Jurnal Teknik Kimia Indonesia最新文献

{"title":"Pengaruh Radiasi Microwave dan Perlakuan Asam pada Batubara Peringkat Rendah terhadap Perolehan Biosolubilisasi Menggunakan Neurospora intermedia","authors":"Nendry Nurramdani Solihah, Dwiwahju Sasongko, E. Restiawaty","doi":"10.5614/JTKI.2020.19.1.3","DOIUrl":"https://doi.org/10.5614/JTKI.2020.19.1.3","url":null,"abstract":"Abstrak. Biosolubilisasi batubara peringkat rendahmerupakan teknologi yang menjanjikan untuk mendapatkan bahan bakar cair yang ramah lingkungan. Biosolubilisasi batubara peringkat rendah dapat dilakukan dengan menggunakan mikroorganisme seperti Neurospora intermedia yang mampu menghasilkan enzim-enzim pensolubilisasi. Mekanisme biosolubilisasibatubaraterjadikarenaadsorpsienzim-enzim tersebutkepermukaan partikel batubara, sehingga proses perlakuan awal batubara perlu dilakukan untuk memudahkan proses adsorpsi enzim.Penelitian ini dilakukan untuk mengkaji pengaruh perlakuan awal partikel batubara peringkat rendah terhadap struktur batubara dan perolehan biosolubilisasi. Pengaruh perlakuan awal tersebut dikaji dengan membandingkan biosolubilisasi menggunakan partikel batubara tanpa perlakuan awal (B1), perlakuan fisik dengan memberikan radiasi microwave 511 Watt selama 5 menit (B2), perlakuan kimiawi dengan merendam partikel batubara dalam HNO3 8 M selama 48 jam (B3), serta perlakuan kombinasi radiasi microwave selama 5 menit dan HNO3 dengan konsentrasi 2, 4, 6, dan 8 M selama 48 jam (B4, B5, B6, dan B7). Partikel batubara B1 memiliki rentang diameter mesopori sebesar 33,97 Å, sedangkan partikel batubara yang telah mengalami perlakuan awal mengalami peningkatan diameter pori namun masih dalam rentang mesopori. Luas permukaan persatuan massa dan volume pori yang tertinggi diperoleh dari perlakuan B3, masing-masing adalah 44,39 m2/g dan 0,09 cc/g. Hasil analisis proksimat dan ultimat menunjukkan bahwa perlakuan asam dapat mengurangi kandungan karbon terikat. Secara kualitatif dapat terlihat bahwa biosolubilisasi batubara B1, B2, B4, dan B5 tidak terjadi dengan baik, sehingga tidak terdapat cairan hitam sebagai hasil batubara yang tersolubilisasi, sedangkan biosolubilisasi batubara B3, B6, dan B7 menghasilkan cairan hitam sejak hari pertama. Secara kuantitatif, biosolubilisasi batubara peringkat rendah menggunakan perlakuan B3 menghasilkan konsentrasi asam humat dan persentase biosolubilisasi yang tertinggi, masing-masing yaitu 186,1 mmol/L dan 67,8%. Kata kunci: biosolubilisasi batubara, HNO3, Neurospora intermedia, radiasi microwave. Abstract. Effect of Microwave Radiation and Acid Treatment on Low Grade Coal on Biosolubilization Acquisition Using Neurospora intermedia. Bio-solubilization of low rank coal is a promising technology to obtain environmentally friendly liquid fuel. Bio-solubilization can be carried out using microorganism, such as Neurospora intermedia, which is capable to produce solubilizing enzymes. Mechanism of coal bio-solubilization occurs due to enzymes adsorption onto surface of coal, so that the low rank coal pre-treatment is needed to easy enzyme adsorption. This research examines the effects of low rank coal pre-treatment towards coal structure and bio-solubilization yields. The effects of the pre-treatment were studied by comparing the bio-solubilization using coal with the following specification: without treatment (B1), phy","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"270 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115075624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variasi Antioksidan dalam Pembuatan Protected Active Dried Yeast","authors":"Ronny Purwadi, Vita Wonoputri, F. Fitriana, Najwa Shufia Choliq","doi":"10.5614/JTKI.2020.19.1.1","DOIUrl":"https://doi.org/10.5614/JTKI.2020.19.1.1","url":null,"abstract":"Abstrak. Penggunaan