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"Pada sistem transmisi gas melalui pipa yang ditanam dalam tanah, seringkali pipa-pipa yang digunakan mengalami kebocoran ataupun kerusakan lainnya yang diakibatkan oleh korosi. Penyebab utama korosi yang menyerang pipa-pipa gas tersebut adalah lingkungan tempat pipa tersebut ditanam. Salah satu metode pencegahan yang dapat dilakukan pada pipa adalah dengan sistem proteksi halodik metode arus landing. Metode proteksi katedik arus landing ini diperlukan penelitian dan perancangan yang lebih mendalam terutama mengenai kondisi lingkungan tempat pipa gas tersebut ditanam."

"Corrosion is one of some necessary field that must be concorned by maritime and ship industries in Indonesia. The phenomenon of corrosion should be more attended, because it makes much money lost unpredictly. Corrosion couldn,t be avoid because the process happens natyrally but corrosion must be controlled to minimize the negative effects, specially in economics technics and safety fields. One of some popular methods to control the corrosion process in cathodic protection methods, with sacrificial anode. This research observed the effectivity of znanode (type S-3) that is used to protect a kind of material as cathode. The cathode material is A grade of mild steels, a material that is commonly used for many sea water constructions espicially for ship building materials. The observation was taken in fluid laboratory, marine engineering departement, the faculty of marine engineering & science, Hang Tuah University Surabaya. The weigh of sacrificial anode and the cathode is 1:4. They are connected and immersed in a model vessel with 35%o salinity sea water as corrosion media. This research presents that the average weight lost of the sacrificial anode is 1.637% and the average weigh lost of the cathode is 0.170% in 16 weeks observation. The calculation predicted that the sacrificial anode will be lost 5.5% of the weight in a year."

"Sistem proteksi katodik yang digunakan untuk melindungi jaringan pipa distribusi gas dari serangan korosi merupakan bagian yang penting dari sebuah instalasi pipa. Dalam pengukuran sistem proteksi katodik yang dilakukan, selalu ada nilai IR drop yang akan mengganggu keakuratan pengukuran. IR drop ini sangat dipengaruhi oleh karakteristik lingkungan tanah. Penelitian ini bertujuan untuk menganalisis pengaruh kondisi lingkungan dan resistivitas tanah terhadap nilai IR drop pada sistem proteksi katodik. Analisa dilakukan pada data-data hasil survey lokasi, hasil survey resistivitas tanah, hasil pengukuran ON- Instant OFF Potential; dan hasil pengujian sampel tanah pada nilai resistivitas tanah tertentu. Didapatkan lebih dari 47 lokasi mempunyai nilai IR drop lebih dari 100 mV. Nilai IR drop rata-rata untuk semua lingkungan sebesar 100 mV. Nilai IR drop rata-rata lingkungan pinggir laut sebesar 12 mV, tanah sawah sebesar 104 mV, pinggir sungai sebesar 83 mV, pinggir selokan sebesar 88 mV, taman/kebun sebesar 107 mV, dan pinggir jalan sebesar 104 mV. Berdasarkan data penelitian dapat disimpulkan bahwa kriteria minimal proteksi katodik -850 mV vs Cu/CuSO4 ON Potential tidak cukup untuk melindungi jaringan pipa dari serangan korosi, karena itulah kriteria tersebut harus diubah. Namun perubahan kriteria proteksi katodik tersebut selain karena mempertimbangkan adanya IR drop, harus mempertimbangkan pula faktor lain seperti historikal data dan pengamatan di lapangan.

