Catalyst loading is another important parameter that can significantly affect the yields of degradation products. In this study, three different levels of catalyst load­ing, i. e., 5, 10, and 15 % were investigated for effects on the degradation of HDPE. In this study, the reaction time was fixed at 3 h for HZSM-5 (Si/Al = 80) catalyst. Meanwhile, in case of AlSBA-15 catalyst, initially, the reaction was carried out at a catalyst loading of 5 % for 4 h due to slower reaction to achieve significant level of degradation. As shown in Table 5, a catalyst loading at 10 % yielded the highest amount of light liquid while it produced the least amount of volatile gaseous product as compared to the other two catalysts loadings. The solid coke formation was found to be about 7 % for catalyst loadings of 5 and 10 %. Its yield was slightly higher with 15 % catalyst loading as 7.7 wt. % of the overall weight of residue was obtained.

The trace for waxy compound with 5 % catalyst loading amount was detected, but it was negligible and difficult to be accurately measured. The possible reasons of low conversion of degradation product to liquid were due to the concentration of 5 wt. % catalyst which was considered low to provide sufficient number of active sites for the degradation of large- to moderate-sized polymer chains. However, the optimum catalyst loading was found to be at 10 wt. %. It was further noted that larger amount of catalyst loading might promote faster reaction with higher forma­tion of coke in the residue of degradation products. This might be the reason for the catalyst inactivity throughout the degradation process (Ochoa et al. 1996).

In Fig. 9, the highest amount of liquid degradation product was obtained at 15 wt. % of catalyst loading (23.5 wt. % of the feed polyethylene). It also pro­duced moderate amount of volatile gaseous degradation products (52.2 wt. %) as compared to that obtained using HZSM-5(80). Furthermore, it could prove the theory that zeolitic catalysts such as HZSM-5 promote the production of

gaseous products during degradation of polyethylene. At the same time, it was not considered to be an ideal catalyst for the purpose of maximizing the degradation into liquid yield. However, one of the major disadvantages of using higher cata­lyst loading to increase the liquid product yield was that the formation of higher amount of solid coke in the residue might lead to the poor overall catalyst activity.

It was also observed that at 5 % of catalyst loading, no liquid or gaseous prod­ucts were successfully collected due to the formation of large amount of solid waxy compounds leading to a blockage at the reactor outlet. This was due to the rapid solidification of melted polyethylene degradation products when they were exposed to lower temperature at the reactor outlet. The small amount of catalyst loading was also unable to reduce the activation energy of the degradation process to enable the degradation mechanism to take place rapidly. However, significant formation of solid waxy compound was successfully inhibited at 10 wt. % of cata­lyst loading. Consequently, sufficient amount of liquid and gaseous degradation product was successfully collected. As illustrated in Fig. 9, the maximum liquid yield could be obtained at 15 % of catalyst loading. At the same time, less amount of solid waxy compound might be formed.

Fig. 10 Composition of gas products at 673 K using HZSM-5(80) catalyst over different catalyst loadings

Fig. 11 Composition of gas degradation products using various loadings of AlSBA-15 catalyst at 673 K

Figure 10 shows the data on the gaseous products using HZSM-5(80) catalyst. The highest composition was reported by C4 for 5 and 15 % of catalyst load­ings (27.8 and 33.6 %, respectively). Meanwhile for 10 % of catalyst loading, the highest proportion of C3 carbon chain was 38.4 %. At 5 % of catalyst loading, the amount of catalyst active site was deemed insufficient to cause significant deg­radation of polyethylene. Thus, higher amount of longer carbon chain molecules were produced as they could undergo further cracking reactions into smaller mol­ecules (Pierella et al. 2005). The results also indicated that increasing amount of catalyst would create better uniformity in the products distribution as seen in the case of 15 % of catalyst loading.

Likewise, data regarding catalyst loading and its effects on the degradation of HDPE to gaseous products using AlSBA-15 catalyst at 400 °C are shown in Fig. 11. The highest yield was recorded by the carbon chain of C4 with 15 % of catalyst loading (38.2 %). At 10 % of catalyst loading, its C3 carbon chain composition in the product was 42.1 %. It was also confirmed in earlier findings that the gas prod­uct was more concentrated in the middle of the carbon chain range such as C3 and

Fig. 12 Composition of liquid degradation products by various loadings of HZSM-5 (80) catalyst at 673 K

Fig. 13 Composition of liquid degradation products using various loadings of AlSBA-15 catalyst at 673 K

C4 (Hua et al. 2001). However, no product was detected for Ci products. Similar to earlier case, the use of higher catalyst loading produced more uniform products dis­tribution as in case of HZSM-5 catalyst. By comparing the degradation results using HZSM-5(80) and AlSBA-15 catalysts, it could be concluded that microporous cata­lyst HZSM-5(80) produced more shorter-chain carbon products. At the same time, mesoporous catalyst AlSBA-15 yielded more longer-chain carbon products.

