Are ORCs a Good Option for Waste Heat Recovery in a Petroleum Refinery?

Authors : Bruno Mazetto, Julio Silva, Silvio Junior

Pages : 161-169

Doi:10.5541/ijot.5000070476

View : 12 | Download : 8

Publication Date : 2015-08-06

Article Type : Research

Abstract :The studies regarding Organic Rankine Cycles (ORCs) have been intensified due to the capacity of these systems to convert low-grade energy sources such as geothermal, solar and industrial waste heat into electricity. In this work optimized configurations of ORCs are compared with conventional options of industrial waste heat recovery such as preheating of boiler feed water and cooling of the gas turbine inlet air using an absorption chiller. The study was focused on the recovery of thermal exergy of a diesel stream in a typical petroleum refinery. Several organic working fluids were tested. The cycle parameters were optimized for each working fluid using two different objective functions: to maximize net power output and to maximize the power to area ratio. R134a was the organic fluid that generated maximum power output (~940 kW) while water was the fluid that generated maximum power to area ratio (~650 W/m2). The comparison of these optimized configurations with other alternatives of heat recovery shows that the gas turbine inlet air cooling coupled with boiler feed water preheating is the best option to increase overall net power output and efficiency. The ORCs were the last option for the analyzed conditions.
Keywords : ORC, refinery, heat recover, processes integration, power generation