Thoughts on promoting the practical process of bio

Thoughts on promoting the practical process of biodegradable plastics (Part 1)

1 background

since entering the 21st century, the global economy has continued to grow, the economy of developed countries has continued to develop steadily, and the economy of developing countries has shown a trend of rapid growth. Coupled with the expansion of the global population and the wanton development of resources, the already scarce energy has become more tense, the dwindling non renewable resources have become poorer, and the fragile environmental problems have become increasingly serious. How to build a society with harmonious development with resources and environment, circular economy and sustainable development is a problem that countries, all industrial departments and as a member of society must seriously face, and it is also the main direction of social development

as we all know, for traditional materials, plastic is a new kind of material. Its light weight, good comprehensive performance, easy processing and many other advantages have been favored by the society and the masses. It has been widely used in industry, agriculture and all aspects of people's life. It has made up for the shortcomings of other traditional materials in terms of quality and quantity in many application fields. It plays a great role in the national economy and brings great convenience to people's life, It has become an indisputable fact. However, everything has its two sides. With the continuous expansion of the application of plastic materials, especially disposable plastic products such as packaging film (bag), catering utensils, mulch, and the increasing consumption, its waste is difficult to collect and is not easy to degrade in the natural environment. The environmental problems caused by this have been heavily criticized by the society. In the past, plastic waste in foreign developed countries was mainly treated by landfill and incineration together with municipal solid waste (MSW), but these treatment methods also have many shortcomings and negative effects; Recycling (including materials, energy, fuel, fertilizer, etc.) is an effective measure to solve the environmental pollution and resource reuse caused by MSW, but in real life, not all plastic wastes are easy or suitable for recycling. On the other hand, plastic materials, which developed rapidly in the 20th century, are mainly derived from petrochemical resources, and the formation process of petrochemical resources requires thousands of years. These factors lead to the rapid oxidation of materials for millions of years, so they can be regarded as non renewable resources. According to data reports, the world's exploitable and proven reserves of fossil fuel resources can only be provided for another 50-100 years based on the current consumption level. According to Japanese data reports, the world's oil can be exploited for more than 40 years and natural gas for more than 60 years. Although new mineral sources will be found, it must also be noted that due to the growth of population and the continuous improvement of people's living standards in developing countries, demand will further increase, The above mining years will also be affected to a certain extent. At that time, the price of petroleum fuels will inevitably increase, and the price of petrochemical products will also increase significantly. Therefore, for the development of the plastic industry, the limited resources are very worrying. At present, the governments and industries of developed countries in Europe and the United States are studying and formulating strategies to use renewable resources to supplement or replace the fossil fuel resources that are currently too dependent, non renewable, decreasing and facing depletion. Therefore, from the perspective of sustainable development, energy conservation and resource substitution have become an irresistible trend. Under such a historical background, the research and development of biodegradable plastics (BDP) and accelerating the process of practicality and industrialization have become a hot spot of global attention. 1

2 profile

in recent years, the United States, Japan, Europe and other countries attach great importance to BDP, especially the development of biomass plastics whose raw materials come from renewable resources or comprehensive utilization of waste gas (such as CO2). According to data report 2, the BDP market scale in the world in 2002 was 90~105kt, including 50~60kt in the United States, 30~35kt in Germany and 10kt in Japan

American nature works (formerly gargill Dow) company has built a 140kt/a polylactic acid (PLA) with starch as raw material. Its trade name is "nature works". It is said that the output reached about 70KT in 2004, and its cost has been reduced from 8000 US dollars/t to 2000~2500 US dollars/t. This production line is the largest BDP production line in the world. In addition to stepping up the application and development in the United States, its products are mainly exported to Japan, Germany and other countries, We are vigorously exploring applications. In addition, the chemical synthesis system BDP aliphatic/aromatic copolyester developed by Du Pont and Eastman Chemical, with trade names of "Biomax" and "Eastar bio" respectively, has built a 10000 ton scale production line; Polycaprolactone (PCL) developed by Dow Chemical Company, with the trade name "tone", has been built with an annual production scale of 4.5kt, and has been put into mass production; Other products include polyvinyl alcohol (PVA) developed by environmental products, which has an annual production scale of 10kt

Europe has also stepped up the development of BDP in recent years. The commercialized products in Germany include starch based plastics developed by bio tec (bio teke) company. If the fault is eliminated, they can manufacture tableware, trays and films alone or mixed with other varieties of BDP, and the trade name is "bio plast"; The aliphatic/aromatic copolyester developed by BASF company has built an annual production scale of 8kt, and its trade name is "ecoflex"; Bayer has successfully developed starch/polyurethane blended BDP, which has been patented in the United States and Europe. The starch/bdp (PCL, PVA, PLA, etc.) plastic alloy "mater Bi" developed by novamant (Norman) Company in Italy is the first BDP to be put into the market, and has built an annual production scale of 20kt. Rodenburg biopolymer company in the Netherlands has successfully developed the starch based plastic "salany L" with waste potato peel as raw material. It has built a pilot scale factory with an annual output of 1000 tons and has been mass produced

Japan is one of the countries with the most active R & D and application development of BDP. In particular, it has invested considerable human, financial and material resources in the development of application technology, and has made gratifying progress in the field of packaging and non packaging. The main feature of Japan's development is that in addition to strengthening the research and development of products with independent intellectual property rights in its country, a considerable force is to cooperate with foreign companies that have already produced on an industrial scale, import commercialized products according to different characteristics and market needs, and strengthen market development and market cultivation, thus greatly shortening the commercialization process. At present, the products that have entered into practical use include aliphatic polyester (PBS) "GS PLA" and "GS PLA" with an annual output of 3kt built by Showa polymer company and Mitsubishi Chemical/monosodium glutamate company respectively; The chemical industry company produces 1kt of PCL and its copolyesters "pH" and "GBS"; クラレレルレレレレアィセロロロ chemical company has produced PVA on an industrial scale, and the trade names are "ボバルルゴセノルルドロン VA" respectively (see Table 1 for details)

Table 1 the development of biodegradable plastics in Japan and the production profile of major companies in Europe and the United States (data before June 2003) 2, 3

normal> classification

normal> polymer name

normal> trade name

normal> manufacturing enterprise

normal> scale t/a ①

normal> remarks

normal> microbial production system

normal> electric heating wire core preheating device is adopted in the extrusion unit.> polyalkyl butyrate (PHB)