Hasil Pencarian  ::  Simpan CSV :: Kembali

"ABSTRAKDi Indonesia, permasalahan sampah menjadi perbincangan dari hulu ke hilir yang terus dicari pemecahannya. Sampah kota di Indonesia memiliki potensi sebagai sumber energi terbarukan yang cukup besar. Namun, belum ada pemanfaatan secara maksimal karena terkendala aspek teknologi dan ekonomi. Teknologi pengolahan sampah menjadi listrik dengan metode landfill gas to power membutuhkan lahan yang besar untuk bisa menampung sisa tumpukan sampah. Dengan latar belakang dan potensi tersebut, pengujian ini bertujuan untuk membandingkan kestabilan tegangan dan frekuensi serita kinerja mesin dari generator set mesin diesel berbahan bakar solar yang dicampur syngas hasil gasifikasi sampah dan dibandingkan dengan solar murni pada skenario pembebanan 6,66%, 13,33%, dan 20%. Pengujian bahan bakar solar dengan campuran syngas mampu mempertahankan kinerja mesin diesel dengan kestabilan tegangan di antara +0,7%-+4,6% dari nilai nominal, kestabilan frekuensi di antara -1,26%-+1,34% dari nilai rata-rata, konsumsi bahan bakar 15,7 m3 syngas setara dengan 1 liter solar, tingkat kebisingan pada jarak 1 meter sebesar 76,28 dB-81,96 dB, dan suhu gas buang di antara 100,42-21,80 derajat celcius.

---

ABSTRACT

In Indonesia, the problem of waste becomes a conversation from upstream to downstream that the solution is continuously sought. Municipal Solid Waste (MSW) in Indonesia has the potential as a source of renewable energy that is quite large. However, there has not been a maximum utilization due to technological and economic aspects. The technology of processing waste into electricity using the landfill gas to power method requires a large amount of land to be able to accommodate the remaining piles of garbage. As that background and potential, this analysis aims to compare the stability of the voltage and frequency as well as the performance of the engine from diesel engine generator sets which the diesel fuel mixed with syngas from waste gasification results and compared to pure diesel in the loading scenario of 6.66%, 13.33%, and 20%. Testing diesel fuel with syngas mixture is able to maintain the performance of diesel engines with voltage stability between +0.7%-+4,6% of the nominal value, frequency stability between-1.26%+1.34% of the average value, fuel consumption of 15.4 m3 syngas is equivalent to 1 liter of diesel, the noise level at 1 meter is 76.28 dB 81.96 dB, and the temperature of the exhaust gas is between 100.42 121.80 celcius degree."

"Minyak kelapa sawit (CPO) merupakan salah satu jenis bahan dasar untuk pembuatan bahan bakar biodiesel. Di dalam pengolahan CPO menjadi minyak biodiesel terbukti membutuhkan tambahan biaya yang cukup besar sehingga terlihat tidak ekonomis. Penggunaan CPO sebagai bahan bakar minyak mesin diesel genset secara Iangsung maupun pencampuran dengan bahan bakar solar dimungkinkan mengingat komposisi utama dari minyak CPO adalah hidrokarbon. Penggunaan CPO sebagai bahan bakar membutuhkan peralatan pemanas bahan bakar, dimana sumber panasnya dapat diambil dari gas buang yang bertemperatur cukup tinggi atau dengan menggunakan pemanas listrik.

Pada penelitian ini dilakukan pengujian dan analisa pengaruh penggunaan CPO sebagai bahan bakar mesin diesel genset pada variasi campuran bahan bakar dan variasi temperatur bahan terhadap parameter-parameter unjuk kerja mesin diesel genset yang meliputi konsumsi bahan bakar spesifik, temperatur gas buang, opasitas gas buang, efisiensi thermal serta dampak kerusakanikeausan yang terjadi setelah mesin diesel genset menggunakan bahan bakar CPO atau campurannya. Sebagai pembanding dilakukan pengujian mesin diesel genset yang sejenis dengan menggunakan bahan bakar solar murni.

