Japan's Maruzen Petrochemical said on Monday it began restarting its 480,000 tons per year naphtha cracker in Chiba, east of Tokyo, earlier in the day, nearly a month after it was shut down following the magnitude 9.0 quake on March 11.
The restart means only two crackers remain shut due to the quake. They are operated by Mitsubishi Chemical Corp at its Kashima plant, northeast of Tokyo, and have a total capacity of 828,000 tpy.

Mitsubishi Chemical, a unit of Mitsubishi Chemical Holdings, said in late March that the restart of the crackers would take at least two months.

JX Nippon Oil & Energy Corp, an oil refining unit of JX Holdings, was also forced to shut a 404,000 tpy cracker  in Kawasaki after the quake, but it resumed operations on March 29.

Japan has a combined ethylene making capacity of 7.3 million tons a year, and nearly 17% of that capacity is currently off line due to the closure of the Kashima plants and a maintenance shutdown of Idemitsu Kosan Co's 374,000 tpy cracker at Chiba.