ĐỒ ÁN QUÁ TRÌNH THIẾT BỊ HẤP THỤ CO2

CONTENT Chater Economy Assoc Prof Huynh Lien Huong LIST OF FIGURE Chater Economy Assoc Prof Huynh Lien Huong LIST OF TABLE Chater Economy Assoc Prof Huynh Lien Huong LIST OF ACRONYMS Abbreviation Expansion CO2 Carbon Dioxide Chater Economy Assoc Prof Huynh Lien Huong ACKNOWLEDGE A completed study would not be done without any assistance Therefore, the author who conducted this research gratefully gives acknowledgement to their support and motivation during the time of doing this research First of all, I would like to express my endless thanks and gratefulness to my supervisor Assoc Prof Huynh Lien Huong Her kindly support and continuous advices went through the process of completion of my project Her encouragement and comments had significantly enriched and improved my work Without her motivation and instructions, the project would have been impossible to be done effectively My special thanks approve to my parents for their endless love, care and have most assistances and motivation me for the whole of my life I also would like to explain my thanks to my siblings, brothers and sisters for their support and care me all the time As last, my deeply thanks come to all my friends during time I studied this project Their kindly help, care, motivation gave me strength and lift me up all the trouble for the rest of my life Chater Economy Assoc Prof Huynh Lien Huong CHAPTER INTRODUCTION 1.1 Introduction packed column Packed columns are used for absorption, adsorption, distillation and other processes[1] The column is cylindrical; the inside is filled with cushion There are many types of cushions, the most common being the following: - Ring packed, size from 10 ÷ 100mm - Grain packed Size is from 20 ÷ 100mm - Twisted packed, size from 0.3 ÷ 1mm, diameter of coil size ÷ 8mm, length not more than 25mm - Wooden mesh packed All of the above types of packed have common requirements: - Large individual surfaces (symbol δ, dimension m2 / m3) Large free volume (symbol Vfree, dimension m2 / m3) - Small individual weight - Chemically stable In fact, there is no type of pack that meets all the above requirements, so depending on the specific conditions, choose the appropriate type of cushion Packed column has the following advantages: - Having large, high efficiency phase contact surface - Simple structure - The resistance in the column is not very large - The working limit is relatively wide However, the disadvantage of the packed column is that it is difficult to evenly wet the mattress[2] Therefore, if the column is too tall, the liquid is not evenly distributed Therefore, one had to split the floor and put a liquid dispenser on each floor 1.2 Introduction carbon dioxide: 1.2.1 Properties of Carbon dioxide (CO2) Carbon dioxide (chemical formula CO2) is a colorless gas with a density about 53% higher than that of dry air[3] Carbon dioxide molecules consist of a carbon atom covalently double bonded to two Chater Economy Assoc Prof Huynh Lien Huong oxygen atoms It occurs naturally in Earth's atmosphere as a trace gas The current concentration is about 0.04% (412 ppm) by volume, having risen from pre-industrial levels of 280 ppm Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, ice caps, glaciers and seawater It is present in deposits of petroleum and natural gas Table 1-1 Properties of CO2 gas Properties Density • • Solubility in water 1562 kg/m3 (solid at atm and −78.5 °C) • 1101 kg/m (liquid at saturation −37 °C) 1.977 kg/m3 (gas at atm and °C) 1,45 g/L at 25C Melting point -57C Sublimation -78C Acidity (pKa) 6.35, 10.33 Vapor pressure 5.73 MPa (20C) Viscosity 0.07 Cp -78C Chater Economy Assoc Prof Huynh Lien Huong - Carbon dioxide is soluble in water and react with base, base oxide and salt 1.2.2 Production carbon dioxide (CO2) - CO2 appear in the burned process organic material - Carbon dioxide is a by-product of the fermentation of sugar