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Jurnal Rekayasa Proses
Published by Universitas Gadjah Mada
ISSN : 1978287X     EISSN : 25491490     DOI : -
Core Subject : Education, Social,
Education Social Sciences
Jurnal Rekayasa Proses (J. Rek. Pros) is an open-access journal published by Chemical Engineering Department, Faculty of Engineering, Universitas Gadjah Mada as scientific journal to accommodate current topics related to chemical and biochemical process exploration and optimization which covers multi scale analysis from micro to macro and full plant size.
Arjuna Subject : -
Articles 217 Documents
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Coconut husk to reducing sugar conversion using combined ultrasound and surfactant aided subcritical water Saiyyidah Tus Zuhroh; Akbarningrum Fatmawati; Arief Widjaja
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.69231

Abstract

The first purpose of this study was to investigate the effect of operating variables and surfactant concentration in subcritical water to after ultrasonic process on the sugar-producing yield from coconut husk. The second purpose was to obtain the optimum operating condition of the subcritical water process. The sonication before the subcritical water process was done by dispersing 40 mesh coconut husk powder in water at  60°C,  and  35  kHz. The effect of sonication time was studied by comparing the material crystallinity and composition after being treated for 30 minutes. In this research, the optimization was done by using a Box-Behnken response surface methodology (RSM) experimental design with 3 factors (temperature, time, and surfactant concentration). The designed lower and upper levels were 130°C and 170°C, 40, and 80 minutes, as well as 1 and 3% (w). The results showed that the quadratic response surface model predicted the maximum reducing sugar yield to be 12.0%, which was achieved at the optimum condition of 170°C, 77.5 minutes, and 2.3% SDS surfactant addition. The experiment run at the obtained optimum condition resulted in a reducing sugar yield of 11.7%, which was close to that obtained from the model prediction.
Effect of salt concentration on the properties of electrolyzed reducing water (ERW) and electrolyzed oxidizing water (EOW): an empirical correlation study Laras Prasakti; Billy Dion Yogihaz; Lukman Subekti; Anton Sujarwo; Agus Prasetya
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.69673

Abstract

This research aimed to examine the effect of NaCl concentration on the pH and Oxidation Reduction Potential (ORP) values of both EOW and ERW products. The experiment was conducted using distilled water. The electrolysis apparatus consisted of anode and cathode chambers. The chambers were connected by a tube filled with a cotton (or a fabric). Both electrodes (anode and cathode) were made of titanium and formed as a spiral. Electrolysis was performed for 780 minutes, and the pH and ORP values of both EOW and ERW were measured every time. Sodium chloride concentration was varied for 0, 100, and 200 ppm. Experimental results revealed that the higher the NaCl concentration, the higher ERW’s pH rise and the lower the EOW’s pH. Similar results were found for ORP. ERW’s ORP was lowered while EOW’s ORP rose with the increase in NaCl concentration. This study could also generate a mathematical model that correlates pH and time during the electrolysis process. The model was developed by connecting with a simple polynomial. A similar approach was used to develop the model that correlates pH and ORP value.
Study of chromium removal from wastewater using SSF-CW model: comparison between physical adsorption by coal CFA and phytoremediation by vetiver grass (Vetiveria Zizanioides L) Titik Indrawati; Sarto Sarto; Agus Prasetya
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.69978

