Benzene Conversion in a Packed Bed Loaded with Biomass Char

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Benzene conversion in a packed bed loaded with biomass char particles Mario Morgalla, Leteng Lin, and Michael Strand Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.7b03236 • Publication Date (Web): 05 Dec 2017 Downloaded from http://pubs.acs.org on December 9, 2017

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Benzene conversion in a packed bed loaded with biomass char particles Mario Morgalla*, Leteng Lin, Michael Strand Department of Built Environment and Energy Technology, Linnaeus University, 351 95 Växjö, Sweden Keywords: Biomass, Gasification, Tar, Char, Aerosol

ABSTRACT

This study investigates the conversion of benzene in a packed bed containing fine char particles. Benzene and steam were simultaneously supplied to a tubular ceramic reactor that was heated electrically. Fragmented char particles were suspended and continuously supplied via a separate supply line. A packed bed of crushed alumina balls was positioned in the reactor to retain the char particles. The benzene conversion in the hot char bed was investigated by varying the bed temperature (900–1100°C), steam concentration (0–27 vol.%), and char concentration (5–50 g Nm–3). The highest conversions achieved in the experiments were approximately 75%. At comparable char concentrations, similar benzene conversions occurred at 900°C and 1000°C. Increasing the temperature to 1100°C or increasing the steam concentration reduced the benzene conversion. The results indicate that the reduced conversion was due to enhanced char

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gasification reactions at elevated temperatures and steam concentrations and thus to reduced char mass in the packed bed.

1. INTRODUCTION Biomass gasification is intended to transfer the chemical energy of a liquid or solid to a gas (product gas) usable for power generation in energy conversion devices such as turbines, internal combustion engines, and fuel cells. The product gas can also be upgraded to synthesis gas, which can be used to produce various synthetic gaseous and liquid chemicals, such as gasoline, diesel, and methanol. Unwanted by-products formed in the initial stages of biomass gasification are tars, defined as organics produced under thermal or partial-oxidation regimes of any organic material and assumed to be mainly aromatic.1 Tars cause various technical problems (e.g., pipe plugging and process equipment fouling) and reduce the energy efficiency of the gasification process. Tar concentrations in the product gas from fluidized bed gasifiers are in the order of 1–30 g Nm–3.2 If the product gas is to be used, for example, in an IC engine or for methanol synthesis, tar concentrations must not exceed 100 or 0.1 mg m–3, respectively.3 Since primary measures (e.g., bed additives and gasifier modifications)4 that aim to minimize tar production in the gasifier are often insufficient, secondary measures that aim to reduce the tar concentration downstream from the gasifier are needed. The latter could include physical separation of the tars using, for example, a wet scrubber, or the thermal and catalytic conversion of the tars. Since up to 10% of the energy in the raw syngas from an indirect fluidized bed gasifier could correspond to aromatics5 (mainly benzene), the conversion, instead of physical separation, of aromatics at elevated temperatures will increase the energy efficiency of the gasification process. High tar removal efficiencies have been reported using either metal- or transition-metal-based catalysts6


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or a hot bed of biomass char.7, 8 The advantage of using biomass char is that it is continuously produced in the gasification process. This fact has been exploited in a few gasification schemes in which the produced biomass char was collected downstream from the gasifier, forming a fixed bed in order to remove nascent tars.9-11 Reducing the tar concentration using a char bed as a prereformer is advantageous since high tar concentrations increase the risk of soot formation in partial oxidation units12 and the deactivation tendency in tar-cracking catalysts.13 Tar conversion in a fixed bed of char has been intensively studied and reviewed.14 It was concluded that aromatic components, once adsorbed on the active sites of the char surface, were either steam and dry reformed into CO and H2 or decomposed to form free tar radicals that enter heavy hydrocarbon polymerization reactions, leading to the deposition of coke on the char surface.15 Hosokai et al.16 stated that the aromatics were primarily decomposed over the char to form coke rather than directly steam reformed, and that to keep the char active, the formation rate of carbon-containing gases must be kept above the rate of carbon deposition. A potential drawback of fixed char beds is the use of quite large char particles, possibly leading to external or internal mass transport limitations biasing tar conversion kinetics. Another disadvantage is the consumption (i.e., gasification) of the char in fixed beds. Recently, an aerosol-based method was designed and tested for tar conversion17 using very small and finely dispersed char particles that might avoid potential mass transport limitations. This method was also used to investigate the benzene conversion behavior while continuously supplying fresh char particles. In that way, the deactivated and gasified char particles were steadily replaced, preventing the benzene conversion from decreasing over time. However, since a surface filter was used, the pressure drop in the filter cake would only allow low char concentrations (approx. 5 g Nm–3), which were too low to permit significant benzene conversions.


