The project involved a large agri-business which processed vegetable oil into fractionations for use in the food industry. The company used approximately €1.54 million in natural gas for steam generation annually. It had an old plant which was continually in operation and difficult to maintain due to process restrictions. The company tasked CoolPlanet with improving energy efficiency.
The main user of low-pressure steam was a solvent process which using 35% more steam than required for the process. Not much instrumentation was available to see the cause or effect of problems. It was clear from open bypass valves that traps were an issue, and from condensate vessel overflow that a lot of condensate was going to drain and wasting energy. Safety valves were allowing steam to escape to atmosphere and many areas of insulation and pipework were in bad condition.
The reboiler on site was not operating effectively and wasting steam and maintenance was poor on steam traps. A variety of steam traps were being used but these were mainly older, less efficient designs. Where newer, more efficient traps were installed, they were installed incorrectly leading to issues. Some valves were passing and could not be closed fully. Finally, the maintenance budget was consistently high to deal with replacement of traps.
An investment grade audit identified savings around compressed air, refrigeration, and a number of thermal solutions. CoolPlanet worked with the agribusiness to understand maintenance and operation issues. Full steam and condensate audits were carried out, including infrared and ultrasonic testing of steam traps.
CoolPlanet also plugged its CoolPlanetOS technology into the site’s existing SCADA system to harness and analyse the plant’s data. Through an in-depth analysis via CoolPlanetOS, the system was modelled for heat use.
A total of 377 steam traps were replaced. Each trap was installed with appropriate strainer and blowdown valve. A number of leaking valves were also replaced. Insulation was repaired and replaced, and valve mats and mattresses were installed. A safety valve and steam trap were replaced on the reboiler.
A program was set up for cleaning the steam system of built up foreign material and leaking material. A second program was set up for regular blowdown and preventative maintenance/testing of the steam traps.
Optimal energy efficiency led to better performance of the plant, with improved KPIs for product per tonne of material. The improved energy efficiency also led a safer work environment due to no steam leaks of hot water dropping and better control of utilities. CoolPlanetOS is continuously monitoring the system to ensure that the increased energy efficiency remains a constant.
A reduction in steam usage led to annual energy savings of €293,000, while a further €57,000 in savings were created through reduced spend on maintenance.
In terms of capital expenditure (CAPEX), the payback of the improvements made by CoolPlanet is estimated at 3 years.