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EVALUASI MANAGEMENT CONTROL SYSTEM DALAM MENINGKATKAN CONTROL PADA AKTIVITAS OPERASIONAL PADA CV “X” DI SURABAYA Ariyanto, Teguh
CALYPTRA : Jurnal Ilmiah Mahasiswa Universitas Surabaya Vol 3, No 2 (2014): CALYPTRA : Jurnal Ilmiah Mahasiswa Universitas Surabaya
Publisher : University of Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Bisnis Keluarga merupakan badan usaha yang sering kali dijumpai dibanyak negara. Bisnis keluarga sendiri merupakan sumber penciptaan kekayaan pribadi dan juga merupakan perekonomian regional khususnya wilayah asia. Bisnis keluarga sendiri tidak terlepas dari suatu masalah. Adapun masalah yang dihadapi antara bisnis keluarga antara satu dan yang lain berbeda-beda. Oleh karena itu diperlukan sebuah sistem pengendalian manajemen untuk mengatasi suatu masalah tersebut. Pada penelitian ini obyek yang digunakan adalah CV “X” yang dimana juga merupakan bisnis keluarga yang bergerak pada bidang jasa yang khususnya jasa perbaikan kapal serta kontraktor. Penelitian juga merupakan applied research yang bertujuan untuk memberikan rekomendasi pada CV “X” Surabaya mengenai sistem pengendalian manajemen dalam upaya untuk meningkatkan kontrol pada aktivitas operasionalnya. Pendekatan pada penelitian ini adalah pendekatan secara kualitatif. Temuan yang didapatkan selama observasi atau masa penelitian  adalah masih lemahnya kontrol pada aktivitas operasional pada CV “X” yang dimana berdampak pada penyelesaian pekerjaan serta kualitas hasil yang tidak sesuai dengan harapan dari seorang pemilik. Dalam hal ini CV “X” perlu memperbaiki sistem pengendalian manajemen agar control yang ada dalam CV “X” meningkat dan pekerjaan dapatterselesaikan sesuai tepat pada waktunya dan kualitas hasil pekerjaan sesuai dengan apa yang diharapkan.
MODIFICATION OF IRON OXIDE CATALYSTS SUPPORTED ON THE BIOMASS BASED ACTIVATED CARBON FOR DEGRADATION OF DYE WASTEWATER Amelia, Shinta; Sediawan, Wahyudi Budi; Mufrodi, Zahrul; Ariyanto, Teguh
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.v7i2.17174

Abstract

Methylene blue is one of the dyes in textile industries which has a negative impact on the environment. This compound is very stable, so it is difficult to degrade naturally. Methylene blue can be harmful to the environment if it is in a very large concentration, because it can increase the value of Chemical Oxygen Demand (COD) which can damage the balance of environment ecosystem. Adsorption method by using activated carbon as the adsorbent is one of the most efficient and effective techniques in dye removal due to its large adsorption capacity. However, the adsorption method using activated carbon only removes the pollutant compounds to other media or phases. Other method that can be used includes Advanced Oxidation Processes (AOPs). This method has the advantage of being able to degrade harmful compounds in the waste through oxidation (oxidative degradation) processes. One method of AOPs is the process by using Fenton reagents. This study was aimed to prepare and characterize iron oxide/porous activated carbon catalyst. The type of porous activated carbon used was carbon from biomass derived carbon with microporous character. This biomass carbon is obtained from renewable natural products, namely coconut shell.The kinetics and adsorption models in the material will be derived and evaluated from the research data. Based on the research, it can be concluded that catalytic degradation is very effective for degradation of dye wastewater. Methylene blue degradation increases with the use of Fe2O3/activated carbon catalyst and the addition of hydrogen peroxide as the Fenton reagent. In addition, the pore structure difference in the catalyst also had a significant effect on the methylene blue degradation reaction resulting in increased capacity of methylene blue degradation reactions.
ADSORPTION OF ETHYLENE USING COBALT OXIDE-LOADED PILLARED CLAY Satwikanitya, Pani; Prasetyo, Imam; Fahrurrozi, Moh.; Ariyanto, Teguh
Journal of Engineering and Technological Sciences Vol 52, No 3 (2020)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2020.52.3.9

