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Evaluation of soap recovery efficiency from black liquor — analytical tools, TAPPI Journal April 2023

ABSTRACT: Soap skimmings (“soap”) are typically recovered from black liquor in kraft mills that process a high percentage of softwood. In many mills, the recovery of soap is inefficient, negatively impacting performance of evaporators and recovery boilers and resulting in loss of potential revenue. A thorough evaluation of soap recovery performance in a kraft mill requires measurement of soap content in black liquor at various sampling locations, especially around the soap skimmer.The standard laboratory method for evaluating soap content in black liquor is a complex, multi-step process that relies on solvent extraction and titration; most mills send these samples to an outside laboratory for this analysis. In this study, 100 black liquor samples, with a wide range of soap concentrations, were tested by the standard solvent extraction method. After additional dilution, each sample was also tested for surface tension with a bubble pressure tensiometer. The results were found to correlate very closely with the solvent extraction tests results. This alternate method, using surface tension measurements of diluted black liquor samples, produces rapid results and can be easily implemented in most kraft mills, which would facilitate much more frequent in-house evaluations of soap recovery performance.

Comparative study of guar gum and its cationic derivatives as pre-flocculating polymers for PCC fillers in papermaking applications, TAPPI Journal April 2022

ABSTRACT: In this work, gums from guar seeds were evaluated as a potential precipitated calcium carbonate (PCC) filler pre-flocculant to induce functional filler in papermaking applications. In recent years, guar has been conidered one of the promising wet-end additives due to its abundance, rich source of hemicellulose content, and bio-degradability. However, application of guar gum in filler pretreatment methods for producing high ash paper has scarcely been reported. In this paper, the flocculating ability of three types of guar gum was established with charge analysis and turbidity (NTU) of the system at 1% and 5% for each gum: native gum (NG) having a degree of substitution (DS) of 0, and cationic gums having a DS value of 0.07 (CL) and 0.15 (CH). It was interesting to observe that even at a 5% dose of G, the charge density of PCC did not deviate much from the initial values. The system carried a weak negativeharge, resulting in an unstable colloidal suspension that led to PCC-PCC particle bridging. On the other hand, the operative mechanism of CL and CH during adsorption and PCC flocculation was predicted to be charge neutralization and electrostatic-patch formation, accompanied by particle bridging. Note that CL, with a maximum 47.5% eduction in residual turbidity of PCC at a 1% dose, was much more efficient in doing so than the other two gums; NG had a 40% maximum reduction in residual turbidity at a 5% dose and CH had a maximum 30% reduction at a 1% ose. Later on, floc formation and structure were correlated with optical and field emission scanning electron microscopy (FE-SEM) images. In the next set of trials, paper properties were determined by varying the different gum dosages from 0.2% to 5% at a constant dose of 20% filler. It is also noteworthy to mention that with 1% CL (low DS) dose, PCC retention increased by 39%, which also enhanced the tensile, tear, burst, and opacity properties by 11%, 19%, 5%, and 4.4%, respectively, without significantly affecting the bulk properties. Further, wide-angle X-ray diffraction (XRD) analysis nd Fourier transform infrared (FTIR) analysis revealed that pre-flocculating PCC with a 1% gum dose did not induce any change in crystalline transformation. Based on observation, it was found that cationic gums with low DS values re a better choice for maximizing the strength of paper while maintaining bulk and high opacity when pre-flocculaion is adopted to increase the filler retention in paper.

The Effect of Dissolved Organics Substances on the Distribution of Metal Ions in a Pulp Suspension, 2004 Engineering, Pulping, and PCE&I Conference

The Effect of Dissolved Organics Substances on the Distribution of Metal Ions in a Pulp Suspension, 2004 Engineering, Pulping, and PCE&I Conference

Ultrasonic Systems for Liquid Absorption Measurement: Ultrasonic Systems for Liquid Absorption Measurement, 2005 Papermakers Conference

Ultrasonic Systems for Liquid Absorption Measurement: Ultrasonic Systems for Liquid Absorption Measurement, 2005 Papermakers Conference

On-Site Production of a Silica Based Microparticulate Retention and Drainage Aid, 1994 Papermakers Conference Proceedings

On-Site Production of a Silica Based Microparticulate Retention and Drainage Aid, 1994 Papermakers Conference Proceedings

Tissue fabric cleaning and conditioning.pdf

Jessica Spadaccino

TAPPI member Jessica “Jessi” Spadaccino has a quest to continue learning and growing – both her connections and career.

Machine Vision: Putting the Quality into the Product, 1993 F

Machine Vision: Putting the Quality into the Product, 1993 Finishing and Converting Conference Proceedings

Latex Modification of Urea Formaldehyde Resins: A Review and New Approaches, 1997 Nonwovens Conference Proceedings

Latex Modification of Urea Formaldehyde Resins: A Review and New Approaches, 1997 Nonwovens Conference Proceedings

TAPPI_Press_Catalog_2024_Web.pdf