sustainable report - final.pdf

8/14/2019 Sustainable Report - Final.pdf

1/31

Newcastle University (SG) Chemical Engineering

Assignment Submission & Feedback Sheet

Student name:Wong Jie WeiShawn GallatinSamuel Lee Mao HuaJean Zhou Li Ting

Ng Xiao YuanJasmine Tan Lian Fang

Student No:110526001110525026110525004110526539110524856110522298

Year:2012 Submittedto:Ms SharonJoyce

Marked by:

Module Code:

CME3113

Module Title:Sustainable Industries

Assignment title:Waste Management Strategy for Singapore(Potential Investors)

Date

submitted :28 Nov 12

Date

returned:

Blackboard Paper ID:

I certify that all material in this course which is not our own work has been

identified.

Student Signature:

Student self-evaluation:

(1) A strong point of our assignment:- Managed to cite actual case studies and related to Singapores context inmonetary terms

(2) An area which we believe may need improvement:- Analysis in terms of financial sustainability may not be sufficiently critical

(3) We would particularly like your feedback/help with:List up to two specific areas:

- Whether the analysis were sufficiently critical and if the report was conciseenough

Markers comments:

Overall mark:70100 1

stClass

6069 2 - 15059 2 - 24049 3rd0 - 39 Fail


2/31

CME 3113

Sustainable Industry

Potential Investor

(Cohort 1)

Team Members:

Wong Jie Wei (110526001)

Shawn Gallatin (110525026)

Samuel Lee Mao Hua (110525004)

Sim Jiaxuan (110525680)

Jean Zhou Liting (110526539)

Ng Xiao Yuan (110524856)

Jasmine Tan Lian Fang (110522298)


3/31

School of ChemicalEngineering &Advanced Materials

Potential Investor

i

Executive Summary

Five waste management strategies (Incineration, Pyrolysis & Gasification, Improved

Recycling, Anaerobic Digestion and Composting) were analysed based on the

investors point of view. Capital and operating costs of the mentioned waste

management, including its profitability for a period of 10 years were concluded using

cumulative cash flow diagrams. The results showed that both incineration and

Thermoselect took 7 years to break even. However, incineration had a higher

cumulative cash flow of SGD 1069.989M vis--vis Thermoselect which had a

cumulative cash flow of SGD 692.37M at the end of 10 years. Therefore, incineration

was chosen as it was the most economically sustainable waste management strategy

which offered the highest returns on investment in the same period.

(1884 words inclusive of executive summaryexcluding tabulated texts and appendices)


4/31


Potential Investor

ii

List of Illustrations

Figure 1 Cash Flow Diagram for Thermoselect ............................................................ 4

Figure 2 Sensitivity Analysis of Syngas Production (Khoo H.H. et. al., 2006) ............ 4

Figure 3 Cash Flow Diagram for Anaerobic Digestion ................................................. 5

Figure 4 Trend of Fertilizer Use in Singapore (TradingEconomics.com, 2012) ........... 6

Figure 5 Cash Flow Diagram for Composting ............................................................... 7

Figure 6 Cash Flow Diagram for Improved Recycling ................................................. 9

Figure 7 Relationship between commodity prices and profit (Fabian B & Mathias S.,

2012) ............................................................................................................................ 10

Figure 8 Cash Flow Diagram for Incineration ............................................................. 11

Figure 9 Factors Affecting Treatment Cost and Subsequently Revenue (Decision

Makers Guide To Municiple Solid Watse, 1999) ........................................................ 12

Figure 10 Prices of Ferrous Metals (Letsrecycle: Metal, 2012) .................................. 13

List of Tables

Table 1 Comparison between Incineration and Thermoselect (Khoo H.H et. al., 2006)

........................................................................................................................................ 3

Table 2 Estimated Costs of Anaerobic Digestion Facilities to Process Mixed Waste

(Cant, 2006) ................................................................................................................... 5

Table 3 Summary of Finances (Steve R.S et al, 2002) .................................................. 6

Table 4 Summary of finances obtained (SembcorpBusiness at a glance) ................. 8