Abstract

Clay is an abundant material that is widely used as an adsorbent in pristine or pillared form. Pillared clays feature better properties, e.g. higher specific surface area, thus they can adsorb a higher quantity of adsorbates compared to pristine material. In this work, a preparation of pillared clay using Indonesian natural bentonite and its potential for ethylene removal are presented. The novelty is that a pillaring agent of cobalt (mixed with aluminum) was used, which not only served as a pillar but also as an active metal adsorbent for ethylene. Natural bentonite was pillared using Al (NO3)3.9H2O and Co (NO3)2.6H2O. The resulting material was then calcined at 250 °C. The final material was characterized by N2-sorption analysis, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. The cobalt to aluminum ratios used were 1:9, 1:3, 1:1, 1:1/3, and 1:0. From characterization, the Co-Al pillared bentonite featured a specific surface area of up to 114 m2/g (pristine bentonite = 42 m2/g). In the adsorption test, an enhanced ethylene uptake of up to 6 times (at ambient temperature) compared to pristine bentonite was obtained. Thus, the results highlight the potential of cobalt oxide/pillared clay as ethylene scavenger.
The Effect of Amine Types on Breakthrough Separation of Methane on Biogas Masruroh, Kuni; Cahyono, Rochim Bakti; Prasetyo, Imam; Ariyanto, Teguh
International Journal of Renewable Energy Development Vol 10, No 2 (2021): May 2021
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2021.33514

Abstract

Methane (CH4) and carbon dioxide (CO2) are the main components of a renewable energy source of biogas. Separation of CO2 from biogas is significantly important to improve biogas performance, due to heating value in biogas depends on the concentration of methane. One of the gas separation technologies that has been widely used in chemical industries is carbon molecular sieve (CMS). This research explores the potential of CMS for biogas purification. CMS was prepared by modification of palm kernel shell-derived porous carbon using amine groups such as monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP), and diethanolamine (DEA). The effect of amine types on the separation parameters was studied by using a breakthrough experiment to obtain the most potential CMS materials. The methods of this research include the process of carbon oxidation using hydrogen peroxide, impregnation with an amine group, characterization of the CMS material obtained, CO2 and CH4 gas separation testing with a breakthrough system. The CMS was characterized by using N2 sorption analysis, fourier transform infrared spectroscopy, and scanning electron microscopy. The breakthrough experiment showed that CMS-MEA had the highest performance for separating CO2 and CH4 gases. In addition, the results also showed that loading of amine groups on carbon caused an increase in the uptake capacity of CO2, and the highest capacity was achieved by CMS-MEA of 13.2 mg/g.
Adsorption of Ethylene using Cobalt Oxide-Loaded Pillared Clay Pani Satwikanitya; Imam Prasetyo; Moh. Fahrurrozi; Teguh Ariyanto
Journal of Engineering and Technological Sciences Vol. 52 No. 3 (2020)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2020.52.3.9

Abstract

Clay is an abundant material that is widely used as an adsorbent in pristine or pillared form. Pillared clays feature better properties, e.g. higher specific surface area, thus they can adsorb a higher quantity of adsorbates compared to pristine material. In this work, a preparation of pillared clay using Indonesian natural bentonite and its potential for ethylene removal are presented. The novelty is that a pillaring agent of cobalt (mixed with aluminum) was used, which not only served as a pillar but also as an active metal adsorbent for ethylene. Natural bentonite was pillared using Al (NO3)3.9H2O and Co (NO3)2.6H2O. The resulting material was then calcined at 250 °C. The final material was characterized by N2-sorption analysis, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. The cobalt to aluminum ratios used were 1:9, 1:3, 1:1, 1:1/3, and 1:0. From characterization, the Co-Al pillared bentonite featured a specific surface area of up to 114 m2/g (pristine bentonite = 42 m2/g). In the adsorption test, an enhanced ethylene uptake of up to 6 times (at ambient temperature) compared to pristine bentonite was obtained. Thus, the results highlight the potential of cobalt oxide/pillared clay as ethylene scavenger.
Kinetika Kalsinasi Seria Zirkonia dari Proses Gelasi Eksternal Fera Wahyuningsih; Wahyudi Budi Sediawan; Teguh Ariyanto; Sri Widiyati
Jurnal Rekayasa Proses Vol 10, No 1 (2016)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (681.881 KB) | DOI: 10.22146/jrekpros.34423

