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Eksergi
Published by Universitas Pembangunan Nasional Veteran Yogyakarta
ISSN : 1410394X     EISSN : 24608203     DOI : -
Core Subject : Engineering,
Chemical Engineering, Chemistry & Bioengineering
Eksergi accepts manuscript in Chemical Engineering, with topics: separation in Chemical Engineering, Energy and related to Renewable or Sustainable energy, Process and Production of Chemical Engineering, Nanomaterial particle, Chemical engineering design and process control. All articles published by Eksergi are peer-reviewed. The types of paper considered for publication are original articles in basic and applied research, case studies, and critical reviews.
Arjuna Subject : -
Articles 201 Documents
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Fenomena dan Kecepatan Minimum Fluidisasi Widayati Widayati
Eksergi Vol 10, No 2 (2010): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v10i2.339

Abstract

Phenomenon and the minimum fluidization velocity (Umf) solid-gas depend of particle type, gas flow rate, column diameter and height of solids bed. This research was conducted on sand of quartz, iron and volcano Merapi (group B the particle) in the column with 6 cm diameter and height of the bed that varies are 6 cm, 8 cm and 10 cm. Observations began after the air with the lowest velocity flow from the bottom upwards through the bed. From the observations obtained a phenomenon that occurs is the fixed bed, bubbling fluidization and slugging fluidization. Umf in the height of bed 6 cm were 10.3 cm/sec, 7.3 cm/sec and 4.8 cm/sec. While at the height of bed 8 cm were 11.9 cm sec, 7.3 cm/sec and 5.1 cm/sec. and at the height of the bed 10 cm value (Umf)  obtained were 8.8 cm/sec, 8.8 cm/sec and 5.8 cm/sec. Based on theoretical, the Umf  for quartz sand was 12.0 cm/sec, iron sand 16.2 cm/sec and sand volcano Merapi 12.3 cm/sec. Thus, the value Umf, an experiment that comes closest to the value Umf theory only occurs for the use of quartz sand column diameter of 6cm and 8cm height of the bed.
Pengaruh pH dan Rasio COD:N Terhadap Produksi Biogas dengan Bahan Baku Limbah Industri Alkohol (Vinasse) Budiyono, Budiyono
Eksergi Vol 11, No 1
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v11i1.324

Abstract

 Industrial waste ethanol, which vinasse is one potential source to be processed into biogas. This study was conducted to assess the potential of vinasse waste and comparison nutrients needed to obtain biogas with optimum results. Experiments conducted in the digester volume 5L, operated at room temperature and neutral pH by varying the ratio of COD: N: P 800:7, 900:7, 1000:7 on vinasse mixture, rumen, urea and vinasse mixture , rumen, and NH4 HCO3  within 30 days. Respons which taken from this research are influence of pH, ratio of COD:N and nutrition to biogas production. The optimum condition of pH in producing biogas is at 7. Production of biogas produced at the optimum ratio of COD: N: P 800:7 is equal to 280 ml (0,96 ml biogas/mg TS COD) in a mixture of vinasse, rumen, urea and 3839 ml (13,73 ml biogas/mg TS COD) in a mixture of vinasse, rumen, NH4 HCO3  due to the comparison easier bacteria decompose organic compounds. While vinasse mixture, rumen, and NH4 HCO3  produces more biogas than vinasse mixture, rumen, urea may be due NH4 HCO3  to maintain the pH range so that the bacteria can survive.
Pengaruh Oil Sludge Pertamina Surabaya Terhadap Kuat Tekan Keramik Tradisional Adi Ilcham
Eksergi Vol 11, No 1
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v11i1.329

Abstract

 Oil sludge is the solidifying oils that lying on the open space around the fuel storage tank. Heaps of the waste continues to increase could lead to environmental pollution due to the waste containing heavy metal. This research aims to study the effect of oil sludge on the compressive strength of traditional ceramics within range of sintering temperature (600- 1000 0 C), sintering time (1-3 hours), and raw material compositions. The experiment begins by mixing the ceramic raw materials. Material was mixed with water and milled using Mortar Hand (milling). A cermic mold was used to get ceramic specimens. The mold dimension is length of 8 cm, 4 cm wide, and 2 cm high. The specimens were sintered in a furnace at different temperatures and holding time. Finally, the ceramics were observed its compressive strength. The results showed that the waste oil sludge can be involved in the manufacture of traditional ceramics. In the view of the compressive strength, the best conditions for fabricating traditional ceramics are oil sludge of 16.67% w., sintering temperature of 800 0  C, and sintering time of 2.5 hours.
Peluang dan Tantangan Komersialisasi Biodisel-Review Mahreni Mahreni
Eksergi Vol 10, No 2 (2010): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v10i2.335

