Recycling: promote the harmonious development of plastic packaging materials and the environment (5)

5 Introduction to Waste Recycling Methods
5.1 Material recycling After the packaging waste is recovered, it is classified and washed, dried and pelletized, and then re-used as a raw material to produce plastic products. This recycling method has made progress in recent years, and its use has also been expanded. The following items have been successfully implemented.

·The Hamburg Hamburg Cleaning Agency established a 4kt/a waste plastics recycling plant in 2002. It collected waste plastics based on HDPE laundry detergent bottles from the recycling center, and used T&H's separation technology to produce highway noise insulation building materials and grain for imitative wood products. material. In addition to the 450-mark processing fee charged per ton from the recycling center, the price per metric ton of pellets is 320 DM, which is welcomed by users because the new price is 1400 DM/t.

· Austria's WKR company's regeneration unit is 6kt/a, and it collects waste plastics based on LDPE film from the recycling center and produces recycled pellets for black plastic garbage bags made in Italy. A mark processing fee of 1 mark per kilogram is charged. The actual cost is 0.9 mark, and then it is sold at 0.35 to 0.45 mark per garbage bag. The benefit is very good.

· France’s Micronil company has a technology that uses the impact value of PVC and PET for crushing and impact separation. This technology and its associated ethylene recycling company invest 40 million francs in accordance with the French preferential policies for renewable resources. Another 12kt/a No. 3 production line was built. The company's waste plastics recycling capacity reached 25kt/a. Another SIP company invested 78 million francs to build a 5kt/a production line of European-standard recycled plastic boards.

· The European Coca-Cola Company's 2L Coke cans made of recycled PET have been marketed in Switzerland. The structure is divided into three layers. The inner and outer surfaces are new materials, and the middle is recycled materials. US Wellman uses 100% recycled PET to produce hot-pressed containers for wild vegetables and fruit packaging.

· Japan's Nintendo Co., Ltd. and carpet fiber company jointly developed the technology of smashing and melting polyester fibers after PET bottles were used. Toyo Textile Co., Ltd. has begun to use them for the production of polyester staple fibers and textiles for clothing, and Mitsubishi Corporation Ltd. Outside sales of fabrics and garments, led by them, Dongle and Itochu Corporation also actively participated in the promotion.

· Japanese Willow packaging industry and Mitsui Petrochemical, Takeno Iron Works and other units jointly developed a successful use of waste PET bottles to make block stone technology. After the PET bottle was crushed and made into pellets, it was melted at 280°C and extruded into φ150mm, monolithic 500g blocks for road foundation. It is lighter than natural stone, has good drainage and has a low vocal tone. It not only replaces natural quarrying, but also cuts the waste to 1/20, and it is also a potential oil ore that can be extracted in an emergency.

5.2 Chemical Recycling There are three types of oilification technology for the thermal decomposition of mixed wastes (except PVC, typically PE, PP, PS, PET, etc.): 1 Simple thermal decomposition at 650–850°C under anaerobic conditions, available 50% of the liquid fuel; 2 after thermal decomposition at about 400 °C, and then into the 200 °C catalyst cabinet for contact thermal decomposition, due to the formation of heavy oil and then broken down into light oil, liquid fuel up to 80%; 3 Hydrogenation of 100 to 400 atm of high-pressure hydrogen, using a variety of raw materials for hydrogenation can also be about 80% of the liquid fuel. Hereby, Japan and Europe and the United States are introduced as follows.