Abstract

Calcination process is one of the important steps in the synthesis of nuclear fuel particles for High Temperature Reactor (HTR). In this work, the calcination process of Ceria-Stabilized Zirconia (CSZ) was carried out. The aims of the study are to study the kinetic modelling of calcination process of CSZ kernel, to determine the suitable operation condition, and to observe physical characters of the calcined material. The feed of calcination process was material prepared by an external gelation. The calcination was conducted from room temperature to 500 oC with heating rate of 1 and 2 °C/min. CSZ kernel per grain was weighted and the diameter was measured during calcination process, hence determining the weight loss and size change. The results showed that there was a weight loss of kernel during calcination process. When the weight of grain reached a constant value, the process of calcination was considered complete. ABSTRAKProses kalsinasi merupakan salah satu tahap penting dalam pembuatan inti bahan bakar reaktor nuklir suhu tinggi (HTR). Penelitian mengenai proses kalsinasi seria zirkonia (CSZ) sudah banyak dilakukan, namun lebih ditekankan pada pengamatan sifat fisik dan mekanik. Penelitian ini bertujuan untuk mempelajari model kinetika proses kalsinasi kernel CSZ dan mencari kondisi operasi yang cocok untuk proses tersebut. Kalsinasi dilakukan dengan bahan baku yang berasal dari proses gelasi eksternal pada berbagai suhu hingga suhu 500 oC dengan laju pemanasan 1 oC/menit dan 2 oC/menit. Penimbangan berat dan pengukuran diameter per butir kernel CSZ setelah proses kalsinasi dilakukan untuk mengetahui berat yang hilang dan penyusutan butir selama proses tersebut. Ketika proses kalsinasi, terjadi penurunan berat butir kernel seiring dengan kenaikan suhu kalsinasi. Pada saat berat butir mencapai kestabilan, proses kalsinasi dapat dianggap berakhir.
Kajian Dampak Lingkungan pada Sistem Produksi Listrik dari Limbah Buah Menggunakan Life Cycle Assessment Fajar Marendra; Anggun Rahmada; Agus Prasetya; Rochim Bakti Cahyono; Teguh Ariyanto
Jurnal Rekayasa Proses Vol 12, No 2 (2018)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (752.488 KB) | DOI: 10.22146/jrekpros.36425

Abstract

A B S T R A C TProducing biogas by anaerobic digestion (AD) is a promising process that can simultaneously provide renewable energy and dispose solid waste safely. However, this process could affect environment e.g. due to greenhouse gas emissions. By life cycle assessment (LCA), we assessed the environmental impact (EI) of an integrated fruit waste-based biogas system and its subsystems of Biogas Power Plant Gamping. Data were collected from an actual plant in Gamping, Sleman, Yogyakarta, Indonesia that adopted a wet AD process at mesophilic condition. The results showed that the global warming potential (GWP) emission of the system reached 81.95 kgCO2-eq/t, and the acidification potential (AP), eutrophication potential (EP), human toxicity potential (HTPinf) and fresh water ecotoxicity (FAETPinf) emissions were low. The EI was mainly generated by two subsystems, namely, the electricity generation and the digestate storage. A comparison analysis showed that the GWP become the main contributor of environmental loads produced by Biogas Plant Gamping, Suazhou Biogas Model, Opatokun Biogas Model, Opatokun Pyrolisis Model, dan Opatokun Integrated System Anaerobic Digestion and Pyrolisis. The GWP impact control and reduction could significantly reduce the EI of the system. It has been shown that improving the technology of the process, the electricity generation and the digestate storage will result in the reduction of EI of the biogas system.Keywords: environmental impact; fruit waste; life cycle assessment (LCA); renewable energyA B S T R A KProduksi listrik dari biogas dengan anaerobic digestion (AD) merupakan proses yang menjanjikan karena dapat menghasilkan energi listrik dan penanganan limbah padat dengan aman. Namun, proses ini mempengaruhi lingkungan akibat emisi gas rumah kaca. Penilaian dampak lingkungan (environmental impact atau EI) sistem biogas berbasis limbah terpadu dan subsistemnya terhadap Biogas Power Plant Gamping (BPG) dilakukan dengan metode life cycle assesement atau LCA. Data dikumpulkan dari plant yang sebenarnya di Gamping, Sleman, Yogyakarta, Indonesia yang mengadopsi proses AD basah pada kondisi mesofilik. Potensi pemanasan global (global warming potential atau GWP) dari sistem mencapai 81,95 kgCO2-eq/t, sedangkan potensi keasaman (acidification potential atau AP), potensi eutrofikasi (eutrophication potential atau EP), potensi toksisitas manusia (human toxicity potential atau HTPinf) dan ekotoksisitas air (fresh water ecotoxicity atau FAETPinf) potensi emisinya cukup rendah. Potensi EI terutama dihasilkan oleh dua subsistem, yaitu, pembangkit listrik dan penyimpanan digestate. Analisis perbandingan menunjukkan bahwa dampak GWP menjadi kontributor utama dari beban lingkungan yang dihasilkan oleh Biogas Plant Gamping, biogas model Suazhou, biogas model Opatokun, model pirolisis Opatokun, serta model integrasi AD dan pirolisis Opatokun. Pengendalian dan pengurangan dampak GWP secara signifikan dapat mengurangi EI dari sistem. Telah terbukti bahwa peningkatkan teknologi proses, pembangkit listrik dan penyimpanan digestate akan menghasilkan pengurangan EI dari sistem biogas.Kata kunci: dampak lingkungan; energi terbarukan; life cycle assessment (LCA); limbah buah
Kinetika Kalsinasi Seria Zirkonia dari Proses Gelasi Eksternal Fera Wahyuningsih; Wahyudi Budi Sediawan; Teguh Ariyanto; Sri Widiyati
Jurnal Rekayasa Proses Vol 10, No 1 (2016)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.34423