antioksidan pada pembuatan protected active dried yeast (PADY) dapat memperpanjang umur simpan ragi kering. Antioksidan yang sering digunakan adalah antioksidan sintesis BHA dan BHT yang diduga bersifat karsinogenik. Penelitian ini bertujuan untuk mencari alternatif antioksidan yang lebih aman. Lima antioksidan yaitu asam sitrat, asam askorbat, tokoferol, natrium eritrobat, dan askorbil palmitat pada rentang konsentrasi 0,025-0,5% diuji pada suspensi ragiuntuk mempelajari efek inhibisi dari antioksidan tersebut. Uji laju produksi CO2 menunjukkan sifat noninhibisi dari asam askorbat, natrium eritorbat, asam sitrat, dan tokoferol, sedangkan sifat inhibisi askorbil palmitat dan BHT perlu diteliti lebih lanjut. Formulasi antioksidan terpilih untuk produksi PADY adalah asam sitrat 0,5%, asam askorbat 0,5%, dan tokoferol 0,5%. Pengeringan ragi dengan spray dryer menghasilkan PADY dengan kadar air sesuai standar. PADY dengan sifat fisik terbaik adalah variasi asam sitrat 0,5% dan asam askorbat 0,5% karena kelarutan dalam air yang baik serta granula yang lebih halus. Stabilitas vitalitas PADY diukur selama 45-50 hari, dan didapatkan PADY dengan antioksidan asam askorbat 0,5% memiliki konstanta laju kematian terendah, yaitu 0,0492/hari, setara dengan umur simpan 20 hari. Dengan demikian, formulasi antioksidan asam askorbat 0,5% berpotensi untuk dikembangkan pada produksi PADY. Kata kunci: antioksidan, ragi kering, stabilitas, vitalitas. Abstract. Variation of Antioxidant in Production of Protected Active Dried Yeast. The use of antioxidants in production of protected active dried yeast (PADY) can increase dried yeast’s shelf life. Usually, the antioxidants used are synthetic antioxidants such as BHA and BHT, which are known to be carcinogenic. Therefore, the aim of this research is to study antioxidant alternative that is safer. Five antioxidants, i.e. citric acid, ascorbic acid, tocopherol, sodium erythorbate, and ascorbyl palmitate in concentration range of 0.025-0.5% were tested on yeast suspension to study its inhibitory effect. CO2 production rate test showed noninhibitory characteristic of ascorbic acid, sodium erythorbate, citric acid, and tocopherol, whereas ascorbyl palmitate and BHT showed inhibitory characteristic. Formulations of antioxidants selected are 0.5% citric acid, 0.5% ascorbic acid, and 0.5% tocopherol. Spray drying of yeast resulted in PADY with moisture content within standard. PADYs with the best physical properties are 0.5% citric acid and 0.5% ascorbic acid variation due to good water solubility and finer granules. Vitality stability of PADY was measured for 45-50 days. PADY with 0.5% ascorbic acid had the lowest death rate constant, i.e. 0.0492/day, which is equivalent to 20-days shelf life. Thus, ascorbic acid antioxidant formulation of 0.5% can be developed in the production of PADY. Keywords: antioxidant, dried yeast, stability, vitality.","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125974107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tingkat Korosivitas Air Terhadap Infrastruktur Sumber Daya Air Berbahan Semen atau Mortar dengan fc’ ≤ 30 MPa pada 9 Waduk di Indonesia","authors":"D. Lestari","doi":"10.5614/JTKI.2020.19.1.4","DOIUrl":"https://doi.org/10.5614/JTKI.2020.19.1.4","url":null,"abstract":"Abstrak. Korosi atau kerusakan yang terjadi di infrastruktur sumber daya air terutama yang berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30 Mpa, dapat menimbulkan banyak kerugian. Kerugian yang ditimbulkan antara lain kerugian secara materiil karena korosi menggerogoti semua aset infrastruktur dan tentunya kerugian dalam hal keamanan karena dapat mengancam keselamatan manusia. Korosi merupakan permasalahan yang sangat penting dan tidak akan ada habisnya, karena peristiwa korosi terjadi secara terus-menerus dan