Modifikasi Batu Kapur Madura Dan Aktivitas Katalitiknya Pada Reaksi Transesterifikasi Minyak Nabati Menjadi Biodiesel

Widiarti, Nuni (2021) Modifikasi Batu Kapur Madura Dan Aktivitas Katalitiknya Pada Reaksi Transesterifikasi Minyak Nabati Menjadi Biodiesel. Doctoral thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Batu kapur (CaMg(CO3)2) Madura, Indonesia telah dimodifikasi dengan berbagai surfaktan antara lain cetyltrimethylammonium bromide (CTAB), Polyethylene glycol (PEG), dan rarasaponin untuk memperoleh CaO/MgO. Tujuan dari penelitian ini adalah menghasilkan material katalis CaO/MgO dengan luas permukaan yang tinggi dan ukuran partikel yang lebih kecil melalui metode kalsinasi-hidrasi-dehidrasi (CHD). Dekomposisi termal dolomit CaMg(CO3)2 dilakukan pada 900 °C selama 3 jam. Proses CHD dengan berbagai surfaktan (CTAB, PEG, dan rarasaponin) dilakukan dengan metode sonikasi dan hidrotermal. Modifikasi NiO dengan CaO/MgO-P untuk meningkatkan stabilitas katalis dilakukan dengan impregnasi. Hasil penelitian menunjukkan bahwa PEG bertindak sebagai surfaktan terbaik menghasilkan katalis CaO/MgO-P dengan ukuran partikel ̴ 377 nm, luas area 39 m2/g, volume pori (0,0322 m3/g) dan kebasaan (7,8 mmol/g). Kondisi optimal reaksi transesterifikasi minyak kelapa dengan CaO/MgO-P dicapai pada: rasio metanol: minyak (1: 9), beban katalis (5%), dan suhu reaksi (125 °C) menghasilkan biodiesel sebesar 81,76%. Keberadaan NiO pada katalis 5% NiO/CaO/MgO-P memberikan sisi asam dan basa katalis yang dapat meningkatkan hasil biodiesel hingga 90%. Kinetika reaksi transesterifikasi dengan katalis NiO/CaO/MgO merupakan reaksi pseudo orde satu dengan nilai A= 35,07 min-1 dan nilai Ea = 24,47 kJ/mol. Parameter termodinamika seperti ΔH, ΔS dan ΔG diperkirakan masing-masing 21,31 kJ/mol, -0,226 kJ/mol dan 111,259 kJ/mol. Sifat biodiesel yang meliputi kinematik, densitas, titik nyala, bilangan asam, dan residu karbon diperoleh berturut-turut 1,93 mm2 /s, 0,86 g/cm3, 137 °C, 0,27 mg KOH /g, dan 0,22%. Uji reusabilitas katalis NiO/CaO/MgO menunjukkan bahwa katalis stabil selama 2 siklus dengan yield biodiesel sebesar 89,00 % pada siklus pertama dan menurun drastis menjadi 51,95 % pada siklus ke empat.
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Limestone (CaMg(CO3)2) from Madura, Indonesia has been modified with various
surfactan including cetyltrimethylammonium bromide (CTAB), Polyethylene
glycol (PEG), and rarasaponin to obtain a CaO/MgO. The aim of the research is to
produce a high surface area and smaller size particle of transesterification catalyst
material via the calcination-hydration-dehydration (CHD) method. The thermal
decomposition of dolomite CaMg(CO3)2 was conducted at 900 °C. The CHD
treatment with various surfactant (CTAB, PEG, and rarasaponin) were proceed by
sonication and hydrothermal method. The catalytic performance was carried out on
coconut oil transesterification reaction. The modification NiO with the CaO/MgO
to improve activity dan stability of the catalyst were proceed by impregnation. The
results shows that PEG act as a better surfactant to produce CaO/MgO-P catalyst it
indicated by the particle size of catalyst was about 377 nm, surface area (39 m2
/g),
pore volume (0.0322 m3
/g) and the basicity (7.8 mmol/g). The optimal conditions
transesterification reaction of coconut oil with CaO/MgO-P were achieved at:
methanol:oil ratio (1:9), CaO/MgO-P catalyst load (5%), and the reaction
temperature (125 °C) to yield biodiesel of 81.76%. The presence of NiO provide an
acidic- and basic- sites on NiO/CaO/MgO catalyst which can improve up to 90%
biodiesel yield. The kinetics of the transesterification reaction with a
NiO/CaO/MgO catalyst controlled by a pseudo first order with a value of A= 35.07
min-1
and a value of Ea = 24.47 kJ/mol. The thermodynamic parameters such as
ΔH, ΔS and ΔG were estimated to be 21.31 kJ/mol, -0.226 kJ/mol dan 111.259
kJ/mol respectively. The produced biodiesel properties including kinematic,
density, flash point, acid number, and carbon residue of biodiesel were 1.93 mm2
/s,
0.86 g/cm3
, 137 °C, 0.27 mg KOH/g, dan 0.22%, respectively. The reusability test
of the NiO/CaO/MgO catalyst showed that the catalyst is stable during 2 cycle with
the yield of biodiesel of 89.00 % at the first cycle dan drastically decreased to 51.95
% at the fourth cycle.

Item Type:	Thesis (Doctoral)
Uncontrolled Keywords:	Batu kapur, Biodisel, CaMg(CO3)2, minyak nabati, NiO/CaO/MgO
Subjects:	Q Science > QD Chemistry > QD501 Catalysis. Catalysts. T Technology > TD Environmental technology. Sanitary engineering > TD195.B56 Biomass energy
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47001-(S3) PhD Thesis
Depositing User:	Nuni Widiarti
Date Deposited:	04 Aug 2021 00:48
Last Modified:	04 Aug 2021 00:49
URI:	http://repository.its.ac.id/id/eprint/84754

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