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In this study, the surface filter was therefore replaced with a packed-bed-type depth filter that could handle higher particle loads. This permitted the use of char concentrations expected in the product gas of a fluidized bed gasifier (i.e., 1–40 g Nm–3).18 Since entrained char particles might deposit in partial oxidation- or auto thermal reforming units that operate at high temperatures, experiments were performed at temperatures up to 1100℃. In addition, the attainment of a steady-state char gasification process made it possible to investigate the tar conversion using extremely small amounts of char in the bed, compared with studies using a fixed bed of char. Two types of char were investigated at different char concentrations, steam concentrations, and temperatures. 2. Material and methods 2.1 Materials A granular hardwood-based steam-activated charcoal (AC), type Soil DeTOX (Charcoal House, Crawford, NE, USA), and a commercially certified (EN-1860-2) barbeque charcoal (BC) (Skandivaror, Malmö, Sweden) made from broadleaf wood were employed in the experiments. The steam-activated charcoal was manufactured at low heating rates for 4–7 h at pyrolysis temperatures of approximately 500–700°C. The elemental analysis, moisture content, and ash content of the two chars are presented in Table 1. Table 2 presents information about the internal structural properties of the two chars, determined using BET analysis (TriStar 3000; Micromeritics, Norcross, USA). To investigate the tar conversion properties of the char, benzene with a purity of 99.7% (Merck, Kenilworth, NJ, USA) was selected as the model tar compound. Benzene was chosen as the model tar since it is one of the most refractory aromatic compounds formed in the product gas from biomass gasification19, 20.


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2.2 Experimental setup The experimental setup, shown in Figure 1, consists of three main parts: 1) the char- and gassupply system, 2) the reactor, including the packed bed, and 3) the gas analysis system. 2.2.1

Char- and gassupply system

To continuously feed fresh char particles, benzene, and steam into the reactor, a char- and gassupply system was designed. In the char aerosol generator, small char particles were produced by mechanical abrasion/fragmentation. These char particles were then entrained with the carrier gas (N2) into the reactor. The char concentration was regulated by adjusting the nitrogen flow rate through the aerosol generator and the fragmentation intensity of the char aerosol generator. The gassupply system consisted of two gas supply lines, one for benzene and steam (heated to 120°C) and another for N2. The benzene concentration was regulated by adjusting the temperature of the washing bottle and the carrier gas (N2) flow rate through the washing bottle using a mass flow controller (MFC; Bronkhorst High-Tech BV, Ruurlo, Netherlands). The steam concentration was regulated by adjusting the water flow rate using a liquid mass flow controller (LMFC; Bronkhorst High-Tech) and the carrier gas (N2) flow rate using a controlled evaporation and mixing (CEM) unit (Bronkhorst High-Tech). The char and the reactive gases (i.e., steam and benzene) were fed into the reactor via separate stainless steel tubes. 2.2.2

Reactor, including the packed bed

The fragmented char particles were retained in an approximately 10-cm-long packed bed inside a ceramic reactor (Pythagoras tube; Morgan Advanced Materials, Windsor, England). The packed bed was made of Al203 balls (T-162; Almatis GmbH, Ludwigshafen, Germany), crushed into irregularly shaped particles with a particle size of 2–3 mm. The reactor and the bed material


