Different thermal technologies, such as "gasification", "pyrolysis", "incineration", "bio gas" etc are available. The composition of municipal is not uniform every where. Similarly, there is change in solid waste generation rate (quantity) also. Therefor, when there is change in composition and quantity, the energy contents will also change. Therefore, there is a need to identify suitable technology for sustainable solid waste management and make the energy recovery economical.
So what type technology is suitable for what composition with what generation rate?
In my opinion, the uncontrolled disposal of municipal solid waste combined with inadequate collection, recycling or treatment is already leading to ill effects to health & environment. If we think of SWM by thermal technology, then there will be an added cost plus a possible escalation of ill effects without necessarily being capable of recovering energy at a more proper edge.
I think that anaerobic digestion (biomethanation) of organic solid waste is the most promising treatment option. This is not a cost-intensive process & the produced CH4 is one of the best fuels with relation to heat value and reduced negative effect on the broad environmental impacts.
I think that by far the most suitable and feasible technology for municipal organic waste management is anaerobic digestion with biogas production. I would indicate as a top example the technology implemented by BSR company in Berlin that I had the opportunity to visit. The process is dry anaerobic digestion, the feedstock has ca. 60% total solids. I attach a presentation film and some information on the annual performance of the facility just to let you have an idea about this. It should be noted that the BSR company has switched from incineration to dry fermentation, obviously due to both economical and environmental benefits.
https://youtu.be/R9EbWOl18e8
Dear Professor Nafees Mohammad,
As rightly pointed out, the heterogeneous nature of MSW does not lend itself to one technology. Typically, the most appropriate technology for valorization of MSW will depend on a number of factors including but not limited to the physicochemical properties, set up cost, end product, evolved gas emissions among others.
For high moisture organic based MSW, technologies that eliminate the need for the energy intensive process of drying will suffice. Example include; liquefaction, hydrothermal carbonization (HTC) or wet torrefaction. However, the cost of pressurized equipment and disposition towards HHV solid products from these processes remains a draw back.
Conversely, low moisture, homogeneous MSW streams can be valorized via gasification or combustion to yield fuel (or syngas) and flue gases, respectively. Existing coal gasifiers or biolers can be modified or retrofiited to valorise MSW. However, problems of ash formation, agglomeration, particulate matter are potential drawbacks of these technologies.
In conclusion, the selection of an appropriate technologies for MSW valorization must be preceded by physicochemical characterization of MSW and an indepth techno-economic and life cycle analyses of the process and its impact on the environment.
Hope this helps.
Best regards,
BBN
I would add that my previus answer was refered to the organic fraction of municipal waste, assuming that muncipal waste is sorted at source and all the other recyclable fractions were separated. Biogas technology is not a thermal technology but biochemical and it is most adequate for wet biowaste (humidity > 50%), it excludes the much energy-consuming drying and allows a more favorable energy balance of the process. Certainly the biowaste composition varies but an average composition may be considered on large geographycal areas.
I got very good response and am very thankful to all contributors (Nizar Matar, Bemgba Bevan Nyakuma, and Mateescu).
To be more specific, I would like to have a study on thermal plant purely based on solid waste with following information.
Solid waste Generation rate (per day).
Composition of solid waste.
Population of that area
Electricity or any other out put produced.
And the most important, running expenditure (total cost per month).
Dear Prof.,
There are quite a number of studies on this in literature.
Specifically the group of Assoc Prof Haslenda Hashim >> http://bit.ly/2GauslR at my university is working in this area.
Best of luck,
BBN
Hi Nafees,
Pyrolysis is a great method to dispose solid organic waster. You can also produce crude oil and then after improving this crude oil, it can be used as diesel-biodiesel blends in CI engines.
Article Improvement of Waste Tire Pyrolysis Oil and Performance Test...
Dear Nafees Mohammad,
The selection of WTE technologies depend on the waste origin, capital and operational cost, technological efficiency and complexity coupled with labor skill requirements and geographical locations of the plants. In addition, merits and demerits, technical and economical differences of each WTE technology is also considered in their selection.
Please see the following publications of my research group in this regard.
Article Waste Biorefineries: Enabling Circular Economies in Developi...
Article Waste to energy potential: A case study of Saudi Arabia
Article Developing waste biorefinery in Makkah: A way forward to con...
Article Waste-to-energy potential in the Western Province of Saudi Arabia
I hope you will find them interesting and relevant.
With regards,
Nizami
Kindly, check two of the quantification and characterization exercises on the waste to energy technologies from the organic solid waste:
https://doi.org /10.1016/j.rser.2017.09.051 “Waste to Energy Bio-digester Selection and Design Model for the Organic Fraction of Municipal Solid Waste”.
https://doi.org/10.1016/j.rser.2018.04.070 "Quantification Characterization of Different Carbonaceous Biomass for Waste to Energy Recovery in South Africa,"
I think pyrolysis is a suitable method to handle this kind of waste. It has several advantages over other thermochemical conversion processes. It requires small size equipment volume, investment scale cost is meager, and takes less space than other thermochemical conversion processes.
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