Data on surface area and porosity are presented in Table 1. It is clear that the HZSM-5 zeolite possessed typical textural properties of microporous materials. The pore volume and size of the catalyst HZSM-5(14) were almost half as com­pared to those of HZSM-5 (80). This showed that a reduction in the aluminum content of the HZSM-5 catalyst affected the material by increasing the poros­ity while simultaneously reduced the total surface area. However, in the case of SBA-15 catalyst (AlSBA-15), significantly larger surface area than HZSM-5 was observed. This confirmed the mesoporous nature of AlSBA-15 that exhibited wider mesopores as suggested by data in Table 1. These findings were in accord­ance with those reported by Kilos et al. (2005) who also observed the mesoporous nature of aluminum-functionalized SBA-15 catalyst.

Microalgae have been studied for many years for production of commodities and special human foods and animal feeds. Moreover, algae can generate a wide range of biofuels, including biohydrogen, methane, oils (triglycerides and hydrocarbons, con­vertible to biodiesel, jet fuels, etc.), and, to a lesser extent, bioethanol. Meanwhile, this products’ production involves different processes such as biochemical and ther­mochemical conversions or chemical separation or a direct combustion (Huesemann et al. 2010). Like a refinery, it is still possible to obtain other non-energy products in the cultivation of microalgae, such as cosmetics, animal feed, and nutraceuticals.

Subhadra and Edwards (2011) analyzed algal biorefinery-based integrated industrial sector that produces primary biofuel (biodiesel), coproducts (algal meal—AM), and omega-3 fatty acids (O3FA and glycerin). They demonstrated that biorefineries have a clear market for AM and O3FA up to a certain level; thereafter, diversification for other coproducts is desirable. However, coproduct market analysis and water footprint (WFP) of algal biorefineries need to be studied before large-scale deployment and adoption. In addition, Benemann (2012) argued that saying that “animal feeds could be readily coproduced with algae biofuels are incorrect”; because there are significant differences in the processes focus, quanti­ties production, volume and market values, comparing coproducts with biofuels. However, algal biofuel can be integrated with aquaculture to treat the wastes.

1.1 Chemicals and Catalysts

Microporous HZSM-5 (Si/Al = 80), HZSM-5 (Si/Al = 14) and mesoporous SBA-15 and AlSBA-15 catalysts, high-density polyethylene, nitrogen gas, cooling water, hydrochloric acid, N-hexane, triblock copolymer (TCP), tetraethylorthosilicate, and aluminum chloride were the chemicals or reagents, and they were used as received from respective suppliers.

1.2 Preparation of HDPE Sample

The material in pellet form was crushed into powder and then subsequently sieved using a sieving machine to obtain the desired particle size range. Sample of 60-150 mesh size was used in this study.

The commercial potential for microalgae represents a largely untapped resource, once there is a huge number of algae species. Some microalgae are mainly used to human nutrition, but are suitable for preparation of animal feed supplements. Like a biorefinary, it is possible to produce from biofuel and coproducts (espe­cially glycerin) to pigments and nutraceuticals.

The production of microalgae started in the early 1960s with the culture of Chlorella as a food additive and had expanded in others countries (Japan, USA, India, Israel, and Australia) until 1980s (Brennan and Owende 2010). The oil (tri­glycerides) extract from microalgae Chlorella, produced by dark fermentation, has high nutrient value and protein content, and their omega-3 fatty acid—DHA has been used as an ingredient in infant formulas (Brennan Owende 2010; Benemann 2012). D. salina is exploited for its beta-carotene content. Many strains of cyanobacteria (e. g., Spirulina) have been studied to “produce the neurotoxin b-N-methylamino — L-alanine (BMAA) that is linked to amyoptrophic lateral sclerosis-parkinsonism dementia complex, Lou Gehrig’s disease (ALS), and Alzheimer’s disease” (Brennan and Owende 2010, p. 572). The human consumption of microalgae biomass is restricted to very few species (Chlorella, Spirulina, and Dunaliella species domi­nate the market) due to the strict food safety regulations, commercial factors, market demand, and specific preparation. According to Subhadra and Edwards (2011),

a market survey of global algal producers indicated that more companies are planning to grow algae and extract the O3FA to market to consumers […] an immediate market of 0.2-0.4 million ton can be foreseen for algal based O3FA. A small portion can be further refined for marketing as human nutraceuticals and a significant portion for fortifying the AM produced as a co-product by algal biofuel refineries.

