Integrated green technologies for MSW

Prof. Dr. Mamdouh F. Abdel-Sabour

International Innovative Environmental Solution Center (IIESC) Prof. Emeritus of soil science, Department of Soil and Water Research,

Nuclear Research Center, Atomic Energy Authority.

http://sa.linkedin.com/pub/mamdouh-sabour/2a/999/444/

https://www.researchgate.net/profile/Mamdouh_Abdel-Sabour

wise2007egy@yahoo.com

Content I: Automated waste collection system Introduction Component of generated MSW MSW collection Automated waste collection system Capability of one collection system Basic concept System summary Waste inlets Waste collection terminal Landscape plan for waste collection terminal Considering an investment cost Product summary

Content II: MSW thermo-chemical conversion technologies Recycling Progress of technology for waste destruction (for non-recyclable MSW) Combustion types Benefit of WTE Incineration Carbon and energy considerations System components WET incinerator with pollution controls Pollution controls Air pollution control Bottom Ash treatment

Pyrolysis Example: Ethanol plant

Gasification Conclusions

Introduction

Most the generated MSW are disposed in landfill which is kind of wasting a recyclables resources and losses of its energy content, in addition of the adverse impact of this practices on the environment as a result of ground water pollution and gaseous emissions which cause the global warming problem.

Possible Waste Management Options : Waste Minimization Material Recycling Waste Processing (Resource Recovery) Waste Transformation Sanitary Land filling.

Processing / Treatment should be : Technically sound Financially viable Eco-friendly / Environmental friendly Easy to operate & maintain by local community Long term sustainability

The main component of landfill gas are methane and carbon dioxide. Both components contribute significantly to the greenhouse effect and are chiefly responsible for global temperature rise.

RECOMMENDED APPROACHES TO WASTE MANAGEMENT

MSW Thermo-chemical Conversion Technologies

Recycling

Waste disposal technology improves over time as a result of :- Higher awareness of environmental, safety and health impacts More stringent requirement for compliance with emission

standards Land scarcity Drawing the most efficient recovery of energy from wastes Not least, escalating fuel prices which makes fossil fuel more

expensive for power generation Competitive cost of technology over time

Progress of Technology for Waste Destruction (Non-recyclable MSW)

1 ton of solid waste generate 200 – 300 m3 of landfill gas

1 m3 of landfill gas contains 0.5 m3 of natural gas which could be used as a fuel to generate 5 kWh energy.

1 ton of CH4 after combustion will generate 24 ton of CO2

Source : Juniper Consultancy Ltd., UK. “Progress Towards Commercialising Waste Gasification” A World Wide Status Report : Presentation to the Gasification Technology Conference : San Francisco USA 2003 and secondary market information

≤ 5,000c

≤ 1,250c

≤ 1,200c

≤ 700c

-

Advanced Thermal Gasification System

Fixed or Fluidised Bed Gasification

Incineration

Burning (Furnace)

Landfill

Waste Destruction Energy Generation

Waste Destruction Energy Generation

Waste Destruction

Landfill

Waste Disposal Landfill

WasteDisposal

- Dump Site Waste Disposal

No GHG “Zero” Landfill

No GHG Landfill/Ashes

GHG, Dioxin/Furan Landfill/Ashes

GHG, Dioxin/Furan Ashes

GHG Leachate

GHG Leachate

Temp. Technology Selection Outcome Environmental Issues

Tech

no

logy

Evo

luti

on

Progress of Technology for Waste Destruction

Combustion Types

• Incineration (energy recovery through complete oxidation) Mass Burn Refuse Derived Fuel (RDF)

• Pyrolysis • Gasification • Plasma arc (advanced thermal conversion)

Technology improvement naturally draws increased capital cost but … the environmental and health improvements supersede the conventional waste disposal technology

Dumping Landfill Sanitary Landfill

Incinerator Gasification Advanced

Thermal Gasification

System Water source contamination

Air pollution impacts

Overall environmental costs

Various waste disposal technologies

Uncontrolled leachate: high risk of water contamination

Moderate risk of water contamination

Controlled leachate: Minimised water contamination

Moderate to high risk of air pollution from methane

Moderate risk of air pollution from methane

Risk of air pollution from furans & dioxins presents

No risk of air pollution

Prospect for energy recovery No prospect of recovery of energy

waste

Minimal prospect of recovery of energy from waste

HIGH

High prospect of recovery of energy waste (energy recovery is maximised)