berkelanjutan. Peristiwa korosi tidak dapat terjadi dengan sendirinya, tetapi karena adanya berbagai faktor-faktor tertentu yang dapat menyebabkan terjadinya korosi. Tujuan dari studi ini adalah untuk menentukan tingkat korosivitas air terhadap infrastruktur sumber daya air berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30 MPa pada 9 waduk di Indonesia, sehingga akan diketahui rekomendasi yang tepat untuk pencegahan dan pengendalian korosivitas air terhadap infrastruktur sumber daya air berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30 MPa, karena semen merupakan salah satu material yang paling banyak digunakan saat ini. Studi ini menggunakan data-data primer kualitas air. Metode pengambilan, penyimpanan, dan pengawetan sampel air dilakukan dengan mengikuti ketentuan dari Standar Nasional Indonesia Nomor 6989.57:2008. Pengujian kualitas air dilakukan oleh laboratorium yang terakreditasi. Metode perhitungan menggunakan rumus Langelier Saturation Index (LSI) A, B, C, D, dan rumus Saturation Index (SI) dari Standard Method APHA-AWWA-WEF. Hasil perhitungan LSI A, B, C, D, dan SI Standard Method APHA-AWWA-WEF menunjukkan bahwa tingkat korosivitas air di 9 waduk berpotensi menyebabkan korosi terhadap infrastruktur sumber daya air berbahan semen atau mortar dengan fc’ atau dengan nilai kuat tekan ≤ 30MPa. Kata kunci: infrastruktur sumber daya air, Langelier Saturation Index, Saturation Index, tingkat korosivitas air. Abstract. Water Corrosivity Level Againts the Water Resources Infrastructure Made of Cement or Mortar with fc' ≤ 30 MPa in 9 Reservoirs in Indonesia. Corrosion or damage that occurs in the infrastructure of water resources, especially those made of cement or mortar with fc' or with a compressive strength value of ≤ 30 MPa will be able to engender losses. Losses incurred, in the form of losses materially because of corrosion gnaw off all infrastructure assets and of course in losses terms of security, because it can threaten the safety of a human. Corrosion is a very important problem and will not be endless, as corrosion events occur continuously and sustainably. Corrosion events cannot occur by themselves, but because of certain factors that may cause corrosion. The purpose of this study is to determine the level of water corrosivity to the infrastructure of water resources made from cement or mortar with fc' or with a compressive strength value of ≤ 30 MPa in 9 reser","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"13 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122362356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pemanfaatan Asam Humat Dari Sampah Organik Sebagai Adsorben Pada Limbah Cair Sintesis Timbal (Pb)","authors":"Maimunawaro Maimunawaro, S. K. Rahman, Chairul Irawan","doi":"10.5614/JTKI.2020.19.1.5","DOIUrl":"https://doi.org/10.5614/JTKI.2020.19.1.5","url":null,"abstract":"Abstrak. Industri pelapisan logam disamping memiliki konstribusi bagi perekonomian Indonesia, namun dalam prosesnya menghasilkan limbah cair yang memberikan dampak negatif bagi lingkungan karena mengandung logam berat. Salah satu teknik pengolahan limbah cair yaitu adsorpsi menggunakan asam humat dari ekstraksi sampah organik yang dijadikan adsorben. Kelebihan proses adsorpsi ini ialah pengerjaannya mudah, biaya relatif murah, relatif aman dari kontaminasi zat-zat kimia, serta tidak memberikan polusi berarti bagi lingkungan. Ekstraksi asam humat dari sampah organik berlangsung secara bertahap menggunakan proses ekstraksi dengan 1 L NaOH dengan variasi pelarut 0,1 N dan 0,5 N. Karakterisasi sebelum dan sesudah ekstraksi menggunakan Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), dan Scanning Electron Microscope (SEM), masing-masing untuk mengetahui gugus fungsional, struktur kristal, serta struktur morfologi pada asam humat. Proses