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On-site Hydrogen Generators from Hydrocarbons

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Contents

Introduction

The aim of the WP1 task 1.3 is to assess the various pathways to bring hydrogen fuel to the consumer. Among all these various pathways, the on-site hydrogen production from fossil fuels is the most attractive one (refer figure below).

On site reforming of hydrocarbon is the 2nd cheapest pathway option to bring to the consumer in hydrogen in hydrogen station[1]

The objective of this report is to evaluate more precisely the various technologies and associated economics of on-site hydrogen production.

This transition pathway gives rise to CO2 emissions but the advantages due to the price and commercial status of the technology are such compared with the CO2 free technologies that this pathway will play a major role in the initial development of the hydrogen filling stations. The main candidate hydrocarbons are natural gas and LPGs and possibly at a later stage, GTL diesel and biogas.

State of the Art

Technology Status of Small Scale Hydrogen Production from Hydrocarbons

Steam reforming is essentially the only technology used commercially for the small scale production of hydrogen from hydrocarbons. Custom made small scale reformers have been offered since the 1950's by a small number of dedicated vendors and by larger engineering companies on a special order basis. The number of small scale reformers in the world, between 50 and 5000 Nm3/h, can be estimated to be around 1500[2]. In the 50 to 600 Nm3/h range, they compete in the industrial gas market with hydrogen deliveries and electrolyzers.

Due to their relatively high prices the small on-site generators occupy only a small fraction of that market. They usually operate on natural gas, LPGs and methanol, which are the feed-stocks for which there is a widespread distribution infrastructure.

Large scale reformers also operate on naphtha in petrochemical plants. Heavier feeds are not suitable for steam reforming because of their higher sulfur content and propensity to cause carbon fouling of the catalysts.

Most of the small scale reformers currently offered are derived from the well established large scale steam reforming processes. However, spurred by the perspectives generated by the development of the hydrogen economy and fuel cells, a number of new players have begun to enter the market with less expensive and innovative units developed often as scale-up versions of fuel processors for fuel cells. This trend is continuing today and new technologies have emerged and continue to develop. HyRadix, USA, is one of the newcomers that offers a product with a technology not based on steam reforming but on catalytic autothermal reforming. This report aims at presenting a snapshot of the current situation of small scale reforming in terms of technology, markets and players.

Commercial Technologies for Hydrogen Production from Hydrocarbons

As mentioned above, nearly all small scale reformers available today are down-scaled versions of the large scale steam reforming technology. Only Hyradix USA offers catalytic auto-thermal reforming, which is a novel technology as an alternative to steam reforming. Steam reforming is more amenable to down-scaling than the other two major large scale technologies for converting hydrocarbons into hydrogen which are partial oxidation, and autothermal reforming. Partial oxidation which is a non catalytic thermal process, leads to a syngas with a lower H/C ratio and produces some soot which would be very difficult to handle at the lower scale. Autothermal reforming combines a partial oxidation step and a steam reforming step.

Excellent reviews of the established industrial processes for the production of hydrogen from hydrocarbon are regularly published[3]. We present here a very brief reminder in order to highlight better the specificities of the small scale reformers. We consider here only the industrial processes that are used to produce hydrogen specifically and do not discuss the processes that produce hydrogen as a by-product, such as some petroleum refining processes and the acetylene plasma process, e.g. These processes account for at least one third of the hydrogen produced in the world but most of that hydrogen is used "in-house" where it is produced, without entering the hydrogen market. Besides, none of these processes that yield by-product hydrogen is considered for the small scale production of hydrogen.

  • Basic chemical reactions

There are three basic set of reactions/operations that permit hydrogen to be obtained from hydrocarbons.

