Binary Fluid Ejector

Binary Fluid Ejector

  • A BFE is a thermally-driven fluidic compressor that replaces the electro-mechanical compressor in reverse-Rankine thermal cycles (refrigeration cycles).
  • A BFE system essentially acts as a highly-efficient heat pump, and results in energy and economic savings.
  • BFE units can be driven by many types of low-grade thermal energy, including: solar thermal, geothermal, waste heat, stack flue gas, engine exhaust, biogas, biomass or natural gas and other fossil fuels.
  • BFE is a cross-cutting technology, applicable to a broad swath of applications in many economic sectors, including: air conditioning, space heating, water heating, refrigeration, industrial-scale desiccation, distillation and desalination, waste heat recovery and re-use, etc

The Technology
No high-performance, thermally driven heat pump or refrigeration cycle currently exists, though such a device would play a critical role in unlocking the wide spread use of renewable energy such as waste heat, solar thermal, and geothermal. Even in the absence of renewable energy, such a device would enable fuel switching from electricity to natural gas, which would save 65 to 75% on energy costs, reduce GHG production, and relieve the power grid during peak times. The Binary Fluid Ejector (BFE) has the potential to fill this important technology gap. Because refrigeration type thermal dynamic cycles cut across all sectors of the economy, the BFE is a platform technology with the potential for transformational impact on global energy use and the global water supply.
BFE is designed to replace the mechanical compressor used in traditional refrigeration systems. These thermal cycles consume billions of kWh of electric energy and produce hundreds of millions of metric tonnes of atmospheric carbon each year in North America. These traditional systems include space cooling (air conditioning), heat pumps (space heating), refrigerators (food storage, water chillers, etc.). Additionally, vapor recompression type thermal cycles are used for such important applications as distillation, desalination, and desiccation/drying systems.

The critical measure for energy efficiency for any refrigeration cycle or thermal cycles employing refrigeration is overall Coefficient of Performance (COP), defined as the work done over the energy consumed doing that work. For a reverse Rankine thermal cycle, for which the BFE qualifies, this translates into the energy efficiency of compression and expansion; BFE technology addresses the energy and cost efficiency of compression.
MRT’s Binary Fluid Ejector technology represents a new class of ejector that is self-consistent for binary fluid functionality. This means that the ejector does not simply employ a binary fluid, but rather, it is specifically designed for binary fluid operation; this design approach represents novel art. Unlike traditional ejectors that employ a single fluid, the use of a binary fluid allows for one fluid to optimize ejector efficiency, while the other optimizes refrigeration efficiency.


By no measure does BFE technology represent an incremental improvement over existing and emerging refrigeration cycles; because the BFE thermal cycle can be adapted to many applications, it represents a platform technology with the potential for transformational impact on global energy security and economies over a broad range of energy consuming sectors.
The BFE's low operating and capital costs could transform the economics for many applications using renewable energy. BFE can be driven by many forms of low grade thermal energy: waste heat, stack flue gas heat, solar thermal, geothermal, or biogas. When renewable energy is not available or intermittent (such as solar), natural gas (NG) or other fossil fuels may be combusted. Fuel choice can depend on emissions targets, price, or availability.

Although the fractionating condenser will be more expensive, the ejector itself is far less expensive than a conventional electromechanical compressor, equalizing or lowering BFE capital costs. A BFE should have much lower operational and maintenance costs, due to their solid state design, fuel options and energy efficiency. Heat exchangers represent additional capital cost for renewable BFE installations, but payback periods are shortened when the cost of the collector can be amortized over several functions. BFE can provide refrigeration, a/c, and hot water heating simultaneously or individually from the same collector. Expected payback periods should be acceptable to consumers.

A BFC should have higher energy performance than other thermally-driven technologies, resulting in smaller heat exchangers or collectors, and lower incremental capital costs for renewable installations. Due to their COP, NG-driven BFE units will show GHG reductions over similar electrical and natural gas driven appliances. Take air conditioning systems as an example. BFE is predicted to be far more efficient, and should save money on operating costs.