Incineration of waste offers the following advantages:

  1. Volume reduction: Important for bulky solids or wastes with a high combustible and/or moisture content.
  2. Detoxification: Especially for biological waste, pathologically contaminated materials, toxic organic compounds, and combustible carcinogens.
  3. Environmental impact mitigation: Especially for organic materials that leach from landfills or create odour nuisances. Secondly, the impact of the CO2 “greenhouse gas” generated in incinerating solid waste is substantially less than that of the methane (CH4) and CO2 generated in landfill operations. An analysis of the time-dependent atmospheric response to greenhouse gas emissions from landfills in comparison to resource recovery facilities by the Harvard School of Public Health in Boston, Massachusetts shows that the atmospheric warming impact from landfilling is from 45 to 115 times that of combustion alternatives. Also, because of strict air pollution emission requirements applicable to municipal refuse incinerators, the criteria pollutant air emission per kilowatt of power produced is significantly less than that generated by the coal and oil-burning utility plants whose electricity is replaced by “waste-to-energy” facilities.
  4. Regulatory compliance: Applicable to fumes containing odorous or photoreactive organic compounds, carbon monoxide, volatile organic compounds (VOCs), or other combustible materials subject to regulatory emission limitations.
  5. Energy recovery: Important when large quantities of waste are available and reliable markets for by-product fuel, steam, or electricity are nearby.
  6. Stabilization in landfills: Biodegradation of organic material in a landfill leads to subsidence and gas formation that disrupts cell capping structures. Destruction of waste organic matter eliminates this problem. Incineration also forms oxides or glassy, sintered residues that are insoluble (non-leaching).
  7. Dilution: Particularly important for low-level radioactive wastes where the combustion of organic solvent carriers with an excess of combustion air and fuel dilutes the concentration of the residual (and non-destructible) radioactive isotopes below levels representing health and safety risks.
  8. Sanitation: Destruction of pathogenic organisms presenting a hazard to public health.
  9. Secondary environmental impacts: Air, water, and ash residue pollution are often regarded as strong negatives for thermal processing. Certainly, these issues can be problems but, as a matter of perspective, it is worth noting that when faced with these “problems” as a challenge, the owners, operators, and developers/vendors of thermal processing systems have routinely met or bested regulatory requirements. This consistent success makes these impacts “advantages” as well as “disadvantages.”
Operating counter to these advantages are the following disadvantages of incineration:
  1. Cost: Usually, incineration is a costly waste processing step, both in initial investment and in operation.
  2. Operating problems: Variability in waste composition and severity of the incinerator environment result in many practical waste-handling problems, high maintenance requirements, and equipment unreliability.
  3. Staffing problems: The low status often accorded to waste disposal can make it difficult to obtain and retain qualified supervisory and operating staff. Because of the aggressive and unforgiving nature of the incineration process, staffing weaknesses can lead to adverse impacts on system availability and maintenance expenses.
Secondary environmental impacts:
  1. Air emissions: Many waste combustion systems result in the formation of odours, sulphur dioxide, hydrogen chloride, carbon monoxide, carcinogenic polynuclear hydrocarbons, nitrogen oxides, fly ash, particulate fumes, and other toxic or noxious materials in flue gases. The control of emissions to very low levels is within the capability of modern air pollution control technology.
  2. Waterborne emissions: Water used in wet scrubber-type air pollution control often becomes highly acidic. Scrubber blowdown and wastewater from residue quenching may contain high levels of dissolved solids, abrasive suspended solids, biological and chemical oxygen demand, heavy metals, and pathogenic organisms. As for the air pollutants, control of these pollutants can be readily affected to discharge standards using available technology.
  3. Residue impacts: Residue disposal (fly ash and bottom ash) presents a variety of aesthetic, water pollution, and worker health-related problems that require attention in system design and operation.
  4. Public sector reaction: Few incinerators are installed without arousing concern, scrutiny, and, at times, hostility or profound policy conflicts from the public, environmental action groups, and local, state, and federal regulatory agencies.
  5. Technical risk: Process analysis of combustors is very difficult. Changes in waste character are common due to seasonal variations in municipal waste or product changes in industrial waste. These and other factors contribute to the risk that a new incinerator may not work as envisioned or, in extreme cases, at all. In most cases, the shortfall in performance is realized as higher than expected maintenance expense, reduced system availability, and/or diminished capacity. Generally, changes in waste character invalidate performance guarantees given by equipment vendors.