Use of circular economy and cascading bioenergy systems in ensuring sustainable biogas production
Renewable energy is not always sustainable energy.Sustainable has many meanings but one quantifiable definition relates to a percentage reduction in greenhouse gas emissions as compared to the fossil fuel displaced on a whole life cycle basis.Within the EU,sustainability was considered initially as a 30% reduction in emissions,rose to a 60% reduction,and in a 2050 scenario may well be of the order of an 80% reduction or larger.Bioenergy systems tend to include for a number of steps,which have significant energy (and carbon) inputs,be it in cultivation of energy crops,the collection and transportation of substrates to the bioenergy facility,the parasitic demand in the conversion of biomass to a suitable energy vector and the transportation of that vector to the end user.In a future world of decarbonised energy,many bioenergy and biofuel systems may not be deemed sufficiently sustainable.Biogas may have an advantage in this regard.In general the literature would suggest that gaseous biofuel vectors are more energy efficient than liquid biofuel vectors.Treating waste to produce biogas is suggested as sustainable and should meet an 80% reduction in emissions,depending on the intricacies of the system.Beyond wastes the ability of biogas systems to meet in excess of 80% emissions savings is difficult and may require very careful system optimisation.The literature would suggest that circular economy routes and cascading bioenergy systems may aid in this process.Green gas is a concept whereby all the uses of natural gas may be undertaken by green gas.The natural gas grid instead of being considered obsolete in a new decarbonised renewable energy industry may in essence become a crucial renewable energy infrastructure which can distribute renewable electricity,heat and transport from source to end user.The challenge is to ensure the green gas is sustainable.
Biogas sustainability algal biogas cascading bioenergy circular economy
J.D.Murphy D.Wall
MaREI Centre, Environmental Research Institute, University College Cork, Ireland
国际会议
The 15th IWA World Conference on Anaerobic Digestion( 第15届IWA世界厌氧大会)
北京
英文
791-794
2017-10-17（万方平台首次上网日期，不代表论文的发表时间）