Table 5 Summary of Finances of TSIP ........................................................................ 10

Table 6 Prices of Ferrous Metal Recyclates in Year 2011 (Letsrecycle: Metal, 2012)

...................................................................................................................................... 12

Table 7 Summary of the Economic Analysis of All Technologies ............................. 14


5/31


Potential Investor

iii

Table of Contents

1. Introduction .......................................................................................................... 1

2. Methodology .......................................................................................................... 2

3. Market Survey ...................................................................................................... 3

3.1 Thermoselect ....................................................................................................... 3

3.1.1 Investment Analysis ...................................................................................... 3

3.1.2 Sensitivity Analysis ....................................................................................... 4

3.2 Anaerobic Digestion ........................................................................................... 5



3.3 Composting ......................................................................................................... 6



3.4 Improved Recycling ............................................................................................ 8


3.4.2 Sensitivity Analysis ..................................................................................... 10

3.5 Incineration & Landfill ..................................................................................... 10

3.5.1 Investment Analysis .................................................................................... 10

3.5.2 Sensitivity Analysis ..................................................................................... 12

4. Conclusion ........................................................................................................... 14

5. References ............................................................................................................ 15

6. Appendices .......................................................................................................... 18

6.1 Appendix A ....................................................................................................... 18

6.2 Appendix B ....................................................................................................... 20

6.3 Appendix C ....................................................................................................... 22

6.4 Appendix D ....................................................................................................... 24

6.5 Appendix E ....................................................................................................... 26


6/31


Potential Investor

1

1. Introduction

With a population density of approximately 5.3 million ("Statistics," 2012) and

limited land area, it is imperative that Singapore has an efficient system for the

collection and disposal of solid waste. Over the years, the output of solid waste in

Singapore has increased from 4.6 million tons in 2000 to 6.8 million tons in 2011.

(Tay, 2012) Statistical data showed that 59% of the total waste generated 2011 was

being recycled. Out of the 41% that was disposed of, 38% goes to the Waste-to-

Energy (WTE) plants where the waste will be incinerated and the energy recovered.

The remaining 3% along with the unwanted residue from the incineration would be

sent to the Semakau Landfill for landfilling. (Tay, 2012)

At present, the frequency of Singapore building a new incineration plant is one every

5-7 years. (McCrea et al.)With that, the cost involved in dealing with the wastes in

Singapore will be constantly increasing as the rate of waste generation increases with

respect to the growing population. Hence, it is important that a new waste

management strategy is developed in order to accommodate the growing volume of

waste. This new strategy should not only be a long term solution to Singapores

growing waste problems, it should also offer attractive returns; one that is worth

investing in.


7/31


Potential Investor

2

2. Methodology

i. The existing waste management strategies in Singapore were analyzed.ii. Research was done on other forms of waste treatment. Research areas were,

- Incineration- Pyrolysis & Gasification- Improved Recycling- Anaerobic Digestion- Composting

iii. Factors such as the capital and operating costs of the plant as well as themarket value of any saleable products were gathered for the respectiveresearch areas.

iv. With the data, an estimation of the profitability and feasibility of each wastetreatment process was analysed.

v. The profitability of each waste treatment process was projected for 10 yearsthrough the use of a cumulative cash flow diagram.

vi. At the same time, wastes generation and recycling patterns were studied todetermine whether it would be worthwhile to be investing in the waste

management business.

vii. From the cash flow diagrams, a comparison was done to decide which wastemanagement process would give the best return on investments.

viii. Finally, a simple risk analysis (sensitivity) of the investment was conducted toinvestigate the effects of various external undesirable factors on the revenue or

operating conditions/costs.

In each of the technologies discussed, a brief description of the technology and some

detailed financial data (if available) are attached in Appendices A-E while the general

finance related materials are discussed in the report.


8/31


Potential Investor

3

3. Market Survey

3.1 Thermoselect

3.1.1 Investment Analysis

Presently, the main waste treatment is by incineration. Comparatively, countries such

as Japan and Germany have ventured into Thermoselect, a plant which features

cleaner emissions, higher efficiencies and greater investment returns.

