Material Energitika - Renewable Dan Non Renewable Energy [PDF]

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SUMBER ENERGI PERMASALAHAN 1. Pemakaian energi yg terus meningkat (kenaikan jumlah penduduk) 2. Cadangan energi fosil terbatas 3. Indnesia sdh menjadi net importer minyak bumi 4. DILEMA -> BBM MURAH , MAKA SUBSIDI NEGARA NAIK (NEGARA BANGKRUT) Energi Baru > Selin migas,. Ex : Baterai litium , magnesium Energi Terbaharukan > Surya, Angin, Hydro Energi baru Ternaharukan >Energi yg baru dan dpt diperbaharui ( Fuel Cell) NONRENEWABLE RESOURCES Sumber daya tak terbarukan adalah sumber daya alam yang tidak dapat dibuat ulang atau ditanam kembali pada skala yang sebanding dengan konsumsinya



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Nuclear energy is a nonrenewable resource because once the uranium is used, it is gone! Nuclear fission uses uranium to create energy. Coal, petroleum, and natural gas are considered nonrenewable because they can not be replenished in a short period of time. These are called fossil fuels.



Renewable resources adalah sumber daya alam yang bisa diisi ulang atau diperbaharu dan dibuat dalam waktu singkat.



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SOLAR, Energy from the sun. Geothermal, Energy from Earth’s heat WIND, BIOMASS, Energy from burning organic or living matter. WATER or HYDROELECTRIC, Energy from the flow of water.



KONVERSI ENERGI dan Efisiensi Super capasitor : dpt menyimpan energi tpi dlm waktu singka & kemudian diteruskan (kontinu) utk baterai komputer agar tdk lngsung mati. Ex : MnO2 Baterai : dpt menyimpan listrik dlm waktu lama dan dpt digunakan kembali (Batch) Silica (SiO2) Aerogel dan Xerogel Aplikasi Silica gel -> Baterai, Pelapis, Keras, berpori sehingga banyak udara di dalamnya Isolator - Digunakan sebagai bahan penjebak suhu Silica Aerogel  Lebih berpori sehingga lebih besar ukurannya dari xerogel dari massa yg sama Sebagai nanoteknologi glass foam yg berpori Aplikasi ; Absorbent(Porosity) Heat Insultion, Baterai (kerangkanya), Chemical Mechanical Planarization, Pembangkit Listrik Tenaga Panas Bumi(PLTB) dpt menghasilkan limbah padat (SiO2) 86.6% dll. Silica Xerogel  lebih rapat dan kuat, ukurannya lebih keci dri aerogel utk massa yg sama dan mudah dibuat Perpaduan Propertis Silika dan Carbon Silika (Kerangka) wafer -Luas permukaan besar -Pori tipe Open PORE (pori satu dgn yg lain tersambung) -stabil pd kondisi asam -Adsorbant inorganik polar. Ex H2O Carbon (Penempel) Topping -Luas permukaan besar -CLOSE PORE -Stabil pada kondisi asam dan basa -Adsorbent Non Polar Bereaksi secara ikatan fisikis, ikatan Gaya Vanderwalss dkk. KOMBINAS  Luas permukan semakin besar Perbandingan arus pada elektroda C = 3gram Kapasitas kecil C-SI = 3 gram Kapasitas Lebih besar, karena A>>



BATERAI Mengkonversi energi kimia yang tersimpan menjadi energi listrik Reaksi antara bahan kimia terjadi Terdiri dari sel elektrokimia Mengandung Elektroda Elektrolit Electrodes and Electrolytes Katoda Terminal positif Pengurangan kimia terjadi (mendapatkan elektron) Anoda Terminal negatif Oksidasi kimia terjadi (kehilangan elektron) Elektrolit memungkinkan: Pemisahan transportasi ion dan transportasi listrik Ion bergerak antara elektroda dan terminal Arus mengalir keluar dari baterai untuk melakukan pekerjaan Battery Overview Battery has metal or plastic case Inside case are cathode, anode, electrolytes Separator creates barrier between cathode and anode Current collector brass pin in middle of cell conducts electricity to outside circuit Primary Cell Salah satu penggunaan (non-rechargeable / disposable) Reaksi kimia yang digunakan, tidak bisa dibalik Digunakan pada saat penyimpanan yang lama dibutuhkan Tingkat pelepasan lebih rendah dari baterai sekunder Menggunakan: detektor asap, senter, remote kontrol Alkaline Battery • Alkaline batteries name came from the electrolyte in an alkane • Anode: zinc powder form • Cathode: manganese dioxide • Electrolyte: potassium hydroxide • The half-reactions are: Zn(s) + 2OH−(aq) → ZnO(s) + H2O(l) + 2e− [e° = -1.28 V] 2MnO2(s) + H2O(l) + 2e− → Mn2O3(s) + 2OH−(aq) [e° = 0.15 V] • Overall reaction: Zn(s) + 2MnO2(s) → ZnO(s) + Mn2O3(s) [e° = 1.43 V] • • • • • •