Hasil penelitian menunjukkan pemanfaatan campuran CPO sampai dengan konsentrasi 50% dapat digunakan secara Iangsung sebagai bahan bakar tanpa memerlukan pemanasan dengan unjuk kerja maksimal pads campuran CPO 30%. Pemanasan campuran CPO menurunkan densitas dan viskositas bahan bakar serta memperpendek ignition delay sehingga pembakaran yang terjadi lebih baik dan deposit pada ruang bakar lebih sedikit serta tidak menimbulkan keausan abnormal pads komponen mesin. Pemilihan temperatur pemanasan yang sesuai dengan konsentrasi campuran CPO akan menghasilkan unjuk kerja maksimal pada mesin diesel genset yang menggunakan standard penyetelan injection timing bahan bakar solar. Pemanfaatan campuran CPO 75% pada temperatur bahan bakar 80 °C dan CPO 100% pada temperatur 60 °C menghasilkan unjuk kerja maksimal dibandingkan pengoperasian pada temperatur lainnya.

---

Palm oil (CPO) is one of base material to produce biodiesel oil. In processing of CPO becomes biodiesel oil requires additional cost so that seen not economic. Usage of pure CPO as a fuel for diesel engine directly and also blending with diesel oil is enabled because of chemical composition of CPO is hydrocarbon. Usage of pure CPO as a fuel for diesel engine requires of fuel heater equipments, where source of heat can be taken away from high temperature of exhaust gas or by using electrical heater.

At this research, the study of using palm oil (CPO) as a fuel for diesel engine done by performance test and damage analysis of influence of usage CPO at various fuel mixture and various inlet fuel temperature. The performance parameters consist of fuel oil consumption, thermal efficiency, exhaust gas temperature, exhaust gas opacity and damage analysis of wear of piston, piston rings and cylinder liner including deposit at cylinder head and piston surface. Comparative testing against diesel oil which to be used at the other identical diesel engine specification.

Result of research shows that usage of CPO mixture up to concentration of 50% can be applied directly as a fuel for diesel engine without heating with maximum performance at concentration of CPO 30%. Heating of CPO mixture reduces density and fuel viscosity and cuts short ignition delay so that better combustion efficiency and slimmer deposit at combustion chamber and doesn't generate abnormal wear at machine component. Election of heating temperature which matching with concentration of CPO mixture will yield maximum performance of diesel engine using adjustment standard of diesel fuel injection timing. Usage of CPO 75% at fuel temperature 80°C and CPO 100% at temperature 60°C yields maximum thermal efficiency compared to operation at other temperature."

"Syngas yang dihasilkan bahan bakar batu bara melalui gasifikasi unit dimanfaatkan sebagai alternatif bahan bakar pada mesin generator set diesel, namun masih memanfaatkan sejumlah bahan bakar diesel sebagai igniter kompresinya. Dalam pemanfaatan syngas tersebut diperlukan suatu modifikasi terhadap saluran masuk syngas. Saluran masuk syngas diaplikasikan melalui saluran masuk udara yang sekaligus menjadi tempat pencampuran antara syngas dan udara tersebut (mixture valve) sebelum masuk ke dalam mesin. Mesin dengan dua bahan bakar yang berbeda tersebut disebut juga Dual - Fuel Engine. Karakteristik mesin dual fuel ini bergantung pada komposisi yang juga merupakan kualitas bahan bakar yang masuk. Dalam pencampuran kedua bahan bakar tersebut, perbandingan Hydrogen (H2) dan Carbon Monoxide (CO) pada control volume tertentu bervariasi terhadap nilai kalornya sehingga dalam perancangannya memerlukan perhitungan alternatif laju aliran bahan bakar syngas menurut nilai kalornya dengan efisiensi thermal yang dimiliki mesin.

