In reformation, the alkanes become cycloalkanes or aromatic hydrocarbons, giving off hydrogen as a by-product.
ɪn ɹᵻfoːɹmˈeɪʃən, ðɪ ˈælkeɪnz bɪkˌʌm sˈaɪkloʊlkˌeɪnz ɔːɹ ɚɹoʊmˈæɾɪk hˈaɪdɹəkˌɑːɹbənz, ɡˈɪvɪŋ ˈɔf hˈaɪdɹədʒən æz ɐ baɪpɹˈɑːdʌkt.