A study by the Institute of Chemical and Engineering Sciences was conducted to

ascertain the economical viabilities of Thermoselect in Singapore. It was based on a

plant in Europe which had the same capacity of the Waste to Energy Incinerator in

Tuas South.

Table 1 summarizes the cost and operating conditions related to that of the Tuas

Incinerator and the proposed Thermoselect plant.

Table 1 Comparison between Incineration and Thermoselect (Khoo H .H et. al., 2006)

Cost and Operating ConditionsWaste Treatment Technology

Incinerator Thermoselect

Capacity (tpd) 3000 3000

Type of materials processed Mixed MSW Mixed MSW

Main useful product Electricity(550KWh/ton)

Syngas (890kg/ton)

Capital and construction costs in

millions SGD900 725

Operating costs in SGD/ton 70 100

Tipping fee in SGD/ton

(Source: Cooper J, 2010)80 80

Disposal cost to landfill in SGD/ton 77 77

Electricity Input (KWh/ton) 70 302

Natural gas input (m3/ton)

(Source: Smart Energy)0.23 34.6

Residues/Ash Up to 20% Up to 5%

From Table 1, it was shown that the Thermoselect plant was much cheaper to build as

compared to the Incinerator. However, the operating cost was slightly higher

comparatively than the incineration plant.


9/31


Potential Investor

4

Figure 1 Cash Flow Diagram for Thermoselect

From Fig. 1, it could be seen that it will take approximately 7 years to break even and

that the cumulative cash flow at the end of 10 years would be SGD 692.4M.

3.1.2 Sensitivity Analysis

Figure 2 Sensitivity Analysis of Syngas Production (Khoo H .H. et. al., 2006)

From Fig. 2, it can be seen that low production rates of syngas would increase break

even time required for recovery of capital cost. However, higher production of syngas

may not reduce the break even time required as the operating costs increases with

production rates.

-800

-600

-400

-200

0

200

400

600

800

0 1 2 3 4 5 6 7 8 9 10

CummulativeCashFlow(MS

GD)

Year

Cash Flow Diagram


10/31


Potential Investor

5

3.2 Anaerobic Digestion


Municipal solid waste can be treated using a process known as anaerobic digestion.

From this process, biogas is produced, which is then combusted and used to drive gas

engines to produce electricity. The electricity was then sold to the grid. Additional

income from the tipping fee was also considered when calculating the overall revenue

of the plant.

Table 2 Estimated Costs of Anaerobic Digestion Facilities to Process Mixed Waste (Cant, 2006)

Costs Involved SGD

Capital Cost 1,5372,000

Annual Operating Costs

(including offsite curing

and residue disposal)

1,488,400

Annual Electricity

revenue1,215,000

Annual Tipping Fee

Revenue1,600,000

Using the estimated costs from Table 2, a cash flow diagram was generated to analyze

the profitability if this waste treatment process.

Figure 3 Cash Flow Diagram for Anaerobic Digestion

From Fig. 3, it was observed that the estimated time taken for the project to break

even would be slightly more than 12 years. This was due to the high capital and

operating costs of the facility. This meant that the project would not be profitable due

-18

-16

-14

-12

-10

-8

-6

-4

-2

0

0 2 4 6 8 10

Cumulativ

eCashFlow(MS

GD)

Year

Cash Flow Digram


11/31


Potential Investor

6

to a low return on investment. Hence, the use of anaerobic digestion as a waste

treatment process would not be attractive for investors.

3.2.2 Sensitivity AnalysisGiven the increasing waste generation trend, it is not expected that the production

rates and revenues would be affected.

3.3 Composting


While current practices in Singapore are limited to household scale, the neighbouring

countries such as Malaysia, Thailand and Philippines already have plants which

capitalize on the value of the composts.

Figure 4 Trend of Fertilizer Use in Singapore (TradingEconomics.com, 2012)

From Fig. 4, it could be noted that the trend of fertilizer use increasing and thus

presents a potential market to be surveyed for feasibility.

Table 2 summarizes the finances associated with the investment into

vermicomposting.

