**1. Introduction**

The recent growing demand for energy alternatives to fossil fuels has been a reality shared by many countries in the first few decades of the twenty first century. Economic and environmental issues, population growth, industrial consumption, energy insecurity as well as existing conflicts around the use of raw materials for the production of food types used in the making of fuels, are some of the factors driving governments, universities and multinational corporations to broaden the scalability of their biofuels, such as ethanol, using renewable sources such as lignocellulosic types.

Ethanol can be produced from various raw materials, which can be classified into three categories: (a) simple sugar sources; (b) starch sources; and; (c) lignocellulosic material sources.

As to the technological profile of such categories, when presented in a timeline, they form the technology trajectories representing the production of ethanol, each one related to a specific technological paradigm. Therefore, one considers first generation ethanol ethical alcohol whose production requires raw materials that are rich in saccharosis (sugar cane juice, saccharine sorghum, beetroot, etc.) and/or rich in starch (sweet potato, wheat, potato, corn, cassava, etc.). Regarding second generation ethanol, it is made from biomass that is rich in lignocellulosic materials, such as wood, straw, stems and grass leaves. Finally, third generation ethanol comes from the processing of microalgae biomass after the extraction of lipidic materials (this production modality does not have an industrial representativity yet).

Taking into account this theoretical basis and considering the raw materials that are suitable for ethanol production, as well as the three modalities of the technological trajectory of ethanol production, we conclude that ethanol produced from sugarcane is currently the bioenergy production with the highest yield per unit and higher total energy balance, when we consider the proportion of energy in the final product (ethanol and mechanical energy, thermal and electric) and the fossil energy needed for its production. Besides, sugarcane ethanol offers the possibility of two technology trajectories that are almost consecutive (first- and secondgeneration productions with the use of sugar cane juice and bagasse).

In this context and in the light of the current technological scenario, this chapter develops an innovative approach to the production of ethanol that comes from sugarcane, combining concepts of patent heuristics with studies of technology trajectories, dependence and paradigms [1]. The study uses technology prospection techniques with analyses of "Breakthrough Inventions," also applying "Forward citations" for an analysis of future technology affinity. Finally, it seeks to obtain a consolidated profile to forward the technology trajectory of sugarcane-based ethanol production.

The piece is divided into three sections: methodology, results and final conclusions. Results and discussions are, in their turn, subdivided into five subsections: general panorama, breakthrough inventions—geographic and current owner distribution analysis, breakthrough inventions—technology analysis, breakthrough inventions—forward citation analysis and recent innovations and technological advances in ethanol production.