in the brewing of beer, whisky and other alcoholic beverages and in the production of bioethanol Carbon dioxide is a byproduct of the industrial production of hydrogen by steam reforming and the water gas shift reaction in ammonia production • • - 1.2.3 Effect of carbon dioxide in environment and human - Environment: Carbon dioxide contributes to air pollution in its role in the greenhouse effect Carbon dioxide traps radiation at ground level, creating ground-level ozone[3] This atmospheric layer prevents the earth from cooling at night One result is a warming of ocean waters Oceans absorb carbon dioxide from the atmosphere However, higher water temperatures compromise the oceans' ability to absorb carbon dioxide Over time, the effects of carbon dioxide are compounded - Human: The concentration of CO2 in the air is 0.004% If this concentration is higher than this value, Carbon dioxide emissions impact human health by displacing oxygen in the atmosphere Breathing becomes more difficult as carbon dioxide levels rise In closed areas, high levels of carbon dioxide can lead to health complaints such as headaches Carbon dioxide levels may indicate high levels of other harmful air pollutants such as volatile organic compounds which contribute to indoor air pollution 1.3 Methods of treatment of CO2 1.3.1 Absorbs CO2 gas with water Absorption of CO2 gas by water is one of the simplest methods applied earliest to remove CO2 in exhaust gas, especially in the exhaust fumes of industrial furnaces[4] Chater Economy Assoc Prof Huynh Lien Huong The CO2 water treatment system consists of phases: - Absorbs CO2-containing flue gas by spraying water into the flue gas stream or passing the exhaust gas through a layer of watering buffer (hollow material) - scrub[5] - Release CO2 gas from absorbent to reuse clean water and recover CO2 (if necessary) Dissolved concentration of CO2 in water decreases as the water temperature increases, so the temperature of the water supplied to the system used to absorb CO2 must be low enough In order to reuse water, to release CO2 gas from the water, the temperature of the water must be high Specifically, when at a temperature of 100 ° C, CO2 evaporates completely and in the escape gas stream there will be water vapor And by condensation method, CO2 gas with very high concentration will be obtained for use in sulfuric acid production purpose A theoretical equal amount of water is required to absorb 1ton CO2 to saturation with different temperature and CO2 concentrations in the exhaust gas From the aforementioned disadvantages, this method of absorbing CO2 with water is only applicable when: - Initial concentration of the exhaust gas has a relatively high concentration of CO2; - When a cheap heat source (steam) is available; - When cold water is available; 1.3.2 CO2 gas treatment with limestone The absorption and treatment method of CO2-containing exhaust gas is as follows: The exhaust gas passes through the bottom-up absorption column treatment system, in which pollutants such as CO2 and dirt are trapped, the clean air goes up and out Absorbent solution (usually Ca(OH)2) is pumped by the duct system, circulating pumped on the upper part of the cylinder body and sprayed by a mist system, evenly irrigated with the absorbent in the column The gas flows from the bottom up, the liquid flows from the top down and they touch each other, then the absorption process takes place, CO2 is trapped in the absorbing solution, the clean air escapes Chater Economy Assoc Prof Huynh Lien Huong 2CO2 + Ca(OH)2 → Ca(HCO3)2 Ca(HCO3)2 + Ca(OH)2 → 2CaCO3 + 2H2O CaCO3 is a low solubility solid, so it is easily deposited to the bottom of the column and is treated by burial Clean air at the top of the column is dehumidified, then released into the environment 1.4 Process technology Figure 1-1 Technology process Select the source of raw material is the exhaust gas from thermal