Japan had more than ten households in the 1990s to carry out this research and development work, but formed only one or two households in size. After the “Recycling and Use of Related Packaging Containers” was promulgated, it was supported by the Ministry of International Trade and Development and the Ministry of Health and Welfare. Next, several development projects were carried out to focus on solving the problems of deoxidation and cost reduction, which have reached the level of practical application. The key points are as follows:

Fujitsu Recycling Co., Ltd. invested 1.1 billion yen in the early 1990s with the cooperation of Mobil Oil and built a 5kt/a plant for phase-to-phase workshops to conduct mixed waste plastics such as PE, PS and PP (excluding PVC and PET). Contact thermal decomposition test. Waste plastics are decomposed into gas at -420°C and sent into the contact reaction box at 300°C. Under the action of the pumice catalyst of ZSM-5, 1t of PE can be decomposed into 800kg of oil, 150kg of propane gas and 50kg of residue. After the oil fractionation, 50% of gasoline, 25% of kerosene and diesel oil were obtained.

The small and medium-sized business group announced that it will use the above-mentioned technology to build a 50t/a pilot plant, focusing on the problem of oiling of mixed waste plastics including PVC (~17%), PET, etc., that is, heating to about 300°C and removing the generated hydrogen chloride. Then heat decomposition.

Central Chemical Co., Ltd. used FUJI's regenerative workshop to recover 475t of foamed plastics and other impurities from supermarkets, and mixed 60t polyolefins for oiling tests. Naphtha can be recycled 85%, LPG 10%, and naphtha can be fractionated into steam. Coal and diesel can also be directly used as fuel for power generation. After preliminary estimation of a scale of 5kt/a, the processing fee is 50 yen/kg or less, so it is recommended that small and medium-sized cities can construct a device with a scale of 0.3 to 0.6 kt/a to generate electricity.

· In order to meet the requirements of the “Recycling and Use of Packaging Containers”, Tachikawa City, Tokyo Metropolitan Government, Nippon Steel Corporation, and Kubota Publishing Co., Ltd. are responsible for investing 3 billion yen in the establishment of a 10 t/a pilot project in Tachikawa City. The device uses all waste plastics from Tachikawa City to focus on solving the problem of oily plastic containing impurities. In addition, the Waste Plastics Processing Promotion Association grants 400 million yen to build a 6kt/a oiling plant (20% for PVC) in the large-scale Lube Oil Production Company (Xintang County) plant to handle mixed waste plastics in the county. .

·Equipment for environmental protection equipment has also developed its own oiling equipment. For example, Hitachi Shipbuilding Co., Ltd. built a test equipment in Ibaraki Prefecture. It uses a catalytic catalytic decomposition method and has technically passed the standard. However, the cost per l of fuel oil is 100 yen, which is the market price. 3 times, making it difficult to use. As a result, Mitsubishi Heavy Industries eliminated the catalyst after precise control of the decomposition temperature. Although the yield was slightly lower, the cost was reduced by 50%, and it is expected to be practical after suitable improvements.

European countries also attach great importance to the processing of waste plastics. Various companies are conducting trials and classify several large-scale units as follows:

Thermal decomposition

Taking German lumber company l0t/a plant as an example, the waste plastic waste from the garbage collection center will be heated at 600~800°C and 1000°C for 30 minutes, and can be decomposed into 35~58% diesel and 23~40%. Gas.

Hydrocatalytic decomposition

Taking the 20kt/a waste plastics processing plant of Germany VOAG as an example, the mixed waste plastics can be decomposed into 80% liquid fuels and others at 460-490°C and 200 bar using hydrogen and alkali as catalysts.

·Contact thermal decomposition

Take the test equipment of BP Chemical Company in the UK as an example. The mixed waste plastics (80% PE, 15% PS, 3% PET, 2% PVC) are heated in a fluidized bed at 450-500°C to produce LPG. , Has now completed 28kg / h test, plans to build 25kt / a production plant.

· BASF has invested 40 million marks to build a 15kt/a plant for processing waste plastics. First, waste plastics are heated to 300°C in isolated air, HCL produced by PVC is collected and used for hydrochloric acid production, and various oils and gases produced when the temperature rises to 400°C are sent to each workshop to produce raw materials for PP and PE respectively. 3 to 10% of the residue, and plans to invest 350 million mark to build 300kt/a.