Figure 12 shows the effect of catalyst loading on the distribution of degradation liquid products using HZSM-5(80) as catalyst at 400 °C. The highest composition was recorded with 5 % of catalyst loading to give a C21-C24 carbon chain range of 25.1 %. For the use of 10 and 15 % of catalyst loadings, the compositions of C8—C12 carbon chain range were 34.2 and 30.4 %, respectively. The longest carbon chain range C25+ was the minor product leftover after the degradation process. For this catalyst, it could also be seen that highest product yield was accu­mulated at the lighter end of the C8-C12 and C13-C16 carbon chain ranges.

By comparing to the earlier findings made using HZSM-5(80) catalyst (Koc and Bilgesu 2007), AlSBA-15 mesoporous catalyst showed a more non-uniform distribution (Fig. 13). The highest composition was recorded by a carbon chain

range of C8-C12, i. e., at 10 % catalyst loading (34.2 % yield) while at 15 % catalyst loading, 31.1 % yield of C13-C16 substances was obtained. Similarly, the heaviest carbon chain range, i. e., C25+ again recorded the smallest composition. The difference between the higher end and lower ends was bigger compare to the findings made using HZSM-5(80) microporous catalyst.

The objective of this research was of evaluating the concentration level of the bio­fuels industry market in Brazil from 2005 to 2012. Additionally, we calculated the concentration level for each Brazilian region, as well as the authorized productive capacity usage level and the impact of the industrial concentration in the average price and rentability of this industry.

For this research, we used the HHI and the CR to measure the evolution of industrial concentration level. The results point to a high concentration until 2006, when concentration of biodiesel industry started decreasing expressively, mak­ing the concentration in the industry atomistic, i. e., the industry has highly com­petitive features, considering the current concentration low level. These results reflect on the average price practiced by the 16 largest companies in the sector (that represent around 80 % of the volume produced in the country), and the other companies, where there was no statistically significant difference, where the aver­age prices practiced among both categories. This result can be explained by the hypothesis that companies would not have significant gains granted the sector’s low concentration, that prevents the significant reduction of auction prices, thus indicating some homogeneity of the prices practiced in the biodiesel industry in Brazil.

Besides the high competitiveness of this sector, it was possible to point out that most of the companies located in the south and central west regions, since these regions are known for their high soybean production, the main raw mate­rial used for biodiesel in Brazil. We also pointed out that the south region shows a high level of installed capacity usage level of its companies, pointing to a possible productive gap for this region, which represents 34 % of the national production.

On the other hand, we could see that the Brazilian ethanol industry concentra­tion is highly concentrated in the central-south region, where Sao Paulo (state) produces around 50 % of the Brazilian ethanol, considering that the concentration for ethanol distribution market has grown significantly in the last few years, which has implied better pricing opportunities and a better profitability for the sector, in detriment of consumers.

The conversion of biomass to biofuel varies substantially. First-generation bioethanol is produced through conventional fermentation of starch in the feedstock to convert it into glucose, which is then hydrolysed with the help of enzymes (Naik et al. 2010). The rest of the plant, as mentioned previously, is not employed in the production of bioethanol. It is therefore discarded, or used elsewhere, such as for fertilizer or as fuel in stationary energy provision. As a result, a substantial amount of the energy associated with cultivating, harvesting and processing is lost, with concomitant impacts on the environment, especially when carbon-based energy sources contrib­ute the bulk of the energy inputs, as they normally do so at present (Van der Laaka et al. 2007). A relatively high level of inefficiency and an arguably poor allocation of energy resources throughout the production process are therefore observable here.

First-generation biodiesel is produced from lipids, such as animal fats and vegetable oils, being reacted with an aliphatic alcohol, most often methanol or alcohol, in the presence of a homogeneous or heterogeneous catalyst (Naik et al. 2010). This process is generally referred to as transesterification. Some of the major drawbacks of this process include inefficient extraction of oil from seed, poisonous methanol run-off, high-reaction parameters and the complicated purifi­cation process that requires vast quantities of freshwater, which becomes contami­nated by small quantities of biodiesel. This necessitates water treatment to prevent these impurities entering ecosystems (Parida et al. 2011).