Table 3 Summary of Finances (Steve R.S et al, 2002)

Direct costs of operating the processing system

Expenses incurred at Waste Research Centre

(WRC)Cost per Block

Land Rental $200

Waste application and handling equipment $200

Screening/harvesting equipment $980

Utilities $200

Workshop rental $600

Labour $810

Depreciation of beds $1200


12/31


Potential Investor

7

($4190)

Potential Income (per Block)

WRC Income Worst case Best case

Compost sales (estimated 20 m3/yr) $600 $2400

Earthworm sales (estimated 50 kg/yr) $500 $1000($1100) ($3400)

Direct Processing Cost (per Block)

Details Worst case Best case

Direct processing costs $4190 $4190

Total income $1100 $3400

Net costs $3190 $790

Tonnes processed/year 52 52

Gate fee required to break even $62 $16

Estimated Overhead Cost (per Block)

Details Cost per Block

Staff costs $960Marketing/administration $300

Premises/facilities $300

Tonnes processed/year 52

Gate fee required to break even $30

Figure 5 Cash Flow Diagram for Composting

Fig. 5 was constructed from Table 3 to illustrate the cumulative cash flow. The plant

was constructed under slightly in a year and that with an operating cost of $3340 per

annum (due to the fixed capacity of the plant). From the CFD, it would take

approximately 2.2 years to break even and at the end of 10 years, the cumulative cash

flow would be SGD 32,340.

-6000

-1000

4000

9000

14000

19000

24000

29000

34000

39000

0 2 4 6 8 10CummulativeCashFlow(SGD)

Year

Cash Flow Diagram


13/31


Potential Investor

8


The costs of fertilizers in Singapore are relatively constant and are usually affected by

demands and transportation costs. This would then affect production cost and

subsequently the selling price of the product. As waste generation is on the rise

coupled with the increase in composting trends, it is not expected that the plant feed

rate would reduce and hence production efficiencies would not be affected.

However, as the market for the composts is small in Singapore, majority of the

products would have to be shipped to the neighbouring countries and by doing so

would then increase the gate fee & reduce the profit margin. With all the addition of

all the discussed components, the final selling price would be insufficiently

competitive even though the cost price and general benefits of composting are cheaper

and better than the inorganic fertilizers used alone.

3.4 Improved Recycling


Case studies of recycling firms were studied for its economic feasibility. However a

financial report for a recycling-only firm could not be obtained. This was because

most companies in Singapore incorporate collection and waste treatment. As such,

companies such as Sembwaste were used as the basis. Table 3 summarizes the

finances of Sembwaste in Year 2011.

Table 4 Summary of finances obtained (SembcorpBusiness at a glance)

Year 2011 Sembwaste

Total waste recycled

(tonnes/year)150,000

Revenue

(SGD in million)370.3

Profit(SGD in million)

42

Capital Cost

(SGD in million)328.3

Break even

(years)8.7

Based on Table 4, a 10-year cash flow diagram (Fig. 6) was computed to illustrate the

cumulative cash flow. The following assumptions were made in the computation;


14/31


Potential Investor

9

Increment of 1% in recycling rate. (According to NEAs waste report ofaverage increment of 1% throughout 10 years.) (ZerowastesgSingapore

Waste Statistics, 2011)

Not all waste collected are recycled.

Figure 6 Cash Flow Diagram for Improved Recycling

The waste statistics from National Environment Agency showed that the recycling

rate in year 2011 was 59% with the total waste recycled at 4,038,800 tonnes. From the

financial report of Sembwaste, it was noted that they only had a share of 2.2%

(150,000 tonnes) of the 59% of waste recycled in Singapore. This low percentage

proved that the potential for revenue is high; furthermore it is expected that the

recycling rates are to be increased.

From Fig. 6, it could be seen that it took 8.7 years to break even with a cumulative

cash flow of SGD 65.2M at the end of 10 years.

