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London Could Generate 141 Tonnes of H2 Daily from Waste by 2020

9 October 2006

The London Hydrogen Partnership has released a report that concludes it is theoretically possible for the city of London to generate 141 tonnes of hydrogen per day from waste, using both gasification/pyrolysis and anaerobic digestion of all municipal and commercial waste. Of that 141 tonnes, 68 tonnes could come from just municipal waste—conceivably under the control of a single waste authority.

The daily 141 tonnes could potentially fuel a fleet of 13,750 fuel-cell hybrid and hydrogen hybrid internal combustion engine buses. The current London fleet has slightly more than 8,000 buses. The report notes, however, that since much of the hydrogen would be used for power generation, the 13,750 figure represents the potential, not the expected production.

Gasification would produce a synthesis gas (syngas)—a mixture of hydrogen, carbon monoxide and carbon dioxide, plus small amounts of methane. For hydrogen production, the syngas would be cleaned, reformed and then go through the water-gas shift process to convert carbon monoxide to hydrogen. Further purification would be required for the hydrogen to be of the necessary quality for use in a fuel cell.

...the volume of gas produced is only 20-25% of that produced by incineration, therefore substantially lowering the capital cost of the clean-up equipment. Emissions of local pollutants are substantially lower than incineration, although their exact levels depend on the technology deployed and would have to be monitored in the same way as the emissions from incinerators. Gasifiers are also more modular than incinerators, allowing more flexibility in their use for waste management; the size envisaged in London would treat around 90,000 tonnes of waste per year, compared to 600,000 tonnes per year at the proposed incinerator in Belvedere.

Anaerobic digestion produces bio-methane, which would then be reformed into hydrogen, although not at the site. The biomethane would be fed into the natural gas pipeline system to be routed to a large SMR facility. By contrast, production of hydrogen from the syngas resulting from the gasification process will occur at the gasification site, as transporting the syngas “is not sensible.

Lhph22
Bus depots (red) and potential waste sites in London. Click to enlarge.

The report envisions the possibility of dedicated hydrogen pipelines transporting the hydrogen resulting from gasification to refueling sites. The viability of this scheme would be dependent on locating the hydrogen production facilities close to the potential areas of significant hydrogen demand (refueling depots), to minimize distribution distances and maximize flow rates.

The greenhouse gas emissions resulting from waste-to-energy projects depend on the composition of the waste stream. The biodegradable fraction of the waste is considered to be renewable and the CO2 emissions resulting from treatment of this part of the waste stream are ignored.

Based on an assumed biodegradable fraction of 65%, the non-renewable CO2 emissions of gasification would be 5.6 kg CO2 per kg H2. For reference, this compares to CO2 emissions from reforming of natural gas of around 9 kg CO2 per kg H2, Therefore, whilst gasification-to-H2 is not a zero-GHG emissions process, it compares favorably to fossil fuel-based production routes on this basis. In a situation where purely renewable routes are constrained due to resource availability or cost, this provides the next best option on the basis of GHG emissions.

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October 9, 2006 in Europe, Hydrogen | Permalink | Comments (10) | TrackBack (0)

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Comments

"waste-gas shift process to convert carbon monoxide to hydrogen"

should that read "water-gas shift process to convert carbon monoxide to carbon dioxide"?

We have finally solved the world's energy problems converting "carbon monoxide to Hydrogen"

They might as well make CH4 instead of H2. That way, they get to use the energy from Carbon, and not waste it. There are fuel cells in the R&D pipeline that use C as well as H.
_
http://en.wikipedia.org/wiki/Molten-carbonate_fuel_cell
http://www-cms.llnl.gov/s-t/carbon_con.html
http://www.netl.doe.gov/publications/proceedings/03/dcfcw/dcfcw03.html
_
They could possibly utilize carbon rich biofuels, like SVO, as well.
_
There are also the industrial, commercial, and residential uses for CH4 to consider.

Allen Z,
CH4 is being produced by anerobic fermentation of bio-degradable biowaste, which will be fed into natural gas pipelines. The non-biodegradable waste will be gasified to produce syngas, containing a mixture of H2 and CO. I would guess that it woould be easier to separate the H2 from the syngas, and the resultant CO be reacted with water (steam) using nickel catalyst to produce additional H2 and release CO2 (the water-gas shift process), rather than produce methane from the syngas. Using appropriate catalyst, it would be easier to produce methanol (wood alcohol) from the syngas, and then reduce it into methane, but that is a more circuitous route. Pyrolysis can be used to produce methane and other LPG (Liquefied Petroleum Gas)from biowaste by reduce the amount and duration of heating, but I suppose that the process is harder to control that gasification?
Beside, H2 is cleaner as a local short-range transportation fuel due to the absence of CO production, and more efficient in both FCV's and H2-ICE-hybrid electrics.

I think it is possible to feed the CO and H2 into an SOFC. CO becomes CO2 in the SOFC, so CO is part of the fuel. The output of the SOFC is CO2 and H2O. Since the process may not be complete, they use a turbine on the output to combust any remaining H2, which gives them even higher efficiencies. This is practical in an IGCC plant, but not in a car. So they could take CH4 and reform it.

Once we get our hands on that lovely CH4 we will use it to heat our homes in 95% efficient condensing boilers....or vehicles. No need to make it into H2, we canot afford the cost in CO2 and money of building such processing plants. Bio-methane is a great fuel.

Water-gas shift, yes. My typo. Product is hydrogen and CO2.

It sounds to me that this is a great project for plasma. Great Britian is the windiest country in Europe. Using plasma that is powered by wind is the best idea for waste to syngas. Getting rid of all that garbage and sewage and creating huge volumes of fuel with no pollution in the conversion process. Just the slag (cement if you will) as a by product is left. Now if we only recovered the metals from slag there would be no waste and large amounts of liquid fuel... :-)

Andy,
Ireland, Norway, and Iceland fit the bill too. There is a spar based offshore wind turbine under R&D at this moment, and the first application will likely be off Norway's coastline.

Since DME has an advantage of decomposition at lower temperature than methane and LPG, R&D for hydrogen source for fuel cell has been carried out. DME has a potential of feedstock for chemicals. DME to olefins is under development in Japan.

If you would like to know more on the latest DME developments, join us at upcoming North Asia DME / Methanol conference in Beijing, 27-28 June 2007, St Regis Hotel. The conference covers key areas which include:


DME productivity can be much higher especially if
country energy policies makes an effort comparable to
that invested in increasing supply.
By:
National Development Reform Commission NDRC
Ministry of Energy for Mongolia

Production of DME/ Methanol through biomass
gasification could potentially be commercialized
By:
Shandong University completed Pilot plant in Jinan and
will be sharing their experience.

Advances in conversion technologies are readily
available and offer exciting potential of DME as a
chemical feedstock
By: Kogas, Lurgi and Haldor Topsoe

Available project finance supports the investments
that DME/ Methanol can play a large energy supply role
By: International Finance Corporation

For more information: www.iceorganiser.com

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