Improved Separator Design through Dense Packed Layer (DPL) Extraction and Treatment

Separation of dispersions is a necessity in many industries in which commercial products are extracted from an emulsion i.e. crude oil with water, biodiesel with glycerol, etc. The rate of separation depends on the concentration and the properties of surface-active components (SACs) (asphaltenes, resins, naphthenic acid materials, and oil-soluble organic acids), droplet size distribution, and separation methods. IMPOSE project has developed methods/techniques to characterize SAC and also to measure the droplet size distribution in real-time. To characterize surface-active components (SACs) in a crude oil system, SINTEF has collaborated with the Max-Planck Institute (MPI). MPI has used state-of-the-art FT-ICR Mass Spectroscopy devices to characterize SACs in crude oil from the Norwegian continental shelf such as Grane, Oseberg Øst, Gjøa, Brage, etc. These studies provided an important insight into the crude oil-water emulsion system. The FT-ICR MS Spectroscopy was specifically included and used in the ESI (-ve) mode to closely decipher acidic groups in crude oil samples. Acidic groups typically are most surface active and alongside asphaltenes and waxes are the fundamental cause of emulsion stability. Using this acidity and molecular spread of various acidic groups could be mapped the overall structure of SAC. Through a meticulously planned research activity during the IMPOSE project, SINTEF has come up with a new device that can measure the droplet size distribution in real-time. The developed device system is a combination of a carefully designed microscopy laser probe that takes images of flowing emulsion. These images that are collected in computer systems are instantly transferred to a GPU system where they are processed to detect droplets. Using artificial intelligence, the droplet size distribution is estimated from images. This droplet size distribution continuously appears on the computer user interface screen where the prevailing system can be monitored. One of the objectives of the IMPOSE project was to develop environmentally friendly methods to separate the oil from the crude-water oil emulsion. The IMPOSE project has tested several separation techniques i.e. microwave heating, centrifuge, thermal heating, and electrocoalescence. Although electrocoalescence was the most efficient method for emulsion separation, the existing electrocoalescence technologies are not optimized for crude oil water. During the IMPOSE project, we have developed beyond the state of the electrocoalescence techniques/devices which can destabilize an emulsion within 2 hours, which normally takes more than one day to separate using a gravity separator. Nanotechnology is widely recognized for having important applications in many industries including oil and gas. Both environmental and cost benefits can be achieved when using nanoparticles for the separation of water and oil or for further purification of produced water. An efficient emulsion separation can be achieved by selective adsorption of naturally present stabilizing components and removing nanoparticle-tagged droplets with the help of a magnetic field. The IMPOSE project has been testing the use of nanoparticles (NPs) for oil-water separation. A review paper on the application of nanotechnology for asphaltene adsorption and crude oil demulsification was published. Many studies on the use of NPs performed during the IMPOSE project showed that NPs with high surface areas adsorb asphaltenes efficiently, which leads to an efficient oil-water separation.

The project, directly and indirectly, contributed to the following impacts Economical impact: As of today, the industry faces serious challenges in the choice of separation methods and they are unable to decide which de-emulsification method or combination of de-emulsification methods should be used for efficient separation. The most common methods in the oil industry for the separation of W/O emulsions are the use of demulsifiers, thermal and microwave heating, and an electrostatic treatment. The conventional heat treatment is limited by the temperature of the surface and the physical properties of the emulsion being heated. Microwave heating treatment is restricted due to the complex interaction of surface-active compounds with oil and water. The excessive use of chemical demulsifiers not only causes monetary losses but also environmental issues. Most of the profits and cost reductions for petroleum industries will come by accelerating the separation process and by reducing the amount of chemicals used for separation. IMPOSE has developed a state-of-the-art separation technique based on electrocoalescence. Based on our lab study, this electrocoalescence technique destabilizes an emulsion within 2 hours, which normally takes more than one day to separate using a gravity separator. This will eventually lead to cost reduction incurred during the separation process. Environmental impacts: During the separation process excessive amount of demulsifiers are used. Although demulsifiers are very effective, environmentally unfriendly, expensive, and nonrecyclable. The use of nanoparticles (NPs) for emulsion destabilization, tested during the IMPOSE project, is cost-effective and environmentally friendly. These NPs are easy to recycle with minimum energy consumption. Scientific impact: The IMPOSE project findings have been published in high-impact peer-reviewed journals and have been presented at high-visibility international conferences. The project has contributed to the following outcomes 1) Cheaper and reliable microscopic probe: The available microscopic probe for droplet detection on the market cost around 1 million Norwegian kroner. The probe developed during the IMPOSE project cost around 200 thousand kroner. However, the IMPOSE probes have been tested at TRL 5 and need to be tested at TRL 7 before commercialization. 2) Faster and real-time software for estimating droplet size distributions: The existing software for estimating the droplet size distribution in the flowing emulsions does not provide information in real-time. During the IMPOSE project, we developed software on a deep learning-based neural networking method (Faster R-CNN). This software is much faster providing information in real-time on the display system attached to the probe. 3) Nanoparticles-based emulsifier 4) Improve electrocoalescence design 5) Educating 10 bachelor's students, 4 international exchange students, and 6 summer interns during the project

Traditionally separators are large due to constraint on residence time. As per today, the industry faces serious challenges on the choice of separation methods and they are unable to decide which de-emulsification method or combination of de-emulsification methods should be used for efficient separation. The most common methods in the oil industry for the separation of W/O emulsions are use of demulsifiers, thermal and microwave heating and an electrostatic treatment. In the project a state of art stirred tank separator with inbuilt emulsion characterization technique is proposed. This separator cell will be equipped with chemical injection for de-emulsifiers and gas-pressurization to mimic the reality. Besides, thermal heating, microwave heating, and electric field will be designed, fabricated and implemented into the tank cell giving the system a multi-dimensional analysis capacity. Further a range of measurement accessories will be utilized to accurately measure emulsion dynamics or relaxation timescales for droplet coalescence. This advanced bottle test can be utilized by oil industry to develop operation regime map for optimized dissipation A method will be designed on the efficient removal of asphaltene and resins from the emulsion. We further propose that it is necessary to process DPL separately after it comes out of the separator. The reason being simply that the DPL is in need of a different processing strategy relative to the raw crude O/W emulsion. This diagnosis will be done in the stirred tank cell and appropriate operation strategy will be devised for the DPL. Thus a research-based understanding is derived to diagnose and troubleshoot separation. Further, stability parametric models will be developed that can be implemented in simulation software. Assuming that the entire research and technology development is successful, parameterization of surface chemistry will support scaling up and optimize modelling of DPL in industrial scale separation.