Low sulfur diesel fuel (S ≤ 500 ppm) has been available nationwide since 2004, followed by China III fuel (S ≤ 350 ppm) which became available nationwide in 2011.
While regulation GB 17691-2005 specifies emission limits for China III-V stages, in includes fuel specifications for the China III stage only. Faced with the lack of official fuel standards to ensure availability of ultra low sulfur fuels that are necessary to enable emission technologies at the China IV/V stages, the Ministry of Environmental Protection adopted regulation GWKB 1.2-2011 which regulates sulfur and polyaromatics as toxics. Selected specifications and availability status are shown in Table 1.
| China III | China IV | China V | |
|---|---|---|---|
| Sulfur content, mg/kg | ≤ 350 (GB 17691-2005) (GB 19147-2009) | ≤ 50 (GWKB 1.2-2011) (DB11/239-2007) | ≤ 10 (GWKB 1.2-2011) |
| Cetane number, min-max | 50-53 (GB 17691-2005) 45-49 (GB 19147-2009) | 47-51 (DB11/239-2007) | |
| Polyaromatic hydrocarbons, % (m/m) | 3-11 (GB 17691-2005) ≤ 11 (GB 19147-2009) (GWKB 1.2-2011) | ≤ 11 (DB11/239-2007) (GWKB 1.2-2011) | ≤ 11 (GWKB 1.2-2011) |
| Availability | 2011.07 (nationwide) | Beijing: 2008 Shanghai: 2009 Shenzen: 2009 | Beijing: 2012.06 |
High sulfur diesel fuels continue to be used for nonroad engines.