Experts see 2007 as the year of biogas; biomethane as a transport fuel

Biomethane or biogas (CH4), chemically the same as natural gas yet available from essentially any kind of organic waste, is rapidly emerging as a viable renewable alternative to fossil fuels and could be the next 'hot' fuel this year. Biomethane's fundamental production efficiencies make it competitive with such better known liquid fuels as biodiesel and ethanol, even though vehicles need special fuel tanks to handle it. That's the word from Fleets & Fuels, a newsletter on advanced technology vehicles and the fuels that drive them. "We're extremely excited about the potential for biomethane," says Fleets & Fuels editor Rich Piellisch. "Its potential production efficiencies are terrific, and not at all dependent on the fossil fuel markets."

Those who have read Biopact on a regular basis have seen that we didn't have to wait for 2007 to see a biogas boom, because 2006 already did its part. Allow us to present a quick overview of developments and topics we devoted to the subject:

Biogas applications
The large-scale use of biomethane made headlines in Europe when several cities implemented innovative biogas projects that deliver power and heat to households. The gas can be used like natural gas in large existing power plants, or in smaller, dedicated, and highly efficient combined heat-and-power plants. In Germany, a unique large biogas digesting facility delivers biomethane to a city via a dedicated pipeline; the biogas maize (the feedstock) is irrigated with waste-water from the city, thus creating a loop of waste-streams that result in a very clean energy system (earlier post). In Austria, a pilot project is underway to build a genuine biorefinery around biogas, in which lactic acid byproducts yield the chemical building blocks for high value added green chemistry. The refinery-cum-power plant will deliver heat, electricity, specialty products and bioplastics (earlier post).

In an equally exiting project, the world's first large biogas fuel cell is delivering power and heat to a German district, in what is probably the most efficient energy system currently in operation anywhere (earlier post).

When produced on a large scale, biogas can also simply be fed into the natural gas grid and enter the energy mix without consumers noticing it. A select number of European firms (such as energy giant E.ON and world leading biogas plant manufacturer Schmack) has already begun doing so, while farmers who generate excess biogas on their farms make use of incentives to sell the electricity they generate from it to the main power grid. In Germany alone, some 5000 farmers did exactly that, last year. (For the stories on biogas as an automotive fuel, see below).

Biogas crops
Several European countries are experimenting with dedicated biogas energy crops, such as newly bred grass varieties (Sudan grass and tropical grass hybrids) or biogas 'super maize' developed in France. The crops are developed in such a way that they ferment more easily and yield enough gas when used as a single substrate.
Sweden is making a large investment in producing biogas from wood chips - a process that is more efficient and considerably less costly than the production of cellulosic ethanol (which has not yet achieved commercial status) (earlier post):

Contrary to first-generation ethanol crops, biogas crops can be used whole, which allows for the use of far more biomass per hectare. The conclusion of a German life-cycle analysis is that of all biofuels (including cellulosic ethanol, biomethanol and BTL-fuels), the production of biogas from dedicated crops yields more energy per hectare than any other biofuel production path and generates far less CO2 (earlier post):
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Biogas production technologies
The technologies to purify biogas to natural gas standards (96% methane content) are now available, wich allow the gas to be fed into natural gas grids and onwards to fuel stations. One of those technologies involves the use of algae which scrub CO2 and trace chemicals out of the biomethane, thus making the purification process itself green and renewable (earlier post). High-tech sensors have been developed that make monitoring the fermentation stages of organic feedstocks easier and the production process safer (earlier post).
Manufacturers of farm equipment are jumping on the booming biogas industry, by developing dedicated machines that can harvest grass (a preferred feedstock) more easily (earlier post).

Biogas-capable vehicles and infrastructures
In theory, all compressed natural gas (CNG) vehicles, of which there are some 5 million on the road worldwide, can use compressed biogas (CBG). Several car manufacturers however have developed multi-flex vehicles that explicitly cater to the use of biogas. Amongst them Fiat whose 'Multipla Multi-Eco' vehicle is a tri-fuel, that operates on two types of biofuel (ethanol and biogas) and ordinary gasoline (earlier post). In India, car manufacturers are looking into developing biogas-hybrids (earlier post).

