I'm getting a new Weber Grill this year and I decided to get it shortly before Pesach so that I can use it through the Yomtov. My normal charcoal is the the standard Kingsford original charcoal briquettes (the blue bag). I checked last year's Blumenkrantz (I don't have this year's yet) They say that since briquettes use a starch binder and it may be wheat based to use lump charcoal.
I contacted Kingsford and asked about the starch binder and if it was wheat based. They say the starch binder they use is corn based. Because of allergy issues I don't think they would lie about this.
Now, I'm not a posek, but I would think that a kitniyos based starch binder in charcoal briquettes would not be a problem on Pesach. The binder is specifically chosen to not have a taste or flavor.
I plan to use a lot of 2 zone and indirect cooking on the grill for which I prefer briquettes over lump charcoal. I suppose I'll go with lump anyway unless my Rav says otherwise.
What do you think?