dwina moentamaria, dwina
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HIDROLISIS MINYAK KELAPA DENGAN LIPASE TERIMOBILISASI ZEOLIT PADA PEMBUATAN PERISA ALAMI moentamaria, dwina; Agaian, Girlian; Ridhawati, Meilita Mustika; Chumaidi, Achmad; Hendrawati, Nanik
Jurnal Bahan Alam Terbarukan Vol 5, No 2 (2016): December 2016 [Nationally Accredited]
Publisher : Semarang State University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v5i2.7507


Free Fatty acid  resulting from hydrolisis of  various types of oil enzymatically has been great interest recently to save energy, in other hand  that the product are environmentally friendly.  Lipases as biocatalysts for synthesis reactions  will  be  dissolved with the product, making difficult their reuse. Efficiency can be done with the use of enzyme immobilization, which can be used for repeated reaction. The products of free fatty acids from coconut oil by hydrolysis of lipase can be used as a natural substrate for making flavor  that can be consumed and safe for health. The effect of free lipase and  immobilization of lipase on hydrolisis  were studied.   Reaction time of hydrolisis was varied as 30, 60, 90, 120 and 150 minutes. The  variation  of concentration of lipase  addition was 4, 5, 6, 7 and 8 % .  The types of treatment were used in this research free lipase and the immobilized lipase. The results shows that the highest conversion on hydrolisis of coconut oil  by using free lipase treatment  was performed by 6 % of lipase addition  with reaction time 60 minutes that are 52,31%. While, the highest conversion on hydrolisis of coconut oil by using the immobilized lipase was shown  by 8% of lipase addition with reaction time 120 minutes that is 56,01%.  The results of the hydrolysis process in the form of fatty acid was used as the base material esterification process resulting ester product (natural flavor). Ester yield was produced by free lipase esterification was 28,21 and 32,14 % in immobilized  lipase  esterification.
KINETIC MODELING OF SERIES REACTION CH4-CH3OH-DME WITH CuO-ZnO/gamma-Al2O3 CATALYST Chumaidi, Achmad; Moentamaria, Dwina; Murdani, Anggit
Jurnal Bahan Alam Terbarukan Vol 7, No 1 (2018): June 2018 [Nationally Accredited]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v7i1.11403


A kinetic model was proposed for the synthesis of methane to be dimethyl ether (DME) in one reaction step from (CH4 + O2) and (CH3OH) to dimethyl ether using kinetic CuO-ZnO /gAl2O3 catalyst parameters. The bifunctional catalyst of the series kinetic reaction model according to the experimental results obtained under isothermal conditions in a pipe flow reactor under various operating conditions: 225-325 ° C; 10 bar gauge; Residence time, 16-57.0 (g Catalyst) hour (mole CH4) -1. An important step for modeling is the synthesis of methanol from (CH4 + O2) and the synthesis of (CH3OH to DME) is methanol dehydration (very fast), and water-shifting and CO2 (equilibrium) reactions. The effects of water inhibition and CO2 were also taken into account in the synthesis of methanol and the formation of hydrocarbons. The dehydration advantage of methanol can achieve higher yields above 60 % methanol that was converted to DME and the remaining 5% methanol if (CH4 + O2) comes in at 10 bar gauge and 375 ° C. At higher temperatures produces CO2 and H2O. Methane-methanol-DME series reaction model follows single-order gas phase reaction to methane and methanol with k1 = 0.195 minutes-1 and k2 = 0.115 minutes-1 The time and maximum concentration occurs in the formation of methanol constituents 9.5 minutes and 0.44 mole
Jurnal Bahan Alam Terbarukan Vol 7, No 2 (2018): December 2018 [Nationally Accredited]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v7i1.11399


The enzymatic hydrolysis of palm oil can be conducted by using lipase produced from Mucor miehei to produce free fatty acid. This study aimed to compare the usage of lipase as free enzyme and as immobilized enzyme on zeolite matrix in the hydrolysis of palm oil as triglyceride producing free fatty acids which highly needed in various industrial sectors. Immobilization is an alternative hydrolysis reaction due to its usage on repetitive reaction, makes lipase reuseable, hence the whole process becomes efficient, and with moderate operational conditions. Solvent free reaction is applied, because the produced free fatty acids can be used directly in food, health, and natural flavorings industry. The palm oil used in the hydrolysis contains 0.815% initial free fatty acids as palmitate, in which water then added to it in weight ratio 1:3. Each effect of free lipase and immobilized lipase addition is 4%, 5%, 6%, 7%, 8%, and time reaction is 30, 60, 90, 120, 150 minutes are used as index to determine the amount of free fatty acids produced.  The results showed that Immobilized lipase has better ability than the free one in hydrolysis of triglyceride in palm oil producing free fatty acid with 8% lipase addition and time reaction of 120 minutes. Palm oil hydrolysis using free lipase produced the highest FFA of 1.9747% after the addition of 5% lipase concentrate, with time reaction of 60 minutes. Meanwhile, palm oil hydrolysis using immobilized lipase produced the highest FFA of 1.9747% after the addition of 8% lipase concentrate, with time reaction of 120 minutes.