(521f) Achieving Product Specifications for Ethane through to Pentane Plus from NGL Fractionation Plants

This paper examines the techniques that may be applied in evaluating processing options in the production of ethane, propane, butane and pentane plus products from NGL liquids.

The paper reviews the processing routes in the fractionation of NGL liquids in order to produce high quality products including consideration of mercaptans and H₂S in the upstream gas plants.

The paper makes reference to a recent GASCO project to upgrade their fractionation plant at Ruwais in Abu Dhabi. The design of this plant had to consider processing difficulties associated with NGL liquid feeds from sour upstream fields, where the processing route applied to achieve one specification may be detrimental to achieving another. These specifications include sulphur levels, paraffin content and RVP requirements.

In addition, value-engineering techniques were applied in parallel to the conceptual design and FEED to produce resulting Capex and Opex reduction and improved overall operability.

Increasingly, Energy Companies are looking to optimise their developments and this paper highlights some of the key issues that should be considered in the design of NGL fractionation trains and the production of high quality products.