adsorpsi menggunakan asam humat sebagai adsorben dilakukan secara batch dengan massa adsorben 1 g/L, kecepatan pengadukan 150 rpm, temperatur ruang dan pH 6,7–7,0 selama 1 jam. Analisa setelah adsorpsi menggunakan metode Atomic Absorption Spectrofotometer (AAS) untuk uji kadar timbal (Pb (II)). Hasil adsorpsi timbal (Pb) pada kedua variasi pelarut adsorben dengan pH awal 6,7–7,0 memiliki keefektifan masing-masing mencapai hampir 98%. Kata kunci:adsorben, asam humat, ekstraksi, sampah organik. Abstract. Removal of Lead (II) of Synthetic Wastewater Using Humic Acid Extracted from Organic Waste As Adsorbent.Metal plating Industry mining productions contribute to the growth of the Indonesian economy, but during the processes usually create a negative environmental impact such as heavy metals. The adsorption method is one of various methods for wastewater treatment. The humic acid as adsorbent in the adsorption method had been extracted from organic waste. The advantages of this method are simple, cheap and secure from chemical contaminant. The extraction of humic acid from organic waste takes place gradually using 1 L NaOH with a variety of solvents of 0.1 N and 0.5 N.The humic acid before and after treatment was characterized using Fourier-transform infrared spectroscopy (FTIR) X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM).  The adsorption process was carried out in batch experiment with mass adsorbent of 1 g/L,  stirring speed of 150 rpm, room temperatur, pH around 6.7–7.0  for 1 hour. The result showed by Atomic Absorption Spectroscopy (AAS) analysis characterize that adsorption lead (II) in several adsorbent concentrations at pH 6.7–7.07 has effectiveness 98%. Keywords: adsorbents, extraction, humic acid, organic waste. ","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130336741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sabun Kalsium dari PFAD untuk Pakan Ruminansia: Kualitas PFAD Sebagai Sumber Asam Lemak Bebas","authors":"Lienda Handojo, Antonius Indarto, Dian Shofinita, Muhammad R. Saadi, Dea Yulistia, Fathinah I. Hasyyati","doi":"10.5614/JTKI.2020.19.1.2","DOIUrl":"https://doi.org/10.5614/JTKI.2020.19.1.2","url":null,"abstract":"Abstrak. Dalam rangka meningkatkan komoditas susu di Indonesia, pemerintah menargetkan sapi perah lokal harus mampu menyuplai 41% produksi susu dalam negeri pada 2022. Salah satu cara untuk menaikkan produksi susu sapi adalah memberikan suplemen pakan berupa sabun kalsium. Sabun kalsium telah banyak digunakan di luar negeri, namun tidak di Indonesia, untuk menaikkan produksi susu sekaligus fertilitas ruminansia. Sabun kalsium dapat dibuat melalui reaksi fusi termodifikasi antara Palm Fatty Acid Distillate (PFAD) sebagai sumber asam lemak bebas dengan sumber kalsium. Penelitian ini mengevaluasi pengaruh jenis PFAD terhadap kualitas produk sabun kalsium. PFAD yang digunakan berasal dari beberapa industri pengolahan kelapa sawit di Indonesia, yaitu Kabupaten Sidoarjo, Kabupaten Bekasi, Kota Bekasi, dan Kabupaten Pelalawan dengan rentang angka asam 195–221 mg KOH/g sampel. Produk sabun kalsium yang dihasilkan kemudian dianalisis nilai angka asam untuk menguantifikasi kualitasnya. Keempat produk sabun kalsium secara keseluruhan memiliki angka asam di bawah 1 mg KOH/g sampel. Rendahnya angka asam pada produk membuktikan bahwa keempat sumber PFAD dapat digunakan sebagai bahan baku pembuatan sabun kalsium dengan kualitas baik. Kata kunci:angka asam, kalsium oksida, PFAD, pakan ruminansia, sabun kalsium. Abstract. Calcium Soap from PFAD for Ruminant Feed: Quality of PFAD as a Source of Free Fatty Acids. In order to increase the milk commodity in Indonesia, the government targets local dairy cattle to be able to supply 41% of domestic milk production by 2022. One way to increase the production of cow's