By Li Tie, Sinopec Tianjin Petrochemical Transport and Sales Centre

High utilization rate of C5 fraction in deep processing

China has a relatively high utilization rate of steam-cracked C5 fraction in the deep processing field, as reflected in the statistics for 2018, which shows 21 companies are involved in it, while only four are not. China’s effective cracked C5 capacities are listed in Table 1. The industrial-use cracked C5 mainly finds in C5 separation and resins industries, accounting for 95% of domestic cracked C5 consumption. Currently, C5 separation can be divided into rough separation and fine separation. The former is to produce C5 petroleum resin by de-cycling C5, and the latter is to separate isoprene, 1,3-pentadiene, dicyclopentadiene (DCPD) and C5 raffinate and pentadiene will be used for deep processing. 

   Table 1   China’s effective cracked C5 capacity in 2018Region CompanyEffective capacity (kt/a)

Significant increase in isoprene capacity

   In 2018, there were 11 manufacturers of industrial-use isoprene (polymer grade) in China (see Table 2 for details), and two crude isoprene producers. Domestic industrial-use isoprene (polymer grade) capacity increased by 22.47% YoY in 2018 to 312.2 kt/a, following the start-up of the 300 kt/a C5 separation unit at Huizhou Daya Bay Yikesi New Material Technical Co., Ltd. in May. However, domestic output only rose by 5.18% year on year in 2018 to 188.9 kt, due to limited growth in demand for the product.  

   Table 2   Chinese isoprene producers in 2018

   The breakdown of domestic isoprene (polymer grade) consumption in 2018 is as follows: SIS accounted for 61%, isoprene rubber, 26%, pesticide curing agents and butyl rubber, 13%. Downstream SIS producers generally posted a higher output in 2018, with over 10 000-ton increase seen at Baling Petrochemical and Ningbo Jinhai Chenguang. The isoprene rubber industry, however, was weak, as affected by the bearish natural rubber market and domestic isoprene rubber output decreased by around 20 000 tons YoY in 2018. 

   As we have ushered into the “oil refining era”, supply of steam cracking C5 is expected to double, bolstering the development of the equipped downstream C5 separation and resins plants. Hence, isoprene capacity will surge.  

1,3-Pentadiene can meet the needs of curing agents customers

   Domestic 1,3-pentadiene capacity expanded to 373 kt/a in 2018, up by 20.2% YoY (see details in Table 3), but its output dropped slightly to 216.4 kt, down by 2.3% YoY. The reduction is mainly because of relatively low content of 1,3-pentadiene in C5 fraction, caused by heavy maintenance schedules, limited increases in output and lighter feedstock. 

   Table 3   Chinese 1,3-pentadiene producers in 2018

   In China, 1,3-pentadiene is typically equipped with C5 petroleum resins plants. Currently, producers do not have such downstream units, including Shanghai Petrochemical, Yanshan Petrochemical, Fushun Yikesi, Beihua Luhua and Sinopec-SK Petrochemical are selling 1,3-pentadiene products into the commercial markets. In recent years, new C5 separation units are mostly used for fine separation, which yields premium C5 petroleum resins as compared to the decyclization process and the 1,3-pentadiene also meets the needs of some curing agents customers.  

   In 2018, 1,3-pentadiene was mainly used in C5 petroleum resins and curing agents sectors. Domestic output of C5 petroleum resins reached 322.7 kt, up by 9 200 tons YoY. Among them, the output of C5 petroleum resins for adhesives increased from the 2017 level, while that for road marking paints decreased. Demand from the curing agents field was largely stable. China’s 1,3-pentadiene import volume grew by 10.2 kt YoY. 

New DCPD plants mainly used for fine separation 

   In China, DCPD (polymer grade) plants are partially equipped with DCPD hydrogenated petroleum resin units and commercial products are generally used in the unsaturated polyester resins (UPR) sector. Domestic DCPD (polymer grade) capacity increased to 465 kt/a in 2018, up by 14.81% YoY (see Table 4). New DCPD plants are mostly for fine separation. Domestic DCPD output reached 257.4 kt in 2018, up by 3.71% YoY. 

   Table 4   Chinese DCPD producers in 2018

   The breakdown of domestic DCPD (polymer grade) consumption in 2018 is as follows: UPR accounted for 55.46%, DCPD hydrogenated petroleum resin, 33.95% and others, 10.59%. UPR remained the largest outlet of polymer grade DPCD. Stricter environmental protection restrictions and narrowed price gap with phthalic anhydride (PA) triggered a reduction in bicyclic modified unsaturated resins output. Domestic DCPD hydrogenated petroleum resins output increased by 26 kt YoY in 2018, following the new plant started up at Tianjin Luhua in October 2017.  

C5 petroleum resins mainly used in road marking paints

   Domestic C5 petroleum resins capacity increased to 517 kt/a in 2018 (see Table 5), because of a new 50 kt/a plant at Huizhou Daya Bay Yikesi. However, actual capacity only reached 482 kt/a as Shandong Landun had suspended production for many years, and Heze Hengda and Nantong Tiancai had not resumed operation since 2017. 

   Table 5   Chinese C5 petroleum resin producers in 2018

   Road marking paints are major applications for C5 petroleum resins. Domestic output for C5 petroleum resins used in road marking paints decreased by 4.49% YoY in 2018, but its share in downstream consumption increased by two percentage points. Demand from the rubber modification sector shrank either, due to the weakened rubber market. 

   Domestic C5 fraction supply is expected to double by 2022, as a growing number of naphtha crackers will be put on stream.