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Oil shale (part II)

September 5, 2008

In the previous post on oil shale, something about the geology and nature of oil share in Jordan was given. In this post, more on the options of how to utilize this material will be presented. Essentially, these options are either direct combustion for electrical generation or retorting to extract the oil from the rock.

From a technical point of view, the simplest approach is to burn the shale to produce heat, and then electricity. A number of experiments have been made on this, and have been discussed in the Bseiso report I referred to in the first post. All of the tests indicated economic feasibility of direct burning. Essentially, the idea is to crush the oil shale to sand-sized fragments and to ignite the kerogen in the rock. One concern about this is the high level of sulfur in the oil shale, potentially causing air pollution problems. Fortunately, the limestone in which the kerogen is present decomposes in heat to lime, which can react with the sulfur dioxide produced by burning the shale to produce calcium sulfate. The sulfur issue needs to be considered during any designing of a shale burning plant.

Another issue is what to do with all of the residue (fly ash) that will result from burning oil shale. Depending on the scale of use, large volumes of lime-rich ash have the potential of polluting aquifers (by reaching extremely high pH values, possibly leaching heavy metals into the ground water) as well as being sources of dust that may impact air quality and ecosystem stability in the areas where it is kept.

Some studies have suggested that the fly ash would be suitable raw material for cement production. Preliminary tests have suggested that cement produced with this material does not shrink in a predictable pattern, which may be a problem. However, other properties such as strength and thermal conductivity show more promising results. Further experimentation may lead to a better product.

Other potential uses that have been investigated include the use of the ash is soil stabilization, the production of zeolites for water treatment (we have natural zeolites that can be used in a similar way) and improving asphalt mixtures (which is something to be welcomed).

In conclusion, the use of oil shale for direct combustion is economically feasible, although it may no be the optimal way to use the resource. Comparative studies of oil extraction versus direct combustion show that the former is a more lucrative option (see the table on page 37 here. The numbers are outdated but the variations are still similar). Environmental problems of direct burning include the large amount of waste produced (fly ash) and the potential problem of sulfur, which can be managed provided there is good engineering and monitoring.

I will discuss retorting in a future post (In Sha’ Allah).

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6 comments

  1. Salam,
    thanks for the article. from your description, it seems that there are no existing plants for oil-shale direct combustion active in the world today, right? I say that because if there were, then the problems you describe would have more concrete solutions. is this right?

    are there any plants in the world today that apply the other method (oil extraction)?

    thanks,
    Muhammad


  2. Hello,

    Actually, there are commercial facilities, that both burn oil shale and extract oil from the shale. Such facilities exist in Estonia, Brazil, and China, among others.

    The economics of extraction and utilization in these countries is different from Jordan, because in Jordan it has always been viewed from a strictly financial angle. The idea of energy independence was never an issue because Iraq, Saudi Arabia and the other oil rich states gave us oil for free or at deep discounts. There never was incentive to build the infrastructure or practical know-how to do this. Things have changed now, but any decision will still only be judged from a financial stand point.

    Electrical generation is now dependent on discount natural gas imported from Egypt. This deeply cuts the feasibility of electrical generation from oil shale. Moreover, the environmental issues related to strip mining, sulfur, water use and groundwater contamination are avoided. Perhaps this will change if we stop getting cheap Egyptian natural gas, and if the nuclear energy plans flounder.

    As for retorting, I hope to write a new post about it soon.


  3. […] science and engineering Lighting a candle « Oil shale (part II) Oil shale (part III) September 7, 2008 Part I (geology and […]


  4. Salam,
    thanks for linking to my blog – I know I don’t write enough to deserve it.

    So, now to my question. These countries that implemented the burning technique, how do they solve these problems:

    1- why do they do with the residue (fly ash)?
    2- how do they maintain air quality?

    finally, I found your article in arabic (from 2005) for Nuclear power in jordan. which of the two projects would recommend? they both are concerned with providing energy.


  5. On a different note: I’ve always thought on what it means to be a scientist in Jordan, and mashallah you’ve done it. I was previously under the assumption that our universities do research in topics unrelated to Jordan. However, looking at your papers, and the many you cite, this is simply not true. And even further, most of the people on scholarships here in the US have done very interesting and seemingly useful masters theses in Jordan.

    the question is, what happens to this research? is any of the scientists in jordan successful in turning his/her research into projects? or regulations? any examples you might have in mind.

    I know that academics usually do not mix with politicians (with few exceptions like badran), but since most of our policies come from the royal court, I think some kind of personal or informal bridges must be built between universities and royal court.

    what do you think about this issue? how do you evaluate our current situation in jordan? and what do you think the way out of it?

    for example, is your research on shallow underground water in the desert getting attention from the government?


  6. Hi,

    I think that some of the fly ash is used to produce cement. Probably most is piled in waste heaps. Fly ash from coal is also a problem in a lot of cases.

    As for air pollution, it depends on the nature of the pollutants. Jordanian shale oil is richer in sulfur than in other places. In the US, the problem of sulfur rich coal was “solved” by depending on low sulfur coals in the Appalachians instead of the Rock Mountains. Dust particles can be removed if good filter systems are installed.

    The choice of nuclear energy technology is beyond my scope of expertise. It is mostly an economic decision, although political, environmental, proliforation and safety issues will also come into play (you can see more on my nuclear energy post https://jordanscience.wordpress.com/2008/08/20/nuclear-jordan/).

    I have a post where I discuss the issue of policy and
    science (https://jordanscience.wordpress.com/2008/09/01/science-and-policy/). Clearly, there is a disconnect between science and policy that needs to be addressed. Possibly there should be an institutional mechanism whereby exchange of ideas and information takes a more structured course.

    In fact, one of the reasons why I started this blog is to raise awareness about what is going on in the scientific community in Jordan. I am happy that you are asking these questions, because this is the type of response I was hoping for.

    You can email me if you like. I will be happy to hear from you.



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