Acetic Acid: Worries about Rapid Development

By Liu Liguo, An Dechun, Shandong Hualu Hengsheng chemical Co., Ltd.

Before 2010, domestic acetic acid capacity was insufficient, and much was imported. Since 2010, some large units have been put into operation. Capacity, output and demand are growing steadily. China is gradually becoming a net exporter of acetic acid, transitioning from being a net importer.
In 2015, capacity reached 8.25 million t/a, production reached 5.87 million tons and net exports reached 340 kt. By the end of 2016, capacity was 8.70 million t/a, production was 6.60 million tons and net exports amounted to 140 kt. The domestic capacity, production, import and export of acetic acid in recent years are shown in Table 1.
From the beginning of 2010, China was more than 100% self-sufficient with regard to acetic acid, and annual operating rates fluctuated irregularly between 57% and 74%. Excess capacity appeared. Acetic acid self-sufficiency and annual operating rates of recent years are shown in Table 2.

Downstream: acetic acid makers urgently need expansion in new areas

Acetic acid is a widely used basic chemical raw material. Downstream products are mainly traditional products – acetic esters, vinyl acetate, PTA, acetic anhydride, chloroacetic acid, diketene, etc. In addition, due to low acetic acid prices, production of ethanol by acetic acid is expected to rise rapidly.
In 2015, the manufacture of acetic esters, PTA and vinyl acetate consumed 78% of the acetic acid used in China. The overall consumption pattern is shown in Figure 1.
Except for ethanol producers, downstream users of acetic acid are generally overbuilt. Producing ethanol from acetic acid is the only area of new development. However, domestic R&D technology is still in transition to industrialization.
R&D about uses of acetic acid is simply inadequate, particularly in high-end industries. For example, the development and industrialization of ethylene-vinyl acetate copolymer (EVA resin and VAE emulsion), cellulose acetate and other high-end products are believed to pose important opportunities for developing the acetic acid chain.

Future: large-scale equipment

In the development of acetic acid technology, a variety of processes coexist, such as ethanol aerobic fermentation, oxidation of acetaldehyde (or ethylene as the starting material), oxidation of butane and naphtha and methanol carbonylation.
Due to economies of scale, low energy consumption and low cost, the methanol carbonylation process has become the mainstream technology of acetic acid production in recent years, both here and abroad. The development of large-scale equipment (single-line capacity of at least one million tons) can enhance benefits. At the same time, the development and application of new catalyst systems will further improve production efficiency and enhance overall competitiveness.                         
Table 1  China’s capacity, production, import & export of acetic acid, 2004-2015 (kt)
Year    Capacity (kt/a)    Production    Import volume    Export?volume
2004    1 500    1 116    526    17?
2005    2 000    1 370    547    35?
2006    2 360    1 600    707    29?
2007    3 800    2 193    501    138?
2008    4 300    2 575    305    24?
2009    5 250    2 969    298    65?
2010    5 900    3 839    59    217?
2011    6 700    4 248    18    667?
2012    7 500    4 303    23    332?
2013    7 570    4 300    18    183?
2014    8 000    5 352    17    181?
2015    8 250    5 872    53    393?


Table 2  China’s acetic acid self-sufficiency & average operating rates, 2004-2015

Year    Self-sufficiency     Average operating rate
2004    68.70%    74.40%
2005    72.81%    68.50%
2006    70.22%    67.80%
2007    85.79%    57.71%
2008    90.15%    59.88%
2009    92.71%    56.55%
2010    104.29%    65.07%
2011    118.04%    63.40%
2012    107.73%    57.37%
2013    103.99%    56.80%
2014    103.16%    66.90%
2015    106.15%    71.18%