The development of naturally degradable plastic products to replace commonly used ordinary plastic products has become a hot spot in the 1990s, but at that time, the development of degradable plastics was slow due to cost and technical problems. In recent years, with the progress of raw material production and product processing technology, biodegradable plastics, especially biodegradable plastics, have received renewed attention and become the highlight of sustainable and circular economic development. At the same time, they have once again become the focus of the world. It is necessary and meaningful to develop degradable plastics, whether in terms of energy substitution, carbon dioxide reduction, environmental protection and partially solving the 'three rural' problems.
Current situation and development trend of biodegradable plastics at home and abroad
In terms of raw materials, there are at least the following types of Biodegradable Plastics:
1. Polycaprolactone (PCL)
This kind of plastic has good biodegradability, and its melting point is 62 ℃. The microorganisms that decompose it are widely distributed under the conditions of euphoria or anorexia. As a biodegradable material, it can be mixed with starch and cellulose materials, or polymerized with lactic acid.
2. Polybutylene succinate (PBS) and its copolymers
The technology of manufacturing various high molecular weight polyesters based on PBS (melting point: 114 ℃) has reached the level of industrial production. Mitsubishi Chemical and Showa polymer companies in Japan have begun industrial production, with a scale of about 1000 tons.
The Institute of physics and chemistry of the Chinese Academy of Sciences is also conducting research on the synthesis of polybutylene succinate copolyester. At present, the Institute of physics and chemistry of the Chinese Academy of Sciences is preparing to build a PBS production line with an annual output of million tons, and Guangdong Jinfa company has built a production line with an annual output of 1000 tons.
3. Polylactic acid (PLA)
NatureWorks of the United States has done active and effective work in improving the production process of polylactic acid, and developed the fermentation of glucose in corn to produce polylactic acid, with an annual production capacity of 14000 tons. Unitika company of Japan has developed and produced many kinds of products, among which canvas, tray and tableware are widely used in the Aichi Expo in Japan.
At present, Zhejiang Haisheng biodegradable plastics Co., Ltd. (with a production line of 5000 kt / a) is industrialized in China, and the units under pilot test include Shanghai tongjieliang biomaterials Co., Ltd. and Jiangsu Jiuding group.
4. Polyhydroxyalkanoates (PHA)
At present, countries such as the United States and Brazil have achieved industrialized production abroad. At present, the domestic production units include Ningbo Tian'an biomaterials Co., Ltd. (with a scale of 2000 tons / year), and the units under pilot test include Jiangsu Nantian Group Co., Ltd. and Tianjin Guoyun Biotechnology Co., Ltd.
The technology of producing degradable plastics by mixing aliphatic polyester and starch with biodegradable plastics obtained from renewable resources has also been successfully studied. In Europe and the United States, the blend of starch and aliphatic polyester is widely used to produce garbage bags and other products. Novamont, an Italian company with a trade name of mater Bi, is the largest and best-selling company in the world. Its products are widely used in Europe and the United States.
There are many domestic research and production units, including Wuhan Huali Technology Co., Ltd. (with a scale of 8000 tons / year), Zhejiang HUAFA Ecological Technology Co., Ltd. (with a scale of 8000 tons / year), Zhejiang Tianhe Ecological Technology Co., Ltd. (with a scale of 5000 tons / year), Fujian Baishida biomaterials Co., Ltd. (with a scale of 2000 tons / year), Zhaoqing Huafang degradable plastic Co., Ltd. (with a scale of 5000 tons / year), etc.
5. Aliphatic aromatic copolyester
Aliphatic aromatic random copolyester (ecoflex) manufactured by BASF company in Germany, whose monomers are adipic acid, terephthalic acid and 1,4-butanediol. The current production capacity is 140000 tons / year. At the same time, biodegradable plastic products based on polyester and starch have been developed.
6. Polyvinyl alcohol (PVA) biodegradable plastics
For example, matterbi products of novmant in Italy mainly added PVA into starch in the 1990s, which can blow film and process other products. Polyvinyl alcohol materials need to be modified to have good biodegradability. The Institute of light industrial plastics processing and application of Beijing University of technology and industry has made some achievements in this regard.
7. Carbon dioxide copolymer
Abroad, Japan and the United States are the first countries to study carbon dioxide copolymers, but there has been no industrial production.
