NOVELTY - Producing hydrogen from a hydrocarbon gas, comprises: contacting the hydrocarbon gas with a catalyst (1a) at elevated temperature to convert the hydrocarbon gas to hydrogen and solid carbon, where (1a) comprises a calcined iron-containing catalyst and/or a bimetallic nickel catalyst (a) supported on a substrate.    USE - The process is useful to: produce hydrogen from a hydrocarbon gas; produce graphitic particles; generate electricity from light hydrocarbons; and create a financial instrument tradable under a greenhouse gas emissions trading scheme (all claimed), where the financial instrument comprises a carbon credit, carbon offset and renewable energy certificate. The process is useful to produce onion-like graphitic particles, which are useful as solid state lubricants for wear prevention, anti-corrosion agents (preferably in high temperature applications (aerospace industry and solid fuel propellants), and as a substrate for lithium ion intercalation as found in lithium ion batteries.    ADVANTAGE - The process: converts light hydrocarbons to hydrogen substantially without co-production of carbon dioxide; produces hydrogen with a carbon product comprising graphitic particles, which can disassociate from the catalyst during the conversion process, thus significantly reduces caulking by avoiding build up of carbon product on the catalyst; provides a conversion efficiency of 30-75% or 50-70%; generates electricity substantially in the absence of carbon dioxide emissions, hence facilitates a relative reduction in greenhouse gas emissions compared to conventional electricity generation processes; and provides improved conversion efficiencies, even if the reaction is carried out under pressure. The conversion efficiencies are sustainable over greater than 50 hours with negligible depletion of (a) throughout the conversion process. In the process, an efficiency of the catalytic conversion is 0.3-0.95, where conversion efficiencies of greater than 0.4 are obtained.    DETAILED DESCRIPTION - Producing hydrogen from a hydrocarbon gas, comprises: contacting the hydrocarbon gas with a catalyst (1a) at elevated temperature to convert the hydrocarbon gas to hydrogen and solid carbon, where (1a) comprises a calcined iron (Fe)-containing catalyst and/or a bimetallic nickel catalyst of formula (MxNiy) (a) supported on a substrate.    M = transition metal or a lanthanide, preferably Mo or La;    x = 0.05-0.1; and    y = 0.01-0.05.    INDEPENDENT CLAIMS are also included for:    (1) a process for producing graphitic particles, comprising: contacting hydrocarbon gas with (1a) at elevated temperature to convert the hydrocarbon gas to hydrogen and graphitic particles;    (2) a process for generating electricity from light hydrocarbons substantially in the absence of carbon dioxide emission, comprising: contacting the hydrocarbon gas with (1a) at elevated temperature to convert the hydrocarbon gas to hydrogen and solid carbon; separating and recovering the hydrogen; using a first portion of recovered hydrogen in a fuel cell to generate electricity; and combusting a second portion of recovered hydrogen to generate elevated temperature;    (3) an apparatus for generating electricity from light hydrocarbons substantially in the absence of carbon dioxide emission, comprising: a catalytic reactor comprising (1a), where the catalytic reactor is configured to receive a hydrocarbon gas and contact the gas with (1a) under elevated temperature to convert the hydrocarbon gas to hydrogen and solid carbon; a separator to separate and recover hydrogen generated in the catalytic reactor; and a fuel cell configured to receive and use a first portion of recovered hydrogen to generate electricity, where the catalytic reactor is adapted to receive and combust a second portion of recovered hydrogen to generate elevated temperatures in it; and    (4) a method of creating a financial instrument tradable under a greenhouse gas emissions trading scheme (ETS), comprising: exploiting a process or an apparatus for generating electricity from light hydrocarbons substantially in the absence of carbon dioxide emission.