1. Steam reforming + shift + H2/CO2 separation

CnHm + n H2O → n CO + (n + m/2) H2 + ∆H (endothermic)

CO + H2O → CO2 + H2

H2 + CO2 → H2 (separation)

2. Partial oxidation (thermal) + shift + H2/CO2 separation

CnHm + n/2 O2 → n CO + m/2 H2 - ∆H (exothermic)

CO + H2O → CO2 + H2

H2 + CO2 → H2 (separation)

3. Decomposition

CnHm → n C + m/2 H2 - ∆H (exothermic)

n C + m/2 H2 → H2 (separation)

In the late fifties, Haldor Topsoe introduced the autothermal reforming which uses partial oxidation as a first step to provide the heat for the endothermic steam reforming.

  • Large scale processes

1. Steam reforming

Most of "on purpose" hydrogen (over 90%) is manufactured today via the steam reforming of natural gas[4]. Industrial experience (since 1930) shows that this technology is reliable and mature. The global conversion occurs in three steps:

Steam methane reforming -SMR- is the endothermic conversion of methane and water vapour into hydrogen and carbon monoxide. The required heat for the reaction is provided by natural gas combustion eventually supplemented by combustion of the purge gas from the hydrogen purification step. The process typically is carried out at temperatures of 700 to 900°C and pressures of 10 to 40 bars in order to maximize output despite the thermodynamically adverse effect of increasing the pressure.


SMR reactor furnace designs[5]

The reaction takes place in presence of a nickel catalyst, supported on low surface area alumina or ceramic aluminates (12-25 wt% Ni). This catalyst is very sensitive to sulphur. Sulphur is removed, usually by HDS, ahead of the reforming reactor. Excess steam is required to avoid coking of the reforming catalyst and reactor tubes, typically a steam-to-carbon mass ratio of 3. Reactor furnaces may contains several hundred tubes up to 15 m high and 10 cm ID, which makes steam reforming a very capital intensive process. Four main furnace designs exist: top, side, radiant and terrace fired (figure).

In the second step, CO produced in the first step is converted to CO2 with the concomitant production of hydrogen by the mildly exothermic water gas shift reaction Two successive beds of shift catalysts are used: a high temperature shift with a HTS catalyst at 400°C, 89 wt% Fe2O3 + 9 wt% Cr2O3, unsupported, and a LTS catalyst at 250°C, typically 35 wt% CuO + 65 wt% ZnO + promoters. This catalyst is prone to poisoning. A recent trend is to replace the HTS catalyst by a copper containing MTS catalyst.

An initial prereforming step (milder conditions) is sometimes added prior reforming in order to take care of the higher hydrocarbons.

The third and final step consists in the separation of H2 and CO2 by pressure swing adsorption (PSA) technology, which can produce hydrogen in concentrations up to 99.999%. The PSA processes have started replacing the methanation / decarbonatation processes at the end of the seventies.

2. Partial oxidation

For liquid feed-stocks with final boiling points higher than 240°C, the steam reforming process is not adapted because of the propensity of the nickel catalyst to coke. Partial oxidation processes, that are thermal processes which do not use catalysts in the initial syngas production step, can be used then. These processes can also handle solid hydrocarbons such as coke and coal, in which case they are called gasification processes.

Partial oxidation/gasification processes are very flexible in terms of feedstocks, from natural gas to coal, but they are more capital intensive than steam reforming, especially due to the oxygen plant, and they have a lower efficiency for hydrogen production. They yield a syngas with a lower H2/CO ratio which is more adapted to chemical synthesis than the syngas produced by steam reforming (except ammonia). For these reasons, only partial oxidation processes are considered in Gas To Liquids projects, which involve a Fischer-Tropsch[6] conversion. There are about 500 gasification plants in the world today[7]. Most of them produce syngas for clean electricity production.

Whenever light hydrocarbons are available, POX is less attractive than SMR for large volume hydrogen production, as confirmed by the fact that 90% of the "on purpose" hydrogen production is by SMR.