-400

-300

-200

-100

0

100

0 2 4 6 8 10

CumulativeCashFlow(MS

GD)

Year

Cash Flow Diagram


15/31


Potential Investor

10


Figure 7 Relationship between commodity prices and profit (Fabian B & Mathias S.,

2012)

From Fig. 7, it could be seen that the increase in amount of waste recycled could

affect the income. Similarly, the commodity price also affects the income as seen

from the gradients of the lines in Fig. 7 (commodity price being the gradient of the

lines). Hence, with the increasing trend in the commodity prices coupled with the

increase in waste generation, it is not expected that business would be affected by a

reduction in waste processing rate.

3.5 Incineration & Landfill


The total waste generated in Singapore was 6.8 million tonnes in 2011 with a

projected increment of approximately 5.37% per year due to population growth and

increasing effluence. (Solid Waste management, 2012)

Table 5 summarizes the approximated finances for the processing of 2.3 million

tonnes of waste per annum.

Table 5 Summary of Finances of TSIP

Spending Avenue Rate Generation/Production Cost per Annum

- Capital Cost S$890M NA NA

- Waste Generated to

TSIP

NA 2.3Mil ton/yr NA

- Operation Cost S$70/ton NA -S$161M

- Landfill fee S$77/ton 0.066Mil ton/Yr -$5.13M


16/31


Potential Investor

11

Revenues

- Electricity sold S$0.27/kWh 64MW S$151.4M

- Ferrous Metal sold S$270 0.39Mil tonne/yr S$105.3M

- Tipping Fee S$80/tonne 2.3Mil tonne/yr S$184M

Net Profit less Capital S$440.7M

Figure 8 Cash Flow Diagram for Incineration

From Fig. 8, it will take approximately 6.8 years to break even with a cumulative cash

flow of S$ 1070M at the end of 10 years.

From the Table 5, it was observed that the tipping fee contributed to the biggest

portion of the revenue. The tipping fee was calculated based on weight of the waste

and would hence increase as the waste generation increases.

Recovered ferrous metal could be sold to local steel mills. The resale of ferrous metal

only contributes to 24% of the whole revenue generated. The total recovered metalswas 0.39 million tonnes in year 2011. (Solid Waste management, 2012) The average

price for ferrous metal of S$270/tonne was derived from Table 6.

Recently a potential market in the bottom ash produced from incineration was found

for use in concrete. As the bottom ash is very porous, concrete made from bottom ash

is lighter than those made from natural gravel which helps in lowering the

transportation cost. For this reason, more construction businesses have switched to

bottom ash for use in concrete. This reduced the cost of land filling the bottom ash by

-890

-640

-390

-140

110

360

610

860

1110

1360

0 2 4 6 8 10

CummulativeCashFlow

(M

SGD)

Year

Cash Flow Diagram


17/31


Potential Investor

12

15-20% which was estimated to be $22/tonne from the current $25/tonne. (Heiner

Zwahr)

Table 6 Prices of Ferrous Metal Recyclates in Year 2011 (Letsrecycle: M etal, 2012)


The energy recovered from the incineration of wastes is also reliant on the calorific

value of the waste. Figure 9 shows how the calorific value and working capacity

would affect production cost and subsequently revenue.

Figure 9 Factors Affecting Treatment Cost and Subsequently Revenue(Decision Makers Guide To Municiple Solid Watse, 1999)


18/31


Potential Investor

13

From Fig. 10, it was observed that revenue would not be affected significantly despite

the decline in the prices of ferrous metals due to the increase in waste generation per

year.

Figure 10 Prices of Ferrous Metals (Letsrecycle: M etal, 2012)


19/31


Potential Investor

14

4. Conclusion

Amongst the explored technologies available for proposal in the survey, a Table 7 was

constructed to aid in decision making process for the final selection of the technology

for investment.

Table 7 Summary of the Economic Analysis of All Technologies

Technology Indicators Performance

Thermoselect

Breakeven period 7 years

Cumulative Cash @ 10 year SGD 692.37M

Risk (Sensitivity) High

Anaerobic Digestion

Breakeven period 12 - 13 years

Cumulative Cash @ 10 year SGD -3.433M

Risk (Sensitivity) Low

Composting


Cumulative Cash @ 10 year SGD 25,135

Risk (Sensitivity) Medium

Improved Recycling




Incineration




It is clear from Table 7 that Thermoselect, Composting and Incineration were

promising technologies which would be profitable with a reasonable period to

breakeven. Both Thermoselect and Incineration broke even at the 7th year mark and

were low in investment risk. However, at the 10thyear of investment, it could be seen

that Incineration had the highest cumulative cash flow which meant higher return on

investment. Furthermore, the Thermoselect technology was assessed to be high in risk

compared to Incineration, with only low risk.

