Inventory audit notice: TAPPI Press orders will not be processed from August 21–28 during our fiscal year-end inventory audit. Orders placed during this time will ship starting August 31, in the order received. Normal payment processing also resumes August 31.

Thanks for your patience — this helps us serve our members better.

Search

Use the search bar or filters below to find any TAPPI product or publication.

Showing 4,491–4,500 of 5,025 results (Duration : 0.019 seconds)

Filters

Industry

Topics

Content Type

Publications

Level of Knowledge

Committees

Collections

Journal articles
Open Access
Prediction of residual calcium carbonate (CaCO3) in the lime

ABSTRACT: In a kraft pulp mill, the rotary lime kiln is responsible for converting calcium carbonate (CaCO3) into calcium oxide (CaO) to be reused in the causticizing plant. An important parameter of the calcination efficiency and the product quality is the amount of CaCO3 not converted to CaO, commonly defined as residual carbonate. This parameter is usually determined through laboratory analysis, which introduces delays in process control and limits the ability to make timely operational adjustments. This work presents a predictive model that functions as a soft sensor for the residual carbonate in a lime kiln of a Brazilian kraft pulp mill. This model was able to estimate residual CaCO3 every 30 min using routinely measured online process variables, which is a considerable reduction from the 6-h average laboratory measurement. The correlation coefficient (r) between the model predictions and the mill values was 0.83, with a mean absolute error (MAE) of 0.33%. Considering the effect of the residence time throughout the lime kiln proved to be decisive in obtaining a satisfactory prediction result. After model validation, a variable importance analysis showed that the carbon monoxide (CO) concentration in the stack flue gas (in ppm), secondary air temperature (in oC), and fan speed (in %) were the most influential variables in predicting the residual carbonate content. Combined with commonly used operation expertise, this subset of variables can serve as additional information to achieve smoother lime kiln operation.

Journal articles
Open Access
Effect of the pressure difference over the screen basket on the performance of a pressure screen, TAPPI JOURNAL, April 1999, Vol. 82(4)

Effect of the pressure difference over the screen basket on the performance of a pressure screen, TAPPI JOURNAL, April 1999, Vol. 82(4)

Journal articles
Open Access
Effects of system closure on retention- and drainage-aid performance in tmp newsprint manufacture, TAPPI JOURNAL, April 1999, Vol. 82(4)

Effects of system closure on retention- and drainage-aid performance in tmp newsprint manufacture, TAPPI JOURNAL, April 1999, Vol. 82(4)

Journal articles
Open Access
Through-air drying of tissue and towel grades, TAPPI JOURNAL, April 1999, Vol. 82(4)

Through-air drying of tissue and towel grades, TAPPI JOURNAL, April 1999, Vol. 82(4)

Journal articles
Open Access
Shop talk: improving dryer performance: converting to stationary siphons with turbulence bars, TAPPI JOURNAL, April 1999, Vol. 82(4)

Shop talk: improving dryer performance: converting to stationary siphons with turbulence bars, TAPPI JOURNAL, April 1999, Vol. 82(4)

Journal articles
Open Access
Aquasol: a new process to deink old newsprint, TAPPI JOURNAL, August 1999, Vol. 82(8)

Aquasol: a new process to deink old newsprint, TAPPI JOURNAL, August 1999, Vol. 82(8)

Journal articles
Open Access
Retention of precipitated calcium carbonate in old corrugated container furnishes, TAPPI JOURNAL, August 1999, Vol. 82(8)

Retention of precipitated calcium carbonate in old corrugated container furnishes, TAPPI JOURNAL, August 1999, Vol. 82(8)

Journal articles
Open Access
The inhibition of migration of contaminants from paper into packaged foods, TAPPI JOURNAL, August 1999, Vol. 82(8)

The inhibition of migration of contaminants from paper into packaged foods, TAPPI JOURNAL, August 1999, Vol. 82(8)

Journal articles
Open Access
Relationship between phenol-formaldehyde resin chemistry and paper saturation, TAPPI JOURNAL, August 1999, Vol. 82(8)

Relationship between phenol-formaldehyde resin chemistry and paper saturation, TAPPI JOURNAL, August 1999, Vol. 82(8)

Journal articles
Open Access
Biofiltration to reduce voc and hap emissions in the board industry, TAPPI JOURNAL, August 1999, Vol. 82(8)

Biofiltration to reduce voc and hap emissions in the board industry, TAPPI JOURNAL, August 1999, Vol. 82(8)

Inside this Section