power plants The pre-treated gas reduces the temperature of the gas coming out of the tube and filters the dust before treating it with an absorption device 10 Chater Economy Assoc Prof Huynh Lien Huong t = 2.5 (mm): Thickness of distributor Total mass of equipment: Total allowable load of equipment: Choose the tower with legs and lug, the material of both are CT3 steel 2.14.2 Leg support: The leg support are placed on concrete floors of grades 65 and 90, so the allowable load of the supporting surface < (N.mm-2) on factory (2, table XIII.34, p.436[6]) We choose type IV leg type because due to the number of legs selected> and welded to the body, there must be a pad to increase the stiffness in the welded body with the foot at the bottom of the device Figure 2-8 Data of leg support Allowable load per a leg support: 42 Chater Economy Assoc Prof Huynh Lien Huong (Table XIII.35 p 437 sổ tay QTTB ,2) G.10 -4 F.10 (m2) (N) q.106 (N/m L B B1 B2 H h s l d Dt/A ) mm 2.5 444 0.56 250 180 215 290 350 185 16 90 27 1500/550 Table 2-10 Data of leg support 2.14.3 Lug support: Solder lug support and pads to increase stiffness, choose a style VIII (2, Fig XIII.21, p.436[6]) 43 Chater Economy Assoc Prof Huynh Lien Huong Figure 2-9 Lug support (2, table XIII.36, p.438) Table 2-11 Data of lug support G.10-4 F.104 q.106 (N) (m2) (N/m2) 2.5 173 L B B1 H S l d 1.45 a mm 150 120 130 215 Table 2-12 Data of pads: 44 60 30 20 Chater Ancillary equipment CHAPTER G.10-4 (N) Assoc Prof Huynh Lien Huong Minimum thickness of pads A B H SH N C mm I 2,5 120 215 L L ARY EQUIPMENT CALCULATION 3.1 Cyclone Figure 3-10 Cyclone Flowrate of CO2 gas: Q = 300m3/h = 0.083 m3/s Veclocity of gas in chimney: v = 1.134m/s The diameter of gas pipe: 0.08(m) The cross-section of cyclone where the gas is go in: Chater Ancillary equipment Assoc Prof Huynh Lien Huong Minimum particle diameter: μm (the diameter that all particle sizes equal to or larger than this size will be retained by cyclone) Figure 3-11 Size of cyclone S = 0.5D × 0.2 D = 0.031( m2 )  The diameter of cyclone: D = 0.556 (m) Diameter of center: D2 = 0.5D = 0.278 (m) The height of cyclone Hc = 4D = 2.224 (m) The area surface of cyclone: The area of gas oultet: So As = π × D2 × (1.5 + 2.5) = 3.88 ( m2 ) ( 0.5 × D ) =π× = 0.06 ( m2 ) Velocity outlet cyclone of gas: Table 3-13 Filtration efficiency according to the particle size of the centrifugal cyclone Diameter of particles (μm) 10 15 20 25 >25 Chater Ancillary equipment Filtration efficiency (%) Assoc Prof Huynh Lien Huong 26.2 52.1 78.6 100 100 3.2 Elevated tank Diameter of pipe: mm Pipe roughness: mm (Fig II.14, p 380,1) o C - Density: kg.m-3 (table I.2, page 9,1) - Kinetic viscosity: N.s-1.m-2 (table I.101, page 91, 1[9]) Average velocity of feed pipe: (m.s-1) Head loss of pipe  l1  v12 h1 =  λ + ∑ ξ ÷ ×  dF  2g Where - λ : friction coefficient - l1 : length of pipe, l1 = 15 m - d F : diameter of pipe (m) - ∑ ξ : total minor loss (m) (5-60) Chater Ancillary equipment - Assoc Prof Huynh Lien Huong vF = v1 : velocity of feed on pipe, m.s Calculate -1 λ 1: Reynolds of feed on pipe: (II.60, p378, 1) Reynolds at the onset of roughness: (II.61, p 378, 1) → Re gh < ReF < Ren1 : Turbulence flow: (II.64, p 380, 1) Calculate ∑ ξ1: - curve : - valve: ξ u1 = 3.0,11 = 0,33 (p393, 1) ξ v1 = 3.10 = 30 - completely open: ξ thu = 0,5 (page 387, [9]) - completely close: ξ m = (page 387, [9]) - flowmeter: none Chater Ancillary equipment → Assoc Prof Huynh Lien Huong ∑ ξ = 31,83 Head loss: (m) - P1 : air pressure (1 – 1), P1 = at - P2 : pressure of (2 – 2) site - v1 : velocity (1 – 1) site, v1 = m.s - v2 : velocity in feed site, v2 = vF = 0,125 m.s - ∑ h f − : head loss from (1 – 1) to (2 – 2) -1 -1 (N.m-2) Elevated tank’s height: P2 − P1 v22 − v12 H cv = z2 + + + ∑ h f 1− ρ F g 2.g (m) 3.3 Pump efficiency Based on the characteristics of low pressure, the pump we choose is a centrifugal pump.