Abstract

The study aims to compare the effectiveness of chromium removal from water using adsorption by coal fly ash (CFA) and phytoremediation by vetiver grass (Vetiveria zizanioides L) as well as a combination of both CFA and vetiver grass. The experiment was carried out in four different reactors, having size of 100 cm (length) x 60 cm (wide) x 80 cm (height). One reactor was filled with gravel and CFA, without vetiver grass (RI), while another one was filled with gravel and vetiver grass, without CFA (RIV). The other two reactors were filled with gravel, CFA, and vetiver grass with the mass ratio of gravel/CFA of (25:2) and (25:1), denoted as RII and RIII, respectively. Fifty (50) L of synthetic wastewater containing 14.612 ppm of chromium was filled into the reactors and continuously recirculated for 15 days. Chromium accumulation in CFA and plants was analyzed on day 15. The results of plant development are indicated by the presence of new shoots and roots that grow during phytoremediation processes. In addition, there was an increase in weight and number of vetiver stems indicating the persistency of vetiver grass in such a harsh wastewater condition. The removal of Cr from wastewater in RI, RII, RIII and RIV at days 15 were 81%, 93.2%, 85.8% and 75.7%, respectively. It can be concluded that: (1) vetiver grass (Vetiveria zizanioides L) has high potential as phytoremediator plant, (2) Chromium adsorption by CFA plays important role in Cr removal from wastewater, and (3) combination of adsorption by CFA and a phytoremediation by vetiver grass significantly increases the removal of chromium from wastewater.
Analisis perubahan sistem kualitas udara Kota Yogyakarta pada masa pandemi COVID-19 Himawan Novianto; Muhammad Mufti Azis; Hilya Mudrika Arini
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.71888

Abstract

Beberapa penelitian membahas penurunan konsentrasi polutan udara selama masa pandemi COVID-19, namun belum banyak penelitian yang membahas kaitan antara variabel kualitas udara dan tingkat mobilitas masyarakat. Penelitian ini menyelidiki keterkaitan hubungan antara variabel polutan udara, faktor meteorologi, dan tingkat mobilitas masyarakat di Kota Yogyakarta. Fenomena hubungan sistem kualitas udara dan mobilitas masa pandemi COVID-19 tahun 2020 terbagi dalam dua periode: (a) Pembatasan Aktivitas (April s.d. Juli 2020) dan (b) Normal Baru (Agustus s.d. Desember 2020). Kualitas udara Kota Yogyakarta sebelum dan pada masa pandemi COVID-19 menunjukkan perbaikan, dari kategori Baik: 31,85% menjadi 90,37% ISPU (chi-square asymp.  sig.  < 0,05).   Polutan udara PM10, SO2, dan CO menurun sebesar 18%, 93%, dan 74%, sedangkan O3 meningkat sebesar 104% pada masa pandemi COVID-19 tahun 2020. Polutan udara primer PM10, SO2, dan CO berhubungan positif terhadap faktor meteorologi penyinaran matahari, tetapi berhubungan negatif terhadap polutan udara sekunder O3 serta faktor meteorologi suhu udara, kelembaban udara, curah hujan, dan kecepatan angin. Pembatasan aktivitas masyarakat di luar rumah secara umum menyebabkan perbaikan kualitas udara, di mana penurunan mobilitas transportasi menjadi variabel yang mempengaruhi penurunan polutan udara primer di Kota Yogyakarta. Pembatasan aktivitas mempengaruhi polutan udara sekunder, di mana kenaikan O3 terjadi ketika mobilitas dalam ruangan dan transportasi meningkat.
Isolasi mikroalga Aurantiochytrium dari Raja Ampat dan potensinya pada industri bahan baku adjuvant vaksin Suhendra Suhendra; Lia Septianingsih; Tifanny Rizka Ariandi; Maratul Husna; Zen Adi Laksana; Dewi Yuniasih; Andri Hutari
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.72045