In the end of biodiesel production, it is possible to obtain a significant amount of glycerin that “there is a clear existing market from many industries such as paint and pharmaceuticals.” Some studies “have also shown that glycerin in turn can be effectively utilized to grow more algal biomass, another viable method of using glycerin in algal biofuel industry” (Subhadra and Edwards 2011).

Although the microalgae biomass is being produced essentially to human nutritional products, perhaps it is most attractive as animal feeds (Benemann 2012). Algae are the natural food source of aquaculture species such as mol — lusks, shrimps, and fish. In addition, it assists the stabilization, improvement, and enhancement of the immune systems of this cultures (Brennan and Owende 2010). They possess high protein rate (typical 50 %), high energy content (~20 MJ/kg), high concentrations of astaxanthin (used in salmon feed), and valuable carotenoids (e. g., lutein—used in chicken feed). Microalgae have also a long chain of omega-3 fatty acids to replace fish meal/oil (Benemann 2012).

SBA-15 molecular sieve was prepared according to a procedure reported by Ooi and Bhatia (2007). In 300 mL of deionized water and 40 mL of hydrochloric acid (37 %) for 1 h at 323 K, 9.8 g of triblock copolymer poly(ethylene oxide)- poly(propylene oxide)-poly(ethylene oxide) (average molecular weight = 5,800) was dissolved with stirring. Next, 21.7 g of tetraethylorthosilicate was added and stirred for another 10 min. The mixture was then heated at 333 K and then at 373 K for 24 h under stirring. The solid product obtained was filtered, dried at 100 °C, and then calcined in air at 500 °C. Four grams of SBA-15 was dispersed in 100 mL solution of AlCl3 and refluxed at 353 K with stirring for 2 h. The aluminum-containing mesoporous catalyst was then filtered, thoroughly washed with deionized water, dried at room temperature, and finally calcined at 823 K for 4 h.

1.3.1 Effect of Catalyst Loading

The data regarding effects of prepared catalysts at 623 K and 10 % loading on HDPE degradation into liquid, gas, residue, and waxy products yield are presented in Fig. 2 and Table 2. It is well noted that AlSBA-15 catalyst showed good degrada­tion activity to produce light hydrocarbon liquids while HZSM-5 catalysts having greater microporous surface area (Si/Al ratio 80 and 14) produced higher amounts of gaseous products. It is further explained that the primary cracking reactions might have occurred on the external surface which was in contact with the poly­mer. Meanwhile, the smaller fragments which were products of the initial reaction were mainly cracked within the microporous surface of the catalysts. However, the amount of coke was found to be lower as compared to the other degraded products.

In a previous study, Hwang et al. (2002) reported that the strong acid sites could accelerate cracking and deactivation reactions which resulted in the higher yield of coke as observed in case of prepared catalysts HZSM-5 and acid-treated SBA-15 in this study. Significant production of solid wax compounds using SBA-15 was also observed, and this could be due to insufficient number of acid sites in the material. Large wax formation after thermal degradation at the

Table 2 HDPE degradation-based product yield (%) by different catalysts

bottom of reactor could cause difficulty in the collection of other products such as liquid and gases. However, Mastral et al. (2006) reported that HZSM-5 pos­sessed an excellent stability that could effectively prevent the formation of coke due to its particular structure. Based on these findings, it could be concluded that the pore size, acidity, and shape are the important parameters that can affect the degradation activity of zeolitic catalysts. Similar findings have been reported by Hernandez et al. (2006) who observed that catalytic degradation using HZSM-5 yielded higher gas products during HDPE degradation. In another study con­ducted by Mastral et al. (2006) who carried out degradation process at different temperatures in a fluidized bed reactor, mesoporous materials such as SBA-15 did not show adequate degradation results. These observations confirmed our present findings as presented in Fig. 2. According to Urquieta et al. (2002), higher acidity in zeolitic catalysts might result in higher gaseous yield and a reduction in liquid yield. Again, the results confirmed findings made in this study.

