Abstract:
Palm oil processing generates enormous volume of waste, which can be used as
a feedstock in thermal processing. Subsequently, these can be valuable in the
production of activated carbon (AC) and soil amelioration. The production of AC
often results in secondary contamination through activating agents. This prompts
the necessity for a non-toxic activating agent for high quality production of high
adsorptive AC. Therefore this research aims to assess and determine the
optimum route for efficient utilisation of biowaste from thermal conversion process
of palm oil residues in producing activated carbon and soil amelioration by
evaluating the impact of the selected utilisation techniques.
In the production process, energy demand and process duration have influence
on the efficiency of AC; therefore, an appropriate design configurations and
parameter selection are required to achieve an anticipated yield. AC was
produced by microwave and conventional techniques through pyrolysis. The
feedstock was also used in combustion and the thermal residues were applied in
agricultural soil and crop yield relative to application rate was assessed on
Habanero chili pepper. Therefore, the requisite to quantify the processes, which
include appropriate assessment of the technology and economic performance.
The accomplishment of the project overall aim was dependent on the design of a
microwave system for efficient biomass pyrolysis. The process also evaluated the
microwave interaction with reactors implemented to produce AC from mixed oil
palm waste, using Trona ore as an activating agent. The AC was analysed to
determine the effectiveness of Trona ore for activation using Fourier infrared
spectrometry, Brunauer-Emmett-Teller (BET) analyser and scanning electron
microscope. The oil palm waste ash was applied to the soil. The optimum
outcome of the microwave assisted technique for combine palm waste (CPW)
was obtained at 600 W, BET surface area (SBET) is 980 m²/g compared to 920
m²/g from a conventional technique; total volume (Vtotal) 0.865 cm³/g; mean pore
diameter 2.2 nm and AC yield is 42%. Therefore, this study additionally identifies
the need for an even distribution of electromagnetic waves within the reactor
during activation to ensure uniformity of AC. It also proposes that the design of a
composite reactor for an industrial production of AC is necessary to enable
heterogeneous waste stream of the process. For ash application, the
physiological development and crop yield were measured. The combine
maximum yield for both sites were 49 t/ha/first season and 71.8 t/ha/second
season, occurred at 8 t/ha treatment plot against the control plot with 1.3 t/ha/first
season and 0.7 t/ha/second season. The interaction between oil palm waste ash
and soil, improved agronomic efficiency of Habanero chilli pepper by 66-69% and
Scoville value by 3.52%. These utilisation routes (AC production and ash to soil)
were further integrated for economic and technological benefits using Aspen plus
Economy. The processes have 16-17% return on investment for the 8-9 year
payback period. This study therefore concluded that thermal residues of oil palm
waste are useful in the production of high quality AC and also has rich effect on
agricultural soil.