Chinese researchers have identified a catalyst called NiMoW, for the hydrotreating of the refined diesel distillate fraction from the Fushun shale oil deposit.
Shale oil has high levels of nitrogen, sulfur, and unsaturated hydrocarbons, limiting its potential use to supplant or replace crude oil. Coming up with economical cleaning systems would get shale oil more competitive.
There is a lot of shale oil out there. Using a the Fischer Assay, which yields a heating value, across the planet’s known reserves turns up numbers like 3.3 billion tons with 2.8 billion, more than 78% in the U.S. Most of that is in the Green River Formation out in Colorado. It’s a huge reserve. No other known reserve exceeds 20% of the Green River deposit and most come in under 10%. Not that those others are small, the Green River deposit very conservatively holds more than 200 years of U.S. needs at current use rates.
Close-up of fractured oil shale specimen from the Uinta Basin, Utah, showing weathered (white) and unweathered (black) surfaces. Photo courtesy of Argonne National Laboratory.
The first problem is that shale oil is actually kerosene. Kerogen is a mixture of organic chemical compounds with the soluble portion is known as bitumen, the stuff of the Canadian Oil Sands. Not all of the organic chemicals come up as bitumen. The problem is what’s missing – hydrogen. Kerogen is carbon rich, but hydrogen poor.
Extraction then is quite costly and energy intensive. Heat is needed to raise the viscosity and the heat would be applied to the rock that contains the kerogen. Lots of heat is needed. Then the kerogen needs refined and cleaned. Adding solvents or adding back hydrogen can improve the oil product results.
Some processing methods yield considerably more useful product than the Fischer Assay would indicate. The Tosco II method yields over 100% more oil, and the Hytort process yields between 300% to 400% more oil. There could be an enormous supply of petroleum products if the extraction, hydrogen enrichment and cleaning problems get solved. All it takes is ingenuity and money in a high enough crude oil price environment to get investment on board.
The use of shale oil remains a puzzle. Like Canada’s Oil Sands, kerogen from oil shale could be either dug up or extracted in place as in “in situ” processes. Cheap hydrogen and low cost cleaning also need solutions. Petroleum isn’t in short supply, easy to extract, refine and clean petroleum is, though.
So when the Chinese paper appeared in the American Chemical Society journal Energy & Fuels a certain acclaim is due. From the abstract:
Because of high contents of nitrogen, sulfur, and unsaturated hydrocarbons in shale oil, its potential use as a substitute fuel is limited. In this paper, catalytic hydrotreating of the diesel fraction (200?360 °C) from Fushun shale oil was preliminarily investigated in a fixed-bed reactor. Hydrotreating experiments were carried out using various available commercial catalysts, including CoMo/Al2O3, NiW/Al2O3, and NiMoW/Al2O3, at different conditions of temperature, hydrogen pressure, liquid hourly space velocity (LHSV), and ratio of hydrogen/feedstock. The results showed that the NiMoW catalyst was most active for heteroatom removal, in comparison to other catalysts. Under relative mild conditions, it was possible to produce clean diesel from a Fushun shale oil distillate. The produced oil had low contents of sulfur, nitrogen, and alkene, reduced density, and increased cetane number, and it could be used as a more valuable fuel.
There’s a piece of the puzzle on the cleaning side. Just how clean or clean enough isn’t yet clear. China doesn’t give much care to CO² or other environmental matters. But the knowhow is now out on the catalyst discovery.
Numbers passed around have U.S. shale oil worthwhile at perhaps as low as $35 a barrel, a number that challenges the imagination. Canada’s Oil Sands gets into financial trouble as oil prices get close to $50 so its a sure bet that the kerogen to bitumen step is going push it higher. But the reserves in shale are getting closer to market. Big breaks in technology will only help.
But the hard price of crude oil isn’t there yet. Today’s mid $70’s is a function of OPEC limiting the market. Just what a barrel of oil is worth is something less than that. The conditions for billions of investment aren’t ripe yet.
The technology is closer. But the politics further. There is considerable doubt that the world’s largest reserve will ever get to market as politics stand in the way. The leftist politicians are betting technology and public opinion will get petroleum out of the energy market. Keep in mind, they bet with your life – if they lose you lose.
From the most hydrogen rich petroleum, natural gas, to lesser hydrogen rich crude oil, heavy crude oil, bitumen, kerogen all the way to hard anthracite coal there are stunning amounts of carbon-based fuels around. The biosphere is busily recycling carbon through plants attaching hydrogen back and releasing oxygen for us to breath.
The question for the thoughtful is, can the human species control itself such that the carbon cycle can keep up? The answer is an obvious, yes, with energy inputs from solar, geothermal and nuclear fission and fusion – a happy carbon cycle is possible supporting a large human population and the plants and animals of the world.
Oil shale could have a role, soon if the technology develops at a good pace and politics pays attention to its responsibilities instead of its idealisms.
By. Brian Westenhaus of NewEnergyandFuel.com
Source: Getting to all that shale oil