The pulp- and paper production is a very energy intensive industry sector. Both Sweden and the U.S. are major pulpand paper producers. This report examines the energy and the CO2-emission connected with the pulp- and paper industry for the two countries from a lifecycle perspective. New technologies make it possible to increase the electricity production in the integrated pulp- and paper mill through black liquor gasification and a combined cycle (BLGCC). That way, the mill can produce excess electricity, which can be sold and replace electricity produced in power plants. In this process the by-products that are formed at the pulp-making process is used as fuel to produce electricity. In pulp- and paper mills today the technology for generating energy from the by-product in a Tomlinson boiler is not as efficient as it could be compared to the BLGCC technology. Scenarios have been designed to investigate the results from using the BLGCC technique using a life cycle analysis. Two scenarios are being represented by a 1994 mill in the U.S. and a 1994 mill in Sweden.The scenarios are based on the average energy intensity of pulp- and paper mills as operating in 1994 in the U.S. and Sweden respectively. The two other scenarios are constituted by a »reference mill« in the U.S. and Sweden using state-of-the-art technology. We investigate the impact of varying recycling rates and total energy use and CO2-emissions from the production of printing and writing paper. To economize with the wood and that way save trees, we can use the trees that are replaced by recycling in a biomass gasification combined cycle (BIGCC) to produce electricity in a power station. This produces extra electricity with a lower CO2 intensity than electricity generated by, for example, coal-fired power plants. The lifecycle analysis in this thesis also includes the use of waste treatment in the paper lifecycle. Both Sweden and the U.S. are countries that recycle paper. Still there is a lot of paper waste, this paper is a part of the countries municipal solid waste (MSW). A lot of the MSW is landfilled, but parts of it are incinerated to extract electricity. The thesis has designed special scenarios for the use of MSW in the lifecycle analysis. This report is studying and comparing two different countries and two different efficiencies on the BLGCC in four different scenarios. This gives a wide survey and points to essential parameters to specifically reflect on, when making assumptions in a lifecycle analysis. The report shows that there are three key parameters that have to be carefully considered when making a lifecycle analysis of wood in an energy and CO2-emission perspective in the pulp- and paper mill in the U.S. and in Sweden. First, there is the energy efficiency in the pulp- and paper mill, then the efficiency of the BLGCC and last the CO2 intensity of the electricity displaced by BIGCC or BLGCC generated electricity. It also show that with the current technology that we have today, it is possible to produce CO2 free paper with a waste paper amount up to 30%. The thesis discusses the system boundaries and the assumptions. Further and more detailed research, including amongst others the system boundaries and forestry, is recommended for more specific answers.