(Kertas ini mengandungi 10 soalan dalam 8 halaman yang dicetak) (This question paper consists of 10 questions on 8 printed pages)

Transcription

1 UNIVERSITI MALAYA UNIVERSITY OF MALAYA PEPERIKSAAN IJAZAH SARJANA MUDA SAINS EXAMINATION FOR THE DEGREE OF BACHELOR OF SCIENCE SESI AKADEMIK 2015/2016 : SEMESTER II ACADEMIC SESSION 2015/2016 : SEMESTER II SCES3140 : KIMIA INDUSTRI II INDUSTRIAL CHEMISTRY II Jun 2016 June 2016 Masa: 2 jam Time: 2 hours ARAHAN KEPADA CALON: INSTRUCTIONS TO CANDIDATES: Kertas ini mengandungi seksyen A dan B This paper has section A and B Jawap semua soalan. Please answer all questions. (Kertas ini mengandungi 10 soalan dalam 8 halaman yang dicetak) (This question paper consists of 10 questions on 8 printed pages)

2 Jawab semua soalan Answer all questions BAHAGIAN A (50 MARKAH) SECTION A (50 MARKS) 1. Permintaan biofuel meningkat di seluruh dunia disebabkan ia merupakan tenaga hijau yang boleh diperbaharui dan sumber yang banyak dijumpai: The demand of biofuel is increasing worldwide due to its green renewable energy and abundant sources: (a) Terangkan perbezaan di antara biofuel generasi pertama dan biofuel generasi kedua. Nyatakan satu (1) aplikasi setiap biofuel tersebut. Describe the difference between first generation biofuels and second generation biofuels. List one (1) application for each of the biofuel. (b) (c) Kenapa kehadiran Acid Lemak Bebas (FFA) di dalam proses transesterifikasi boleh mengurangkan hasil produk? Cadangkan dua (2) langkah bagi mengelakkan kesan FFA di dalam proses tersebut. Why the presence of Free Fatty Acid (FFA) in transesterification process can reduce the yield of the product? Suggest two (2) methods to prevent the effect of FFA in the process. Pirolisis merupakan sebahagian teknik gasifikasi dalam menukarkan bekas tandan buah sawit kepada banyak produk yang penting. Pyrolysis is one of the gasification methods in converting empty palm fruit bunch into many important products. (i) Apakah perbezaan di antara pirolisis perlahan dan pirolisis pantas? What is the difference between slow pyrolysis and fast pyrolysis? (1 markah/marks) (ii) Terangkan produk dan peratusan hasil yang biasa diperolehi daripada pirolisis perlahan Describe typical product and percentage yield of slow pyrolysis. (3 markah/marks) 2/8

3 (iii) Bio-oil mentah diperolehi daripada proses pirolisis perlu dipertingkatkan samada menggunakan mangkin hidrodeoksigniasi (HDO) atau zeolit. Terangkan kelebihan dan kekurangan mangkin HDO dan zeolit dalam mempertingkatkan bio-oil. Raw bio-oil obtained from the pyrolysis has to be upgraded either using hydrodeoxygenation (HDO) catalyst or zeolite. Explain the advantages and disadvantages of HDO catalyst and zeolite in bio-oil upgrading. (3 markah/marks) 2. Data dibawah menunjukkan pecahan penukaran ( x ) dengan kadar tindak balas - r A (moldm -3 s -1 ) The data below shows the fractional conversion ( x ) and rate of reaction - r A (moldm - 3 s -1 ) X - r A (moldm -3 s -1 ) /8

4 Dua reaktor diatur secara bersiri. Reaktor pertama adalah reaktor palam dan reaktor kedua adalah reaktor tanki berterusan kacauan (CSTR). Tahap penukaran dalam reaktor pertama ialah 60% dan penukaran mencapai 90% selepas keluar dari reaktor kedua. Diberi aliran suapan molar, F A0 ialah 0.80 mols -1, Two reactors are arranged in series. The first reactor is a plug flow reactor and the second reactor is continuous stirred tank reactor (CSTR). The rate of conversion in the first reactor is 60% and the conversion reaches 90% after leaving the second reactor. The volumetric feed F A0 is 0.80 mols -1. (i) Hitungkan isipadu reaktor pertama dan kedua. Calculate the volume of the first and second reactor. (7 markah/marks) (ii) (iv) Jika susunan reaktor diterbalikkan dimana reaktor pertama ialah CSTR dan diikuti dengan reactor palam, hitungkan isipadu kedua-dua reaktor. If the sequence of reactor is reversed where the first reactor is CSTR and followed by plug flow reactor, calculate the volume of both reactors. (7 marks /markah) Terangkan prestasi reaktor dalam (i) dan (ii) di atas Explain the performance of the reactors in (i) and (ii) above. (2 markah/marks) 3. (a) Terangkan kelebihan dan kekurangan reaktor mampatan padatan dasar dan reaktor tangki berterusan kacauan (CSTR)? Explain the advantages and disadvantages of packed bed reactor and continuous stirred tank reactor (CSTR)? (c) Tindak balas penghidrogenan metil dodekanoat dijalankan di dalam reaktor lelehan dasar dengan menggunakan 50 cm 3 ekstrudat 5wt%Cu-10wt% Zn/Al 2 O 3 mangkin pada suhu tindak balas 150 C, tekanan hidrogen pada 100 bar dengan halaju superfisial cecair pada 1.0 cms -1 dan kelajuan graviti bumi 9.81 ms -2. Methyl dodecanoate hydrogenation is performed in a trickle bed reactor using 50 cm 3 of extrudate 5wt%Cu-10wt%Zn/Al 2 O 3 catalyst at reaction temperature of 150 C, hydrogen pressure at 100 bar with liquid superficial velocity of 1.0 cms -1 and earth gravity speed at 9.81 ms -2. 4/8

