CPPRI News Bulletin

» Research Activities

A. Plan Scheme Projects

1. Preservation of strength properties during pulping and bleaching

Under this project four mills Viz Sirpur paper Mills Ltd., Shreyans Paper Mills Ltd. , Trident Paper Mills and ITC Bhadrachalam were visited during the period. The pulp samples both unbleached and bleached were collected and analyzed for various parameter as viscosity, brightness. The lab scale pulping and bleaching studies of four paper mills raw material samples were carried out.

2.Studies on the Improvement of Paper Quality through Fractionation/Refining and Furnish Optimization

Fiber fractionation followed by selective processing of each fraction is now viewed to be an efficient means of producing papers of better quality in terms of strength, optical and printing properties. The studies on mill pulp containing mixed hardwood and bamboo furnish have been completed. Studies with waste paper grades of mixed office waste (MOW) and old corrugated container (OCC) are in progress. The different fractions were studied for deinking and papermaking potential.

The MOW pulp was separated into two fractions-long and short. Both fractions were deinked in laboratory deinking cell under same process conditions and hand sheets were examined for optical properties. The pulp from long fraction showed better results. Further work on OCC pulp is in progress.

3. Energy Conservation in Pulp & Paper Industry - Process Integration & Optimisation

The report submitted to one selected Pulp & Paper Mill based on Pinch analysis carried out in the mill has been appreciated by the mill. The mill has agreed in principle to implement the proposals highlighted in the report. A team of CPPRI scientists conducted exercise in another selected mill and collect data in the month of November 2003. CPPRI scientists also visited Indian Institute of Technology (IIT), Powai, Mumbai in connection with the development of pinch software as per the need of Indian Pulp & Paper Industry.

A team of CPPRI Scientists visited M/s Seshasayee Paper and Board Ltd., Erode (T. N.) another mill selected for studies from Nov. 4-6,2003 for collection of data and discussion with mill personal.

Based on data collected, detailed material & energy balances are being prepared for generating composite and grand composite curves.

4. Modification of Black Liquor Properties - Effect of System Closure

Paper buying standards as well as environmental and economic factors are increasing the interest in progressing towards low effluent closed cycle pulp & paper mills. For system closure to be realized, several problems need to be addressed. This includes chemical imbalance as well as build up of non-process elements in recovery cycle. This problem is more prominent in Indian Pulp and Paper Industry due to the type of raw material ( bamboo and annual plants) used.

Looking into this CPPRI has initiated work on this problem and mills were selected in the area of hard wood , bamboo and nonwood based raw-materials. Studies were conducted to identify the inputs & output level of non-process elements, thereby studying its build up in the system.

Experimental studies on Evaporative crystallization of ESP ash were carried out to reduce potassium and chlorides from chemical recovery loop with encouraging results. The study has revealed nearly 70% reduction in potassium and chloride content. Further studies are continued. Studies are also underway on selective separation of these NPE's by applying resins. Anthology on Impact of Non-process elements in chemical recovery and Black liquor characterization has been prepared. Institute has successfully conducted diagnostic studies on build up of non-process elements in chemical recovery system in a wood based mill and in one straw based mill.

5. Determination & Quantification of Odorous Emissions in Pulp & Paper Mills - Their Reduction/Elimination

The objective of this project is to determine and quantify different malodorous gases generated in pulp and paper mills and also to generate data based information on the level of various malodorous gases at different sulfidity and temperature as used by the industry. Various means to reduce or eliminate these malodorous pollutants will also be looked into.

Under this project three large-scale pulp & paper mills producing writing & printing papers and one producing newsprint were visited for the quantification and determination of NCG's. The sampling was done from various sources such as digester blow, digester relief, black liquor storage tank, evaporator vent, recovery boiler, smelt dissolving tank, lime kiln etc and samples were analysed for various NCG's using Gas Chromatograph and Gas tech detector tubes.