Abstract

Hydrogen is one of the environmentally friendly fuel, however hydrogen is not always available due to continuously increasing energy demand and fossil fuel availability become more limited. Gap between demand and supply is essential to find alternative fuels. Biodiesel could be a substituent for fossil fuels, especially for hydrogen. Biodiesel could be made by mixing vegetable oils or fats with fossil fuel with a ratio of (5-20) wt.% however in a long time effect of this mixture can damage the engine. To overcome the problem, biodiesel can be synthesized via transesterification of oil and alcohol with the aid of acid or base catalyst to produce glycerol and FAME (Fatty Acid Methyl Ester). Challenges faced for the commercialization of biodiesel among others, (1) expensive raw material (edible oil), (2) reaction time and separation of the relatively long time (minimum 15 hours), (3) the use of acid catalysts still leaves the problem of corrosion and corrosion of machine tools and pollution to the environment by the catalyst. To make biodiesel competitive in the market, used oil (waste cooking oils, WCO), agricultural waste, and recent studies using microalgae could be used as source of biodiesel production. To shorten the reaction time, reaction was carried out using ultrasonic reactor technology and to minimize environmental pollution to use the solid catalyst. This paper will summarize on the adoption of latest technologies in producing biodiesel from used frying oil and microalgae.
Pemungutan Pektin dari Kulit dan Amapas Apel Secara Ekstraksi Purwo Subagyo
Eksergi Vol 10, No 2 (2010): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v10i2.340

Abstract

Apel dikonsumsi sebagai buah segar maupun produk olahan. Sebagai produk olahan (buah kaleng, jus, sari buah), apel menyisakan limbah berupa kulit dan ampas, yang kebanyakan digunakan subsitusi pupuk dan pakan ternak atau dibuang. Kandungan pektin dalam buangan tersebut belum termanfaatkan. Penelitian ini memanfaatkan limbah tersebut untuk dipungut kandungan pektinnya. Apel dikupas, sedang daging buah diperas, dipisahkan sari buahnya dan diambil ampasnya. Kulit dan ampas dikeringkan, kemudian diekstraksi dalam labu leher tiga dengan solven air pada suasana asam (dipakai, HCl). Ekstraksi dilakukan dengan variasi suhu (60, 70, 80, 90 dan 100 0C), pH (2; 2,5; 3; 3,5 dan 4), waktu (30, 60, 90, 120 dan 150) menit. Ekstrak disaring dalam keadaan panas, kemudian ditambahkan Aceton hingga terbentuk endapan. Endapan dicuci dengan Alkohol hingga netral dan dikeringkan dalam oven sampai beratnya kanstan, sebagai pektin kering. Kondisi operasi optimal dicapai pada suhu eketraksi 90 0C, dengan pH larutan untuk ampas (3,5), untuk larutan kulit pH 3, dan waktu operasi 90 menit. Pektin kering yang terpungut (rerata) pada kondisi operasi tersebut adalah 13,940 % (berat) untuk ampas dan 12,897 % (berat) untuk kulit apel.Perlu dilakukan uji kelayakan hasil jika pektin tersebut akan dimanfaatkan sebagai subsitusi bahan pangan, bahan pengobatan dan industri farmasi.
Pre-treatment Process of Biodiesel Production From Waste Cooking Oil Putri Restu Dewati; Achmad Halim Purbohandono; Arief Budiman
Eksergi Vol 11, No 1
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v11i1.318

Abstract

 Methyl ester of fatty acids known as biodiesel, synthesized from vegetable oils or animal fats, is a promising alternative fuel due to the limited resource of fossil fuel and the environment concern. There are large amount of low cost oil such as waste cooking oil that could be converted to biodiesel. However there is problem related to process of this low cost oil since they often contain large amounts of free fatty acid (FFA) that cannot be converted to biodiesel using alkalin ecatalyst. In this paper, a technique for reducing the FFA as pre-treatment in biodiesel production from waste cooking oil is studied. This pre-treatment step is aimed to esterify the FFA before trans-esterifying process of triglycerides with an alkaline-catalyst to complete the reaction. The main parameters of this process such as temperature, the molar ratio of methanol to acid catalyst, and catalyst loading were investigated to determine the optimum condition for converting of the FFA to usable esters. The result shows that the best condition for reducing of FFA was obtained at 65o C, with a molar ratio of oil to methanol of 1:6, and catalyst loading of 2 wt% H2SO4 .
Pirolisis Katalitik Tandan Kosong Sawit Menjadi Bio-oil dengan Katalis HZSM-5 Sunarno Sunarno
Eksergi Vol 11, No 1
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v11i1.325

Abstract

One of the alternative new energy sources is biomass. Biomass can be processes to produce bio-oil. The pyrolysis method was used to convert the palm empty fruit bunch from biomass to bio-oil. The purpose of this research are to study the influence of pyrolysis temperature with bio-oil yield and its properties. Pyrolysis process in slurry reactor with 50 grams palm empty fruit bunch, 500 ml thermo-oil and 2% HZSM-5 catalyst. Operating temperature variation (290,300,310 dan 3200 C) have been done. The result show that the optimum temperature obtained at 3200 C with bio-oil yield is 73.6%. The characterization result of bio-oil product are density is 1.008 gr/ml, viscosity is 12.63 cp, flash point 490 C, and maximum of component obtained is acetic acid with 47.09%.
Pengaruh Jenis dan Konsentrasi Aditif Terhadap Karakteristik Faktis Coklat dari Minyak Jarak Pagar Santi Puspitasari
Eksergi Vol 11, No 1
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v11i1.331