However, a number of potential advantages of POX over SMR have been perceived by the suppliers of small scale hydrogen production units: lower capital cost and faster response time to hydrogen demand. The arguments will be detailed in section 3 as well as the outcome of the attempts to develop small scale hydrogen production units based on partial oxidation.


POX and ATR reactor.
Source : ConocoPhillips

3. Autothermal reforming

Autothermal reforming is a combination of partial oxidation and steam reforming where the necessary reforming heat demand is supplied by the partial oxidation. Steam is added to the feed streams to prevent carbon formation, and allow safe premixing of methane. The furnace system is simple and more compact than a steam reformer and it is therefore less costly. The upper part of the reactor is similar to a partial oxidation reactor (figure). It is followed by a catalytic steam reforming section. Shift and PSA are the next step of the process.


4. Decomposition

In principle, hydrogen could be obtained from methane by simple decomposition. However, the reaction is very endothermic with a high activation energy barrier to overcome. In the fifties UOP (Honeywell Company) built a natural gas pyrolysis pilot plant but the process never became commercial. Today, to our knowledge, there is only one plant in the world that practices the natural gas decomposition. It is operated by Cancarb in Alberta for carbon black production.

The hydrogen co-produced is used as heating fuel for the process. Pyrolysis at very short contact times (~15 ms) kinetically yields a high fraction of acetylene in place of 100% carbon black.

This is the principle of the plasma acetylene process that supplies large quantities of hydrogen in the hydrogen pipeline network in the Ruhr area. The methane decomposition pathway has been touted as a route to obtain hydrogen without the concomitant production of CO2 but the high energy requirements limit the interest of the process to situations where large quantities of clean free energy are available, namely solar energy (see the "Emerging Technologies" section).

Small Scale Commercial Technologies and Vendors

  • New market prospects and incentives for innovation

Custom made small scale reformers have been offered since the 1950's by a small number of dedicated vendors and by larger engineering companies on a special order basis. Between 50 to 600 Nm3/h range, they compete in the industrial gas market with hydrogen deliveries and electrolyzers. Due to their relatively high prices they occupy only a very small fraction of that market.

They usually operate on methanol, LPGs and natural gas, and, which are the feedstocks for which there is a widespread distribution infrastructure. Their market share situation has been stable, if not dormant, for years but the prospects introduced by the forthcoming hydrogen "economy" and fuel cell markets have motivated many newcomers involved in the design of fuel processors for fuel cells. These new players have tried to compete as well in the industrial gas market and take advantage of the innovations introduced on this occasion. The design of fuel processors introduces indeed many challenges. Table 1 below lists a few of these challenges and corresponding solutions offered by the fuel processor nascent industry.

Table 1: Specific technological challenges encountered in the design of fuel processors and a few typical solutions implemented by the fuel processor industry

Challenge solution
Physical size Miniature heat exchangers
Efficiency (objective > 75%) Pinch analysis, heat exchange reactors
Emissions (NOx, …), anode gas combustion Catalytic burners, -
Response to transient fuel cell demands Micro-channel reactors, -
Quick start-up Catalytic partial oxidation, -
Non pyrophoric catalysts Precious metal catalysts, -
Feedstock sulfur removal Improved adsorbents or HDS at mild conditions
~zero level of CO in the reformate PROX, membranes, -
Handling « tough » feedstocks: diesel, biogas Thermal reforming, -
Cost Standardization and mass production


At this time, the innovations introduced by the fuel cell processor industry have yet to be fully translated into commercial products. However, a few newcomers have begun to offer commercial units that carry a price tag well below those offered by the more established vendors. The new units also offer advantages in terms of footprint, efficiency, appearance and all the other features that are mandatory for the future hydrogen filling stations. However, only time will say whether they will have the reliability that the more traditional units have demonstrated over the years.

Besides, the traditional vendors have reacted to the challenge and are working on improving their product line. All these factors may improve the competitiveness of the small scale reformers. They may therefore capture a larger bite of the hydrogen industrial gas market, before expanding on the hydrogen refuelling station market when hydrogen vehicles will begin to appear, which is still undetermined.

