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2xMore Challenge

Depollute water with wood chips

  • Creator
  • #3614

    Mathieu VERDET

    According to the World Business Council for Sustainable Development (WBCSD), water is the first material used in the world.  This liquid gold is an essential resource for the ecosystem, the biodiversity which humans and more generally the earth. Unfortunately, in many part of the world polluted water is a sad reality. That’s why it’s already the challenge of yesterday.

    The concept:

    One of most used method to clean up water is activated carbon.  “It is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions.”

    Usually, activated carbon is derived from charcoal and increasingly  biochar based on biomass, wood and crushed wood which are more benefic for environment.  Nevertheless, pyrolysis is an energy-guzzling process. Consequently, the choice of the source of energy is a major stake.

    So the concept is to use our wood chips to transform them in activated carbon via pyrolysis feed by renewable energy.

    One choice of renewable energy:

    Solar energy is a new approach proposed in recent studies to assist fast pyrolysis. Combined or not with other sources, the main goal is to limit the pollution by a reduction of emissions as presented in the link. Beyond the pyrolysis and charcoal, every part of the “reaction” can be optimized and used. The third photo resumes an example of process.

Environmental asset and example:

    Water is everywhere and in connections with each part of our environment. So how can evaluate or illustrate all the range of possibilities? Nonetheless, for example today it is used for drinking water, waste water. There are also experimentations to clean water in contact with nuclear materials.


    In spite of a strong consumption of energy, with a good process, low emissions can be obtained. If this process is not necessary the most economic, there are no doubt that it is a big improvement for the environment and the ecosystem.

Viewing 9 replies - 1 through 9 (of 9 total)
  • Author
  • #3620


    Image result for pyrolysis

    Since, Pyrolysis is a thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen (or any halogen).
    It requires a lot of energy to convert wood chips/saw dust into activated carbon using sophisticated equipments which makes the process expensive. On the other hand it is
    cheaper to get natural activated carbon which is cheap and abundant. So it might not serve the purpose, still I think it is a good possible application when we run out of activated carbon.

    Mathieu VERDET

    Pyrolysis require lot of energy, it’s true. But for a good outcome, should we be limited by a simple data of consumption? It’s not my point of view. I think that in engineering we mustn’t be a victim but a creator of solution!!

    For me, a good solution is to consider or implement a renewable energy in the process in order to have a low emission impact. There are lot’s of systems today.

    In other part, equipment is maybe sophisticated, but what is the problem? One of goals of this challenge is to have the best value for the environment, not a cheap process. In addition, new production lines are not necessary required. It can also to be a product of substitution.

    Concerning the materials, you claim that “On the other hand it is cheaper to get natural activated carbon which is cheap and abundant”. Do you have sources?  Because I don’t find documents in this way. If it is the same assertion that “concrete have a less environmental impact than wood”, permit me to doubt. If it is so cheap and abundant, my personally observation is : why it is not more used and why some water or air are still polluted?

    For example, not later than this year Montreal pours out 8 000 000L of waste water in the river. Do you think Its normal?

    To finish, my first idea was to propose a substitute  clean wood/biomass which can be used in other process where it must be clean with higher value. Here, contamination is not a problem.



    Will u be able to produce 1 KG of activated carbon by using this process for less than the cost of naturally occurring 1 KG of activated carbon?

    Even if someone produces it by this process to save environment then definitely they will be loosing money. For your information this is an existing patented innovation.

    Also  Activated carbon is good but it does have its limitations, it cannot purify all kinds of polluted water. That is the reason u still see polluted water, there is no wonder material to purify water.

    I found it to be cheap online.





    Mathieu VERDET

    In a first time, thanks for the linked patented. It is for sawdust but it prove that is possible. I think that we can make the same or a simililar process. Unfortunately I don’t work in chimistry so I can’t specify the best process for the concept.

    For your second remark, I not understand what you understand by  ” naturally occuring activated carbon”. Have you an example? For me the raw materials are mainlly organic materials.

    In all case, I think we can’t speak about the cost because we can’t consider this specific application alone. There are lot’s of extern parameters and connections. Moreover, I think it’s not the priority today. Money are not the center of the world for many projet!!!

    To finish, we can’t depollute all water but much more than today. If it is really cheap, for me it’s even sadder.





    Damien MATHIS

    I agree with you Mathieu.

    There is no need to excavate more Carbon than we actually do. Activated carbon created from these wood plates is short-cycle carbon.


    Mathieu VERDET

    Thank you for your support @Damien



    I think if u use a renewable energy source for the pyrolysis as mentioned earlier by u, u can add value to the concept. For example solar energy, if there is something like a reactor and concentrated solar energy is used to heat it up to bring about pyrolysis then it will be beneficial to environment as the end product can be used for purification or whatever process. Trucks of saw dust/ wood chips can dump their wood waste into it and the same trucks can carry back activated carbon already produced from the reactor.Following information might be of use to u.

    I am just giving my opinion and suggestions from my view point u r free to accept/reject/criticize.I would appreciate if u understand. Thanks.



    Mathieu VERDET

    Thank you for your return and for the link. It is a very good suggestion and as you recomand, I will add directly in the concept for improvement.

    If we not agree in all subjets, I found the debates very interesting and I think that finally we find and improve the solutions. Sorry if one or two responses were not very kind ;).




Viewing 9 replies - 1 through 9 (of 9 total)

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