Carbon dioxide removal in indirect gasification - SGC

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SGC Rapport 2013:277 For the building of an accurate gas separation model, a number of fundamental physical and chemical data is required. For the physical properties of the system - such as density, viscosity, surface tension, diffusivity of the amines in water solution, diffusivity of gases in the amine solution, gas solubility in the amine solution and heat capacity - data was taken from the literature [41, 55-69]. However, only one journal publication on the heat of reaction for the investigated system was found with very limited data [70]. The only other reference found was an interim report from North Carolina State University [71]. For this reason an investigation on the heat of reaction for the system was conducted for the MDEA/PZ-system [72]. The data acquired from this investigation was used in the simulation model. In order to perform the calculations on the absorber and the stripper, integral balances for each unit have to be solved prior to the differential balances. For the calculation on the absorber the principle for the simulation model is as follows. The integral balances for the absorption tower give the flow rates of the incoming and outgoing gas and liquid streams, as well as the incoming and outgoing temperatures of the gas and liquid, according to Figure 20. The incoming gas flow is given by the previous steps. From the integral balances the diameter required for the absorption column can be determined, as well as the pressure drop over the column. Figure 20. System boundary, gas flows, liquid flows and temperature used for the integral balances. For the differential calculations the principle of the model is illustrated in Figure 21. Data from the literature has been used for the differential calculations for the absorber [53, 73-76]. The calculations start at the top of the absorption tower, i.e. for the outgoing gas and incoming liquid flow. The calculations are performed within a given column volume, given by the height, dh. This height is then added to the total height of the column for each calculation step (h = h + dh), as the calculations proceed. The size of the step should be small enough to ensure that the temperature for the previous step does not differ significantly from that of the current step. Mass and energy balances are solved for each step, giving the concentration and 42 Svenskt Gastekniskt Center AB, Malmö – www.sgc.se
SGC Rapport 2013:277 temperature profile over the column as a function of column height. The calculation is terminated when the CO2 concentration of the gas in the calculationelement, G(n), is the same as the concentration of CO2 in the incoming gas stream, G1. Figure 21. Calculation principle for the differential balances. All concentrations and temperatures are determined for each element, with height dh. A simple kinetic model was used to describe the reactions of CO2 with MDEA and PZ, see equation D and E. ܥܱ ଶ + ܼܲ ∙ ܪ ଶܱ ↔ ܼܲܪ ା + ܪܥܱ ଷ ି Eq. D ܥܱ ଶ + ܯ ܦܧܣ ∙ ܪ ଶܱ ↔ ܯ ܦܧܣܪ ା + ܪܥܱ ଷ ି Eq. E The model is a reduced version of that developed by Zhang et al., [77], and consists of two reactions describing the reaction of CO2 with PZ and MDEA respectively. The values for the equilibrium (ki) and rate constants (Ki) for these reactions were taken from the literature and the relationships are given by equations F-I, [78, 79]. ݇ ௉௓ = 53700 ∙ ݁ ൬ିయయలబబ ݇ ெ ஽ா஺ = 15.584 − ଷଽ଼ସ ் ఴ.యభర ∙ቀభ భ ି ೅ మవఴ.భఱ ቁ൰ ܭ௉௓ = ௘ቀమయభ.రషభమబవమ ೅ షయల.ళఴ∙ౢ౤(೅)ቁ ௘ ቀషభభ.వభషరఱయభ ೅ ቁ Eq. F Eq. G Eq. H Svenskt Gastekniskt Center AB, Malmö – www.sgc.se 43
Page 1 and 2: SGC Rapport 2013:277 Carbon dioxide
Page 3 and 4: CARBON DIOXIDE REMOVAL IN INDIRECT
Page 5 and 6: SGC Rapport 2013:277 Svenskt Gastek
Page 7 and 8: Authors’ foreword SGC Rapport 201
Page 9 and 10: Sammanfattning SGC Rapport 2013:277
Page 11 and 12: SGC Rapport 2013:277 Figur S.2b San
Page 13 and 14: SGC Rapport 2013:277 4.2.3 Chilled
Page 15 and 16: SGC Rapport 2013:277 2 Production o
Page 17 and 18: SGC Rapport 2013:277 Figure 1. Hald
Page 19 and 20: SGC Rapport 2013:277 Table 1. Summa
Page 21 and 22: SGC Rapport 2013:277 Figure 3. Sche
Page 23 and 24: SGC Rapport 2013:277 This category
Page 25 and 26: SGC Rapport 2013:277 3.1.3 Entraine
Page 27 and 28: SGC Rapport 2013:277 3.2 Gas impuri
Page 29 and 30: SGC Rapport 2013:277 of tar removal
Page 31 and 32: SGC Rapport 2013:277 Figure 11. Pos
Page 33 and 34: SGC Rapport 2013:277 4 CO2-capture
Page 35 and 36: SGC Rapport 2013:277 saturated with
Page 37 and 38: SGC Rapport 2013:277 The use of a p
Page 39 and 40: SGC Rapport 2013:277 brane systems
Page 41 and 42: SGC Rapport 2013:277 5 Models In th
Page 43: SGC Rapport 2013:277 then saturated
Page 47 and 48: SGC Rapport 2013:277 The amount of
Page 49 and 50: SGC Rapport 2013:277 Table 6. Gas c
Page 51 and 52: SGC Rapport 2013:277 Figure 23a. MI
Page 53 and 54: SGC Rapport 2013:277 Table 10. Gas
Page 55 and 56: SGC Rapport 2013:277 Table 12. Gas
Page 57 and 58: SGC Rapport 2013:277 Table 14b. Gas
Page 59 and 60: SGC Rapport 2013:277 overall biomas
Page 61 and 62: Amount absorbed of ingoing moleflow
Page 63 and 64: SGC Rapport 2013:277 of LPG additio
Page 65 and 66: SGC Rapport 2013:277 8 Conclusions
Page 67 and 68: SGC Rapport 2013:277 10 Literature
Page 69 and 70: SGC Rapport 2013:277 40. Mumford, K
Page 71 and 72: SGC Rapport 2013:277 73. Klingspor,

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