  • Vendors

1. Traditional vendors

Here is a short list of traditional dedicated vendors of small scale reformers. It is understood, as explained earlier, that other companies especially petroleum engineering companies, are able to and have supplied small scale reformers. The list is therefore not exhaustive.

USA : Hydro-Chem/Linde, Pan American Enterprises

Germany : Mahler, Caloric.

Japan : MKK (Mitsubishi Kakoki Kaisha Ltd).

2. A few new players (since 2000)

CarboTech has developed a compact reformer based on WS-Reformer-GmbH reformer technology (Floxâ) and their own PSA technology. CarboTech has delivered one unit to Repsol as a part of the EU-CUTE project for the H2-filling station in Madrid. Moreover, the company has also delivered a 100 Nm3.h-1 unit to Linde AG for the Munich Airport station.

H2Gen is offering a compact reformer (53 Nm3/h) using sulphur resistant catalysts. Hydrogen is produced at a pressure of 15 bar and a purity of 99.999%.The unit has a small size of 2.13 m x 2.90 m x 2.16 m, and a weight of 3175 kg[8]

Harvest has supplied several steam compact regenerative reformers with capacities between 35 and 70 Nm3.h-1.

Hygear (previously Hexion) has developed several steam reformers with PSA purification between 5 and 50 Nm3.h-1.

HyRadix uses catalytic autothermal reforming at high-pressure (7 bar). Ultimate impurities are nitrogen and argon.

Osaka Gas has supplied natural gas reformers for hydrogen filling stations and industrial customers . The efficiency is 70% HHV basis. Osaka Gas uses ruthenium steam reforming catalysts. The shift reactor is integrated with a HDS unit. The product purity is reported to be 99.999. Two HYSERVE-30 units have been in operation at a metal treating plant since January 2002. A durability of 90,000 hours was demonstrated that includes 1200 shut-down/start-up cycles and 25,000 load-change operations.

Plug Power offers GenSite-H2 units with a production capacity of 8 Nm3.h-1 at a pressure of 10 bar. The unit provides hydrogen with a purity of 99.95% and CO-CO2 impurities of 10 ppm.

A few examples, 30-100 Nm3/h, are provided below.


Emerging technologies (non-commercial)

Large Scale

The large scale reforming and partial oxidation technologies are considered as mature technologies for which only slight incremental improvement can be made. It is also recognized that these technologies remain very capital intensive technologies for which alternatives should be found, especially in the context of the transportation of stranded gas (GTL).

For this application, two novel syngas production routes have attracted considerable attention for the past 10 years and have been the object of pilot plant development. They are mentioned here because it was attempted to adapt these technologies to the small scale generation of hydrogen.

  • Short contact time catalytic partial oxidation reactors

The short contact time catalytic partial oxidation, discovered in academia in 1992, raised the interest of several major companies - Shell, Haldor-Topsoe, ENI, ConocoPhillips - who evaluated the reaction at the pilot plant scale.

In 2005, ConocoPhillips demonstrated their COPOX™ technology for producing the synthesis gas required for a 400 BBLD Fischer-Tropsch plant. However, a few of them, such as Shell and Haldor-Topsoe, announced that they had stopped the effort.

Shell and UTC Fuel Cells had created a joint venture -Hydrogen Source- to develop the technology for fuel processors and on-site hydrogen generation. Hydrogen Source was dissolved in 2004.

  • Oxygen Transport Membrane reactors

OTM offer the possibility of generating syngas from natural gas in GTL plants without the requirement of an expensive oxygen plant (up to 40% of the total cost of a GTL plan). The DOE and the US industry have spent several million $ on the scale up of the membranes before redirecting the R&D on smaller systems for on-site hydrogen generation and fuel processors.