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The cathodic protection system used to protect gas distribution pipelines from corrosion attacks is an important part of a pipeline installation. In the measurement of the cathodic protection system performed, there is always an IR drop value that will interfere with the measurement accuracy. IR drop is strongly influenced by soil environmental characteristics. This study aims to analyze the effect of environmental conditions and soil resistivity to the value of IR drop on cathodic protection system. The analysis was performed against the survey location data, the results of the soil resistivity survey, the ON Instant OFF Potential measurement result and the result of testing of soil samples at a certain soil resistivity value. There are more than 47 of locations that have IR drop values greater than 100 mV. The average drop IR value for all environments of 100 mV. The average IR drop value of the seafront is 12 mV, the wetland is 104 mV, riverbanks is 83 mV, the sewer edge is 88 mV, the park garden is 107 mV, and the roadside is 104 mV. Based on the research data, it can be concluded that the minimum criteria of cathodic protection 850 mV vs Cu CuSO4 ON Potential is not enough to protect the pipeline from corrosion attack, therefore the criteria must be changed. However, the minimum criterion of cathodic protection criterion in apart of considering the IR drop, should also consider other factors such as historical data and field observations."

"Dilakukan survey resistivitas tanah per 1 (satu) kilometer sepanjang pipeline dengan menggunakan metode four pin mengggunakan alat soil box untuk mendapatkan data perancangan proteksi katodik. Dari perhitungan dengan metode masa dan metode arus listrik yang dikeluarkan diperoleh jumlah anoda magnesium dengan spesifikasi berat 14,5 Kg, penampang melintang 0.015 m² dan panjang 0.55 m pada setiap satu kilometer pipa dengan spacing 0.914 m. Berdasarkan referensi data pipa, lingkungan, spesifikasi anoda korban, spesifikasi material urug dan resistivitas tanah, perancangan jumlah anoda korban yang dipasang pada pipa dihitung. Pengecekan perlindungan proteksi katodik dilakukan dengan pengetesan potensial polarisasi dan perhitungan hambatan total dilapangan sehingga arus korosi dan laju korosinya dapat diperkirakan. Perbandingan dilakukan dengan menguji laju korosi material API 5L Grade B di laboratorium dengan alat potensiostat yang menggunakan metode polarisasi sehingga kriteria perlindungan berdasarkan standard NACE RP 0169 dapat diklarifikasi. Penelitian juga dikembangkan dengan melihat perilaku korosi material pipa dengan pengujian struktur mikro, mekanik dan komposisi kimia pada pipa baru dan yang pipa telah terkorosi (akibat alat uji potensiostat). Juga sebagai pembanding, sampel pipa gagal akibat korosi turut diuji struktur mikro dan komposisi kimianya. Data dari pengujian ini akan memberikan gambaran mengenai disain umur pipa yang dirancang untuk kondisi dengan tekanan dan temperatur tertentu.

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A survey of soil resistivity per 1 (one) kilometer along the pipeline using the four pin method of a soil box tool to obtain cathodic protection design data. From the calculation with the mass method and the electric current method that was released, the number of magnesium anodes with a weight specification of 14.5 Kg, a cross section of 0.015 m2 and a length of 0.55 m in per one kilometer pipeline with spacing of 0.914 m. Based on pipe data references, environment, sacrificial anode specifications, load material specifications and soil resistivity, the design of quantity scarifical anodes installed on the pipe is calculated. Checking cathodic protection protection is done by testing the potential of polarization and calculating the total resistance in the field so that the corrosion current and the corrosion rate can be estimated. Comparison was carried out by testing the corrosion rate of API 5L Grade B material in the laboratory with a potentiostat device using the polarization method so that the protection criteria based on the NACE standard of Rp. 0169 could be verified. Research was also developed by looking at the corrosion behavior of pipe material by testing the microstructure, mechanics and chemical composition of the new pipe and the pipe has been corroded (due to the potentiostat test equipment). Also as a comparison, the defect pipe samples due to corrosion were tested for microstructure and chemical composition. Data from this test will provide an overview of the design life of pipes designed for conditions with certain pressure and temperature."

