Carbon Dioxide Capture from Landfill Gas

Within the frame of an EU financially supported project - LIFE05 ENV/IT/000874 GHERL – a pilot plant was set up in order to demonstrate the feasibility of applying chemical absorption to remove and capture carbon dioxide from landfill gas by means of an aqueous solution of potassium hydroxide, with the final aim of producing potassium carbonate. Potassium carbonate is a product which has several applications in the chemical industry if obtained with adequate quality (e.g., crystal industry, special glass production, potassium salts, inks and pigments, detergents, food industry, waste gas treatment). It can be sold as a pulverised solid, or in aqueous solution. The aim of the project was to capture carbon dioxide from landfill gas in order to improve its quality and to obtain a gas very similar to natural gas, which can be introduced into the grid for common use, or even burnt in conventional engines. Several tests were carried out at the pilot plant, which was located at a landfill site, in order to feed it with a fraction of the on-site collected landfill gas. The results of the experimental campaign are reported, explained and commented in the paper. Also a preliminary economic evaluation is presented.