milk is to provide a dietary supplement in the form of calcium soap. Calcium soap has been widely used overseas, but not in Indonesia, to increase milk production as well as ruminant fertility. Calcium soaps can be made by modified fusion reactions between PFAD as a source of free fatty acids with a calcium source. This study evaluated the effect of PFAD type on the quality of calcium soap products. PFAD used were obtained from several palm oil processing industries in Indonesia, namely Sidoarjo regency, Bekasi regency, Bekasi city, and Pelalawan regency with the acid number 195–221 mg KOH/g sample. The resulting calcium soap product is then analyzed for the acid number to quantify its quality. The four calcium soap products had an acid number below 1 mg KOH / g sample. The low acid number in the product indicates that the four sources of PFAD can be used as raw material for producing calcium soap with good quality. Keywords: acid value, calcium oxide, calcium soap, PFAD, ruminant feed. ","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134319698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TOWARDS KINETIC REGIME OF REVERSE FLOW OPERATION","authors":"Y. Budhi","doi":"10.5614/jtki.2005.4.3.8","DOIUrl":"https://doi.org/10.5614/jtki.2005.4.3.8","url":null,"abstract":"An analysis of reverse flow operation and its experimental study for ammonia oxidation to produce either N2, N2O, and NO have been carried out. An experimental set-up of reverse flow reactor was constructed for a laboratory scale. The experiment under steady state operation was performed as a base case in order to judge the potential during the reverse flow operation. Aim was to investigate the behavior of reverse flow operation and to observe the reactor performance. Focus was on the comparison of the steady state and reverse flow operations. The experiments show that the behavior of reverse flow reactor is strongly influenced by the ratio of the switching time over the residence time. The ammonia conversion during the regular reverse flow operation shows lower values compared to the steady state operation which is even worse during asymmetric mode. The product distributions may change under flow reversal, depending on the operating conditions, regime of operation, and operation mode.Keywords : Reverse Flow Operation, Fixed Bed Reactor, Selectivity Manipulation, Steady State Operation, Ammonia OxidationAbstrak Sebuah analisis operasi aliran bolak-balik dan studi eksperimental oksidasi amoniak untuk menghasilkan baik N2., N2O, dan NO telah dilakukan. Sebuah perangkat eksperimen reaktor aliran bolak-balik dikonstruksi untuk skala laboratorium. Eksperimen dalam operasi keadaan tunak dilakukan sebagai kasus dasar untuk menilai potensi operasi aliran bolak-balik. Tujuan penelitian ini adalah untuk meneliti kelakuan operasi aliran bolak-balik dan untuk mengamati kinerja reaktor. Kajian ini dititikberatkan pada perbandingan operasi keadaan tunak dan operasi aliran bolak-balik. Hasil percobaan menunjukkan bahwa kelakuan reaktor aliran bolak-balik sangat dipengaruhi oleh nisbah waktu pembalikan arah aliran (switching time) terhadap waktu tinggal. Konversi amomiak dalam operasi aliran bolak-balik menunjukkan nilai yang lebih rendah dibandingkan dengan operasi keadaan tunak dan dalam mode asimetrik konversinya bahkan lebih rendah lagi. Distribusi produk dapat berubah dalam pembalikan aliran yang bergantung pada kondisi-kondisi operasi, daerah operasi, dan mode operasi.Kata Kunci : Operasi Aliran Bolak-balik, Reaktor Fixed Bed, Manipulasi Selektivitas, Operasi Tunak, Oksidasi Amoniak","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134190539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pemuatan listrik bipolar untuk partikel aerosol","authors":"Heru