Some of the problems discussed above, however, may be addressed in the future through improvements in biotechnology. For example, genetic manipulation, together with biotechnological developments and improved horticultural practices, has the potential to greatly increase the amount of fermentable starches, sugars and oil found in crops destined for biofuel production (McLaren 2005; Davis et al. 2008). The use of sugar cane for biomass in Brazil has already shown itself as a leading light in first — generation bioethanol production, especially given that the fibre of the plant itself is used to produce the energy needed to produce the bioethanol (Larson 2008).

Second-generation biofuels are produced in a more sustainable way. There are two types of processes used to generate these fuels. The first, sometimes referred to as biochemical, uses enzymes to convert plant cellulose into bioethanol (Foyle et al. 2006; von Blottnitz and Curran 2007), with cellulosic or lignocellulosic (if the biomass contains lignin or woody material) bioethanol being the result. The second process, which is thermo-chemical in nature, is generally known as anhy­drous pyrolysis. This involves the chemical decomposition of biomass by heating it in an anaerobic environment, or without any reagents, so as to convert the plant material into liquid bio-oil or syngas. Liquid bio-oil cannot be used in conven­tional internal combustion engines, although it can be combusted to produce elec­tricity for stationary energy requirements (Chiaramonti and Tondi 2003). By way of contrast, fuels for conventional transport applications, including combustion in turbines, can be synthesized from synthesis gas (syngas) by subjecting them to heat treatment in the presence of air (Eggert et al. 2011). This is not a new pro­cess, having existed for decades, such as the gasification of fossil fuels to produce Fischer-Tropsch diesel, which, like Fischer-Tropsch gasoline, can also be cre­ated from second-generation biomass conversion (Larson 2008). In all these cases, high pressure and temperature requirements necessitate considerable energy inputs (Ragauskas et al. 2006).

It is obvious that a production process that uses all or almost all of the bio­mass is much more environmentally advantageous compared with first-generation processes. Furthermore, the choice of biomass for lignocellulosic bioethanol is much wider, which should allow a better matching of crop to local climatic con­ditions. For example, various types of hardy grasses requiring minimal care, and thus reduced energy inputs, can be used to produce the feedstock. Short rota­tion crops emerge as particularly useful for this purpose, including woody plants such as coppiced willow and poplar. Agricultural waste, such as sawdust, wood — chips or bagasse produced from sugar production, also looms as a clear possibil­ity for bioethanol production (Wright 2006). With anhydrous pyrolysis, any kind of organic waste material can be used. At present, second-generation production processes more or less only exist on a test or commercial demonstration scale, with almost all the commercial biofuel currently being used coming from first — generation processes (Eisentraut 2010). Stephen et al. (2011, p. 160) cite “large technological risk, large capital cost (driven by economies-of-scale), and the poor predicted economic performance of biorefineries” as the main barriers to their commercial uptake.

Overall, there is substantial debate about whether the production and applica­tions of fertilizers, pesticides and herbicides, together with energy inputs into the cultivation, harvesting, transport and production processes relating to the biomass and resultant biofuels themselves, in effect cancels out much of the energy derived from combusting biofuels for mobility-related purposes (Patzek et al. 2005). This is particularly so with regard to first-generation processes involving the waste of significant parts of edible food crops. Whatever the case, as Charles et al. (2007, p. 5743) concluded, “earlier biofuels have proved, at best, to be only marginally more environmentally sustainable and less polluting than fossil fuels, especially when one factors in resource requirements, in addition to production and refining costs”. Of course, improvement can clearly be expected as biomass cultivation and biofuel production methods are optimized over time.

The microalgae are photosynthetic organisms can grow in a wide variety of environments and conditions, including freshwater, salty, and brackish water (Benemann 2012). Their mechanism of photosynthesis is similar to higher plants, with the difference that the conversion of solar energy is generally more efficient because of their simplified cellular structure and more efficient access to water, CO2, and other nutrients.

Its uniqueness that separates them from other microorganisms is due to presence of chlo­rophyll and having photosynthetic ability in a single algal cell, therefore allowing easy operation for biomass generation and effective genetic and metabolic research in a much shorter time period than conventional plants (Singh and Sharma 2012).

In addition, the cultivation requirements are quite small, as most species only need water, CO2, and some essential nutrients such as nitrates, phosphates, and potas­sium, without needing the use of pesticides or fertilizers (Groom et al. 2008; Singh and Sharma 2012). Microalgae can produce lipids, proteins, and carbohydrates in large amounts over short periods of time. For these reasons, microalgae are capa­ble of producing 30 times as much oil per unit of land area compared to terrestrial oilseed (Sheehan et al. 1998). And these oil can be processed into both biofuels and valuable coproducts (Singh and Sharma 2012).

