[philonossis]

I am curious as to why desulfurizer would cause such an explosion.

I appears from this news clip, that desulfurizer was injected into an empty pipe, since the ship had already uploaded the oil.

any clarifications would be appreciated.

http://news.yahoo.com/s/ap/as_china_pipeline_explosion

"The explosion was caused when workers continued to inject desulfurizer into the pipeline after a tanker had finished unloading oil, according to a statement posted Friday on the website of the State Administration of Work Safety. A desulfurizer is a chemical substance used to remove high sulfur content from crude oil."