Linde pilot testing dry reforming process to generate syngas from CO2 and methane for production of fuels and chemicals
16 October 2015
As part of its R&D strategy, Linde has built a pilot reformer facility at Pullach near Munich—Linde’s largest location worldwide—to test dry-reforming technology. The dry reforming process catalytically combines CH4, the principal component of natural gas, and CO2 to produce syngas (CO and H2). Syngas is then used to produce valuable downstream products such as base chemicals or fuels.
The dry reforming process differs from steam reforming, which combines CH4 and water (H2O) in the form of steam to produce the syngas. Producing the steam is energy-intensive; dry reforming requires far less water, and hence avoids the energy burden of steam production. In addition to reducing energy consumption, the dry reforming process also consumes recycled carbon dioxide.
The dry reforming process also offers cost efficiencies relative to partial oxidation—these would be of particular interest to small and medium-sized plants.
Among the other benefits of the dry reforming approach is syngas with an H2/CO ratio of about 1, while steam reforming delivers an H2/CO of about 3 and partial oxidation a ratio of about 2. For some applications such as Fischer-Tropsch fuel synthesis, the low H2/CO ratio is desirable.
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| Linde Pilot Reformer. Click to enlarge. |
Although processes and catalysts for dry reforming of methane at low pressure levels are well known and established, these processes require that the generated CO-rich syngas is compressed to the pressure level of the corresponding downstream processes. Post-compression of syngas with high CO contents is technically not an easy task, notes Linde development partner Karlsruhe Institute of Technology (KIT).
To address that particular issue, KIT has focused on developing and designing new catalyst and process options for dry reforming at elevated pressure.
Engineers from Linde and development partner BASF further discussed the technical and economic challenges of dry reforming in a paper published earlier this year in the journal Chemie Ingenieur Technik (Schwab et al.).
Linde intends to use this pilot facility to test and optimize all kinds of approaches to reforming. The insights we gain will help us further improve reforming processes and concepts for our customers.
—Dr. Christian Bruch, Member of the Executive Board of Linde AG
Tests in the pilot reformer are currently focused on dry reforming. This innovative process was developed by Linde in cooperation with its partners BASF (responsible for catalyst development); Karlsruhe Institute of Technology / KIT (responsible for simulations); and DECHEMA (supplier of materials). The pilot project has been awarded funding by the German Ministry for Economic Affairs and Energy (BMWi) of just under one €1 million.
If the dry reforming pilot proves successful, there are plans to commercialize the process when the funded project comes to an end in 2017 and to build a reference plant for a Linde customer.
Resources
Schwab, E., Milanov, A., Schunk, S. A., Behrens, A. and Schödel, N. (2015), “Dry Reforming and Reverse Water Gas Shift: Alternatives for Syngas Production?” Chemie Ingenieur Technik, 87: 347–353. doi: 10.1002/cite.201400111
Hanaâ Er-rbib, Chakib Bouallou, François Werkoff (2012) “Production of synthetic gasoline and diesel fuel from dry reforming of methane” Energia Procedia doi: 10.1016/j.egypro.2012.09.020
This made me raise an eyebrow:
A syngas with a 1:1 CO:H2 ratio has an average molecular weight of 15, and as both are diatomic gases the Cp/Cv should be about 1.4. The former is very close to methane, the latter the same as air. What's so difficult about this?
Posted by: Engineer-Poet | 16 October 2015 at 09:01 AM
I was hoping to look at the linked notes and appear clever about the compression, but they give no more details there, so that is me stuffed! :-(
Posted by: Davemart | 17 October 2015 at 05:19 AM
After the syngas it's Fischer Tropsch time.
Posted by: Mannstein | 18 October 2015 at 09:03 AM
Either FT or MTG. The Mobil process scales down well, producing methanol, DME, gasoline, kerosene or diesel.
Posted by: SJC | 18 October 2015 at 08:36 PM
Biogas would be an excellent feed to this process since it contains 35% CO2. Oberon Fuels has scaled down DME and Methanol production using Biogas. Ford is investigating the use of DME and Oxymethylene Ether (OME) as a fuel for Compression Ignition engines. Looks like a good process for 2nd gen biofuels.
Posted by: Account Deleted | 19 October 2015 at 07:59 AM
The problem of post-catalytic compression is spelled out in the link. Coke formation is thermodynamically favored, while more-than-isothermic compression will sinter the catalyst.
CO is not a terribly stable compound and could disproportionate into CO2, which is the favored stable state. Since methane has twice the hydrogen per mole as H2, you might also be looking at a reverse reaction under higher compression -- entirely possible on the same catalyst (no wonder enzymes are designed in nature to be so reaction-directionally specific). So you have to be careful of back pressure effects. When you are dealing with three or more chemical species in the same pot (H2, CH4, CO2, likely some oxygen to initiate combustion, etc.) your reaction kinetics can be very difficult to figure out.
Posted by: kalendjay | 19 October 2015 at 04:07 PM
Ah, they must be talking about compressing hot gas. I was assuming room temperature.
Posted by: Engineer-Poet | 20 October 2015 at 04:00 PM