Integration of biomass energy technologies with carbon capture and sequestration could yield useful energy products and negative net atmospheric carbon emissions. We survey the methods of integrating biomass technologies with carbon dioxide capture, and model an IGCC electric power system in detail. Our engineering process model, based on analysis and operational results of the Battelle/Future Energy Resources Corporation gasifier technology, integrates gasification, syngas conditioning, and carbon capture with a combined cycle gas turbine to generate electricity with negative net carbon emissions. Our baseline system has a net generation of 123 MWe, 28% thermal efficiency, 44% carbon capture efficiency, and specific capital cost of 1,730 $ kW(e)(-1). Economic analysis suggests this technology could be roughly cost competitive with more conventional methods of achieving deep reductions in CO2 emissions from electric power. The potential to generate negative emissions could provide cost-effective emissions offsets for sources where direct mitigation is expected to be difficult, and will be increasingly important as mitigation targets become more stringent. (c) 2005 Elsevier Ltd. All rights reserved.