Maleic Anhydride Production in China     

Li Zejiang, Shi Hui, the Research Institute of Industrial Economics of China National Chemical Information Center  
Maleic anhydride is the third most important acid anhydride worldwide today, only surpassed by phthalic anhydride and acetic anhydride. Maleic anhydride is mainly used in the production of unsaturated polyester resin (UPR), butanediol (BDO), fumaric acid, lube oil additives, agrochemicals, maleic acid, tetrahydrofuran (THF) and alkyd resins.
   China started research and development of maleic anhydride production technologies in 1958. With the rapid increase of demand for new pesticides with high potency and low toxicity, China's maleic anhydride production developed fast in the 1960s and the 1970s, with shortcomings such as poor design and substandard manufacture of reactors, poor properties of catalysts, excessive use and serious pollution. Several 10 000 t/a maleic anhydride units imported in the late 1980s helped domestic producers get onto a track of normal development. Today in China the technology for maleic anhydride production through benzene-based fixed-bed oxidization is already quite mature.
   China had 40 maleic anhydride producers in 2009 with combined maleic anhydride capacity of 1.124 million t/a. They produced 483 000 tons altogether. Most of them still use the benzene-based fixed-bed process. Five companies use the n-butane oxidization method to make maleic anhydride as of the end of 2009, including Dongying Victory Fine Chemical Co Ltd's 15 000 t/a fluidized-bed unit with imported ALMA technology, Karamay Jinyuan Fine Chemical Co Ltd's 20 000 t/a fixed-bed unit, CNPC Tuha Oilfield's 20 000 t/a fixed-bed unit, PetroChina Lanzhou Petrochemical Co Ltd's 20 000 t/a unit and Shanghai Huaheng Chemical Plant's 10 000 t/a unit.

Major Producers of Maleic Anhydride in China in 2009
Producer    Capacity (thousand t/a)
Taiyuan Qiaoyou Chemical Industrial Co Ltd     110
Tianjin Bohai Fine Chemical Co Ltd          100
Changzhou Yabang Chemical Co Ltd            80
Jiangyin Shunfei Fine Chemical Co Ltd       50
Xinjiang Gaoyi Coking Co Ltd                50
Shanxi Regent Taiming Chemical Co Ltd       45
Shanxi Hengqiang Chemical Co Ltd             40
Shanxi Hongdong Haoyi Coal Coking Co Ltd    40
Hongcheng Business Corp Ltd                  40
Zhe Jiang Huachen Energy Co Ltd              40
Others                                      529
Total                                       1 124
Source: CNCIC


   Many companies in China plan to construct new maleic anhydride units or expand their existing units. Some companies plan to use their current phthalic anhydride production units to produce maleic anhydride. Five companies are now constructing new maleic anhydride projects. Other 16 companies are doing primary surveys for new maleic anhydride project or have completed feasibility studies, involving total capacity of around 400 000 t/a altogether.

Import and export status

China's import volume of maleic anhydride reduced year by year between 2002 and 2007 while its export volume surged from 470 tons in 2002 to 88.2 thousand tons in 2007. China exported 73.9 thousand tons of maleic anhydride in 2008 and 42.7 thousand tons in 2009. Both the import and export volumes were small before 2003. The exports went down from the third quarter of 2007 after China reduced the export rebate rate for maleic anhydride from 13% to 5%, effective July 1st, 2007. Due to the financial crisis, imports and exports fell again in 2008 and 2009. Due to the surplus of maleic anhydride capacity, China needs to export more of it in the future.

China's Import and Export of Maleic Anhydride
   (thousand tons)
Year    Imports    Exports
2001    8.8     0.38
2002    5.6     0.47
2003    5.2     4.3
2004    5.1     11.4
2005    3.3     26.4
2006    3.7     58.9
2007    3.5     88.2
2008    1.2     73.9
2009    0.99    42.7
Source: CNCIC



Consumption in China

In China, maleic anhydride is mainly used to produce UPR, tartaric acid, coatings, BDO, THF, succinic acid and its anhydride, agrochemicals and lube oil additives.
   China consumed 441 thousand tons of maleic anhydride in 2009. The biggest use of maleic anhydride was making UPR, requiring 286 thousand tons, or 64.9% of the total; 44 000 tons (9.9%) went into the production tartaric acid; 28 thousand tons (6.3%) into coatings; 25 thousand tons (5.7%) into BDO and THF; 9.7 thousand tons (2.2%) into succinic acid and its anhydride; 5.7 thousand tons (1.3%) into agrochemicals; 5.7 thousand tons (1.3%) into lube oil additives; and 8.4% for other applications.

(1) UPR

UPR production is the most important use of maleic anhydride in China. UPR is one of the major thermosetting resins. Owing to its excellent performance in mechanics, electrics and chemical corrosion resistance, and ease of processing, it has extensive applications. China can produce more than 400 varieties of UPR today. UPR can be classified by application into general-purpose resin, chemical-resistant resin, flame-retarding resin, cast-molding resin, flexible resin, artificial marble, BMC/DMC resin, decorative resin, special resin, etc. In China, only 40% of UPR was used in the production of fiberglass-reinforced products and 60% was used in non-reinforced products. Among non-reinforced products incorporating UPR, handicrafts consumed 34%, buttons 24% and artificial marble 19%.
   China's UPR capacity was 700 000 t/a in 2002, the output was 600 000 tons, consuming 120 000 tons of maleic anhydride. In 2003 China produced more than 720 000 tons of UPR and consumed more than 850 000 tons itself, being the biggest UPR consumer in the world. China's UPR production sector has developed rapidly in recent years with an average annual growth of 27.6%, which was a big driver in the growth of maleic anhydride production. In 2003, 150 000 tons of maleic anhydride was consumed in making 720 000 tons of UPR. Sixty percent of that UPR was used to make fiberglass-reinforced products such as cooling towers, boats, chemical anticorrosion equipment, vehicle components, doors/windows, mobile homes, sanitary equipment, food processing equipment, recreation equipment and sports apparatuses, 40% was used to produce non-reinforced products such as polyboard, buttons, pseudo ivory and faux