"Produksi hidrogen dengan elektrolisis plasma dapat memperbesar jumlah produk hidrogen yang dihasilkan. Sedangkan, energi yang dibutuhkan tidak terlalu besar dan ramah lingkungan. Tujuan dari penelitian ini adalah mempelajari pengaruh plasma katodik dan anodik, laju alir injeksi udara, dan konsentrasi awal elektrolit terhadap produksi hidrogen dan hidrogen peroksida serta produk samping yaitu amonia dan nitrat. Elektrolisis plasma menghasilkan radikal H• dan •OH yang merupakan bahan baku dari produksi hidrogen dan hidrogen. Penelitian ini menggunakan NaOH sebagai elektrolit, aditif metanol sebanyak 2%, dan stainless steel (SS-201) sebagai elektroda. Hasil produksi hidrogen diukur dengan Gas Chromatography, hidrogen peroksida diukur dengan titrasi permanganometri, dan amonia dan nitrat menggunakan metode spektroskopi UV-Vis. Produksi hidrogen paling banyak dihasilkan pada plasma anodik (720 V), laju alir udara 0,3 lpm, dan konsentrasi awal elektrolit 0,02 M. Pada kondisi tersebut, hidrogen yang diproduksi sebanyak 430,67 mmol dan hidrogen peroksida sebanyak 1,92 mmol, energi spesifik 3,01 kJ/mmol, dan erosi elektroda sebesar 0,04 gram.

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Hydrogen production by plasma electrolysis can increase the amount of hydrogen product produced. While the energy required is not too large and environmentally friendly. The purpose of this study was to learn the effect of cathodic and anodic plasma, injected air flow rate, and initial electrolyte concentration on the production of hydrogen and hydrogen peroxide and by-products, namely ammonia and nitrate. Plasma electrolysis produces H• and •OH radicals which are the raw materials of hydrogen and hydrogen production. This study used NaOH as an electrolyte, 2% methanol as an additive, and stainless steel (SS-201) as an electrode. Hydrogen production was measured by Gas Chromatography, hydrogen peroxide was measured by permanganometric titration, and ammonia and nitrate were measured by UV-Vis spectroscopy method. Most of the hydrogen production was produced in anodic plasma (720 V), air flow rate of 0.3 lpm, and initial electrolyte concentration of 0.02 M. Under these conditions, 430.67 mmol of hydrogen was produced and 1.92 mmol of hydrogen peroxide , specific energy of 3.01 kJ/mmol, and electrode erosion of 0.04 gram."

"ABSTRAKSintesis biodiesel dengan elektrolisis plasma sangatlah menjanjikan. Penelitian ini bertujuan mendapatkan efisiensi yang tinggi dalam sintesis biodiesel dari minyak kelapa sawit dengan metode elektrolisis plasma katodik. Bahan baku adalah minyak kelapa sawit, metanol, dan katalis KOH. Variasi percobaan meliputi kedalaman katoda, rasio molar minyak dengan metanol, tegangan operasi, dan penambahan gelembung udara. Yield tertinggi yang didapat adalah 98,76 pada kondisi kedalaman katoda 3 cm, rasio molar minyak-metanol 1:24, tegangan operasi 460 volt, dan tanpa gelembung udara. Efisiensi energi terbaik adalah 604 J/ml pada kondisi kedalaman katoda 3 cm, rasio molar minyak-metanol 1:24, tegangan operasi 300 volt, dan tanpa gelembung udara. Efisiensi proses yang tinggi terbukti mampu didapatkan dengan penggunaan plasma katodik. Hasil ini menunjukkan bahwa metode elektrolisis plasma katodik efektif digunakan dalam sintesis biodiesel.

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ABSTRACTSynthesis of biodiesel by using plasma electrolysis is very promising. This study aims to obtain high efficiency in the synthesis of biodiesel from palm oil by using cathodic plasma electrolysis method. The raw materials are palm oil, methanol, and KOH catalyst. Variations consist of cathode depth, oil methanol molar ratio, operating voltage, and the addition of air bubbles. The highest yield of 98.76 is obtained on the condition of cathode depth of 3 cm, oil methanol molar ratio of 1 24, operating voltage of 460 volts, and without air bubbles. The best energy efficiency of 604 J ml is obtained on the condition of cathode depth of 3 cm, oil methanol molar ratio of 1 24, operating voltage of 300 volts, and without air bubbles. High process efficiency is proved to be obtained by the use of cathodic plasma. These results indicate that cathodic plasma electrolysis method is effective to be used in the synthesis of biodiesel."