Visualisation of sulphur on single fibre level for pulping industry

作     者：Norlin, B. An, S. Granfeldt, T. Krapohl, D. Lai, B. Rahman, H. Zeeshana, F. Engstranda, P. 

作者机构：Mid Sweden Univ Holmgatan 10 SE-85170 Sundsvall Sweden Valmet AB Gustaf Gidlofs Vag 4 SE-85179 Sundsvall Sweden Argonne Natl Lab 9700 S Cass Ave Lemont IL 60439 USA Lund Univ MAX Lab 4 SE-22100 Lund Sweden 

出 版 物：《JOURNAL OF INSTRUMENTATION》 (J. Instrum.)

年 卷 期：2023年第18卷第1期

页      面：C01012-C01012页

核心收录：

学科分类：08[工学] 080401[工学-精密仪器及机械] 0804[工学-仪器科学与技术] 081102[工学-检测技术与自动化装置] 0811[工学-控制科学与工程] 

基　　金：Vinnova DOE Office of Science by Argonne National Laboratory [DE-AC02-06CH11357] 

主　　题：X-ray fluorescence (XRF) systems Instruments for environmental monitoring food control and medical use Data processing methods Image filtering 

摘      要：In the pulp and paper industry, about 5 Mt/y chemithermomechanical pulp (CTMP) are produced globally from softwood chips for production of carton board grades. For tailor making CTMP for this purpose, wood chips are impregnated with aqueous sodium sulphite for sulphonation of the wood lignin. When lignin is sulphonated, the defibration of wood into pulp becomes more selective, resulting in enhanced pulp properties. On a microscopic fibre scale, however, one could strongly assume that the sulphonation of the wood structure is very uneven due to its macroscale size of wood chips. If this is the case and the sulphonation could be done significantly more evenly, the CTMP process could be more efficient and produce pulp even better suited for carton boards. Therefore, the present study aimed to develop a technique based on X-ray fluorescence microscopy imaging (mu XRF) for quantifying the sulphur distribution on CTMP wood fibres. Firstly, the feasibility of mu XRF imaging for sulphur homogeneity measurements in wood fibres needs investigation. Therefore, clarification of which spatial and spectral resolution that allows visualization of sulphur impregnation into single wood fibres is needed. Measurements of single fibre imaging were carried out at the Argonne National Laboratory s Advanced Photon Source (APS) synchrotron facility. With a synchrotron beam using one micrometre scanning step, images of elemental mapping are acquired from CTMP samples diluted with non-sulphonated pulp under specified conditions. Since the measurements show significant differences between sulphonated and non-sulphonated fibres, and a significant peak concentration in the shell of the sulphonated fibres, the proposed technique is found to be feasible. The required spatial resolution of the mu XRF imaging for an on-site CTMP sulphur homogeneity measurement setup is about 15 mu m, and the homogeneity measured along the fibre shells is suggested to be used as the CTMP sulphonation measurement par