Small-scale Incineration of Waste for Energy Recovery

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Does anyone ​have experience ​with small-​scale ​incineration of ​waste streams ​including ​sewage sludge ​in small units ​i.e capacity as ​low as 1.5 ​tonnes/day, ​with provision ​for energy ​recovery?  ​

Is it ​profitable? ​What amount of ​energy do you ​gain? ​

Specifically, ​how much energy ​can be ​recovered from ​a tonn of ​sewage sludge?​

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11 Answers

  1. It possible!
    Please, be ​contact  ​for more ​information via ​email: nikita.​chikin@​kaukointernational​.​com   ​    ​

    You will get ​answer for your ​questions from ​Finland! ​

  4. For incinerating small amounts (~1.5 tonnes daily), consider a scaled up rocket stove. These have one advantage that they'll burn bio-mass, without giving smoke. Further, such incinerators could be built locally, using available clay materials. Examples can be seen at:  http://tzenvirohealth.wixsite.com/ceramics

    Consider additionally, searching for answers among those concerned about disposal of medical waste. They have a particular problem with that portion of their waste that's hazardous, but I'm supposing that for the applications of which you speak, this is not the situation.

  5. Usually you need to calculate the whole cost of project (CAPEX & OPEX) plus you need to think about gas emmison regulation.  Most of companies in Europe forced to burn sludge because their farm land already saturated with P&N and there is no demand on fertiliser sludge. And some companies want show that they are green companies.

    As well you need to dewater the sludge to allow it to burn and this process is costly. If you add all OPEX , H&S risks and hassles including government consents and approval. Convert sludge to electricity is a very expensive option.

    Regards

    Majed Murad

     

  6. Dear Miria,

    1500 kg per day of slaudge such as com out of belt press still 80% of moisture this mean you have 300 kg of organic matter to use to produce energy. (12.4 kg per hour).

    It is too small quantity to have a return of investment.

    You can also to add other organic waste or matter to increase total weight.

    At least you have to reach 50 kg/h of dried organic matter to have thermal energy

    and you have to reach 100 kg/h d.o.m to have electrical energy.

    By your small quantity a profitable solution is to convert sludge into fertilizer or soil improver. Our company produce small waste to energy plant or sludg to fertilizer solution in case you are interested to develope a project.

    Cheers

  7. there are other ways to treat sludge and recover nutrients that have far smaller energy footprint.  

    for such a small quantity, you need a smaller modular unit that is cheap and cost very little to operate.  this 1.5 tones of sludge you have, what is the percentage of moisture?

    cheers

     

  8. Hi Miria - instead of burning sludge in small quantities, why not consider the mobile (truck-mounted) South African system called LaDePa developed by Particle Separation Systems Technologies and trialled in Durban? LaDePa produces a safe, pelletised sludge product that is safe to apply to food crops.  If you search for LaDEPa on the web you will find technical papers on it, and a You Tube video. 

  9. Hello Miria,

    with small scale, it will be beneficial to have energy recovery from sewage sludge.  A

    You may want to think on Anaerobic Digestion (AD) for small scale. AD will produce methane gas that can be used for energy recovery. There are examples of portable units for organic waste.

    here is an example of technology developed int he UK that use AD on a small scale unit for food waste

    http://seabenergy.com/products/anaerobic-digesters/  

     

    Regarding how much energy can be recovered from a tonne of sewage sludge, that will depend on many factors including the process, water content and technology used.  Most of the Water companies int he UK use AD and CHP units for treating the sewage sludge and energy recovery. for example, In a typical AD process, each tonne of dry matter fed will produce 350m3 of biogas (65% methane) which generates up to 820kWh of electrical energy. In a typical Advanced AD-Thermal Hydrolysis Plant (AHP)process, each tonne of dry matter fed will produce 450m3 of biogas which would generate up to 1,100kWh of electrical energy. However, THP demands an input high-grade heat and additional electrical energy, when compared with conventional AD.

     

    Have a look at the attached file, which will give you an overview of the current practice of AD in the UK.

     

  10. Dear Miria,

    The process is the same for large scale or small scale, if you have small then power generation KW rather than MW.

    Incineration technology is the controlled combustion of waste with the recovery of heat to produce steam that in turn produces power through steam turbines .Sewage sludge incineration – in some locations sewage sludge are incinerated separately from other wastes in dedicated installations, in others such waste is combined with other wastes (e.g. municipal wastes) for its incineration. Two suitable methods to directly convert sewage sludge into useful energy on-site at the waste water treatment plant. Both processes consist mainly of four devices: de watering and drying of the sewage sludge, gasification by means of fluidised bed technology (followed by a gas cleaning step) and production of useful energy via CHP units as the final step.

     

    Energy output/Input ratio=

    ∑(HHV of the Product X(mass of the product)

                                 Energy Input

     

    The approximate energy efficiency of each process can be estimated by the equation above, while depending on different requirements and characteristics of each process, the energy input calculation may differ method to method and may be difficult to determine due to shortage of experimental data reported.

    During the process of incineration, the waste material that is treated is converted in to gases, particles and heat. These products are later used for generation of electricity. The gases, flue gases are first treated for eradication of pollutants before going in to atmosphere. Waste-paper solid waste has to go somewhere and one of the easiest ways of dealing with the stuff is to incinerate it. But turning sludge to ash means adding an additional energy cost to the long chain of waste management needs.

     

  11. yes, it is possible to do it  ! but the quantity being very small...the cost of recovery will be high !