Cooling of vapour condensates
Cooling towers are both an environmental solution and an
important development for the industry
Industry players, in particular refineries and petrochemical
sites, have significant environmental challenges to address
Based in Normandy, the Total Petrochemicals France factory in
Gonfreville benefits from integration with the Normandy Total
refinery. The site produces the main petrochemical intermediaries
(ethylene, propylene, benzene, styrene, etc.) as well as polymers
(polyethylene, polypropylene and polystyrene), representing about
15% of mass-distributed plastics produced in France.
Operations managers were faced with an environmental challenge
in the summer of 2010. During a period of stoppage, the
petrochemical site discovered an excess of condensates after
ingress of vapours from the neighbouring refinery. The
excess condensates were peaking at as much as 50t/h.
What should be done with this excess?
The environmental temperature constraints did not allow the
excess hot condensates to be evacuated to the natural environment.
The engineers at Total Petrochemicals therefore contacted Aggreko
to devise and supply a temporary cooling solution as an alternative
to evacuating this excess.
Cooling Towers: An innovative solution, safe and quick to
Following an initial technical/economic feasibility study, the
Aggreko Process Services department, dedicated to petrochemical
applications, participated in an on-site Process workshop in order
to evaluate the project's technical and safety expectations.
Various technical solutions were presented. With an eye on
reducing the total cost of the operation and saving
energy, the Aggreko engineers designed a cooling tower solution 10
times more energy efficient than traditional technologies by
renting mechanical refrigeration. We therefore prioritised
evaporative technology to control the 4.4
MW of thermal charge created by cooling the condensates
from 100°C to 31°C.
The cooling tower solution was chosen to
respond to the temporary situation during equipment downtimes,
however the study did not stop there. During the study phase,
Aggreko Process Engineers, working together with the Total
Petrochemicals France team, proposed using "cold"
condensates in the network of cooling towers on the site.
Condensates are, of course, a source of recoverable water; by
injecting this water into the cooling network, the condensates are
recovered, lessening the environmental impact:
reducing waste, water samples taken and the quantity of treatment
One of the challenges for this recovery was the variable flow
rate of the condensates. Variations in flow could create a risk of
an excess of condensates, which is unacceptable for the
environment. Together with the engineers from Total Petrochemicals,
we developed a system of variable flow pumps
controlled by a level sensor calibrated to the millimetre (along
with a gravity-controlled overflow) to guarantee zero
Sabine H., Process Engineer, Total Petrochemicals France.
Faced with the temporary operating constraint encountered on the
site, the team from Aggreko offered us a solution which would meet
our specifications working to a very strict timeframe. We
appreciated the team's responsiveness and the strength of its
proposal in respecting the setup and operational constraints.
We were able to fulfil our 'no waste' objective thanks to the
mobile cooling solution which does not interfere with the operation
of the networks.