1. Forecasting EU Allowance Price Using Transactions of Central Entities

   Sotirios Dimos, Eleni Evangelatou, Dimitris Fotakis, Andreas Mantis, Angeliki Mathioudaki

   School of Electrical and Computer Engineering, National Technical University of Athens, Iroon Polytechniou 9, 15780 Athens Greece.

   Abstract: European Union Emission Trading System (EU ETS) can be analyzed as a transaction network. Under the rules of ETS, firms must hold enough allowances to cover for their annual emissions. Excess allowances may be traded or banked for future use. The allowance price is considered as an indication of how well the policy meets its objectives. We aim for a better understanding of the structure of the network and of the way the market dynamics affect the EUA price. Our findings indicate that there exists a small subset of nodes which emerges as core transactors and accounts to roughly 1.8% of the entire network participants. We call it All Time Almost Dominating Set, (ATADOM). Aiming to quantify its power, we provide a Vector AutoRegressive (VAR) model to forecast the EUA price. By using trading quantities restricted to ATADOM, along with significant price determinants from the literature, we find that it is possible to explain and to forecast EUA price by just tracking the behavior of the ATADOM set within EU ETS. Our work can be the basis of a compact evaluation tool to one of the most prominent environmental policies, the EU ETS.

   Keywords: EU ETS, Trading Network, Core-Periphery, Dominating Set, EUA Price Forecasting, Vector AutoRegression.

   Pages: 187 – 209 | Full PDF Paper

2. Comparison of the Biochemical Methane Potential of Different Organic Biomass

   Tavares, A.¹, Ziglioli, E. ¹, Remor, P. ¹, Cavaler, J. ¹, Alino, J. ¹, Bastos, J.¹, Edwiges, T.²

   1. Master in Environmental Technologies, Federal University of Technology – Paraná. Brazil Av. 85884-000, Medianeira/Brazil.
   2. Adjunct Professor in the Department of Biological and Environmental Sciences, Federal University of Technology – Paraná. Brazil Av.,85884-000, Medianeira/Brazil.

   Abstract: Anaerobic digestion is often used as an alternative treatment for biowastes. The methane potential and the biodegradability of different biowastes can be estimated by the biochemical methane potential (BMP) tests. This study aimed to determine the BMP and the enzymatic hydrolysis of different organic waste such as milk whey (MW), pig manure (PM), sugarcane bagasse (SB) and aquatic macrophytes (AM) (Pistia stratiotes). SB and AM were previously submitted to particle reduction size (< 10 mm) and SB was oven-dried (60 °C for 24 hours). The assays were performed in 125 mL glass bottles at 37 °C. Biogas composition was determined by gas chromatography and the results were evaluated using analysis of variance and Tukey test for mean comparisons (p < 0.05). The highest BMP was observed for MW (314 L_NCH₄ kg VS^-1) followed by PM (301 L_NCH₄ kg VS^-1) and SB (249 L_NCH₄ kg VS^-1) and AM (43 L_NCH₄ kg VS^-1). The high variation in the methane potential of the studied substrates is related to their different chemical composition and biodegradability rates. It is suggested that co-digestion using a mixture of substrates could increase methane production, since it favors the synergistic effects, increases the methane content and improves the operation of the biodigester.

   Keywords: agricultural waste, biogas, BMP, anaerobic digestion.

   Pages: 210 – 215 | Full PDF Paper