NGL Fractionation Train

Client: ONEOK
Completion Date: 2013
Location: Mont Belvieu, Texas


ONEOK increased its presence in the Mont Belvieu natural gas liquids (NGL) fractionation market with the installation of a grassroots 75,000 barrels per day (BPD) fractionation unit, designed and constructed by Burns & McDonnell. Design began in the conceptual phase (FEP-2) and progressed through detailed scope (FEP-3) to produce a definitive cost estimate (±10%). We also executed detailed design, procurement and construction for the project.

The new plant processes 75,000 BPD of raw Y-Grade feed, required new facilities and equipment for raw feed handling, fractionation, product pump out, and auxiliary treating and utility systems to separate the raw feed into recoverable products. The plant is designed to recover ethane, propane, isobutane, normal butane, and natural gasoline. The recovered products from the NGL fractionation units are pumped from independent surge drums, using a series of booster and pipeline pumps through a metering skid for custody transfer. The final products are delivered to storage or directly to pipeline.

The scope of the project was broken into three areas. Those areas included the ISBL (Inside Battery Limits), OSBL (Outside Battery Limits), and off-sites. The ISBL consists of raw feed handling, feed dryer system, fractionation, sulfur removal and treating, intermediate product storage, and required utility systems such as propane refrigeration compression, hot oil heaters and circulation system, amine regeneration, and ammonia storage. The OSBL consisted of the cooling tower, water treatment plant, instrument air compressors, flare gas recovery, and flare system. The off-sites consisted of the raw water canal lift station, substation, utilities, and control room adjacent to an Admin Building provided by ONEOK.

Engineers involved in the design were an integral part to driving mechanical completion and turnover from construction to ONEOK, providing knowledge of design intent as needed. Following mechanical completion, we aided ONEOK in all pre-commissioning, commissioning and startup activities, including operator training.


  • Front end planning
  • Definitive estimate
  • Detailed design
  • Procurement
  • Construction
  • Startup and commissioning


  • Grassroots site
  • 75,000 BPD fractionation unit
  • Modular piperacks 
  • Shop fabricated piping
  • All required utilities infrastructure