A resolution for the specification of a new biofuel to be marketed in the country, renewable diesel, also known as green diesel or hydrotreated vegetable oil, is under Public Consultation at the National Agency of Petroleum, Natural Gas and Biofuels (ANP). HVO, in English). A public hearing on the topic will be held on Thursday (17/09), and the expectation is that a definition will occur by the end of 2020. The current Brazilian legislation (Law 11,097 of 2005) recognizes the use of renewable diesel as biodiesel in the matrix of biofuels in Brazil, however a resolution of the ANP (resolution 45/2014), still in force, determines that only ester-based biodiesel can be used to meet the portion of biofuels that must be added to the commercialized diesel at posts in Brazil. The adoption of renewable diesel in Brazil must follow the tested and successful form in Europe and the United States and is of fundamental importance for the development of biofuels in the country and for the control of vehicle emissions.

Ester-based biodiesel, currently used in Brazil, is produced through a process called transesterification - in which vegetable oil or animal fat reacts with methanol in the presence of catalysts, generating biodiesel.

Renewable diesel or HVO is also produced using vegetable oil or animal fats, however, using a more modern method, which consists of hydrotreating this renewable raw material, that is, its reaction with hydrogen with the use of specific catalysts. The process can take place in dedicated units or in conjunction with mineral diesel oil in processing units within oil refineries. The portion of renewable origin obtained in the product is chemically identical to mineral diesel oil (derived from petroleum), even bringing improvements in the final quality of diesel for the consumer.

The compulsory use of ester-based biodiesel was introduced in Brazil in January 2008 and has been gradually increasing in the country. However, as the increase in the proportion of biodiesel in diesel increases, the presence of glycerins, typical of this fuel, also grows, which has contributed to the occurrence of serious problems in pumps, injectors and filters in diesel vehicles. Another worrying problem is due to the metallic contaminants present and their incompatibility with the exhaust gas treatment catalysts of vehicles, making it impossible to use the technologies currently known to meet the emission requirements of compounds responsible for local pollution, such as nitrogen oxides and particulate material, which will come into force in 2022/2023, with the P8 phase of Proconve (Motor Vehicle Air Pollution Control Program), of Conama (National Council for the Environment).

Due to these limitations, in Europe, the maximum limit for ester-based biodiesel in road diesel oil is 7% by volume, while in the United States, this limit is 5%.

In this sense, renewable diesel, which has a paraffinic base, is chemically more stable than biodiesel and has a number of advantages. Renewable diesel does not contain glycerin or metallic contaminants; and its molecules are the same as those of mineral diesel oil (derived from petroleum). That is, it is a fuel that can be mixed with diesel oil without any restrictions. Renewable diesel also has greater storage stability, greater thermal stability and a high cetane number, a property that measures the ignition quality in diesel engines. In addition, studies by the Association of Biofuels Producers of Brazil (Aprobio) show that renewable diesel reduces about 15% of greenhouse gas emissions compared to biodiesel, for the same vegetable oil of origin, and 70% of emissions greenhouse gas emissions compared to mineral diesel oil (derived from petroleum).

Although not yet used in the mixture with diesel oil in Brazil, renewable diesel is already widely used in several European countries and in the United States. This is the renewable fuel whose use is growing the most in the world. The new biofuel will also be better suited to the most modern engine technologies being introduced in Brazil.

Petrobras conducted tests on an industrial scale for the production of renewable diesel, via co-processing with mineral diesel oil, in July, at the Presidente Getúlio Vargas Refinery (Repar), in Araucária, Paraná. The results show that the test was successful, with adequate performance of the catalysts and the refinery's operating units and with a high quality product, meeting all specifications.

Coprocessing production, widely used in other countries, has the main advantage of accelerating the insertion of renewable diesel in the energy matrix in an intelligent and competitive way, since it uses ready-made facilities in oil refineries. In addition, as renewable diesel is used in mixture with mineral diesel oil, a product is already prepared for use, without the need for additional mixing costs and independent certification of the products, which would impact the final cost. Once the insertion of renewable diesel in the Brazilian biofuel matrix is regulated, in the future, the implementation of exclusive units for the production of biofuel in pure form in Brazilian refineries will make sense.

It is important to highlight that, in order not to increase the price of fuel to the final consumer, renewable diesel must be adopted within the portion of biofuels already added to mineral diesel oil, since the production costs of renewable diesel are at the same levels as of biodiesel. This would make society in general, and especially consumers, able to enjoy the benefits of renewable diesel without feeling an impact on their pockets.

The price of ester-based biodiesel has risen significantly in recent months and competition between different types of biodiesel is the main tool to guarantee end-users fuel at attractive costs. This competition will only be possible with the expansion of the types of biofuels in the biodiesel mandate, as it will allow the development of production processes, new raw materials and cost reduction.

In view of the above, it is evident that the discussion on the topic is of paramount importance for Brazilian society, especially at this time when the ANP is conducting a public consultation on the subject. The adoption of renewable diesel following global standards of quality and efficiency, within the mandate of biodiesel, will certainly generate financial and quality benefits for the consumer and for the automotive segment, as it improves the performance and durability of the engines, as well as for the whole of society, with the reduction of greenhouse gas emissions, contributing to make Brazil prepared for new engine technologies and stricter rules for controlling vehicle emissions.