In Europe, several projects are showing success with the use of biogas in public transport. The BiogasMax program that covers the French city of Lille and the Swedish city of Linkoping showed that the gas can be used in a very beneficial way in buses and large trucks (e.g. waste collecting trucks), because they allow for the concentration of dedicated refuelling infrastructures. Lille now has more than 100 biogas buses, Linkoping has 65. The project in Lille has inspired a developing country, the island state of Mauritius, whose state-run bus company will start using biogas in the country's largest public transport fleet (earlier post).

Last year, Sweden launched the world's first biogas train, a story well covered by mainstream media, while at the other side of the planet, in Australia, a project is underway which aims to utilize the vast stream of easily fermentable biomass released by a large banana plantation, for biomethane production. The gas will power all main farm equipment on the plantation (earlier post).

When it comes to the creation of an infrastructure that can service ordinary car users, major developments are underway as well. German energy giant E.ON is building over 150 fuel stations, supplied by its own biogas production facilities (earlier post). In 2006, Austria opened its first biogas fuelling stations (earlier post), Germany did so too (earlier post).

The construction of dedicated infrastructures is one of the biggest hurdles to get compressed biogas accepted as a main biofuel. But when we look at some developing countries, we see that it is not impossible. Pakistan, for example, succeeded in getting over 1 million CNG-capable cars on the road in under two years time, in a crash program that involved the creation of CNG-refuelling stations and the conversion of cars (earlier post). Compressed Biogas (CBG) could be integrated into such a CNG infrastructure with no major investments.

Biogas advantages and potential
The European Union commissioned a well-to-wheel study of over 70 different fuels, both renewable and fossil fuels. Its conclusion: biogas is the most carbon-neutral of all fuels (in some cases it is carbon-negative), and if derived from dedicated biomethane crops, it yields more energy per hectare than all other non-tropical biofuels (including cellulosic ethanol).

In Germany, a biogas pioneer who took up a role of energy advisor to the Federal Government, estimated that the potential of biogas is so great that it can replace all natural gas imports from Russia by 2030 (earlier post). The German Biogas Association is equally optimistic but puts the potential at half that (earlier post).

Since large-scale production of biogas is less technology intensive than other biofuels (certainly compared to next-generation green fuels), it presents a highly suitable component for a new energy paradigm for the developing world. Many countries in the South do not have a full-fledged fossil fuel infrastructure in place yet, so they still have the option of introducing CNG/CBG cars and infrastructures on a large scale. Biogas could become an important element of an 'energy leapfrogging' strategy in the South - Pakistan's successful CNG crash program makes the case, as does Mauritius's switch to biogas for its public transport bus fleet.

One advantage of biogas that might become important in the future, is that it can be used to make hydrogen in an economic way. Hydrogen is currently made almost exclusively from natural gas, which is why it isn't a 'clean' and 'carbon neutral' fuel. If made from electrolysis, hydrogen production is extremely energy intensive and very costly. So the idea is to use the same processes now used to make the hydrogen from natural gas, but only to quit using the fossil fuel and replace it with the green gas.

Finally, and on another note, biogas from dedicated energy crops offers an avenue towards the creation of radically carbon negative energy systems, by coupling carbon storage technologies to biogas power plants. In fact, such 'Bio-Energy with Carbon Storage' (BECS) systems are our surest bet to geo-engineer the planet in case it were to undergo 'abrupt climate change' (earlier post).


In short, this incomplete overview of stories on biomethane shows that, to us, 2006 already was fuelled by biogas. But let us listen to how Fleets & Fuels assesses the prospects for this year. "We're extremely excited about the potential for biomethane," said Fleets & Fuels editor Rich Piellisch. "Its potential production efficiencies are terrific, and not at all dependent on the fossil fuel markets," Piellisch said. "And, because its production actually consumes potent greenhouse gases that are often vented to the atmosphere, there's a double benefit in terms of climate change mitigation.

"The single investment in suitable vehicles pays off many times during the life of those very clean vehicles.

"Biomethane is fast proving itself in Europe, and entrepreneurs and policymakers in the United States are becoming aware of it too," Piellisch added.