Treatment of Paper Product
Development of a Technological Process for Paper Product Treatment with a Neutralizing Reagent and Biocide
Tech Area / Field
- CHE-IND/Industrial Chemistry and Chemical Process Engineering/Chemistry
3 Approved without Funding
Russian Scientific Center of Applied Chemistry, Russia, St Petersburg
- Russian National Library, Russia, St Petersburg\nVNIIEF, Russia, N. Novgorod reg., Sarov
- Prezervation Academy GmbH, Germany, Leipzig\nInstituto Centrale per la Patologia del Libro, Italy, Rome
More and more amount of damaged and dilapidated documents is accumulated in the libraries of the whole world including Russia at present. Development of the efficient technology of mass treatment with a neutralizing agent of the large amount of documents without their preliminary untwisting is an actual problem relating to ensuring the long-term storage of library and archive stocks. Result of such a treatment includes the neutralization of existing paper acidity and creation of alkaline buffer reserve in it not less than 300 mg-equivalent/kg with prolonged effect, which retards the ageing and prevents paper destruction. Protection of the documents of persistent storage from biological damage connected with paper injure by microorganisms especially mould is also an important problem of ensuring their durability. Document treatment with biocidal preparations increases their bioresistance due to the suppression of bacterial flora: growth of the fungi of various species is inhibited or their development is suspended.
From among investigated and realizable in practice methods of mass neutralization of paper acidity of books and documents preference is given to gas-phase neutralization and method of nonaqueous neutralization with solutions or dispersions of neutralizing agents in organic solvents including the use of compressed gases.
The project proposes fundamentally new solution of the problem of neutralization of acidity of paper products: to carry out the process using CO2 on the contrary as their antisolvent. In proposed method the surplus of gaseous antisolvent (CO2) is added to neutralizing agent solution in organic solvent. Organic solvent and CO2 are mutually soluble, and neutralizing agent solubility in CO2 is restricted. Saturation of liquid phase with compressed CO2 leads to its volume expansion and decrease of its solution power relative to the neutralizing agent. On reaching the critical value of supersaturation, the neutralizing agent precipitates in the form of solid fine particles.
At present, the basic process flow diagram of paper acidity neutralization is developed in laboratory-scale plant of the RRC "PK" on the model samples of paper of various kinds using neutralizing agent solutions: chladone – methyl alcohol – magnesium methoxycarbonate and with CO2 as antisolvent. Alkaline reserve values up to
800 mg-equivalent/kg and paper pH values of 10.5 to 11.5 are obtained in the experiments. Results of the investigations of physicomechanical and optical indicators of treated paper samples after their artificial ageing equivalent to 75 years of natural ageing carried out by the NLR indicate the retention of main indicators of paper quality after the expiry of this storage time.
Investigation of the process of paper treatment with biocide began at the RRC "PK" in the same experimental laboratory-scale plant simultaneously with the development of paper acidity neutralization process. This work follows the numerous investigations of efficiency of the influence of biocides of various classes ensuring increase of the bioresistance of paper, sizing substances and case material on paper carried out at the NLR. Paper treatment with these compounds not only increases its bioresistance due to their fungicidal properties, but also improves a number of physicomechanical indicators of paper. Prolonged antimicrobial effect of these compounds is proved by the results of investigations of treated paper samples in extreme conditions (multihour exposure at the relative air humidity close to 100%), which confirmed retention of the biological resistance of paper. Solubility of biocides in alcohol and chladone, compatibility with neutralizing agent applied in the technology of paper acidity neutralization is an important factor of biocide choice. Fulfillment of these conditions will allow to carry out paper treatment with biocide together with paper acidity neutralization in the single technological process.
Purpose of the Project is development of the technology of mass book treatment of paper acidity neutralization with assurance of alkaline reserve not less than
300 mg-equivalent/kg, pH on the level of 10 and increase of its biological resistance.
Amount of the Work
Performance of the work on the Project will include the experimental and theoretical investigations of the processes of paper acidity neutralization and increase of its bioresistance using existing techniques and laboratory-scale plants with the subsequent creation of pilot setup for book treatment with a capacity up to 10 books per cycle and the appraisal of developed technology efficiency. Reference initial data for the designing of experimental-industrial setup for mass book treatment with a capacity not less than 100 books per cycle will be developed in the final stage of the work.
