Abstract :
Palm oil constitutes a main agricultural
commodity for the country, therefore the large quantity of
palm oil clinker (POC) produced as a waste at the refineries
is not unexpected. Upon the discovery of the rock-like but
porous POC as being strong and robust enough as substitutes
of aggregates, they have since become popular alternative
materials in road pavement and concrete. However, POC is
also potentially viable in other civil engineering applications
for a second life, and this includes brick-making, soft soil
stabilisation and greywater filtering. (i) Powdered POC was
found to contribute to greater strength gain than cement in
baked clay bricks, promising a cheaper yet more
environmental-friendly building material. (ii) Admixed with
soft clay soil, ground POC was found to effectively dry and
strengthen the originally weak soil through induced
cementation, similar to those achieved by using commercial
binders, like cement and lime. (iii) Crushed POC replacing
conventional sand in a greywater filter for domestic kitchen
sink discharge showed evidence of effective cleansing, where
the filtered water met the requirements of Standard B
effluent suitable for release into public waterways. While the
experimental results strongly suggest the huge potential of
restoring POC to a useful second life in various civil
engineering applications, encompassing the ‘rebirth’ from
cradle-to-grave in a sustainable framework is essential as
assessment and justification for its continued viability. By
putting the materials and methods in a birth-to-death cycle,
from production, application to end-of-life management, the
relevant causes and impact are reviewed and examined. The
inter-related societal, economic and environmental aspects
are then incorporated in a holistic 2-pronged life cycle and
functionality analysis. In short, the sustainability framework
features not only technical soundness of the POC’s
second life, but considers in detail the other consequential
and accompanying factors throughout the ‘second’ life cycle
of POC.