The microalgae cultivation can be heterotrophic or autotrophic. The hetero­trophic method is a biochemical conversion that relies on input feedstock derived from an upstream photosynthetic source. This approach uses closed bioreactor systems in a biochemical conversion process without light inputs. This dark fer­mentation process is based on the consumption of simple organic carbon com­pounds, such as sugars or acetate. The cultivation of algae using cellulosic sugars produced from wood and agricultural wastes or purpose-grown energy crops is an area of active research and development (Buford et al. 2012).

In the other hand, the autotrophic cultivation requires only inorganic com­pounds such as CO2, salts, and a source of light energy for their growth. This photosynthetic conversion involves two main methods: open ponds and closed photobioreactors (PBRs). The biomass produced in these autotrophic processes includes lipids that can be converted to fuels (Brennan and Owende 2010; Buford et al. 2012).

According to Benemann (2012), algae have been essentially produced in open ponds with the main strains currently being cultivated are Spirulina, Chlorella, Dunaliella, and Haematococcus. Most designs include mixing systems that use paddle wheels and carbonation techniques to supply and transfer CO2 (in-ground carbonation pit, bubble covers, and in-pound sumps1).

Microalgae are also grown in tanks and small-scale PBRs, in hundreds of dif­ferent systems around the world, producing from small amounts to huge sums of

http://www. powerplantccs. com/ccs/cap/fut/alg/alg_carbonation. html.

biomass annually. In this closed autotrophic approach, algae grow with sunlight or artificial lighting (Benemann 2012; Buford et al. 2012). Different types of PBRs have been designed and developed for cultivating algae that can be horizontal, vertical, tubular, flat, etc. (Benemann 2012; Singh and Sharma 2012). Each of these PBRs has their own advantages and disadvantages. Several studies are being developed which may overcome their limitations in the years to come (Singh and Sharma 2012).

In EU-27, the biomass consumption accounts approximately for 95.7 Mtoe, of which only a small part is used for biofuels, the rest for heat (40 Mtoe) and for electricity (48 Mtoe). If the renewable targets of the EU are to be met, an additional 120 Mtoe

45 40 35 30 25 20 15 10 5 0

of biomass needs to be produced by 2020, which would have to be obtained mainly from additional forest resources, but also new sources such as aquatic biomass, and eventually imports that will have to meet sustainability criteria.

In the European Union, the utilized agricultural area (UAA) is 178.44 million of hectares (Mha) which represents 41 % of the whole EU27 territorial area, while arable land represents almost one-quarter of European territory (24 %). In Europe, it is estimated that approximately 2.5 Mha of agricultural land is dedicated to bio­energy crops for liquid biofuels (Aebiom 2012), which represents about 1.4 % of the utilized agriculture area (UAA). ‘The European Commission (2011) calculated that 17.5 million ha of land would be required to reach the 10 % biofuels target, which would amount to about 10 % of the total utilized agricultural area (UAA) in EU27’ (Panoutsou et al. 2011: 3).

For this reason, the biodiesel companies of different member states have invested in third countries and in particular in Africa, to produce vegetable oil from Jatropha. But in order to be sustainable, the use of biomass for fuel and energy purposes must not jeopardize European and third countries’ ability to secure its people’s food supply, nor should it prevent achieving environmental pri­orities such as protecting forests, preventing soil degradation and keeping a good ecological status of waters.

The European agricultural land for biodiesel is used to produce oilseed crops (rape — seed, sunflowers, soybean) which are the major feedstock used to produce biodiesel (Fig. 6). Increased demand for oils from biodiesel producers has become over the past few years one of the driving forces of the global vegetable oil market. Any changes in biofuel policies in the European Union and in the USA as well as any advances being made on the next generations of biofuels is bound to alter the demand of vegetable oils for non-food purposes. Furthermore, in the coming years, national biofuel poli­cies may also increasingly affect international trade in vegetable oils used as biodiesel feedstock as well as trade in biodiesel itself (OECD-FAO 2012).

At global level, rapeseed oil, sunflower oil, soybean oil, and palm oil are the most produced vegetable oils. According to USDA data (Fig. 7), the global produc­tion of palm oil accounted for 39 % of all vegetable oils in 2011, followed by soy­bean oil (33 %), rapeseed oil (18 %), and sunflower oil (11 %). Figure 7 shows that

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the production of palm oil from 2000 to 2011 had a constant positive trend with an increase of 108 %. Remarkable results, in the same period, are also observed for rape — seed oil with an increase of 75 %, followed by sunflower (63 %) and soybean (59 %).

