This video shows how to use the GET Search and Interactive Tools features of Knovel. For assistance with basic searching with Knovel contact a librarian.
After trying the resources above, you might also try keyword searching business databases like Business Source Complete . Use the the name of the chemical and the word "price" in the search. The full-text of some of the chemical industry trade publications can be searched in LexisNexis Academic ["Sources" along left column -> "Browse Sources" -> Country (All Countries) -> Topics (Chemicals) -> Industry & Markets -> Industry Trade Press -> then select and search the full-text of one or more of the 30 publications listed (e.g., Chemical News & Intelligence, Chemical Week, ICIS, etc.).
For sources of information & books on biomass & biofuels see the following LibGuide: Biofuels