Investigation of Greenhouse Gas Reduction Possibilities for TetraPak Inventing AB, Fjällbacka
Examensarbete för masterexamen
TetraPak AB aims to reduce direct and indirect CO2-emissions from their production sites by 10% in 2010 compared to the year 2005. This project investigates the possibilities of reducing GHG (greenhouse gas emissions) from TetraPak Inventing AB, Fjällbacka. Currently, the factory only uses fossil feedstocks and fuels. The main GHG emission sources in the production unit is a CatOx (catalytic oxidizer) used as VOC abatement technology for destroying the vaporized solvents (MEK) and two oil boilers used for space heating on cold days. Indirect emissions come from electricity consumption from the grid, raw material extraction and processing and transportation of products and feedstocks. TetraPak, Fjällbacka plans a capacity increment in 2010 in which the amount of solvents will double. This study focuses only on possible process modifications at the production site and possible changes to the electricity supply system. The following GHG emission reduction possibilities are investigated: switching the fossil fuels to renewable fuels, introduction of sustainable electricity production technologies, increasing the overall efficiency of the plant, reducing the consumption and recycling solvents. The calculations were carried out for two different electricity supply systems; grid electricity and wind power. For reducing the direct emissions two new VOC abatement technologies were investigated; destruction of VOCs in a micro gas turbine cycle and recovering the MEK in a condenser. In addition modifications for improving the efficiency of the existing CatOx, as well as retrofitting the oil boilers for wood pellet operation were investigated. Both VOC destruction technologies produce more heat than is needed for space heating purposes. Selling the excess waste heat is not an option since neither district heating network nor other industrial plants exist in the area where the factory is located. The possibility to use waste process heat so as to be able to switch from electricity driven compression chillers to heat driven absorption chillers was also investigated. The environmental and economical performance of VOC and cooling production systems in the two electricity supply systems was investigated as a last step. Within the system boundaries of this project, it was found that the emission reduction potential is almost 100%. The results also show that CatOx is not an efficient way of handling the VOC stream. Instead the solvent should be recycled back to the system both from an economical and environmental point of view. Due to the high electricity demand and the revenue gained by green electricity certificates installing a wind turbine for on-site power production should be a profitable option for the company.
Kemisk energiteknik , Chemical energy engineering