Characterisation and variability of greenhouse gas emissions from biomethane production via anaerobic digestion of maize

Biomethane is a renewable gas that can be used in existing infrastructure to reduce dependency on natural gas and lower greenhouse gas (GHG) emissions. Policy incentives have promoted a rapid implementation of biomethane production facilities using anaerobic digestion (AD). A range of feedstocks are used in AD including crops which have a higher GHG burden than most wastes and residues. The purpose of this research is to characterise and assess GHG emissions from typical operational biomethane facilities. It is imperative that GHG savings are obtained therefore quantifying emissions using a robust methodology is paramount. This study uses maize as a case study utilising data from several farms and AD facilities. Results show that calculated emissions for biomethane production from maize are 33.8 gCO2e/MJ of biomethane using the Renewable Energy Directive (RED) methodology. Key emission sources include N-fertiliser production, soil N2O emissions, imported electricity use, and fugitive methane. Sensitivity analysis performed assessed key data inputs and demonstrates how input inventory parameters affect the GHG balance and highlights variability in results. For the desired GHG savings to be achieved it is important that operators minimise fertiliser use, use nitrogen inhibitors, minimise imported electricity, and undertake close management of methane loss. This paper shows that although biomethane is considered a renewable, low carbon fuel, the inputs need to be carefully managed in order to achieve thi

Fuel Standards Summary

This document aims to provide a comprehensive overview of the standards relating to fuel use in the UK. It can be used to gain an initial insight into which regulations must be considered when developing bio-based alternatives and the potential composition limits to meet current fuel quality specifications

Managing the Performance of Asset Acquisition and Operation with Decision Support Tools

Decision support tools (DSTs) are increasingly being used to assist with asset acquisition and management decisions. Whether these tools are “fit for purpose” will have both economic and non-economic implications. Despite this, the on-going governance of DST performance receives only limited attention within both the academic and industry literature. This work addresses that research gap. Within this paper a conceptual process for managing the operational performance of decision support tools is presented. The novelty of the approach is that it aligns with the ISO 5500x:2014 Asset Management Standard, therefore introducing consistency in the governance of DSTs with physical engineered assets. A case study of the UK’s National Grid Electricity Transmission (NGET) is used to inform the approach design. The evaluation demonstrates it to be both logical and useable within the context of NGET and they have expressed an intention to implement the approach within their business. A key finding of the research was that DSTs transcend functions and organisations. This is significant and can lead to a situation whereby performance and criticality are interpreted and measured differently. The introduction of a common approach for managing DST performance works towards improving consistency and creating a shared understanding