MODERATE LOW NEGLIGLIBLE

Tipping Fees per Ton

Benefits of WTE

Incineration

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

Carbon and Energy Considerations

System Components

• Refuse receipt/storage

• Refuse feeding

• Grate system

• Air supply

• Furnace

• Boiler

A Waste-to-Energy Incinerator with Pollution Controls

Flue Gas Pollutants Particulates Acid Gases NOx

CO Organic Hazardous Air Pollutants Metal Hazardous Air Pollutants

Particulates Solid Condensable Causes Too low of a comb (incomplete comb) Insufficient oxygen or overabundant EA

(too high T) Insufficient mixing or residence time Too much turbulence, entrainment of

particulates Control

1) Cyclones - not effective for removal of small particulates

2) Electrostatic precipitator 3) Fabric Filters (baghouses)

Metals Removed with particulates Mercury remains volatilized Tough to remove from flue gas Remove source or use activated carbon (along with dioxins)

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

1) Wet scrubber 2) Spray dryer 3) Dry scrubber injectors

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

Pollution Controls

Air Pollution Control

• Remove certain waste components

• Good Combustion Practices

• Emission Control Devices

Electrostatic Precipitator Bag-houses Acid Gas Scrubbers Wet scrubber Dry scrubber Chemicals added in slurry to neutralize acids

Activated Carbon Selective Non-catalytic Reduction

Schematic Presentation of Bottom Ash Treatment

1. Construction fill 2. Road construction 3. Landfill daily cover 4. Cement block production 5. Treatment of acid mine drainage

Ash Reuse Options 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

Pyrolysis

Pyrolyzer—Mitsui R21

Thermal degradation of carbonaceous materials Lower temperature than gasification (750 – 1500oF) Absence or limited oxygen Products are pyrolitic oils and gas, solid char Distribution of products depends on temperature Pyrolysis oil used for (after appropriate post-treatment):

liquid fuels, chemicals, adhesives, and other products.

A number of processes directly combust pyrolysis gases, oils, and char

Example: Fulcrum Bioenergy MSW to Ethanol Plant:

Construction on Fulcrum Bio-energy municipal solid waste to ethanol plant, Sierra Bio-Fuels, started in 2008. Located in the Tahoe-Reno Industrial Center, in the City of McCarran, Storey County, Nevada, the plant convert 90,000 tons of MSW into 10.5 million gallons of ethanol per year.

pyrolysis

Gasification

Flexibility of Gasification

Thermo-select (Gasification and Pyrolysis)

• Recovers a synthesis gas, utilizable glass-like minerals, metals rich in iron and sulfur from municipal solid waste, commercial waste, industrial waste and hazardous waste

• High temperature gasification of the organic waste constituents and direct fusion of the inorganic components.

• Water, salt and zinc concentrate are produced as usable raw materials during the process water treatment.

• No ashes, slag or filter dusts • 100,000 tpd plant in Japan operating since 1999

Thermoselect (http://www.thermoselect.com/index.cfm)

□ Utilizes Thermal Energy developed by Plasma Torches at Temperatures ≤5,500 Degrees Celsius

□ Multiple Feedstock

□ All Organic Material is Gasified to form a Synthetic Gas (“Syngas”)

□ All Inorganic Materials is Vitrified into Inert “High Grade Aggregate Slag”

□ Calorific Energy and Sensible Heat from the Syngas is Recovered and transformed into Electrical Energy

Advanced Thermal Gasification System

Conclusions • Combustion remains predominant thermal

technology for MSW conversion with realized improvements in emissions

• Gasification and Pyrolysis systems now in commercial scale operation but industry still emerging

• Advanced Thermal Gasification System is Clean Development Mechanism under Kyoto Protocol. Capable for qualification as CDM project, i.e., reduction of emission of methane typically from landfills and reduction of CO2 emission from avoidance of use of fossil fuels for power generation.

• Improved environmental data needed on operating systems

• Comprehensive environmental or life cycle assessments should be completed