Bio-Based Plastics: Widespread Use Is Imminent

By Weng Yunxuan, Degradable Plastics Committee of China Plastics Processing Industry Association

Biodegradable bio-based plastics

1. Dibasic acid/dibasic alcohol copolymers (PBS, PBSA and PBAT)

China’s capacity to make dibasic acid/dibasic alcohol copolymers (poly butylenes succinate (PBS), poly(butylene succinate-co-butylene adipate) (PBSA) and poly(butylene adipate-co-terephthalate) (PBAT)) exceeds 100 kt/a.
Major producers include Changmao Biochemical Engineering Co., Ltd., which has constructed a 10 kt/a succinic acid production line using a biological fermentation process; Anqing Hexing Chemical Co., Ltd., which has constructed a 10 kt/a PBS project; Hangzhou Yifan Xinfu Pharmaceutical Co., Ltd., which has constructed a 13 kt/a PBS and PBAT production line; Guangzhou Kingfa Science & Technology Co., Ltd., which has constructed a 30 kt/a PBSA production line; Shandong Yuetai New Material Co., Ltd. (formerly Shandong Huiying New Material Co., Ltd.), which has constructed a 25 kt/a PBS and PBAT production line; Xinjiang Blue Ridge Tunhe Chemical Industry Joint Stock Co., Ltd., which owns a 5 kt/a film-grade PBS and PBAT unit and is constructing a 30 kt/a production line today; and Jinhui Zhaolong High-Tech Co., Ltd., which has constructed a 20 kt/a PBS and PBAT production line.

2. Polylactic acid (PLA)

China’s apparent consumption of PLA exceeds 22 kt now. The products are sold mainly to overseas markets. Zhejiang Hisun Biomaterials Co., Ltd. has expanded its PLA capacity from 5 kt/a to 15 kt/a and started construction of a 50 kt/a PLA production line at the end of 2014. Jiangsu Suqian Yunyoucheng New Composites Co., Ltd. has started debugging its new 10 kt/a PLA production line. A 4 kt/a PLA fiber resin production line of Jiangsu Yizheng Chemical Fiber Textile Co., Ltd., a 10 kt/a PLA production line of Jiangsu Jiuding New Materials Co., Ltd. and a 10 kt/a PLA resin production line of Anhui Maanshan Tongjieliang Biomaterials Co., Ltd. passed acceptance tests in 2014. A Xiaogan-based 1 kt/a PLA production line of Shenzhen Guanghua Weiye Industrial Co., Ltd. can start production at any time. Construction preparations are complete for a 10 kt/a PLA production line of Jilin COFCO Biochemical Co., Ltd., a 10 kt/a PLA production line of Shandong Golden Corn Biochemical Co., Ltd. and a 10 kt/a PLA production line of Henan Nanle Longdu Tianren Biomaterials Co., Ltd.
As the scale of PLA plants in China is quite small and industrial chains and industrial clusters have not yet been effectively formed, production costs are high, and some high-end equipment and raw materials such as lactide must be imported. However, the processing and production of some products – such as disposable packages, shopping bags, cutlery and fiber products – are already very competitive in the international market.

3. Poly propylene carbonate (PPC)

Major PPC research in China occurs at CAS Changchun Institute of Applied Chemistry, CAS Guangzhou Institute of Chemistry, Zhejiang University and Zhongshan University. Zhejiang Taizhou Bangfeng Plastics Co., Ltd. has used patented technology from CAS Changchun Institute of Applied Chemistry since June 2010 and constructed a 10 kt/a PPC production line in 2012. Henan Tianguan Group Co., Ltd. used carbon dioxide capture technology to construct a 5 kt/a PPC commercial production line. The company owns over 10 patents. Jiangsu Zhongke Jinlong Chemical Co., Ltd. has constructed a 22 kt/a PPC production line and a 1.60 million m2/a line for flame-retarding, heat-insulating material. Nantong Huasheng Polymer Technology Development Co., Ltd. started to develop PPC modification and film processing technologies in December 2007 in collaboration with CAS Changchun Institute of Applied Chemistry. Plastic films produced by the company are exported to the United States, Japan and the EU.

4. Polyhydroxyalkanoates (PHA)

Enterprises producing PHA on a large scale in China include Ningbo Tian’an Biomaterials Co., Ltd., whose PHA capacity has reached 2 kt/a, and Tianjin Guoyun Biomaterials Co., Ltd., which has already constructed a 10 kt/a PHA production line in Tianjin and plans to construct a new 100 kt/a PHA plant in Jilin after cooperation with Beijing Fuchuang Investment Co., Ltd. begins.

5. Polycaprolactone (PCL)

PCL displays huge potential in the research of clinical medicine, owing to its excellent properties in the dispersion and penetration of drugs and their long-time stable release. PCL research in China is conducted at Sichuan University and Wuhan University. Sichuan University has used a one-step hexylene glycol process to synthesize caprolactone monomer, and the production process is “green” and environment-friendly. Shenzhen Guanghua Weiye Industrial Co., Ltd. has used ε-caprolactone with metallic organic compounds (such as tetrapropyltin) as catalyst and produced PCL through ring-opening polymerization with dihydroxy group or trihydroxy group as initiator. The company constructed a 0.5 kt/a PCL pilot production line at the end of 2007 and now plans to construct a 2 kt/a PCL production line.

