This is a series of similar heat recovery projects framed in the combined heat and power plants of a company dedicated to the extraction of soybean and sunflower oils for the food industry, the generation of biodiesel and the production of animal feed. This company has three production facilities in Spain, located in Cartagena, Bilbao and Barcelona. The cogeneration facilities date back to the 2000s and are based on the generation of electricity from Rolls-Royce engines and the use of heat to generate medium-pressure steam by means of fire tube recovery boilers.

This series of heat recovery projects carried out by AITESA started with a pilot project at a facility in Cartagena in 2013. The existing cogeneration system for the Soybean and Sunflower circuits operated with a chimney flue gas outlet temperature of about 210ºC. Together with the available gas flow, sufficient energy was available to consider an additional heat recovery unit through the installation of a water-tube recovery boiler to generate low-pressure steam, and thus improve the overall performance of the plant processes that require this type of steam. Finally, between 2013 and 2016, a total of 5 recovery boilers were installed, 2 in Cartagena, 2 in Bilbao and 1 in Barcelona. Each project was executed on a turnkey basis, including all the instrumentation, control and communication with the existing steam and cogeneration network. The 5 boilers each generate approximately 2 Ton/h of steam at 2 bar(g) pressure, to be used in plant processes such as seed preparation or oil extraction.

The recovery boilers allow additional steam generation enabling load flexibility of the conventional boilers used for steam generation, and in this way to improve the global efficiency of the production processes.