Although rapeseed oil and soybean oil are projected to remain the main feedstock, the use of palm oil is expected to more than double over the coming decade, with around 9 % of global palm oil production absorbed by the biofuel industry in 2021.

EU-27 and China are the world’s largest importers of vegetable oils, followed by India which shows an increase of 55 % respect to 2007. Despite Malaysia and Egypt being the countries with the highest increase of imports (81 and 73 %, respectively), their import levels are still low (USDA 2011). Indonesia, Malaysia, and Argentina have dominated the export market since 2007, even with Argentina’s decrease (-17 %) with respect to the previous years. Russia and Ucrania are the countries with the highest increase of exports (263 and 100 %, respectively), but their contri­bution to the export market remains marginal (USDA 2011).

Demand from the biodiesel industry is set to grow less than in the previous dec­ade when biofuel demand accelerated as policies were put in place. The use of vegetable oil for biodiesel is still expected to expand to 30 Mt, which corresponds to a 76 %increase over the 2009-2011 and raises the share of vegetable oil con­sumption used for world biodiesel production from 12 % in 2009-2011 to 16 % in 2021 (Fig. 8) (OECD-FAO 2012).

In the developed world, biodiesel demand should account for 73 % of total consumption growth. Biodiesel demand growth should continue to be lead by the European Union, where biofuel producers are expected to absorb 51 % of domes­tic vegetable oil up from 40 % in 2009-2011. Starting from a relatively small base, demand from the biodiesel industry is expected to almost double in the developing world, with growth in absolute terms not far behind the one projected in developed countries. Growth is expected in the traditional producers, Indonesia, Malaysia, and Argentina, but also in other parts of Asia (Thailand, India) and South America (Brazil, Colombia). Argentina further expands its export-oriented biodiesel indus­try, which, by 2021, could absorb 31 % of domestic vegetable oil output (OECD — FAO 2012).

Frequency indicates the degree of recurrence a transaction is performed (Williamson 1985), which according to Azevedo (2000) has a twofold role. First, when it is very frequent, the average fixed costs reduce, which are related to infor­mation collection and the preparation of a complex contract that sets restrictions to opportunism. Second, the higher the frequency, the less reasons for agents to impose losses on their partners, since an opportunistic attitude could lead to a disruption of the transaction and result in future earning losses from the transac­tion. In other words, for recurring transactions, the parties can create a reputation, which limits their interest in opportunistic attitudes for short-term gains, since according to the agents’ interpretation, gains tend to be higher in the long term (Azevedo 2000).

Repeating a transaction results in the parties getting to know each other through a reliable agreement stipulated around common interests. Even negotiations in the spot market have a cost reduction with recurring transactions due to a higher repu­tation (Farina et al. 1997). By establishing a reputation, trust on that agent also increases, which can lead to reducing safeguard clauses, hence reducing contrac­tual and monitoring costs (Bonfim 2011).

The governance structure regulated by the market itself is recommended for occasional or recurrent non-specific transactions, but in both cases, they are subject to standardization. Thus, the market can coordinate the relationships between the agents in a particular chain. The second one is characterized by a multilateral governance structure intended for occasional transactions, but it is characterized by mixed or highly specific investments. Therefore, this structure will inevitably be coordinated by contracts, that is, companies will try to elabo­rate individual or collective contracts for each type of transaction and for each type of agent. The third case is the one with a vertical governance structure, related to different types of recurring transactions and characterized by their high investment specificity, in other words, requiring more specific investments. Thus, this structure is characterized by incorporating a specific activity by the contracting party or even by all activities associated with the final product. This incorporation can be identified by a full or partial verticalization (Garcia and Romeiro 2009).

3.1 Uncertainty

The second key attribute discussed by Williamson (1996) is uncertainty. The impor­tance of considering this attribute results from the safeguards not addressed in the contracts. In an environment of uncertainty, agents are unable to predict all the events. Thus, the lower this prediction, the greater the gaps in the contracts and therefore the higher the chances of losses arising from the agents’ opportunistic behavior: In agri­culture, uncertainty may stem from various forms, such as natural disasters or unan­ticipated interventions in the food markets. Given this situation, contract renegotiation conflicts are plausible, which adds costs to the system as a whole (Azevedo 2000).

