Liquefaction of sunflower husks for biochar production

Piyo Nontembiso

Supervisor :Prof S.Marx

Co-supervisor Dr I.Chiyanzu

Presentation Outline

• Introduction • Liquefaction: An overview• Objective of the study• Experimental set-up• Methods • Results • Concluding Remarks• References

Introduction

• Increased focus on global warming

• Development of feasible renewable energy source

• Reduction of fossil fuel dependency

• Biomass is the third largest energy resource, following oil and coal

• Clean fuel because it has negligible sulphur and nitrogen content which results in lower sulphur dioxide and nitrogen oxide than conventional fuels

Liquefaction: An overview

Liquefaction:• biomass decomposition reactions carried out in a solvent media at

temperature (200- 400°C),Pressure (5 and 20 MPa), alkaline catalysts• Key principle: products with low oxygen content, high heating content & high H/C ratio• Three products are produced during liquefaction

Biochar • carbon-rich product and a potential solid fuel• Has numerous uses such as:• can be combusted/gasified for heat and power• activated for adsorption application • applied as a soil amendment• and carbon sequestration agent

Objective of the study

• To investigate the effect of solvents, reaction temperature and reaction atmosphere on biochar production during liquefaction of sunflower husks.

Experimental setup

Methods

Input variables:

• Liquefaction temperature 240-320 °C• Liquefaction reaction atmosphere: CO₂ and N₂• Reaction solvents :water, methanol, ethanol, iso-propanol

and n-butanol

Analytical techniques used• Proximate analysis• X-ray diffraction• Fourier Transformed Infrared• Scanning electron microscope • Brunauer-Emmet-Teller • Elemental analysis

Results

Figure1: Effect of solvent on biochar yields under different Figure 2: Effect of temperature on biochar yields in ( CO₂, N₂) at atmospheres ( CO₂ and N₂) at 280°C different reaction atmospheres

Results continues ……………….

Table 1: Elemental analysis of biochar samples under (N₂ and CO₂ atmosphere)

Figure 3: FT-IR spectra of sunflower husks and its biochar

obtained at different liquefaction temperatures in CO₂ atmosphere ( Raw biomass, 260⁰C,

280⁰C, 300⁰C).

Concluding Remarks

• We have demonstrated that biochar properties and yields are a function of production process conditions

• The biochar yields were influenced in this order > by temperature > type of the solvent > reaction atmosphere.

• The heating value of the biochar is high (26.76 MJ/kg) and comparable to that of conventional fuel such as lignite (25.0 MJ/kg)

• This increases its potential to be used as fuel

• Sunflower husks is a promising feedstock in the production of useful products such as biochar through liquefaction

• Thermochemical conversion of sunflower into solid fuel like biochar may play an important role in solving the growing energy demands

References

• Bridgwater, A.V. & Maniatis, K. 2004. The production of biofuels by the thermochemical processing of biomass, in molecular to global photosynthesis. In: Archer M.D. & Barber, J. eds. London UK: IC Press, pp. 521-612.

• Brown, R.C. 2011. Thermochemical processing of biomass: Conversion into fuels, Chemicals and Powder, 1st ed., John Wiley & Sons, Ltd.

• Demirbas, A. 2009. Current activities and future developments. Energy Conversion and Management, 50: 2782-2801.

• Demirbas, A. 2001. A Biomass resource facilities and biomass conversion processing for fuels and chemicals. Energy Conversion and Management, 42:1335-78

• Horio, M. 2009. Development of biomass charcoal combustion heater for household utilization. Industrial and Engineering Chemistry Research, 48(1): 361-372.

Thank you