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were heated to the desired temperatures in an electrically heated tube furnace (Entech Energiteknik AB, Ängelholm, Sweden). The gas velocity inside the empty reactor was adjusted to approximately 0.5 m s–1 at the bed temperature, assuming no chemical reactions in the reactor. This gas velocity corresponded to a gas residence time of approximately 0.05 s within the 10-cm-high Al2O3 bed, given a void fraction of 0.3 in the bed. 2.2.3

Gas analysis system

Downstream from the reactor, a high-temperature (HT) thimble filter was mounted in a metal case to collect the char particles not captured in the bed. The metal case was heated to 250°C to minimize the benzene adsorption effects of the char particles collected in the thimble filter. A Fourier transform infrared (FTIR) gas spectrometer (type DX-4000; Gasmet Technologies Oy, Helsinki, Finland) operating at 180°C was used to extract the gases and measure the steam, CO, and benzene concentrations. The gases exiting the FTIR instrument were guided to a micro gas chromatograph (model CP-4900; Varian Inc., Palo Alto, CA, USA) measuring the H2 concentration and to a CO2 meter (model CM-0001; CO2 Meter Inc., Ormond Beach, FL, USA) measuring the CO2 concentration. To adjust the gas concentrations within the limits of the measurement instruments and minimize the amount of char collected in the HT thimble filter, the inlet gases to the instruments were diluted with nitrogen. All gas concentrations were corrected for the dilution downstream from the reactor. 2.3 Experimental procedure 2.3.1

Benzene conversion experiments

The following describes the experimental procedure for determining the benzene conversion. Each experiment was initialized by establishing the baseline for the benzene conversion


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measurements, to correct for any thermal conversion in the reactor. This was accomplished by measuring the outlet gas composition at the desired temperature and steam concentration, but without any char feeding. Subsequently, the char feeding was started and char accumulated in the packed bed until a steady state was reached, i.e., the char gasification rate equaled the char feeding rate. Steady-state conditions were indicated by constant H2, CO, and CO2 concentrations. In that way, the benzene conversion effect of the char under steady-state conditions was established according to Eq. 1. The experimental parameters used are presented in Table 3. Due to experimental limitations, not all combinations of the three experimental parameters (i.e., char concentration, temperature, and steam concentration) could be investigated under steady-state conditions; for example, high char concentrations could not be combined with low temperatures, since the packed bed would become clogged before reaching steady state. In some cases, the benzene conversion was investigated before steady-state conditions were reached. In those cases, the char feeding was stopped and the char accumulated in the bed was completely gasified to establish the mass of the char residing in the bed at the end of the experiment. In this way, the benzene conversion could not be reported as a function of the char concentration, but instead as a function of the char mass (τ). This procedure is explained in more detail in section 2.3.3. The benzene conversion was calculated as: (t) =

where c'()*,+ ,

-.

and /012,3 4

,

, (!) " ,

∙ 100

(1)

are the benzene outlet concentrations measured before and

after char particle deposition started at temperature Tset, respectively. Therefore, the presented benzene conversions include neither thermal conversion effects nor the catalytic effects of ash particles left from previous experiments. The catalytic effects of ash particles that built up during


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the experiments were considered negligible and were thus not corrected for. Changes of the gas volume flow rates caused by char gasification were corrected for. 2.3.2 Char concentration determination Based on the design of the char aerosol generator, it was estimated that most of the char mass deposited inside the packed Al2O3 bed must be formed by char particles with an aerodynamic diameter ) = ?@

