Establishment of Industrial Symbiosis Network through Recovery of Benzoic Acid from Petrochemical Waste

다국어 초록 (Multilingual Abstract)

Reuse, recycling and recovery (3R) of industrial wastes are common and encouraging in Korea. Industrial symbiosis is one of typical methods for implementing 3R and has been defined as engaging “traditionally separate industries in a collective approach to competitive advantage involving physical exchange of materials, energy, water, and by-products”. The keys to industrial symbiosis are collaboration and the synergistic possibilities offered by geographic proximity. Recently, several countries in East Asia such as Taiwan, South Korea, Japan and China are promoting ‘designed’ symbiosis networks in various industrial complexes based on their national Eco-industrial Park (EIP) demonstration programs. Despite the recently promoted EIP initiatives worldwide, only very few studies furnish the operational and functional details of ‘designed’ industrial symbiosis networks, starting from the planning to implementation stage. The production of terephthalic acid (TPA) in Korea is 6.5 million ton based on 2011. The production of waste generated in the process of TPA is about 15,000 ton/yr and included useful materials like residue TPA as well as isophthalic acid (iPA), benzoic acid (BA) and p-toluic acid (p-TL). Until now, TPA waste was incinerated due to high caloric value. This study was conducted for recovery of valuable materials from industrial waste and utilization of recovered material as an example of Korean EIP. In this study, the experiment was performed to separate above four materials from the waste by solvent (methanol and water) extraction. The solubility of TPA (0.1g/100g) for methanol is relatively low compared to other materials. Also the solubility of BA (68g/L at 95℃) and p-TL (11.6g/L at 98℃) for water is relatively high in comparison with other materials. Finally, BA was separated from p-TL by molecular distillation system. The purity of recovered materials was analyzed by ultra-high performance liquid chromatography (Waters Xevo TQ system). The recovery rate and purity of BA is 90% and 93%. The recovered BA could be recycled the companies which are produced plastic plasticizer and paints.