Methane hydrogenolysis

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Chemical Engineering Science 64 (2008) 288 -- 293

Contents lists available at ScienceDirect

Chemical Engineering Science

jo ur na l ho me pa ge: w w w . e l s e v i e r . c o m / l o c a t e / c e s

Hydrodesulfurization of jet fuel by pre-saturated one-liquid-flow technology for

mobile fuel cell applications

J. Latz a, R. Peters a, J. Pasel a,, L. Datsevich b, A. Jess b

aInstitute for Energy ResearchFuel Cells (IEF-3), Forschungszentrum Julich GmbH, D-52425 Julich, GermanybDepartment of Chemical Engineering, University of Bayreuth, Universitatsstr. 30, D-95447 Bayreuth, Germany

A R T I C L E I N F O A B S T R A C T

Article history:Received 17 July 2008

Received in revised form 17 October 2008

Accepted 17 October 2008

Available online 1 November 2008

Keywords:

Desulfurization

Jet fuel

Catalysis

Chemical processes

Multiphase processes

Multiphase reactions

To prevent the catalysts in fuel cell systems from poisoning by sulfur containing substances the fuel to beused must be desulfurized to a maximum of 10 ppm of sulfur. Thereby, damage to the catalysts in the f uel

cell and the reformer can be avoided. Diesel fuel for road vehicles within the EU is already desulfurized

at the refinery. However, jet fuel is permitted to have up to 3000 ppm of sulfur. Since the hydrodesulfur-

ization process used in refineries is not suitable for mobile applications, the aim of the present work was

to develop an alternative desulfurization process for jet fuel and to determine its technical feasibility.

To this end, many processes were assessed with respect to their application in fuel cell based auxiliary

power units (APUs). Among them, hydrodesulfurization with pre-saturation was selected for detailed

investigations. Laboratory tests revealed that also syngas operation is possible without any performance

loss in comparison to operation with hydrogen. Pure hydrogen is not available in a fuel cell system

based on reforming of jet fuel. The effects of reaction temperature, operating pressure and liquid hourly

space velocity (LHSV) were investigated. Different jet fuel qualities with up to 3000ppm of sulfur were

desulfurized to a level of 1522 ppm.

Finally, the technical applicability of hydrodesulfurization with pre-saturation was demonstrated in a pilot

plant with an electrical power of 5 kW, going beyond the laboratory scale. In a 200-h experiment, a com-

mercial jet fuel with 712 ppm of sulfur was desulfurized to a maximum sulfur content of 10 ppm. Besides

this, H2S separation by stripping with air turned out to be a suitable method for APU applications. The aim

of developing a suitable process for the desulfurization of jet fuel in fuel cell APUs has thus been achieved.

2008 Elsevier Ltd. All rights reserved.

1. Introduction

Fuel cells are well suited for on-board power supply in aircraft,

ships and heavy goods vehicles. The use of fuel cell systems in air-

craft offers the possibility to simplify the aircraft layout. Important

systems in aircraft, i.e., the gas turbine powered auxiliary power unit

(APU) for electricity supply, the fuel tank inerting systemand thewa-

ter tank, can be substituted by one single system, the fuel cell system.

The waste heat of the fuel cell system can be used for ice protection.These measures reduce the consumption of jet fuel, increase aircraft

efficiency and allow the operation at low emissions. Additionally,

the costs for aircraft related investments, for aircraft maintenance

and operation can be reduced. APUs driven by conventional gas tur-

bines operate at an efficiency of about 15% on the ground (Daggett

et al., 2003), while an APU based on autothermal reforming of diesel

or gasoline in combination with a polymer electrolyte fuel cell

Corresponding author. Tel.: +49 2461615140; fax: +492461 616695.

E-mail address: [email protected] (J. Pasel).

0009-2509/$- see front matter 2008 Elsevier Ltd. All rights reserved.doi:10.1016/j.ces.2008.10.016

(PEFC) can achieve a system efficiency of up to 36%37% (Ersoz

et al., 2006;Specchia et al., 2006).