  • Plate reformers

Accentus (a subsidiary of AEA technology formerly the UK Atomic Energy Agency) has demonstrated a plate reformer for offshore GTL process[9]. The GTL Microsystems process employ Steam/Methane reforming and a proprietary metal substrate catalyst within the reactor channels. The technology improvement is claim to lead to an excellent heat transfer combined with a novel catalyst configuration and allows operation at a lower steam to methane ratio improving efficiency without catalyst deactivation or coking.

Small Scale

The US DOE and the European Commission support industry for the development of many alternatives to steam reforming for on-site hydrogen generators. A partial list of these emerging technologies is given below with the names of the industrial players involved.

  • Membrane reactors

One of the most original development over recent years is a new concept that integrates oxygen separation, steam reforming and POX into a single step. The Argonne national laboratory, in cooperation with Amoco, has pioneered in 1997 the use of membrane technology that selectively extracts pure oxygen from air. By providing oxygen at low cost, the membrane process could lower the cost of H2 production.

Praxair ITM concept combining oxygen (OTM) and hydrogen (HTM) ion transporting membranes

Praxair (in collaboration with BP, Statoil, Sasol) is developing a small scale system that combines an ATR based oxygen membrane with a water-gas shift reactor incorporating a hydrogen membrane. Praxair is developing a Pd-Ag hydrogen membrane supported on a ceramic material (Figure). Control of the pore size and porosity of the ceramic substrate is critical to ensuring that the Pd-Ag coating is leak-free. To reach significant hydrogen fluxes porous ceramic substrate and thin film membranes are needed. Hydrogen flux also increases with increased partial pressure and operating temperature. Several designs were tested with substrate pore sizes between 50 and 5 mm, and membrane film thicknesses of 15-8 microns.

Membrane Reactor Technology (MRT) has started the development of a fluidized-bed ATR reactor with in-situ separation of hydrogen by a planar Pd-membrane. A 50 Nm3.h-1 (2 m x 4.6 m x 2.1 m) prototype has been built that produces hydrogen at 7 bar with a purity of 99.99%. The unit converts grid NG (20 Nm3/h) with an efficiency of 82% (HHV).

Mitsubishi Heavy Industries has developed a steam reformer of natural gas equipped with palladium membranes for hydrogen separation (refer Figure below). The natural gas, mixed with steam and preheated by the exhaust gas from the burner, is converted to mainly hydrogen and CO2 in the catalyst bed. The hydrogen is separated inside the membrane and withdrawn from the reformer at atmospheric pressure.

Mitsubishi Heavy Industries membrane reformer[10]
  • Plate-type, microchannel and heat exchanger reformers

Plate-type reformers are smaller and lighter than steam reformers. This design of reformer uses several plates. For each plate, one side is coated with steam reforming catalysts and is supplied with methane and steam, and on the other side of the plate, the methane undergoes catalytic combustion, providing the necessary heat for the endothermic steam reforming.

They have demonstrated heat transfer rates higher than 20-200 kW.m-2 in laboratory tests and up to 50 kW.cm-3 reactor volume.

a)Drawing of a plate reformer b)Principle of operation of the Advantica reformer[11]

The residence time is in order of milliseconds compared to about 1 second for conventional reformers.

Advantages of the plate design are compactness, standardized design (lower cost), better heat transfer (and therefore better conversion efficiency), fast start-up (lower thermal inertia than packed catalyst bed), and easier integration with PEM fuel cells when running at 600°C (figure a and b).

The plate reformers were developed for the integration with fuel cells. The following companies are actively working in this area:


Section of heat exchanger reformer. Modine/Chevron technology

Ztek is using a special type of plate reformer where the plates are used as heat transfer medium. They have built an 18 Nm-3.h-1 prototype that produces hydrogen with a purity of 99.99%, and operated it for 8000 hrs[12]

Velocys has developed a micro-channel reformer concept that has been applied for syngas production. This concept can also with small modifications be used for small-scale hydrogen production.

