Background Solid waste disposal on land accounts for some 2.4% of total EU greenhouse gas emissions. The two main gases emitted are carbon dioxide (CO2) and methane (CH4) as a result of the biodegradation of carbon compounds by anaerobic methanogenic bacteria. The rate of CO2 and CH4 emission increases with the amount of biodegradable waste going to landfill sites. Objectives The main objective of the GHERL project was to reduce the greenhouse effect resulting from biogas emissions from a municipal solid waste landfill. The reduction was planned to be achieved by means of CO2 capture from landfill gas in a final stable and solid form. This final solid compound was expected to be a simple scrap, which could then be disposed in the landfill itself. It was also to be a product useable as input in the chemical industry or agriculture. Results The GHERL project achieved its full set of objectives and expected results. It implemented a successful process for removing CO2 from landfill gas. The process is based on chemical absorption with appropriate reactant solutions and enabled capturing the CO2 in solid form. A prototype able to treat a part of the CO2 produced by the landfill was constructed to demonstrate the feasibility of the process. The prototype was installed on a landfill site currently managed by one of the project’s partners. The plant basically consists of a packed column where an aqueous solution of potassium hydroxide (KOH) come into contacts with the CO2 contained in the landfill gas. KOH and CO2 react, forming potassium carbonate (K2CO3), which can be recovered in solid form. An overall assessment of the process – including technical, economical and environmental aspects - was carried out. Applying the proposed process, 96.7% of the CO2 present in the landfill gas is captured, representing a reduction of 8-10% Nm3. Potential environmental benefits of a full-scale plant are substantial. A study conducted on the potential reproducibility of the process concluded that there are no technical limitations for its replication in different sites. A comprehensive evaluation of the market potential of the process was also produced, finding that: The application of the process does not require the development of special devices since most of the required components are fairly market standard This process can be used for any source of CO2, like for example biogas from anaerobic digestion It could be used for the production and selling of K2CO3, a product which has e.g. several applications e.g. in the chemical industry. Thereby primary fuel (methane) used to produce K2CO3 with the traditional method can be saved, and selling K2CO3 could enable to cover the investment and operation expenses, depending on the price of KOH and K2CO3 Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).