Technology Idea of the Week

This week: is there a future for methane fuel cells? Methane hydrates have featured quite a lot recently while I researched for my posts on Arctic natural resources and in Anson Mackay's lecture on the crysosphere. It seemed deserving as this weeks technology focus!

Fuel Cells - A very brief introduction! 

• Convert chemical energy into electricity by an oxidising reaction
• Require a constant fuel supply 
• The ideal fuel is hydrogen because it doesn't produce greenhouse gases but the technological challenges in its cost and storage mean this currently not viable (Steele, 1999, Nature)
• Currently, the best fuel options are hydrocarbons (methane) and alcohols (methanol).  

Methane Hydrates

• Methane hydrates (clathrate) are crystalline solids composed of a mixture of water and light natural gas (methane, carbon dioxide, ethane). They are found in the shallow lithosphere (<2000m deep) where the surface temperature is less than 0 °C (Kvenvolden, 1993, Review of Geophysics)
• There are substantial natural deposits of methane hydrates in deep ocean sediments, permafrost and under frozen lakes. It is estimated that the global volume of methane hydrate is 10¹⁵ to 10¹⁷ cubic metres of methane which represents 53% of all fossil fuels ((Demiras, 2010, Energy Conservation and Management). The distribution of organic carbon can be seen in the image below. 

Distribution of organic carbon on earth (excluding kerogen and bitumen).
Source: Demiras, 2010, Energy Convservation and Management)

Advantages of Methane Fuel Cells

• Substantial deposits - it is estimated that the global volume of methane hydrate is 10¹⁵ to 10¹⁷ cubic metres. Deposits are found in widespread geographical locations including US permafrost, Lake Baikal in Siberia and Arctic sediments. (Demiras, 2010, Energy Conservation and Management)
• Low carbon energy - methane is a less carbon intensive fuel than coal or oil: it produces approximately half the amount of CO2 than coal for equivalent volumes. This can be seen the equation below. Therefore using methane hydrates as an energy source could help reduce anthropogenic emissions of carbon dioxide which may contribute to the greenhouse effect. 

Top equation - the combustion of coal. Lower equation - the combustion of methane hydrate
Source: Demiras, 2010, Energy Convservation and Management)

The Challenging side of Methane Fuel Cells

• Location and access - finding the deposits requires high level seismic imaging, we do not have detailed enough resolution for some deposits. In addition the deposits often cross national boundaries or are in international territories. This raises a lot of geopolitical issues in terms of researching the site and rights over the resources. (Kvenvolden, 1993, Review of Geophysics)
• Extraction - the gas can expand 160 times its volume as it is brought to the surface and is de-pressurised. This can cause explosions and leaks of methane gas (CH4) which contributes to the greenhouse effect. We currently need to do further research into drilling technology to ensure safe extraction of methane hydrates. (Demiras, 2010, Energy Convservation and Management)

It is possible...

In March of 2013, a Japanese drilling company successfully produced gas from frozen methane hydrates from the ocean floor. For equal volumes, this deposit holds 164 times the energy of conventional gas (NewScientist, 2013). The deposit is in the Nankai trough and could be a game changer for Japan's energy supply. Investigation into methane hydrates was fast tracked by the Japanese government after the Fukushima nuclear power disaster. Here is a film of the methane hydrate extraction in Wellington by a team of German Scientists (the video is in English)! 

In conclusion, methane hydrates could be a really important step in meeting our energy needs over the next 100 years. The ultimate goal still remains as the production of commercially viable hydrogen fuel cells. 

Meet the Frackers - Part 2

After my introduction to fracking last week I am going to look at both sides of the fracking debate in a little bit more detail. Fracking is the process where fluid is pumped into rock at high pressure which causes the rock to fracture. This creates more space within the rock and allows oil and gas to percolate through the formation therefore it can be pumped to the surface and extracted.

Figure: United States Environment Protection Agency

Arguments supporting Fracking

• Domestic production of energy means some countries may be able to become self-sufficient in energy production and even export it.
• It generates industry, employment and allows the country to control its energy prices, hopefully in favour of the consumer!
• For the UK, there is huge potential for fracking. A recent report by the Department of Energy and Climate Change estimated potential reserves of approximately 1466bcm (DECC 2013 Fracking Report). To put this into context, annual gas consumption for the UK is 77bcm. Therefore giving us 20 years of energy, give or take a few!  
• Breakthroughs in technology may help to reduce the environmental impacts caused by heavy water usage and infrastructure in extraction.
• Chemicals used can be nontoxic and methane has a shorter half-life than CO2 so will remain in the atmosphere for a shorter period of time (Howarth, Ingraffea and Engelder, Nature 2011).
•   There is huge potential as an energy source globally as well! This could help us bridge the gap between renewable energy sources. 

Figure (Forbes 2012)

The Anti Fracking Campaign

•   It not a ‘clean’ energy source and produces fossil fuels which may contribute to global warming. It is slightly lower in carbon emissions than coal and oil (Tyndall Centre 2011). 
• Minor earthquakes can be produced, up to this date they have ranged from 1-3.8 magnitude (Davis et at 2013). See previous Part 1 for more detail.
• Heavy water usage which impacts the environment and costs a lot of energy to be transported to the site. Depending on the site, a well can use up to 20 million litres of water. (Howarth, Ingraffea and Engelder, Nature 2011)
• Many of the chemicals used in fracking are toxic or carcinogenic. There could be leakage of these from the wells due to bad practise or inherent problems with the technique. A study of 68 wells in Pennslyvania showed a dramatic increase in methane levels (and 75% of lakes very over contaminated levels) with proximity to the extraction site (Environmental Health Perspective 2011)
•  It is a very new technology to be adopted on such a large scale. Research on the impacts of fracking is minimal and has only appeared in two peer reviewed journals.
• ‘Old fashioned’ approach. Fracking is still utilising fossil fuels and therefore could distract energy companies and governments from focusing on long term solutions.

Which Side of the Fence? 

There are a lot of points on either side and essentially seems to come down to the huge potential for cheap energy vs the unknown and potentially catastrophic impacts of fracking. One of the most striking things I found doing this post is the gaps in our understanding of fracking and of course this is something campaign groups such as Frack Off have focused on. Despite this, I think that the potential for energy supply and positive improvements in technology mean that fracking will be and should be a key player in the energy market.