**2. Why has bio-ethanol become a successful alternative to partially replace petroleum fuels? A short history**

The beginning of the development of the ethanol fuel in Brazil is related to the petroleum shortage in Brazilian territory and the worldwide oil crisis. Brazil had few oil wells in 1970s, and the country was extremely vulnerable to international oil crisis. In 1973, during the first oil crisis, prices increased by 400%, which greatly affected the Brazilian economy in this way, and the Brazilian government began to seek an alternative to reduce its international dependence on oil. At that time, anhydrous ethanol, produced from sugarcane, had already been mixed to gasoline at a ratio of 5%, since 1931. In 1975, government created the Brazilian ethanol program, *Proálcool*, which involved many economical sectors to develop bio-ethanol as fuel to replace gasoline [2]. This program had massive governmental funds to develop feedstock and industry. In 1979, during the second oil crisis, Brazil presented the first ethanol fuel-powered car. At that time, Brazil had active state intervention over the price and the production of ethanol [3], which dictated the amount of sugar and ethanol to be produced. The ethanol price paid to the producers was a function of the sugar price. The price of ethanol and gasoline was established by the government at the fuel station. Therefore, the lower price of ethanol compared to gasoline led the population to choose ethanol-powered car instead of gasoline-powered one. As shown in **Figure 1**, the sales of ethanol cars skyrocketed, and in 1984, about 76% of the sales of cars using Otto cycle engines were ethanol fuel-based. At that time, most fuel stations in Brazil could offer ethanol as fuel.

At this point, it is worth defining "ethanol fuel" compared to anhydrous ethanol. "Ethanol fuel" is also known as "hydrous ethanol," and it is basically composed of ethanol (92.5–94.6%wt) and water. Ethanol fuel is used straightly into car engines without any blend. Anhydrous ethanol consists of at most 0.7% water by weight, and it has been used mixed with gasoline in different blend levels. **Figure 2** shows the fraction of anhydrous ethanol mixed with gasoline over the years. Anhydrous ethanol is also used as anti-knock agent, substituting the additive added to gasoline to avoid getting ignited early before spark occurs. Many countries still use methyl tert-butyl ether (MTBE) as a gasoline additive instead of ethanol, despite the environmental and health concerns. In the United States, MTBE has been replaced by corn ethanol since 2005 [4]. In Europe, part of the MTBE has been substituted by ethyl-tertiary-butyl-ether (ETBE) which is an additive obtained by the reaction of isobutene with ethanol [5]. In Europe, the amount of ETBE used instead of MTBE is dependent on the price of ethanol.

In 1985, after government system changed to democracy, the congress changed the rules of public policy concerning ethanol to include stakeholders on the government decision. As a result, the government moved away from the sector and the bio-ethanol fuel development faced more challenges to overcome. Firstly, the oil price decreased and ethanol became

**Figure 2.** Fraction of anhydrous ethanol added to gasoline. Source: MME Brazilian Ministry of Mines and Energy.

**Figure 1.** Fuel and anhydrous ethanol production; ethanol-powered car and flex fuel car sold in Brazil, and the price of the oil barrel. Source: [1] UNICA União da Indústria de Cana de Açúcar (2017); [2] ANFAVEA Associação Nacional dos

Assessment of Sugarcane-Based Ethanol Production http://dx.doi.org/10.5772/intechopen.78301 5

Fabricantes de Veículos; Automotores; [3] eia U. S. Energy Information Administration.

fuel, high-energy density, and relatively safe handling) made it an important substitute for liquid fuel from petroleum in the Brazilian energetic matrix. In fact, the world overwhelming dominance of gasoline, diesel, and jet fuel for transportation clearly shows the preference for liquid fuels due to their high-energy density. Except for the ethanol, most of the liquid fuels in the world are petroleum based. As petroleum is not renewable, in the long term, it must be substituted by other kind of energy. Aside from that, the use of fossil energy results in the releasing of greenhouse gas emission, which contributes for global warming. Hence, society in general is looking for alternatives to avoid global warming and thus replace petroleum. Biomass, like the sugarcane, clearly represents a sustainable and low-cost resource that can be converted into

liquid fuels on a large scale to have a meaningful impact on petroleum use.

