**2. Material and method**

The methodology is based on the study of patent citation and is divided into two stages. In the first stage, patent documents were retrieved with bibliometric analysis carried out through the PatSeer® commercial patent database. It uses keywords such as: alcohol, bioalcohol, ethanol, bioethanol, saccharum, sugarcane, "sugar cane," bagasse, cellulose, biomass, lignocellulose and molasses. In the title and summary fields, it used the extend family filter. The study made use of Boolean operators "OR," "AND" and words truncated with asterisk (\*). We covered the period between 2000 and 2018, according to the priority date. All the retrieved documents were classified according to the keywords in the title, summary and claim fields, which resulted in the following categories: (i) pretreatment with acid and enzymatic hydrolysis, (ii) fermentation with yeast, bacteria or non-yeast fungus, (iii) distillation and (iv) sugarcane.

The second step was the data analysis per se, composed by:


**15**

**Figure 1.**

*Technological Trajectories Studies of Sugarcane Ethanol Production Using Patent Citation*

(4) Analysis of the profile of main authors of "breakthrough inventions";

(6) Analysis of citations of the downstream of breakthrough inventions.

As highlighted in the methodology section, the technology focus of the study

It is worth highlighting again that, on industrial levels, ethanol is considered to be a very relevant biofuel for producer countries, and which can be obtained from various primary and secondary (lignocellulosic biomass types) sources, such as:

i.through the hydrolysis of starch of cereal grains (corn, sorghum, wheat,

*Distribution over time of patent documents related to the production of sugarcane ethanol, highlighting 301 highly cited documents. Period: 2000–2018. N = 2023. Source: Compiled by the authors, PatSeer® database.*

is the production of ethanol from sugarcane in its various first-generation (ethanol) and second-generation (bioethanol) modalities. The search strategy used retrieved 223 patent documents in the 2000–2018 period according to the year of priority. Out of those 301 have more than five forward citations by patent family. An expressive range of data on first-generation (ethanol) and secondgeneration (bioethanol) production were observed positively that when stimulated and directed, there is a growing interest in the patent protection of the intellectual assets (in the form of patent depositories) coming from research and industrial

(5) Analysis of the interrelation of the technologies in the most cited "breakthrough documents" and the calculation of the technical impact index (TII) of the breakthrough inventions—the percent of patents in a period analyzed, which are in the most highly cited of all the breakthrough inventions. The expected value of the TII has been normalized to equal 1. "A TII below 1 indicates that patents are not especially highly cited" ([3], p. 272).

*DOI: http://dx.doi.org/10.5772/intechopen.88428*

**3. Results and discussion**

developments (**Figure 1**).

triticale, rye, malted barley, rice);

**3.1 Overview**

A ratio of >1 is good, a ratio of <1 is relatively low.

*Technological Trajectories Studies of Sugarcane Ethanol Production Using Patent Citation DOI: http://dx.doi.org/10.5772/intechopen.88428*

A ratio of >1 is good, a ratio of <1 is relatively low.