Using the technology of Changchun Institute of Applied Chemistry, Inner Mongolia Mengxi group company in China has built a device with an annual output of 3000 tons of carbon dioxide / epoxy copolymer resin. The products are mainly used in packaging and medical materials. The low molecular weight carbon dioxide copolymer technology developed by Dr. Chen Liban of Guangzhou Institute of chemistry, Chinese Academy of Sciences has been put into production in Taixing, Jiangsu Province. The variety is low molecular weight carbon dioxide / epoxy copolymer, which is used as raw material of polyurethane foaming materials and packaging of household appliances. Using the technology of Professor Meng Yuezhong of Sun Yat sen University, Henan Tianguan Group has built a pilot scale carbon dioxide copolymer production line, which is expected to be put into pilot production this year.
Others such as chitin, polyamide, polyaspartic acid, glycan, cellulose, etc. are under development.
Development status and trend
According to the data of Japan Biodegradable Plastics Research Association, the production of biodegradable plastics in Japan was about 10000 tons in 2002, 20000 tons in 2003, 40000 tons in 2005, and is expected to reach about 100000 ~ 200000 tons by 2010.
According to the European bioplastics Association, the figures in 2001 show that the consumption of biodegradable products in the European Union is 25000 ~ 30000 tons, while the consumption of traditional polymers is as high as 35million tons. The European bioplastics Association predicts that the consumption of traditional polymers will reach 55million tons in 2010, while the consumption of biodegradable plastics will reach 500000 ~ 1million tons at that time. Biodegradable materials may eventually account for 10% of the market share. Renewable resources will account for more than 90% of biodegradable materials.
According to the statistics of the degradable plastics professional committee of China Plastics Association, the consumption of biodegradable materials in China in 2003 was about 15000 tons, including about 1000 tons of biodegradable polymers without starch. In 2005, there were about 30 enterprises engaged in biodegradable plastics, with a production capacity of 60000 tons / year, an actual production of about 30000 tons, a domestic market demand of about 50000 tons, a foreign import of 10000 tons and an export of 20000 tons. It is estimated that the production capacity will reach about 250000 tons in 2010.
Domestic and foreign policies
Some developed countries also use biodegradable disposable utensils under the guidance of the idea of circular economy, such as Sweden's trial production of disposable fast food boxes made of potato and corn in the late 1980s, and South Korea's mandatory use of toothpicks made of glutinous rice by law. Europe has formulated the standard EN13432 'requirements for the test and final evaluation of packaging materials conducive to composting and biodegradation for recycling' related to biodegradable composting plastics, while other decrees related to promoting the composting treatment of organic wastes are actively being formulated and prepared. The U.S. government has set up the Presidential Green Chemistry Challenge Award since 1996 to encourage the development of biodegradable plastics industry. In 1989, the state of New York banned the use of non biodegradable vegetable bags, subsidized manufacturers of degradable plastics, and required citizens to separate renewable and non renewable waste, otherwise they would be fined $500.
Other countries have taken similar measures: India has legislated to prohibit the use of plastic packaging in the dairy industry; South African law has completely banned the use of plastic packaging bags. With the development of national legislation, biodegradable new packaging materials are expected to become increasingly popular.
In China, with the deepening understanding of degradable plastics, the strategic role of this material and its industry in China's sustainable development has been fully recognized. The popularization and application of biodegradable plastics has been widely expected. In 2004, the Chinese people's Congress passed the renewable energy law (Draft) and the solid waste law (Revised), encouraging the utilization of renewable biomass energy and the promotion and application of degradable plastics. In the No. 40 document of the national development and Reform Commission in 2005, it is also clear to encourage the use and promotion of biodegradable plastics. In 2006, the national development and Reform Commission launched a special fund project on promoting the development of biomass biodegradable materials.
Problems and difficulties in the development of biodegradable plastics
Biodegradable plastics, as a new technology to treat plastic waste, has made satisfactory progress after years of research and development. But there are also some problems: such as difficult processing, expensive price and so on; In addition, technical problems such as more reasonable process formula need to be further improved and perfected.
Suggestions on policies and measures for industrial development
（1） Accelerate product application research and development and industrialization
At present, the performance of biodegradable plastic products can not fully meet the needs of consumers. Although there are many varieties in the market at present, the mechanical and processing properties of each material itself only have prominent characteristics in one aspect, and there are still some deficiencies in its comprehensive performance, which will be one of the bottlenecks restricting its market application and promotion. While developing biodegradable plastic products, domestic enterprises should pay attention to accelerating the development of innovative products and uses with independent intellectual property rights. Due to the relatively early research and development, production and application of biodegradable plastic products in foreign countries, many patents have been applied for, which has created certain technical barriers for domestic enterprises to develop new products. Take polylactic acid patents as an example. In 2005, there were more than 1700 foreign patents related to polylactic acid, while only 145 patents were published in China, and more than half of them were patents of foreign companies. Therefore, domestic enterprises should strengthen the development of products with independent intellectual property rights.