---

Syngas that is produced by coal fuel through gasification unit used as a substitution fuel in a diesel engine generator set, but it still takes smaller amount of diesel fuel as the Compression Igniter. In using of two kind of those fuels, modification is needed at the intake of the engine. By applying the syngas inlet to the intake as well as a place of mixture happened between the air and the syngas (mixture valve) before get into the engine. The engine with those two different fuels is called Dual - Fuel Engine. Characteristics of dual fuel engines depend on composition or quality of the syngas. Syngas composition ratio between Hydrogen (H2) and Carbon Monoxide (CO) at certain volume control have many varies so it requires an alternative calculation of the syngas flow rate according to the heating value of the syngas with thermal efficiency of the engine which also influential factors."

"Peningkatan konsumsi listrik di Indonesia sejak tahun 2010 hingga 2030 mendorong perhatian terhadap pengembangan teknologi konversi termokimia, khususnya gasifikasi, untuk memenuhi kebutuhan energi. Gasifikasi adalah proses utama yang mengubah berbagai bahan baku padat, baik bahan baku fosil maupun sumber energi terbarukan, menjadi gas sintesis (syngas) yang kemudian dimanfaatkan lebih lanjut untuk memproduksi listrik melalui skema IGCC (Integrated Gasification Combined Cycle). Penelitian ini berfokus pada dampak dari variasi penggunaan bahan baku seperti batu bara kualitas rendah yang mewakilkan sumber energi fosil dan beberapa jenis biomassa yang mewakilkan sumber energi terbarukan, meliputi tandan kosong kelapa sawit, sekam padi dan kayu karet yang dipilih karena memiliki potensi tertinggi di Indonesia. Serta penggunaan variasi agen gasifikasi pada proses gasifikasi yaitu oksigen, udara, dan campuran udara dan uap air sehingga menghasilkan syngas. Metode simulasi dengan perangkat lunak Aspen Plus V.12 digunakan untuk mensimulasikan skema IGCC yang terdiri dari beberapa tahap proses, yaitu proses gasifikasi, pembersihan syngas, dan pembangkitan listrik. Masing-masing bahan baku dan agen gasifikasi disimulasikan sehingga didapatkan nilai kalor syngas serta daya listrik keluaran dan daya listrik yang dibutuhkan pada keseluruhan sistem IGCC. Nilai tersebut dievaluasi melalui perhitungan efisiensi cold gas yang meninjau seberapa efisien proses gasifikasi dalam mengubah bahan baku menjadi syngas serta perhitungan efisiensi termal dalam mengevaluasi seberapa efisien bahan baku terkonversi menjadi energi listrik dari keseluruhan proses pembangkit listrik. Data tersebut diolah untuk melihat korelasi karakteristik masing-masing syngas yang dihasilkan terhadap energi listrik yang dihasilkan.

---

The increase in electricity consumption in Indonesia from 2010 to 2030 has led to a focus on the development of thermochemical conversion technologies, particularly gasification, to meet energy needs. Gasification is the primary process that converts various solid feedstocks, whether fossil or renewable, into synthesis gas (syngas), which is further utilized to produce electricity through the Integrated Gasification Combined Cycle (IGCC) scheme. This study concentrates on the impact of using various feedstock such as low rank coal, representing fossil feedstocks, and several types of biomass including oil palm empty fruit bunches, rice husks, and rubberwood chosen for their high potential in Indonesia. Additionally, it explores the use of various gasification agents—oxygen, air, and air-steam—to produce syngas. Simulation methods utilizing Aspen Plus V.12 software are employed to simulate the IGCC scheme encompassing several process stages: gasification, syngas clean-up, and power generation. Each feedstock and gasification agent are respectively simulated to obtain syngas calorific values, electrical power output, and power required for the entire IGCC system. These values are evaluated through cold gas efficiency calculations, assessing the gasification process efficiency in converting feedstock into syngas, and thermal efficiency calculations to evaluate how efficiently feedstock is converted into electric energy in the overall power generation process. The data is processed to understand the correlation between the characteristics of the resulting syngas and the electric energy produced."

