Taiwan-Malaysia Workshop on Clean Water and Sustainable Energy, to be held at Universiti Teknologi Malaysia, Johor Bahru, on 5-6 August 2019

1. Carbon Dioxide Torrefaction of Anaerobically
Digested Palm Oil Mill Effluent (POME) Sludge
for Clean Energy Production
By
Dr. Bemgba B. Nyakuma

2. Co-Authors
Tuan Amran T. Abdullah (Ph.D),
Olagoke Oladokun (Ph.D),
Yakubu A. Dodo (Ph.D),
Terstegha J-P. Ivase (MSc),
Jemilatu O. Audu (MSc),
Edo O. Ojoko (MSc),
Samuel Moveh (MSc).
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3. Outline of Presentation
Introduction
Experimental
Results & Discussion
Conclusion
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4. Introduction
 Growing global demand for crude palm oil
(CPO)
Cultivation of (Elaeis guinnensis Jacq.)
 Over 95 million tonnes of fresh fruit
bunches (FFB) harvested annually.
 Malaysia >> 20 million tonnes of crude
palm oil (CPO) annually.
 Oil yield (20-23%), process generates vast
oil palm wastes (OPW) Solid & Liquid
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https://go.nature.com/339UWih

5.  Liquid wastes palm oil mill
effluent(POME).
 1.0 ton of crude palm oil (CPO)
produced, 2.5 tons of POME is
generated with 1100 kg of CO2 eq.
 Over 45 million tons of POME
generated annually in Malaysia.
 Over 400 Oil Palm Mills (OPMs) in
Malaysia.
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6. What is POME?
 POME >> wastewater generated from
processing oil palm fresh fruit bunches.
 Thick brown coloured colloidal mixture of
water, oil and suspended solids.
 Non toxic but has high BOD, COD, N & P. Acidic
(pH = 4.5) >> organic acids.
 Major source of water pollution in Malaysia
 Requires treatment before discharge into
receiving water bodies or the environment.
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https://bit.ly/335O7hI

7.  POME Treatment >> biological process is
based on anaerobic & aerobic ponding
system.
~ 85% of palm oil mills have treated raw
POME using biological treatment.
 Biological treatment >> series of pond
systems >> anaerobic, facultative &
aerobic pond systems.
 Four types of POME Treatment: Waste
stabilization ponds, Activated sludge,
Anaerobic digester & Land application.
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8. Introduction
 These strategies emits significant quantities of other
greenhouse gases (GHG) viz CO2, NOx & SOx resulting in
burden on the environment.
 Anaerobic digestion (AD) is considered for valorising
POME, process generates secondary wastes termed
Anaerobically Digested POME Sludge (ADPS).
 High organic matter content, ADPS is a potential biomass
feedstock for thermochemical conversion & energy
recovery to improve its biofuel properties.
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9. Introduction
 Torrefaction is low temperature pre-treatment process for
converting low value feedstock into high heating value fuels.
 200 - 300 °C, 1 Atm, Low heating value < 50 °C/min,
 Inert or oxidizing gas N2, O2, Air,
 Low moisture, hydrophobicity, grindability, calorific value.
 Has high moisture content (>60%), low gravimetric density, &
low calorific value.
 Anaerobically Digested POME Sludge (ADPS) carbon
feedstock that requires pretreatment & thermal conversion.
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10. Objectives of the Study10
 To characterize the biomass fuel properties of
Anaerobically Digested POME Sludge (ADPS).
 To examine the CO2 torrefaction of ADPS through
thermogravimetric analysis (TGA).
 To examine the bioenergy potential of ADPS through
torrefaction product analysis.

