zeolite+sources...

Folks, We are starting to use Zeolites, particularly ZSM5 for the removal of alkanes from petroleum fractions. The literature seems a bit scattered and non-descript on exactly which flavor people are using. Can someone send me a link to a distributor for the particular ZSM5 that they use? Also, does anyone have an active distributor for "silicalite" (formerly by Down Chemical) they can share? Thanks, Bob