**replace petroleum fuels? A short history**

4 Fuel Ethanol Production from Sugarcane

**2. Why has bio-ethanol become a successful alternative to partially** 

The beginning of the development of the ethanol fuel in Brazil is related to the petroleum shortage in Brazilian territory and the worldwide oil crisis. Brazil had few oil wells in 1970s, and the country was extremely vulnerable to international oil crisis. In 1973, during the first oil crisis, prices increased by 400%, which greatly affected the Brazilian economy in this way, and the Brazilian government began to seek an alternative to reduce its international dependence on oil. At that time, anhydrous ethanol, produced from sugarcane, had already been mixed to gasoline at a ratio of 5%, since 1931. In 1975, government created the Brazilian ethanol program, *Proálcool*, which involved many economical sectors to develop bio-ethanol as fuel to replace gasoline [2]. This program had massive governmental funds to develop feedstock and industry. In 1979, during the second oil crisis, Brazil presented the first ethanol fuel-powered car. At that time, Brazil had active state intervention over the price and the production of ethanol [3], which dictated the amount of sugar and ethanol to be produced. The ethanol price paid to the producers was a function of the sugar price. The price of ethanol and gasoline was established by the government at the fuel station. Therefore, the lower price of ethanol compared to gasoline led the population to choose ethanol-powered car instead of gasoline-powered one. As shown in **Figure 1**, the sales of ethanol cars skyrocketed, and in 1984, about 76% of the sales of cars using Otto cycle engines were ethanol fuel-based. At that time, most fuel stations in Brazil could offer ethanol as fuel.

At this point, it is worth defining "ethanol fuel" compared to anhydrous ethanol. "Ethanol fuel" is also known as "hydrous ethanol," and it is basically composed of ethanol (92.5–94.6%wt) and water. Ethanol fuel is used straightly into car engines without any blend. Anhydrous ethanol consists of at most 0.7% water by weight, and it has been used mixed with gasoline in different blend levels. **Figure 2** shows the fraction of anhydrous ethanol mixed with gasoline over the years. Anhydrous ethanol is also used as anti-knock agent, substituting the additive added to gasoline to avoid getting ignited early before spark occurs. Many countries still use methyl tert-butyl ether (MTBE) as a gasoline additive instead of ethanol, despite the environmental and health concerns. In the United States, MTBE has been replaced by corn ethanol since 2005 [4]. In Europe, part of the MTBE has been substituted by ethyl-tertiary-butyl-ether (ETBE) which is an additive obtained by the reaction of isobutene with ethanol [5]. In Europe,

the amount of ETBE used instead of MTBE is dependent on the price of ethanol.

**Figure 1.** Fuel and anhydrous ethanol production; ethanol-powered car and flex fuel car sold in Brazil, and the price of the oil barrel. Source: [1] UNICA União da Indústria de Cana de Açúcar (2017); [2] ANFAVEA Associação Nacional dos Fabricantes de Veículos; Automotores; [3] eia U. S. Energy Information Administration.

**Figure 2.** Fraction of anhydrous ethanol added to gasoline. Source: MME Brazilian Ministry of Mines and Energy.

In 1985, after government system changed to democracy, the congress changed the rules of public policy concerning ethanol to include stakeholders on the government decision. As a result, the government moved away from the sector and the bio-ethanol fuel development faced more challenges to overcome. Firstly, the oil price decreased and ethanol became economically noncompetitive compared to gasoline. Oil should cost more than U\$ 45.00/barrel in order to let sugarcane ethanol to be competitive [6]. Then, in 1990, the government suspended the quote requirement on the mill to produce ethanol [7, 8]. In 1996, the price control on the fuel sector ended [9]. In 1999, government completely deregulated the sugarcane sector [10]. As a result, the ethanol consumption stopped rising, and the ethanol fuel sector suffered without government regulations and incentives.