To operate the fuel cells with the fuel available on board, this

fuel is converted into a hydrogen-rich gas by a process of catalytic

reforming. Since both the catalysts in the reformer and also in the

fuel cell are deactivated by the sulfur compounds contained in the

fuel, the latter must be desulfurized to a level of a maximum content

of 10ppm of sulfur.

Whereas diesel fuel for road vehicles is already desulfurized at therefinery within the EU, jet fuel is permitted to have up to 3000 ppm

of sulfur all over the world. Consequently, on-board desulfurization

is required for the use of fuel cell APUs on aircraft.

In industrial applications, conventional hydrodesulfurization

without pre-saturation is a well-engineered process for desulfuriza-

tion of liquid fuels. In refineries, besides hydrodesulfurization only

the S-Zorb process, a novel sorption process developed by Conoco

Pillips(Gislason, 2001;Johnson et al., 2003), is used commercially.

These processes are not suitable for mobile fuel cell applications for

the following reasons:

In fuel cell APUs based on reforming pure hydrogen is not avail-

able. The syngas to be used contains only 42% (vol.) of hydrogen.
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J. Latz et al. / Chemical Engineering Science 64 (2008) 288 -- 293 289

As the hydrodesulfurization process needs a surplus of hydrogen

in the reactor, hydrogen recycling is necessary. Since the hydro-

gen content in the syngas is reduced by the hydrofining reaction,

the gas stream cannot be recycled directly. Hydrogen depletion

would negatively affect the reaction. Consequently, an additional

gas cleaning step would be required, which makes the system too

complex.

Because of vibrations and continuous variation of the position ofthe reactor in aircraft it is not possible to apply a conventional

trickle bed reactor.

The products of the gas-phase hydrodesulfurization process cannot

be used directly in the autothermal reformer, as the hydrogen

surplus in the gaseous fuel would react with air at unacceptably

high temperatures.

To desulfurize a fuel with up to 3000 ppm of sulfur to a level of a

maximum of 10 ppm, a multi-stage hydrodesulfurization process

would be needed in the case of conventional hydrodesulfurization.

Therefore a newly developed desulfurization process is needed

for this application. Various alternative methods such as adsorption,

extraction with ionic liquids, selective oxidation, and pervaporation

are discussed in the literature. A large number of these processeswere evaluated with respect to their application in fuel cell APUs. As

a result, three potentially suitable processes were selected (Peters

et al., 2008). Besides the two-step concept of fractionation or perva-

poration combined with an adsorption process, hydrodesulfurization

with pre-saturation is a very promising approach. The investigations

to evaluate this process are presented in this paper.

2. Process design

The concept of hydrodesulfurization with pre-saturation is based

on the conventional hydrodesulfurization technology. The main dif-

ference is that the required amount of hydrogen is dissolved in the

liquid fuel before the fuel enters the reactor. In contrast to a three-

phase reaction system as used in conventional trickle bed reactors,hydrodesulfurization with pre-saturation is based on only one liquid

phase besides the solid catalyst. As the diffusion of the gas into the

liquidis already complete beforeit entersthe reactor, only a marginal

hydrogen surplus is needed in the catalyst bed. Consequently, hy-

drogen recycling is not required. The process flow sheet is shown in

Fig. 1.

The feed fuel and the syngas are fed into the saturator, where the

gas is dissolved in the liquid fuel at a pressure between 20 and 70bar.

Subsequently, the fuel is heated and passed through the catalyst bed,

where the aromatic sulfur compounds are converted to hydrogen

sulfide. To separate the gases that are dissolved in the liquid fuel,

the fuel is cooled down, expanded to ambient pressure and flushed

with air or the off-gas of the catalytic burner of a fuel cell system.

This off-gas has a low oxygen concentration of less than 1% (vol.).

