANDRO; RODRIGUEZ REARTES, SABRINA BELÉN; CHEN, Q; GROSSMANN, I.E. ; DIAZ, MARÍA SOLEDAD

Villa Carlos Paz, Córdoba, Argentina

Congreso; IV Reunión Interdisciplinaria de Tecnología y Procesos Químicos (RITeQ, 2018); 2018

IPQA-CONICET-FCEFyN- UNC

The exploitation of unconventional gas is increasing worldwide, associated with the development of hydraulic fracturing horizontal drilling technology, which has made profitable the recovery of shale gas. The US Energy Information Administration forecasts that world natural gas production will increase, driven by shale gas exploitation developed mainly in six countries: USA, China, Argentina, Canada, Mexico and Algeria (EIA, 2016).From shale gas exploitation, natural gas liquids (NGLs) are available at low prices (Amghizar et al., 2017). The abundance of low-cost ethane encourages ethylene production, since the synthesis of this olefin from ethane is more profitable than from naphtha feedstocks.Ethylene is a fundamental building block for the synthesis of bulk chemicals and intermediates. The conventional process to produce ethylene is via thermal cracking of hydrocarbons with steam, which is called steam cracking (SC). This is a mature technology with more than 50 years of application and development, and in many cases it has the best economics.However, SC is an energy intensive process and produces significant CO2 and NOx emissions due to the high temperature required within the cracking furnaces. For this reason, there is increasing interest in the development of alternative processes to improve energy efficiency and environmental performance.In this work, ethane-based ethylene production by conventional steam cracking and alternative technologies are studied by means of a superstructure optimization approach. The optimal solution includes the design of reactor units, the separation train, and utility system, which comprise the key components of the plant. Equipment sizing is performed and capital cost is estimated using conventional equipment cost correlations (Ulrich and Vasudevan, 2004; Towler and Sinnott, 2012). Net present value (NPV) is considered as the objective function