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Ultrasound Assisted Esterification of Rubber Seed Oil for Biodiesel Production Widayat, Widayat; Fajar Tamtomo Kiono, Berkah
International Journal of Renewable Energy Development Vol 1, No 1 (2012): February 2012
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.1.1.1-5

Abstract

Production of biodiesel is currently shifting from the first to the second generation inwhich the raw materials are mostly from non-edible type oils and fats. Biodiesel production iscommonly conducted under batch operation using mechanical agitation to accelerate masstransfers. The main drawback of oil esterification is the high content of free fatty acids (FFA) whichmay reduce the yield of biodiesel and prolong the production time (2-5 hours). Ultrasonificationhas been used in many applications such as component extraction due to its ability to producecavitation under certain frequency. This research is aimed to facilitate ultrasound system forimproving biodiesel production process particularly rubber seed oil. An ultrasound unit was usedunder constant temperature (40oC) and frequency of 40 Hz. The result showed that ultrasound canreduces the processing time and increases the biodiesel yield significantly. A model to describecorrelation of yield and its independent variables is yield (Y) = 43,4894 – 0,6926 X1 + 1,1807 X2 –7,1042 X3 + 2,6451 X1X2 – 1,6557 X1X3 + 5,7586 X2X3 - 10,5145 X1X2X3, where X1 is mesh sizes, X2ratio oil: methanol and X3 type of catalyst.
ENTREPRENEURIAL ATTITUDE AND STUDENTS BUSINESS START-UP INTENTION: A PARTIAL LEAST SQUARE MODELING Widayat, Widayat; Ni matuzahroh, Ni matuzahroh
Jurnal Manajemen dan Kewirausahaan (Journal of Management and Entrepreneurship) Vol 19, No 1 (2017): MARCH 2017
Publisher : Institute of Research and Community Outreach - Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (379.261 KB) | DOI: 10.9744/jmk.19.1.46-53

Abstract

This article is designed to examine the role of the entrepreneurial spirit, education and in build­ing­ an attitude about working as an entrepreneur, and his influence on the intention to start a business, to the students. Data were collected using a questionnaire has been prepared and maintained the validity and relia­bility. Questionnaires given to the respondent students were selected as samples at several universi­ti­es in Malang, East Java, Indonesia. The collected data were analyzed by using Partial Least Square. The a­­na­­ly­sis showed entrepreneurial spirit and education contribute to the formation of entrepreneurial atti­tu­des. Attitudes are formed encourage entrepreneurship intentions to start a business significantly.
PEMBUATAN BIODIESEL DARI MINYAK GORENG BEKAS DENGAN PROSES CATALYTIC CRACKING Buchori, Luqman; Widayat, Widayat
TEKNIK Volume 28, Nomor 2, Tahun 2007
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (395.817 KB) | DOI: 10.14710/teknik.v28i2.2116

Abstract

Crude oil is a source of energy which is not be renewable. This fact motivates so much countries ineconomizing on fuel. Many researches have been done to gets another fuel substitute the crude oil.Biodiesel is represented as fuel instead of diesel fuel, and it is produced from vegetable oil. In the otherside, ex-cooking oil is waste-product from food industry, restaurant and household which is potential tobe alternative fuels because of the high contents of carbon and hydrogen atoms. Commonly the biodieselmade from vegetable oil by esterification and transesterification process. But if using esterification andtransesterification process to ex-cooking oil material, it is not economically feasible because the processmakes another reaction between alkaly catalist and oil to produce soap. One of biodiesel process iscatalytic cracking of the ex-cooking oil. This research is aimed to analyze zeolite catalist size effect(0.125mm; 0.3375mm; 0.425mm; 0.85mm; 1.18mm), and acid concentration on the product (2N; 3N;4N). This result shows that at 4N acid concentration and 0.125 mm zeolite catalist size is optimal whichcan reach diesel specification.
STUDI PENGARUH METODE PEMBUATAN DAN SUMBER BAHAN BAKU PADA PROSES PRODUKSI KATALIS DARI ZEOLIT ALAM Widayat, Widayat; Satriadi, H; Roesyadi, Achmad; Rachimoellah, H M
METANA Vol 9, No 01 (2013): Juli 2013
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (201.561 KB) | DOI: 10.14710/metana.v9i01.7206

