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6 Uppsatser om Knots - Sida 1 av 1
Produktion av Pyrolysolja från kvistrejekt
Fast pyrolysis is a method for converting biomass into three energy rich products: char, gas and bio-oil, where the latter is most interesting. Pyrolysis is an endothermic process where biomass is heated in an anaerobic environment and, with the right operating conditions, up to 80 %wt bio-oil can be extracted. Key parameters for fast pyrolysis are: stable reactor temperature (~500°C), short residue time for gas in the reactor (<2 s) and a very high heating rate for the biomass. Today there are several different process solutions for fast pyrolysis, where fluidized beds and rotating cones are most developed. Bio-oil has compared to fossil oil: lower heating value, low pH and also polymerizes with time. Because of this upgrading is desirable for increasing competitiveness.
Visuell handelsortering av furu och gran
This essay concerns the visual trade grading of pine and spruce.In the 1800s developed rules for sorting of wood. The rules used to facilitate the export trade.The terms of the regulatory sorting systems developed in the 1900s. While it still used some of the older terms.The essay deals with how the grading rules affect the use of wood and how the rule work and how the terminology works.Some of the terms used for sorting are O/S, Kvinta, Utskott and A,B,C,D.You sorting by counting the numbers of Knots, cracks and other characteristics of each piece of wood.The sawmills have much influence in how the rules developed.Today it is often already determined in the sawmills which uses each piece of wood most have..
Tillväxt och potentiell sågtimmerkvalitet i gallringsmogna jämförelseplanteringar med Pinus contorta och P. sylvestris :
The Swedish Cellulosa Companiy, SCA, has today 280 000 ha planted with lodgepole pine (Pinus contorta var. latifolia) (?C?) which is equivalent to 14 % of its total forest area. Exotic lodgepole pine has in previous experimental stands shown a superior growth than the native Scots pine (Pinus sylvestris L.) (?S?).But also the comparison could be questioned because stand histories were was unknown and also differences in age between C and S existed.
Kvistreaktioner vid förhöjd torktemperatur
I föreliggande arbete har mätningar och utvärderingar av kvistreaktioner utförts. Mätningar av kvistkrypning har utförts på furubräder och mätningar av kvistsprickor i högtemperaturtorkad gran. En fältstudie innehållande en nulägesanalys och probleminventering följdes av ett antal provtorkningar. Torkningsförloppen filmades med en videokamera för att detektera när under torkningen som kvistarna kröp. Torkningsscheman togs fram med hjälp av ett torkningssimuleringsprogram samt med hjälp av erfarenheter från industrin.
Sawn softwood in Egypt ? a market study
This market study was written on behalf of Uni4 Marketing (U4M) and investigates the Egyptian softwood market. The objective was to identify what characterises a good softwood supplier according to Egyptian importers. In addition to this U4M?s competitiveness compared to their competitors was evaluated. The study also identified possible sources of competitive advantage possessed by U4M.
Picea mariana ((P. Mill.) B.P.S), P. abies (L.), Pinus contorta (Dougl.) och P. sylvestris (L.) : en jämförelse av produktion och potentiell kvalitet hos försöksbestånd i Jämtlands län
Swedish forests are dominated by just two conifer species Norway spruce and Scotch pine. They are not able to achieve the highest possible production or fulfill industry demands for raw materials. The introduction of exotic conifers can potentially meet these shortcomings and present a relevant solution.
This study was conducted in a block experiment with ten blocks planted in 1987 by SCA in North Sweden. The objective of the block experiment was to study if Black spruce is an appropriate alternative to Lodgepole pine, Norway spruce and Scotch pine on different site classes.