Renewable Gas

Comfort-loving citizens in the Northern Hemisphere have good reason to take an interest in the future of gas, particularly since the demand for energy from Natural Gas in winter can be several times higher than the consumption of electrical energy (DECC, 2014a), and the rates of insulation renovations for old, draughty buildings can be slow. Unlike electricity, it is possible to store gas from season to season, making it a practical energy vector; extended storage means that gas production can be averaged out throughout the year. However, the use of Natural Gas in the long term is in some doubt as it is a fossil fuel and its combustion disturbs the deep geological carbon cycle, thus contributing to global warming. It is therefore appropriate to consider whether there might be viable low carbon alternatives to Natural Gas. Biogas, naturally occurring from the microbiological decomposition of biomass, has much to offer, but its advancement may well be hampered by changing patterns of land use, including constraints imposed by climate change. Enhanced and advanced biogas processing techniques could compensate, giving higher yields of gas from biomass (e.g. Luo and Angelidaki, 2012), although gas produced with any biological processing steps could remain slow. Consequently, industrially manufactured low carbon gas holds the most promise in terms of production volumes, although its development depends on adaptations and integration across several sectors of the economy.

Climate change is an energy problem — we cannot solve climate change without solving energy. Energy change is not just a matter of convincing the world’s energy producers to alter the resources they use; or manufacturers to focus on energy Efficiency; or consumers to alter their energy use behaviours. To meet greenhouse gas and particulate emissions targets, and manage water consumption, can never be merely a political, regulatory question, and arguably this would anyway require more organised, committed global governance than currently in evidence. The privately owned energy sector cannot be assumed to be in sufficient good health to respond to regulatory or market change, despite excellent stock market performance. It could be said that the strong value of shares in energy companies and a recently terminated decade of mounting energy commodity prices have created a distraction, a diversion from fundamental fault lines. Studies into energy increasingly alight upon concerns about the projections for future global energy production and consumption, and questions about the life cycle renewal of energy supply and infrastructure in an atmosphere of low economic growth.

To minimise the risk of low investment levels in energy systems, it could be optimal to chart a course based on what is currently working, rather than overreaching. In a low growth global economy, big shifts in investment targets and large hikes in capital expenditure are painful, and so it is most pragmatic to work with what we have already got and expect only low threshold changes.

Burning vapour flaring out of the ground has been a cause for marvel or even veneration for centuries (Aminzadeh et al., 2001; Berge, 2011, 2013; Dumas, 1859; Etiope, 2010; Etiope et al., 2013a, 2013b; Forbes, 1939, 1958; Galetti, 2005; Hosgormez, 2007; Hosgormez et al., 2008; Ingersoll, 1996; Jackson, 1911; Kamali and Rezaee, 2012; Ker Porter, 1822; Le Strange, 1905; Lockhart, 1939; Marvin, 1884; Pliny, c. 77; Spulber, 2010; Strabo, 7 BC; Thwaite, 1889; Verma et al., 2004; Waples, 2012, Pages 7–9; Yergin, 1991; Ziegler, 1920); however, the widespread use of Natural Gas as an energy fuel only came about after gas manufactured from coal and other feedstocks had become commonplace (Tarr, 2009).

A global warming of the troposphere, the lower part of the atmosphere closest to the Earth’s surface, has been causally attributed to humankind’s burning of fossil fuels, cement production and other industrial manufacture, deforestation and other land use change activities. The thermal inertia of the world’s oceans means that even were anthropogenic carbon dioxide emissions to be completely curtailed today, there is enough added heat in the Earth system as a whole, and heightened levels of greenhouse gases in the atmosphere and the oceans, to continue warming the troposphere and land surface of the planet, perhaps for hundreds of years (IPCC, 2013). The risks of the onset of damaging climate change resulting from this “commitment” to further global warming, in addition to that already experienced, are so severe that measures are being implemented worldwide to stem net greenhouse gas emissions to air. Action to curtail what is known as “Black Carbon” — particulate emissions from the burning of wood and fossil fuels, in the very near term, could help to curb short-term atmospheric warming, and provide a window of opportunity to address the more long-term threats from the most significant greenhouse gases: carbon dioxide, methane and nitrous oxide (N₂O) (Boucher and Reddy, 2008; Client Earth, 2012; Highwood and Kinnersley, 2006; JRC, 2014; Minjares et al., 2013).

In the development of a Renewable Gas system using the generic design elements previously described, there are a number of “pinch points” — process steps which could benefit from further research and development where the current articulations of the technologies have snags or pitfalls.

The British Government, in language similar to that used by other governance bodies, have identified an energy “trilemma”: of having to design policy that meets the needs of the combined criteria of energy security, climate security and economic stability (DECC, 2014b). Energy policy should build in safeguards for energy supply and energy demand control; meet the Carbon Budgets set out by the Climate Change Committee under the articles of the Climate Change Act of 2008 (CCC, 2013), whilst ensuring affordable energy provision, and sustaining energy markets, without destabilising the wider economy. It may seem that the way forward for policy points in several different directions at once, like a city centre waymarker; however, a common framework for policy can be constructed, provided that counter-productive requirements are removed and enabling measures adopted.

Significant change in the hydrocarbon energy industry appears inevitable, and it can be simply summarised as a progressively worsening ratio of hydrogen to carbon molecules in the processes that provide liquid and gaseous fuels. The more complicated the fossil fuel resources brought to refinery and processing plant, the more “churn” is required to raise the hydrogen content and thus the energy value of the final products, which implies rejecting excess carbon, with inefficiency and therefore cost ramifications. In addition, without careful consideration of the path that the rejected carbon molecules take, this could have serious greenhouse gas emission implications. The current way to address the problem of the worsening hydrogen-to-carbon ratio is to contribute the hydrogen from thermochemically treated Natural Gas to the processes at oil refinery, although this also contributes a certain amount of fossil carbon to the system, which will be disposed of as increased carbon dioxide emissions. An improvement would be to introduce emissions-neutral carbon from biomass into the processes being used to form hydrogen. Although this does not correct the overall balance of hydrogen and carbon, it does mitigate against net greenhouse gas emissions. A further transitional step would be to introduce hydrogen from carbon-free sources, such as water.