Setyawan","doi":"10.5614/jtki.2005.4.3.4","DOIUrl":"https://doi.org/10.5614/jtki.2005.4.3.4","url":null,"abstract":"Bipolar diffusion charging of aerosol particles has been studied theoretically using Fuchs theory. Experimental data measured by several researchers available in the published literature were used to verify the calculation results. The calculation results show that Fuchs theory has been successfully used to predict the experimental data of the charging probability of submicron aerosol particles. The combination probability of ion-particle increases with the increase of particle size, both for particle and ion with the same sign and those with the opposite sign. However the combination probability is larger if the charges of particle and ion are of the opposite sign. Generally, Fuchs theory is not too easy to deal with due to the ill-defined of all parameters used, namely ion mass and ion mobility. These cause many possibilities of parameter combination that can give a good agreement with experimental data. Thus, in order to interpret the experimental results properly, the two parameters should be measured simultaneously with aerosol measurements.Keywords: Aerosol, Bipolar Charging, Combination ProbabilityAbstrakPemuatan listrik difusi bipolar partikel aerosol telah dipelajari secara teoritis menggunakan teori Fuchs. Sebagai verifikasi digunakan data eksperimen beberapa peneliti yang tersedia dalam literatur yang telah dipublikasikan. Hasil perhitungan menunjukkan bahwa teori Fuchs berhasil memprediksi dengan baik data eksperimen probabilitas pemuatan listrik partikel aerosol dalam rentang ukuran partikel berukuran submikron. Probabilitas penggabungan ion-partikel semakin besar dengan semakin besarnya ukuran partikel, baik untuk partikel dan ion yang memiliki tanda yang berlawanan maupun yang memiliki tanda yang sama. Akan tetapi, probabilitas penggabungan untuk partikel dan ion yang memiliki tanda yang berlawanan memiliki nilai yang lebih besar. Pada umumnya teori Fuchs tidak terlalu mudah untuk digunakan yang disebabkan oleh tidak terdefinisikannya dengan baik semua parameter yang digunakan, yaitu  massa ion dan mobilitas ion. Hal ini mengakibatkan banyak kemungkinan kombinasi parameter yang bisa menghasilkan kesesuaian yang bagus dengan data hasil pengukuran. Jadi, agar dapat menginterpretasikan hasil pengukuran dengan tepat, kedua besaran tersebut harus diukur secara serempak denganpengukuran aerosol.Kata Kunci: Aerosol, Pemuatan Listrik Bipolar, Probabilitas Penggabungan","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123806499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dinamika tetes dalam kolom isian","authors":"D. Ariono, Dwiwahju Sasongko, Priyono Kusumo","doi":"10.5614/jtki.2008.7.1.1","DOIUrl":"https://doi.org/10.5614/jtki.2008.7.1.1","url":null,"abstract":"To date, evaluation of the performance of liquid-liquid extraction in packed columns has not been able to produce satisfactory results, because the correlations used in this evaluation are empirical in nature, with a very limited range of validity. One of the causes of this limitation is the use of the assumption that the dynamics of liquid dispersed in droplets is constant (in terms of shape, dimensions, and numbers), so that the mass transfer interfacial area and mass transfer coefficient in the column are assumed to be constant. In reality, dynamics of droplets in a column is not constant, due to the imbalance between droplet coalescence and disintegration. For a given droplet diameter, there is an increase in numbers of droplets due to coalescence of smaller droplets, and a  decrease in numbers of droplets due to disintegration into smaller droplets. These coalescence and disintegration phenomena may be caused by various factors, including the existence of packings which impede the flow of droplets. These phenomena impact the mass transfer rate from continuous to dispersed phase, and vice versa, due to a variation in the interfacial contact area and mass transfer coefficient. The observation of droplet dynamics from droplet formation until its motion through void spaces between packings is a critical factor in developing a model that can describe the performance of the packed column. The dynamics of droplets is influenced by various operational and physical variables.  