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Investigasi Kapasitas Energi Termal pada Solar Water Heater Berbasis Kalor Laten dengan Variasi Debit Air Nadjib, Muhammad; Caroko, Novi; Thoharudin, Thoharudin; Darmawan, Hanifan
Semesta Teknika Vol 26, No 1 (2023): MEI
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v26i1.18196

Material penyimpan kalor pada solar water heater adalah air sebagai kalor sensibel. Kekurangan air adalah densitas energinya rendah. Material lain adalah dari golongan kalor laten (phase change material, PCM) yang memiliki densitas energi tinggi. Unjuk kerja termal SWH tipe aktif dengan tangki horizontal dan memakai PCM jenis paraffin wax terhadap perubahan debit aliran air belum pernah diungkap. Tujuan penelitian ini adalah untuk mendapatkan karakteristik pengaruh perubahan debit air terhadap kapasitas penyimpanan energi termal di tangki. Penelitian menggunakan SWH dengan tangki yang di dalamnya diletakkan kapsul silinder berisi paraffin wax RT55. Termokopel dipasang di sisi air dan PCM. Eksperimen dilakukan secara indoor memakai solar simulator. Debit aliran air yang digunakan adalah 1 lpm, 2 lpm dan 3 lpm. Penelitian ini mendapatkan hasil yaitu kapasitas energi termal untuk debit aliran tersebut masing-masing adalah 10,45 MJ, 10,59 MJ dan 10,71 MJ. Semakin besar debit air maka kapasitas penyimpanan energi termal semakin tinggi.

Performance of Motorcycle Fueled with Pertalite‒LDPE Pyrolytic Oil Blendings Thoharudin, Thoharudin; Santosa, Tito Hadji Agung; Sukmana, Rifky Adji
JMPM (Jurnal Material dan Proses Manufaktur) Vol 8, No 1 (2024): Juni
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/jmpm.v8i1.22274

Plastic use has expanded substantially, and its waste is primarily disposed of in landfills, which further harm ecosystems owing to inadequate waste management. Pyrolysis, which converts plastic waste into liquid fuel, is one of the potential chemical recycling alternatives for plastic. The purpose of this study is to determine the viability of using pyrolytic oil from an LDPE grocery bag as an alternative fuel for a four-stroke spark ignition motorcycle engine. The LDPE grocery bag was pyrolyzed at 500 oC at a heating rate of 3 oC/min, and the condensed pyrolytic vapor's characteristics were determined. Torque, power, and fuel consumption were investigated using a four-stroke spark ignition motorbike powered by pertalite‒LDPE pyrolytic oil blends. The results reveal that the properties of LDPE pyrolytic oil and pertalite were considerably different; hence, when the blending fuel was applied to the motorcycle, the engine torque and power decreased at low engine speed (2000‒3500 rpm), about equal at medium speed (3500‒5500 rpm), and increased at high engine speed (5500‒8500 rpm). Furthermore, the greater blending fuel greatly reduced fuel usage due to the high viscosity of the LDPE pyrolytic oil.

Effect of Temperature on Co-Pyrolysis of Palm Kernel Shell and Plastic Waste under Natural Catalysts Thoharudin, Thoharudin; Nadjib, Muhammad; Ayatullah, Maulana Wahyu
JMPM (Jurnal Material dan Proses Manufaktur) Vol. 8 No. 2 (2024): Desember
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/jmpm.v8i2.22053

Pyrolysis is a potential process for converting solid waste, such as biomass and plastic waste, into useful fuels and chemicals in liquid, solid, and gas forms. The pyrolysis temperature is a critical factor that influences the amount and quality of the product. Furthermore, the use of natural catalysts such as calcium oxide and natural zeolite affects the pyrolysis products. Thus, the purpose of this study is to evaluate the influence of temperature on the amount and quality of pyrolysis products, especially pyrolysis oil, using calcium oxide and natural zeolite catalysts. Pyrolysis was carried out in a stainless steel fixed-bed reactor. The temperature was kept at 400, 450, and 500 oC. The pyrolysis vapor was cooled with a water-jacket condenser, and the oil and wax were collected in an oil chamber. This study found that the pyrolysis temperatures had a substantial impact on the pyrolysis product yields by reducing the char product from 31.25% to 13.9% when the temperature rose in tandem with the fluctuations of other products (wax, liquid, and non-condensable gas). At 450 oC, the liquid product acquired its maximum density, viscosity, heating value, and acidity, which were 906.7 kg/m3, 2.2 cSt, 37.83 MJ/kg, and pH 6.2, respectively. Furthermore, increased temperature promoted the formation of aliphatic hydrocarbons..

