Hongrapipat, J.Saw, W.Pang, S.2014-09-022014-09-022012Biomass Conversion and Biorefinery, 2012; 2(4):327-3482190-68152190-6823http://hdl.handle.net/2440/84867Ammonia (NH3) is one of the main contaminants in the biomass gasification producer gas, which is undesirable in downstream applications, and thus must be removed. When the producer gas is used in integrated gasification combined cycle (IGCC) technology, NH3 is the main precursor of nitrogen oxides (NO x ) formed in gas turbine, whereas in Fischer–Tropsch synthesis and in integrated gasification fuel cell (IGFC) technology, the NH3 gas poisons the catalysts employed. This paper presents a critical review on the recent development in the understanding of the NH3 formation in biomass gasification process and in the NH3 gas cleaning technologies. The NH3 gas concentration in the producer gas can firstly be reduced by the primary measures taken in the gasification process by operation optimisation and using in-bed catalytic materials. Further removal of the NH3 gas can be implemented by the secondary measures introduced in the post-gasification gas-cleaning process. Focus is given on the catalytic gas cleaning in the secondary measures and its advantages are analysed including energy efficiency, impacts on environment and recyclability of the catalyst. Based on the review, the most effective cleaning process is proposed with integration of both the primary and the secondary measures for application in a biomass gasification process.en© Springer-Verlag 2012Ammonia removalBiomass gasificationGasification optimisationHot gas cleaningCatalytic reactorCatalystJournal article002013377410.1007/s13399-012-0047-12-s2.0-8497802520416873Saw, W. [0000-0002-2538-5811]