A droplet dynamics experiment has been undertaken, aimed at obtaining the droplet size distribution at specific heights along the column. This distribution is to be used to develop mass transfer coefficient correlations in the continuous and dispersed phases.Keywords: droplet size distribution, packed column Abstrak Evaluasi unjuk kerja ekstraksi cair-cair dalam kolom isian (packed column) hingga saat ini belum dapat memberikan hasil yang memuaskan karena korelasi-korelasi yang  digunakan  masih  bersifat  empiris serta daerah keberlakuannya sangat terbatas. Salah satu penyebab keterbatasan berlakunya korelasi tersebut ialah penggunaan anggapan bahwa dinamika cairan yang terdispersi dalam bentuk tetesan bersifat konstan (bentuk, ukuran serta jumlahnya), sehingga harga luas perpindahan massa dan harga koefisien perpindahan massa dalam kolom dianggap tetap. Kenyataannya dinamika tetesan dalam kolom tidak konstan akibat adanya tetesan yang bergabung dan pecah dalam jumlah yang  tidak sama. Pada suatu harga diameter tetesan tertentu, ada penambahan jumlah tetesan akibat penggabungan tetesan­ tetesan yang ukurannya lebih kecil serta adanya pengurangan jumlah tetesan akibat pecahnya tetesan menjadi tetesan-tetesan yang lebih kecil. Peristiwa penggabungan dan pemecahan tetesan dapat disebabkan berbagai faktor temasuk adanya isian yang menghalangi gerakan tetesan. Kejadian tersebut akan mempengaruhi laju proses perpindahan massa dari fasa kontinyu ke fasa  terdispersi  atau sebaliknya,","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126933662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pencucian biodiesel dengan metode kontak gelembung","authors":"Yoel Pasae, J. Stephen","doi":"10.5614/jtki.2008.7.1.5","DOIUrl":"https://doi.org/10.5614/jtki.2008.7.1.5","url":null,"abstract":"Until today, the conversion of palm oil and recovery of glycerol as a byproduct have been extensively investigated. The purity level of product from the washing process in the biodiesel production technology heavily influences the quality of the biodiesel product. Therefore, this research is aimed at identifying the biodiesel washing process technology which is able to produce biodiesel according to standards for diesel engine application. The washing process employed in this research is the bubble method, which utilizes air bubbles injected from the bottom as a carrier form water molecules to the top layer of the contactor (the biodiesel phase) which contains glycerol, soap, and residual methanol. This bubble method enables the contact between water molecules and glycerol in the biodiesel phase, when the bubbles are swept to the fluid surface, without any external agitation. Experimental results indicate that with a three-stage washing process, the total glycerol content in the biodiesel can be reduced to approach the technical standards for combustion in diesel engines, or the Biodiesel Tentative Standards stipulated by the Indonesian Biodiesel Forum.Keywords: Bubble washing method, biodiesel AbstrakSampai dewasa ini proses konversi reaksi minyak kelapa sawit dan recovery gliserol sebagai hasil samping telah banyak diteliti. Tingkat kemurnian hasil dari tahapan proses pencucian dalam teknologi produksi biodiesel sangat menentukan kualitas biodiesel yang dihasilkan. Oleh karena itu penelitian