Pressure letdowns represent another source of waste energy on many industrial sites. Through innovative applications of proven technology, Genalta Power can generate electricity from gas or liquid pressure letdowns.

Pressure control valves are used to reIn any process where gas or liquid goes from a high pressure to a low pressure, this pressure drop is controlled using a pressure control valve. Genalta Power can bypass this pressure control valve to generate power using a hydraulic power recovery turbine or turbo-expander. In the case of a gas, additional pre-heat is required due to the cooling effect of the pressure drop. Sour gas plants are a very good example of liquid pressure drop, where the amine stream that is used to strip the H2S has a pressure drop across the absorber tower with a pressure control valve at the bottom.

Electricity can be generated by capturing liquid pressure and/or gas vapour flow energy. A practical example of this is where energy is extracted from falling water to run a turbine to generate electric power (e.g. hydro), but there are many other sources, such as:

  • Throttling valves used to drop the pressure of liquids (such as rich amine in natural gas processing or the manufacture of ammonia).
  • Throttling valves used to drop the pressure of gasses (such as ethane in the polyethylene production process).
  • Pressure from produced water when it is brought to the surface for processing and then re-injected into the well during oil production.
  • Flow or pressure control valves in municipal water and natural gas distribution systems.
  • Transmission to distribution natural gas pipelines where the pressure is reduced for natural gas distribution to cities, commercial clients or industrial facilities.
  • Pressure from the rejected concentrate stream of reverse osmosis systems used to desalinate water.
  • Cooling water inlets or outlets to large power plants.

By utilizing the waste pressure energy from liquid or gas streams, the Genalta Energy Management (GEM) ™ System converts waste energy into mechanical power to generate electricity that can either be used at the facility or sold to the electric power grid. This form of electrical power generation is typically referred to as environmentally friendly, distributed power generation; meaning the waste pressure to power projects produce electricity with zero net emissions, supporting the energy policies of governments for the development of electricity generation projects using clean or renewable resources.