Laboratory studies were continued for the determination and quantification of malodorous gases (like hydrogen sulfide, methyl mercaptans etc.) generated during digester blow by carrying out cooking of different raw materials like bamboo and eucalyptus in laboratory digester at different sulfidity and temperature. The work is in progress.

6. Identification and Removal of contaminants for effective processing of Recycled Fiber:

QUANTIFICATION OF STICKIES-A prerequisite for stickies control programme

Measuring and controlling stickies in a recycled paper manufacturing process has always been a challenge. It requires an appropriate methodology to quantify the stickies concentr ation in recycled fibre stock. Stickies as the name indicates, owing to their permanent or temporary tackiness give rise to problems in paper manufacturing and results in product quality losses. The source of stickies may be Adhesives, inks, coatings, deinking chemicals, wet strength resins and other process additives which are introduced in the recycling system. As on today almost all the RCF based mills are facing the problem of sticky depositions, paper web breaks and poor product quality due to holes and spots which is mainly due to presence of sticky/ hotmelts contaminants present in the recycled fibre stock.

Keeping in view the above problems and in order to establish an appropriate methodology for quantification of stickies, CPPRI has procured Pulmac Master Screen which is designed to collect stickies and hot melt components on a filter paper which are retained on a slot screen having slot width of 0.1 mm (0.12mm/0.15mm slots are also available) termed as Macrostickies.

The macrostickies collected on filter paper is then press dried at 1350C and 68,900 Kpa for stickies and hot melts quantification, using Paprican Image Analyser.

A case study has been undertaken for a Newsprint mill having severe stickies problem. System audits have been conducted to evaluate the existing system for stickies removal efficiency, using Pulmac Master Screen for quantification.

Pulp samples collected from a nearby mill were evaluated for stickies counts across the process line from HD Pulper to couch pit decker as depicted in the graph below. The studies have clearly revealed that pH shocks and use of machine backwater increases the stickies count and the stickies area due to agglomeration.

CHART 1

POST BLEACHING OF RECYCLED PULP

Extensive laboratories studies were conducted on post-bleaching of deinked pulp obtained from a mill. Multistage bleaching sequences were tried to achieve target brightness of 80% ISO for initial pulp brightness of 66% ISO. Various sequences were tried with combination of oxidative/reductive bleaching sequence. Use of oxidative (H2O2) followed by FAS treatment resulted into 80% ISO pulp brightness with 98% Whiteness Index.

7. Demonstration of Color Reduction Technologies for Pulp & Paper Mill Effluent

ELECTRO-FLOCCULATION
Electro-flocculation studies have been conducted on bleached; unbleached washer filtrate and mechanical pulping effluent in continuous mode at the effluent flow rate of 10 lit/hr. Result of the findings is depicted in graph.

CHART 2

The fabrication of demo pilot plant of 1m3/hr capacity has been initiated to study the economic feasibility of the process.

PHOTO-OXIDATION

Laboratory studies have been initiated on UV irradiation of liquid effluent for color reduction using lab photo reactor. Preliminary studies conducted with combined bleach effluent have revealed that it is a second order reaction and using strong oxidant to catalyse the photons at 254nm wavelength, more than 98% color reduction efficiency can be achieved. The studies are continued to study the effect of various catalyst to promote the reaction rate. Color reduction efficiency of combined bleached effluent at different oxidant dosage with respected to time is depicted in the graph below

CHART 3

Further studies are focused on Combined Bleach Effluent and EP stage Effluent from a hardwood based mill. The studies encompasses optimization of process variables for UV irradiation technique to evaluate the process performance w. r. t. solids concentration, temperature, pH, retention time, light intensity etc.In the meanwhile CPPRI has also procured a laboratory ozonator to initiate the studies on ozonation as one of the promising technology for color reduction studies.

