Concept of PPI energy technology complex upgrading

THE PURPOSE. Development and implementation of a set of theoretical and practical recommendations for creating scientifically founded heat flow diagrams for pulp and paper processes, intensifying heat exchanging processes under the economical use of energy resources. METHODS. The method of thermodynamic analysis on the basis of exergy increments in the process of interaction of heat flows is proposed, it allows evaluating the energy efficiency of both individual PPI units and the entire process flow; mathematical relationship between exergy efficiency of process elements and that of a complex heat flow diagram; schematic diagram of a heat recuperator of PBM drying section with a closed loop for the air delivered to drying. RESULTS. Thermodynamic analysis was made to evaluate energy efficiency of PPI equipment; the relationship between conversion factor of thermal pumping plant and thermodynamic properties of actuating media was obtained. Sulfate pulp production was considered in detail. The low energy efficiency of the existing process flow diagram is shown, with its exergy efficiency being equal to 48%. A main share of the consumed exergy (71% of the incoming one) relates to the recovery boiler processes. The process flow diagram consisting of hydrochemical pulpchips processing is suggested. The recovery boiler and rotary-type lime kiln are removed from that flow diagram. Risks of air and water basins pollution fall. The main ways for increasing energy efficiency of lignosulfonates production at sulfite pulp plants are mentioned. DISCUSSION. Further development of energy efficient pulp technologies can be forecasted on the basis of application of fluid technologies such as supercritical water oxidation (SCWO). The positive results of research in water chemistry under supercritical parameters give promise to predict success in developing the energy efficient pulp technology by exposing pulpchips to water at the subcritical and supercritical parameters. Paper and board production relates to the complex physical–chemical and heat-wet processes. The thermodynamic studies allowed determining low exergy efficiency of a drying section of paper and board machine that is because of inefficient operation of the heat recuperation unit. This circumstance is responsible for the bulk supply of low pressure steam from a heat and power plant. The main ways for improving the heat flow diagram of PBM drying section are shown. Cogeneration issues in the pulp and paper industry are considered. The essential attention is given to environmental safety of energy efficient technologies. CONCLUSION. The paper presents main ways for increasing energy efficiency of basic production processes at pulp and paper enterprises. Based on the analysis of exergy efficiency of individual equipment elements and the entire process flow diagrams bottlenecks were revealed and measures for their removal were suggested.

1. Lukanin PV. Energy saving problems at Russia’s pulp and paper enterprise. IV Scientific and technical conference «Forests of Russia: Politics, Industry, Science», Saint Petersburg, May 22-25, 2019: abstracts of reports. Saint Petersburg: POLITEKCH-PRESS. 2019; 304-306.

2. Lukanin PV. Assessment of energy efficiency of sulfate pulp production with the method of exergy increments. News of Higher Educational Institutions. Energy Problems. 2020; 2, 3-11.

3. Lukanin PV, Fiodorova OV., Pekaretz A.A., et al. Biofuel burning features and their interrelationship with relaxational-elastic properties of raw material and its chemical compositio. Problems of Mechanics of Pulp and Paper Materials: Proceedings of VI International scientific and technical conference in commemoration of Professor V.I. Komarov (Arkhangelsk, September 9-11, 2021) / Lomonosov Northern (Arctic) Federal University. Arkhangelsk: NARFU, 2021. 383-388.

4. Kazakov VG, Lukanin PV, Smirnova. A simplified method for determining the exergy efficiency of a complex thermal process flow diagram. Industrial Energy. 2010; 1, 38 - 41.

5. Lakhtikov YuO. Problems of Bioenergy Development at PPI Enterprises. Biofuel Congress, March 19-20, 2019, SPb.

6. Alekseev ES, Alent`ev AYu, AS. Belova, et al. Sverxkriticheskie flyuidy` v ximii. Uspexi ximii. 2020. T. 89. № 12. pp 1337-1427.

7. Hansen E, Panwar R, Vlosky R. The Global Forest Sector: Changes, Practices and Prospects. Taylor & Francis Group (NY); 2017.

8. Song AA filler distribution factor and its relationship with the critical properties of mineral-filled pape. BioResources. 2018. V.13. №3. P.6631-6641.

9. Kazakov VG, Lukanin PV, Smirnova OS. Heat technology in the lignosulfonates production. Industrial Energy. 2012; 7, 35-39.

10. Alen R, Sjöström E, Vaskikari P. Carbon dioxide precipitation of lignin from alkaline pulping liquors. Cellulose Chemistry and Technology. 1985;19(5):537-541.

11. Nimish D, Morrish K. CFD Analysis of Fluid Flowing Through a Heat Exchanger Tube Having a Twisted Tape with a Centrally Placed Semi-Circular Groove. International Journal of Science and Research. 2017;6(6):pp.2200-2207.

12. Spitzer DP, Chamberlain Q, Franz C., Lewellyn M., and Qi Dai, MAX HT TM sodalite scale inhibitor: plant experience and impact on the process, Light Metals 2008 (Edited by David H. De Young, The Minerals, Metals & Materials Society, 2008), 57-62.

13. Kazakov VG, Lukanin PV, Smirnova OS. Exergy analysis of sulfate pulp technology. Industrial Energy. 2011; 7, 37 - 42.

14. Patent № 2651412 the Russian Federation, MPK D21C 3/02 (2006.01). The Method for evaporation of liquors in pulp production: № 2017122502: decl. 26.06.2017: publ. 19.04.2018 / Lukanin PV, Kazakov VG, Fiodorova OV, Subbotina KO. declarant FSBEIHE SPbSUITD. 6pp.

15. Patent № 2670855 the Russian Federation, MPK D21C 3/02 (2006.01). The method of pulpchips cooking in pulp production: № 2017122501: decl. 26.06.2017: publ. 25.10.2018 / Lukanin PV, Kazakov VG, Fiodorova OV, Subbotina KO. declarant FSBEIHE SPbSUITD. 2p.

16. Kazakov V.G., Lukanin P.V., Smirnova O.S. Heat technology at the hydrochemical recovery of chemicals in sulfate pulp production. Industrial Energy. 2011; 7, 44-48.

17. Kazakov VG., Lukanin PV., Gromova EN. Vertical digester. Patent for useful model № 208723. 11.01.2022.

18. Kazakov VG., Lukanin PV, Gromova EN. Method for producing pulp. Patent for an invention № 2771348. 29.04.2022.