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Equilibrium Journal of Chemical Engineering
Published by Universitas Sebelas Maret
ISSN : -     EISSN : 26223430     DOI : https://dx.doi.org/10.20961/equilibrium.v4i1.42852
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Engineering Materials Science & Nanotechnology
Equilibrium Journal of Chemical Engineering (EJChE) publishes communication articles, original research articles and review articles in :. Material Development Biochemical Process Exploration and Optimization Chemical Education Chemical Reaction Kinetics and Catalysis Designing, Modeling, and Process Optimization Energy and Conversion Technology Thermodynamics Process System Engineering and products Membrane Technology Food Technology Bioprocess Technology Chemurgy Technology Waste Treatment Technology Separation and Purification Technology Natural Dyes Technology
Arjuna Subject : Teknik Kimia (semua kategori) - Kimia Proses dan Teknologi
Articles 99 Documents
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Microencapsulation of Riboflavin (Vitamine B2) using Alginate and Chitosan : Effect of Surfactant Span 80 upon Microcapsule Diameter YC. Danarto; Rochmadi Rochmadi; Budhijanto Budhijanto
Equilibrium Journal of Chemical Engineering Vol 2, No 2 (2018): Volume 2 No 2 July 2018
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v2i2.40434

Abstract

Riboflavin (vitamin B2) plays an important role in the growth and maintenance of human metabolism. Riboflavin is the highly sensitive and unstable to environmental influences such as light, reducing agents and pH. Riboflavin is protected by forming it into microcapsules with sodium alginate as a matrix and coated with chitosan reinforced with glutraldehid crosslinking. This study aims to study the process of microencapsulation of riboflavin with sodium alginate and chitosan and is emphasized to study the effect surfactant span 80 upon the size of the microcapsules formed. Based on microcapsule size and its distribution,  it  can  be  concluded  that  more  span  80  added  to  paraffin  oil  will  reduce  the  size  of microcapsule that is formed
Pengaruh Perendaman Asam Nitrat pada Pemrosesan Nasi Instan untuk Menurunkan Indeks Glikemik Joko Waluyo; Yusi Prasetyaningsih; Fenny Tri Ariyani; Ida Maya Sari
Equilibrium Journal of Chemical Engineering Vol 4, No 1 (2020): Volume 4 No 1 July 2020
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v4i1.43225

Abstract

Abstrak. Nasi merupakan makanan utama bagi kebanyakan orang di Indonesia. Memasak nasi membutuhkan waktu sekitar 40-50 menit. Nasi instan merupakan solusi untuk menanak nasi dalam waktu yang relatif singkat melalui proses precooking dan pengeringan. Tujuan penelitian ini adalah membuat nasi instan dengan indeks glikemik rendah agar dapat dikonsumsi oleh penderita diabetes melitus. Cara pembuatan nasi instan ini adalah dengan cara merendam - memasak - membekukan - mengeringkannya. Beras direndam menggunakan larutan Na-sitrat 2 - 7% pada suhu 50°C, selama 2 jam. Perbandingan beras dengan larutan perendaman adalah 1: 2. Nasi yang sudah dimasak dibekukan di dalam freezer pada suhu -4°C selama 24 jam. Beras yang telah dicairkan dengan proses thawing menggunakan air hangat pada suhu 60°C. Beras kemudian dipanaskan pada suhu 70°C selama 4-5 jam. Nasi instan siap diseduh (dihidrasi kembali) menggunakan air mendidih. Waktu rehidrasi beras instan mencapai 5,49 menit. Hasil pengujian indeks glikemik menunjukkan nilai indeks glikemik instan sebesar 51,69 dengan kandungan nutrisi yang tidak berubah secara signifikan seperti beras asli. Hasil penelitian menunjukkan bahwa pembuatan nasi instan dengan perendaman-masak beku-kering dapat menurunkan indeks glikemik. Abstract. Rice is the main food for most people in Indonesia. Cooking rice takes about 40-50 minutes. Instant rice is a solution for cooking rice in a relatively short time through a process of precooking and drying. The purpose of this study is to make instant rice with a low glycemic index so that it can be consumed by people with diabetes mellitus. The method used in making this instant rice is soak - cook - freeze - dry it. The rice is soaked using 2 - 7% Na-citrate solution at 50°C, for 2 hours. The ratio of rice with a soaking solution is 1: 2. Rice is needed up to pH 7 then accepted using ricecookerz. Cooked rice is frozen in the freezer at -4°C for 24 hours. Rice which has been liquefied by thawing process uses warm water at 60°C. Rice is then heated at 70°C for 4-5 hours. Instant rice is ready to be brewed (rehydrated) using boiling water. Instant rice rehydration time reaches 5.49 minutes. The glycemic index test results showed an instant glycemic index value of 51.69 with a nutrient content that did not change significantly like the original rice. The results show that making instant rice vy soaking-cookingfreezing -drying can reduce the glycemic index. Keywords: quick cooking rice, rehydration time, glycemic index
Kinetika Reaksi Sintesis Karboksi Metil Glukomanan Rahmawati Andayani; Santi Tri Wijayanti; Fadilah fadilah
Equilibrium Journal of Chemical Engineering Vol 1, No 1 (2017): Volume 1 No 1 January 2017
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v1i1.40068

