Selection of HCRW Treatment Technologies for Gauteng

1
Selection of HCRW Treatment Technologies for
Gauteng

• David A Baldwin, PhD, Pr.Sci.Nat.
• Environmental and Chemical Consultants cc
• and
• Torben Kristiansen
• Chief Technical Advisor. Gauteng Department of
  Agriculture, Conservation, Environment and Land
  Affairs
• Rambøll, Hanneman and Hojland
• August 2003

2
Introduction

• Status Quo Study into HCRW in Gauteng 2000
• Confirmed parlous state of HCRW management in
  Gauteng
• Treatment facilities included 70 incinerators at
  58 different locations
• Only 58 were operational but only 25 had a
  permit
• Many incinerators were poorly operated and
  maintained
• Only one fitted with emission control equipment,
  which was not operational
• Capital and operating costs were estimated at
  only R1.00 per kilogram of waste treated

3
Introduction to Technologies -1

• Thermal treatment/combustion technologies
• Incineration which includes
• excess air,
• controlled air,
• rotary kiln and
• fluidised bed
• Plasma Arc and
• Pyrolysis

4
Introduction to Technologies -2

• Sterilisation/Disinfection Technologies,
• Steam sterilisation, e.g. Autoclaving
• Chemical sterilisation, e.g. with chlorine,
  glutaraldehyde
• Gas sterilisation, e.g. with ethylene oxide,
  formaldehyde
• Dry heat sterilisation, e.g. oil heated screw
  feed technology
• Electro-thermal deactivation (ETD),
• Microwave sterilisation,
• Irradiation sterilisation
• Cobalt-60 gamma rays
• Ultra violet
• Electron beam sterilisation

5
Waste Pathway for Incineration
Infectious waste Sharps
Ash
Landfill
Leachate
Flue gas cleaning residues
Pathological Waste
Incineration
Chemical Waste
Emissions to Air
6
Waste Pathway for Non-Burn Technologies
Leachate Gas Emissions
Non-infectious waste
Infectious waste Sharps
Non-Burn Treatment
Landfill
Incineration Cremation or Burial
Ash or Body Parts
Pathological Waste
Cemetery
Treatment as Hazardous Waste
Waste Treatment Residues to Landfill
Chemical Waste
7
Flow Diagram of Modern Incineration Plant
8
Advantages of Incineration

• Safe elimination of all infectious organisms in
  the waste at temperatures above 700oC
• Flexible, as it can accept pathological waste and
  depending on the technology chemical waste.
• Residues are not recognisable
• Reduction of the waste by up to 95 by volume or
  83 to 95 by mass typically 5-17 ash is
  obtained.
• Very well proven technology
• No pre-shredding required
• No special requirements for packaging of waste
• Full disinfection is assumed to have occurred
  provided the high temperatures are maintained and
  the ash quantity is adequate. No monitoring of
  sterilisation efficiency is required.

9
Disadvantages of Incineration

• Normally higher investment costs required for
  incinerator and flue gas cleaning compared to
  non-burn technologies
• Point source immediate emissions to the air (as
  opposed to attenuated emission of CH4 and CO2
  from landfill body over a period of decades)
• High cost of monitoring gas emissions and
  demonstrating compliance to emission standards.
• Solid and liquid by-products must be handled as
  potentially hazardous waste (may not apply to
  bottom ash if waste is well sorted and FGC
  residues handled separately)
• Incineration is perceived negatively by many
  sections of the community.
• PVC and heavy metals in the waste provide a
  significant pollutant load on the gas cleaning
  system and for heavy metals on the quality of
  bottom ash
• Existing health care risk waste incinerators in
  South Africa cannot accept significant amounts of
  chemical waste because of refractory damage.

10
Flow Diagram a Typical Microwave Plant
11
Advantages Non-Burn Technologies -1

• Autoclaving, Microwaving ETD and DHS (Cross
  cutting)
• High sterilisation efficiency under appropriate
  conditions
• Low temperature of operation 90oC to 160oC
• Volume reduction depending on type of
  shredding/compaction equipment that has been
  installed
• Low risk of air pollution
• Moderate operation costs
• Easier to locate as generally more acceptable to
  communities and neighbours than incineration
• Recovery technologies can be used on sterilised
  waste

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Advantages Non-Burn Technologies -2

• Autoclaving
• Proven system that is familiar to health-care
  providers
• Relatively High Sterilisation Temperature
• Microwaving
• Low capacity units are available for small waste
  producers e.g. clinics and GPs
• Moderate investment costs
• Low Sterilisation Temperature may lower energy
  costs
• Electro-thermal Deactivation
• Low Sterilisation Temperature may lower energy
  costs

13
Disadvantages Non-Burn Technologies -1

• Autoclaving, Microwaving ETD and DHS (Cross
  cutting)
• Not suitable for pathological waste and chemical
  waste
• Good waste segregation required
• No or limited mass reduction
• Shredders are subject to breakdowns and blocking
  and repairs are difficult when the waste is
  infectious.
• It is not possible to visually determine that
  waste has been sterilised
• Waste is not rendered unrecognisable or unusable,
  if not shredded
• High monitoring costs to demonstrate compliance
  with sterilisation standards
• Treated waste must be disposed to landfill
• Air filtration is needed some odour problems
• Operation requires highly qualified technicians.
• HEPA filters must be maintained and replaced
  regularly

14
Disadvantages Non-Burn Technologies -2

• Autoclaving
• Significant amounts of volatile organic carbon
  compounds produced
• Contaminated water must be discharged to sewer
• Waste and containers must have good steam
  permeability, especially if there is no prior
  shredding
• No waste reduction
• Microwaving
• Unsuitable for very high quantities of infected
  metal (e.g. needles from inoculation campaigns)
• Low sterilisation temperature increases time
  required for treatment.
• Electro-thermal Deactivation
• Relatively high investment and operating costs
• Low sterilisation temperature increases time
  required for treatment.