Enzymatic Deinking of Recycled Fibres

The objective of the project is development of the enzymatic deinking technology for recycled fibres using various enzyme combinations and adaptation of the technology in Indian Paper Industry. New cellulase producing strains were isolated and screened for higher cellulase production. Enzymatic deinking studies are continued with MOW varying pulping time and the retention time of the enzyme to get higher deinking efficiency.

Various single enzymes and enzyme combinations were evaluated on MOW. Enzyme combinations showed good results than single enzymes. Further studies are continued with the selected enzyme combination, varying enzyme doses and treatment time. Brightness and dirt count levels of enzyme treated and untreated pulps are evaluated along the process line. Various enzyme combinations with surfactants are studied on different grades of waste paper. Studies on characterisation of deinking sludge are initiated.

B. Cess Funded Projects

Preparation of Monograph of Different Non Wood Raw Materials

Under this project photographic of different raw material's fiber are carried out and included in the final report, which is under preparation.

Energy Performance Evaluation and Optimization in Pulp and Paper Industry

The Energy Audit studies were conducted in following large Pulp and Paper mills:

¤ M/s Ballarpur Industries Ltd., Yamunanagar, Haryana.
¤ M/s The Sirpur Paper Mills Ltd., Sirpur- Kaghaznagar (A.P.)

So far 14 mills have been covered under project activities. Data collected during the energy audit have been analyzed and based on it a report containing respective energy conservation proposals has been prepared and submitted to M/s Ballarpur Industries Ltd., Yamunanagar. The report on energy audit has been prepared and submit to the mill . M/s Shesasayee Pulp & Paper Boards Ltd., Erode (T. N.) was also visited by CPPRI scientists to evaluate the performance of selected pumps. Final report on the audits carried out under the project is in progress.

Calibration and Intra Laboratory Quality Assessment Service for Pulp and Paper and Allied Industries (CESS/IPMA sponsored)

The paper reels of different type of papers were received from two mills. Comparative test samples were prepared from the reels and sent to seven mills for the evaluation of properties like smoothness, thickness, brightness, tensile strength and double fold using their instruments. The results received were evaluated statistically. The comments regarding the performance were sent to mills. Work is in progress.

Studies on Benchmarking/Input Norms in Pulp & Paper Industry

Subsequent to the collection of data and information from various Pulp & Paper Mills, the data is being analyzed by using statistical methods to arrive at appropriate norms for different sectors of the industry. The final report is being prepared.

Demonstration of Enzymatic Prebleaching in a Pulp & Paper Mill

The Institute is going to demonstrate the enzymatic prebleaching technology on mill scale in Seshasayee Paper & Boards Ltd., Erode. Scientists of CPPRI visited SPB to discuss the existing facilities and also the necessary facilities for enzymatic prebleaching technology. Procurement of MC pump , Motor and final selection of enzyme supplier are under process. The short listed enzymes are evaluated using the process conditions of SPB.

Detoxification of Bleach Plant Effluent for Recycling & Reuse

The results & outputs of the project were presented before the participants during the Workshop on Frontier Technologies Addressed under Cess Funded Projects organized by CPPRI at Scope Complex, New Delhi in May 2003. Based on the recommendations/ suggestions made by the participants as well as during the project review meetings the project activities have been extended upto March 2004 in the following areas so that the outputs of the project can be more useful to the industry:

¤ Toxicity studies of untreated and treated bleach plant effluent
¤ Characterisation & disposal of sludge generated during electrofloculation and chemical treatment
¤ Explore the options for recycling / reuse of bleach plant effluents within the process.

The project is nearing completion. Most of the activities of the work plan have been completed as per work plan. Studies on toxicity of treated and untreated bleach plant effluents, characterization and disposal of sludge generated during Electrofloculation and chemical treatment were continued. Meanwhile compilation of data & report preparation is also being carried out simultaneously.

C. Cess Funded Projects

Biotechnological Application of Enzymes for Making Paper, Pulp from Green Jute and Kenaf (UNDP Sponsored Project)

Under this project large-scale jute kraft pulp was treated with two commercial Enzymes followed by CEpH bleaching.