Abstract

Cultivation of porang plants now has a promising prospect because it has a higheconomic value. Glucomannan content in porang is quite high (15-64% dry base).Glucomannan, the natural polymers contained in porang corms, can be modified bycarboxymethylation. The synthesis of carboxy methyl glucomannan took place over twosteps, alkalization and carboxymethylation. Alkalization was conduct using NaOH inethanol 70% as the medium. The carboxymethylation steps was conducted by addingsodium chloroacetate as the reagent. The quality of carboxy methyl glucomannan wasdetermined from its Degree of Substitution (DS). The results showed that the highestdegree of substitution was 0.47 with 70% ethanol as medium and at temperature 65oC for 150 minutes reaction time. From the data obtained, it can be seen that the reaction ofglucomannan carboxymethylation proceeded at 1st order reaction, with the collision factorvalue (A) of 491.227 J/mol.K and its activation energy (Ea) of 30,994.59 J/mol.K.
Review : Metode Sintesis Katoda LiFePO4 Baterai Lithium-Ion Moch Khabibul Adi Rachmanto; Liliana Triatmajaning Wibowo; Tika Paramitha
Equilibrium Journal of Chemical Engineering Vol 3, No 2 (2019): Volume 3 No 2 December 2019
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v3i2.42833

Abstract

Abstrak. Material katoda merupakan salah satu komponen penting pada baterai berbasis lithium-ion. Material katoda yang digunakan dalam baterai lithium-ion diantaranya LNCA (LiNi0,8Co0,15Al0,05O2), LiCoO2, LiMn2O4, LiFePO4, dan LNCM (LiNi0,3Co0,3Mn0,3O2). Katoda LiFePO4 yang memiliki keunggulan beda tegangan operasi yang tinggi (3,45 V phosphoolivines), kapasitas spesifik tinggi (170 mAh/g), biaya bahan baku murah, ramah lingkungan, kestabilan terhadap panas tinggi, dan dapat diaplikasikan sebagai penyimpanan daya tinggi. Namun, LiFePO4 juga memiliki beberapa kelemahan yaitu memiliki konduktivitas rendah, laju difusi ion Li+ yang lambat, dan kerapatan energi yang rendah. Untuk mengoptimalkan kekurangan tersebut, telah dilakukan sintesis katoda dengan berbagai metode. Artikel ilmiah ini membahas mengenai sintesis katoda LiFePO4 dengan beberapa metode, yaitu presipitasi, solid state, dan sol gel. Selain itu, artikel ini memuat tinjauan (review) mengenai hasil analisa struktur, morfologi, dan performa elektrokimia baterai dengan katoda LiFePO4. Abstract. Cathode material is one of important component in lithium ion batteries. Cathode materials used in lithium ion batteries including LNCA (LiNi0,8Co0,15Al0,05O2), LiCoO2, LiMn2O4, LiFePO4, and LNCM (LiNi0,3Co0,3Mn0,3O2). The advantage of LiFePO4 cathode are high operating voltage (3.45 V phosphoolivines), high specific capacity (170 mAh/g), low cost raw material, environmentally friendly, high heat stability, and can be applied as high power storage. However, LiFePO4 also has disadvantages, such as low conductivity, slow diffusion rate of Li+ ions, and low energy density. To optimize these deficiencies, cathode synthesis has been carried out with various methods. This scientific article discusses the synthesis of the LiFePO4 cathode with several methods, namely precipitation, solid state, and sol gel. In addition, this article discuss about review of the structural analysis, morphology, and electrochemical performance of LiFePO4 cathode batteries. Keywords: LiFePO4, cathode, synthesis, lithium ion batteries
Performance Test of Starch-g-Polyacrylamide Synthesized through Grafting as a Flocculant in Artificial Wastewater Treatment Mujtahid Kaavessina; Ina Fatimah; Suci Soraya
Equilibrium Journal of Chemical Engineering Vol 2, No 1 (2018): Volume 2 No 1 January 2018
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v2i1.40429