A@ BC 3+++

, ∙?MNO

DEF (>) + EFH (>)I − KL

BC

, T?U PRS , ?MNO ∙3+++∙A@

P Q1 − L

(2)

where VW (g mol–1) represents the molar mass of carbon, X? (L mol–1) the molar volume of an

ideal gas at NTP (i.e., 20°C and 1 bar), YW the mass fraction of carbon in the char, C'()*,+ , the

benzene concentration at NTP, and y[\ and y[\H the gas concentrations (ppm) of CO and CO2, respectively. Observe that the calculated char concentration includes only the fraction of char particles collected inside the packed bed, not the fraction that passes through the reactor without contributing significantly to the conversion. 2.3.3 Weight time (τ) determination Since the volumetric flow rate was kept constant during the experiments and the mass of

catalyst (i.e., char) was changed, the weight time, ] [_` ℎ ab ] (defined as the ratio of the mass ACS Paragon Plus Environment

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of char in the bed to the gas volume flow rate), was used instead of the residence time/space velocity. The mass of char in the bed was estimated by stopping the char supply at the end of each experiment and allowing the deposited material in the bed to be fully gasified, while establishing the total carbon released as CO and CO2 during the conversion. The weight time was calculated according to Eq. 3: ] =

d@efg h

!p ?U ∙h j ∙ kUl (!)mkUlH (!)∆!

= 3+++ ∑+ 3

A@ Bo h

(3)

where aqrs [_`] represents the mass of char in the packed bed, t u [ab ℎ3 ] the gas volume

flow rate at room temperature, t [ab ℎ3 ] the gas volume flow at the bed temperature, vw0! , and

∆t [h] and t x [h] represent the time interval between two data points and the time applied for char

gasification, respectively. 2.4 Tar kinetics Assuming plug flow conditions and no influence of the steam concentration (high excess) on the benzene conversion during the experiments, the description of the benzene conversion rate over the char particles was simplified to a pseudo first-order reaction with respect to the benzene concentration. In that way, the reaction rate constant, k [mb kg -3 h-3 ], was obtained according to Eq. 4: k=

-}) (3-~)

(4)

where X represents the benzene conversion. This approach has been widely accepted21-23 and permits comparison of catalyst activities in tar elimination based on the apparent first-order rate constant, k. Rearranging Eq. 4 for the benzene conversion gives: X = 1-exp (-k ∙ τ) ∙ 100

(5)


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To present the benzene conversion as a function of the char concentration, :ℎ< =1 , Eq. 5 was modified to: X = L1 − exp D

∙[ ∙j 3+++

IP ∙ 100

(6)

where t ' [h] represents the characteristic contact time between benzene and char, which is expected to be changed by the temperature and steam concentration, but not by the char concentration.

3. Results and discussion 3.1 Influence of temperature and steam concentration Figure 2 shows the benzene conversions for BC at (a) 900°C and (b) 1100°C using low (13.5 vol.%) and high (27 vol.%) steam concentrations; the results for AC are not presented because they are similar. The data presented in Figure 2 were obtained in two separate experiments and illustrate typical raw datasets compiled to establish the influence of char concentration and temperature on the benzene conversion, as presented in sections 3.2 and 3.3. Note that Figure 2 does not cover the initial char build-up phase or the final char gasification phase. As obvious from Figure 2, at both temperatures, increasing the steam concentration led to a slightly higher CO2 and slightly lower CO concentration, related to a more pronounced water– gas-shift reaction. The H2 concentration did not change substantially at higher steam concentrations because the H2 concentration was determined mainly by the steady-state char gasification, which did not change in the long term with increasing steam concentrations. Increasing the steam concentration led to a decrease in the benzene conversion at 900°C and 1100°C. At 900°C, the benzene conversion declined from 18% to 12% as the steam concentration increased from 13.5 vol.% to 27 vol.%. Increasing the steam concentration at


