Chemical treatments against biofouling on industrial equipment associated with marine related power generation technologies, a new approach to an old problem

Biofouling is a problem well known to manufacturers and researchers in various fields of knowledge (i.e. heat transfer, marine engineering, desalination of sea water and the offshore industry. One of the deepest impacts, both economic and operational, is on industrial equipment that uses sea water for cooling purposes, this is associated with power generation technologies; and can include loss of the equipment's design parameters, implications regarding total loss of efficiency and an increase in unscheduled maintenance actions, both corrective and preventative, that are established in the operation and maintenance (O&M) plans adopted by industries in which this type of technology is used. The procedures used in the struggle and control against biofouling on industrial equipment associated to marine related power generation facilities have been widely researched in regions such as the Persian Gulf, the Caribbean Sea and the Far East, but not yet in any other areas where climate conditions differ from the ones cited. In order to control and eliminate the above phenomena, two main strategies to fight against biofouling have been developed in recent decades; physical treatment and chemical treatment. The present research has developed treatment of a chemical nature by applying two different chemical compounds (chain quaternary ammonium and propylene glycol), both of which are environmentally friendly. The use of quaternary ammonium compounds (QAC) had not been researched enough at the time that the investigation into biofouling and propylene glycol was carried out, and had never been tested on this type of equipment. The research undertaken aims to clarify which compound is capable of eliminating biofouling and return the conditions of the exchanger tube back to those of the clean tube, and to find out what dosage should be applied to maintain these conditions over a long period of time. The experiment was conducted on two different physical surfaces, AISI316Ti and AISI316L in a pilot plant located at the Nautical School of the University of Cantabria (Spain), under the supervision of the Department of Science and Technology of Navigation and Marine Construction. A toxicological study has also been carried out on fish (Scophthalthmus Máximus) in accordance with the directive of the Paris Commission (PARCOM) with the purpose of verifying that each chemical compound used was not harmful to the marine environment.