"Bioethanol is a renewable and oxygenated bio-based resource with the potential to reduce particulate emissions in direct fuel injection diesel engines. This study aims to further diminish the outflow of a Diesel Fuel Engine motor fueled by diesel-bioethanol by identifying the most suitable blend by applying various blends of diesel-bioethanol, namely E10, E20, E50, and E80 blends. The Diesel engine had been tested using solely diesel fuel and then with bioethanol blends for comparison purposes. The results show that bioethanol fuel can provide a lower torque for the Diesel engine, but a similar engine performance occurs in terms of Horse Power. However, the presence of bioethanol inside the blended fuels increases the emissions of Unburned Hydrocarbon, (HC), CO, CO2, and NOx compared to engines that use only Pure Diesel. E10 has been found as the most ideal blend from all the fuels tested. Further research is required to distinguish the E80 fuel blend, as it is unable to be tested on a 6-cylinder engine, since the standard running Diesel engine suitable for the E80 blend fuel is a single cylinder."

"Penelitian ini dilakukan dengan proses deposisi dan evaporasi bahan bakar diesel yang dilakukan secara berulang pada sebuah pelat panas. Pelat dipanaskan dengan variasi temperatur di dalam ruang tertutup sehingga kondisinya mendekati kondisi riil pada engine. Pengujian ini menggunakan hot room temperature test rig. Dari pengujian ini, pengaruh temperatur terhadap pertumbuhan dan karakteristik deposit dapat diamati. Penelitian ini lebih mengarah ke jumlah deposit. Jumlah deposit yang berbeda di setiap temperatur dapat menunjukkan temperatur yang optimal untuk mengendalikan pertumbuhan deposit.

---

Repetitive process of diesel fuel deposition and evaporation on hot plate are done in this study. The plate was heated at various temperature in closed systems for approaching the real engine condition. This process was done in hot room temperature test rig. Effect of temperature to deposits growth and characteristic could be observed through this repetitive process. Then, the aim of this study is more likely to total deposits. Total deposits structure at every temperature could show the optimum temperature to control the deposits growth."

"Penelitian analisis tekno-ekonomi Crude Palm Oil (CPO) bertujuan untuk mengetahui karakteristik viskositas dan densitas CPO sebagai bahan bakar mesin diesel serta dampak penggunaan CPO terhadap karakteristik mesin seperti performance, karakteristik parameter pembakaran, keandalan dan emisi gas buang yang dihasilkan.Penelitian dilakukan dengan metode pengujian operasi (running test) menggunakan 100% CPO selama 375 jam 58 menit pada mesin diesel Type MAK 8M453B dengan 8 cylinder inline dan daya mampu gross 1,200 KW. Suhu pemanasan CPO pada Flow Control Module selama pengujian dijaga pada rentang 77 ⁰C s.d 83 ⁰C untuk mendapatkan rentang viskositas kinematik CPO di inlet mesin  sebesar 11 cSt s.d. 13 cSt. Selama running test, dilakukan uji performance, uji karakteristik pembakaran (engine analyzer), uji emisi gas buang dan pengambilan sampel CPO. Sementara sebelum dan sesudah running test dilakukan uji sampel CPO serta minyak pelumas. Uji Scanning Electron Microscope (SEM) juga dilakukan untuk mengetahui komposisi logam pada deposit.Hasil penelitian menunjukkan bahwa viskositas kinematik dan densitas CPO cenderung menurun ketika suhu dinaikkan dengan kurva berbentuk parabolic polinomial untuk viskositas kinematik dan cenderung linier untuk densitas. Specific Fuel Consumption (SFC) pada beban maksimum 1.200 kW gross sebesar 0,298 liter/kWh. Persamaan polinomial SFC terhadap beban adalah y = 10^-07x² - 0,0003x + 0,4496. Kadar emisi gas buang NO_x sebesar 2.075,4 mg/Nm³ s.d. 2797,7 mg/Nm³, melebihi batasan standar baku mutu lingkungan (maksimum 1.400 mg/Nm³). Terbentuk deposit keras berupa lelehan di permukaan cylinder head, piston dan valve serta nozzle dengan kandungan komposisi logam Calcium (Ca) yang bersifat keras dan sulit dibersihkan. Akumulasi deposit menyebabkan tergoresnya dinding permukaan liner.Pengoperasian menggunakan bahan bakar CPO menurunkan tekanan pembakaran sebesar 14 % pada beban maksimum dibandingkan beroperasi menggunakan biodiesel/B20; menurunkan Indicated Horse Power (IHP) mesin rata-rata sebesar 7,44 %; memperpendek interval pemeliharaan periodik yang berdampak pada peningkatan signifikan pada kebutuhan biaya fix dan variable O&M dan penurunan capacity factor mesin. Kualitas minyak pelumas mengalami degradasi dengan indikasi kenaikan viskositas minyak pelumas dan terdapat kenaikan kontaminan logam silica (Si) dan besi (Fe).Berdasarkan hasil perhitungan pada analisis keekonomian, harga keekonomian CPO tahun 2018 sebesar Rp.7.238,11/liter, lebih rendah Rp. 1.142,73/liter terhadap harga indeks pasar rata-rata pada tahun 2018. Sementara pada tahun 2019, harga keekonomian bahan bakar CPO sebesar Rp. 6.515,25/liter, lebih rendah Rp. 1.002,54/liter terhadap harga indeks pasar rata-rata CPO pada tahun 2019 dan lebih rendah Rp. 1.857,42/liter terhadap harga suplier CPO di ULPLTD-MG Bontang.