6. Thermoplastic biomass plastics

Enterprises that have started commercial production or conducted pilot production of thermoplastic starch-based plastics include Wuhan Huali Biomaterials Co., Ltd., Guangdong Yide Environmental Protection Technology Co., Ltd., Suzhou Hanfeng New Materials Co., Ltd., Zhejiang Tianhe Ecological Technology Co., Ltd., Zhejiang Huafa Ecological Technology Co., Ltd., Biograde (Nanjing) Environmental Protection Materials Co., Ltd., Guangdong Shangjiu Biodegradable Plastics Co., Ltd., Yantai Sunshine Australia Environmental Technology Co., Ltd., Changzhou Longjun Environmental Protection Industrial Development Co., Ltd. and Zhaoqing Huafang Degradable Plastics Co., Ltd. Moreover, Wuhan Huali Biomaterials Co., Ltd. has established a complete industrial chain. The company has already constructed a 60 kt/a R&D and production base of bio-based plastics and products with cassava starch and stalk fiber as major raw materials. Suzhou Hanfeng New Materials Co., Ltd. has a capacity of 40 kt/a cassava modified starch and a capacity of 30 kt/a granular materials and products. Products include modified starch, filler masterbatch, special materials, sheets, film bags, injection-molded products and vacuum-molded products. Zhejiang Tianhe Ecological Technology Co., Ltd. owns a capacity of 35 kt/a for whole-series bio-based materials and products (such as blow-molded products, vacuum-molded products and injection-molded products). Zhejiang Huafa Ecological Technology Co., Ltd. has a capacity of 8 kt/a. Changzhou Longjun Environmental Protection Industrial Development Co., Ltd. has a capacity of 8 kt/a.

Non-degradable bio-based plastics

1. Polyamide (PA)

Unlike petroleum-based PA, monomers of bio-based PA come from renewable substances (such as castor oil and glucose). The main kinds of totally bio-based PA are PA11 and PA1010. The main kinds of partially bio-based PA are PA610, PA1012, PA410 and PA10T. Production processes for PA are mainly classified according to the source of biomass as the grease route and the polysaccharide route. The grease route mainly uses castor oil as raw material. Bio-based PA11 is produced through the polymerization of ω-undecyl amino acid as monomer. Bio-based PA12 is produced through the polymerization of ω-dodecyl amino acid as monomer. Bio-based PA1010, PA1012, PA610, PA410 and PA10T are produced through the polycondensation of dibasic acids and dibasic amines, and the starting raw material is totally or partially castor oil. Polysaccharide includes glucose and cellulose. The route for the production of bio-based PA from glucose is quite well developed. The output of bio-based PA66 fiber in the world will exceed 1.00 million tons in 2022, according to estimates made by Rennovia of the United States.
Enterprises related to bio-based PA are developing steadily in China. Major bio-based PA producers include Suzhou Hipro Polymers Co., Ltd., Shanghai KS Holdings Co., Ltd. and Guangdong Kingfa Science & Technology Co., Ltd. Now, Zhengzhou University and Shandong Tuopu Biomaterials Co., Ltd. are cooperating to construct a 10 kt/a demonstration production line for long-chain dibasic acid and PA resin.

2. Poly(trimethyleneterephthalate) (PTT)

PTT is a polyester produced through polycondensation using terephthalic acid and 1,3-propylene glycol as major raw materials. 1,3-Propylene glycol can be obtained through oxidation or reduction using a biological process.

3. Polyurethane (PU)

Bio-based PU products include PU based on grease, PU based on polysaccharide and PU based on amino acid. PU based on grease is already commercially produced, owing to its excellent properties and very mature technology, and the products are used in making heat-insulating materials, seats, coatings, adhesives and sealants.

Industrialization

Bio-based plastics are at the initial stage of industrialization today. As biodegradable plastics meet requirements of advanced countries in Europe and America banning the use of plastic bags, they have considerable market opportunities, even if their cost is high. In the long view, some non-degradable bio-based plastics will likely find considerable applications in the international market. In China, however, pilot production of such materials has not been achieved.
While capacity is still increasing, PLA makers already face competition risks. The price of PLA from NatureWorks of the United States is much lower than domestic products. Furthermore, a Thailand-based 100 kt/a PLA plant of that company, using cassava starch as raw material, is expected to start production soon.
China’s capacity for PBS and PBAT already exceeds 100 kt/a. Six producers are in large-scale production. The apparent consumption is however only around 15 kt. Shandong Landian Biological Technology Co., Ltd. also plans to construct a 100 kt/a PBS production line. PBS capacity is already in surplus. Pilot production plants already exist for dibasic acid/dibasic alcohol copolymers, including polymers such as PTT, but there are no competitive suppliers of bio-based chemical raw materials, and the costs of mass production and the performance of products in applications both remain uncertain.