In the paper energy crops of considerable cultivation potential in Poland, namely: Salix viminalis, Helianthus tuberosus, Sida hermaphrodita, Spartina pectinata, Andropogon gerardi and Miscanthus X giganteus were tested in terms of steam gasification reactivity of biomass chars, as well as yields and composition of product gas in steam gasification and lime-enhanced steam gasification in a laboratory scale fixed bed reactor at 650 degrees, 700 degrees and 800 degrees C. The highest value of reactivity for 50% of carbon conversion, R(50), was observed for Sida hermaphrodita, regardless the process temperature. Application of CaO for in-situ CO(2) capture in steam gasification of biomass chars resulted in hydrogen content increase at 650 degrees C to the levels comparable with the ones reached at 800 degrees C without carbonation reaction. Also hydrogen and total gas yields increased in tests of lime-enhanced gasification. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.