---

The techno-economic analysis of Crude Palm Oil (CPO) aims to determine the viscosity and density characteristics of CPO as diesel engine fuel and the impact of CPO use on engine characteristics such as performance, characteristics of combustion parameters, reliability and exhaust emissions produced.

The research method was carried out by running test using 100% CPO for 375 hours 58 minutes on a diesel engine MAK Type 8M453B with 8 inline cylinders and a gross capable power of 1,200 kW. CPO heating temperature in the Flow Control Module during testing is maintained in the range of 77 ⁰C to 83 ⁰C to get the kinematic viscosity range of CPO at the engine inlet of 11 cSt to 13 cSt. During the running test, a performance test, a combustion characteristics test (engine analyzer test), a flue gas emission test and CPO sampling was conducted. While before and after running test CPO and lubricant oil samples were tested. The Scanning Electron Microscope (SEM) test was also carried out to determine the metal composition of the deposit.

The results showed that kinematic viscosity and CPO density tended to decrease when the temperature was raised with a polynomial shaped parabolic curve for kinematic viscosity and tended to be linear for density. Specific Fuel Consumption (SFC) at a maximum load of 1,200 kW gross is 0,298 liters/ kWh. The SFC polynomial equation for load is y = 10^-07x² - 0,0003x + 0,4496. NOx exhaust gas emission levels of 2,075.4 mg/Nm³ s.d. 2,797.7 mg/Nm³, exceeding the limits for environmental quality standards (maximum 1,400 mg/Nm³). A hard deposit formed in the form of a melt on the surface of the cylinder head, piston and valve as well as a nozzle with a metal composition of Calcium (Ca) which is hard and difficult to clean. Accumulated deposits cause scratching of the liner surface.

Operations using CPO fuel reduce combustion pressure by 14% at maximum load compared to operating using biodiesel/ B20; reduce machine Indicated Horse Power (IHP) by an average of 7.44%; shortening periodic maintenance intervals which results in a significant increase for fix and variable O&M costs and a decrease in engine capacity factor. The quality of the lubricating oil is degraded with an indication of an increase in the viscosity of the lubricating oil and an increase in metal (Si) and iron (Fe) contaminants.

Based on economic analysis, the economic price of CPO in 2018 is Rp.7,238.11 /liters, lower Rp. 1,142.73 /liters against the average market index price in 2018. While in 2019, the economic price of CPO fuel is Rp. 6,515.25 / liters, lower Rp. 1,002.54 / liters against the CPO average market index price in 2019 and lower Rp. 1,857.42 / liters of CPO supplier prices in ULPLTD-MG Bontang."