The gas fraction compositions after HDPE degradation using different catalysts are shown in Fig. 3. It is noted that the catalysts HZSM-5(80) and HZSM-5 (14) exhibited the highest fraction for carbon chain C4 (37.1 and 30.2 %, respectively) and the lowest for carbon chain C5 (4.4 and 1.4 %, respectively). Meanwhile, SBA-15 and AlSBA-15 catalysts yielded the highest fraction for C3 (47.2 %) and C4 products. It should be noted that C1 products were not detected in the GC analysis. Both SBA-15 and AlSBA-15 catalysts produced more significant amount of C5 gaseous products (12.3 and 11.6 %, respectively). In the case of the mixture of HZSM-5 (80) and AlSBA-15 as catalyst, the gas carbon chain distribution was more uniform.

Findings and degradation trends using these catalysts for liquid product yield are shown in Fig. 4. The catalysts exhibited higher liquid products in favor of C8-Ci2, followed by Ci3-Ci6 and Ci7-C20. HZSM-5 (80) and HZSM-5(14) had

36.4 and 34.7 % liquid products, respectively, for C8-C12. Meanwhile, AlSBA-15 catalyst had the highest percentage of liquid products for C8-C12 (40.9 %). The pro­portion of liquid products for C13-C16 was also found to increase (37.3 %) when AlSBA-15 was used as catalyst instead of HZSM-5 catalysts as in the earlier case.

As stated before, like a refinery, it is still possible to obtain other products in the cultivation of microalgae, such as methane, biohydrogen, and ethanol. Some examples of these possibilities are presented as follows.

Methane. Since early studies on microalgae biofuels, the production of meth­ane biogas by anaerobic digestion of biomass was a main focus (Benemann 2012). This microbial conversion (of organic matter into biogas) produces a mix­ture of methane, CO2, water vapor, small amounts hydrogen sulfide, and some­times hydrogen (Gunaseelan 1997 in Huesemann et. al. 2010). This process has been successfully and economically viable despite the recalcitrance of some algal species to biodegradation and inhibition of the conversion process by ammo­nia released from the biomass. (Benemann 2012; Huesemann et al. 2010). For Huesemann et al. (2010),

Methane generation by anaerobic digestion can be considered to be the default energy conversion process for microalgal biomass, including algal biomass produced during wastewater treatment and for the conversion of residuals remaining after oil extraction or fermentation to produce more valuable liquid fuels.

Hydrogen. There are three main processes to produce hydrogen from microalgae: dark fermentation; photo-fermentation, and biophotolysis. The first involves anaer­obic conversion of reduced substrates from algae, such as starch, glycogen, or glycerol into hydrogen, solvents, and mixed acids. The second, these organic acids “can be converted into hydrogen using nitrogen-fixing photosynthetic bacteria in a process called photofermentation.” The latter, a biophotolysis process uses micro­algae to catalyze the conversion of solar energy and water into hydrogen fuel, with oxygen as a byproduct (Huesemann et al. 2010). Although these mechanisms were successfully proven in laboratory scale, they have not yet been developed as a practical commercial process to produce hydrogen from algae (Huesemann et al. 2010; Ferreira et al. 2013).

Ethanol. On the other hand, ethanol can be generated from two alternative processes: storage carbohydrates (fermented with yeast) and endogenous algal enzymes (Benemann 2012; Huesemann et al. 2010). The main process is “yeast fer­mentation of carbohydrate storage products, such as starch in green algae, glycogen in cyanobacteria, or even glycerol accumulated at high salinities by Dunaliella.” A self-fermentation by endogenous algal enzymes induced in the absence of oxy­gen has been reported for Chlamydomonas. Against the very low ethanol yield from both fermentation, several private companies are now reported to be developing ethanol fermentations.

