**2. A historic overview of biofuels use in Brazil**

such as sugar cane, corn, wheat, beet, and cassava. The vast majority of ethanol produced worldwide is from sugar cane, mainly in Brazil [3]. Biodiesel consists of long-chain fatty acids esters mixture, which is produced by transesterification reaction of triglycerides present in vegetable oils or animal fats with short-chain alcohols in the presence of a catalyst (normally a base such as sodium (NaOH) or potassium (KOH) hydroxide) [4]. Figure 1 shows transes‐

(normally NaOH or KOH)

Biodiesel use has been stimulated as an environmentally favorable alternative, since many studies have shown that biodiesel blends reduce particulate matter (PM), carbon monoxide (CO), and total unburned hydrocarbon (THC) emissions compared to diesel fuel [1, 5-8]. Biodiesel blends have been shown to reduce the overall life cycle emissions of CO2, when evaluated using a total carbon life cycle analysis [1, 9], although this can depend on a variety of factors, such as land use change and transportation [10, 11]. A drawback in using biodiesel blends, however, is the potential to increase nitrogen oxide (NOx) emissions compared to ultra-

The Brazilian specification for biofuel is similar to the European and American, with some flexibility to meet the characteristics of domestic raw materials. The Brazilian National Agency of Petroleum, Natural Gas and Biofuels (ANP) is the governmental agency that regulates fuels sold in Brazil through resolutions and technical specifications. The ANP resolution Nº 42 [13] provides a biodiesel specification (B100) according to the provisions contained in the Technical Regulation No. 4/2004. ANP Resolution Nº7 provides a specification for bioethanol (anhydrous and hydrous ethanol) according to the provisions contained in the Technical Regulation Nº 3/2011. Acceptable values or ranges for physical and chemical properties of both Brazilian biofuels, the respective analytical methods, and the importance of each analysis can be found

Biofuel analysis should be performed on a representative sample obtained according to the same methods described on ABNT NBR 14883 - Petroleum and petroleum products - Manual sampling or ASTM D 4057 - Practice for Sampling Petroleum and Liquid Petroleum Products

23

terification reactions of triglycerides for biodiesel production.

378 Biofuels - Status and Perspective

Figure 1 Transesterification reaction of triglycerides for biodiesel production.

**Figure 1.** Transesterification reaction of triglycerides for biodiesel production.

low sulfur diesel fuel [5-7, 9, 12].

on specialized literature [4, 14-16].

In 1975, the Brazilian National Alcohol Program (Programa Nacional do Álcool - PROAL‐ COOL) was created in Brazil to stimulate the use of domestic sources as a substitute for imported petroleum, and since then important changes occurred in the fuel composition used by motor vehicles in the country [19]. In 1979, 15% (v/v) of anhydrous ethanol started to be added to gasoline, reaching up to 22% (v/v) in the following years. The addition of 22% ethanol in gasoline was adopted by the Brazilian National Environment Council (CONAMA) [20] in 1990, on the recommendation of the energy sector. Production of ethanol-powered vehicles started in 1980.

The availability in the domestic market of hydrous ethanol and gasohol has brought benefits to the environment and to public health, highlighting the drastic reduction of toxic lead concentrations in the atmosphere. Ethanol acts as an anti-knock agent, replacing the lead-based additives, which have been completely removed from the national gasoline since 1991. In 1998, the Federal Government increased the content of anhydrous ethanol in gasoline to 24% through the Provisional Federal Law No. 1662-3 [21]. This increase did not result in significant changes in the vehicular emissions profile, since the vehicles manufactured in the country with more advanced technology, such as electronic fuel injection and oxygen sensors, were endowed with autocompensation system of the air/fuel ratio for variations of the ethanol content of that order. In 2006, the country's fuel blenders had to reduce ethanol content to 20% of its blended fuel because of ethanol shortages and returning to 25% soon after. In Brazil, gasoline volume sold was constant at around 2 × 107 m3 between 1996 and 2009 and then increased to 4 × 107 m3 in 2013 (Figure 2). During that same period, ethanol sold decreased from 1996 to 2003, restarted to increase, which peaked in 2009 (at 1.6 × 107 m3 ) and decreased to 1.2 × 106 m3 in 2013 [22].

**Figure 2.** Fuel consumption in Brazil. Data from the Brazilian National Agency of Petroleum, Natural Gas and Biofuels [22]. The biodiesel consumption was calculated considering its minimum content in diesel: 2% in 2008-2009 and 5% 2010-2013.

During all periods shown in Figure 2, diesel sales increased 2.2 times, from 2.6 × 107 m3 in 1991 to 5.8 × 107 m3 in 2013. Biodiesel started to be sold in 2008, and since then sales increased from 0.9 × 106 m3 to 2.9 × 106 m3 . In Brazil, the diesel composition has considerably changed in the last years. Diesel sold in Brazil, known as type B (containing biodiesel), the minimum biodiesel content was set to be 2% (v/v, B2) in 2008, 5% (v/v, B5) in 2010, 7% (v/v, B7) in 2014, and 10% (v/v, B10) after January, 2015. Details of the new regulations and for non-road applications are available at the ANP website [23].

The growth in the production of hydrous ethanol-fueled vehicles during the 1980s was very high due to the creation of the Brazilian National Alcohol Program, when about 94% of the new passenger vehicles were fueled by this biofuel, as can be seen in Figure 3. On the other hand, between the years 1989 and 1990, the surplus of gasoline associated with other factors resulted in a change from national alcohol overproduction to a deficit production situation [24]. In 1990, a combination of bad climatic conditions together with a rise in the international price of sugar forced the Brazilian Government to import alcohol (including methanol) for the first time to meet the national demand. Consumers had serious difficulties in getting alcohol to fill the tanks of their cars. In that year the production of ethanol-powered vehicles dropped from about 47% to about 11% of new vehicles produced. Due to shortage of anhydrous ethanol in Brazil, it was introduced, on an emergency basis, the mixture ethanol-gasoline-methanol (7%-60%-33% by volume, respectively), for use in ethanol-powered vehicles. After 2003, flex fuel vehicles were introduced into the Brazilian market. These vehicles are designed to be fueled with gasohol, ethanol, or any blend of both. These vehicles had become attractive because their owners no longer had to be concerned with the price and market availability of ethanol. Increases in the pump price of ethanol lead to large-scale consumption of gasohol, and then of ethanol when ethanol prices subsequently fell to a competitive level. These vehicles types use special electronic sensors and an on-board computer to recognize the fuel composi‐ tion and properly adjust the engine combustion parameters, without any interference from the driver. As shown in Figure 3, sales of these vehicles increased quickly in the Brazilian market. The vehicular industry in Brazil plays an important role on the economy, and has received governmental incentives. Currently, the government's role in ethanol fuels is much less and much different than in earlier times, and problems with the competition between the food and fuels sectors for sugarcane remain common.

**Figure 3.** New light-duty vehicles registered in Brazil by fuel type. Data from the Associação Nacional dos Fabricantes de Veículos Automotores (ANFAVEA).