ChevronTexaco with Modine, a heat exchanger company, has developed an ATR based hydrogen process that was put in operation in February 2005 at the Hyundai-Kia American Center, in Chino, California. The unit produces hydrogen from natural gas, using ChevronTexaco Technology Ventures proprietary autothermal reforming technology with close loop integration of steam reforming and catalytic combustion over a heat exchanger specifically designed (figure). The unit is claimed to be capable of producing hydrogen from corn-based ethanol.

  • Methane decomposition

1. Catalytic decomposition of methane

The catalytic decomposition of methane is an environmentally attractive approach to CO2-free hydrogen production[13]. In this process, methane is broken down to hydrogen and carbon, sometimes in the presence of a catalyst at 800-1200oC, according to the reaction:

CH4 → C(s) + 2 H2

The reaction is endothermic (75,6 kJ.mol-1) and requires an energy input. Various transition metal catalysts have been used to reduce the temperature of the decomposition. Frequent regeneration of the catalyst is required to removed accumulated carbon, but relatively low capital costs are projected because of the system simplicity.

2. Plasma reformers

The plasma technology is already used for wastes destruction and acetylene synthesis and can be applied for producing hydrogen from hydrocarbons fuels. Plasma processes have the advantages of rapid startup, small reactor size and short response times to demand compared with catalytic systems characterized by higher inertia. These advantages would be particularly attractive for fuel processors and have motivated a lot of R&D activities. They also well adapted to handle a large variety of feed-stocks (natural gas, gasoline, alcohols, diesel and biomass).

Currently, several plasma concepts are under development for small-scale hydrogen production.

MIT (worked with BP Amoco, Texaco[14]) has tested several designs including partial oxidation of diesel[15] (figure 7). A stream of 40% hydrogen can be obtained after the shift reaction. Power conversion efficiencies of 70-80% and start-up times of 90 seconds are claimed. Disadvantages of plasma reforming include the degradation of the anode that needs to be replaced every 1000 hours[16] and electrical power consumption.

  • Reformers with cyclic regeneration of solid materials

Sorbent-enhanced reforming

The aim of sorbent-enhanced reforming is to help the kinetics and thermodynamics and simplify the reforming process by the continuous removal of the carbon dioxide from the reaction zone[17]. In one step, it is possible to obtain a stream of 95% pure hydrogen without the recourse to a shift reaction. This can either be done by using an internal adsorbent such as calcium oxide. Because absorption is exothermic and steam reforming is endothermic, the energy requirement is significantly reduced by combining these reactions. The adsorbent has to be regenerated once fully converted into a carbonate.

Potential advantages of this concept are simpler design (no shift reactor and less constraint on or no PSA), low reaction temperatures (below 500°C), reduced clean-up cost, and CO2 capture. Sorbent materials should satisfy the following conditions: high CO2 uptake, rapid kinetics, stability at high steam concentration, regenerable and low cost.

Autothermal Cyclic Reforming (ACR) from General Electric

ECN[18], ChevronTexaco with Cabot[19], IFE Norway and ZSW Germany are working on the development of new sorbent materials.

  • Autothermal Cyclic Reformer (ACR)

General Electric Global Research is developing an Autothermal Cyclic Reformer (ACR) for hydrogen filling stations. ACR uses steam reforming operating in a 3-steps cycle: (step 1 - Reforming) steam reforming of the fuel in a Ni catalyst bed, (step 2 - Air Regeneration) heating the catalyst bed through oxidation of the Ni catalyst, and (step 3 - Fuel Regeneration) reducing the catalyst to the metallic state.

The heat required for the endothermic reforming step is provided during the exothermic air regeneration step.

