Patented technology will aid in future oil spill recovery

oil separation
In light of the recent BP oil spill in the Gulf of Mexico—20 years after the Exxon Valdez disaster in Alaska—we still have no effective technology for removing, recovering, and cleaning up oil spills or oil slicks from the surface of sea water and shorelines. Despite the government’s "all hands on deck" approach to combating the Gulf oil spill, most of the methods used are decades old, decidedly low tech, manpower intensive methods, some with unknown environmental consequences. Oil spill accidents around the world are actually more frequent than the few highly publicized cases in United States. Every few years there has been a major oil spill, due to storage tanks and pipes cracking, oil tanker collisions or wrecks, even from the war with delivery destroying oil facilities. The Exxon Valdez spilled 11 million gallons oil into the Prince William Sound, but even that did not make the top ten list of the largest oil spills (the smallest spill on the list was four times larger than that of Exxon Valdez). Indeed, 33 oil spills were measured as larger and more devastating in the past 40 years.
 
Three standard methods are commonly deployed to combat an oil spill on the open sea today, which have stayed similar for many decades since the oil exploration in deep waters. The first tactic is the so-called mechanical approach, which comprises of a boom to corral and deflect oil and skimmers to collect it. It is a preferred approach because it's the only one that takes the oil out of the environment. However, this method is labor intensive and equipment intensive operation with low yield. It was estimated by the Coast Guard that only about 10 percent of the BP’s oil was removed by mechanical recovery. The second approach is to apply dispersants to the oil slick. These detergent like solvents are typically deployed from sea vessels operating around the slick, or from aircrafts overhead. Additionally, BP applied dispersants below sea level using robotic submarines. When dispersants mix with the slick, they break up the oil into droplets, suspending them in the water column to be dealt with naturally. The decision to use 42 million gallons of dispersants in the Gulf amounted to an environmental trade-off; it meant less oil tainting the surface, where there is noticeable, active natural life, but with the risks of longer-term problems down below the surface. The final tactic being deployed in the Gulf is in situ burning. Oil is corralled using booms to thickness where enough volatiles are present to sustain a controlled burn. Once the oil is burned it forms a tar like substance that can either be manually removed from the water, or left to decompose naturally, similar to dispersant treated oil. Oftentimes, unfavorably strong winds and rough seas have prevented in situ burning.
 
Based on the current methods, most of the spilled oils are wasted, becoming pollutants in our air and waters. Small fractions that are actually recovered, in fact, generate a large quantity of solid and liquid wastes themselves, from tons of soiled boom and other oily waste. About 40,000 tons of solid waste and more than 7.7 million gallons of oily liquid waste have been collected in the BP oil spill. They are treated as industrial waste, and by law they are allowed to be buried at specially designated dumps, some near residential neighborhoods. However, many residents raised concerns about the magnitude and safety of the oil spill waste being buried nearby and have been preventative with oil dumpings in their community.
 
There have been some technologies (several shown in YouTube) reporting the absorption of the spilled oils with inorganic mineral products (i.e. clay, silica, zeolites, etc.) and organic vegetable products (straw, corn corb, peat moss, wood fiber, cotton fiber, etc.). Most of them show limited oil absorption capacity and also absorb water; therefore the oil absorbers that are recovered are unsuitable for calcination. Several synthetic fibers, such as meltbrown PP pads and booms, have also been known; they absorb oil in their interstices by capillary action. Because the weak oil substrate interaction (adsorption mechanism), the fiber based absorbers exhibit many disadvantages, including failure to maintain oil of low viscosity, easy re-bleeding of the absorbed oil under a slight external force. There are also some patents disclosing the usage of synthetic resins, such as cross-linked styrenic and acrylic copolymers. However, they have the drawback of a long absorbing time, especially for aliphatic hydrocarbon components. Some methods, i.e. milling the oil absorber to increase surface area, were applied to improve the oil absorbing speed. However, the light cross linked granules are subjected to dissolution in oil (difficult for recovery), and the heavily cross linked granules show limited oil absorption capacity. In addition, the milled oil absorbers are liable to aggregate, thereby the gel block phenomenon prevents the admission of oil to be absorbed into further gaps between the particles of oil absorber. Furthermore, it is always a major concern on the treatment of the recovered solid materials, including waste disposal, recyclability, and biodegradability issues.
 

New Petro-SAP Developed at Penn State: 

At Penn State University, we have developed and patented a new polyolefin-based petroleum super-absorbent (Petro-SAP) that can effectively transform a maritime oil spill into a floating solid, ready for collection (recovery) and refining as regular crude oil (no waste in natural resources and no disposal issues). Figure 1 shows a ½" sized Petro-SAP sample increase its weight by more than 10 times within 10 minutes, and reaching 40 times after 12 hours, after coming to contact with crude oil that contains linear, cyclic, and aromatic hydrocarbons with low and high molecular weights. Its speed and capacity of oil absorption are superior, compared to that of currently-available oil absorbers. The resulting oil swelled Petro-SAP solid is floating on the water surface and can be picked up with a tweezer, without leaking oil. The combination of good mechanical strength and strong oil affinity assure its structure integrity, it shall be stable under ocean environments (waves, wind, sunlight, etc.) and removal from the water surface.
 
If this material would be applied directly on the top of the leaking well head in the Gulf of Mexico, the Petro-SAP could effectively transform the gushing brown oil into a floating gel for collection; it would hold and stop fresh oil from polluting the waters and air. It could also be used for cleanup to selectively remove oil slicks from the surface of oceans and shorelines. In light of current refining technology for heavy oils and bitumens (oil sands), the recovered oil/Petro-SAP mixture (without water) should be suitable in the regular oil refining process (distillation and cracking). The mixtures have almost the same composition of original crude oil, with a minor amount of polyolefin (a petroleum downstream product) that may be decomposed or became asphalt residue during refinery. In other words, there is no waste on natural resources (no burning and no waste disposal problems).
 
 
Furthermore, polyolefin products are the most inexpensive polymeric materials, with a large production capability in the United States and around the world. With conservative estimate, the production cost of new Petro-SAP material may be below $2 per pound in the large-scale industrial production. One pound of oil-SAP with 40 times absorption capacity can recover more than 5 gallons of the spilled oil (currently treated as pollutants and wastes) to regular crude oil that is worth more than $12 (based on $80/barrel). For the 1.5-2.5 million gallons of oil leaking every day in the Gulf of Mexico (government estimation), it may only cost between $600,000 and $1,000,000 per day to use polyolefin Petro-SAP material to recover all the spilled oils; the recovered oil would be worth between $3.6 and $6 million.
 
Overall, this new polyolefin-based Petro-SAP material exhibits a combination of benefits in oil recovery and cleanup, including (i) high oil absorption capability, (ii) fast kinetics, (iii) easy recovery from water surface, (iv) no water absorption, (v) no waste in natural resources, and (vi) cost effective and economic feasible.