Abstract

Flocculation is one of the steps to get clean water. Grafted flocculant was successfully synthesized by combining the benefits of synthetic polymers (polyacrylamide) and natural polymers (cassava starch). This synthesis used “grafting to” method and passed through two stages, i.e. (i) the synthesis of non-terminated polyacrylamide (nt-PAM) and followed by (ii) grafting of non-terminated polyacrylamide (nt-PAM) on the cassava starch. The obtained flocculants were analyzed their molecular structure to determine the success of grafting. Fourier Transform Infra-Red (FTIR) spectra were verifying that polyacrylamide can be attached in the starch molecules. Both neat starch and modified starch were studied as a backbone. The molecular weight of the flocculant is increasing as the increase of acrylamide concentration and polymerization time. The effectiveness of flocculation is relating with the molecular weight. However, the longer chains of attached polyacrylamide show better performance during flocculation than that of shorter chains although the molecular weight was same. The best performance was showed for the flocculant that using: (i) modified starch of cassava as a backbone, (ii) acrylamide concentration of 0.02 M and (iii) polymerization time of 90 minutes. As monitored, it could reduce the turbidity of artificial wastewater about 87,81 %
Pirolisis Sampah Plastik HDPE sebagai Alternatif Pengganti Kerosin dengan Menggunakan Katalis Zeolit Alam Joko Waluyo; Aji Putra Perkasa; Devaliandra Ramadhana
Equilibrium Journal of Chemical Engineering Vol 3, No 1 (2019): Volume 3 No 1 July 2019
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v3i1.43101

