1. Introduction - Firenze University Press

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Concerning the regeneration step, specificlaboratory experiments were preliminarily carried out to characterize the APC residues and to investigate their capability of regeneratingthe spent absorptionsolution rich in carbonate/bicarbonate ions[].The amount of calcium phases available for the regeneration reaction was estimated as the difference between the total Ca and the Ca as CaCO3 content of the ash, and consisted mainly of Ca(OH)2 and CaClOH[]. The quite high chloride content (around22% by weight) of the ash, mainly as calcium hydroxychlorideproved to hinder the regeneration reaction. As a matter of fact, for every mole of CaOHCl, as shown in Eq. (5), only 1 mol of KOH can be produced, differently from calcium hydroxide thatallows to regenerate 2 mol of potassium hydroxide (see Eq. (3)): CaOHCl + K2CO3KCl + KOH + CaCO3 (5) Since CaOHCl is more soluble than Ca(OH)2, it is more readilyavailable for reacting with potassium carbonate than Ca(OH)2;hence an increase in the amount of ashes added to the solution produceda reduction of the efficiency of the regeneration reaction[].To improve the alkali regeneration yield, a washing pretreatmentof the APC residues was hence tested in order to remove mostof the phases responsible of decreasing the total buffering capacityof the solution. Furthermore, in order to improve the overall leaching behavior of the solidmaterial so to comply with the disposal criteria for non hazardouswaste landfilling, the effects of a second washing treatment appliedto the residues after the regeneration step were investigated. In this case, due tothe removal of part of the KOH contained in the ash, the pH of theresidues decreased, but remained still well above values indicatingsolubility control by calcite. The mobility of most of the testedcompounds (Zn, Pb, Sb, Cr and SO4 2- ) appeared anyhow to decreaseafter this latter treatment, resulting lower than the limit values fornon hazardous waste disposal[]. The appropriate operating conditions able to maximize KOH or NaOHregenerationwere defined[][], including pre- and post-washing of the residues, as reported in Table 2. The APC residues were added to the solution to be regenerated on the basis of their calcium content as Ca(OH)2, applyinga 1,2 ratio with respect to the carbonate ions content of thesolution.In this way it was possible to reach a 90% efficiency of the reaction in terms of KOH or NaOH regeneration. In addition, the solid product showed to be mainly made up by calcite and a CO2 storagecapacity of above 300 g/kg solid product was obtained.It should be noted however, that after the regeneration reaction the liquid solution must be separated from the solid product and that disregarding the type of method useda complete recovery of the solution is not possible and therefore a lower overallfinal recovery of KOH or NaOH should be anticipated. Table 2. Operating conditions selected for the regeneration step. Pre-treatment Type Washing L/S 5 l/kg Time 15 min Regeneration Ca/CO3 2- ratio 1,2 molCa/mol CO3 2- Temperature 55 °C Time 60 min Post-treatment Type Washing L/S 5 l/kg Time 15 min 189
4. Pilot plant tests In order to demonstrate the technical feasibility of the proposed process, an integrated pilot plant for CO2absorption and regeneration of the spent solution with CO2 storage was designed and built. The pilot plant is located at the research laboratory of the University of Florence hosted at the landfill site managed by one of the partnersof the UPGAS-LOWCO2 project. 4.1. Absorption pilot plant The absorption pilot plant (Figure 2 (i)) consists of a packed column where an aqueous solution of KOH or NaOH reacts with the carbon dioxide contained in the landfill gas, which is directly extracted from the landfill [][][][][]. The alkali compound aqueous solution is fed to the column top, while the landfill gas is fed to the bottom of the column. The landfill gas is extracted from a collection station in the landfill and flows into the column by means of a side channel blower. The column fillingconsistsofSulzerlaboratoryDX packing, with a diameter of80mmandoverall heightof990cm, in stainlesssteel. The column was originally designed to process about 20-25 Nm 3 /h of landfill gas and 40-60 l/h of absorbingsolution. (a) (b) (i) (ii) Fig. 2. Pictures of the pilot plant: i) absorption column; ii) regeneration reactor and its main components: a) regeneration reactor with mixer and heating jacket, b) bottom section of the reactor with filter tensioning system, c) vacuum filtration pump, d) liquid collection tank, e) control panel and f) steel frame. 4.1.1. Monitoring equipment Input and output gas flow ratesaremeasured by means of a volumetric flow meter (Fluidwell – F110) able to work in the range from 2,5 to 35 m 3 /h.Input and output volumetric gas composition is measured too by means of a portable gas analyzer (input with Geotechnical Instruments - GA 94- and output with Geotechnical Instruments-GA2000) which measures CH4and CO2by infra-red absorption and O2 by internal electro-chemical cells.Input and output differential pressure is measured by a diaphragm pressure transducer (Delta Ohm-HD 408T 100MBG) able to work in the range from -100 to +100 mbar relative to the atmospheric pressure. Atmospheric pressure is measured by means of a barometric pressure transducer (Delta Ohm HD 9908 BARO) able to work 190 (a) (b) (e) (f) (c) (d)
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Proceedings e report 90
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ECOS 2012 : the 25 th International
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Advisory Committee (Track Organizer
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The 25 th ECOS Conference 1987-2012
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VOLUME VI CONTENT VI. 1 CARBON CAPT