Abstract

Calcination process is one of the important steps in the synthesis of nuclear fuel particles for High Temperature Reactor (HTR). In this work, the calcination process of Ceria-Stabilized Zirconia (CSZ) was carried out. The aims of the study are to study the kinetic modelling of calcination process of CSZ kernel, to determine the suitable operation condition, and to observe physical characters of the calcined material. The feed of calcination process was material prepared by an external gelation. The calcination was conducted from room temperature to 500 oC with heating rate of 1 and 2 °C/min. CSZ kernel per grain was weighted and the diameter was measured during calcination process, hence determining the weight loss and size change. The results showed that there was a weight loss of kernel during calcination process. When the weight of grain reached a constant value, the process of calcination was considered complete. ABSTRAKProses kalsinasi merupakan salah satu tahap penting dalam pembuatan inti bahan bakar reaktor nuklir suhu tinggi (HTR). Penelitian mengenai proses kalsinasi seria zirkonia (CSZ) sudah banyak dilakukan, namun lebih ditekankan pada pengamatan sifat fisik dan mekanik. Penelitian ini bertujuan untuk mempelajari model kinetika proses kalsinasi kernel CSZ dan mencari kondisi operasi yang cocok untuk proses tersebut. Kalsinasi dilakukan dengan bahan baku yang berasal dari proses gelasi eksternal pada berbagai suhu hingga suhu 500 oC dengan laju pemanasan 1 oC/menit dan 2 oC/menit. Penimbangan berat dan pengukuran diameter per butir kernel CSZ setelah proses kalsinasi dilakukan untuk mengetahui berat yang hilang dan penyusutan butir selama proses tersebut. Ketika proses kalsinasi, terjadi penurunan berat butir kernel seiring dengan kenaikan suhu kalsinasi. Pada saat berat butir mencapai kestabilan, proses kalsinasi dapat dianggap berakhir.
Kajian Dampak Lingkungan pada Sistem Produksi Listrik dari Limbah Buah Menggunakan Life Cycle Assessment Fajar Marendra; Anggun Rahmada; Agus Prasetya; Rochim Bakti Cahyono; Teguh Ariyanto
Jurnal Rekayasa Proses Vol 12, No 2 (2018)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.36425