15
Cost Comparison of Selected HCRW Treatment
Technologies - 1

• Assumptions
• Salary costs include all normal contributions
• The cost for the establishment of a building in
  the estimated costs.
• A standard fixed amount for consultancy fees and
  other expenditure required to obtain an EIA
  authorisation, etc
• The cost of equipment was based on
  International/South African price levels for
  delivery in Gauteng.
• Incinerators include gas-cleaning equipment, i.e.
  lime treatment plus a ceramic filter.
• The cost of civil works and installation were
  based on Gauteng prices

16
Cost Comparison of Selected HCRW Treatment
Technologies - 2

• Economic life of civil works and treatment
  technologies 12 years
• Economic life of storage and transportation
  equipment 10 years
• The following costs not included
• Infrastructure at the generators site,
• Establishment of public utilities used, e.g.
  landfills
• Cost of administration, invoicing, marketing etc.
• Cost of training of operators
• Cost of PPE/OSH programmes.
• Value Added Tax.
• Depreciation costs are estimated as 10 years for
  equipment and 15 years for other capital and a
  real interest rate of 12 p.a.

17
Cost Comparison of Selected HCRW Treatment
Technologies - 3

• The operational hours for the plants were based
  on operation for 26 days per month and 12 months
  per year. However, the maximum operational hours
  were varied as follows
• Incinerators lt 200kg/hr 12 hrs per day - manual
  de-ashing
• Incinerators ? 200kg/hr 20 hours per day -
  automatic de-ashing
• Non-burn Technologies 24 hours per day
• The costs for disposal of residues, such as the
  ash and gas cleaning waste from incinerators, and
  sterilised the waste from non-burn technologies,
  were estimated using current disposal costs.
  Residues from non-burn are assumed deposited at
  normal landfill sites, whereas residues from
  incinerators are assumed deposited at a Hazardous
  Waste Landfill site.
• For non-burn technologies an estimate of the
  costs of disposal of pathological waste and
  chemical waste that could not be treated by the
  technology was included

18
Costs for HCRW Treatment Technologies
Technology Capacity, kg/hr Investment Cost, R m Running Cost, R m R/kg
Microwaving 100 5.83 2.33 3.27
  5.83 7.40 3.10 1.95
  2.33 10.61 5.09 1.08
Autoclaving 3.27 4.84 1.82 3.03
  250 6.34 2.55 1.34
  7.40 9.90 5.14 1.71
Incineration 3.10 3.96 1.66 5.55
  1.95 5.16 2.49 2.00
  1000 7.42 4.53 0.97
Running Costs Interest Depreciation on Capital Operating (monitoring excluded) Running Costs Interest Depreciation on Capital Operating (monitoring excluded) Running Costs Interest Depreciation on Capital Operating (monitoring excluded) Running Costs Interest Depreciation on Capital Operating (monitoring excluded) Running Costs Interest Depreciation on Capital Operating (monitoring excluded)
19
Cost of HCRW Technologies

• Treatment cost decreases dramatically as plant
  capacity increases
• For incineration, there is a discontinuity that
  occurs below 200kg/hr due to the assumptions made
• The costs are based on operating the facility at
  its maximum capacity.
• According to the available data, microwaving is
  relatively expensive but the costs become
  comparable at higher loads.
• The investment costs for incineration appear to
  be relatively low compared to the other two
  technologies.

20
Testing and Monitoring Incineration Plants - 1

• Requirements
• Performance Testing to conform to ROD
• Standard Testing at least over first year of
  operation
• Minimum Programme once prove conformance
• Analysis Required
• Continuous Monitoring of PM, carbon monoxide,
  oxygen, water vapour, hydrochloric acid and
  sulphur dioxide
• Dioxins Performance x 1 Standard 2/yr
  Minimum 1/yr
• Metals Performance x 1 Standard 2/yr Minimum
  1/yr
• Loss on Ignition for Ash Performance x 1
  Standard and Minimum 12/yr

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Testing and Monitoring Incineration Plants - 2
Performance Analysis Standard Analysis Minimum Analysis
Performance Analysis Standard Analysis Minimum Analysis
Capital Cost R868,000 R868,000 R868,000
Depreciation R1,041,000 R1,041,000 R1,041,000
Running Cost R90,000 R370,000 R283,00
22
Testing and Monitoring Incineration Plants - 3
Waste Throughput, kg/hr Standard Programme Standard Programme Minimum Programme Minimum Programme
Waste Throughput, kg/hr Treatment Cost R/kg Monitoring Cost as Treatment Cost R/kg Monitoring Cost as
100 7.09 22 6.49 14
250 2.37 16 2.22 9.0
500 1.43 8.2 1.36 6.2
1000 1.00 7.0 0.96 4.0