Friday, 25 July 2014
ECAs (emission control areas) are stimulating debate in the shipping industry about how, most cost effectively, to respond. Arguments are polarising around scrubbers or LNG. The latter has a significant number of advocates and for good reason - it is lower in sulphur oxide, nitrogen oxide and particulate matter and comes at a more competitive price than marine gas oil (MGO), the alternative for vessels operating in ECAs.
LNG, however, is a far from perfect fuel from a greenhouse gas perspective. Methane slip, where partially combusted gas escapes into the atmosphere, is a very significant issue. LNG is a potent greenhouse gas - about two orders of magnitude as powerful as CO2 and this offsets many of its advantages. Significant efforts are being made in the industry to reduce methane slip, and to talk down the impact, the argument being that methane slip from the marine sector is significantly less than from other activities such as agriculture, mining and ‘natural seepage’. This rather evocatively unpleasant term relates to methane produced from food waste, sewerage and manure. This source of methane presents an opportunity.
Through a process of anaerobic digestion these unpleasant sources of energy can be converted into Liquid Bio-methane, bio-gas, and, after cleaning, this is the same as LNG. Bio-gas can be spiked into any LNG grid that evolves in response to maritime bunker demand and through a process of back-to-back certification ship operators can demonstrate they are operating on renewable fuels - which may prove to be lucrative as we move into a fossil-fuel depleted future.
Since bio-gas depends on waste as a feedstock it does not reduce land available for agriculture and so avoids the food/fuel debate whilst making good use of methane producing ‘seepage’. Regardless of the unlimited supply of feedstock bio-gas will be in limited supply because it is recognised as a valuable fuel of the future and all forms of transport are seeking practical non-fossil solutions. Bio-gas is not currently available in volume but it’s development is being eagerly trialled by land transport operators in automotive and rail. Rather pointing the finger of blame at other sectors shipping, as the most efficient form of transport, should be staking a strong claim for future use of bio-gas and and claiming superiority by actively engaging in supporting the development and adoption of bio-gas across the global fleet.