Complex sentence: Hydrogen cracking is sometimes said to pose a difficult engineering problem especially in the context of a hydrogen economy, however, commercially workable and safe technology exists globally in the hydrogen industry, which produces some 50 million metric tons per year.
Split into simpler sentences: Hydrogen cracking is sometimes said to pose a difficult engineering problem especially in the context of a hydrogen economy. However, commercially workable and safe technology exists globally in the hydrogen industry, which produces some 50 million metric tons per year.