CO2 abatement costs of greenhouse gas (GHG) mitigation by different biogas conversion pathways

Publication Type

Journal contribution (peer reviewed)

Authors

Rehl, T; Müller, J

Year of publication

2013

Published in

Journal of Environmental Management

Pubisher

Elsevier

Band/Volume

114/

DOI

10.1016/j.jenvman.2012.10.049

Page (from - to)

13-25

Keywords

greenhouse gas emission

Biogas will be of increasing importance in the future as a factor in reducing greenhouse gas emissions
cost-efficiently by the optimal use of available resources and technologies. The goal of this study was to
identify the most ecological and economical use of a given resource (organic waste from residential,
commercial and industry sectors) using one specific treatment technology (anaerobic digestion) but
applying different energy conversion technologies. Average and marginal abatement costs were calculated
based on Life Cycle Cost (LCC) and Life Cycle Assessment (LCA) methodologies. Eight new biogas
systems producing electricity, heat, gas or automotive fuel were analyzed in order to identify the most
cost-efficient way of reducing GHG emissions. A system using a combined heat and power station (which
is connected to waste treatment and digestion operation facilities and located nearby potential residential,
commercial or industrial heat users) was found to be the most cost-efficient biogas technology
for reducing GHG emissions. Up to V 198 per tonne of CO2 equivalents can be saved by replacing the
“business as usual” systems based on fossil resources with ones based on biogas. Limited gas injection
(desulfurized and dried biogas, without compression and upgrading) into the gas grid can also be a viable
option with an abatement cost saving of V 72 per tonne of CO2 equivalents, while a heating plant with
a district heating grid or a system based on biogas results in higher abatement costs (V 267 and V 270
per tonne CO2 eq). Results from all systems are significantly influenced by whether average or marginal
data are used as a reference. Beside that energy efficiency, the reference system that was replaced and
the by-products as well as feedstock and investment costs were identified to be parameters with major
impacts on abatement costs. The quantitative analysis was completed by a discussion of the role that
abatement cost methodology can play in decision-making.