Nowadays, most of the cars sold in Brazil are flex fuel, and ethanol is easily found in every fuel station; thus, the customers are able to choose which fuel they want to use. It is worth noting that most Brazilians customers do not choose to use ethanol because it is environmentally friendly, but due to economic reasons. A survey carried out by the Brazilian Sugarcane Industry Association (UNICA) [14] shows that Brazilian consumers in general are not willing to pay more for ethanol than for gasoline even though the majority recognizes its environmental benefits. Even when ethanol has the same cost per driving kilometers (about 70% of the price of gasoline), 55% of the consumers choose to fuel the car with gasoline due to its higher autonomy. This behavior may be explained by "The Tragedy of the Commons" [15]

commons is less than the cost of not releasing it individually. Consequently, the majority of the consumers choose the fuel taking into account only their own benefits. This means that ethanol can survive as an alternative fuel only if it is economically competitive when com-

Environmental and social concerns also have a beneficial impact on the fuel ethanol program: pressures from nongovernmental organization (NGO) and the United Nations (UN) about reduction of greenhouse gas emissions (GHGs), and some civil society organizations about the social impact of ethanol supply chain on the society. One action taken to support the claim for reducing GHG was the creation of a tax on the nonrenewable fuel [16], which aims to support environmental programs and natural disasters caused by GHG. This is based on the "beneficiary pays principle," whereby when purchasing fossil fuel, the beneficiaries should pay the bear costs on the environment, which are believed to contribute to climate change. This seems suitable; however, it is very difficult to precisely evaluate the impact on the environment. Moreover, in 2018, the Brazilian government created the *RenovaBio* [17]—a national biofuel policy to set rules to allow sustainable expansion of the Brazilian biofuel market. In fact, nowadays, ethanol supply chain is responsible for 950,000 direct jobs and 70,000 farmers [18] in the country. For each direct job, 2.39 indirect ones [19] are estimated, resulting in over 2.4 million jobs. For this reason, the ethanol fuel environmental and social benefits cannot be

Besides its use as fuel, ethanol is used as a raw material to produce biopolyethylene. Polyethylene is one of the most popular plastics in the world. It is a polymer of ethylene and consists of a carbon backbone chain with pendant hydrogen atoms. Biopolyethylene is a polyethylene made from ethanol. The process consists in dehydrating ethanol to obtain ethylene prior to polymerization. The properties of this bioplastic are identical to the fossil-fuel based polymer. The main advantage of the polyethylene made from ethanol is that it captures and

Through this brief ethanol history, it is possible to infer that biofuel ethanol has undergone two different expansion phases: the first one is the *Proálcool* policy and the second one is the flex fuel car (concerning ethanol as liquid fuel). In these two expansion phases, the main claim was not the environmental one but an alternative fuel to the high price of petroleum. However, due to current global warming concerns, the world is looking for a renewable fuel

he discharges into the

7

Assessment of Sugarcane-Based Ethanol Production http://dx.doi.org/10.5772/intechopen.78301

in which the rational man finds that his share of the cost of the CO<sup>2</sup>

pared to gasoline or by law regulations.

left at the mercy of the variations in petroleum price.

from the atmosphere.

fixes CO<sup>2</sup>

Besides the end of the many subsidies, ethanol car technology had to deal with lack of consumer confidence, and so the sales of ethanol fuel-based car decreased. In 1984, ethanol car was still under development and, at that time, many problems were still unsolved such as the engine cold start. In 1989, due to the sugar price raising and the low oil price, sugarcane mills started to produce more sugar than ethanol. This resulted in a shortage of ethanol fuel, which led ethanol car users to stop using it. Besides, the ethanol engine, due to technical reasons, could not be easily converted to gasoline engine. For this reason, as shown in **Figure 1**, the ethanol car sales dropped from 76% to about 11% in Brazil, and 6 years later, no car manufacturer had ethanol fuel cars in its production lines. From 1995 to 2003, the ethanol demand was basically to supply fuel to the ethanol cars which had been sold before.