The most widely used analytical technologies for bioenergy chains are described

below:

• Titrimetry or volumetry determination of ions, especially by means of compl- exation reactions, neutralization or oxidation-reduction, resulting in the color change of the solution; this is the case of cation determination for feedstock and biofuels quality control (Artiga et al. 2005);

• Gravimetry determination of ions through complexation reactions, redox and precipitation, by means of drying and weighing the compound formed/ solid; this is the case of anion determination in effluent. For suspended sol­ids, it proceeds only to water evaporation and subsequent weighing of the solid

obtained. Gravimetry can be applied for feedstock and biofuels quality control (Seixo et al. 2004);

• Thermal analysis determining the water content and ash, loss of mass for con­stituents versus temperature, thermal stability, among other parameters asso­ciated with temperature effects on the material: thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC)—can be applied for pro­cesses, feedstock, and biofuels quality control (Kanaujia et al. 2013);

• Electrochemical the determination of metal oxidation states, quantification of organic and inorganic compounds, polar contaminants in effluents or products: potentiometry, voltammetry, polarography, and amperometry—can be applied for quality control of biofuels (Takeuchi 2007);

• Chromatography (liquid and gas) identification and quantification of organic compounds (volatile, semi-volatile, and nonvolatile) and inorganic, polar, and non­polar, such as sugars from sugarcane or starch, and its products of conversion pro­cesses: high performance liquid chromatography (HPLC) or ultra-high performance liquid chromatography (UPLC) with refractive index, ultraviolet-visible, diode array, fluorescence, mass spectrometry, and light scattering detectors; gas chroma­tography (CG) with flame ionization, thermal conductivity, electron conductivity, and mass spectrometry detectors—can be applied for feedstock, processes monitor­ing, and quality control of biofuels (Mischnick and Momcilovic 2010);

• Spectroscopy and spectrometry identification and quantification of organic and inorganic compounds, polar and nonpolar, such as metals and by-products in bio­fuel synthesis, by means of radiation interaction or radiation production: nuclear magnetic resonance, Fourier transform infrared, X-ray diffractometry and fluo­rescence, ultraviolet and visible spectrophotometry, atomic absorption spectrom­etry (AAS), optical emission spectrometry—can be applied for feedstock, process monitoring, and quality control of biofuels (Shuo and Aita 2013; Orts et al. 2008);

• Mass spectrometry identification and quantification of organic compounds, by means of molecular fragmentation—can be applied for process monitoring, to verify the product purity, and for metabolic engineering approaches of microor­ganisms (Orts et al. 2008; Jang et al. 2012);

• Microscopy (e. g., scanning electron microscopy, transmission electron micros­copy, and atomic force microscopy): observation of surface atomic composition and disposition of biomass components (morphology)—are frequently used for natural polymers and fibers (Hu 2008).

Table 6 presents some general uses of analytical techniques in chemical analysis of biomass for liquid biofuels production.

It is generally desirable to apply the highest possible number of techniques to obtain the greatest amount of information about a biomass. For example: Sugarcane could be analyzed by HPLC-refractive index detector to determine the sugar content, its molecular characteristics could be characterized by near-infra­red spectroscopy, and its energy content by differential scanning calorimetry. This same analytical approach could be applied to an oil crop for biodiesel production: GC-flame ionization detector for content of fat acids and esters in is grains; near­infrared spectroscopy for molecular characteristics, and differential scanning calo­rimetry for energy content.

Although several challenges remain in the trail toward algae biofuels commercialization and its adoption as a biofuel, as seen so far, an increasing number of companies and policy makers seem to believe the rewards outweigh the risks. Thus, the expectation pathway for algae-based biofuels remains uncertain.

Theoretically, microalgae have been shown to be a potential source to produce biodiesel because of their many advantages as a sustainable feedstock for biodiesel production compared to other feedstocks (Ahmad et al. 2011). Nevertheless, not only more innovations are still needed for the development of technologies that reduce costs while increasing the yields of production (Singh and Gu 2010), but it is also required a comprehensive set of policies to assist the development of micro­algae technology.

In the management area, it is extremely important in the early phases of this prom­ising industry, to deliberate new business models that look at the bioenergy poten­tial of algae through the transportation fuels market, as well as production of other higher-value products so as to make the economics practicable (Singh and Gu 2010).

2 Conclusion

The continued use of fossil fuels for energetic purposes is gradually becoming clearer to the society that is unsustainable. Innovative technologies and sources of energy must be developed to replace fossil fuels. In this context, biofuels play a vital role in meeting the energy needs of human beings. There is reason to believe they will continue to do so in the future albeit in a different manner. The basic economic motivation for biofuels is that they are a convenient, low-priced, domes­tically producible and a substitute for oil. However, alternative sources of biofuel derived from terrestrial crops such as sugarcane, soybeans, maize, and rapeseed inflict a lot of pressure on the global food markets, contribute to water scarcity, and precipitate the destruction of forests. Besides that, many countries cannot grow most of the terrestrial crops due to climate factors or lack of fertile cultiva­tion areas for energetic purposes. In this context, algal biofuels can really make a contribution for the future world sustainability.

