Performance investigation of a power, heating and seawater desalination poly-generation scheme in an off-shore oil field

Performance investigation of a power, heating and seawater desalination poly-generation scheme in an off-shore oil field

Type	Journal Article
Author	Valérie Eveloy
Author	Peter Rodgers
Author	The Petroleum Institute, Department of Mechanical Engineering, PO Box 2533, Abu Dhabi, United Arab Emirates
URL	http://www.sciencedirect.com/science/article/pii/S0360544215017582
Volume	98
Pages	26-39
Publication	Energy
Date	March 1, 2016
Abstract	Hydrocarbon production fields are energy-intensive, with significant demands for on-site power, process heat and fresh water, particularly in arid climates. Researchers evaluated a poly-generation scheme based on the conversion of gas turbine exhaust thermal power into mechanical work to drive a seawater reverse osmosis unit and generate process heat in an off-shore oil field in the Arabian Gulf thermodynamically and economically. The prime mover exhaust thermal power was recovered using a bottoming organic Rankine cycle (ORC), with four working fluids used in commercial ORC systems evaluated. The performance of the poly-generation system was assessed both on a yearly and a seasonal basis. The octamethyltrisiloxane (MDM) cycle yields 6 MW of net power output at ideal and overall exhaust gas heat recovery efficiencies of 14% and 10%, respectively, 37 MW of process heat, and 1380 m3/hour of permeate. The reverse osmosis unit operates at a specific energy consumption and exergy efficiency of 4.1 kWh/m3 and 29%, respectively. The exergetic efficiency of the poly-generation system is estimated at 32%, thereby enhancing the efficiency of the original gas turbine power generation system by 6%. The system becomes profitable after approximately three years for subsidized local water and natural gas prices.