Ilze Dzene, Francesco Romagnoli, Gundega Seile, Dagnija Blumberga

Comparison of different biogas use pathways for Latvia: biogas use in CHP vs. biogas upgrading

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Abstract

In order to contribute to the European 20-20-20 targets, Latvia has committed to increase the share of renewable energy in the final energy consumption from 34.9% in 2005 up to 40% in 2020. Within these ambitious targets biogas will play important role. Biogas can be used following different pathways: direct combustion with the production of only heat, combined heat and power (CHP) generation, or it can be upgraded to biomethane and later used as vehicle fuel or injected in the natural gas grid. In this light an important question is raising about what is the most feasible pathway of the biogas use. The assessment of the feasibility and performance of a single pathway cannot be based only on economic criteria like costs and related economical benefits. Therefore in this study the assessment is done through a multidisciplinary approach that involves not only economical, but also environmental and social perspectives. The main purpose of this study is devoted to the analysis of different biogas use pathways under a specific set of proper criteria based on a literature review. Scenarios under assessment include direct biogas combustion, use of biogas in a CHP system, and biogas upgrading to biomethane. The identified set of criteria is applied to the Latvian biogas market as a case study in order to provide a consistent and holistic final overview.

Keywords: biogas pathways; biomethane; biogas upgrading; CHP; multi-criteria analysis.