A1 Results

Action A1 started at the beginning of the project (January 2010) and was concluded at the end of September 2010.

The Technical Report of Action A1, with the detailed results of the preliminary evaluation, is now available.

The aim of this group of actions is to make the preliminary evaluations necessary for applying the two proposed methods to the specific case of landfill gas/biogas up-grading. In both the cases the crucial point is to find the correct solid residues able to realize the accelerated carbonation of carbon dioxide contained in the landfill gas/biogas.

With this aim different types of solid residues have to be analyzed. The first candidate for the processes are the bottom ashes (BA) that every day arrive at the landfill – where the pilot plants will be installed – from a Waste-to-Energy plant in the proximity. These need to be analyzed in order to identify their main physic-chemical and mineralogical characteristics.

Concerning the alkali absorption with regeneration method, a preliminary theoretical analysis of the first part of the process – the absorption step – need to be performed – also with the support of devoted technical software – in order to identify the alkaline compounds most suitable for carbon dioxide chemical absorption from landfill gas/biogas. This sub-action have been carried out by DEF. After obtaining these theoretical results, some tests have been carried out at the existing absorption pilot plant, in order to produce load solution samples. This sub-action was carried out by DEF, at the existing absorption pilot plant at Casa Rota Landfill, managed by CSAI.

At the same time a laboratory characterization of different solid residues was performed with the aim of identifying their potential of regenerating the carbon dioxide load solution. CSAI sent a small sample of BA (few kg) to UNIROMA for their characterization. This sub-action was carried out by UNIROMA at its experimental facility laboratory. Also UNIROMA performed some laboratory tests in order to reproduce the regeneration liquid/solid contact process. These preliminary experiments were necessary in order to establish the required contact time for the specific solid residues available and hence for the definitive accurate sizing of the regeneration reactor (carried out in action 2), as well as to identify the influence of the operating parameters and select the operating conditions (temperature; liquid/solid ratio; concentration).

Concerning the BABIU process, in this first part, data about carbon dioxide - and hydrogen sulphide - binding capacities of the bottom ashes available at the CSAI landfill site (coming from a Waste-To-Energy plant in proximity) were obtained by means of a laboratory-scale pilot plant already available at the laboratory facilities of ABF-BOKU. CSAI collected about 300 kg of bottom ashes – accepted at the landfill - and organized their transport to Vienna. This sub-action is necessary also to establish the required contact time for the specific solid residues available and hence for the definitive accurate sizing of the BABIU reactor (carried out in Action A2). This sub-action was carried out by ABF-BOKU at its experimental facility laboratory.