11. Experimental
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Anaerobically
Digested POME
Sludge (ADPS)
Biomass Fuel
Properties of
ADPS
CO2
Torrefaction of
ADPS
Bioenergy
Potential of
Torrefied ADPS
Proximate Analysis
(Moisture Content
Volatiles, Ash, Fixed
carbon, using
ASTM Standards
D3173-3175
Calorific Value
Analysis to determine
higher heating value
(HHV) using ASTM
D2015
Torrefaction by heating
20 mg of ADPS in TGA
from 30 to 240-300 °C;
heating rate of 20 °C/
min under carbon
dioxide (CO2), flow rate
= 50 mL/min for 30
minutes
Analysis of TGA/DTG
plots using Shimadzu
TG-50 Thermal
Analyser
Computation of the
Mass & Energy
yields, Heating value
(HHV), Energy
density, & Severity
Factor

12. Experimental - Methods
 Torrefaction performance was evaluated by;
 Mass yield (MY), energy yield (EY), energy density (DE), & higher
heating value (HHV) >> calculated from Eqs 1.1 to 1.4.
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13. Results & Discussion13
Property Symbol ADPS Lignite Coal EFB
Moisture MC 5.18 4.75 7.78
Volatile Matter VM 55.25 69.52 75.19
Ash Content Ash 11.05 2.43 5.80
Fixed Carbon FC 28.52 23.30 11.24
Heating Value HHV MJ/kg 15.25 19.40 17.57
To characterize the biomass fuel properties of
Anaerobically Digested POME Sludge (ADPS).

14. Results &
Discussion14
To examine the CO2 torrefaction of ADPS through
thermogravimetric analysis (TGA).
Fig 1: TG-Time Plots for CO2 Torrefaction of
ADPS
Fig 2: DTG-Time Plots for CO2 Torrefaction of
ADPS

15. Results &
Discussion
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Fig 3: TG-Temperature Plots for CO2
Torrefaction of ADPS
Fig 4: DTG-Temperature Plots for CO2
Torrefaction of ADPS

16. Results & Discussion16
To examine the bioenergy potential of ADPS
through torrefaction product analysis.
Fig 5: Mass, Energy, Energy Density for CO2
Torrefaction of ADPS
Fig 6: Heating value, Mass Loss, & Severity
Factor for CO2 Torrefaction of ADPS

17. Conclusions17
 Results showed that the mass yield (MY, %) decreased from 85.2
to 73.34% with increasing mass loss (ML, 14.79 to 26.7%) &
torrefaction temperature (TT, °C) from 240-300 °C.
 Higher heating value (HHV) increased significantly 15.25 to the
range 21.2 to 22.34 MJ/kg (or 39-45%) and Severity factor during
ADPS CO2 torrefaction.
 Findings showed that CO2 torrefaction could substantially
improve the biofuel properties of ADPS for future clean energy
applications.

18. Acknowledgments
The financial support of the Ministry of Education (MoE)
Malaysia and Universiti Teknologi Malaysia for the GUP Tier 1
Grant (VOT No: 20H52) is gratefully acknowledged. Many
thanks also accrue to the Institute of Future Energy (UTM) and
School of Chemical & Energy Engineering UTM (Skudai
campus) for the material and technical support.
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19. References19
 Kamyab, H., Chelliapan, S., Din, M.F.M., Rezania, S., Khademi, T. and Kumar, A., 2018.
Palm Oil Mill Effluent as an Environmental Pollutant. Palm Oil, p.13.
 Kamyab H, Din MFM, Ghoshal SK, Lee CT, Keyvanfar A, Bavafa AA, et al. Chlorella
pyrenoidosa mediated lipid production using Malaysian agricultural wastewater: Effects of
photon and carbon. Waste and Biomass Valorization. 2016;7(4):779-788.
 Nyakuma, B.B., Ahmad, A., Johari, A., Abdullah, T.A.T., Oladokun, O., Al-Shatri, A.H., Ripin,
A. and Alir, A., 2019. Preliminary torrefaction of oil palm empty fruit bunch pellets. In E3S
Web of Conferences (Vol. 90, p. 01014). EDP Sciences.
 Nyakuma, B.B., 2019. Burning Characteristics And Fuel Properties Of Obomkpa, Ihioma, And
Ogboligbo Lignite Coals From Nigeria. Petroleum & Coal, 61(1).
 Yacob S, Shirai Y, Hassan MA, Wakisaka M, Subash S. Start-up operation of semi-
commercial closed anaerobic digester for palm oil mill efuent treatment. Process
Biochemistry. 2006;41(4):962-964.