The Current State Of

Development Of Biogas

In Singapore

Presented by

Wang Jing-Yuan

Director, R3C 13 June 2013 @ KL, Malaysia

Biogas Projects in Singapore

• Waste is not waste, but misplaced resource

• Food waste to biogas (IUT Global)

• NTU’s two phase AD system

• Decentralized waste management

• Chew’s chicken dung conversion

R3C

Residues and Resource Reclamation Centre

• R3C was established on 1 May 2009 by EDB/EWI/ NTU and was officially launched on 5

Oct 2009.

• The main objective is to conduct cutting edge research and strengthen Singapore’s

environmental industry’s capability in the area of waste resource management.

• R3C works closely with government agencies and industry

• R3C acts as an R3 resource and technology transfer centre.

• R3C provides education and training for R3 professionals.

2

R3C Researchers

3 Management + 2 Admin / Lab support + 9 RF + 21 RA + 17 PhD students + 13 Faculty Affiliates (65+)

Director

A/Prof Wang Jing-Yuan (NTU)

Advisors to Director

Prof Rainer Stegmann (TUHH)

A/Prof (Adj) Cheong Hock Lai

Waste to Materials

NEWRI

Waste to Energy Contaminated Site

Remediation

3

6

Recycling Food Waste by IUT GLOBAL

7

Food waste recycling into biogas and compost by IUT Global

Ammonia

detector

Feeding and shredding Aeration and sedimentation Submerged bio-filter

Acidogenesis Equalization Methanogenesis

Discharge High Low

The demo-plant for co-

generation of hydrogen and

methane with a capacity of

3 tonnes of food waste per

day

R3 Research Activities in NTU

Hydrogen Methane

Residue as fertilizer

Food waste

Reuse

NTU unleashes energy hidden in food waste

Peristaltic

pumps

Gas Meter

Acidogenic

Reactor (Ra)

Methanogenic

Reactor (Rm)

Effluent from

Rm

Biogas Production

Hybrid Anaerobic Solid-Liquid (HASL) System

Effects of lipid on HASL performance

Experimental setup

HASL Bioreactor vs Conventional Anaerobic Digesters

The mini pilot-scale HASL system

Food Waste Collection

Clogging Issues

Issues of Current Waste Management

• The centralized waste management approach is expensive in

terms of consumption of water, energy, and infrastructure

investment

• Liquid: activated sludge process (water flushing + aeration +

nitrification and de-nitrification + sludge dewatering + …)

• Solid: collection and transportation (energy consuming) +

emissions from incineration and landfilling (land

contamination)

• Subsequent residues disposal (sludge, incineration ash, etc)

• Separation of material streams

Separate collection of brown, yellow, and grey water

Recovery and reuse of nutrients, purified water, and

useful residues (e.g., compost)

Minimisation of waste through all those Rs (reduce,

reuse, recycle, recover, rethink, repair, restore,

remediate, and many other Rs)

• Conversion of recoverd materials to useful resources

Biogas to energy

Residues to compost or fertizer

Others

The Decentralized Waste Management

Concepts

Decentralized urban resource recovery (DUR2) system development

No-mix vacuum

toilet

Urine for nutrients

recovery through

struvite precipitation

and air stripping

Co-digestion of food

waste and brown

water

Heat

and

Energy

The integrated system currently is under design

Cost projection: EOM (1.9M) + OOE (830K)

Example: Decentralized Vacuum System

Kitchen basin Separation toilet I + II

Garbage grinder

Kitchen waste

Storage tank

Yellow water

Storage tank

Brown water

Storage tank

Kitchen waste

Sewer system

Separation toilet

+ Storage tank

Wash basin

+ Garbage grinder

Separation of Brown Water, Yellow Water,

and Kitchen Waste

Communities as Renewable Resource Recovery Centers (CRP/NRF)

R3C position going Forward (Towards Zero Waste)

Work together with industrial partners:

• Design fine-tuning

• Prototype manufacturing

• Demonstration construction

• Test bedding

No-mix vacuum toilet development

7

No-mix toilet demonstration @ NTU

People’s acceptance: • A logbook is prepared for users’

comments. • Questionnaire will be used for further

assessment.

No-mix toilet + Vacuum system

Principles:

Low water consumption

Pressure applied

1L water consumption

Pipe diameter 32

to 40mm

Closed

system

Penumatic Operated

Flush Button

flap valve

Vacuum Operated

Closing Valve

Urine

by

gravity

No-Mix Toilet + Vacuum System

Photographs of typical configurations of two-chamber MFC (A) and MEC (B)

Gas collector

Anode: CH3COO- + 3H2O → CO2 + HCO3

- + 8H

+ + 8e

- (-0.29V)

Cathode: 2O2 + 8H+

+ 8e- → 4H2O (0.81V)

Overall: CH3COO- + 2O2 → CO2 + HCO3

- + H2O (1.10V)

Cell voltage is positive, implying that electricity can be produced

from the MFC.