By 2003, due to the rising of oil price, ethanol fuel regained its competitiveness. At this time, as a consequence of the ethanol production/demand occurred after 1985, automakers started manufacturing cars using flex fuel technology and, as a result, the demand for ethanol as fuel rose again. Due to the flex technology, the customers can decide whether to fuel their cars with ethanol or gasoline. So, there were no more customers concerns about purchasing ethanol-powered cars. Hence, it became a self-regulating market; for instance, during the sugarcane crop season, the ethanol fuel price decreases, which motivates the preferential use of ethanol instead of gasoline. By analogy, when the stock of ethanol fuel is low, the price of ethanol would rise and it could be preferable for customers to use gasoline instead. This also corrected the problems related to the possibility of ethanol shortage due to climate changes that would affect the sugarcane crop and the amount of sugarcane diverted to produce sugar instead of ethanol. Consequently, the flex technology seems to have solved most of the problems related to the use of ethanol as fuel.

Flex fuel technology consists in adjusting the engine to operate using both kinds of fuel, ethanol or gasoline, and their blend in any concentration. In an Otto cycle engine, each fuel has different operation characteristics such as air/fuel ratio, compression ratio, and ignition timing [11]. The air/fuel ratio issue has been solved by measuring the oxygen content of the exhaust gas by the lambda sensor, which supplies the necessary information for optimal air/fuel mixture to the engine control unit. Electronic ignition timing controller adjusts the ignition time for maximum torque and fuel conversion efficiency [12]. However, the compression ratio, which is the ratio of the volume of the combustion chamber from its largest to its smallest capacity, cannot be easily changed in an engine. Ethanol engine requires a higher compression ratio than the gasoline one; thereby, the commercial flex fuel car has an intermediate compression ratio, which is intermediate to the ideal one for both fuels. Automakers have worked in variable compression ratio engines, which would result in an increment of engine efficiency [13].

Nowadays, most of the cars sold in Brazil are flex fuel, and ethanol is easily found in every fuel station; thus, the customers are able to choose which fuel they want to use. It is worth noting that most Brazilians customers do not choose to use ethanol because it is environmentally friendly, but due to economic reasons. A survey carried out by the Brazilian Sugarcane Industry Association (UNICA) [14] shows that Brazilian consumers in general are not willing to pay more for ethanol than for gasoline even though the majority recognizes its environmental benefits. Even when ethanol has the same cost per driving kilometers (about 70% of the price of gasoline), 55% of the consumers choose to fuel the car with gasoline due to its higher autonomy. This behavior may be explained by "The Tragedy of the Commons" [15] in which the rational man finds that his share of the cost of the CO<sup>2</sup> he discharges into the commons is less than the cost of not releasing it individually. Consequently, the majority of the consumers choose the fuel taking into account only their own benefits. This means that ethanol can survive as an alternative fuel only if it is economically competitive when compared to gasoline or by law regulations.

economically noncompetitive compared to gasoline. Oil should cost more than U\$ 45.00/barrel in order to let sugarcane ethanol to be competitive [6]. Then, in 1990, the government suspended the quote requirement on the mill to produce ethanol [7, 8]. In 1996, the price control on the fuel sector ended [9]. In 1999, government completely deregulated the sugarcane sector [10]. As a result, the ethanol consumption stopped rising, and the ethanol fuel sector suffered

Besides the end of the many subsidies, ethanol car technology had to deal with lack of consumer confidence, and so the sales of ethanol fuel-based car decreased. In 1984, ethanol car was still under development and, at that time, many problems were still unsolved such as the engine cold start. In 1989, due to the sugar price raising and the low oil price, sugarcane mills started to produce more sugar than ethanol. This resulted in a shortage of ethanol fuel, which led ethanol car users to stop using it. Besides, the ethanol engine, due to technical reasons, could not be easily converted to gasoline engine. For this reason, as shown in **Figure 1**, the ethanol car sales dropped from 76% to about 11% in Brazil, and 6 years later, no car manufacturer had ethanol fuel cars in its production lines. From 1995 to 2003, the ethanol demand was