The H2S containing gas can be burned in the aircraft's turbine to

avoid H2S expulsion.

In contrast to conventional hydrofining, the main advantages of

this modified process are as follows:

As there is only one liquid phase in the reactor, the process is not

affected by the vibrations in a mobile system and it is not affected

by operating in various positions.

There is neither gas nor liquid recirculation. As a result, the process

is distinguished by the unsophisticated technical embodiments

and low energy demand.

Kinetic studies show that the space velocity can be increased be-

cause of better kinetics in the liquid phase reactor ( Schmitz, 2003).

The principle of hydrogenation with pre-saturation waspatented by Berlin and McCall (1963). Similar processes for the

Fig. 1. Process flow sheet of hydrodesulfurization with pre-saturation.

desulfurization of crude oil and gas oil were patented in 1959 and

1969, but no experimental results or industrial applications were

published. A detailed process description has been patented by

Datsevich and Muhkortov (1997).More detailed developments and

lab-scale experiments were published by Schmitz (2003), Schmitz

et al. (2004) and Wache et al. (2006). The desulfurization of diesel

fuel and gas oil with up to 2250ppm of sulfur on a lab scale is

described. The process was only operated with pure hydrogen and

the product sulfur level was significantly higher than 10 ppm.

Further investigations were needed to apply this process for mo-

bile fuel cell systems operated with jet fuel:

The system must be able to desulfurize jet fuel with up to

3000ppm of sulfur to a level of 10 ppm.

The system must be able to work with syngas instead of pure

hydrogen, as no pure hydrogen is available in the APU system.

The ability to operate in mobile applications in various positions

has to be demonstrated.

A process upscale is needed to show that the process is technically

feasible.

In order to verify the technical applicability of fuel cell APUs, the

process was first investigated on a laboratory scale and then on a

pilot-plant scale.

3. Experimental section

A commercial CoMo-Hydrofining catalyst in extrudate form was

used for the experiments (Sudchemie C20-6). The average particle

size of the catalyst was 1.7 mm. The reformer syngas was used as

the hydrogen supply for hydrogenation. The syngas composition is

shown inTable 1.

For the experiments different jet fuel qualities were used, as

shown inTable 2.The first fuel was a commercial Jet A-1, which was

provided by Total Deutschland GmbH at Aachen-Merzbruck Airport

in Germany. The fuel contained 712ppm of sulfur, which is a typical

value for commercial jet fuel in the EU. The fuel with the highest

sulfur content available (called Jet Fuel HS) was a kerosene fraction

from the Spergau refinery in Germany, which was diverted from the

fuel stream before the desulfurization step. This fuel was producedfrom crude oil from Russia. As the sulfur content of 1675 ppm is still


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290 J. Latz et al. / Chemical Engineering Science 64 (2008) 288-- 293

below the maximum sulfur level of 3000ppm, sulfur compounds

were added to achieve experimental fuels with a sulfur content of

2025 ppm (Jet Fuel HS 2000) and 3031 ppm (Jet A-1 3000). The com-

position of sulfur compounds, the aromatic content and the density

of the fuels is shown in Table 2.

The first experiments were conducted on a lab scale while a pilot

plant was subsequently used to prove that the process was tech-

nically feasible. The lab-scale experiments were conducted with afixed-bed reactor with an inner diameter of 4 mm and a catalyst bed

500 mm in length. For the pilot plant a fixed-bed reactor with an

inner diameter of 64 mm and a length of 933 mm was used.

In comparison to the lab-scale test stand that does not include

H2S separation, for the pilot plant an additional stripper was used

to separate the dissolved gases from the product stream to achieve

a product with a maximum sulfur level of 10 ppm. The flow sheet of

both test facilities is shown inFig. 2.

3.1. Experimental procedure

At first the fuel and the syngas are going through the saturation

system (1) and (2) to dissolve the gas in the fuel. Subsequently, the

fuel is preheated (3) and passes the catalyst bed (4) under the partic-ular conditions that are defined by operating pressure (pR), reaction

Table 1

Syngas composition.

