Application of Selected Methods of Life Cycle Assessment to Judgment of Environmental Hazard of Production Process of Flocculant Synthesized from Waste Phenol-formaldehyde Resin

This article describes the influence of the production process of a new type of flocculant obtained from the post-production waste of phenolformaldehyde resin on the quality of environment. Flocculants, used mainly in the processes of treatment of industrial and municipal wastewater, may also be employed in numerous industrial processes, such as thickening of suspensions in the processing of zinc and copper, carbon thickening and filtration, flocculation of ores after enrichment during the flotation process. Implementation of new technologies requires application of adequate methods for assessing the obtained ecological effects, which may contribute towards a higher ecological level of production. One of the methods which allows to determine the impact of a designed/implemented technology on the environment throughout the entire life cycle is the LCA - Life Cycle Assessment. The basis for the environmental research was the bench-scale technological research of the production process of amine derivatives of post-production waste of phenol-formaldehyde resin - SE novolac. The purpose of the analysis was to determine the environmental impact of the process of modification of post-production waste of SE novolac. In order to perform the LCA of the production of a potential flocculant, a production line was designed for the production of a new type of goods. The technological assumptions for the production of a new type of flocculant served as the basis for producing inventory tables on the basis of which a potential environmental impact of the product was determined, by application of the LCA, with the use of the SimaPro software, selecting three different methods of analysis: Eco-indicator 99, IMPACT 2002+, and ReCiPe. The functional unit was assumed to be 100 kg of amine derivative of SE novolac, as this was presumed to be the daily amount of production. Conducted with the application of the Eco-indicator 99, ReCiPe and Impact 2002+ methods, the LCA of the production process of amine derivative of SE novolac showed high variance in the results obtained, which is caused by different amounts of years for the normalization stage, as well as different weighing techniques in individual methods. This is why the ISO standards do not recommend announcing any results after the weighing stage. Such results may, however, be used in interpreting results of a sensitivity analysis, etc. High discrepancies in the final results suggest that the cause may well be the application of different characterization parameters for the same categories of influence in the applied methods. In all the methods applied, the factor influencing the environment is chiefly tin chloride. This is due to the fact that tin metal, hydrochloric acid, and electricity are used in its production. The environmental impact of hydrochloric acid is also considerable, as it is used in direct production of the discussed flocculant and of tin chloride. The analysis showed that the production of amine derivative of SE novolac involves high levels of reagents. Producing 1 Mg of flocculant requires the use of over 4 Mg of sulphuric acid, approx. 1.6 Mg of nitric acid, 4.8 Mg of hydrochloric acid, approx. 4 Mg of tin chloride, and 3 Mg of water. Their negative environmental impact is not reduced by using 1.5 Mg of post-production waste of phenol-formaldehyde resins. Variance in the results is also a proof of development and improvement of the LCA methodology.