Therefore, Incineration was chosen for the ideal waste management technology for

Singaporebusiness as usualfrom an investors point of view for an economically

sustainable investment.


20/31


Potential Investor

15

5. References

Benefits-of-Recycling:Recycling Prices. What is the Cost of Recycling?Available at: http://www.benefits-of-recycling.com/recyclingprices/

(Accessed: 30/09/12)

Business Week: Veolia environment-adr (VE:Singapore).Available at:http://investing.businessweek.com/research/stocks/financials/financials.asp?tic

ker=VE:SP

(Accessed: 1/11/12)

Cant, M. (2006, April). Municipal solidwaste (MSW) options: Integratingorganics management and residual treatment/disposal.

Cooper, J (2010) Singapores Tuas Incinerator Officially Opened. Availableat: http://www.letsrecycle.com/news/special-reports/singapores-tuas-

incinerator-officially-opened.

(Accessed 10/11/12)

Eco-Business:Recycling in Singapore: 10 years onChute, we got it wrong.Available at:http://www.eco-business.com/news/recycling-singapore-10-years-chute-we-got-it-wrong/

(Accessed: 1/11/12)

Fabian B. & Mathias S. (2012)Economic Feasibility of e-Waste Treatment inTanzania, pg25, Swiss Federal Institute for Material Science and Technology

(EMPA),Switzerland.

Heiner Zwahr: Ash Recycling: Just A Dream? Available athttp://gcsusa.com/pdf%20files/Ash%20Recycling%20%20Just%20a%20Drea

m.pdf

(Accessed 14/11/12)

Khoo H.H, R. Tan B.H, Salim S. & Wu Y.M (2006)Life cycle evaluation andeconomic considerations of the pyrolysis-gasification of municipal solid waste

in Singapore, pg 46, Institute of Chemical and Engineering Sciences,

Singapore.

Letsrecycle: Metal. Available at:http://www.etsrecycle.com/prices/metals

(Accessed 14/11/12)


21/31


Potential Investor

16

Mewr: Solid Management . Available at:http://app.mewr.gov.sg/web/Contents/contents.aspx?ContId=680

(Accessed 12/11/12)

NEA:Envision. Available at:http://www.nea.gov.sg/cms/sei/Envision_11Jan_Issue1.pdf


NEA: Waste Minimisation & Recycling. Available athttp://app2.nea.gov.sg/topics_wasteminimisation.aspx

(Accessed: 9/10/12)

Sembcorp:Business at A Glance. Available at:http://www.sembcorp.com/en/investor-relations-businesses-glance.aspx


Sembcorp: Solid Waste Management. Available at:http://www.sembcorp.com/en/global-presence.aspx?type=waste


Singapore Power: Tariff Rates. Available athttp://www.singaporepower.com.sg/irj/portal?NavigationTarget=navurl://41c8

e6a3faf48bb168af2c222faa8ee4&windowId=WID1353506908214


Smart Energy: Current Price. Available at:http://www.smartenergy.sg/SMART_Energy/Welcome.html

(Accessed on: 15 Nov 2012)

Steve R.S & Jim F (2001) Vermicomposting Financial Evaluation and MarketProtential, pg 68-71, Urban Mines Pte Ltd

Trading EconomicsFertilizer Use in Singapore. Available at:http://www.tradingeconomics.com/singapore/fertilizer-consumption-metric-

tons-wb-data.html


Worlds Bank: Decision Makers Guide To Municiple Solid Watse Availableat:

http://web.mit.edu/urbanupgrading/urbanenvironment/resources/references/pdf

s/DecisionMakers.pdf (Accessed 14/11/12)

World-Wire:Recession Proof Cleantech Investing: The Recycling Industry.Available at: http://world-wire.com/news/0804010002.html (Accessed:

9/10/12)


22/31


23/31


Potential Investor

18

6. Appendices

6.1 Appendix A

Incineration

Introduction

Incineration is a thermal disposal technique that combusts waste with excess of

oxygen. There are currently 3 incineration plants in Singapore. The Tuas South Waste

to Energy Incineration plant would be discussed in this report.