The ACR process consists of two reactors cycling between the reforming and regeneration (air and fuel) steps (figure). The product stream is 70% hydrogen rich. CO concentrations at inlet and outlet of the shift reactor are 13-20% and 1.25% respectively. Praxair has developed a 3-bed PSA for integration with the ACR reactor. Preliminary tests show a hydrogen purity of 99.996% and 75% recovery at 120 psig[20]

Main Metrics

METRIC SUB-METRIC DATA / RATING UNITS Onsite Reformer
Natural Gas LPG Bio-ethanol Gasoline Methanol
SMR POX ATR CPO
Technology Accessibility Compatibility with existing technologies Rating 0-4 4 1 3 1 3 1 1 2
Number of producers Data number 15 4 4 1 5 4 4 4
Possibility of extending existing raffineries Rating 0-4 N/A N/A N/A N/A N/A N/A N/A N/A
Global Environmental Impact GHG emissions associated with fuel production Data gCO2 eq / kg fuel 12000 12000 12000 12000 19300 N/A 21600 12200
CO2 emissions associated with fuel production Data gCO2 / kg fuel 10600 10600 10600 10600 17000 N/A 19100 10800
Efficiency Part load energy efficiency of technology Data %                
Full load energy efficiency of technology Data % 71-76 66-76 66-73 >75 80 84 80 75/80
Energy efficiency of auxiliary facilities Data % N/A N/A N/A N/A N/A N/A N/A N/A
Capacity & Availability Measured fuel production / supply Data kg fuel / year N/A N/A N/A N/A N/A N/A N/A N/A
Maximum fuel production / supply (capacity) Data kg fuel / year N/A N/A N/A N/A N/A N/A N/A N/A
Number of hours per year energy is available (regular use - maintenance hours, expected repairs or failures) Data hours / year N/A N/A N/A N/A N/A N/A N/A N/A
Cost
(click here for more datails) 		Capital investment for fuel production facilities Data €/capacity 905 €/kW (1502 US$/kg/d)[21]
Operational / maintenance cost (labour, electric energy cost etc.) Data €/year 211904 €/yr (213871 US$/yr, 470 kg/d)[22]
Decommisioning cost Data €/capacity N/A
Selling price of fuel produced Data €/kg 4.78 €/kg[23]


N/A: Not Available

Market/Diffusion

The hydrogen industrial gas market

As mentioned earlier, it is presently the main market for small-scale reformers. The figure below indicates what the potential markets are for the on-site hydrogen generators, between 30 and 800 Nm3/h, on the condition that their prices drop by a factor of about 4 compared with the prices of the traditional vendors listed in before. Today this target appears realistic in view of the latest prices offered by some by a few of the vendors of on-site fuel reformers.

Now the on-site hydrogen production with reformers is on the verge to be able to compete with the hydrogen deliveries by truck.


Hydrogen market. Air Liquide prospects

The hydrogen filling market

There are 135,000 service stations in EU-25 in Europe. The wish of the European Commission for the market share of hydrogen in the transportation sector is 5 % by 2020 This corresponds to about 8000 filling stations with a capacity of 1000 Nm3 H2/h[24].About 200 hydrogen-filling stations have been built for demonstration purposes so far[25] more than one third of them based on reforming (figure).

Evolution of the number of refueling stations and H2 origin
Source : Gaz de France, 2005

In the medium term (2030), a significant fraction of hydrogen is expected to be produced by on-site reforming of natural gas and other hydrocarbons. The initial size of small-scale reformers for hydrogen filling stations should be between100 and 300 Nm3 H2/hr. This size is considered suitable for the early stages of the hydrogen economy (i.e. 2015), in line with the anticipated numbers of the first hydrogen vehicles. In a few areas where trucked-in hydrogen is expensive, on-site reforming is an attractive alternative right now. In the long-term it is expected that large-scale hydrogen production with CO2 capture and pipeline distribution will be the option of choice in densely populated areas.

