Polylactic acid capacity will enter the million-ton scale in few years, will it replace traditional plastics?
l Degradable Plastic Technology and Market Forum 2019 will be held on April 24-25 in Kunming, Yunan, China
l Key technologies for polylactic acid synthesis will be an important topic of the forum
l This forum will also discuss high value innovative application of PLA materials
Traditional polymer materials bring countless conveniences to people, and they also bring a lot of burden to the environment. "White pollution" is becoming an increasingly serious problem. Under this background, polylactic acid (PLA), as the fastest biodegradable material in industrialization in recent years, can achieve rapid degradation under certain conditions, and has received more and more attention. In 2019, the global and Chinese PLA projects were booming, with a planned production capacity of over one million tons. PLA is widely used in injection molding, film, sheet and fiber, and has the potential to gradually replace traditional plastics in the future.
"Made in China 2025" listed PLA and other biodegradable materials as the key development targets of polymer materials; the Ministry of Science and Technology's "13th Five-Year Plan for Innovation in the Field of Materials" clearly states that technological improvement and industrial upgrading of new bio-based materials such as high-temperature resistant polylactic acid are one of the development priorities.
Polylactic acid (PLA), also known as polylactide, is formed by dehydration polymerization using lactic acid as a monomer. It uses renewable biomass such as corn, cassava and straw as raw materials, and its raw materials are widely available and renewable. PLA products can be decomposed into CO2 and water after composting to achieve circulation in nature.
Schematic diagram of PLA ecological cycle
Synthesis of PLA
There are two main methods for synthesizing PLA.
Ø One-step method: Direct synthesis of PLA by dehydration polycondensation of lactic acid
The method has the advantages of high monomer conversion rate, simple process, no purification by intermediates, and low cost, and the main problem is that the molecular weight and distribution of the product are difficult to control, and it is difficult to obtain a high molecular weight polymer. At present, Tongjieliang Company, which only uses the technology of Tongji University, adopts one-step method to prepare PLA.
Two-step method： The lactic acid is dehydrated to form an oligomer, and then depolymerized to form lactide, which is then subjected to ring-opening polymerization to obtain PLA.
Polylactic acid with adjustable molecular weight and microstructure can be obtained by this method, but the lactide ring-opening polymerization method is subjected to the step of purifying lactide, and the production process is long and the cost is high. At present, the production of PLA mainly adopts two-step method.
PLA itself is an aliphatic polyester, which has the basic characteristics of general-purpose polymer materials, has good mechanical processing properties, and is suitable for most synthetic plastic applications. Currently, it is mainly used for packaging materials, disposable tableware, fiber, 3D printing consumables, etc.
The world's major producers of PLA
Jiangxi Keyuan Bio-Material
NatureWorks has long occupied more than half of the market in the PLA industry; Total and Corbion have established a joint venture company, Total Corbion, to build 10,000-ton class PLA plant in Thailand in 2017, and officially put into operation in December 2018; HISUN expanded 10,000 tons of PLA in 2015, which ranked second in the world at that time. As PLA synthesis technology breaks foreign monopoly, China's PLA industry has entered the fast lane of development, and enterprises have begun to plan and build PLA projects on a scale of 10,000 tons or even 100,000 tons.
HISUN 50,000 tons PLA project initiated in 2015 is expected to release capacity in the fourth quarter of 2019, when HISUN will form a PLA production capacity of 65,000 tons/year; Jiangxi Keyuan Bio-Material completed the first phase of the 1,000-ton project in 2017, and the second phase 10,000-ton high-performance PLA and modified biodegradable material production line is under construction; In August 2018, the Jilin COFCO 10,000tons PLA Plant was successfully commissioned, plans to build a PLA project with an annual output of 100,000 tons.
In 2018, Jindan Bio-New Materials used the process technology of organic guanidine catalyzed directional polymerization to produce lactide and polylactic acid, which was initiated by Nanjing University. It has built a “10,000 tons/year L-lactide co-production of 1,000 tons/year PLA in Henan. The poly L-lactic acid continuous production plant is expected to expand to 10,000-150,000 tons in 2020.
Wuxi Nanda Green Environmentally Friendly Materials Technology Research Institute Co., Ltd. is using the original technology of “Bio-organic guanidine catalysis method for the synthesis of polylactic acid”. The “5000 ton/year poly L-lactic acid” continuous production device is being built, and the plan is, after the stable production, the design and construction of a 100,000-ton/year poly L-lactic acid continuous production plant will be carried out Immediately.
In the first half of 2018, CHTC ECOSPIRE built the international first production line of 10,000 tons of polylactic acid continuous polymerization and melting direct spinning fiber and products. Adopting the self-developed “polylactic acid melt direct spinning” technology, the energy cost can be reduced by 30%, and the overall saving can be 2100 yuan/ton.
In June 2018, BBCA Group's annual production of 100,000 tons of polylactic acid project was laid in Guzhen County, Anhui Province. At present, the whole industry chain processing line of corn-lactic acid-lactide-polylactic acid in Guzhen BBCA Bio-industry Base under construction. In March 2019, Tongliao Economic and Technological Development Zone signed a project of “Million-ton-class bio-new material polylactic acid” with BBCA Group. The total investment of the project is 12 billion yuan. It is planned to be constructed in three phases. The first phase of the project will invest 5 billion yuan, with an annual output of 300,000 tons of polylactic acid, it is planned to start construction in 2019 and be completed and put into operation in 2021.
Import and export
ASIACHEM compiled the import and export data of polylactic acid in the primary shape from January 2007 to March 2018. From 2007 to early 2008, China's polylactic acid was mainly used for export, and domestic demand was small. Export volume during 2008-2015 is relatively stable, domestic demand is growing steadily, makes imports are growing. During the period of 2015-2018, China's new/expanded polylactic acid projects have successively released production capacity, and the quality of products has been recognized by the international market, and the export volume has increased significantly.
The market for polylactic acid in China is growing steadily and has a tendency to accelerate growth. The export tax rebate rate for polylactic acid has been raised twice in 2018, from 5% to 10%, to a certain extent, allow enterprises to retain more profits, which is beneficial to polylactic acid enterprises to open up the international market.
The prospect of degradable plastics is unquestionable, but the current state policy on them is mostly concentrated on the technical research level. ASIACHEM believes that before the country has a clear incentive mechanism for the degradable plastics market, the Chinese polylactic acid industry should continuously reduce production costs and improve product competitiveness; strengthen upstream and downstream cooperation in the industrial chain, raw material manufacturers should pay close attention to the demand for downstream products, continuous improvement of material properties, market-oriented, expanding polylactic acid applications.
Degradable Plastic Technology and Market Forum 2019 will be held on April 24-25 in Kunming, Yunan, China. The upcoming conference will discuss degradable plastics policy development trends and market opportunities, production technology and cost reduction of eight major degradable plastics - PLA, PSM, Dibasic acid glycol copolyester (PBS/PBSA/PBAT), PHA, PCL, PGA, PVA and CO2 copolymers, diversification of degradable plastic raw materials and expansion of downstream applications, development and application of seawater degradable materials, etc.