Concentration/% (vol.)

Hydrogen 41.0

Nitrogen 38.0

Carbon dioxide 20.0

Carbon monoxide 1.0

Table 2

Density and composition of the jet fuel samples used for the experimental investigations.

Unit Jet A-1 Jet Fuel HS Jet Fuel HS 2000 Jet A-1 3000

Density kg/m3 800.6 802.5 799.7 800.6

Total aromatics % (mass) 20.2 20.7 20.0 20.2

Sulfur content

C2+C3-thiophene ppm 182 612 595 363

Benzothiophene ppm 12 36 39 299

C1-benzothiophene ppm 150 453 527 728



Dibenzothiophene ppm 3 6

Overall sulfur content ppm 712 1675 2025 3031

Fig. 2. Flow sheet of the hydrodesulfurization process with pre-saturation.

temperature (TR) and the liquid hourly space velocity (LHSV). The

duration of each experiment, in which a set of reaction parameters

(constantp, Tand LHSV) was tested was 99.5 h. The sulfur content

in the product was measured every 24 h. It was observed during the

whole 99.5 h on stream, that the fluctuations in the sulfur content

of the desulfurized product were very small (in the range of a few

ppm). The quality of the desulfurized product was found to be good

enough to be used in the reformer and in the fuel cell.A Mitsubishi TS-100 total sulfur analyzer with a detection limit

of 0.5 ppm was used to measure the total sulfur content in the fuel.

To determine the content of the individual sulfur compounds an S-

sensitive gas chromatograph with a pulsed flame photometric de-

tector (PDPF) was used (GC Varian CP-3800). As in the lab-scale test

bench, no hydrogen sulfide separation unit was integrated, and the

product samples were vented until the hydrogen sulfide disappeared

completely to estimate the content of aromatic sulfur compounds

left over in the product.

4. Results and discussion

4.1. Solubility of hydrogen and syngas in jet fuel

A sufficient amount of hydrogen must be dissolved in the liquid

fuel to convert all the sulfur contained in thefuel to hydrogen sulfide.

The amount of hydrogen that can be dissolved in the fuel is propor-

tional to the overall pressure and can be calculated by Henry's law

(Frolich et al., 1931). Due to the other gases contained in the syngas,

the overall pressure has to be increased in comparison to hydrogen

operation to achieve the same hydrogen partial pressure. The sol-

ubility of the syngas components in jet fuel was calculated on the

basis of literature data (Frolich et al., 1931; Rachner, 1998; Ronze

et al., 2002;Tremper and Prausnitz, 1976). The calculated amount


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Fig. 3. (a) Equilibrium solubility of syngas in jet fuel. (b) Maximum sulfur content in jet fuel to be fully converted depending on syngas pressure in the saturator.

of syngas that can be dissolved in jet fuel is plotted in Fig. 3 as a

function of temperature. The comparison with the measured value

at 80 C(Fig. 3a) shows that the calculated solubility can be used as

reliable data for process estimations.

For stoichiometric reasons the conversion of one mole of such

compounds as thiophene, benzothiophene or dibenzothiophene

demands at least two moles of hydrogen. With regard to the suc-

cessful elimination of these sulfurorganic species, the total pressure

of the syngas makes up, for instance, 24bar for the jet fuel with

sulfur of 700ppm and 70 bar for the sulfur content of 3000ppm.

Fig. 3b represents the dependence between the sulfur concentration

and the pressure of syngas and pure hydrogen, which should be

taken into account in order to carry out the process without the hy-

drogen deficit. For two aforementioned fuels of 700 and 3000 ppm,

the consumption of syngas for the reaction can be estimated equal

to 4.8 and 11.0Ndm3/kg fuel, respectively. During autothermal

reforming 1 kg fuel is converted into 10.000N dm3 hydrogen-rich

syngas. That means that the syngas stream required for the hy-drodesulfurization reaction amounts to approx. 0.1% of the complete

syngas volume.