Anode: CH3COO- + 3H2O → CO2 + HCO3

- + 8H

+ + 8e

- (-0.29V)

Cathode: 8H+

+ 8e- → 4H2 (-0.41V)

Overall: CH3COO- + 3H2O → CO2 + HCO3

- + 4H2 (-0.12V)

Cell voltage is negative and hence electricity needs to be invested

to drive the MEC to produce H2.

A B

No-Mix Vacuum Toilet

Diverted urine

Vacuum evacuation

Local Characteristics Prototype

User Feedbacks Trial Sites

Lab Demo Technology

Disclosure

Further Improvement

Industrial Partners

Commercialize with

Industry Partners

Test bedding 1 @ NTU campus Blk N1 level 2 Test bedding 2 @ Jurong Lake Park

No-Mix + Vacuum

Research Activities Completed

Next Phase

Data Collection and Analysis

Disclosures and

Patents

(US Provisional Patent Application No. 61/663,978)

Anaerobic Co-digestion of Brown Water and Food Waste

Hybrid

30L Digesters 5L Digesters

5-L digester 30-L digester

Two-Phase CSTR SBR Two-Phase SBR Hybrid

TS Removal (%) 60 58 79 59

VS Removal (%) 67 66 89 73

Total COD Removal (%) 61 67 89 76

Soluble COD Removal (%) 77 92 91 92

Increase in tVFA levels 5 times - 5 times -

Biogas Yield (m3/kg VSadded) 0.59 0.51 0.5-0.8

2-phase CSTR

Single stage CSTR

SBR 2-phase SBR

Anaerobic

digestion

CH4+CO2 Solid oxide fuel cell (SOFC)

Proton exchange membrane fuel cell (PEMFC)

Microbial electrolysis cell (MEC)

H2

Liquid effluent

H2

• The sulfur tolerance of Ni/Gd2O3-CeO2 (Ni/GDC) anodes under SOFC operation was promoted by

impregnated palladium nanoparticles

• To improve the SOFC anode tolerance against carbon coking, a new anode SrMoO3-YSZ was

developed as the Ni free anode

Electricity

• New composite membrane and alternative catalyst have been developed for MEC

• Technology disclosure “A Method to Synthesize High Surface Area WC Nanorod for Catalysis/Electrocatalysis Applications,” filed on 13 March 2012 (US Provisional Patent

Application No. 61/610,240)

Decentralized Power Source : Electricity generation Converting waste to power MEC + SOFC + PEMFC systems

Engineering micro-organisms & electrode materials for high-electricity-output Microbial Fuel

Cells

e

Electron transfer path

Electron

Cytochrome protein (OmcA)

3D Graphene/PANI electrode

Lactate

CO2

e

e

Re

e

S. oneidensis MR-1 cell

PANI

Graphene

Flavin

eRe

e

Ox

Re Reductive

Ox Oxidative

• Engineering a graphene-polyaniline-based highly conductive 3-dimensional (3D) composite

electrode and bacteria, which generates as high as 600 mW/m2

electricity output. Thus,

significant amount of electricity can be harvested from wastewater • Next step, scale-up the electrode fabrication process to enable MFCs adoption into

wastewater treatment industry

• Alternative charging/discharging of an array of MFCs to generate higher voltage

(e.g., 3-5 V) • Thus voltage can be used to heavy metal (e.g., Pb) bioremediation in soil

MFC1

MFC1

MFC1

MFC1

MFC1

+ -

+ -

+ -

+

+

-

-

high-capacity

capacitor

So

il co

nta

min

ate

d b

y P

b

Cost projection: EOM (600K) + OOE (90K)

Wastewater Treatment Plant as an Urban Eco Power Station … from power consuming to self-sustaining

(NEA, PUB, Keppel)

Prof Ng Wun Jern (PI) Programme B:

PROCESS ENHANCEMENT TARGETS: 1.Biogas production - 30% above 0.8-1L/g VM destroyed; 2.Co-digestion with O&G; 3.Reduce solid mass - 70% solids removal; 4.Improve sludge biological stability & dewaterability; 5.Reduce sludge disposal cost - 20%.

Research Capabilities Developed and Next Steps

Research achievement: Enhanced volatile solids

destruction (57.4% VS reduction) was achieved in

mesophilic 2-stage system compared to the 30-

35% VS reduction in state-of-the-art plants.

Technology disclosure:“A Method for in-situ

thermal-alkaline treatment to enhance

anaerobic solids degradation and biogas

generation,” filed on Oct. 18 2012 (TD/179/12; US

Provisional Patent Application No. 61/715,592)

Commercialization: The capability already developed

considered for possible application by Keppel

at full scale to reduce sludge incineration and ash

disposal requirement, and also produce more

biogas and thus shift wastewater treatment closer

to being energy positive.