Abstract

Abstrak. Untuk mengurangi jumlah sampah plastik di Indonesia dapat dilakukan dengan berbagai metode salah satunya adalah dengan pirolisis. Metode pirolisis digunakan untuk mengubah sampah plastik menjadi fuel oil. Maka dari itu dilakukan uji coba penelitian pembuatan fuel oil dengan metode pirolisis dari plastik HDPE yang merupakan jenis plastik yang sering digunakan oleh masyarakat Indonesia Penelitian ini juga menggunakan batu zeolite alam sebagai katalis. Batu zeolite alam sebelumnya dipanaskan pada suhu 400oC selama 4 jam untuk menghilangkan uap air dan kotoran yang ada. Dari percobaan didapatkan 4 sampel dengan kondisi berbeda-beda yaitu sampel A menggunakan katalis dengan suhu pemanasn maksimal 400oC serta besarnya heating rate 2,5oC/menit, sampel B menggunakan katali dengan suhu pemanasan maksimal 350oC serta besarnya heating rate 3,9oC/menit, sampel C tidak menggunakan katalis dengan suhu pemanasannya maksimal 400oC serta besarnya heating rate 3,3oC/menit, sampel D tidak menggunakan katalis dengan suhu pemanasan maksimal 350oC serta besarnya heating rate 3,3oC/menit. Besarnya yield minyak yang dihasilkam adalah 41,25 %, 32,29%, 40,9%, dan 13,9 %. Untuk densitas adalah 0,762 gram/ml, 0,747 gram/ml, 0,769 gram/ml, dan 0,766 gram/ml dan untuk viskositas adalah 0,0071 poise, 0,0084 poise, 0,0104 poise, dan 0,0096 poise. Abstract. Pyrolysis is a method to reduce plastic waste and convert it into liquid fuel. The aim of this research is to study the effect of zeolite catalyst on the pyrolysis of HDPE plastics. Previously, natural zeolite was heated at 400°C for 4 hours to remove moisture and impurities. From the experiment, 4 samples were obtained with different conditions, namely Sample A was the result of pyrolysis with a catalyst at 400°C and a heating rate of 2.5°C/minute, Sample B was the result of pyrolysis with a catalyst at 350°C and a heating rate of 3.9°C/minute. Sample C was the result of pyrolysis without a catalyst at 400°C and the heating rate was 3.3°C/minute, Sample D was the result of pyrolysis without a catalyst at 350°C and the heating rate was 3.3C/minute. The resulting oil yields from sample A to D were 41.25%, 32.29%, 40.9%, and 13.9%, respectively. The density was 0.762 gram/ml, 0.747 gram/ml, 0.769 gram/ml, and 0.766 gram/ml and for viscosity was 0.0071 poise, 0.0084 poise, 0.0104 poise, and 0.0096 poise, respectively. The analysis results show that pyrolysis at 350°C with zeolite catalyst will produce gasoline, whereas without catalyst it will produce kerosene oil. Keywords: pyrolysis, fuel oil, HDPE, zeolite, catalyst
Karakteristik Bioplastik Kitosan-Onggok Aren (Arenga pinnata) dengan Penambahan Serbuk Kunyit Suwardi Suwardi; Nur Hidayati
Equilibrium Journal of Chemical Engineering Vol 4, No 2 (2020): Volume 4 No 2 December 2020
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v4i2.47911

Abstract

Abstrak. Bioplastik merupakan plastik organik yang salah satu fungsinya dapat digunakan sebagai pengemas bahan pangan. Bioplastik dikenal ramah lingkungan karena mudah terdegrasi oleh alam. Kitosan dapat dimodifikasi dengan pati onggok aren dalam pembuatan bioplastik untuk meningkatkan kekuatan bioplastik. Penambahan kunyit ke dalam bioplastik kitosan-serat onggok diharapkan dapat meningkatkan ketahanan terhadap mikroba sehingga bioplastic tersebut dapat digunakan sebagai bahan kemasan makanan.  Penelitian ini bertujuan untuk mengetahui karakteristik bioplastik kitosan-onggok aren yang ditambah kunyit dengan variasi 0,3- 1,2 %. Uji fisik yang dilakukan meliputi uji daya serap air, uji kuat tarik, uji elongisitas dan uji biodegradasi. Peningkatan banyaknya kunyit dalam air meningkatkan sifat daya serap air, kuat tarik dan biodegradasinya, sedangkan penurunan kemuluran plastik berkurang dengan peningkatan banyaknya kunyit dalam plastik.Abstract. Bioplastics are organic plastics which one of their functions can be used as food packaging. Bioplastics are known to be environmentally friendly because they are easily degraded by nature. Chitosan can be modified with onggok palm starch in making bioplastics to increase the strength of the bioplastics. The addition of turmeric to the chitosan-onggok bioplastic is expected to increase resistance to microbes so that the bioplastic can be used as a food packaging material. This study aims to determine the bioplastic characteristics of chitosan-onggok palm sugar added with turmeric with a variation of 0.3-1.2%. Physical tests carried out include water absorption test, tensile strength test, elongicity test and biodegradation test. The increase in the amount of turmeric in water increases its water absorption, tensile strength and biodegradation properties, while the decrease in plastic elongation decreases with the increase in the amount of turmeric in the plastic.
Kinetika Slow Release Pupuk Urea Berlapis Chitosan Termodifikasi YC Danarto; Anggita Nugrahey; Sela Murni Noviani
Equilibrium Journal of Chemical Engineering Vol 1, No 2 (2017): Volume 1 No 2 July 2017
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v1i2.40422

