Microwave cleaning of oils
Much as a conventional machine drill requires lubrication and generates small pieces of metal, drilling for oil and gas requires lubrication with a viscous oil and water emulsion known as drilling mud. In addition, the process produces drill cuttings (DCs) or fragments of rock. These are contaminated with the drilling mud and must be treated. The disposal of drilling mud and DCs is facing increasingly stringent environmental restrictions on oil content (OC), restrictions that affect oil containing hazardous waste in landfills as well. In western Europe alone, there are more than 600 000 contaminated sites. Cost-effective solutions to this growing problem are urgently needed, providing the impetus for the EU-funded project 'Microwave cleaning of drilling mud and oil containing hazardous waste' (MICROCLEANMUD). Scientists developed an MW-assisted cleaning system to recycle organic oil from DCs produced by offshore drilling and to decontaminate soil for the soil remediation sector. The system incorporates special MW absorbers in the reactor chambers to significantly lower power consumption. Laboratory tests demonstrated the ability of the feeding system, reactor chambers and control system to reduce the OC of DCs to the required 0.1 %. Additional optimisation will be focused on further simplifying the design to lower costs. MICROCLEANMUD MW treatment technology to reduce OC in DCs and in landfills is expected to have important impact on European hazardous waste management and on the sustainability of oil and gas exploration and production.