The plant has six refuse cells with a capacity of 3000 tonnes per day. Steam is

generated from each boiler with a capacity of 105 tonnes/hr at a pressure of 35barg

and temperature of 370C. The diesel requirement for cold start-up of the plant is

5000L/boiler. Cold start-ups are only performed if the plant requires to be shut down

for maintenance otherwise the refuse are capable of sustaining the combustion itself.

The plant is rated at 80MW using a 10.5kV generator. 20% of the electricity produced

is used by the plant while the remaining 80% is sold. Incineration can achieve up to

90% and 75% reduction in volume and weight respectively. Digital control systems in

the central control room are used to monitor and control the processes to ensure

optimum efficiency and reliability.

Capital Cost refers to the amount of capital required to build the plant which in this

case is approximately S$890M. The construction of the incineration plant took four

years.

Operating cost includes the maintenance cost and the labour cost. An estimated

operating cost would be S$70/tonne of waste received. Landfilling contributes to a

fraction of the operating cost as the company is responsible for the disposal of waste

that cannot be incinerated. A cost of S$77-S$80 (Cooper J, 2010) would be incurred

by the company for every tonne of waste that is sent for landfill.

Energy can be recovered from hot water, low grade steam or super-heated steam.

Price of electricity is $0.27 per kWh in Singapore. Electricity generated by the plant is

dependent on the amount of waste generated.


24/31


Potential Investor

19

Process

The most important process to obtain electricity in the incineration plant is the heat

generated by the combusting the refuse. The heat from combustion is used to generate

steam in boilers. Electricity is generated by two steam turbines that are driven by the

steam. Used steam from the two turbines is condensed by air condenser fans. This

condensate would then be recycled back into the boiler.

Figure A1 Process Flow of TSIP


25/31


Potential Investor

20

6.2 Appendix B

Thermoselect

Introduction

Figure A2 Process Flow of Thermoselect (Yamada S. et. al., 2004)

Figure A2 shows the typical flow of Thermoselect process. Wastes are compressed

dried and pyrolyze by indirect heating in a degassing channel. The products are then

charged into high temperature reactor, where it is melted under controlled amount of

oxygen and pyrolyzed carbon to form gas. The gas is treated with gas reforming /

refining / quenching processes before being recovered as clean synthesized fuel gas or

syngas.

Process Features

The features are as follows:

- Low emissions of dioxins and no generation of fly ash- Increase in use of recyclates

The waste input is being processed into synthetic gas metals recovered, i.e.

granulated slag, metal hydroxides and mixed salts. Most substances are

used effectively as resources and results in minimum waste disposal.

- Gas ProductsThe key components of syngas are H2and CO, which can be used as fuel

and also as chemical feedstock. Syngas is applicable to a wide range of

power generation technologies such as the gas turbine combined cycle.

Syngas can be sold


26/31


Potential Investor

21

- Process EconomyThe process uses the energy contained in waste to perform melting and

remove the need for treatment processes for dioxins and fly ash with heavy

metal impurity. Due to the efficiency, total cost is lower than conventional

methods employed such as incineration first followed by ash melting. As

the process also minimizes the need for landfill, tipping fees are generally

reduced.


27/31


Potential Investor

22

6.3 Appendix C

Improved Recycling

Introduction

In the late 1990s, Singapore introduced measures such as recycling in order to cope

with the increasing waste generation and depleting land space for landfilling.

Recycling is the process of re-using solid waste materials and re-manufacturing it so

that it could be used again. This conserves landfill space and prevents wasting of

useful materials.

The wastes are collected and distributed to the sorting centers for processing. The

process will vary with different waste materials. Waste statistics from NEA showed

that current recycling method can recycle 13 types of wastes as shown in Table A1.

