NOVELTY - Production of hydrogen, electricity and at least one hydroprocessed product from hydrocarbonaceous feedstock comprises subjecting the hydrocarbonaceous feedstock to a treatment with hydrogen in the presence of a supported catalyst. The hydrogen is produced partly from a fraction of the hydrotreated feedstock having a boiling point range different from the boiling point range of the fraction of the hydrocarbonaceous feedstock from which the hydroprocessed product will be produced, or from part of the hydroprocessed product.    USE - Hydrocarbon processing to produce hydrogen, electricity and at least one hydroprocessed product.    ADVANTAGE - When hydrogen is produced as the main product, carbon dioxide is produced at the same time in appreciable amounts which may be useful for commercial operations, e.g. for enhanced oil recovery or for heating purposes.    DETAILED DESCRIPTION - Production of hydrogen, electricity and at least one hydroprocessed product from hydrocarbonaceous feedstock comprising a fraction which has a boiling point range which is the same or higher than the boiling range of the hydroprocessed product to be produced, comprises subjecting the hydrocarbonaceous feedstock to a treatment with hydrogen in the presence of a supported catalyst. The hydrogen is produced partly from a fraction of the hydrotreated feedstock having a boiling point range different from the boiling point range of the fraction of the hydrocarbonaceous feedstock from which the hydroprocessed product will be produced, or from part of the hydroprocessed product. The hydroprocessed product is separated from hydrotreated feedstock when hydroprocessed product is to be recovered and part or all of the remaining hydrotreated feedstock and the hydroprocessed product if it is not to be recovered is subjected to a treatment to produce hydrogen. Part or all of the hydrogen not used for the treatment with hydrogen is subjected to a treatment to produce electricity, or part of the hydrotreated feedstock and the hydroprocessed product if it is not to be recovered is subjected to a treatment to produce electricity and at least part of the remainder is subjected to a treatment to produced hydrogen.