4.2. Comparison of hydrodesulfurization carried out with syngas and

pure hydrogen

Two points related to the use of syngas should be taken into ac-

count: (i) necessity of higher pressure compared to pure hydrogen

(seeFig. 3b); (ii) unpredictable catalyst behavior due to the pres-

ence of such by-products of reforming as carbon dioxide and car-

bon monoxide. As it is well known, carbon oxides can significantly

worsen the activity of hydrogenation catalysts due to irreversible

processes on the active catalyst sites.In the case of the hydrodesulfurization reaction with pure hydro-

gen, the catalyst is also subjected to aging caused for example by the

deposition of carbon in catalyst pores. Therefore, two series of ex-

periments with hydrogen and syngas have been carried out in order

to compare the impact on the long-time reaction performance. In

both experiments, the operating conditions, temperature, feed flow

rate and catalyst volume were identical, except the pressure. In the

syngas experiment, the total pressure is higher so that the concen-

tration of hydrogen dissolved in the reacting mixture is the same as

in the case of pure hydrogen. The results of these experiments are

shown inFig. 4.

For pure hydrogen the average sulfur content in the product is

14.5ppm with a 95% confidence interval of 4.4ppm. In the case

of syngas the product is characterized by the average value of sulfurof 16.8 ppm with a 95% confidence interval of 2.0 ppm.

Fig. 4. Desulfurization of jet fuel with a sulfur content of 2000 with hydrogen and

syngas at T= 390 C, LHSV = 0.7h1 .

Thus, the comparison of two modes indicates that there is no

significant impact of syngas on the hydrodesulfurization reaction.

4.3. Effect of sulfur content in jet fuel

To determine the effect of different fuel qualities on the productquality, four different jet fuels with different sulfur contents were

used for comparison. The experiments were conducted at an overall

pressure of 70bar, which is enough to convert up to 3000ppm of

aromatic sulfur compounds. The experimental results are shown in

Fig. 5.

Considering the 95%-confidence intervals as shown in Fig. 5for

all jet fuel qualities, the product sulfur content is between 10 and

25 ppm. The fact that the product sulfur content decreases for fuels

with higher sulfur contents could be due to the types of sulfur com-

pounds contained in the fuel and the different aromatic contents.

The results show that hydrodesulfurization with pre-saturation has

the potential to fulfill the target of a 10 ppm sulfur level for high sul-

fur contents of up to 3000 ppm. Further improvements are necessary

to reach a sulfur content below 10 ppm finally. Only one desulfur-ization step is needed to achieve this target.


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292 J. Latz et al. / Chemical Engineering Science 64 (2008) 288-- 293

4.4. Effect of reaction temperature and pressure on product sulfur

content

For process optimization, a two-level factorial plan (Montgomery,

2005)was carried out to investigate the effect of the reaction tem-

perature and the operating pressure on the product sulfur content.

InFig. 6(a) the factorial plan is shown. The temperature and pres-

sure levels were selected on the basis of literature data ( Schmitz,2003;Wache et al., 2006;Montgomery, 2005). To prove that catalyst

degradation has no effect on the results, additionally the first exper-

iment was repeated after all the experiments had been finished, and

no significant difference in product sulfur content was observed.

The experiments were conducted with Jet Fuel HS with 1675ppm

ofsulfur ata LHSVof 0.7 h1. The results show that the reaction tem-

perature is the dominant effect. The product sulfur content decreases

significantly with increasing temperature, while it is influenced only

marginally by the operating pressure (seeFig. 6(b)). Based on the ex-

periment at 31 bar and 330 C, the main effects and the interaction

were calculated as shown byLatz (2008).