Procurement of Jute Samples

The Jute Samples for Pilot Plant scale trial has been procured. For this, two of CPPRI Scientist visited Calcutta for on sight harvesting, collection and transportation arrangement of green jute to bring it CPPRI.

CPPRI has successfully completed two pilot pulping trials using kraft process on whole jute pulping under the UNIDO - IJSG project "Biotechnological application of enzyme for making paper pulp from green jute/ Kenaf." The project activities are under progress.

In this connection Input data from representative mills from different categories such as forest based, agro based, waste paper based, newsprint and rayon grade based has already been collected and it is now being analysed after updation / correction from the mills to get best results of the study.

Process Audit Studies of HPC Cachar Unit

Project on process audit studies is sponsored by HPC Cachar unit. Studies of various plant parameters for pulping and bleaching are on progress.

Pulping and bleaching optimization of debarked eucalyptus. (Sponsored by JK Paper Mills Ltd, Orisa)

Studies on pulping and bleaching optimization of debarked eucalyptus were conducted and after completion report was sent to sponsorer

Revision of Comprehensive Industry Documents (COINDS) for Small & Large Scale Pulp & Paper Industries (CPCB Sponsored Project)

CPPRI has been assigned the task to revise the comprehensive industry documents (COINDS) for small and large scale pulp & paper mills prepared by CPCB in early 1990's. The main objective of the task is to review and revise the environmental discharge norms including potential of cleaner production options in Indian pulp & paper industry.

In continuation of earlier studies, the team of scientists visited JK Paper Mills, Rayagada (Orissa), Andhra Pradesh Paper Mills Rajahmundry (A P), M/s Mysore Paper Mills, M/s Harihar Polyfiber , M/s ITC -Speciality Paper & Boards Ltd, & M/s Delta Paper Mill Ltd) for collection of data related to process operations as well as collection of effluent and solid waste samples and air monitoring. The samples collected are being analysed for various pollutional parameters and compilation of data.

4. Life Cycle Assessment Study in Pulp & Paper Mills in India (IARPMA sponsored Project)
The main objective of the project is to increase the productivity in the paper sector and improve the environment as a whole by identification of gaps between the existing operating conditions and the international benchmarks. LCA study will be helpful to the industry in sustainable development and provide opportunities to increase process efficiency and thus make them able to compete in global market.

A joint review meeting of MoEF, CPCB, IARPMA & CPPRI officials was held at CPPRI to discuss the project outputs. It was also discussed that since data collected / samples analysed during the single visit to the mills may not be representative data and also some mills have already undergone expansion. As such it was suggested to undertake one more visit to the selected mills in order to generate more realistic data . In this perspective the project activities was extended for further six months and during which a final visit to each of the following five selected mills will be undertaken to have a more comprehensive data.

In the same reference a second visit was undertaken to Star Paper Mills, TNPL & Tehri Pulp & Paper Mills for collection and analysis of effluent & solid waste samples & air monitoring.

The samples of effluent & solid waste collected during the second visit to M/s TNPL , Star Paper MiIls & Tehri Pulp & Paper Mills Ltd were analysed for various pollutional parameters . Second visit to M/s Madhya Bharat Papers Ltd, Chapa, M.P. & M/s Kalpatru Papers Ltd, Ahemdabad ,Gujarat are being planned in January 2004.

Effects of second stage extraction stage on pulp quality in CEpHHED bleach sequence of bamboo pulp (HPC Sponsored Project)

To justify the any losses due to removing second stage extraction stage, HPC sponsored this project. The project report after completion has been sent to sponsor.

Oxygen treatment study of star paper mill pulp and its impact on bleaching of pulp (Star Paper Mills Ltd. Sponsored Project)

Studies were conducted on various condition to check the feasibility of oxygen treatment on SPM pulp. Project was completed and finally has been sent to the sponsorer.