Performance of Motorcycle Fueled with Pertalite‒LDPE Pyrolytic Oil Blendings Thoharudin, Thoharudin; Santosa, Tito Hadji Agung; Sukmana, Rifky Adji
JMPM (Jurnal Material dan Proses Manufaktur) Vol. 8 No. 1 (2024): Juni
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/jmpm.v8i1.22274

Plastic use has expanded substantially, and its waste is primarily disposed of in landfills, which further harm ecosystems owing to inadequate waste management. Pyrolysis, which converts plastic waste into liquid fuel, is one of the potential chemical recycling alternatives for plastic. The purpose of this study is to determine the viability of using pyrolytic oil from an LDPE grocery bag as an alternative fuel for a four-stroke spark ignition motorcycle engine. The LDPE grocery bag was pyrolyzed at 500 oC at a heating rate of 3 oC/min, and the condensed pyrolytic vapor's characteristics were determined. Torque, power, and fuel consumption were investigated using a four-stroke spark ignition motorbike powered by pertalite‒LDPE pyrolytic oil blends. The results reveal that the properties of LDPE pyrolytic oil and pertalite were considerably different; hence, when the blending fuel was applied to the motorcycle, the engine torque and power decreased at low engine speed (2000‒3500 rpm), about equal at medium speed (3500‒5500 rpm), and increased at high engine speed (5500‒8500 rpm). Furthermore, the greater blending fuel greatly reduced fuel usage due to the high viscosity of the LDPE pyrolytic oil.

Evaluation of Motorcycle Fueled with Blends of Gasoline and Pyrolytic Oil from Plastic‒Palm Kernel Shell Co-Pyrolysis Thoharudin, Thoharudin; Santosa, Tito Hadji Agung; Iswandi, Iswandi
ROTASI Vol 27, No 1 (2025): VOLUME 27, NOMOR 1, JANUARI 2025
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/rotasi.27.1.15-22

This study explores the co-pyrolysis of plastic grocery bags and palm kernel shells (PKS) as a sustainable solution for addressing plastic waste and producing renewable energy. A stainless-steel batch reactor operating at 500oC produced pyrolytic oil, char, and non-condensable gases, with a product yield of 48.3%, 26.7%, and 25.0%, respectively. Pyrolytic oil was characterized by higher viscosity, density, and oxygen content but a lower heating value compared to gasoline (pertalite). Various blends of pyrolytic oil (0–30%) with pertalite were tested in a 108 cc motorcycle engine. While pure pertalite offered better torque and power at low speeds, pertalite with 10% and 20% pyrolytic oil showed comparable engine performance at low to medium rotational speeds and better performance at high rotational speeds. In addition, blends with higher pyrolytic oil concentrations improved fuel efficiency, with the 30% blend achieving the best fuel economy at 33.3 km/L. The study concludes that pyrolytic oil can be a viable alternative fuel for motorcycles, particularly in carburetor systems, but requires further refinement to address particulate content and enhance compatibility with fuel injection systems.

Design and Analysis of Venturi Microbubble Generator Using Computational Fluid Dynamics Thoharudin, Thoharudin; Sunardi, Sunardi; Yudha, Fitroh Anugrah Kusuma; Nadjib, Muhammad; Nugroho, Arif Setyo
Eksergi Vol. 19 No. 2 (2023): MAY 2023
Publisher : Politeknik Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32497/eksergi.v19i2.4305

The necessity for dissolved oxygen in water is crucial for the survival and growth of aquatic organisms, particularly tilapia. Seventy-five percent of tilapia will die if there is insufficient dissolved oxygen in the water. This work seeks to develop a venturi bubble-generating technique to combat the scarcity of dissolved oxygen in the water. A floating pump with a capacity of 12 m3/hour was selected as the medium for distributing water and generating vacuum pressure to draw in air for mixing with the water flow in the venturi. Ansys Fluent was used to model piping and venturi systems. The piping system was modeled with a single-phase (water) flow at a steady state, whereas the flow in the venturi was modeled with a multiphase (air and water) flow under transient situations. The simulation findings revealed that the pressure drop at the 90-degree elbow was much greater (27.17 kPa) than that at the 45-degree elbow (16.53 kPa). A 1-inch input diameter venturi produced bubbles with an average diameter of 105 µm, whereas a ½ inch venturi bubble generator produced bubbles with an average diameter of 83 µm. Owing to the numerous advantages of adopting a six-outlet piping system with a ½ inch venturi, this design is recommended for floating pumps with a capacity of 12 m3/h.

CFD Simulation of Biomass Pyrolysis in a Fluidized Bed Reactor: Effect of Particle Shrinkage Model Thoharudin, Thoharudin
Formosa Journal of Science and Technology Vol. 3 No. 5 (2024): May 2024
Publisher : PT FORMOSA CENDEKIA GLOBAL

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55927/fjst.v3i5.9435

This study implemented the improved multistep comprehensive reaction for pyrolysis in a fluidized bed reactor. Particle shrinkage models were developed with variations of constant and nonconstant particle size with different char densities. Different biomass particle sizes were also investigated to observe their decomposition characteristic in a fluidized bed reactor. A multifluid model framework integrated with heterogeneous chemical reactions was developed to simulate fast biomass pyrolysis in a 2-D computational domain. The improved multistep comprehensive reaction exhibited good agreement with experimental pyrolysis product yields and their compositions. Shrinkage models with constant particle size promoted segregation and tended to generate coarse gradients between the dense zone and the freeboard. By contrast, the shrinkage models with nonconstant particle size favored more homogeneous biomass and char & metaplastic mass fractions in the reactor and reduced segregation. Models 4–6 exhibited positive representations of particle shrinkage with particle volume reductions of 54.4%, 54.3% and 50.7%, respectively

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