Abstract

Tulisan ini bertujuan memberikan kontribusi akademis potensi mikroalga Aurantiochytrium dari hutan bakau Indonesia. Tulisan ini mempresentasikan gambaran awal penelitian tentang mikroalga Aurantiochytrium mulai dari teknik isolasi mikroalga dari habitatnya, gambaran produksinya, teknik analisa kualitatif squalene hingga analisa potensi ekonomi dan fungsinya untuk bahan baku adjuvant vaksin. Sebanyak 10 sampel daun bakau diambil dari hutan bakau Raja Ampat, Papua Barat. Teknik isolasi menggunakan metode direct plating method. Setelah aplikasi teknik streaking dari koloni mikroalga yang ada pada sampel ke dalam medium agar, dihasilkan 4 isolat murni.  Produksi awal biomassa berbahan baku mikroalga Aurantiochytrium ditampikan dengan nutrisi glucosa, yeast extract, peptone dan campuran air laut dan aquadest. Analisa kualitatif produk yang dihasilkan menggunakan Kromatografi Lapis Tipis (KLT) menunjukkan hasil positif adanya sqalene pada biomassa hasil kultivasi isolat mikroalga Aurantiochytrium. Squalene dari hasil fermentasi mikroalga Aurantiochytrium telah banyak dikaji sebagai sumber bahan baku alternatif yang ramah lingkungan dan berkelanjutan (sustainable), Beberapa adjuvant vaksin, termasuk vaksin covid-19 menggunakan bahan baku mikroalga Aurantiochytrium untuk menggantikan adjuvant vaksin yang bersumber dari ikan hiu laut dalam. Di masa depan, potensi produk mikroalga Aurantiochytrium akan semakin dibutuhkan di banyak industri nutrisi kesehatan dan kosmetik. Mengingat relevansinya untuk masa depan industri strategis terkait di Indonesia, seyogyanya perlu riset mendalam yang lebih banyak dari isolat mikroalga Aurantiochytrium dari hutan bakau Indonesia.
Microwave assisted extraction of anthocyanin from purple sweet potato (Ipomoea batatas L.) using deep eutectic solvent (DES) based on citric acid Rachma Tia Evitasari; Hana Rofiqoh; Putri Alfina Damayanti; Firda Mahira Alfiata Chusna
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.72046

Abstract

Purple sweet potato (Ipomoea batatas L.) is one of the tubers or roots that is widely grown in Indonesia that contain high antioxidants. One type of flavonoid that functions as an antioxidant is a natural dye called anthocyanin. In the process of extraction of anthocyanin, the solvent has an important role. In this research, the deep eutectic solvent was used because it is more economical and environmentally friendly. This research will optimize the microwave assisted extraction of anthocyanin content in purple sweet potato (Ipomoea batatas L.) using a deep eutectic solvent with the variation of material to solvent ratio, microwave power, and extraction time. Optimization is done by using the statistical method Response Surface Method (RSM) with Total Anthocyanin content as a response. The optimum operating conditions for the extraction of anthocyanins from purple sweet potato using the deep eutectic solvent were obtained at a solid to solvent ratio of 1:29 at a microwave power of 270 watts for 193 s, with an optimum TAC value of 311.64 mg/L and an antioxidant value of 44.85%. The use of DES can increase the extraction yield and is environmentally friendly.
Optimasi proses adsorpsi zat warna indigosol di air limbah artifisial menggunakan response surface methodology dengan pendekatan desirability function Rifawany Grace Sitohang; Nina Juliana Roberta Turnip; Astiti Aditia
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.72318

