Pelletization of Municipal Solid Wastes

MSW is a poor-quality fuel and its pre-processing is necessary to prepare fuel pellets to improve its consistency, storage and handling characteristics, combustion behaviour and calorific value. Technological improvements are taking place in the realms of advanced source separation, resource recovery and production/utilisation of recovered fuel in both existing and new plants for this purpose. There has been an increase in global interest in the preparation of RDF containing a blend of pre-processed MSW with coal suitable for combustion in pulverised coal and fluidised bed boilers.

Pelletization of municipal solid waste involves the processes of segregating, crushing, mixing high and low heat value organic waste material and solidifying it to produce fuel pellets or briquettes, also referred to as Refuse Derived Fuel (RDF). The process is essentially a method that condenses the waste or changes its physical form and enriches its organic content through removal of inorganic materials and moisture. The calorific value of RDF pellets can be around 4000 kcal/ kg depending upon the percentage of organic matter in the waste, additives and binder materials used in the process.

The calorific value of raw MSW is around 1000 kcal/kg while that of fuel pellets is 4000 kcal/kg. On an average, about 15–20 tons of fuel pellets can be produced after treatment of 100 tons of raw garbage. Since pelletization enriches the organic content of the waste through removal of inorganic materials and moisture, it can be very effective method for preparing an enriched fuel feed for other thermochemical processes like pyrolysis/ gasification, apart from incineration. Pellets can be used for heating plant boilers and for the generation of electricity. They can also act as a good substitute for coal and wood for domestic and industrial purposes. The important applications of RDF are found in the following spheres:

  • Cement kilns
  • RDF power plants
  • Coal-fired power plants
  • Industrial steam/heat boilers
  • Pellet stoves

The conversion of solid waste into briquettes provides an alternative means for environmentally safe disposal of garbage which is currently disposed off in non-sanitary landfills. In addition, the pelletization technology provides yet another source of renewable energy, similar to that of biomass, wind, solar and geothermal energy. The emission characteristics of RDF are superior compared to that of coal with fewer emissions of pollutants like NOx, SOx, CO and CO2.

RDF production line consists of several unit operations in series in order to separate unwanted components and condition the combustible matter to obtain the required characteristics. The main unit operations are screening, shredding, size reduction, classification, separation either metal, glass or wet organic materials, drying and densification. These unit operations can be arranged in different sequences depending on raw MSW composition and the required RDF quality.

Various qualities of fuel pellets can be produced, depending on the needs of the user or market. A high quality of RDF would possess a higher value for the heating value, and lower values for moisture and ash contents. The quality of RDF is sufficient to warrant its consideration as a preferred type of fuel when solid waste is being considered for co-firing with coal or for firing alone in a boiler designed originally for firing coal.

About Salman Zafar

Salman Zafar is a renowned expert in waste management, biomass energy, waste-to-energy and sustainable development. He is proactively engaged in creating mass awareness on renewable energy, waste management and environment. Salman is the CEO of BioEnergy Consult, apart from being the Founder of Cleantech Solutions and EcoMENA. Salman has successfully accomplished a wide range of projects in the areas of biogas technology, biomass energy, waste-to-energy and solid waste management. He has participated in numerous national and international conferences and has authored many articles in reputed journals and magazines. Salman can be reached at salman@bioenergyconsult.com or salman@cleantechloops.com.
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6 Responses to Pelletization of Municipal Solid Wastes

  1. Goodday Sir, pls hope this correspondence meets you well. How can we workout a partnership that can ensure this technology can be sold by us exclusive to various nations across Africa where we have strong contacts in government. I await your reply ernestly so that we can commence a fruitful relationship. Thank You.

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  3. Christan Grangé says:

    Dear Sir
    Thanks for this article.
    Would like to know who you would recommend as pellet machine suplier having one or several references on pelletizing / briquetting RDF.
    Best regards
    Christian Grangé

  4. Ravi keshri says:

    Dear sir,
    i want to open a small source of pelletizing/briquetting RDF in my town in india .so i need your help in installing a plant , please help me regarding this

  5. NAGARJUNA says:

    Dear sir,
    i want to open a possible micro /small scale pelletizing/briquetting RDF in my town in india with minimum capital .I need your help in installing a plant , please help me regarding this
    Reply

    NAGARJUNA REDDY

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