AC foamer starts diversification. (Market Report).

Rapid capacity expansion

China began production of the foaming agent AC (azodicarbonamide) in the early 1960s, and there were more than 30 producers in the 1990s. The country has already become the biggest foaming agent AC producer in the world today. Renovations and expansions were carried out by many producers as of 1992, and production has developed rapidly in recent years. The total capacity of 21 major domestic producers was expanded from 35 000 t/a to more than 60 000 t/a during the period between 1996 and 1998, a rise of 71%. The capacity in major producers such as Jiangxi Electrochemical Plant, Jiangsu Sopo Chemical Industrial Company and Ningxia Electrochemical Plant has reached over 10 000 t/a each. The capacity in Jiangsu Sopo Chemical Company increased by 20 000 t/a between 1999 and 2000. The capacity in Jiangxi Electrochemical Plant reached 30 000 t/a in 2000. Fuzhou No. 1 Chemical Plant, Zhejiang Juhua Group Corporation and Yibin Tianyuan Company, Ltd. have also expanded their capacity. The total capacity of foaming age nt AC in China was around 150 000 t/a at the end of 2000.

The production cost for most producers is RMB9 300 - 11 000 per ton. It is lowest in Jiangsu Sopo Chemical Industrial Company, at RMB9 300 per ton. The selling price of the product is RMB15 000 - 16 000 per ton.

Constant technical modification

To reduce the production cost, most domestic producers no longer use hydrazine hydrate as raw material. They have changed to using urea water solution to react with sodium hypochlorite and caustic soda in the presence of a catalyst. After the separation of soda ash through freezing, crude hydrazine hydrate solution (containing 4 - 4.5% hydrazine) is processed into biurea through the acid or weak alkali process.

In recent years the product quality has been much improved. Many modifications have also been made to production and equipment.

(1) Advanced equipment is used. Equipment for sodium hypochlorite production becomes large-sized and is in continuous production. Condensers and oxidizers are also large-sized. Intermittent drying is changed to continuous drying.

(2) Process control parameters in the hydrazine hydrate synthesis section and the oxidization section are optimized. The yield in various sections is increased and the material consumption and the cost are reduced.

(3) Byproducts are recovered for reuse.

Research has been conducted in recent years to replace chlorine with hydrogen peroxide as oxidizer. Qingdao Chemical Plant constructed a 2 000 t/a unit using hydrogen peroxide as oxidizer in 1992 in collaboration with Japan. The process has the advantages of no pollution, no byproducts, good product quality, high output, good gas generation volume and no explosion hazards. Research Institute of Chuanhua Group Corporation has already completed lab tests of the process.

Modified foaming agent AC is becoming focus

The consumption structure of foaming agent AC in China is 35% in PVC, 30% in PE, 10% in PP, 5% in rubber and 20% in other sectors (including export). The export amount is around 5 000 tons a year. The product is exported mainly to Southeast Asia, Japan, Korea, Russia and Hong Kong. With the development of the synthetic resin and rubber sectors and the implementation of the strategy "replacing timber with plastics", the output of foamed plastic products is increasing rapidly in China. The output of plastic products increased from 5.37 million tons to 8.0 million tons during the period between 1990 and 1998 and the demand for foaming agent AC also increased at an average annual growth rate of 20 - 25%.

In China foaming agent AC, for domestic sale or for export, is usually in the form of crude powder. Crude powder is seldom seen in overseas markets and products for sale are mostly in the complex form. Quite a few foreign companies buy crude powder from China and after the addition of additives, sell the complex in the market. China seldom sells foaming agent AC in complex form because domestic producers haven't paid enough attention to application research and quality standards have failed to reflect users requirements. Foreign producers have, however, placed equal importance on application and production and some of them have even conducted joint development of technologies with users.

With the development of science and technology, single-component foaming agent AC can no longer meet demands. Modified varieties have therefore come into being and have developed extremely rapidly. Various modifications have made foaming agent AC more diversified and specialized. Modification processes basically discharge no wastes, require small investment and produce considerable economic and social benefits. Several modified foaming agent AC units have been put on stream in Shanghai and Zhejiang in recent years. Modified AC-K developed in Shanghai Xiangyang Chemical Plant features a wide foaming range and easy process control and can increase the foaming rate by around 4.5% when used in PVC leather. The plant can already produce 6 product varieties. The modified foaming agent AC project undertaken by Zhejiang Juhua Technology Center has passed experts' appraisals organized by relevant departments. The company can already produce 3 product varieties. Producers having 2 or more than 2 product varieties inclu de Jiangsu Sopo Chemical Industrial Company (2), Cangzhou Chemical Industrial Group Corporation (2), Fuzhou No. 1 Chemical Plant (4) and Jiangxi Electrochemical Plant (2). Foaming agent AC in China is still not sufficiently diversified and falls far short of users' requirements.

Table 1

Major Foaming Agent AC Producers in China and Their Capacities (t/a)

Producer                              Capacity in 1998  Capacity in 2000

Hebei Cangzhou Industrial
 Group Corporation                          2 000             4 000
Fuzhou No. 1 Chemical Plant                 6 000            16 000
Jiangsu Sopo Chemical Industrial Co.       10 000            30 000
Mudanjiang Resin Plant                        800             1 000
Jiangxi Electrochemical Plant              10 000            30 000
Yibin Tianyuan Co., Ltd.                    2 000             7 000
Kaifeng Dongda Chemical
 Industrial Group Corporation               5 000             5 000
Shandong Hangtian Co., Ltd.                 4 000             5 000
Ningxia Electrochemical Plant               3 000            13 000
Zhejiang Juhua Electrochemical Plant        3 500            13 500

Total                                      66 700           145 900

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