Abstract

Industri tekstil di Indonesia tumbuh menjadi salah satu sektor penyumbang devisa ekspor non-migas. Proses pewarnaan di industri tekstil berfungsi untuk memberikan warna pada benang dan kain. Indigosol merupakan salah satu jenis zat warna yang banyak digunakan pada industri tekstil. Pewarna jenis indigosol sering digunakan karena menghasilkan warna yang cerah dan tidak mudah luntur. Tahap pewarnaan membutuhkan pengelolaan dan pengolahan limbah cair yang memadai karena umumnya digunakan zat warna sintetis yang mengandung senyawa organik, logam berat, dan senyawa berbahaya lainnya. Metode yang banyak digunakan dalam pengolahan limbah cair zat warna adalah adsorpsi menggunakan karbon aktif. Rancangan percobaan menggunakan Box-Behnken Design (BBD) dengan 3 variabel bebas yaitu panjang gelombang zat warna limbah artifisial, konsentrasi limbah artifisial, dan massa karbon aktif, yang masing-masing variabel memiliki tiga level input. Pengukuran konsentrasi larutan sebelum dan sesudah proses adsorpsi dilakukan dengan menggunakan spektrofotometer UV-Vis dan data pengukuran diolah menggunakan Ms. Excel untuk memperoleh persentase penjerapan zat warna pada limbah artifisial. Selanjutnya, proses optimasi dilakukan dengan response surface methodology (RSM) melalui pendekatan desirability function (DF) yang bertujuan untuk memperoleh optimasi proses adsorpsi pada limbah zat warna indigosol. Pengukuran absorbansi menghasilkan panjang gelombang optimum untuk masing-masing jenis warna indigosol kuning, merah, dan violet adalah 470, 515, dan 520 nm. Hasil optimasi menunjukkan bahwa titik optimum persentase penjerapan berada pada konsentrasi umpan limbah 58,0808 mg/L, massa karbon aktif 60 mg, dan panjang gelombang zat warna 502,3232 nm. Di sisi lain, pengolahan hasil percobaan menunjukkan persentase penjerapan sebesar 97,59% pada konsentrasi umpan limbah 50 mg/L, massa karbon aktif 60 mg, dan panjang gelombang zat warna 515 nm (indigosol merah). Hal ini menunjukkan bahwa massa karbon aktif dan konsentrasi umpan pada tempuhan memberikan respons yang diprediksi sesuai hasil optimasi. beda halnya dengan panjang gelombang dari zat warna, karena respons pada hasil optimasi yaitu 502,3232 nm tidaklah merupakan panjang gelombang optimal dari zat warna indigosol merah. Pada percobaan semua istilah interaksi antara faktor kualitatif dan kuantitatif dimasukkan, maka disimpulkan bahwa hubungan berbeda antara faktor kuantitatif dan respons yang dimodelkan untuk setiap tingkat faktor kualitatif. 
Bio-oil synthesis from Botryococcus braunii by microwave-assisted pyrolysis Edixon Daniel Ortiz; Arief Budiman; Rochim Bakti Cahyono
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.74241

Abstract

Microalgae have proven to be a promising resource in renewable energy search; Products such as bio-oils could contribute to the replacement of petroleum. The objective of this investigation is to determine the decomposition mechanism, obtain the kinetic reaction, as well as evaluate the potential to obtain microalgae bio-oil through microwave-assisted pyrolysis (MAP). MAP is a new thermochemical conversion from biomass to bio-oil that is faster, efficient, controllable, and flexible, compared to conventional pyrolysis, rapid pyrolysis, or instant pyrolysis. As raw material in this experiment, Indonesian microalgae, Botryococcus braunii was used. The investigation focused on the temperature effect (100-300 °C) and the residence time (10-30 min); a modified microwave oven was used with a power of 900 W. Hexane was used for the extraction of bio- oil. The bio-oil composition was measured with chromatography of mass spectrometry gas (GC-MS) and then this data was used to evaluate a kinetic model and calculate the constant kinetic reaction of the pyrolysis process. The results indicated that bio-oil production begins from 100 °C, however, temperatures between 200-250 °C favor the production of bio-oil, while temperatures above 250 °C and the long residence times prioritize the production of bio-gas. Regarding the kinetic evaluated, the reactions seem to show from third to sixth order with an activation energy (E) of around 30 kj/mol and a pre-exponential factor (ln A) of around 9 s-1. Based on GC-MS Analysis, the bio-oil contains short chain alkanes, cycloalkanes, organic acids as well as aromatic, phenol, benzene compounds. On the other hand, although small amounts of oil were achieved, the decomposition of biomass was up to 50% favoring gas production, these results indicate that MAP has potential in the obtaining of biofuels such as bio-gas and bio-oil.
Optimization of sustainable biodiesel production from waste cooking oil using heterogeneous alkali catalyst M Andrifar; Fadjar Goembira; Maria Ulfah; Rika Putri; Rati Yuliarningsih; Rizki Aziz
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.74373