Zinc powered, basic electrolyte Higher energy density Functioning with a more stable chemistry Shelf-life: 8 years because of zinc powder Long lifetime both on the shelf and better performance Can power all devices high and low drains



• Use: Digital camera, game console, remotes



Zinc-Carbon Battery • Anode: zinc metal body (Zn) • Cathode: manganese dioxide (MnO2) • Electrolyte: paste of zinc chloride and ammonium chloride dissolved in water • The half-reactions are: Zn(s) → Zn2+(aq) + 2e- [e° = -0.763 V] 2NH4+(aq) + 2MnO2(s) + 2e- → Mn2O3(s) + H2O(l) + 2NH3(aq) + 2Cl- [e° = 0.50 V] • Overall reaction: Zn(s) + 2MnO2(s) + 2NH4Cl(aq) → Mn2O3(s) + Zn(NH3)2Cl2 (aq) + H2O(l) [e° = 1.3 V] • Zinc body, acidic electrolyte • Case is part of the anode • Zinc casing slowly eaten away by the acidic electrolyte • Cheaper then Alkaline • Shelf-life: 1-3 years because of metal body • Intended for low-drain devices • Use: Kid toys, radios, alarm clocks Secondary Cells Baterai isi ulang, Reaksi bisa segera dibalik Mirip dengan sel primer kecuali reaksi redoks dapat dibalik Pengisian ulang: Elektroda mengalami proses sebaliknya daripada pemakaian Katoda teroksidasi dan menghasilkan elektron Elektron diserap oleh anoda Nickel-Cadmium Battery • Anode: Cadmium hydroxide, Cd(OH)2 • Cathode: Nickel hydroxide, Ni(OH)2 • Electrolyte: Potassium hydroxide, KOH • The half-reactions are: Cd+2OH- → Cd(OH)2+2e2NiO(OH)+Cd+2e- →2Ni(OH)2+2OH• Overall reaction: 2NiO(OH) + Cd+2H2O→2Ni(OH)2+Cd(OH)2 • Maintain a steady voltage of 1.2v per cell until completely depleted • Have ability to deliver full power output until end of cycle • Have consistent powerful delivery throughout the entire application • Very low internal resistance • Lower voltage per cell



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Advantages: • This chemistry is reliable • Operate in a range of temperatures • Tolerates abuse well and performs well after long periods of storage • Disadvantages: • It is three to five times more expensive than lead-acid • Its materials are toxic and the recycling infrastructure for larger nickel-cadmium batteries is very limited



Lead-Acid Battery • Anode: Porous lead • Cathode: Lead-dioxide • Electrolyte: Sulfuric acid, 6 molar H2SO4 • Discharging (+) electrode: PbO2(s) + 4H+(aq) + SO42-(aq) + 2e- → PbSO4(s) + 2H2O(l) (-) electrode: Pb(s) + SO42-(aq) → PbSO4(s) + 2e• During charging (+) electrode: PbSO4(s) + 2H2O(l) → PbO2(s) + 4H+(aq) + SO42-(aq) + 2e(-) electrode: PbSO4(s) + 2e- → Pb(s) + SO42-(aq) • • • • •



The lead-acid cells in automobile batteries are wet cells Deliver short burst of high power, to start the engine Battery supplies power to the starter and ignition system to start the engine Battery acts as a voltage stabilizer in the electrical system Supplies the extra power necessary when the vehicle's electrical load exceeds the supply from the charging system



Lithium-Ion Battery • Anode: Graphite • Cathode: Lithium manganese dioxide • Electrolyte: mixture of lithium salts • Lithium ion battery half cell reactions CoO2 + Li+ + e- ↔ LiCoO2 Eº = 1V Li+ + C6+ e- ↔ LiC6 Eº ~ -3V • Overall reaction during discharge CoO2 + LiC6 ↔ LiCoO2 + C6 Eoc = E+ - E- = 1 - (-3.01) = 4V •



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Ideal material • Low density, lithium is light • High reduction potential • Largest energy density for weight Li-based cells are most compact ways of storing electrical energy Lower in energy density than lithium metal, lithium-ion is safe



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Energy density is twice of the standard nickel-cadmium No memory and no scheduled cycling is required to prolong battery life Advantages: • It has a high specific energy (number of hours of operation for a given weight) • Huge success for mobile applications such as phones and notebook computers • Disadvantages: • Cost differential • Not as apparent with small batteries (phones and computers) • Automotive batteries are larger, cost becomes more significant • Cell temperature is monitored to prevent temperature extremes • No established system for recycling large lithium-ion batteries



SOLID ELEKTROLIT Electrolyte - A substance that conducts electricity through the movement of ions. Most electrolytes are solutions or molten salts, but some electrolytes are solids and some of those are crystalline solids. Different names are given to such materials: – Solid Electrolyte – Fast Ion Conductor – Superionic Conductor Over the next two lectures we will be looking at materials which behave as solid electrolytes, their properties and applications. Ionic vs. Electronic Conductivity comparing the properties of ionic conductors with the conventional electronic conductivity of metals. logam Range Konduktivitas = 10 S / cm