5 (i) (ii) (iii) (iv) Lukis skematik diagram bagi kenaikan arus bersama reaktor lelehan dasar Draw a schematic diagram of co-current upward trickle bed reactor. (3 markah/marks) Hitungkan kadar aliran metil dodekanoat di dalam tiub reaktor apabila garis pusat dalaman adalah 90 mm. Calculate the flow rate of methyl dodecanoate in the reactor tube when the internal diameter is 90 mm. Hitungkan purata masa menghuni apabila panjang tiub reaktor ialah 500 cm. Calculate the mean residence time when the reactor tube is 500 cm long. Apakah perbezaan di antara halaju sejam superfisial gas (GHSV) dan halaju sejam superfisial cecair (LHSV) What is the difference between Gas Hourly Superficial Velocity (GHSV) and Liquid Hourly Superficial Velocity (LHSV) (2 markah/marks) 5/8

6 Jawab semua soalan dalam bahagian ini. Answer all questions in this section. BAHAGIAN B (50 MARKAH) SECTION B (50 MARKS) 4. Nombor Reynolds adalah nombor tanpa dimensi yang berguna untuk menentukan aliran bendalir yang mengalir di dalam paip. Untuk aliran bendalir yang tertentu, diberi nilai D = 2.5 in, = ft/s, = 0.96 g/cm 3 dan = 1.24 x 10-4 kg/ms. Tentukan sama ada aliran tersebut adalah aliran laminar atau gelora. (Given 1 m = 3.3 ft = 39.4 in). The Reynolds number is a dimensionless number useful to define a fluid flowing in a pipe. For a particular flowing fluid, given that the D = 2.5 in, = ft/s, = 0.96 g/cm 3 and = 1.24 x 10-4 kg/ms. Determine whether it is laminar or turbulent flow. (Given 1 m = 3.3 ft = 39.4 in). 5. Bincangkan perbezaan di antara proses keadaan mantap dan prosess keadaan transien. Berikan contoh bagi setiap proses tersebut. Discuss the difference between steady state process and transient process. Give an example for each process. 6. Satu produk bijirin mengandungi 55 wt % air dihasilkan pada kadar of 500 kg/h. Kemudian, produk tersebut dikeringkan sehingga kandungan air hanya tinggal 30 wt % water. Tentukan: A cereal product containing 55 wt % water is made at rate of 500 kg/h. Then the product is dried so that it contains only 30 wt % water. Determine: (a) (b) Kuantiti air yang perlu disejat per jam The water has to be evaporated per hour Amaun produk kering terhasil per jam The amount of the dried product per hour 7. Takrifkan mekanisma pemindahan haba dalam proses konduksi, konveksi dan radiasi. Define the mechanism of heat transfer in conduction, convection and radiation. (5 markah/marks) 6/8

7 8. Suhu permukaan dalaman dan luaran bagi tingkap kaca 2 m x 2 m dengan ketebalan 0.5 cm sewaktu musim dingin adalah masing-masing 10 C dan 3 C. Sekiranya nilai kekonduksian haba bagi tingkap kaca tersebut adalah 0.78 W/m C, tentukan jumlah haba yang hilang dalam kj melalui tingkap kaca tersebut pada sela masa 5 jam. Apakah pula jawapan anda sekiranya tingkap kaca tersebut berketebalan 1 cm? The temperature of inner and outer surfaces of a 0.5 cm thick and 2 m x 2 m window glass in winter are 10 C and 3 C respectively. If the thermal conductivity of the glass is 0.78 W/m C, determine the amount of heat loss in kj through the glass over a period of 5 hours. What would your answer be if the glass were 1 cm thick? 9. Nyatakan dua (2) jenis aturan aliran dalam paip penukaran haba berkembar dan berikan perbezaan antara keduanya. State two (2) types of flow arrangements in a double-pipe heat exchanger and give the differences. (8 markah/marks) 10. Satu paip penukaran haba berkembar diperbuat daripada tiub dalaman kuprum (k = 380 W/m C) dengan diameter dalaman D i = 1.2 cm dan diameter luaran D o = 1.6 cm serta tiub luaran berdiameter 3.0 cm. Nilai pemalar konveksi penukaran haba diberikan sebagai h i = 700 W/m 2 C pada permukaan dalaman tiub manakala h o = 1400 W/m 2 C pada permukaan luarannya. Bagi faktor fouling pada bahagian tube R f.i = m 2 C/W dan R f.o = m 2. C/W pada sisi tiub, tentukan: A double-pipe heat exchanger is constructed of a copper (k = 380 W/m. C) inner tube of internal diameter D i = 1.2 cm and external diameter D o = 1.6 cm and an outer tube of diameter 3.0 cm. the convection heat transfer coefficient is reported to be h i 700 W/m 2. C on the inner surface of the tube and h o = 1400 W/m 2. C on its outer surface. For a fouling factor R f.i = m 2. C/W on the tube side and R f.o = m 2. C/W on the shell side, determine: (a) Rintangan haba bagi penukaran haba tersebut terhadap panjangnya The thermal resistance of the heat exchanger per unit length 7/8

8 (b) Pemalar penukaran haba keseluruhan U i dan U o berdasarkan permukaan dalaman dan luaran tiub tersebut masing-masing The overall heat transfer coefficients U i and U o based on the inner and outer surface areas of the tube, respectively (8 markah/marks) TAMAT END 8/8