Environmental Engineering Reference
In-Depth Information
9
Energy flows in biogas plants: analysis and
implications for plant design
FRANK SCHOLWIN,
Institute for Biogas, Waste Management and Energy, Germany and
MI CHAEL NELLES , University of Rostock, Germany
DOI: 10.1533/9780857097415.2.212
Abstract: Biogas plants offer a positive contribution to greenhouse gas
mitigation and renewable energy supply; an energy balance is key to the
evaluation and optimisation of this contribution. This chapter discusses
the energy demand of biogas plants and methods for its evaluation.
Suggestions are also put forward for the optimisation of the energy
balance, including the reduction of parasitic energy demands and the
avoidance of energy losses. It is suggested that biogas technology will be
able to fulfil forthcoming demands for increased energy efficiency and
sustainability.
Key words: energy balance, heat demand, electricity demand, fuel
demand, energy loss reduction.
9.1
Introduction
The desire for economic and ecological efficiency will increasingly lead to
the application of a specific biogas technology on a commercial scale.
Investors seek to compare and evaluate technological prospects not only on
the basis of investment and operational costs and biogas yields, but also on
the basis of greenhouse gas emission reduction (carbon credits) and
renewable energy supply targets. The energy efficiency of a biogas plant
must therefore be evaluated and optimised using an energy balance
approach. Unfortunately, in many cases, reliable data for the comparison
of different technologies are unavailable. Moreover, most investigations
focus only on electricity or heat demand, while fuel demand for transport is
generally ignored. Experience has demonstrated that there is a relationship
Search WWH ::
Custom Search