Development Trends and Challenges in China's Calcium Carbide Industry   

By Zhang Yu, president of Calcium Carbide Industry Association of China

1. Review of the past five years

1) Capacity and output grew steadily

In recent years, with China's rapid economic development, and particularly the growth of domestic demand for PVC (polyvinyl chloride), PVA (polyvinyl alcohol) and other downstream products of calcium carbide, China's calcium carbide industry has been developing steadily. During 2006-2010, the nation's calcium carbide capacity grew about 20% annually on average. In 2010, the country's calcium carbide capacity reached 26 million t/a, and output grew to 14.62 million tons, substantially increasing by 174% and 64% over 2005, respectively. At present, the calcium carbide produced in China is basically for domestic uses, and only about 1% is exported. At the same time, almost none is imported.
   In the first nine months of 2011, China's calcium carbide output reached 13.571 million tons, up 25% year on year. Of that, 4.1439 million tons was from Inner Mongolia, up 25.3% year on year; 2.0458 million tons from Ningxia region, up 7.9% year on year; 2.0129 million tons from Xinjiang region, up 54.9% year on year; 928 400 tons from Shaanxi province, up 11.7% year on year; and 780 900 tons from Gansu province, up 13.3% year on year.

2) Industrial concentration increased significantly

Under the guidance of the national industrial policy, the average size of calcium carbide producers in China increased from less than 40 000 t/a in 2005 to 70 000 t/a in 2010; and the size of the largest calcium carbide producer also grew from 300 000 t/a in 2005 to 1.7 million t/a in 2010. By 2010, the number of producers with annual output over 100 000 tons had reached 54, and the combined output of the top ten producers reached 4.3206 tons, accounting for 29.55% of the national total, as shown in Table 1.

Table 1  Top ten producers of calcium carbide in China in 2010
Producer    Output (kt)
Xinjiang Tianye Group Co Ltd    1105
Yibin Tianyuan Co Ltd    506
Ningxia Western PVC Co Ltd    432
Xinfa Huaxing Industry Co Ltd    430
Erdos Power Metallurgy Co Ltd    415.6
Inner Mongolia Baiyanhu Chemical Co Ltd    322
Ningxia Dadi Metallurgical Chemical Co Ltd    312
Inner Mongolia Junzheng Chemical Co Ltd    299
CNSIC Jilantai Chlor-Alkali Chemical Co Ltd    258
Ningxia Jinyu Yuan Chemical Industry Group Co Ltd    241
Total    4320.6

3) Great advances in updating capacity

In order to respond proactively to the Chinese government's call, China's calcium carbide industry has eliminated a large number of outdated calcium carbide production facilities whose scale, energy consumption and environmental impact could not reach national standards. From 2006 to 2010, the industry eliminated 257 old calcium carbide furnaces, with a combined capacity of 3.05 million t/a, well beyond the target, 2 million t/a, for backward calcium carbide capacity elimination set by the Chinese government during the 11th Five-Year Plan period (2006-2010). 218 producers were involved in this elimination of substandard capacity.

4) Substantial decrease in energy consumption

With the maturity and promotion of large-scale closed calcium carbide furnace technology, its adoption in China's calcium carbide industry grew from less than 10% in 2005 to 40% in 2010. With the constant increase of automation and mechanization, the energy and material consumption rates of the industry have gradually declined. Currently, the production of 1t calcium carbide needs to consume 0.6 ton coke or 0.7 ton semi-coke, 0.96 ton lime, 28 kg electrode paste, 3250 kWh (closed furnace) or 3450 kWh (internal combustion furnace) electric power and 1t water. Not only was the consumption rate reined in, but the overall total of energy consumed was driven down 14.9%, from 1196.29 kg standard coal in 2005 down to 1018.11 kg standard coal in 2010. The calcium carbide industry still has a huge potential to save even more energy.

2. Development trends

1) Demand for calcium carbide keeps growing

China mainly uses calcium carbide to make PVC, accounting for more than 75% of the apparent consumption; about 10% is used in producing acetylene, which is used to cut metals; and the rest is used for the production of chloroprene rubber, polyvinyl alcohol, lime nitrogen and its derivatives. Therefore, domestic calcium carbide market trends depend mainly on the trends of the PVC industry. Experts estimate that by 2015, the calcium carbide-process PVC capacity in China will reach more than 20 million t/a. If capacity utilization is 70%, 19.5 million tons of calcium carbide will be needed annually. The manufacture of other downstream products, such as polyvinyl alcohol and lime nitrogen, will consume about 7 million tons of calcium carbide annually. Therefore, it is expected that by 2015, China's demand for calcium carbide will reach about 27 million tons a year.

2) Production is being transferred from southeastern coastal areas to western regions

Calcium carbide production is energy-intensive, relying heavily on coal and electricity. In the coastal areas of South and East China, raw material resources and energy - electric power in particular - are rather deficient. But in China's western regions, those resources and energy are both rather abundant. Thus, calcium carbide enterprises moving west has become an inevitable trend. With their advantages in energy and natural resources, the northwestern regions, such as Inner Mongolia, Ningxia, Xinjiang, Shaanxi and Gansu provinces, have become the preferred places for calcium carbide production. In 2010, the five provinces and regions had a calcium carbide output of 4.12 million tons, 2.37 million tons, 1.73 million tons, 1.05 million tons and 970 000 tons, respectively, and their combined output accounted for 70% of the national total. Northwest China has become an important commercial calcium carbide production base in China and even in the world.

3) Advanced furnaces replace outmoded types

Calcium carbide furnaces are divided into open, internal combustion and closed furnaces. China's open furnaces were all eliminated in 2006-2008, after which, internal combustion furnaces made up more than 90% of the nation's capacity. With the maturity and continued promotion and application of closed furnace technology, this proportion dropped to 60% in 2010.
   The two greatest features of the closed furnace are that the charging stock is isolated from the air, preventing it from combusting on the furnace surface, and the exhaust gas (mainly CO) is collected to be used as fuel for lime production or as a chemical raw material. Thus, the use of closed furnaces saves energy and reduces emissions significantly. And manufacture of the key equipment and technologies of closed furnaces has been fully localized. The main economic indicators of domestically made closed furnaces, such as energy consumption, raw material consumption and pollutant emissions, have reached the world's advanced levels. Therefore, the popularization of closed furnaces is very rapid in China. Its use in China's calcium carbide industry grew from 8% in 2006 to 40% in 2010.
   According to statistics, 300 full-closed calcium carbide furnaces, each over 40 000 kVA, will be put into operation in China before the end of 2012. They will have a combined calcium carbide capacity of 30 million t/a.

4) Enterprises extend toward downstream products, and develop circular economy