[NEA: Waste Statistics]:

Table A1 Types of Waste Recycled

Waste Type

1 Construction Debris

2 Used Slag

3 Ferrous Metal

4 Non-ferrous Metals

5 Scrap Tyres

6 Wood/Timber

7 Paper/Cardboard

8 Horticultural Waste

9 Glass

10 Textile/Leather

11 Plastics

12 Food waste

13 Others (stones, ceramics & rubber)

Events such as Annual Recycling Weekwere held to encourage and educate citizens

understand the 3R (Reduce, Reuse and Recycle) scheme and thereby raise awareness

on the importance of waste minimization and recycling. There were also schemes like

SPA (Singapore Packaging Agreement) which allowed companies to collaborate with

the government to reduce packaging waste over a 5-year period.

Presently, the only investors in Singapore are statutory boards such as the Singapore

Environment Council and National Environment Agency. While more schemes are


28/31


Potential Investor

23

being introduced to encourage recycling, there are currently no incentive or

obligations for the citizens to recycle.


29/31


Potential Investor

24

6.4 Appendix D

Anaerobic Digestion

Introduction

Anaerobic Digestion is a process that converts biomass into beneficial products using

microorganism in the absence of air. Nearly all biomass can be converted using

Anaerobic Digestion; some examples are food waste, manure and crop residues.

However woody biomass cannot be processed using this method, as the

microorganism is not capable of breaking down lignin in wood.

The process starts with placing biomass in a sealed tank and allows the

microorganism to digest the matters. Some of the major products of the process areBiogas and Digestates.

Biogas can be used as a fuel substitute and can be combust to produce both heat and

electricity. Typically the mixture is comprised of 60% methane and 40% carbon

dioxide and some contaminant gases, but the exact composition depends on the type

of feedstock used.

Digestates are extremely rich in nutrient and thus it can be used as commercial

fertilisers. Some of the benefit of using digestates as fertiliser is that it provides

moisture retention and prevents soil erosion.

Since there are no anaerobic digestion case studies in Singapore, thus in this report the

reference would be based on a Germany waste treatment plant. In this report, the case

study on anaerobic digestion was based on a plant in Germany. Biogas produced from

the anaerobic digestion plant as well as landfill gases from a nearby landfill is being

converted to energy.

The biogas and landfill gases are combusted and the hot flue gas is used to drive gas

engines which will in turn convert the mechanical energy to electrical energy. The

electrical output of the plant is an estimated 1400kW. (Mergias, Malamis & Loizidou,

2007)

From the information gathered from the case study, the plant is designed to generate

kWh/year based on the combustion of the gases. During operation, the


30/31


Potential Investor

25

plant consumes kWh/year, giving it a net electricity production of

kWh/year. (Mergias, Malamis & Loizidou, 2007)


31/31


Potential Investor

6.5 Appendix E

Composting

Introduction

Composting is the natural breakdown (aerobic) of organic material or waste (paper,

cardboard, food & horticulture) into useful composts which are then used as fertilizers.

While there are many types of composting, they are often combined so that it

increases the type of wastes which can be composted. As Anaerobic Digestion is

similar in concept as with Anaerobic Composting and that it has been discussed in the

previous section, it will not be discussed further in this section.

Of interest, Vermicomposting have increasingly been employed as the method for

composting due to its ability to entirely eliminate the need for landfill.

Vermicomposting is the use of worms (black soldier fly larvae or red wrigglers) to

feed on the waste to produce composts which are used as either fertilizers or animal

feed.

The process begins with the conditioning and mechanical sorting and sizing of the

waste so that the composting period can be shortened. The feedstock (waste) would

then be fed through a continuous mechanical bed (in blocks, which aerates and

moisturizes it at specific intervals to ensure a conducive environment for the worms to

work & reproduce. This process takes approximately 1.5 to 2 months before the

compost is ready for use. Figure A1 summarizes the process using integrated cow

farm & vermicomposting plant (Thomas H., 2008)

Figure A1 Summary of Process Flow

sustainable report - final.pdf

Documents