Tuesday, August 7, 2007

BP - Bad Petroleum

BP has been granted a permit to increase dumping in Lake Michigan at its Whiting oil refinery just south of Chicago.

The new dumping allowance:
Ammonia: 1584 lbs per day (54% increase)
Total Suspended Solids: 4925 lbs per day (35% increase)

The Whiting refinery has been getting upgrades to its equipment to allow refining of sour crude oil into gasoline, diesel, jet fuel, asphalt etc. The plant expects the upgraded equipment to be operating at full capacity sometime in 2008. BP is making the upgrades because sour crude oil extracted from tar sands is becoming more abundant, while availability of light sweet crude is falling off.

Bituminous Sands

Bituminous sands (oil sand) are a mixture of water, clay, sand and heavy crude oil. The mix can be around 90% water and mud from which a relatively small amount of low quality heavy crude can be extracted. Conventional oil wells can basically be drilled and tapped. The pressure in the oil fields itself provides the energy to push the oil to the surface for most of the lifetime of the well. Oil sands require much more energy and materials to process. The sands are either extracted by strip mining or processed in place with huge amounts of water and caustic chemicals to separate the hydrocarbons from inorganic wastes. Steam pipes can also be sunk into the oil sand ranges to liquefy the sands for easier pumping and separation, which requires massive steam generators and fresh water. Strip mined sands are loaded by the largest shovels ever made into the largest trucks ever made and moved to separator tanks and mixed with water and sodium hydroxide (lye). Crude oil is skimmed off the top of the separator tanks and the remaining sediments are allowed to settle. This consumes large amounts of energy and water, and produces tons of waste chemicals and sludge. I imagine some of the water and lye is reclaimed and reused in the separator tanks to save costs, but its probably easier and maybe cheaper to dump the wastes and sediments in mixing pools, where they are mixed and diluted with more fresh water and drained back into the water table via wetlands. Only about 80% of the water is currently reused.
Only about 20% of Canada's oil sands can be extracted by strip mining. The rest are too far below the surface and require alternate methods. Cold flow pumping uses progressive cavity pumps (a huge motorized screw in a elliptical cavity) to simply pump the oil up and through sand filters. This only works where the oil is viscous enough to flow through pumps and surrounding sediments. This allows ~5-8% of the oil in deep deposits to be recovered. Removing the sand filters allows the pumps to create 'wormholes' in the sand deposits, which allows slightly better extraction, but disposing of the sand is a problem. The Canadian government allowed oil companies to spread the oily sand on dirt roads for a while, but the road surfaces started getting so thick that this solution stopped being viable. You only have so many rural roads to pave. Various other methods combine pumping with steam injection, with higher recovery rates of around 20%, but eventually producing the amount of steam needed costs more than the oil being recovered. There is actually an ongoing project to use nuclear energy to produce steam for oil recovery in Canada. Ahh.. Er..

Surface Oil Extraction

Canada's oil sands are situated under boreal forests and peat bogs. The companies licensing this land for strip mining are required to implement recovery plans for these forests. Somehow the oil companies got away with the plan to let the boreal forests recover themselves. Their idea was that the forests would repopulate the recovered areas naturally. None of the 33,000 hectares that has been leveled has been certified as reclaimed.

Satellite image of the Syncrude oil sands processing facility in Northern Alberta. Zoom out to see the surrounding surface mining areas:

Syncrude facility, Alberta, Canada

Sour crude contains more carbon dioxide and sulphur/hydrogen compounds (mercaptans). This makes it more difficult to refine into what BP claims is 'cleaner fuel'. Some mercaptans (or thiols, compounds in the sulfhydryl group) are added to natural gas to make it smell bad for detectability. Most of the compounds in this group are waste products of refining crude.

Whiting Refinery

Anyone in any of the south shore refinery cities knows the odor of refinery waste. Driving through the area is pretty bad, but imagine living across the street. Mercaptans smell powerfully like rotten eggs. The vapors will give you headaches, make you dizzy and sometimes cause vomiting. Long term exposure causes liver and kidney damage. Another property of mercaptans is that they like to bind tightly to the element mercury. The term mercaptan comes from the Latin mercurius captans, which means 'laying hold of mercury'. Water removed from crude oil contains hydrogen sulphides and ammonia impurities which need to be steam stripped and cooled before dumping back into the water table. Steam stripping sour water doesn't remove all of the ammonia, hydrogen sulphides or sulfhydryl-mercury compounds. The steam stripped water is mixed with fresh water from Lake Michigan in mixing pools, where it is allowed to cool before being released back into the lake.

In an internal email, BP's chief says that the waste water mixed back into Lake Michigan is 99.9% pure. So, one part per thousand is contaminated. When it comes to water quality, that is a huge amount of contamination. So ~5000 lbs of suspended solids (various mercaptans, etc) and ~1600 lbs of ammonia is 1/1000th of a bit more than half a million pounds, or 80,000 gallons of water per day.

80,000 gallons of warm, ammonia, nitrogen and sulfhydryl rich water per day, 30 million gallons per year. Along with it goes 2lbs of mercury and other heavy metals that can't be filtered out with current technology. Increased nitrogen leads to algae blooms and dead zones, which kills off fish and then birds and other wildlife that depend on clean, clear water. The USGS lists lakes Michigan, Erie, Huron and Ontario in mixed or deteriorating conditions.

BP's Whiting Facility. Located at the top on the shore is the cooling, mixing and waste water pumping station:

BP Petroleum, Whiting IN

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