（2） Strengthen research on product processing and development
Secondly, at present, the strength of domestic research on product processing is still weak. Most enterprises focus on material synthesis and ignore product processing and development. Some catering utensils made of biodegradable plastics are far from traditional plastic products in terms of heat resistance, water resistance and mechanical strength, which is precisely the key to the large-scale Marketization of biodegradable plastics.
（3） Improve the garbage recycling and treatment system and promote the recycling process of biodegradable plastics
The lack of a complete recycling system also restricts the further promotion of products. Therefore, degradable plastics must be clearly identified and recycled. Those that can be reused are collected and then molded into products; For those that cannot be reused, reasonable treatment methods should be considered. For degradable plastics with renewable resources such as starch added to traditional plastics, a waste treatment system with heat recovery can be adopted. For biodegradable plastics, the treatment method of composting can be emphatically considered.
（4） Accelerate the formulation of relevant policies and regulations
1. Special fund support
Adopt subsidy policies for the application and development of biodegradable plastic products, including central government subsidies and local government subsidies. The central government can provide subsidies through scientific and technological research funds and discount interest, such as the demonstration and promotion of disposable biodegradable plastic products for the Olympic Games.
The state may consider adopting low interest loan policies, special loans for technological transformation, credit guarantee policies, etc. to encourage industrial development for enterprises that use biomass raw materials to produce biodegradable plastics.
2. Tax policy
At present, there is no explicit provision on the low tax rate for the import of biodegradable plastics products, and preferential tariff rates should be formulated to promote the development of the industry.
In order to encourage and support the development of some enterprises, preferential policies can be reduced or exempted in accordance with the new enterprise income tax regulations. For example, first, enterprises in ethnic regional autonomous areas that need to be cared for and encouraged can be reduced or exempted regularly with the approval of the provincial people's government; Second, enterprises that are granted tax reductions and exemptions by laws, administrative regulations and relevant provisions of the State Council shall implement the provisions.
3. Strengthen the recycling of traditional plastics and increase the recycling tax
Foreign countries attach great importance to the recycling of plastic products after use. For example, according to the guiding law revised by the European Commission, EU Member States should increase the recycling rate of their packaging waste to more than 55% from 2008 to 2015, including glass packaging recycling rate of 60%, metal packaging rate of 50%, plastic packaging rate of 22.5%, and wood packaging rate of 15%. The European Commission pointed out that in 2001, the recycling of packaging waste alone reduced carbon dioxide emissions in the EU by 0.6%, which shows that improving the recycling rate of packaging waste can not only reduce the energy consumption of packaging materials and save the cost of building incineration treatment plants, but also reduce the environmental pollution caused by the production process of packaging materials, which is a very practical and effective measure to reduce greenhouse gas emissions and protect the environment. Therefore, we must strengthen the compulsory recycling of traditional plastics. For disposable plastic packaging products with high recovery costs, a 10% - 100% recovery tax will be charged. For disposable plastic packaging products that cannot be recycled, biodegradable plastics must be used.
There has been a precedent abroad for taxing traditional plastic disposable products for a long time. In March, 2002, the Irish government began to levy a value-added tax on plastic bags. According to the regulations of the Irish government, customers will levy a tax of 15 euro cents for each plastic bag they use when shopping in the market. The number of plastic bags used in Ireland is staggering, with 1.2 billion free plastic bags distributed to shoppers every year, weighing 14000 tons. The average person will consume about 325 plastic bags a year. Within one month after the value-added tax on plastic bags came into effect, the consumption of plastic bags plummeted by more than 90%.
4. Appropriately restrict the disposable non degradable packaging products made of some traditional plastics
Appropriately restrict or even prohibit some disposable non degradable packaging products made of traditional plastics by stages and batches, such as disposable garbage bags, shopping bags, daily necessities outer packaging, disposable tableware, disposable plastic cups, disposable food packaging containers, disposable food packaging films, disposable industrial packaging, etc.
5. Promote degradable plastics by stages and batches
According to the industrial production capacity and product production technology, gradually promote the promotion progress of degradable plastics. Before 2010, policy support was given to these two types of products, with the promotion of biodegradable plastics as the main line and the blending of traditional plastics with natural materials such as starch, but the former was stronger than the latter. After 2010, biodegradable plastics will be comprehensively promoted, and traditional plastic products added with starch will no longer enjoy preferential policies.
6. Strengthen the bridge role of industry associations
Strengthen the role of the degradable plastics professional committee of China Plastics Processing Industry Association as an industry bridge, give financial support to the industry association, use the industry association to strengthen the guidance of enterprise investment, production direction, product positioning, etc., promote internal and external exchanges, promote domestic and international exchanges and trade, as well as sufficient policy research and industry statistics |