ini bertujuan untuk mendapatkan teknologi proses pencucian biodiesel sehingga diperoleh biodiesel yang memenuhi standar untuk penggunaan pada mesin-mesin diesel. Proses pencucian yang dilakukan dalam penelitian ini yaitu metode gelembung, yang memanfaatkan gelembung udara yang dinjeksikan dari bagian bawah kolom (bottom) sebagai carrier (pembawa) molekul air ke bagian atas (fasa biodiesel) yang mengandung gliserol, sabun dan sisa metanol. Dengan metode gelembung ini, akan memungkinkan molekul air berkontakan dengan gliserol pada fasa biodiesel, saat terbawa ke permukaan fluida, tanpa dilakukan pengadukan eksternal. Dari hasil penelitian menunjukkan bahwa dengan sistim pencucian tiga tahap, kadar gliserol total dalam biodiesel dapat diturunkan hingga mendekati standar untuk pembakaran pada mesin diesel atau Standar Tentatif Biodiesel dari Forum Biodiesel Indonesia.Kata Kunci: Metode Pencucian Gelembung, Biodiesel.","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123663471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sistem penyimpanan energi panas kontak langsung menggunakan larutan Na2HPO4•12H2O","authors":"Panut Mulyono, I. M. Bendiyasa, Dita Budi Wibawa, Suryo Birowo","doi":"10.5614/jtki.2005.4.3.2","DOIUrl":"https://doi.org/10.5614/jtki.2005.4.3.2","url":null,"abstract":"The volumetric coefficient of heat transfer and the energy storage capacity in a direct contact thermal energy storage system using Na2HPO4.12H2O solution as thermal energy storage medium have been investigated. Hot kerosene was used as a heal transfer fluid. The experiments were carried out by bubbling hot kerosene from the bottom of a column containing Na2HPO4.12H2O solution. The column used in this experiment was made from glass of 3 mm in thickness with an inside diameter of 7 cm and a height of 100 cm. The effects of kerosene flow rate and kerosene bubble diameter on the volumetric coefficient of heat transfer and the storing rate of energy were studied. It was found that the volumetric coefficient of heat transfer was strongly affected by the flow rate of the kerosene and that the effect of the kerosene flow rate on the storing rate of energy was relative v high, while that of the effect of the bubble diameter was neglectable.Keywords: Direct Contact, Thermal Energy Storage System, Na2HPO4.12H2O Solution AbstrakPenelitian ini mempelajari sistem penyimpanan energi panas kontak langsung menggunakan larutan Na2HPO4.12H2O sebagai media penyimpan energi. Kerasin panas digunakan sebagai fluida alir sumber energi panas. Masalah yang dipelajari pada penelitian ini adalah nilai koefisien perpindahan panas volumetris dan kapasitas penyimpanan panasnya. Percobaan dilakukan dengan menggelembungkan kerasin panas dari dasar kolom yang berisi larutan Na2HPO4.12H2O. Kolom yang digunakan dibuat dari gelas dengan ketebalan 3 mm, mempunyai diameter dalam 7 cm, dan tinggi kolomnya adalah 100 cm. Parameter yang dipelajari dalam penelitian ini adalah pengaruh kecepatan volumetris kerosin dan pengaruh diameter gelembung kerosin terhadap nilai koefisien perpindahan panas volumetris  dan terhadap kecepatan penyimpanan panasnya. Hasil penelitian menunjukkan bahwa nilai koejisien perpindahan panas volumetris sangat dipengaruhi oleh kecepatan volumetris kerosin sehingga kecepatan penyimpanan panasnya juga sangat dipengaruhi oleh kecepatan volumetris kerosin. Pengaruh ukuran diameter gelembung terhadap nilai koefisien perpindahan panas volumetris dan terhadap kecepatan penyimpanan panasnya sangat kecil sehingga dapat diabaikan.Kata Kunci: Sistem Penyimpanan Energi Panas, Kontak Langsung, Larutan Na2HPO4.12H2O","PeriodicalId":138501,"journal":{"name":"Jurnal Teknik Kimia Indonesia","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128088880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}