Electricity and Gasification. The microalgae biomass can be dried and com­busted to generate electricity, but the drying process is fairly expensive even if solar drying is employed. The combustion and thermal process can destroy the nitrogen fertilizer content of the biomass and generate elevated emissions of NOx. In addition, the combustion process competes with coal and wood biomass that are cheaper than microalgae biomass (Huesemann et al. 2010). Although expen­sive, this can be a key factor for algae to achieve energetic balance and improve its sustainability. A lot of research is being carried in new and more effective drying techniques in order to reduce costs.

Oil. The significant quantities of neutral lipids, primarily as triacylglycerols, can be extracted from the biomass (green algae and diatoms) and converted into biodiesel or green diesel as substitutes for petroleum-derived transportation fuels. “Lipid biosynthesis is typically triggered under conditions when cellular growth is limited, such as by a nutrient deficiency, but metabolic energy supply via pho­tosynthesis is not” (Roessler 1990 in Huesemann et al. 2010). Further information on algae biodiesel is presented in the next chapter.

Wastewater Treatment. The nutrients for the cultivation of microalgae can be obtained from liquid-effluent wastewater (sewer); therefore, besides providing its growth environment, there is the potential possibility of waste effluents treatment (Cantrell et al. 2008). This could be explored by microalgae farms as a source of income in a way that they could provide the treatment of public wastewater and obtain the nutrients the algae need.

In particular, algae has a potential for recycling nutrients recovered from the wastewater (removing N and P), achieving higher level of treatment and gener­ating biomass. Compared to the conventional water treatment, these processes reduce overall greenhouse gas emissions, burning of digester gas derived from anaerobic digestion.

Biomitigation of CO2 emissions. In the majority of microalgae cultivation, carbon dioxide must be fed constantly during daylight hours. Algae biofuel pro­duction can potentially use CO2 in the majority of microalgae cultivation as car­bon dioxide must be fed constantly during daylight hours. Algae facilities can potentially use some of the carbon dioxide that is released in power plants by burning fossil fuels. This CO2 is often available at little or no cost (Chisti 2007). Thus, the fixation of the waste CO2 of other sorts of business could represent another source of income to the algae industry. This sort of fixation is already being made in some large algae companies in a trial basis though there is a lack of public data of the results yet. Although this is a very promising future possibility, and some species have proven capable of using the flue gas as nutrients, there are few species that survive at high concentrations of NOx and SOx present in these gases (Brown 1996). Public policies could also perform a great boost in this area depending on future CO2 cap and trade emissions or sustainability standards as shown in Chap. “Governance of Biodiesel Production Chain: An Analysis of Palm Oil Social Arrangements”.

in the Liquid Biofuels Industry

D. F. Kolling, V. F. Dalla Corte and C. A. O. Oliveira

Abstract Biofuels have emerged as a source of energy for many countries. Although the interest in developing this industrial sector might be sensitive to mar­ket issues, government policies can influence its supply and demand. This chapter provides a discussion on issues such as the supply, the demand, exports, imports, prices, and future perspectives of the global market of ethanol and biodiesel. We focus on Brazil and the USA, which are the leaders in these markets. We found evidence of a significant increase in the demand for biofuels in several countries, which contributes to their developing energy and environmental security and adds value to their agriculture sectors. Incentive programs for biofuels depend on gov­ernment policies. However, the production of biofuels differs in each country that we studied. The development of the biofuel chain is recent, and the supply depends on the whole structure of it and not exclusively on one institutional agent.

1 Introduction

Biofuel production started in the late nineteenth century when ethanol was pro­duced from corn and Rudolf Diesel’s first engine worked using peanut oil. Before 1940, biofuels were seen as viable fuels for transportation, but low fossil fuel [10] [11]

prices stopped investments and further development in biofuels. Interest in the production of these fuels re-emerged in the 1970s when Brazil and the USA began to produce ethanol on a commercial scale.

Sources of renewable energy are of great importance to national markets. The biomass and biofuel trade has been constantly growing, as it is driven by the increases in oil prices and by incentive policies for using biomass and biofuel to generate energy (Junginger et al. 2010). The dependence on oil and its derivatives has put the world’s economy, energy security, and environment at risk. In recent years, rapid growth in biofuel production has been observed around the world, and this growth has been supported by government policies.

