Organic Rankine Cycles (ORC) are systems that can effectively recover low-grade heat for electric power generation. For ORC to be a viable technology, it should operate safely and efficiently under variable operating conditions due to exogenous and operating specifications changes.

ORCs operate on low temperatures and low pressures with comparative to conventional Rankine Cycles. Therefore, organic fluids or refrigerants can be used as the working fluids for ORC applications, instead of water, which is more suitable for high-pressure and high-temperature applications.

Where heat pumps use electrical power to create thermal energy for various purposes, an ORC system uses heat energy to generate electricity. In a typical ORC design, a thermal energy source feeds an evaporator to drive an expander or “reverse compressor”, which in turn generates the electricity.

ASSOCIATED PETROLEUM GAS (APG) ORC is a viable technology that can use the energy content of flare gas to produce electric power. The heat recovery configuration involves a boiler fueled by flare gas that heats up a thermal vector fluid, typically thermal oil.