All three effects are significant with respect to the95%-confidence

interval (seeTable 3). With these results, the regression for calculat-

ing the product sulfur content cS,Productin the investigated area can

Fig. 5. Dependence of feed sulfur content on product sulfur content at TR=390 C;

pR= 70bar, LHSV = 0.7h1 .

Fig. 6. (a) Experimental plan to determine the effect of reaction temperature and operating pressure on the product sulfur content; (b) product sulfur content dependingon reaction temperature and operating pressure at LHSV = 0.7h1 .

be estimated:

cS,Product= 90 2.533(TR 361) + 0.55(pR 51)

0.0117(TR 361)(pR 51)

The maximum reaction temperature consequently has to be cho-

sen for a minimum product sulfur content. As the typical critical

temperature of jet fuel is 411 C(Rachner, 1998), the maximum tem-

perature is limited. Further experiments showed that at 405 C andan operating pressure of 30 bar the product sulfur content increased

from 30 to 80 ppm within 230 h because of catalyst coking. Thus, it

can be concluded that 390 C is the optimum temperature for tech-

nical applications. To optimize the operating pressure it can be re-

duced until it is not lower than the vapor pressure to assure liquid

phase reaction and until enough hydrogen for the reaction is dis-

solved in the fuel.

4.5. Effect of space velocity on product sulfur content

The effect of space velocity was investigated with Jet Fuel HS. The

experimental results are shown inFig. 7.

Fig. 7 represents the sulfur content in the product with the

estimated 95% confidence interval for three space velocities. Al-

though there is a slight decrease in the sulfur concentration at

LHSV= 0.676 h1, it is quite expected that sulfur content rises at

the growing flow rate of feed.

4.6. Pilot plant testing

To prove the technical concept for H2S separation, to upscale

data and to prove that the process is technically feasible, further

experiments were conducted with a pilot plant for a fuel cell system

with an electric power of 5 kW. The pilot plant was operated for an

experimental time of nearly 200h with Jet A-1 containing 712ppm of

sulfur. In contrast to the roughly 1 l of fuel that was desulfurized in a

single lab-scale experiment, 382l of jet fuel were desulfurized in the

pilot-plant experiment. An amount of 50150 Ndm3/kgFuelnitrogen

Table 3

Main effects and interactions of temperature and pressure of the reaction on the

product sulfur content at LHSV = 0.7h1 .

Effect S-content/ppm

Main effect TR 152

Main effect pR 22

Interaction 14


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Fig. 7. Effect of space velocity at TR= 390 C and p R= 30bar with Jet Fuel HS.

Fig. 8. Feed and product sulfur content after separation of hydrogen sulfide.

was flushed through the product fuel to separate the hydrogen sul-

fide. The results of the pilot-plant experiment are shown in Fig. 8.

The average product sulfur content during the 200-h experiment

was 8.3 ppm with a 95% confidence interval of 0.8 ppm. The max-

imum sulfur level was 10.3ppm.

5. Conclusions

The investigation showed that hydrodesulfurization with pre-

saturation is a feasible process for the desulfurization of jet fuel

in mobile fuel cell applications. While earlier investigations on hy-

drodesulfurization with pre-saturation dealt with pure hydrogen op-

eration, the current studies showed that syngas operation is not a

problem.

Experiments for process optimization resulted in an optimum

reaction temperature of 390 C,andan LHSVof 0.7h1. Theoptimum

operating pressure depends on the sulfur content and the vapor

pressure of the fuel. It is 30bar for a jet fuel with up to 985ppm of

sulfur and 70 bar for a jet fuel with 3000 ppm of sulfur.

Finally, the technical applicability of hydrodesulfurization with

pre-saturation was demonstrated in a pilot plant for a fuel cell APU

with a power of 5 kWe, going beyond the laboratory scale. For thatpower class a hydrodesulfurization reactor running with an LHSV

of 0.7h1 will have a volume of 2.4l. The volume of a complete

hydrodesulfurization system including the reactor and all balance of

plant components will amount to 13.2 l. Further calculations showed

that the integration of a hydrodesulfurization unit with pre-saturator

into a fuel cell system reduces the overall system efficiency by 1%

point.The aimof developing a suitable process forthe desulfurization

of jet fuel in fuel cell APUs has thus been achieved.

