Identification The Bio-based Materials By Liquid Scintillation Counting

With the concept of sustainable development and environmental protection consciousness strengthening,people are focused on the development and utilization of renewable resources,especially the research and development of bio-based materials.To determining the bio-based content of materials,American Society of Testing Materials drawn up the ASTM D6866 standard,and Comite Europeen de Normalization has enacted CEN/TS 15440:2006.While,the research of determining the bio-based content of materials is relatively slow in China,and there is no one relevant standard set up now.In this thesis,we took the methods of synthetic benzene and CO₂ absorption for sample preparation and build the devices,then chose coal as background material and sugar carbon as reference material to establish an identification method between wood-based and coal-based activated carbon,bio-based foam and petroleum based foam with liquid scintillation counting.The main research contents and results summarized as follows:1.The construction of the device.Design experiment plan to build the benzene synthesis device,the solid materials can be converted to liquid benzene,and determined of 14 C activity level by liquid scintillation counters.The device has mainly two parts,the combustion system and benzene synthesis system.The combustion system is mainly to research the process conditions of CO₂ purification and collection,and the benzene synthesis system is mainly about the process conditions research of C2H2 purification and benzene synthesis.2.The establishment of identification between wood-based and coal-based activated carbon.Took the method of synthetic benzene for sample preparation with chose coal as background material and sugar carbon as reference material,the method of synthetic benzene was not the same with ASTM D6866 Method C.Firstly,the 14 C activity level of background material and s reference material were defined 0.408 DPM/g and 16.630 DPM/g,and then established a measurement system of determining the biomass content.Identify thewood-based and coal-based activated carbon by the comparing with the different results of 14 C activity level.The determination values compared with the theoretical values to confirm the specific ratio of wood-based and coal-based activated carbon.This research displayed that the relative errors of determination values and theoretical values are between 2.85% and 4.16%,which is consist with the acceptable tolerance levels of 5 % in ASTM D6866 Method C.3.The identification of bio-based foam and petroleum based foam.Samples quantity and process conditions were defined by element analysis and thermogravimetric analysis.In this paper,identification system between the unknown sources of bio-based foam and petroleum based foam is set up.The biomass content of sample 3 is 5.32% in this lab,and 5.1% coming from Chinese Academy of Inspection and Quarantine with same method and different lab,the relative error was 2.11%,which was less than 5% in ASTM D6866 Method C;the biomass content of sample 3 and sample 4 are 5% and 11% in Beta Analytic Inc.USA with different method and different lab,the corresponding results are 5.32% and 10.95% in research lab.Data analysis shows that the results of our laboratory measurement are accurate and reliable.4.Sample preparation of identification of bio-based material by CO₂ absorption method.Because of complicated benzene synthesis process conditions and time consuming,CO₂ absorption method was taken for operation easier and sample preparation and determination more quickly.Firstly,this paper explored the process conditions of CO₂ absorption method with ethanolamine absorbent and Hionic-Fluor cocktail.CaCO₃ could be manufactured according to the combustion system of benzene synthesis method,then CO₂ absorption solution preparation.When the ethanolamine was 15 mL,the CaCO₃ mass must be less than about 11.54 g,so that it could prevent the absorption equipment to burst and complete the effective absorption of CO₂.However,the determination results were not satisfactory,this thesis had no systematic analysis and research as the huge workload and time limit,which need continue to explore in the future or other scientific research workers continue to research.