Further Research: 1) A novel 2-stage anaerobic

system for enhanced bio-solids destruction and

biogas production; 2) A novel 3-stage anaerobic

system for rapid solids destruction being discussed

as a spinoff from 2nd technology disclosure.

Enhanced sludge digestion laboratory system

Enhanced sludge digestion pilot system

Cost projection: EOM (95K) + OOE (470K)

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Biogas Plant Project

for AVA Food Fund II

Presented by

Chew Chee Bin

Chew’s Agriculture Pte Ltd

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Chew’s Company Profile

1. Chew’s is a leading farm in Singapore that

produces designer and other quality eggs

in a controlled and safe environment for an

established customer base.

2. Average daily egg production: 360,000

3. Average daily output of chicken dung: 50 tons.

4. Current method of chicken dung disposal:

-Conventional and speedy fermented solid

fertilizer for vegetable farming In Singapore.

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Problem Arise From Chicken Dung

1. There is very low demand on solid fertilizer in

Singapore and export to nearby country is a

challenge.

2. Conventional and speedy fermented solid

fertilizer require large land area, labor intensive,

high electricity consumption and environment

problem such as like odors.

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Solution by Using Biogas Plant

-Biological process in anaerobic environment

(Oxygen free and closed system).

-Eliminates the odor problem.

•Less area and manpower is required.

•Generates electricity, heat, Bio-solid fertilizer

and liquid fertilizer in one process.

•Bio-solid fertilizer is about 15% of total weight of

fresh chicken dung.

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Solution by Using Biogas Plant

• Suitable to use vertical cage with auto dung

collection system together with conveyer in

feed to biogas plant, less manpower and

increase productivity.

• Technician will need to operate and do the

system maintenance.

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Biogas Plant Working Principle

-Fresh chicken dung + H20 = C5H7NO2+HCO3

-Further conversion of dissolved compounds

like organic acids and alcohols by bacteria

(C5H7NO2, HCO3) into gases - CH4, CO2,

NH4.

-CH4 will convert to electricity and heat.

-By-products are bio-solid and liquid fertilizer.

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BIOGAS PLANT…TANK SYSTEM

BioFlow Biogas Generation System

(Completed Plant)

Belt Filter Press For Sludge Dewatering and Solid-Liquid

Separate of Digestate

BioFlow Effluent Treatment Plant

Capstone MicroTurbine® Energy Solutions

CR200/CR1000 (Type A) designed for

methane level of 24% to 59%, and H2S level

of up to 5,000 ppmV. Biogas compressor

(which remove moisture and compress

biogas to 80 psig) designed for H2S level of

4,000 ppmV.

No H2S scrubbing needed, reducing

capital and operating costs.

Turbine with air bearing design with no

lubrication oil. No coolant/jacket water.

High combustion temperature fully

‘destruct’ the H2S (and ammonia).

Operates on ‘grid-connect’ and ‘load

following’ based on farm load.

A unit of CR200 can be maintained while

the other CR200 running, providing

redundancy.

Exhaust flue gas (300C) available for

WHR.

High availability and relaibility.

79,999 operating hours ‘comprehensive’

maintenance covering scheduled and

unscheduled, parts and labor.

Philippines Reference Site

Capstone MicroTurbine® CR800 @ Piggery Farm

Modularized Package CR800 Engineered Biogas Delivery Skid

Clean Emission

Engineered Exhaust Duct

Clean Cycle® CC125 Energy Solutions

Waste heat generator converts heat

energy into electrical power using

Organic Rankine Cycle (ORC)

technology.

Exhaust flue gas from 3 units of

CR200 (direct WHR in external

evaporator) support 1 unit of CC125

operation.

High speed generator (magnetic

bearings) with no gear box and no

lubrication oil improve efficiency and

provide high reliability.

Grid-friendly power electronics.

Modular design.

79,999 operating hours

‘comprehensive’ maintenance covering

scheduled and unscheduled, parts and

labor.

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SUMMARY

-To invest 4.2 million to build a 40 tons chicken dung

biogas plant.

-To enhance Singapore food security by increase egg

production from 360,000 to about 500,000 per day by

year 2013.

-To reduce pollution caused by chicken waste.

-To improve the productivity on land usage and

manpower ,i.e.: less dependent on unskillful

manpower .

- To integrate with future vegetable & food fish farming.

Summary

• Urban Biomass to Energy

• Food Waste to Biogas (IUT Global)

• NTU’s Two Phase AD System

• Decentralized Waste management

• Chew’s Chicken Dung Conversion

R3C website: http://www.ntu.edu.sg/r3c

Thank You

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