Abstract

During this time, the use of urea is not efficient, because about 40-70% of nitrogen in the fertilizer is not absorbed by plants. In order to increase the effectivity of nitrogen release in urea fertilizer, it needs to be coated with modified chitosan as slow releasing agent to form a hydrogel material by forming a cross linking with glutaraldehyde cross-linker.The aims of this research is to study the mechanism and the appropriate kinetic model of nitrogen release in slow releasing fertilizer of modified chitosan. This research was conducted by analyzing the ability of bio-hydrogel by calculating the percentage of swelling ratio and water retention of hydrogel and the nitrogen release in slow releasing fertilizer both in the soil and water. The experiments were conducted by varying the amount of urea used which  30 gram, 40 gram, 50 gram, 60 gram and 70 gram of urea fertilizer. The The release profile is then plotted on several models of diffusion kinetic such as zero order, first order, higuchi and korsmeyer peppas. The appropriate model of diffusion kinetic is chosen by the largest correction factor (R2).The results showed that nitrogen release of the slow releasing fertilizer in the soil with 50% urea content  and  the  water  followed  korsmeyer  peppas  model  with  fickian  mechanism. Nitrogen release in the soil with urea content of 30%, 40%, 60%, and 70% followed the korsmeyer peppas model with nonfickian mechanism.
Optimization of Cow’s Milk Processing into Milk Soap Bar on Small-Medium-Micro Enterprises (UMKM) Ari Diana Susanti; Sulistyo Saputro; Wusana Agung Wibowo
Equilibrium Journal of Chemical Engineering Vol 2, No 2 (2018): Volume 2 No 2 July 2018
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v2i2.40435

Abstract

The quality and quantity of cow’s milk produced were determined by the genetic, food, age, milking processing, and the treatment of cattle. The storability of fresh cow's milk tends to be short. Therefore, it is necessary to find ways to extend the life time of fresh cow's milk, one of which is by processing fresh cow's milk into other products, such as milk soap bar. The purpose of this study was to determine the appropriate method of milk soap bar production in home industries capacity and to formulate composition of vegetable oils and fresh cow's milk. The milk soap bar obtained then was analyzed in several laboratory tests such as acidity test (pH), moisture content, free alkaline content, and foam stability. Based on the research, it is turned out that the appropriate method of milk soap bar production was the cold process. The optimum formula is olive oil (11%), coconut oil (22%), palm oil (22%), fresh cow's milk (33%), and NaOH pellets (12% - equivalent to 9.2 N). The free alkaline content will decrease according the curing time. Simpler economic evaluation obtained that the production cost of milk was Rp.6,711.22/package of 80 grams of milk soap bar. Milk soap bar  is sold for Rp. 7,000.00 will provide 87.96% after-tax of ROI, 11.7– month of POT, and 65.31% of BEP.
Two Step and Direct Fermentation in the Production of Ethanol from Starch: A Short Review Endah Retno Dyartanti; Margono Margono; Anisa Raditya Nurohmah; Shofirul Sholikhatun Nisa; Novan Riantosa
Equilibrium Journal of Chemical Engineering Vol 4, No 1 (2020): Volume 4 No 1 July 2020
Publisher : Program studi Teknik Kimia UNS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/equilibrium.v4i1.46130

Abstract

Abstract.  Ethanol as a renewable fuel has been widely produced in various countries. One source of raw material for producing ethanol is starch. The process of producing ethanol from starch needs to be pretreated so that starch molecules can split into smaller ones. However, this process requires pre-treatment which will expensive more than ethanol from sugar. There are two types of pretreatment i.e. two-step ethanol production and direct fermentation. There is two kind of hydrolysis, acid hydrolysis, and enzymatic hydrolysis. Two-step ethanol production is a conventional method that separates pretreatment and fermentation process, while direct fermentation is the direct production of starch into ethanol using recombinant yeast that co-produces enzymes such as amylose and glucoamylase. Two-step ethanol production has the advantage of high yield but needs high cost whereas, direct fermentation has the advantage of low-cost production but needs longer time. Common starch to ethanol production consists of two stages, namely hydrolysis of raw materials into glucose and fermentation into ethanol. Both of these processes can be run on average at temperatures of 30-80oC with a pH range of 4-6 and varying time intervals. The enzyme used depends on the source of the starch, but the most commonly used is Saccharomyces cerevisiae.Keywords: Ethanol, starch, pre-treatment

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