Review of Isoprene Demand

By Sun Yucheng, Fuyang Jinglue Chemical Technology Co., Ltd.

Isoprene is used mainly to produce high polymers such as styrene-isoprene-styrene block copolymer (SIS), isoprene rubber and butyl rubber. Small amounts are also used to produce fine chemicals such as vitamins, medicines, flavorings and epoxy hardeners.

Supply shortage in SIS market

The main SIS producers in China are Sinopec Baling Petrochemical Co., Ltd. (40 kt/a), Shandong Jusage Technology Co., Ltd. (30 kt/a) and TSRC (Nantong) Industrial Ltd. (30 kt/a). Also, Guangdong Zhonghe Chemical Plastic Co., Ltd. and Zhuhai Aosheng Polymer Material Co., Ltd. are small-scale producers. SIS is in short supply in the domestic market today. Materials such as SBS are substituted for SIS, while SIS is imported at a high price. Over 20 kt of SIS has been imported annually in recent years, mostly from TSRC of Taiwan, Shell and Dexco of the United States, JSR and Zeon of Japan, and Enichem of Italy.

Dilemma in isoprene rubber production

With the completion of several new production units in China, the world’s isoprene rubber capacity has increased steadily in recent years, reaching 963 kt/a in 2014, and Mainland China accounted for 28.56% of the world total. Table 1 shows the details.
The global natural rubber market has been oversupplied since 2013. It is expected that natural rubber prices will float at a low level and isoprene rubber prices will also remain low. The price of raw material isoprene, however, is still quite high. The operating rate of isoprene rubber units in China has not been high in recent years and dropped below 50% in 2015. Chinese firms still plan to construct several new isoprene rubber units (see Table 2).
With future rapid development of the auto industry, tire manufacture will remain the biggest use of isoprene rubber, estimated to take around 60% of total consumption. The consumption in making medical products will account for around 15%. Some large manufacturers of oil transmission pipelines are also making trial use of isoprene rubber to replace natural rubber. With the dissemination of isoprene rubber in making shoes, rubber tubing, rubber belts and machinery, it is expected that these sectors will consume 25% of China’s isoprene rubber in the future.

Butyl rubber sector

The butyl rubber sector has developed rapidly in recent years. The world’s butyl rubber capacity reached 1.593 million t/a in 2014, and output that year was around 1.20 million tons. But the output of butyl rubber in China is not high. The production of halogenated butyl rubber, in particular, started rather late here, output is low and domestic demand is satisfied mainly by imports. Eighty percent of butyl rubber used in China goes into tire tubes and inner liners. Some is used in medical rubber plugs. Car tire production in China will shift further toward radial, flattened and tubeless varieties; state policies encourage the development of radial tires. It is however expected that butyl rubber consumption will still grow quite rapidly.

Table 1  Isoprene rubber producers in China in 2014


Producer    Capacity (kt/a)    Variety
Luhua Hongjin Chemical (Maoming) Co., Ltd.    65    Rare earth series
LHIR-60,70,80,90
Qingdao Yikesi New Material Co., Ltd.    70    Rare earth series ?IR-70,80
Puyang Linshi Chemical New Material Co., Ltd.    5    Lithium series ?IR-563
Sinopec Beijing Yanshan Petrochemical Co., Ltd.    30    Rare earth series Nd-IR01,02
Shandong Shenchi Petrochemical Co., Ltd.     30    Rare earth series
Qingdao TPI New Material Co., Ltd.    15    Trans- series
Ningbo Jinhai Chenguang Chemical Co., Ltd.    30    Rare earth series
Dushanzi Tianli Industry Corporation    30    Rare earth series


Table 2  New isoprene rubber units planned in China

Company    Capacity (kt/a)    Time for startup
Shandong Hongyang Chemical Technology Co., Ltd.    30    2016
Ningbo Jinhai Deqi Chemical & Industry Co., Ltd.    30+60    2016 (first phase)
Lijin Petrochemical Plant Co., Ltd.    60    2016
Panjin Heyun New Material Co., Ltd.    50    2016
Shanxi Beifang Xingan Chemical Co., Ltd.    50    2017
Sinopec Fujian Refining & Chemical Co., Ltd.    30    2017


Demand potential in fine chemicals

Isoprene can be used as raw material to synthesize numerous fine chemicals such as linalool, citral, ionone, vitamin A and vitamin E. It can also be used to produce insecticides and flavorings.
China already hosts quite a few units producing pyrethrin insecticides through a reaction between isoprene and vinylidene chloride; the total capacity is around 4 kt/a. The technology for using isoprene to synthesize methyl heptenone, and subsequently to produce linalool, benefits from recent breakthroughs. Shanghai Petrochemical Co., Ltd. has developed a 2.5 kt/a complete process technology software package and constructed a commercial production unit. Batch production has started, making photoresist from isoprene for use in making integrated circuits. With the development of the pesticide and flavoring sectors in China, the annual demand for isoprene among makers of fine chemicals reached 8 kt in 2015 and will increase considerably in the next few years.