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-----------------------------------
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» Personal transportation energy c
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» Excess enthalpies of second gene
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VOLUME IV IV . 1 - FLUID DYNAMICS A
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» Exergy analysis and genetic algo
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» Optimal lighting control strateg
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» Stability and limit cycles in an
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PROCEEDINGS OF ECOS 2012 - THE 25 T
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Fig. 2. The exergy destruction of M
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ineffectiveness of the catalyst, in
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[ P EXmth EX SNG] ESR F where EXm
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Fuel inputkW 728221 203771 237719 3
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Not only at desined Rc (the ratio o
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4. DISCUSSION The graphic exergy an
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Figure 9(a) illustrates the energy
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Engineering Technical Conferences &
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generally there are four kinds of m
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However, even under the off-design
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Fig. 3. 600MW supercritical coal-fi
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CO2 rich loading(molCO2/molMEA) 0.4
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Net efficiency (%) 40.28 30.29 26.4
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Fig. 11. Schematic diagram of heat
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28.67%. In addition, through heat i
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Applied Thermal Engineering 2010;30
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Abstract: PROCEEDINGS OF ECOS 2012
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Fig. 1. Solution diagram of „four
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K ~ K 1 eK 1a p K 1a iK mK
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Oxygen recovery rate, % 105 95 85 7
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Calculated optimal compressor press
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The net amount of the flue gas leav
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Figure 3. Idea for lignite drying b
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Energy efficiency, % 34,00 33,00 32
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points efficiency increase related
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Figure A1b. Thermoflex flow sheet o
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Figure A3a. Thermoflex flow sheet o
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Figure A4. Thermoflex flow sheet of
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2.1. Life Cycle Assessment 2.1.1. G
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these factors. A sensitivity analys
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methane slip contributes to 13% of
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As can be seen in Fig. 5 the impact
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References [1] Eurobserv’er, The
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in which CO2 is separated from H2,
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dimensions of water droplets and wa
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Temperature (°C) 8 7 6 5 4 3 2 1 0
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4. Conclusions In the present paper
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penalty, but without separate captu
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0.5 - 0.7 kg/kg, resulting typicall
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3.3 - Utilising waste heat All exis
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4.5 - Suomusjärvi olivine deposits
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material will change from a few % t
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Fig. 5 Schematic diagram of the PFB
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8. Combined SO2 capture and CO2 min
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Fig. 10 Carbonate- (left) and sulph
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[13] Ekdahl, E., Idman, H. Statemen
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HEAT Fig. 1. Scheme and main reacti
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(raw) materials pre-heating and AS
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Fig 3- Aspen Plus® model 110
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Table 4. Elemental and XRD analysis
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the ÅA CSM route. The content of M
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moisture - 0,2237 ash - 0,0876 LHV
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2.2 CFB plant For the current momen
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The CO2 emission factor which indic
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The CO2 emission factor calculated
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Appendix A Fig A.1. Simulation mode
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(b) Fig. A.2. Simulation model of C
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Table A.1. Calculated parameters at
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References [1] Pfaff I., Oexmann J.