Available Scientific and Technical Backlog
Participants of the Project are the specialists in the field of experimental investigations of the process of paper product treatment, processes of mass exchange in multiphase systems, and in the field of development and testing of complicated gas-hydrodynamic benches to test materials. Available scientific and technical backlog of the participants of the Project comes in general to a few key theses:
- Experimental, technical, and theoretical knowledge in the problem of paper stabilization by its treatment with neutralizing agents in various technological media and water solutions of biocides are accumulated over the last years by the Organizations participating in the Project;
- Great experience of development and optimization of pre- and supercritical technology of paper acidity neutralization using carbon dioxide as a solvent of neutralizing agents is gathered;
- Experience of experimental and design-theoretical investigation of mass exchange processes in two-phase media on pre- and supercritical conditions of process carrying out is accumulated;
- Methods of the appraisal of paper treatment process efficiency, the calculation of relative paper durability and the techniques of determination of the solution composition of neutralizing agents, and main physicochemical, physicomechanical and optical characteristics of paper and its bioresistance are improved and approved;
- Experimental laboratory-scale plant to investigate the process of paper treatment with active stabilizing agents (neutralizing agents, biocides) is developed.
The proposed Project relates to category "Technology Development". The following scientific and technical results will be obtained during the Project execution:
- Processes of mixing of solutions in organic solvents (chladone – methanol – neutralizing agent – biocide) with carbon dioxide at precritical parameters will be investigated theoretically.
- Experimental and theoretical investigations of processes in mixing chamber and paper treatment reactor with determination of optimal ratios of the components of working solution and process parameters will be carried out.
- Experimental setup for the treatment of single paper sheets will be improved with the view of subsequent turn to book treatment.
- Process of regeneration of working solutions ensuring minimum loss of components will be developed.
- Technical and economical efficiency of technological process for the mass treatment of paper product will be estimated by the results of experimental development of the book treatment process in the experimental setup.
- Initial data for development of the experimental-industrial setup of mass book treatment (not less than 100 books per cycle) will be determined on the base of the results obtained in the Project.
- This development work will have a commercial potential as the prototype of experimental-industrial setup which can be used in many countries where it is required to preserve available book stocks, documents, manuscripts, archives, etc.
Conformity with the Goals of International Scientific and Technical Centre (ISTC).
- This Project completely answers the goals of ISTC:
- It is a new technological development work directed to the creation of high-performance technology of mass paper acidity neutralization and increase of its bioresistance answering the purposes of conservation of paper-based documents, a component of the national program of preservation of cultural and scientific heritage of the country;
- Results of the development of the Project can be used as the prototype of experimental-industrial setup for the mass treatment of paper-based documents in a number of countries where it is required to solve the problems of ensuring the preservation of library and archive stocks;
- It is a development work ensuring the alternative employment of highly skilled specialists of RFNC–ARRIEP (All-Russian Research Institute of Experimental Physics) and RRC "PK" earlier engaged to nuclear scientific and military programs and facilitating the attraction of research officers and engineers connected with the development of weapons of mass destruction in Russia to the activity of international scientific community;
- The Project gives to scientists and specialists of Russia connected with the development of weapons an opportunity to reorientate their efforts to peaceful activity;
- The Project is devoted to solving scientific and technical problems of the world level, therefore it promotes the integration of Russian scientists into international scientific community;
- Approaches, technical solutions, and scientific information obtained as a result of the Project execution can become an object of patenting and joint use of countries participating in the work financing;
- To fulfill the objectives posed in the Project it is proposed to use scientific and technical backlogs, setups and test benches, and developed diagnostic methods available at the RRC "PK", RFNC–ARRIEP, and the NLR. High skilled specialists earlier participating in the nuclear scientific and military programs will execute the work. Their experience in the carrying out of investigations will be widely used within the Project.
Potential Role of Foreign Collaborators
First, cooperation with foreign collaborators will allow to appraise critically the work progress within the Project. Second, it will enlarge the information scope of the participants of the Project. Third, it will expand the contacts of scientists and engineers with the world scientific community. All of that will allow to continue the long-term cooperation even after the Project completion.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.