In the presented chapter, it is clear that algae are now being intensively researched as a potential biofuel feedstock. In addition to their potentially high yields per unit land area, algae can grow in unsuitable land for agriculture, includ­ing industrial areas. Thus, their exploitation offers the possibility of a feedstock for producing biofuel that avoids damage to ecosystems and competition with agricul­ture associated with other biomass resources. Although many testing and start-up companies are in operation in several countries, cost information is scarce. Along the aforementioned literature review, a consensus was found that biofuels from algae are, in any case, still at the research and development stage and face numer­ous obstacles related to energy and water needs, and productivity.

Consequently, we revisited the recent developments in biofuel algae-based mar­kets and their technical issues, political standpoints, and environmental impacts. From a research and technology perspective, we stressed the importance of the US bioenergy policies and the European SET plan, as well as by the scenarios from IAE in 2010. These policies inform that several countries have introduced mandates and targets for biofuel expansion and, moreover, that production, international trade, and investment have increased sharply in the last few years.

The introduction of these new policies is essential for lowering the costs of algae biofuels, encourage investment, and develop greater diffusion of this emer­gent technology. Otherwise, in the lack of public policy, currently production costs will eventually remain too high to replace fossil fuels. In the same manner, it is expected that these policies will stimulate innovation to tackle some of the prob­lems in this emerging market.

The problems concerning large-scale production of biodiesel from algal farms on non­arable land include inconsistent and insufficient algal productivities, uncertain capital and operating costs, volatile market prices, and unknown levels of government support. Our survey permits to conclude that although intensive work is being done on many technolog­ical issues, economic studies and respective data are scattered, incomplete, and divergent.

With the onset of new policies, incentives, and massive investment in the pri­vate and public spheres, more researchers are forging new understanding in the science required to make algal biofuels economically feasible. In the present situ­ation, however, the technology to efficiently produce biodiesel from microalgae is not yet competitive. However, with policy support and incentives, we believe that the algal biofuel industry will continue to develop and assuming that this technology follows renewable energy cost trends, costs will decrease to even­tual economic viability. In parallel, processes must be developed to reduce costs and increase production. In this respect, the currently fast rate of development of algae biofuel technology and the actual rising of petroleum-based fuels prices are encouraging algae-based biofuels feasibility in the next few years.

Nevertheless, as shown in this chapter, we are witnessing a rise of companies’ strategies of entering new markets. Reports and news of new activities of algae — based companies are frequently on the news nowadays. These are signs that the uncertainties around the commercialization of this still not mature technology are not sufficient to hinder investment decisions.

Acknowledgments Lauro Andre Ribeiro and Patricia Pereira da Silva would like to acknowledge that this work has been partially supported by FCT under project grant PEst-C/EEI/ UI0308/2011 and from the Brazilian National Council for the Improvement of Higher Education (CAPES). This paper has been framed under the Energy for Sustainability Initiative of the University of Coimbra and supported by the R&D Project EMSURE Energy and Mobility for Sustainable Regions (CENTRO 07 0224 FEDER 002004).

Since 2008, the Brazilian ethanol market has shown a growing gap between the effective supply and the potential demand for this product. The ethanol demand is being vigorously stimulated by the flexible-fuel vehicles market, which totaled 20 million units in 2013 (ANFAVEA 2013); this total represents approximately 60 % of the vehicles in Brazil. Unfortunately, the capacity to produce ethanol in Brazil was not able to follow this growth. With the increase in ethanol demand and a corresponding supply reduction, it is essential to consider that there is an opti­mal point for the consumer’s decision about using ethanol or gasoline in vehicles. Currently, for Brazilian consumers using ethanol is only viable when the price of it is at least 70 % of the gasoline price, due to the differences in the efficiency of gasoline and ethanol, which is popularly called the 70 % ratio.

According to the data shown in Fig. 6, whereas in 2008 27.1 billion liters of ethanol were produced, in 2013 it is estimated that approximately 23.4 billion lit­ers will be produced, which represents a decrease of 13.6 %. In contrast, sugar production in 2008 was 31.5 million tons, but in 2013 its estimate is 38.3 million tons, which indicates an increase of 21.5 %.

2008 2009 2010 2011

Sugarcane —•— Sugar Ethanol production

Fig. 6 The production of sugarcane, ethanol, and sugar in Brazil from 2008 to 2012. Source UDOP (2013)

Because the production areas for sugarcane remain stable, the supply of ethanol in Brazil is mainly dependent on the price of sugar in the international market, which interferes with the production process (Fig. 6).

