Thailand has been the world’s largest natural rubber (NR) producer since 2003. Concentrated latex is one of the three primary rubber products (the other two are block rubber and ribbed smoked sheet rubber), used as raw material for dipped rubber products such as gloves, condoms. Since NR products are being exported to the international market, they need a declaration of information on sustainable production in the near future. The production of concentrated latex is an energy-intensive process, and contributes to several environmental pollutions. Several studies exist on the treatment of this pollution, especially on wastewater treatment for concentrated latex mills. However, studies including a life cycle assessment or cleaner technologies for this industry are still limited.
The objective of this study is to assess the potential environmental impact of concentrated latex production by Life Cycle Assessment (LCA), and to investigate the effects of cleaner technology (CT) options to reduce the impact.
The methodology is based on the ISO 14040 series, taking a “Gate-to-Gate” approach (Partial LCA). Our system includes two main subsystems; fresh latex transportation and concentrated latex production. The activities taken into account include electricity use, diesel use (for transportation and heating), chemicals use (ammonia, lauric acid, DAP, zinc oxide), and wastewater treatment. The functional unit is 1 ton of concentrated latex, whereas the environmental impacts considered in this study include global warming, acidification, eutrophication, human toxicity, photochemical oxidation, and the total environmental impact. Data was collected from four concentrated latex mills in the south of Thailand.
Results: The results indicate that electricity use for centrifugation has the largest share, compared with other activities, in global warming (53%), acidification (60%), and photochemical oxidation (60%). Ammonia use for latex preservation accounts for 40% of human toxicity, whereas use of DAP accounts for 60% of eutrophication. Diesel use for heating was also found to be an important contributor to several environmental impacts. Based on these results, the following cleaner technology (CT) options are therefore identified: 1) electricity efficiency improvement (by installation of inverters to centrifugal machines); 2) improvement of ammonia preparation and storage (by chilling systems); 3) minimizing the use of DAP (by extending coagulation time); and 4) substitution of diesel by LPG. These four CT options result in reductions of the total environmental impact by 12%, 8%, 3%, and 5%, respectively.
Applications of LCA and CT were found to be appropriate tools to identify options to simultaneously increase production efficiency and environmental performance of concentrated latex manufacturers in Thailand. Results from the LCA can be used to identify and prioritize the important activities (electricity use, and ammonia use in this study) associated with the environmental impact. All of the CT options presented in this study were technically and practically feasible for concentrated latex production.