By 2003, due to the rising of oil price, ethanol fuel regained its competitiveness. At this time, as a consequence of the ethanol production/demand occurred after 1985, automakers started manufacturing cars using flex fuel technology and, as a result, the demand for ethanol as fuel rose again. Due to the flex technology, the customers can decide whether to fuel their cars with ethanol or gasoline. So, there were no more customers concerns about purchasing ethanol-powered cars. Hence, it became a self-regulating market; for instance, during the sugarcane crop season, the ethanol fuel price decreases, which motivates the preferential use of ethanol instead of gasoline. By analogy, when the stock of ethanol fuel is low, the price of ethanol would rise and it could be preferable for customers to use gasoline instead. This also corrected the problems related to the possibility of ethanol shortage due to climate changes that would affect the sugarcane crop and the amount of sugarcane diverted to produce sugar instead of ethanol. Consequently, the flex technology seems to have solved most of the prob-

Flex fuel technology consists in adjusting the engine to operate using both kinds of fuel, ethanol or gasoline, and their blend in any concentration. In an Otto cycle engine, each fuel has different operation characteristics such as air/fuel ratio, compression ratio, and ignition timing [11]. The air/fuel ratio issue has been solved by measuring the oxygen content of the exhaust gas by the lambda sensor, which supplies the necessary information for optimal air/fuel mixture to the engine control unit. Electronic ignition timing controller adjusts the ignition time for maximum torque and fuel conversion efficiency [12]. However, the compression ratio, which is the ratio of the volume of the combustion chamber from its largest to its smallest capacity, cannot be easily changed in an engine. Ethanol engine requires a higher compression ratio than the gasoline one; thereby, the commercial flex fuel car has an intermediate compression ratio, which is intermediate to the ideal one for both fuels. Automakers have worked in variable compression ratio engines, which would result in an increment of engine efficiency [13].

basically to supply fuel to the ethanol cars which had been sold before.

without government regulations and incentives.

6 Fuel Ethanol Production from Sugarcane

lems related to the use of ethanol as fuel.

Environmental and social concerns also have a beneficial impact on the fuel ethanol program: pressures from nongovernmental organization (NGO) and the United Nations (UN) about reduction of greenhouse gas emissions (GHGs), and some civil society organizations about the social impact of ethanol supply chain on the society. One action taken to support the claim for reducing GHG was the creation of a tax on the nonrenewable fuel [16], which aims to support environmental programs and natural disasters caused by GHG. This is based on the "beneficiary pays principle," whereby when purchasing fossil fuel, the beneficiaries should pay the bear costs on the environment, which are believed to contribute to climate change. This seems suitable; however, it is very difficult to precisely evaluate the impact on the environment. Moreover, in 2018, the Brazilian government created the *RenovaBio* [17]—a national biofuel policy to set rules to allow sustainable expansion of the Brazilian biofuel market. In fact, nowadays, ethanol supply chain is responsible for 950,000 direct jobs and 70,000 farmers [18] in the country. For each direct job, 2.39 indirect ones [19] are estimated, resulting in over 2.4 million jobs. For this reason, the ethanol fuel environmental and social benefits cannot be left at the mercy of the variations in petroleum price.

Besides its use as fuel, ethanol is used as a raw material to produce biopolyethylene. Polyethylene is one of the most popular plastics in the world. It is a polymer of ethylene and consists of a carbon backbone chain with pendant hydrogen atoms. Biopolyethylene is a polyethylene made from ethanol. The process consists in dehydrating ethanol to obtain ethylene prior to polymerization. The properties of this bioplastic are identical to the fossil-fuel based polymer. The main advantage of the polyethylene made from ethanol is that it captures and fixes CO<sup>2</sup> from the atmosphere.

Through this brief ethanol history, it is possible to infer that biofuel ethanol has undergone two different expansion phases: the first one is the *Proálcool* policy and the second one is the flex fuel car (concerning ethanol as liquid fuel). In these two expansion phases, the main claim was not the environmental one but an alternative fuel to the high price of petroleum. However, due to current global warming concerns, the world is looking for a renewable fuel to replace petroleum and reduce emissions. A number of alternatives are under development, and the question that arises is if the bio-ethanol is going to be "the fuel." In case of a positive answer, one may expect a new expansion phase in the ethanol production sector. Further, in this new expansion phase, not only an alternative fuel is expected, but also a fully environmentally friendly one. Thus, the process might be highly efficient in all steps of the production chain, from the crop to its final use. Therefore, the efficiency of the production of ethanol and some opportunities to improve the efficiency will be addressed subsequently in this chapter.
