Befesa - Presse



The adopting of alternative technology minimizes risks, enhances working conditions, reduces stoppage times and improves environmental indicators in refinery distillation tower cleaning processes

Four of the fundamental enhancement aspects applied to cleaning and maintenance projects for large process installations are the minimization of potential environmental impacts, mitigation of risks associated with the operation, enhancement and automation of personnel working conditions and reduction of installation stoppage time.

Befesa Gestión de Residuos’ Cleaning Division is working constantly on the design and adoption of practices that contribute to advancement in these four areas. As a result thereof, over the past few years, systems that have allowed our customers to achieve the four enhancement objectives have been implemented. Three specific examples are the automated tank cleaning technology (described in our previous newsletter), which minimizes the volume of generated wastes and the works to be performed by personnel under confined-space conditions, the enhancement of catalyst jigging processes to enable a higher recycling rate, and the utilization of extremely-high-pressure cleaning techniques that reduce effluent generated in equipment cleaning processes.

In 2006, in line with these improvements, a crude oil distillation tower cleaning project was completed at a refinery. The project allowed, through the application of specific chemical products, the decontamination of said equipment while also enabling minimum personnel operating periods inside the equipment under much more favorable working conditions due to the absence of contaminants. Another advantage was that the method employed greatly reduced the generation of wastes in comparison to traditional methods.

The project was executed at one of the largest refineries in Spain through an alliance with the North American company Baker Hughes.

The work consisted of the applying of an additive provided by Baker Hughes, utilizing a closed circuit that allowed the product to re-circulate at a temperature of 95ºC over a period of approximately 24 hours. The technical experts from Baker Hughes and Befesa’s Tarragona office conducted an advance study to design the provisional circuits that were to be installed in the equipment, as well as the necessary accessories and ancillary operations. The project was supervised "on-site" by the experts from both companies under a 24-hour working regime.

The table below shows a comparison between the applied process and traditional methods:

Comparison crude-oil distilation tower cleaning project
Comparison crude-oil distilation tower cleaning project
 Traditional methodProject
Tower diameter (m)5.225.22
Tower height (m)49.7849.78
Circuit's estimated volumen (m3)1064.00200.00
Number of plates4343
Initial estimated volume of siop oil (m3)200.00200.00
Estimated cleaning time (hours)20050
Vinal volume of siop oil to be treated (m3)150.0015.00
Final aqueous waste (m3)450.00500.00
Amount of reactant used (m3)---3,00
Man/hours confined space (hours)60050

As the above table clearly demonstrates, there is considerable improvement in the four aforementioned areas and stoppage time is reduced by more than 70% and there is more than 90% improvement in the other two numerical indicators: man/hours in confined space and final volume of generated wastes. The minimization of associated risks, although not parameterized, is clear to be seen in the reduction in man/hours in confined space and this is, perhaps, the greatest benefit to be attained from this technique.

The process can be applied to clean circuits, tanks, exchangers and towers in the petrochemical sector. Befesa GRI and Baker Hughes are currently considering applying the process for other customers, by operating as the providers of a turnkey solution.