Abstract

A B S T R A C TProducing biogas by anaerobic digestion (AD) is a promising process that can simultaneously provide renewable energy and dispose solid waste safely. However, this process could affect environment e.g. due to greenhouse gas emissions. By life cycle assessment (LCA), we assessed the environmental impact (EI) of an integrated fruit waste-based biogas system and its subsystems of Biogas Power Plant Gamping. Data were collected from an actual plant in Gamping, Sleman, Yogyakarta, Indonesia that adopted a wet AD process at mesophilic condition. The results showed that the global warming potential (GWP) emission of the system reached 81.95 kgCO2-eq/t, and the acidification potential (AP), eutrophication potential (EP), human toxicity potential (HTPinf) and fresh water ecotoxicity (FAETPinf) emissions were low. The EI was mainly generated by two subsystems, namely, the electricity generation and the digestate storage. A comparison analysis showed that the GWP become the main contributor of environmental loads produced by Biogas Plant Gamping, Suazhou Biogas Model, Opatokun Biogas Model, Opatokun Pyrolisis Model, dan Opatokun Integrated System Anaerobic Digestion and Pyrolisis. The GWP impact control and reduction could significantly reduce the EI of the system. It has been shown that improving the technology of the process, the electricity generation and the digestate storage will result in the reduction of EI of the biogas system.Keywords: environmental impact; fruit waste; life cycle assessment (LCA); renewable energyA B S T R A KProduksi listrik dari biogas dengan anaerobic digestion (AD) merupakan proses yang menjanjikan karena dapat menghasilkan energi listrik dan penanganan limbah padat dengan aman. Namun, proses ini mempengaruhi lingkungan akibat emisi gas rumah kaca. Penilaian dampak lingkungan (environmental impact atau EI) sistem biogas berbasis limbah terpadu dan subsistemnya terhadap Biogas Power Plant Gamping (BPG) dilakukan dengan metode life cycle assesement atau LCA. Data dikumpulkan dari plant yang sebenarnya di Gamping, Sleman, Yogyakarta, Indonesia yang mengadopsi proses AD basah pada kondisi mesofilik. Potensi pemanasan global (global warming potential atau GWP) dari sistem mencapai 81,95 kgCO2-eq/t, sedangkan potensi keasaman (acidification potential atau AP), potensi eutrofikasi (eutrophication potential atau EP), potensi toksisitas manusia (human toxicity potential atau HTPinf) dan ekotoksisitas air (fresh water ecotoxicity atau FAETPinf) potensi emisinya cukup rendah. Potensi EI terutama dihasilkan oleh dua subsistem, yaitu, pembangkit listrik dan penyimpanan digestate. Analisis perbandingan menunjukkan bahwa dampak GWP menjadi kontributor utama dari beban lingkungan yang dihasilkan oleh Biogas Plant Gamping, biogas model Suazhou, biogas model Opatokun, model pirolisis Opatokun, serta model integrasi AD dan pirolisis Opatokun. Pengendalian dan pengurangan dampak GWP secara signifikan dapat mengurangi EI dari sistem. Telah terbukti bahwa peningkatkan teknologi proses, pembangkit listrik dan penyimpanan digestate akan menghasilkan pengurangan EI dari sistem biogas.Kata kunci: dampak lingkungan; energi terbarukan; life cycle assessment (LCA); limbah buah
Removal of metronidazole from simulated wastewater using Fe/C catalyst with a combination of heterogenous Fenton and ozonation Panandita, Budi Satria; Prasetyo, Imam; Ariyanto, Teguh
Jurnal Rekayasa Proses Vol 17, No 2 (2023)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.75633

Abstract

This study examined roles of iron oxide/porous carbon material (Fe/C) for removing metronidazole in simulated wastewater by adsorption and then followed by a degradation using advanced oxidation process (H2O2, O3 and combination of H2O2/O3). Fe/C was produced by an impregnation of iron oxide precursors during resorcinol-formaldehyde synthesis followed by pyrolysis at 800 °C. For comparison, blank carbon (without iron loading) was also synthesized. The properties of porous carbon were investigated by SEM-EDX and N2-sorption analyzer. Blank carbon and Fe/C featured the specific surface area of 755 m2g-1 and 394 m2g-1, respectively. The loading of iron oxide altered the pore structures of material. The adsorption isotherm data were followed by the Langmuir isotherm model with metronidazole uptake up to 46.07 mg g-1 and 39.97 mg g-1 at 30oC by Fe/C and blank carbon. The degradation study was then carried out with catalyst dosage of 0.1 g/100 mL solution and 120 min reaction time at 30 oC. It is noticeably that, the degradation of metronidazole was better when a combination of H2O2/O3 was employed, compared with an individual of H2O2 or O3. Regarding the stability, Fe/C maintained its high activity upon four consecutive runs.