Cleaner Production Measures in Pulp and Paper Processing

2010 ◽  
pp. 110-263
Keyword(s):  
Pulp And Paper ◽  
Cleaner Production

Cleaner Production Technology on Controlling Emissions of Unintentionally Produced PCDD/Fs from Non-Wood Pulp and Paper Mills in China

2011 ◽  
Vol 236-238 ◽  
pp. 1120-1123
Author(s):  
Guo Yu Sun ◽  
Wei Li
Keyword(s):  
Paper Industry ◽  
Wood Fiber ◽  
Wood Pulp ◽  
Pulp And Paper ◽  
Cleaner Production ◽  
Raw Material ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Bleaching Process ◽  
Elemental Chlorine

As one of the main emission sources of PCDD/Fs, the pulp and paper industry has always been public concerns. In China, the consumption of non-wood fiber as raw material of pulp accounts for a relatively larger proportion in the total productivity. Here, the unintentionally produced PCDD/Fs emissions of five Chinese non-wood pulp and paper mills were investigated. The results showed that the increment of PCDD/Fs after bleaching with chlorine was about 1.71-28.19 times in pulp and 3.96-28.82 times in wastewater based on the existing technologies. In order to reduce the unintentional production of PCDD/Fs, the BAT/BEP transformation program was proposed as cleaner production initiatives featured by less or free use of chlorine in bleaching process, and evaluated by reduction effects and costs. The study showed the application of Elemental Chlorine Free (ECF) sequences in bleaching process with improving technologies in other production stages would effectively decrease the generation of PCDD/Fs, other pollutant load as well as the water consumptions.

Co-cooking nonwoods with hardwoods

TAPPI Journal ◽  
2014 ◽  
Vol 13 (6) ◽  
pp. 19-24
Author(s):  
TROY RUNGE ◽  
CHUNHUI ZHANG
Keyword(s):  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Strength Properties ◽  
Agricultural Residues ◽  
Kraft Pulping ◽  
Pulp And Paper ◽  
Strength Increase ◽  
Xylan Content

Agricultural residues and energy crops are promising resources that can be utilized in the pulp and paper industry. This study examines the potential of co-cooking nonwood materials with hardwoods as means to incorporate nonwood material into a paper furnish. Specifically, miscanthus, switchgrass, and corn stover were substituted for poplar hardwood chips in the amounts of 10 wt %, 20 wt %, and 30 wt %, and the blends were subjected to kraft pulping experiments. The pulps were then bleached with an OD(EP)D sequence and then refined and formed into handsheets to characterize their physical properties. Surprisingly, all three co-cooked pulps showed improved strength properties (up to 35%). Sugar measurement of the pulps by high-performance liquid chromatography suggested that the strength increase correlated with enriched xylan content.

Development of a Jacobian Module for Advanced Pulp and Paper Simulation and Control

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 4-11
Author(s):  
MOHAMED CHBEL ◽  
LUC LAPERRIÈRE
Keyword(s):  
Control System ◽  
Nonlinear Behavior ◽  
Simulation Software ◽  
Pulp And Paper ◽  
Pid Controllers ◽  
Tuning Parameters ◽  
Pid Tuning ◽  
Fixed Set ◽  
And Control ◽  
Operating Points

Pulp and paper processes frequently present nonlinear behavior, which means that process dynam-ics change with the operating points. These nonlinearities can challenge process control. PID controllers are the most popular controllers because they are simple and robust. However, a fixed set of PID tuning parameters is gen-erally not sufficient to optimize control of the process. Problems related to nonlinearities such as sluggish or oscilla-tory response can arise in different operating regions. Gain scheduling is a potential solution. In processes with mul-tiple control objectives, the control strategy must further evaluate loop interactions to decide on the pairing of manipulated and controlled variables that minimize the effect of such interactions and hence, optimize controller’s performance and stability. Using the CADSIM Plus™ commercial simulation software, we developed a Jacobian sim-ulation module that enables automatic bumps on the manipulated variables to calculate process gains at different operating points. These gains can be used in controller tuning. The module also enables the control system designer to evaluate loop interactions in a multivariable control system by calculating the Relative Gain Array (RGA) matrix, of which the Jacobian is an essential part.

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