The CHP market

The Strategic Research Agenda of the Hydrogen & Fuel Cell Platform of the European Commission foresees that by 2030, 25% of presently centralized power generation in Europe will be replaced by distributed energy systems, operating essentially on natural gas. The Deployment Strategy snapshot assumed that by 2020 the cumulated number of units, including fuel cells, sold could be between 400 000 and 800 000 representing 8 and 16 GWe of installed capacity. Although probably optimistic, these numbers are an indication that the size of the fuel processor market will be significant if stationary fuel cells develop as predicted.

These units may or may not include a fuel processor depending whether they are PEMFCs or SOFCs. Fuel processors produce a reformate which is a mixture of H2, CO2 and eventually N2. They are integrated in fuel cells and cannot be considered small scale hydrogen generators. Small scale hydrogen generators for the CHP market will develop only for feeding local hydrogen grids if these grids are ever constructed.

Notes

  1. ↑ D.R. Simbeck & E. Chang SFA Pacific, hydrogen supply cost estimate for H2 pathways: scoping analysis NREL report, July 2002, NREL/SR-540-32525.
  2. ↑ Estimate based on the data published by Hydrochem/Linde, a vendor of small scale hydrogen plants.
  3. ↑ R. J. Farrauto and C. H. Bartholomew, Fundamentals of industrial catalytic processors, 1997, Chapman and Hall.
  4. ↑ G.H. Shahani et al. Hydrogen and Utility Supply Optimization. Hydrocarbon Processing, page 143, September 1998.
  5. ↑ Rostrup-Nielsen: Catalytic Steam Reforming, Springer, Berlin 1984)
  6. ↑ “Natural Gas To Liquids (Fischer-Tropsch)” , Pétrole et techniques n°415, July/August 1998.
  7. ↑ J. Saint-Just, La production de gaz manufacturés, Gaz d’aujourd’hui, Septembre 2000, 10,50-54, 2000.
  8. ↑ [1]
  9. ↑ [2]
  10. ↑ [3]
  11. ↑ D.R. Simbeck & E. Chang SFA Pacific, hydrogen supply cost estimate for H2 pathways: scoping analysis NREL report, July 2002, NREL/SR-540-32525.
  12. ↑ [4]
  13. ↑ Muradov N., Catalysis today, 116, 281-288 (2006).
  14. ↑ [5]
  15. ↑ [6]
  16. ↑ L Bromberg, DR Cohn, A Rabinovich, N Alexeev, Plasma Catalytic Reforming of Methane, IJHE, 24(1999) 1131-37
  17. ↑ Hildenbrand N., Applied Catalysis A, general 303, 131-137 (2006).
  18. ↑ H. T. J Reijers, D. F. Roskam-Bakker, J. W. Dijkstra, R. P. de Shmidt, A. de Groot, R. W. van den Brink, Hydrogen production, through sorption enhanced reforming,ECN, the Netherlands [7]
  19. ↑ J Stevens, Development of a 50-kW Fuel Processor for Stationary Fuel Cell Applications Using Revolutionary Materials for Absorption-Enhanced Natural Gas Reforming, DOE hydrogen program, FY 2003, [8]
  20. ↑ R. Kumar et al., Autothermal cyclic reforming based hydrogen generating and dispensing systems, DOE hydrogen program, FY 2004, [9]
  21. ↑ D. Simbeck, E. Chang, Hydrogen Supply: Cost Estimate for Hydrogen Pathways - Scoping Analysis NREL/SR-540-32525, November 2002
  22. ↑ Cite error: Invalid <ref> tag; no text was provided for refs named h2supply
  23. ↑ Affordable hydrogen transportation system, WHEC 16, Lyon, France, June 2006
  24. ↑ IEA, Hydrogen Implementing Agreement Task 16 Subtask C Final Report.
  25. ↑ [10]
Hydrogen Production

Hydrogen Production from Fossile Sources | Hydrogen Production from Biomass | HT Reactor Associated to Thermo-chemical Cycles | On-site Electrolysis | On-site Hydrogen Generators from Hydrocarbons

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