Non-Isothermal Kinetic Analysis of Oil Palm Empty Fruit Bunch Pellets by Thermogravimetric Analysis

- Bemgba Bevan Nyakuma -

18th Conference of Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction (PRES Conference)

PRES’15 conference, 22-27 Aug 2015, Kuching, Malaysia.

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Arshad Ahmad, Anwar Johari, Tuan A. T. Abdullah, Olagoke Oladokun, Dodo Yakubu Aminu

Co-authors

• Introduction

• Experimental

• Results

• Conclusion

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Contents

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Introduction

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• Malaysia >> 2nd largest producer & exporter of Palm Oil with >> 400 palm oils mills and 4.5 million hectares of Oil Palm (Elaeis guineensis).

• Palm oil production generates large quantities of Liquid (POME) & Solid (Lignocellulosic) waste

• Solid Waste >> Empty Fruit Bunch (OPEFB), Palm Fronds (OPF), Palm Kernel (OPK), Palm Fibre (OPMF).

Introduction

6Source: http://www.slideshare.net/yongkangbirdnest/oil-palm-industry-in-malaysia

Introduction

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Fresh Oil Palm Fruit Bunches

Pelletized Oil Palm Empty Fruit Bunches (OPEFB)

Oil Palm Empty fruit Bunches (OPEFB)

Introduction

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Solution

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• Current conversion technologies – open air burning, incineration, land filling, boiler fuel & prod. steam

• inefficient, outdated, hazardous, unsustainable

• Valorization of OPW into clean energy fuels, power generation challenges of OPW accumulation.

• Biomass utilization price volatility, dwindling reserves & environmental pollution associated with fossil fuels

Solution

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Challenges

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• Biomass properties - high moisture, inhomogeneous sized, high alkali content, and low energy density fuels

• Pre-treatment and Conditioning• Drying, Densification, Pelletization, Mechanical

Fractionation, Hydrolysis & Torrefaction, Carbonization.

• To improve feedstock, thermochemical / physicochemical properties, supply chain, logistics and storage

Challenges

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Way Forward

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• Fossil fuels clean bioenergy fuels transition >> knowledge of thermal degradation behaviour & decomposition kinetics.

• Mathematical models developed by Flynn-Wall (Flynn and Wall, 1966) and Ozawa (Ozawa, 1965)

• Analytical techniques >> thermogravimetric analysis (TGA) used to investigate the thermal decomposition kinetics of biomass.

• Vital feasibility, design and scaling up biomass thermal conversion equipment & Optimizing yield & composition of products of thermal conversion.

Way Forward

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Study Objective

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To examine the thermal degradation behaviour of oil palm empty fruit bunches (OPEFB) pellets using TGA.

To determine the decomposition kinetics of the OPEFB pellets using the Flynn-Wall-Ozawa (FWO) kinetic model.

Way Forward

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Experimental

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• Biomass Procurement >>• Oil palm empty fruit bunches (OPEFB) pellets Oil Palm Mill in

Johor, Malaysia.

• Biomass Characterization >> • Elemental composition & Proximate analysis • Bomb Calorimetry Analysis

• Thermal Analysis >> • Thermogravimetric (TG) analyser (NetzschTM 209 F3), • Nitrogen flow rate of 50 mL/min. • 10 mg heated from 30 to 1000 °C • Three (3) heating rates, β = 5, 10, 20 °C/min.

• Kinetic Analysis >> • Flynn Wall Ozawa (FWO) model applied TG data to obtain;

• Activation energy, Ea, & Frequency factor, A at different conversions, α.

Experimental

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Experimental

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Results

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Results > Biomass Characterization

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Figure 1: TG curves of Oil Palm Empty Fruit Bunch (OPEFB) pellets.

Results > Thermal Analysis

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Results > Thermal Analysis

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A – Drying ( < 100 °C); B – Active Pyrolysis (200-500 °C); C – Passive Pyrolysis ( > 500 °C)

Figure 2: DTG curves of Oil Palm Empty Fruit Bunch (OPEFB) pellets

Results > Thermal Analysis

A B C

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Kinetic plots for OPEFB pellets using Flynn-Wall-Ozawa (FWO) model

Flynn-Wall-Ozawa (FWO) model >> In β against 1/T

Results > Kinetic Analysis

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Ea - Activation energy >> Slope – 1.052Ea/R where R = 8.314 J/mol K; A - Frequency factor >> In[AR/Ea)].

Results > Kinetic Analysis

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• Average Ea OPEFB pellets (160.21 kJ/mol) << Cornstalk (206.40 kJ/mol), Sawdust (232.60 kJ/mol), Oak (236.20 kJ/mol).

• Ea is the minimum energy requirement for reactants for chemical reaction, high Ea values = Slower reactions.

• Lower Ea values for OPEFB pellets emphasizes its suitability as a feedstock for thermal conversion processes.

Results > Kinetic Analysis

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Conclusion

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• Pyrolysis kinetics of OPEFB pellets pyrolysis was investigated using TGA.

• The results indicate pyrolysis occurs 3 stages; drying, active pyrolysis & passive pyrolysis.

• Flynn-Wall-Ozawa (FWO) model was applied to deduce the kinetic parameters; Activation energy, Ea, & Frequency factor A.

• Average Ea & A values for OPEFB pellets >> 160.20 kJ/mol and 1.38 x 1024 min-1, respectively.

• Thermo-chemical and Pysico-chemical properties indicate OPEFB pellets is a potentially suitable feedstock for biomass conversion.

Conclusion

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Acknowledgement

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The authors acknowledge the Ministry of Education (MOE) Malaysia for the Long Research Grant Scheme (LRGS) VOT: 4L817.

The authors are grateful to S. L. Wong, and Muhamad Faizal B. A. Halim of Universiti Teknologi MARA, Shah Alam for the TG

measurements.

Acknowledgement

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Terima kasih(Thank you)