First-generation biofuels use the edible parts of food plants as their carbon source feedstock. Due to this, the production of fuel from these crops effectively creates problems in regard to the global food production.
Second-generation biofuels use non-food substances as a feedstock carbon source. Examples include non-food plants, the inedible parts of food plants, and waste cooking fat. Unlike first-generation biofuels, they do not create problems in regard to the global food production.
The so-called "third-generation biofuels", similar to second-generation biofuels with an emphasize on the use of algae and cyanobacteria as a source of biofuel feedstocks, have an additional advantage as they take up a relatively small fraction of space when compared to first and second-generation biofuel sources, and may also help to reduce seawater eutrophication. They use algae to convert carbon dioxide into biomass.
Some fourth-generation technology pathways include pyrolysis, gasification, upgrading, solar-to-fuel, and genetic manipulation of organisms to secrete hydrocarbons. [4]
Hydrocarbon plants or petroleum plants are plants which produce terpenoids as secondary metabolites that can be converted to gasoline-like fuels. Latex-producing members of the Euphorbiaceae such as Euphorbia lathyris and E. tirucalli and members of Apocynaceae have been studied for their potential energy uses. [6] [7]
Some other companies making 4th generation biofuels are:
In July 2022, a Research Association of Biomass Innovation for Next Generation Automobile Fuels was established by six Japanese automotive companies. [9]