HELLENiQ ENERGY

The main goal is the effective management and utilization of the oily refinery wastes. The utilization poses environmental and economic benefit, which arise from the re-refining of the organic phase, the reuse of the aqueous phase and the inertization of the solid residue and its use as a non-hazardous or an inert material.

Technicians/engineers/scientists dealing with waste management and resource recovery.

2000 - up to date

This integrated waste management method that is applied to oily wastes, is based on a two-step treatment system. The two stages are:

1. The tricanter unit, which consists of a three-phase centrifuge system that separates:
a. The oil phase is being further refined, thus saving resources,
b. The liquid-aqueous phase which is being further treated in the wastewater (three-stage) treatment plant of refinery,
c. the solid phase (oily sludge) which is the feed of the bioremediation unit.

2. The bioremediation unit. Bioremediation unit is based on the technique of engineered bioventing using biopiles, and it is applied to many facilities in the European area, both for contaminated soils and oily sludge. This technique aims to eliminate hydrocarbons concentration, by the physical aerobic biodegradation of organic pollutants carried by the microorganisms which are present in soil or mud.

Radical acceleration of biological processes can be achieved by optimizing the growth conditions of aerobic microorganisms, through the control of oxygen, water and nutrients. The end product of the process is thoroughly checked in order to be landfilled or to be used in earthworks, through specific leaching tests and chemical analyses carried out by accredited laboratory, as specified in the Council Decision 2003/33/EC “establishing criteria and procedures for the acceptance of waste at landfills pursuant to Article 16 of and Annex II to Directive 1999/31/EC". Liquid and gaseous emissions in bioremediation unit are fully controlled using activated carbon filters for air emissions, while waste waters (leachate) are being treated appropriately.

INTERGEO Environmental Technology ltd

All the employees of HSE and Quality Division of Thessaloniki Industrial Complex and Group HSE and Sustainable Development were actively participated in all phases of the project (design, operation and monitoring).

Thessaloniki Industrial Complex

The results of this action are mainly related to environmental protection and resources utilization. Resources would otherwise be driven to disposal, with the consequent negative impact on the environment and society.

Regarding environmental protection, this is related to the following points:

• The end product of the treatment meets the disposal requirements for landfills or can be alternatively used as inert material in earthworks.
• The recovered oil from the centrifugation stage is normally mixed with crude oil as feed of the atmospheric distillation unit, contributing to significant cost savings.
• It’s a low energy technique and the consumption of other natural resources (e.g. water) is limited.
• By the use of this technique, incineration is avoided as a possible alternative method of treatment.
• There are no emissions to the atmosphere, as an air suction device with a activated carbon filter is applied but despite that, concentrations of CO2, O2, VOC (Volatile Organic Compounds) upstream the filter are monitored in order to check the progress of the bioremediation process.
• Leachates resulting from the application of the method are treated in the wastewater treatment plant so there is no additional pollution to the aquifer or the soil.

Finally, it has to be noted that the project and the obtained results were presented during the Second International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE 09), published in a peer review scientific journal (Antonios Mountouris et al, 2011, Biotreatment of oil refinery sludge, Desalination and Water Treatment, 33: 1-3, 194-201) and awarded in Environmental Awards 2014 (Silver Award, Category Waste Management / Resource Recovery). Moreover, the obtained results were submitted and taken into consideration during the recent revision of BAT for the oil refining industry (Best Available Techniques -BAT - Reference Document for the Refining of Mineral Oil and Gas).

The benefits for Hellenic Petroleum are:

Financial:

• The recovered oil from the centrifugation stage is normally mixed with crude oil as feed of the atmospheric distillation unit, contributing to significant cost savings. The percentage of the oily phase that is being re-refined is of the order of 38% of the total quantities processed in the unit.
• Reduced cost of solid waste management which is around 250€ per ton of waste lower compared to alternative disposal methods.

Environmental:

• The end product of the treatment meets the requirements for disposal in landfills or can be alternatively used as inert material in earthworks. The average concentration of DOC (Dissolved Organic Carbon), before treatment ranged was 1.450 mg/Kg., while final DOC concentrations achieved before final disposal ranged from 55 to 135 mg/Kg, which is far below and the threshold established by the relevant Council Decision on disposal of wastes (500 mg/Kg).
• It’s a low energy technique and the consumption of other natural resources is limited.
• Zero emissions to atmosphere as an air suction device is applied and even before the activated carbon filter, concentrations of CO2, O2, VOC (Volatile Organic Compounds) are monitored in order to check the progress of the bioremediation process.
• Leachates resulting from the application of the method are treated in the wastewater treatment plant so there is no additional pollution to the aquifer or the soil. Effluents characteristics are thoroughly checked before final disposal and they are at least 50% lower than the legislative limits.