"Beberapa polutan udara yang mencemari lingkungan antara lain seperti nitrogen oksida (NOx), sulfur dioksida (SO2), dan karbon monoksida (CO). Teknologi kontaktor membran merupakan teknologi alternatif dalam menyisihkan gas NOx, SO2, dan CO karena keunggulannya berupa luas area spesifik yang tinggi. Penelitian ini akan mempelajari proses penyisihan gas buang mesin diesel berupa NOx, SO2, dan CO menggunakan pelarut H2O2 dan NaOH pada modul membran serat berongga berbahan polisulfon. Gas buang mesin diesel akan dialirkan pada bagian tube membran, sedangkan pelarut H2O2 dan NaOH berada di bagian shell dan bersifat statis. Variabel bebas yang diuji pada penelitian ini adalah laju alir gas umpan dan konsentrasi pelarut H2O2. Berdasarkan hasil uji, efisiensi penyisihan gas NOx, SO2, dan CO tertinggi pada laju alir gas 100 mL/menit dan konsentrasi H2O2 0,5 M berturut-turut, yaitu sebesar 99,56%, 99,79%, dan 99,28%, fluks perpindahan massa NOx, SO2, dan CO tertinggi pada laju alir gas 200 mL/menit menit dan konsentrasi H2O2 0,5 M berturut-turut, yaitu sebesar 1,13 x 10-6 mmol/cm2.s, 9,42 x 10-7 mmol/cm2.s, dan 8,93 x 10-7 mmol/cm2.s serta NOx, SO2, dan CO loading tertinggi pada laju alir gas 200 mL/menit menit dan konsentrasi H2O2 0,05 M berturut-turut, yaitu sebesar 1,72 x 10-4 mmol NOx/mmol H2O2.s, 1,3 x 10-4 mmol SO2/mmol H2O2.s, dan 1,2 x 10-4 mmol CO/mmol H2O2.s.

---

Some air pollutants that affect the environment include nitrogen oxides (NOx), sulfur dioxide (SO2), and carbon monoxide (CO). Membrane contactor technology is an alternative technology in NOx, SO2, and CO gases because of its advantages, such as high specific area. This study investigates removing exhaust gases from diesel engines in the form of NOx, SO2, and CO using H2O2 and NaOH solvents on hollow fiber membrane modules made of polysulfone. The exhaust gas of the diesel engine will be in the membrane part of the tube, while the solvent H2O2 and NaOH are in the shell and are static. The independent variables tested in this study were the gas feed flow rate and the concentration of H2O2. Test results, the highest absorption efficiency of NOx, SO2, and CO gas was at a gas flow rate of 100 mL/min and H2O2 0.5 M, respectively, which are 99.56%, 99.79%, and 99.28%, the highest mass transfer flux of NOx, SO2, and CO at a gas flow rate of 100 mL/min and H2O2 0.5 M, respectively, namely 1.13 x 10-6 mmol/cm2.s, 9.42 x 10-7 mmol/cm2.s, and 8.93 x 10-7 mmol/cm2.s, and also highest NOx, SO2, and CO loading at a gas flow rate of 100 mL/min and H2O2 0.05 M, respectively, namely 1.72 x 10-4 mmol NOx/mmol H2O2.s, 1.3 x 10-4 mmol SO2/mmol H2O2.s, and 1.2 x 10-4 mmol CO/mmol H2O2.s."

"The use of water-in-diesel (W/D) emulsion fuel has the potential to promote better performance with lower emissions in existing diesel engines. The present study aims to analyzes the influence of operating parameters on the overall engine performance and emission characteristics using W/D emulsion fuel and to obtain the optimum level for favorable performance and emission levels. The engine operating parameters were optimized using a Taguchi–grey relation based multi-response optimization tool. Two controlling parameters, namely compression ratio (CR) and percentage of W/D, were considered as input process parameters. An L16 orthogonal array was used to collect the output responses (performance and emissions) under varying engine load conditions. The signal-to-noise (S/N) ratio and grey relational analysis were used to analyze the performance and emission parameters. From the results obtained, it is noted that both controlling parameters have a significant effect on the performance and emission levels. The optimum level of performance and emission levels are obtained at a CR of 18 and water concentration of 10%. Moreover, under these optimum conditions, i.e. at 10% of water concentration, the fuel properties are at par with the standard diesel fuel properties requirement."