Abstract

Processing aid is an important chemical which is added to the rubber compound preparation. This ingredient will facilitate rubber mixing with other rubber chemicals. Brown factice is a processing aid used in the rubber article industries, especially in the rubber hose manufacture. This material is synthesized by polymerization of vegetable oil with sulfur at certain temperature. This reaction produces a crosslinking of the triglyseride molecules connected by sulfur. The crosslink causes the brown factice texture become elastic or rubberlike. The condition of the polymerization reaction and the compotition of reactant affect the brownfactice quality. The classification of brown factice is based on its visual and chemical  properties. The aim of the research was to study brown factice formulation which produce the optimum polymerization condition and the best quality of brown factice. In this experiment the brown factice was synthesized from Jatropha curcas oil at the laboratory scale using TMTD and ZDEC accelerators, by 1.0 pho dosage. The polymerization was conducted at 140oC on 30.0 pho of sulphur, while the ZnO and Na2CO3 dosage was varied at 0.25 and 0.50 pho. The reaction time, temperature, and exothermic step were observed conscientiously during the reaction. The brown factice rendemen was calculated and its quality was characterized. The result showed that the condition of the polymerization reaction using ZDEC and TMTD as  accelerator was not significantly different, but the quality of brown factice using ZDEC was better than TMTD (brighter color, lower free sulphur content, and acetone extract content). The best quality of  brown factice was obtained from the formulation of ZDEC as accelerator, 0.5 pho of ZnO and 0.5 pho of Na2CO3. 
Pengaruh Penambahan Aditif Proses Daur Ulang Minyak Pelumas Bekas terhadap Sifat-sifat Fisis Siswanti Siswanti
Eksergi Vol 10, No 2 (2010): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v10i2.336

Abstract

Peningkatan jumlah kendaraan bermotor dan industri menyebabkan pemakaian minyak pelumas meningkat, akibatnya jumlah minyak pelumas bekas semakin meningkat. Hal ini jika dibiarkan dapat menyebabkan pencemaran lingkungan. Sehingga dengan memanfaatkan kembali minyak pelumas bekas dapat mengurangi pencemaran lingkungan dan mengurangi konsumsi minyak bumi. Salah satu cara pengolahan minyak pelumas bekas adalah dengan proses daur ulang. Minyak pelumas bekas hasil daur ulang memiliki mutu yang kurang baik, sehingga perlu ditingkatkan mutunya dengan menambahkan zat aditif. Proses daur ulang dilakukan dengan cara menghilangkan zat pengotor yang terkandung dalam minyak pelumas bekas menggunakan asam sulfat pekat kemudian ducuci dengan larutan deterjen dan ditambah CaCl2 sebagai pemecah emulsi. Selanjutnya untuk meningkatkan mutunya ditambah dengan aditif yaitu nitrobenzen dan phenol dengan perbandingan 1 :1 pada suhu 70 oC. Kondisi terbaik yang diperoleh dalam penelitian ini adalah perbandingan aditif dengan minyak pelumas hasil daur ulang 1,5 :1 untuk waktu pemakaian di dalam mesin gergaji kayu selama 6 jam.
Produksi Biodisel dari Minyak Jelantah Menggunakan Katalis Asam padat (Nafion/SiO2) Mahreni Mahreni
Eksergi Vol 10, No 2 (2010): Versi Cetak
Publisher : Prodi Teknik Kimia, Fakultas Teknologi Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v10i2.341

Abstract

Production of biodisel from waste cooking oil (WCO) was performed using a double catalyst Nafion/SiO2 as esterification catalyst and NaOH is used as transesterification catalyst . Study was conducted through three stages:as well as  synthesis of Nafion/SiO2 solid acid catalyst, the synthesis of biodisel using a single catalyst (NaOH) and the synthesis of biodisel using a catalyst (Nafion/SiO2 and NaOH). Solid acid catalyst is made of Nafion 5 wt.% solution and the (Tetra Ethoxy Ortho silicate, TEOS) using solution phase sol-gel method to produce Nafion/SiO2. Furthermore Nafion/SiO2 was applied as esterification catalyst. Esterification reaction conditions at temperatures of 75oC and fixed reaction time of 45 minutes. The reaction is run at three-neck flask equipped with a stirrer, thermometer and cooling water. Products are separated and the upper layer is used as a reactant of transesterification reaction using NaOH catalyst and results biodisel (FAME). Result analysis of physical properties, ie viscosity, density and flash point FAME meets the standard requirements of biodisel. Chemical characterization in the FAME show there are more than six kinds of methyl esters indicate that FAME was formed. The percentage of biodisel that is produced by using dual catalyst is higher compared to using a single catalyst proved that the solid acid catalyst plays an important role in converting the free fatty acid in to ester in the WCO.

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