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1100°C lowered the benzene conversion from approximately 55% to 25%. The lower benzene conversions at higher steam concentrations were explained by the establishment of a new steady state with less char (aWqrs ) in the packed bed. In the transient period between both steady states, the amount of char in the packed bed was reduced by the accelerated gasification reaction, indicated by the blue curve in the figure. It has been reported16 that in the absence of a gasifying medium, char will be deactivated due to coke formation. It was therefore of interest to investigate whether this would also be the case if fresh char particles were supplied continuously. Figure 3 shows the CO, CO2, and H2 concentrations and benzene conversion in the absence of steam. Since no steady state of the char gasification is expected without steam, data are shown from the point of initiating the char feeding. When AC (Figure 3a) was used, the benzene conversion initially increased for approximately 8 min until it reached 40%, after which it remained constant, even though the amount of char in the bed was expected to increase continuously. It has been reported22, 24 that coke formed during the conversion of aromatics might deactivate the char in the absence of steam. The behavior shown in Figure 3a is probably because the char continuously collecting in the filter gradually became deactivated until the deactivated char and the supply of fresh char were finally balanced, leading to constant benzene conversion. In contrast to the high conversion when using AC, almost no benzene conversion (10–1 kg h m–3 and temperatures of 850–900°C, more than 98% of the benzene was converted. Benzene conversions as a function of char concentration (:ℎ< =1 ) are shown in Figure 8 (only the data from steady-state conditions are included). The experimental data were used to fit Eq. 6, where > u was determined to be 0.01 h and 0.003 h at 1000°C and 1100°C, respectively. The > u at 900°C could not be established due to the limited

dataset. Figure 8 suggests that at similar char concentrations, increasing the temperature from 900°C to 1100°C led to reduced benzene conversion. As discussed in section 3.2, this can be explained by the combined effect of increased char gasification reactions reducing the amount of char in the packed bed, and the increased specific benzene conversion rate at higher temperatures.


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4. Conclusions The benzene conversion during the continuous supply of finely dispersed char particles into a packed Al2O3 bed was studied using two different chars at temperatures of 900–1100°C, steam concentrations of 0–27 vol.%, and char concentrations of 5–50 g Nm–3. The higher the supplied char concentration, the higher the benzene conversion. Increasing the temperature from 900°C to 1000°C showed similar benzene conversion, while further increasing the temperature to 1100°C or increasing the steam concentration led to decreasing benzene conversions. This was probably due to the enhanced char gasification at elevated temperatures and steam concentrations, which reduced the total char mass in the packed bed, i.e., the weight time. The faster benzene conversion kinetics at elevated temperatures therefore must have been mitigated by reduced char mass. In the absence of steam, deposited non-activated BC particles did not substantially enhance the benzene conversion. However, AC particles converted the benzene even in the absence of steam, probably due to their earlier steam activation and thus higher microporous surface area compared with that of BC.

AUTHOR INFORMATION Corresponding Author * E-mail address: [email protected] Notes The authors declare no competing financial interest. ACKNOWLEDGMENT


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The financial support provided by the Swedish Energy Agency and the Swedish Gasification Centre is gratefully acknowledged.

REFERENCES 1.

Milne, T. A.; Evans, R. J.; Abatzoglou, N. Biomass gasifier tars: Their nature, formation

and conversion; NREL/TP-570-25357; National Renewable Energy Laboratory (NREL): Golden (Colorado), 1998. 2.

Graham, R. G.; Bain, R.; group, I. b. g. w. Biomass gasification hot-gas clean-up;

International Energy Agency Biomass Gasification Working Group from Ensyn Technologies and the National Renewable Energy Laboratory: Golden, CO, 1993. 3.

Woolcock, P. J.; Brown, R. C. Biomass Bioenergy 2013, 52, (0), 54-84.

4.

Devi, L.; Ptasinski, K. J.; Janssen, F. J. J. G. Biomass Bioenergy 2003, 24, (2), 125-140.

5.

Haro, P.; Johnsson, F.; Thunman, H. Energy 2016, 101, 380-389.

6.

Shen, Y.; Yoshikawa, K. Renew Sustain Energy Rev 2013, 21, 371-392.