Unlike the ethanol supply, biodiesel has several raw material substitutes, as it is not dependent on only one source of feedstock. Among the sources used for production, we can mention beef and pork fat, used cooking oil, cottonseed oil, jatrophas, canolas, castor beans, and soybean oil. With the variety of options of raw material for biodiesel production, Brazil has anticipated an increase in the ratio of biodiesel in its diesel mix.

The demand for biodiesel is now fixed at 5 % in relation to the total diesel con­sumption, which was 2.7 million cubic meters in 2012. However, the installed industrial capacity for biodiesel production can produce double what is actually processed, or 500,000 m3 per month. Therefore, it is estimated that by 2015, bio­diesel consumption will increase by 10 % and the demand will expand by 50 %.

Figure 7 shows the occupancy rate data for biodiesel plants in Brazil. Note that because there is an idle installed capacity in the regulatory period and throughout the series, the actual production is below than 50 % processing capacity.

Nevertheless, one of the constraints of the biofuels supply in Brazil is the con­centration of production. According to ANP, it is estimated that the Brazilian mid­west region represents 43 % of the total production of biodiesel, and the southern region represents 34 % of the national production. Therefore, when this combined percentage (77 %) is analyzed, a concentration on production is found in these regions, whereas in Brazil’s north and northeast regions, there is a high rate of idleness of the biofuel facilities due to the climate and agriculture characteristics in those regions, as well as a disruption of the supply chain.

This pattern of disruptions has a direct impact on the final price of biodiesel, as the logistics support in the biofuel chain extends from the primary source of the agri­cultural inputs to the delivery of biofuel to distributors at the point of consumption or in ports. The price of transportation has a significant impact on the total price, and therefore, the locations farthest from the production center have higher sales prices.

Biodiesel prices are different in each Federal Brazilian state, which is especially due to the logistical costs for transferring it, primary and secondary warehousing costs, and final distribution costs. In this context, it is clear that there are different price rela­tionships between ethanol/gasoline and diesel (Goldemberg 2007) in different areas.

The domestic market for biodiesel is made through auctions. Therefore, a nearer biodiesel refinery for feedstock production decreases the price of the prod­uct and thereby increases the local competitiveness of biodiesel.

Government strategies to encourage a regular supply and increase the com­petitiveness of biodiesel in distant regions are conducted primarily through tax incentives. This policy mainly covers disadvantaged regions, as it seeks to include family farmers in biodiesel production.

Currently, ethanol production in the USA is stimulated by mandates set by the US EPA. Renewable Fuel Standard (RFS2) creates requirements which oblige fuel blenders to mix ethanol into fuel blends. In our analysis, first, we make a projec­tion of future volume of ethanol production with mandates in place until 2040. Then, we observe how these volumes change once market penetration costs are removed. This endeavor helps us in understanding how adjustments in current fuel distribution network and car fleet could influence total amount of ethanol produced and sold in the USA. Second, we look at the projected amount of ethanol pro­duced under situation with no mandates in place. That investigation provides us with projection of possible ethanol production should the US EPA decide to waive all renewable fuel mandates. Again, we look how these estimated amounts are impacted by removal of ethanol market penetration barriers.

Our next steps include examination of changes in volume of ethanol produced as a response to increasing CO2e prices. By doing this, we are able to see what level of CO2e price stimulates higher volumes of ethanol production, and we can verify at which CO2e price ethanol production reaches volumes mandated by the RFS2. We repeat the same exercise for two cases: first one with a market situation with no mandates in place but with market penetration barriers present, second one with no mandates and no market penetration barriers. In our analysis, we assume that the presence of carbon trading markets is a substitute for the EPA mandates because car­bon trading mechanism is supposed to provide incentives similar to standard quantity requirements. Therefore, we do not examine the impact of changes in CO2e prices on the volume of ethanol produced when the EPA mandates hold. At the end, we compare CO2e price effect on ethanol produced under two scenarios: with and without mar­ket penetration barriers in place in order to look at the magnitude of impact of mar­ket penetration removal on total ethanol produced in the USA. All in all, the outcomes of these scenarios provide enough information for decision makers to assess potential benefits which could arise from introduction of carbon pricing and trading mecha­nisms as well as positive environmental and economic consequences from removing market penetration barriers. Finally, we look at the impact of technological progress on volume of ethanol produced. We investigate how decrease in processing costs of cellu — losic ethanol influences quantity of crop and cellulosic ethanol produced at three points of time (i. e., 2020, 2030 and 2040). By doing this, we attempt to quantify the level of processing cost decrease necessary for ethanol production to become cost competitive.