(Sổ tay QTTB ,1 ,p493[9]) Pump efficiency: Where Chater Ancillary equipment Assoc Prof Huynh Lien Huong Q: Flowrate of inlet liquid, H: pump head height → H = H t + = + = 10 (mH O) với H heigth of column t : pump yields (table II.32, p.439 sổ tay QTTB ,1) η0 Pittong pump Centrifugal pump Vortex pump Notched tooth pump η ck η tl 0,8 – 0,94 0,9 – 0,95 0,85 – 0,96 0,8 – 0,85 0,95 – 0,96 > 0,8 > 0,7 > 0,9 0,7 – 0,9 Table 3-14 Pump yield Table 3-15 Reserve coefficient table → Ndc β 50 1,1 Chater Ancillary equipment Assoc Prof Huynh Lien Huong Pump efficiency: Select pump efficiency 10 Hp 3.4 Compressor efficiency Choose centrifugal compressor working on low pressure (2 – 10 at) Compressor efficiency: Isothermal : (J/kg) (2, II.242, p.465) (N/m2) atmosphere pressure working pressure from bottom to top equipment specific volumn of vapor before compress Theoretical capacity: (kg/s) Realty capacity: Where mechanic efficiency kinetic eficiency electric efficiency Choose Hp compressor Chater Ancillary equipment Assoc Prof Huynh Lien Huong Chater Ancillary equipment Assoc Prof Huynh Lien Huong CHAPTER ECONOMY Table 4-16 Implementation cost calculation table Name types quantities unit Cost X18H10T Kg 1500 70.000 105.000.000 CT3 Kg 300 15.000đ 45.000.000 M20 50 6.100 305.000 M16 100 4.070 407.000 M10 36 1.200 43.200 P50 35.850 2.300 82.432.000 Bolts Rasiga ring packed Total material 233.187.000 Fabrication cost 22.000.000 Liquid flow meter 750.000 750.000 Vapor flow meter 500.000 500.000 10 Hp 58.660.000 4.020.000 Hp 2.400.000 2.400.000 m 30 30.000 900.000 Pump Compressor Steel pipe Chater Ancillary equipment PVC pipe Valve Technology cost Total Assoc Prof Huynh Lien Huong m 30 5.900 177.000 50 000 150.000 8.020.000 283.000.000 Chater Ancillary equipment Assoc Prof Huynh Lien Huong CHAPTER CONCLUSION The process consumes a lot of solvents, so it is still not economical It is recommended to change the solvent and absorbent column type or can investigate more CO2 absorption methods to compare absorption efficiency and economy Advantages: - Simple structure, easy to operate - Solvent is cheap, easy to find, non-toxic - Works well in corrosive environments Disadvantages: - Low productivity - The gas before entering the tower must be cooled down and pretreated - Clean water is required to avoid creating residue during absorption REFERRENCE [1] W.K Lewis, W.G Whitman, Principles of gas absorption, Industrial & Engineering Chemistry 16(12) (1924) 1215-1220 [2] E Brunazzi, G Nardini, A Paglianti, An economical criterion for packed absorption column design, Chemical and biochemical engineering quarterly 16(4) (2002) 199-206 [3] M Aresta, Carbon dioxide as chemical feedstock, John Wiley & Sons2010 [4] U Desideri, A Paolucci, Performance modelling of a carbon dioxide removal system for power plants, Energy Conversion and Management 40(18) (1999) 18991915 [5] E Worrell, L Price, N Martin, C Hendriks, L.O Meida, Carbon dioxide emissions from the global cement industry, Annual review of energy and the environment 26(1) (2001) 303-329 [6] T.Xoa, N.T.Khuong, P.X.Toan, Sổ tay trình thiết bị 2, 2005 [7] V.B.Minh, H.M.Nam, Qúa trình thiết bị cơng nghệ hóa học thực phẩm 2, 2015 [8] V.V.Bang, V.B.Minh, Qúa trình thiết bị cơng nghệ hóa học thực phẩm 3, 2015 [9] T.Xoa, N.T.Khuong, H.L.Vien, Sổ tay trình thiết bị 1, 2006 ... trình thiết bị hóa chất, 1[9]) 2.3.2 Liquid phase Viscosity: (Equation I.12 page 84 Sổ tay trình thiết bị cơng nghệ hóa học,1[9]) Where : viscosity of CO2, water at 29oC (Table I.102 Sổ tay trình. .. (Diagram I.1 page Sổ tay trình thiết bị cơng nghệ hóa chất, 1[9]) Average weight of CO2 in liquid phase: Volumetric of air in column: (Equation IX.101 page 183 Sổ tay trình thiết bị cơng nghệ hóa chất,2[6])... IX.1 page139 Sổ tay trình thiết bị cơng nghệ hóa chất ,2[6]) 13 Chater Economy Assoc Prof Huynh Lien Huong Operating line equation (do ) (Equation IX.6 page 140 Q trình thiết bị cơng nghệ hóa học