|Title||Farm-scale bio-power-to-methane: Comparative analyses of economic and environmental feasibility|
|Author(s)||Bekkering, Jan; Zwart, Kor; Martinus, Gerard; Langerak, Jort; Tideman, Jeroen; Meij, Tineke van der; Alberts, Kees; Steenis, Machiel van; Nap, Jan Peter|
|Source||International Journal of Energy Research 44 (2020)3. - ISSN 0363-907X - p. 2264 - 2277.|
|Department(s)||Sustainable Soil Use|
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||bio-methanation - biogas - electrolysis - energy efficiency - greenhouse gas emission saving - supply chain optimisation|
Power-to-gas technologies are considered to be part of the future energy system, but their viability and applicability need to be assessed. Therefore, models for the viability of farm-scale bio-power-to-methane supply chains to produce green gas were analysed in terms of levelised cost of energy, energy efficiency and saving of greenhouse gas emission. In bio-power-to-methane, hydrogen from electrolysis driven by surplus renewable electricity and carbon dioxide from biogas are converted to methane by microbes in an ex situ trickle-bed reactor. Such bio-methanation could replace the current upgrading of biogas to green gas with membrane technology. Four scenarios were compared: a reference scenario without bio-methanation (A), bio-methanation (B), bio-methanation combined with membrane upgrading (C) and the latter with use of renewable energy only (all-green; D). The reference scenario (A) has the lowest costs for green gas production, but the bio-methanation scenarios (B-D) have higher energy efficiencies and environmental benefits. The higher costs of the bio-methanation scenarios are largely due to electrolysis, whereas the environmental benefits are due to the use of renewable electricity. Only the all-green scenario (D) meets the 2026 EU goal of 80% reduction of greenhouse gas emissions, but it would require a CO2 price of 200 € t−1 to achieve the levelised cost of energy of 65 €ct Nm−3 of the reference scenario. Inclusion of the intermittency of renewable energy in the scenarios substantially increases the costs. Further greening of the bio-methanation supply chain and how intermittency is best taken into account need further investigation.