Municipal solid waste incineration
Download
1 / 33

Municipal Solid Waste Incineration - PowerPoint PPT Presentation


  • 412 Views
  • Updated On :

Municipal Solid Waste Incineration. Combustion Types. Incineration (energy recovery through complete oxidation) Mass Burn Refuse Derived Fuel Pyrolysis Gasification Plasma arc (advanced thermal conversion). Gasification.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Municipal Solid Waste Incineration' - daniel_millan


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Combustion types l.jpg
Combustion Types

  • Incineration (energy recovery through complete oxidation)

    • Mass Burn

    • Refuse Derived Fuel

  • Pyrolysis

  • Gasification

  • Plasma arc (advanced thermal conversion)


Gasification l.jpg
Gasification

  • Partial oxidation process using air, pure oxygen, oxygen enriched air, or steam

  • Carbon converted into syngas

  • More flexible than incineration

  • More public acceptance



Pyrolysis l.jpg
Pyrolysis

  • Thermal degradation of carbonaceous materials

  • Lower temperature than gasification

  • Absence or limited oxygen

  • Products are gas, liquid, solid char

  • Distribution of products depends on temperature


Waste incineration advantages l.jpg
Waste Incineration - Advantages

  • Volume and weight reduced (approx. 90% vol. and 75% wt reduction)

  • Waste reduction is immediate, no long term residency required

  • Destruction in seconds where LF requires 100s of years

  • Incineration can be done at generation site

  • Air discharges can be controlled

  • Ash residue is usually non-putrescible, sterile, inert

  • Small disposal area required

  • Cost can be offset by heat recovery/ sale of energy


Environmental considerations l.jpg
Environmental Considerations

  • Tonne of waste creates 3.5 MW of energy (eq. to 300 kg of fuel oil) powers 70 homes

  • Biogenic portion of waste is considered CO2 neutral (tree uses more CO2 during its lifecycle than released during combustion)

  • Should not displace recycling


Waste incineration disadvantages l.jpg
Waste Incineration - Disadvantages

  • High capital cost

  • Skilled operators are required (particularly for boiler operations)

  • Some materials are noncombustible

  • Some material require supplemental fuel

  • Public disapproval

    • Risk imposed rather than voluntary

    • Incineration will decrease property value (perceived not necessarily true)

    • Distrust of government/industry ability to regulate


Three ts l.jpg
Three Ts

  • Time

  • Temperature

  • Turbulence


System components l.jpg
System Components

  • Refuse receipt/storage

  • Refuse feeding

  • Grate system

  • Air supply

  • Furnace

  • Boiler


Energy mass balance l.jpg
Energy/Mass Balance

Energy Loss (Radiation)

Flue Gas

Waste

Mass Loss (unburned

C in Ash)


Flue gas pollutants l.jpg
Flue Gas Pollutants

  • Particulates

  • Acid Gases

  • NOx

  • CO

  • Organic Hazardous Air Pollutants

  • Metal Hazardous Air Pollutants


Particulates l.jpg
Particulates

  • Solid

  • Condensable

  • Causes

    • Too low of a comb T (incomplete comb)

    • Insufficient oxygen or overabundant EA (too high T)

    • Insufficient mixing or residence time

    • Too much turbulence, entrainment of particulates

  • Control

    • Cyclones - not effective for removal of small particulates

    • Electrostatic precipitator 

    • Fabric Filters (baghouses) 


Metals l.jpg
Metals

  • Removed with particulates

  • Mercury remains volatilized

  • Tough to remove from flue gas

  • Remove source or use activated carbon (along with dioxins)


Acid gases l.jpg
Acid Gases

  • From Cl, S, N, Fl in refuse (in plastics, textiles, rubber, yd waste, paper)

  • Uncontrolled incineration - 18-20% HCl with pH 2

  • Acid gas scrubber (SO2, HCl, HFl) usually ahead of ESP or baghouse

    • Wet scrubber

    • Spray dryer

    • Dry scrubber injectors


Nitrogen removal l.jpg
Nitrogen removal

  • Source removal to avoid fuel NOx production

  • T < 1500 F to avoid thermal NOx

  • Denox sytems - selective catalytic reaction via injection of ammonia


Air pollution control l.jpg
Air Pollution Control

  • Remove certain waste components

  • Good Combustion Practices

  • Emission Control Devices


Devices l.jpg
Devices

  • Electrostatic Precipitator

  • Baghouses

  • Acid Gas Scrubbers

    • Wet scrubber

    • Dry scrubber

    • Chemicals added in slurry to neutralize acids

  • Activated Carbon

  • Selective Non-catalytic Reduction


Role of excess air control three ts l.jpg

Stoichiometric

Insufficient O2

Excess Air

Role of Excess Air – Control Three Ts

T

Amount of Air Added


Role of excess air cont d l.jpg

Stoichiometric

Insufficient O2

Excess Air

Role of Excess Air – Cont’d

Increasing Moisture

Amount of Air Added


Role of excess air cont d22 l.jpg
Role of Excess Air – Cont’d

Stoichiometric

NOx

T

Optimum T

Range

(1500 – 1800 oF)

PICs/Particulates

Insufficient O2

Excess Air

Amount of Air Added


Slide23 l.jpg
Ash

  • Bottom Ash – recovered from combustion chamber

  • Heat Recovery Ash – collected in the heat recovery system (boiler, economizer, superheater)

  • Fly Ash – Particulate matter removed prior to sorbents

  • Air Pollution Control Residues – usually combined with fly ash

  • Combined Ash – most US facilities

    combine all ashes



Ash reuse options l.jpg
Ash Reuse Options

  • Construction fill

  • Road construction

  • Landfill daily cover

  • Cement block production

  • Treatment of acid mine drainage


Slide26 l.jpg

Refuse Boiler

Fabric Filter

Stack

Spray Dryer

Tipping

Floor

Ash Conveyer

Metal Recovery

Mass Burn Facility – Pinellas County





Return to home page l.jpg
Return to Home page

Updated August 2005


ad