Abstract

Abstract Indonesia has the potential for considerable natural zeolites. This natural zeolites, silica deposits typically have amounted to 60%, it also contains components of alumina. Silica and alumina oxide compound that can be used as a catalyst, particularly in the process of dehydration. This research aims to study the influence of the method of manufacture of catalysts in the production process of natural zeolite catalyst. The observed response is the surface area in comparison with silica, alumina and kristalitas. The surface area is measured by the method kristalitas and BET with XRD analysis as well as the composition of the silica-alumina with AAS. The methods used in this research is the process of exchanging ions-development with alcohol and dealuminiation process with hydrochloric acid solution. The raw materials used are natural zeolite from Malang, Lampung Province and Regency of Gunung Kidul. The results showed that dealuminasi process with hydrochloric acid produces a better surface area compared to the ion exchange process and development with alcohol. Besides the resulting catalyst with silicate dealuminasi process is a catalyst if the raw material of the Regency of Gunung Kidul and mordenite type if the raw materials used originate from Malang. Key words : Zeolite catalyst, natural zeolites, surface area, crystallite,Si/Al comparison
PRODUCTION OF INDUSTRY SALT WITH SEDIMENTATION – MICROFILTRATION PROCESS: OPTIMAZATION OF TEMPERATURE AND CONCENTRATION BY USING SURFACE RESPONSE METHODOLOGY Widayat, Widayat
TEKNIK Volume 30, Nomor 1, Tahun 2009
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (385.648 KB) | DOI: 10.14710/teknik.v30i1.1826

Abstract

The salt of sodium chloride commonly used consumption in house , so as a raw material in industry. Thequality of salt depends on sodium chloride concentration. The objective of this research is obtained ofoptimum condition in production of salt industry by using sedimentation and microfiltration process. Theoptimization used surface response methodology and analysis by Statistica 6 software. The responseperceived is NaCl concentration in product. The experiments do by mixing stearic acid with NaOH solutionto product stearic sodium. Then, the solution mixed with sea water, so the white solid will be emerge, thereare stearic calcium and stearic magnesium. And so filtrate evaporated until to obtain salt. TheMathematical model for reduction of Ca2+ and Mg2+ are1 222 221 1 Y = 93,3185 + 1,0967 X + 0,1909 X +1,0682 X - 0,2333 X - 0,3376 X X , with maximum conversion is94,46% at temperature 82,42oC and stearic sodium concentration 14,16%(v/v). The maximum of NaClconcentration is 96,19% at temperature 81,54oC and stearic sodium concetration 13,11 %(v/v). Themathematical model for NaCl production is1 222 221 1 Y = 92,7596 - 0,3443 X - 3,3706 X + 2,9553 X - 0,9562 X - 1,9272 X X . The results of NaCl not yetfulfilled with SNI industry salt. The NaCl concetration in SNI is 98,5%. So, this process is nt aplicable forproductiob salt industry in Indonesia.
PROSES PRODUKSI KATALIS ZEOLIT X DAN UJI AKTIFITAS DALAM PROSES PENUKARAN ION KALSIUM Widayat, Widayat; Sadikky DP, A.; Anggraeni, H.
TEKNIK Volume 33, Nomor 1, Tahun 2012
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (335.49 KB) | DOI: 10.14710/teknik.v33i1.3792

Abstract

Zeolie is a material that used in chemical process industry. Zeolite commonly used as catalyst, adsorbent adnion exchanger.Zeolite can be obtained from natural resources and synthetic in industry. The type of zeolitethatused as ion exchanger zeolite X. Zeolite X can produced hy uding hydrogel process and clay process. Thisreasearch was study influencing of temperature and ratio sodium hydroxide (NaOH) to water glass in zeolite Xpreparation. Crystallity of zeolite X was analyzed with X-ray diffraction (XRD) and the activity was used asion exchanger. Response variabel in this research is weight of zeolite X and the capability as ion exchanger.Ion exchange test that used for exchange of calsium. Calsium ion was analizyed by using complexometrymethod. The results of this research shown that zeolit X was obtained in temperature 100oC and rationweight of sodium hidroxide (NaOH) to water glass 1:2. The zeolite X can be used as ion exchanger especiallyfor calsium ion.
KINETIC STUDY OF THE UTILISATION OF DIFFERENT SUBSTRATES TO LACTIC ACID USING Lactobacillus delbrueckii Abdullah, Abdullah; Mat, Hanapi bin; Widayat, Widayat
METANA Vol 6, No 01 (2009): April 2009
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5667.593 KB) | DOI: 10.14710/metana.v6i01.1830

