| dc.description.abstract | Ocean Thermal Energy Conversion (OTEC) Power Plant used working fluids
(ammonia) which were evaporated by warm sea surface water to produce effective
pressure for electric generator. Cold sea water pipe (CSWP) was used to transport
cold sea water from sea bed to the sea surface, (for 2 MW generators, require
minimum 500 m depth, and 4 m diameter to reach 5oC cold sea water temperature),
to condensate and circulate the ammonia vapour to produce sustainable and
environment friendly electricity. Glassfibre-high density polyethylene (GF-HDPE)
composites have been recommended as alternative materials for the CSWP
installation. However, delicate manufacture should be carried out to achieve
compatibility and finely distribution of the fiberglass, whereas the composite
materials should be able to withstand against contiuous loads from sea wave and
currents as well as hydrostatic pressure in deep sea environment. Palm oil mill boiler
ash (POMBA) contains silica upto 17% and can be utilized as fillers and
reinforcements for polymer composites. Addition of adhesion promotor (carrier) of
maleated polypropylene (PPgMA), improve distribution, compatibility, and
adhesion of the POMBA fillers, without formation of micropores (voids), which
susceptible to crack initiation under external loads in the HDPE composites. In this
works, POMBA samples were treated in acid solution, in which 32.78% of the
mineral contents was washed leaving chemical composition of the ABPKS filler: Si
(IV), Ti (VI), C (IV) and Oxygen. Mean/Median particle size of the treated- POMBA
were smaller than those of before washing, with morphology of spherical shape
without minerals coating. Then, composite materials based on HDPE with POMBA
as filler in the presence of PPgMA as adhesion promiter were prepared using Twin
Screw Extruder at various temperaturs (150o -180oC), and rotation speeds (60-100
rpm). It was found that the presence of PPgMA as compatibiliser, improved
adhesion/interaction which inturn increased mechanical strength of the composite
materials. Here, optimum composition of HDPE/PPgMA/POMBA30 composite
was chosen, i.e. when POMBA loading was 30 php (per hundred polymers), and
weight ratio HDPE/PPgMA: 9/1. The presence of POMBA fillers function as:
reinforcements, thermal stabilizers, crystalinity reducers of the HDPE composites.
Simulation of von Mises drag force due to constant wave and sea currents based-on
those of in Makasar Strait in Sulawesi Selatan, using HDPE/PPgMA/POMBA
composite as construction material found that structure of cold sea water pipe
(CSWP) were safe if the thickness ≥ 14 cm, whereas for fluctuated wave and sea
current the safe thickness ≥ 24 cm. | en_US |