Abstract

The increasing world population, rapid industrialization, urbanization, and economic growth have led to a continuous increase in the consumption of fossil fuels to meet the ever-increasing demand for energy. Continuous emissions from burning fossil fuels will create a need to find appropriate and sustainable substitutes for fossil fuels. Biodiesel is the right alternative solution for diesel engines because it is renewable, non-toxic, and environmentally friendly. Waste cooking oil (WCO) from the food, non-food, restaurant, and household sectors is produced on a large scale in every country and can contribute to environmental pollution if proper disposal systems are not applied. Instead of throwing it landfills Environmental pollution can be minimized by recycling WCO. This study evaluates the potential of using WCO to produce biodiesel using zeolite synthesized from fly ash as a heterogeneous alkali catalyst through a transesterification reaction. The reactor in this study used a 1,000 ml three-necked boiling flask equipped with a condenser, cooling tank, and pump. Stirring and heating during the process of biodiesel production using a magnetic stirrer and a hot plate. The thermometer is used to measure the reaction temperature. Optimization of biodiesel production from zeolite catalyst synthesized from fly ash based on variations in the ratio of methanol: oil (8:1; 10:1; 12:1; and 14:1), catalyst weight (1, 2, 3, and 4% weight), and temperature (45 oC, 55 oC, and 65oC). Zeolite from fly ash produces biodiesel with a yield of 91.67% with optimum operating conditions reaction time of 60 minutes, methanol oil ratio of 8:1, operating temperature 55oC, and the amount of catalyst 1% by weight. This experiment confirms the possibility of utilizing fly ash waste for the application of catalysts in biodiesel production.
Pengaruh kombinasi antara fotodegradasi dan H2O2 terhadap karakteristik mikroplastik dari limbah disposable face mask Feerzet Achmad; Devita Amelia; Arie Sabdi Sembiring; Novia Putri Ananda; Melbi Mahardika
Jurnal Rekayasa Proses Vol 16, No 2 (2022)
Publisher : Departemen Teknik Kimia Fakultas Teknik Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jrekpros.76141

Abstract

Penelitian ini dilakukan untuk mengetahui pengaruh lama iradiasi sinar UV dan penambahan H2O2 terhadap karakteristik mikroplastik limbah disposable face mask (DFM). DFM atau masker sekali pakai terbuat dari bahan polipropilen memiliki sifat hidrofobik yang tinggi sehingga proses degradasi tidak dapat berlangsung secara maksimal. Fotodegradasi UV dan penambahan H2O2 merupakan salah satu metode yang dapat digunakan untuk memodifikasi struktur kimia dari mikroplasatik dengan membentuk gugus fungsi aktif seperti gugus karbonil dan gugus hidroksil. Fotodegradasi sinar UV dilakukan dengan memvariasikan lama waktu iradiasi sinar UV yaitu 24; 36; 48; 60; 72 jam untuk sampel tanpa dan dengan penambahan H2O2 1% v/v. Hasil proses fotodegradasi dikarakterisasi berdasarkan kandungan dari sampel, yaitu perubahan struktur kimia yang dianalisa menggunakan Fourier Transform Infrared (FTIR), perubahan morfologi permukaan mikroplastik dianalisa menggunakan mikroskop binokuler dan persentase penurunan berat mikroplastik dianalisa menggunakan metode gravimetri. Penelitian ini didapatkan hasil terbaik fotodegradasi tanpa H2O2 terjadi pada waktu 36 jam dan hasil terbaik fotodegradasi dengan kombinasi penambahan H2O2 terjadi pada waktu 60 jam berdasarkan penurunan persen transmitansi terbesar gugus karbonil (C=O) yang dianalisis menggunakan FTIR sehingga terjadi penurunan hidrofobisitas pada DFM walaupun tidak siginifikan. Penambahan H2O2 1% v/v tidak memberikan pengaruh signifikan terhadap perubahan karakteristik sampel yang difotodegradasi yang dibuktikan dengan hasil analisis FTIR, perubahan struktur permukaan sampel DFM dan berat yang hilang dari sampel DFM setelah proses fotodegradasi. Berat yang hilang dari sampel setelah proses fotodegradasi sebesar 0,43% tanpa penambahan H2O2 dan 0,29% dengan penambahan H2O2 dengan waktu iradiasi selama 72 jam(α < 1%).

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