Abstract

Abstract   Lactic acid fermentation includes several reactions in association with the microorganism growth.  A kinetic study was performed of the utilisation of multiple substrates to lactic acid using lactobacillus delbrueckii. Batch fermentation was performed to study effect of different substrates such as glucose, fructose and sucrose. The objective of this research is to study kinetics grow microbial. A anaerobic fermentation were studied in 3 litres stirred fermentor ( Biostat B Model) with working volume of 1 liter, temperature : 40 oC, pH = 6.0, inoculums size : 5% , sugar concentration =  20 g/1. During the first hours of fermentation, glucose and fructose accumulated in the medium and the rate of  hydrolysis of sucrose to glucose and fructose was faster than conversion of these substrate. The maximum concentration of glucose and fructose was 5.82 and 5. 14 g/l respectively. The sucrose, glucose, and fructose consumption completely utilized at 56, 68, and 104 hours, respectively. Kinetic parameter for maximum .specific growth rate in glucose, fructose and sucrose is 0.103, 0.0448, and 0.0398 (h-1), respectively. The saturation constant is 2.13, 2.67, and 3.32 g/1.   Key Words: Kinetic Study, Sugars, Lactic Acid, Maximum Specific Growth Rate and Saturation Constant
REPOSISI BUDAYA DALAM MEWUJUDKAN SUSTAINABILITAS PEMBANGUNAN EKONOMI BANGSA Widayat, Widayat
Jurnal Bestari No 42 (2009)
Publisher : Jurnal Bestari

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (97.28 KB)

Abstract

Culture as a unique characteristic of a nation has capital function in creating sustainability of economic development. In the culture, capital function can be seen from two aspects; as an instrument and constituent. Furthermore, culture contains physical (tangible) and non-physical (intangible) aspects that are useful in building nation's competitive and advantageous competence, as well as a source of national income.
Kinetic Study on Ultrasound Assisted Biodiesel Production from Waste Cooking Oil Widayat, Widayat; Hadiyanto, H; Sasongko, Setia Budi
Journal of Engineering and Technological Sciences Vol 47, No 4 (2015)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (212.602 KB) | DOI: 10.5614/j.eng.technol.sci.2015.47.4.3

Abstract

The objective of this research was to study  a kinetic model of biodiesel production from waste cooking oil assisted by ultrasound power. The model considered the biodiesel production process as a 2nd order reversible reaction, while its kinetic parameters were estimated using MATLAB, based on data extracted from Hingu, et al. [1]. The data represented experiments under low-frequency ultrasonic wave (20 kHz) and variations of temperature, power, catalyst concentration, and alcohol-oil molar ratio. Statistical analysis showed that the proposed model fits well to the experimental data with a determination coefficient (R2) higher than 0.9.
Biodiesel Production from Rubber Seed Oil via Esterification Process Widayat, Widayat; Suherman, S
International Journal of Renewable Energy Development Vol 1, No 2 (2012): July 2012
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.1.2.57-60

Abstract

One promise source of alternative energy is biodiesel from rubber seed oil, because the raw materials available in plentiful quantities and can be renewed. In addition, the rubber seed is still lack of utilization, and Indonesia is one of the largest rubbers producing country in the world. The objective of this research is to studied on biodiesel production by esterification process. Parameters used in this study are the ratio of catalyst and temperature and its influence on the characteristics of the resulting biodiesel product. Characterization of rubber seed include acid content number analysis, saponification numbers, density, viscosity, iodine number, type of free fatty acids and triglyceride oils. The results of analysis showed that rubber seed oil content obtained is 50.5%. The results of the GCMS analysis showed that a free fatty acid level in rubber seed is very high. Conversion into bio-diesel oil is obtained by at most 59.91% and lowest 48.24%.