7.

Song, Y.; Wang, Y.; Hu, X.; Hu, S.; Xiang, J.; Zhang, L.; Zhang, S.; Min, Z.; Li, C.-Z.

Fuel 2014, 122, 60-66. 8.

Ekström, C.; Lindman, N.; Pettersson, R., Catalytic conversion of Tars, Carbon black and

Methane from Pyrolysis/Gasification of Biomass. In Fundamentals of thermochemical biomass


16

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conversion, Overend, R. P.; Milne, T. A.; Mudge, L. K., Eds. Elsevier: London, 1985; pp 601618. 9.

Henriksen, U.; Ahrenfeldt, J.; Jensen, T. K.; Gøbel, B.; Bentzen, J. D.; Hindsgaul, C.;

Sørensen, L. H. Energy 2006, 31, (10–11), 1542-1553. 10. Brandt, P.; Larsen, E.; Henriksen, U. B. Energy Fuels 2000, 14, (4), 816-819. 11. Nilsson, S.; Gómez-Barea, A.; Fuentes-Cano, D.; Ollero, P. Fuel 2012, 97, 730-740. 12. Svensson, H.; Tunå, P.; Hulteberg, C.; Brandin, J. Fuel 2013, 106, 271-278. 13. Bain, R. L.; Dayton, D. C.; Carpenter, D. L.; Czernik, S. R.; Feik, C. J.; French, R. J.; Magrini-Bair, K. A.; Phillips, S. D. Ind. Eng. Chem. Res. 2005, 44, (21), 7945-7956. 14. Shen, Y. Renew Sustain Energy Rev 2015, 43, (0), 281-295. 15. El-Rub, Z. A. Biomass char as an in-situ catalyst for tar removal in gasification systems. Doctoral thesis, Twente University, Enschede, The Netherlands, 2008. 16. Hosokai, S.; Kumabe, K.; Ohshita, M.; Norinaga, K.; Li, C.-Z.; Hayashi, J.-i. Fuel 2008, 87, (13–14), 2914-2922. 17. Morgalla, M.; Lin, L.; Strand, M. Energy 2017, 118, 1345-1352. 18. Meehan, P. M. Investigations into the fate and behavior of selected inorganic compounds during biomass gasification. Master thesis, Iowa State university, Ames, Iowa, 2009, Graduate Thesis and Dissertations. Paper 10713. 19. Zhang, Y.; Kajitani, S.; Ashizawa, M.; Oki, Y. Fuel 2010, 89, (2), 302-309.


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20. Jess, A. Fuel 1996, 75, (12), 1441-1448. 21. Kastner, J. R.; Mani, S.; Juneja, A. Fuel Process. Technol. 2015, 130, (0), 31-37. 22. Fuentes-Cano, D.; Gómez-Barea, A.; Nilsson, S.; Ollero, P. Chem. Eng. J. 2013, 228, (0), 1223-1233. 23. Abu El-Rub, Z.; Bramer, E. A.; Brem, G. Fuel 2008, 87, (10–11), 2243-2252. 24. Burhenne, L.; Aicher, T. Fuel Process. Technol. 2014, 127, 140-148. 25. Nestler, F.; Burhenne, L.; Amtenbrink, M. J.; Aicher, T. Fuel Process. Technol. 2016, 145, 31-41.


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Table 1. Elemental Analysis, Moisture Content, and Ash Content of the Barbecue Charcoal and Steam-activated Charcoal Content (% dw) Non-metal elements

Steam-activated charcoal

Barbecue charcoal

C

88.2

85.4

H

0.00

2.60

N

0.22

0.26

Cl

0.03

0.01

S

0.05

0.02

O (calculated)

5.00

8.50

Si

0.98

0.13

Al

0.12

0.02

Ca

1.00

0.59

K

0.39

0.20

Mg

0.10

0.11

Na

Benzene Conversion in a Packed Bed Loaded with Biomass Char

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