Acknowledgments

Part of the work was funded by the Ministry of Economy and

Technology within the National Aerospace Research Programme

(ELBASYS project). The authors thank Mr. R. Dahl, Mr. B. Sobotta,Mr. Y. Wang (Forschungszentrum Julich), Mr. Gerchau, Mrs. Brun-

ner (University of Bayreuth), Mr. Grosch and Mr. Wolfrum (MPCP

GmbH) for valuable technical assistance.

References

Berlin, N.H., McCall, P.P., 1963. Improvements in the Hydrofining of HydrocarbonLiquids, Patent: GB 934907.

Daggett, D., Freeh, J., Balan, C., Birmingham, D., 2003. Fuel Cell APU for CommercialAircraft. In: Proceedings Fuel Cell Seminar, Miami Beach, USA.

Datsevich, L.B., Muhkortov, D.A., 1997. Process for hydrogenation of organiccompounds, Patent: RU 2083540.

Ersoz, A., Olgun, H., Ozdogan, S., 2006. Reforming options for hydrogen productionfrom fossil fuels for PEM fuel cells. Journal of Power Sources 154, 6773.

Frolich, P.K., Tauch, E.J., Hogan, J.J., Peer, A.A., 1931. Solubilities of gases in liquidsat high pressure. Industrial and Engineering Chemistry 23, 548550.

Gislason, J., 2001. Refiners' sulfur dilemmaPhillips sulfur-removal process nearscommercialization. Oil & Gas Journal.

Johnson, M.M., Sughrue, E.L., Owen, S.A., 2003. Desulfurization of Middle Destillates,Patent: WO 03/054117 A1.

Latz, J., 2008. Entschwefelung von Mitteldestillaten fur die Anwendung inmobilen Brenstoffzellen-Systemen. Ph.D. Thesis, Forschungszentrum Julich,

Julich, Germany.Montgomery, D.C., 2005. Design and Analysis of Experiments. Wiley, Hoboken.Peters, R., Latz, J., Pasel, J., Stolten, D., 2008. Desulfurization of Jet A-1 and heating

oil: general aspects and experimental results. ECS Transactions 12 (1), 543554.Rachner, M., 1998. Die Stoffeigenschaften von Kerosin Jet A-1, DLR-Mitteilung 98-01,

Cologne, Germany.Ronze, D., Fongarland, P., Pitault, I., Forissier, M., 2002. Hydrogen solubility in straight

run gasoil. Chemical Engineering Science 57, 547553.Schmitz, C., 2003. Zur Kinetik und zur verbesserten Reaktionsfuhrung der

hydrierenden Tiefentschwefelung von Dieselol. Ph.D. Thesis, University ofBayreuth, Bayreuth, Germany.

Schmitz, C., Datsevich, L., Jess, A., 2004. Deep desulfurization of diesel oil: kineticstudies and process-improvement by the use of a two-phase reactor with pre-

saturator. Chemical Engineering Science 59, 28212829.Specchia, S., Cutillo, A., Saracco, G., Specchia, V., 2006. Concept study on ATR and SR

fuel processors for liquid hydrocarbons. Industrial and Engineering ChemistryResearch 45, 52985307.

Tremper, K.K., Prausnitz, J.M., 1976. Solubility of inorganic gases in high-boilinghydrocarbon solvents. Journal of Chemical & Engineering Data 21 (3), 295299.

Wache, W., Datsevich, L., Jess, A., Neumann, G., 2006. Improved deep desulphurisationof middle distillates by a two-phase reactor with pre-saturator. Fuel 85,14831493.

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Methane hydrogenolysis