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with a CC installation could be avo
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2.3. Basic CHP plant indices. The b
Page 165 and 166: 3. Off-design calculations The main
Page 167 and 168: Fig. 6. CHP plant efficiency Fig. 7
Page 169 and 170: amount of steam delivered to the he
Page 171 and 172: [5] Lukowicz H., Mroncz M.: Analysi
Page 173 and 174: water removal is feasible by coolin
Page 175 and 176: Figure 2. Sketch of the suggested P
Page 177 and 178: a b Figure 5. a) Exergy balance of
Page 179 and 180: The basis of comparison of each met
Page 181 and 182: Figure 7a. Impact of S/CATR on PCU
Page 183 and 184: However, more energy duty is requir
Page 185 and 186: Abstract: PROCEEDINGS OF ECOS 2012
Page 187 and 188: 3.1. JACOBIAN-ASPEN Interface ASPEN
Page 189 and 190: Fig. 3. Triple Pressure Bottoming S
Page 191 and 192: As seen from Table 1, the mass flow
Page 193 and 194: 4. Conclusion Fig. 5. Partial Emiss
Page 195 and 196: [19] Yantovski E., Shokotov M., Sho
Page 197 and 198: investigation and the developing of
Page 199 and 200: University of L’Aquila and German
Page 201 and 202: hydrogen combustion technology at d
Page 203 and 204: eversibility of a pre-treated synth
Page 205 and 206: Fig. 1. TG curves collected for spe
Page 207 and 208: (see Fig 5). Carbon dioxide uptake
Page 209 and 210: period is reduced to the first 15 c
Page 211 and 212: CO2 capture capacity up to 150 th c
Page 213 and 214: the way for biogas utilisation is t
Page 215: projectand is described in the foll
Page 219 and 220: Concerning the absorption reaction,
Page 221 and 222: with Regeneration (AwR), consists i
Page 223 and 224: [25] Aspen Plus 2004.1. Cambridge,
Page 225 and 226: systems for fuel drying waste strea
Page 227 and 228: heated in a heat exchanger placed i
Page 229 and 230: Fig. 2. Lower heating value of fuel
Page 231 and 232: Acknowledgements The results presen
Page 233 and 234: large amount of CO2 [1,5-7]. APCr a
Page 235 and 236: N 1 i ( x x i n 1 m ) 2.3. Carbon
Page 237 and 238: DTA analysis of the untreated APCrs
Page 239 and 240: Table 4. Relative Error (%) of the
Page 241 and 242: CaO HCl CaCl H O 193kJ / mol (
Page 243 and 244: [1] M. Fernández Bertos, S.J.R. Si
Page 245 and 246: Abstract: PROCEEDINGS OF ECOS 2012
Page 247 and 248: 2. Process development 2.1. Backgro
Page 249 and 250: to dissolve the chloride salts prec
Page 251 and 252: The remaining 25% (5 ml/min) of the
Page 253 and 254: Table 6. Experimental conversions o
Page 255 and 256: p p 1 1. 5 p H 1 1. 5 2O p mi
Page 257 and 258: Calculating from the Aspen Plus mod
Page 259 and 260: [11] Mattila, H.-P., Experimental s
Page 261 and 262: Mg2SiO4(s) + 2CO2(g) →2MgCO3(s) +
Page 263 and 264: (Mg/Fe) of the mineral rock, Mg-sil
Page 265 and 266: Figure 2. Effect of Mg/Fe ratio of
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Figure 4 shows that an increase in
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Figure 5. Process flow diagram of M
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2. Only cold utility is needed belo
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extraction process at 400 °C (~ 62
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Table A2. Extraction equations and
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[13] Teir S, Kuusik R, Fogelholm CJ
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In the area of coal technologies al
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Tabel 1. Characteristics quantities
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N m eT 4a ~ T cp T4a 1 ( K
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Auxiliary power rate of ASU, % 40 4
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[8] Buhre B.J.P., Elliott L.K., She
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1.1 - Cement Manufacturing The ceme
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2. Numerical model The purpose of t
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-0.309x15.77x2 2.085x3 240x4 12.53x
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Table 4 - Results of the optimizati
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1. Define the studied system (in th
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cycle) or a lignin extraction plant
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limiting factor for the maximum siz
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Table 5. Key data for the four ener
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Global CO 2 emissions [ktonnes/yr]
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for biofuels and the investment cos
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The possibility to capture CO2 from
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[17] Berglin N, Andersson L. Proces
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Therefore NL Agency (an agency of t
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2.2.2. Pinch analysis Pinch analysi
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3. Case study 3.1. Plant and proces
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Te 1000 mp era 900 tur 800 e [°C 7
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Application of the approach led to
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The advantage of dynamic models is
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e equal at both time intervals and
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2.5. Selecting the number of TSs Se
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A) Time Slices for solar thermal en
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The first step of procedure is to p
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cTSs demand TS solar TSs 0 2 4 6 8
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In the presented paper a framework
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[5] Erdil E, Ilkan M, Egelioglu F.
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district energy network simulation
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were decreased by 10°C.All scenari
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Site 3 Heat sources Heat load Site
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3.2.2. Input data and assumptions A
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Fig.7 shows the operation forecast
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[13] TERMIS Operation User Guide, 7
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Polygeneration is a term used to de
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The increase in energy utilization
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are available for an entire year, 8
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6. Extensions to core methodology 6
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thermal storage and possible suppor
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laterites. Ore Geology Reviews, v.
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gasification [15], hybrid biomass g
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the second reactor. In this unit, s
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The variables effect was evaluated
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atio, as well as the shift-syngas f
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Fig. 4. Effect of operating tempera
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SDG has slight effect on the syngas
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[26.] Castle WF. Air separation and
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1. Introduction - Firenze University Press

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