By Wang Min and Mao Xiaoyang
China’s enterprises engaged in biodegradable plastics – an ideal alternative to petroleum-based plastics amid growing awareness of low-carbon development and environmental protection – are developing rapidly, given factors such as rising demand, policy support, etc. At present, raw material supply of biodegradable plastics is sufficient, and key progresses have been made in some technologies. Further, industry concentration is expected to increase. However, problems regarding core technologies, high production costs and scale application still exist.
Current situation of China’s biodegradable plastics industry
1. Stable supply of raw materials and progresses in some technologies
Biodegradable plastics are mainly produced by corn and straw. Other raw materials include soybean, starch, etc. Exceeding 650 million tons for the seventh year in a row, China’s grain output reached 682.85 million tons in 2021, with grain for industrial uses accounting for around 20%. China’s output of corn has stayed at 255-265 million tons from 2015 to 2020, and around 25% has been used in industrial consumption. Hence stable sources of raw materials of biodegradable plastics.
In spite of conducting technical research relatively late, domestic biodegradable plastics enterprises and research institutions have developed a batch of technologies with independent intellectual property rights. COFCO Biotechnology has developed continuous reaction PLA technology, and PhaBuilder has developed next-generation industrial biotechnology. Production technology patents are mainly related to important auxiliary materials (e.g. plasticizers) and reaction equipment (e.g. flash tanks).
2. Faster growth and trend of concentrated development
Entering a "double carbon" era, key chemical enterprises make more efforts to develop biodegradable plastics, trying to break technical bottleneck. More specifically, scale production of starch-based biodegradable plastics has been realized in some companies like Wuhan Huali, Hongcai Technology, etc. Some firms (e.g. Jindan Technology, Wanhua Chemical, etc.) are actively constructing PLA projects. Some enterprises (e.g. COFCO Biotechnology, PhaBuilder, etc.) are optimizing PHA production technologies and propelling industrial application. Meanwhile, in some areas, where bio-based materials are regarded as a key green industry, industrial clusters/bases are upgraded or established, such as: 1) biodegradable materials and products innovative industrial cluster located at Yingkou High-tech Zone in Liaoning Province and expected to develop into a RMB100 billion-grade cluster; 2) new bio-based material industrial base located in Bengbu of Anhui province and founded to link upstream raw material lactic acid and downstream bio-based fibers and plastics production lines.
3. Increasing demand
China issued the policy to restrict use of plastic shopping bags in 2008. However, consumption of disposable plastic products has skyrocketed due to burgeoning express and take-out industries. Hence, more documents were issued, such as: 1) Opinions on Strengthening Plastic Pollution Control calling for gradually banning or restricting use of non-degradable plastic bags and promoting use of degradable substitutes; 2) Development Plan for Biological Economy (2021-2025) calling for utilizing degradable material products mainly in the areas of agricultural mulching films, packing materials, etc. Stimulated by related policies, biodegradable plastics will become main substitute for traditional plastics – especially in industries like agricultural mulching films and disposable packaging materials.However, at present domestic demand for biodegradable plastics relies on imports heavily. Rising 20.6% annually, PLA import volume soared from 2 661 tons in 2010 to 25 295 tons in 2021, far exceeding export volume during the period, according to data from the General Administration of Customs (see Figure 1 for details). Therefore, China’s biodegradable plastics market has great growth potential.
Figure 1 China’s PLA import and export during 2010-2021
Problems facing China’s biodegradable plastics industry
1. Technical bottleneck
Domestic biodegradable plastics producers have to solve many technical difficulties, e.g. synthesis and purification reaction of intermediate lactide, separation and purification during PHA microorganism synthesis, improvement of compatibility and blending property of starch-based materials, etc. If biodegradable plastics producers want to compete with manufacturers of petroleum-based plastics, they have to overcome these technical difficulties.
2. High production costs
Benefiting from relatively high degree of industrialization, production costs of starch-based materials are basically the same as petroleum-based degradable materials’. However, producing PLA and PHA will cost producers more than producing petroleum-based degradable materials. Such situation can hardly change in a short term. To reduce the costs, technical breakthroughs and scale production will matter greatly.
3. Necessity to realize application scale
Low output and high costs prevent application market of biodegradable plastics from further expanding, despite progresses including initial scale application of starch-based materials and PLA, rising capacity and consumption of PHA, etc. Some enterprises like Anhui Fengyuan and Kingfa Sci. & Tech. develop rapidly, but domestic output of biodegradable plastics is far lower than demand.
Suggestions
Biodegradable plastics enterprises should make breakthroughs in lactide synthesis and purification, PHA separation and extraction and other core technologies. Cooperation between enterprises and universities is recommended, as this will effectively convert the achievements in scientific research to help firms increase capacity and speed up industrialization. Further, technology introduction should be strengthened, but enterprises should pay attention to technological re-innovation and intellectual property protection.
For materials (e.g. starch-based materials and PLA) realizing scale production, enterprises should speed up capacity expansion – through optimizing technologies, constructing new production lines, etc. – to further reduce production costs. Meanwhile, R&D on modified materials and composite materials should be strengthened. For materials (e.g. PHA) with low degree of industrialization, enterprises should reduce production costs via measures like using biological wastes as raw materials, in an attempt to increase capacity and expand production scale. In addition, more biodegradable plastics industrial cluster should be established.
National policies regarding “double carbon” and “restriction of plastic bags” have propelled consumption of biodegradable plastics. Enterprises should optimize product properties, diversify products and reduce use-costs to stimulate downstream demand. Further, biodegradable plastics producers should improve international competitiveness and expand overseas markets.