The biofuel industry is a dynamic multi-sector that is involved in the system of fuel production and trade. The interest in developing this industrial sector is gen­erated from investor groups and is associated with economic, social, and politi­cal factors. In addition, biofuel production might be subject to market forces, as it depends on locations, the access to resources and the infrastructure for its genera­tion and distribution.

In addition to the economic aspects, the reduction of CO2 emissions has become an important driver of biofuel development. Interest in biofuels is rising because it represents an alternative fuel that shows superior environmental benefits to fossil fuels. Biofuels are also economically competitive and can be produce on a sufficient scale to impact energy demands considerably (Hill et al. 2006). This chapter provides a discussion on the relevant technical, economic, and administra­tive aspects of the global biofuel industry, and it describes initiatives in different countries.

Traditional biofuel technologies are presented in this chapter, including well — established processes for producing biofuels on a commercial scale. According to the International Energy Agency (IEA 2011), these biofuels are commonly referred to as first generation. The dynamic expansion of biofuel production pro­moted an increasing interest in economic studies that analyze the production, demand, supply, and trade of biofuels. These subjects will be discussed in this chapter.

At the current stage of PNPB, the institutional environment is crucial for the inclusion of oil palm family farmers in this production chain. Thus, the following is emphasized: implementing contracts with oil palm family farmers (a marginal portion of the business). There is tendency for the biodiesel plants located in the north—as well as those planning to initiate this business—to also verticalize their agricultural activities.

In the case presented in this chapter, the system imposes the debt discharge with the retention of the loan payment by the bank itself. Since the company is a kind of guarantor, by applying its own resources in the arrangement, it is consid­ered a sort of partner to the venture.

Given the attributes of the social transactions presented, the bonus system (premium payment for palm oil) is deemed as important to comply with the con­tractual agreement. This incentive encourages bilateral dependence, commitment, and credibility in the continuity of the relationship. The increased frequency of these transactions produces information between the parties, contributing to the agents’ reputation.

During the interviews, it became clear that the participation of the technical staff in the transaction strengthened the family farmers’ trust in the company, espe­cially because of their extensive knowledge of the region.

Thus, the technicians are key figures in the transaction as they are the interface between the purchasing department and the assurance of the supply quality.

The reputation and also the informal ties reinforce the different forms of coor­dination, which are important complementary elements in the transaction. Thus, the agents can build a reputation that increases the assurance that they will act within the expected ethical standards, which favors the investment of the parties involved in the transaction.

The social projects developed with palm were indicated by all respondents as a success case that should be replicated. The minimum quota of SCS to the north of the country is attractive, and, according to field research information, companies have already begun to perform their own mapping of family farmers that could produce palm oil in the Northern region. The goal is to plan an agricultural pro­duction that is in line with the needs foreseen of the processing plants.

There are several production routes for advanced liquid biofuels; however, none have yet reached the fully commercial stage. An overview of the biomass-derived biofuels production is shown in Fig. 1. Biomass is produced via photosynthesis, which is then processed either by biochemical or thermochemical routes to make liquid biofuels like bioalcohols, biodiesel, and biosynfuels. The biorefinery con­cept, usually based on either biochemical — or thermochemical routes, is exploited to produce biofuels from single or multiple feedstocks with value-added co­products and heat and power generation (IE A 2008). In fact, the production of high-value chemicals and bulk quantities of low-value biofuels maximizes the return from biomass feedstock, thereby improving the economic performance of advanced biofuels in a similar fashion as do the oil refineries nowadays. There is no single technology as of now that can use any feedstocks for biofuels process­ing; therefore, on-going research at laboratory, pilot, and demonstration plant is warranted. Such initiative will perfect the processes and technologies tailoring them to different feedstocks. At the moment, it is not clear, which feedstocks,

(Electricity)

Fig. 2 A network illustration to show the applications of products from thermochemical and biochemical conversion routes processes, and pathways will yield the minimal-cost biofuels or otherwise have the maximum potential for cost reductions over time. A network diagram to illustrate the application of products from biochemical and thermochemical routes using biomass feedstocks is shown in Fig. 2.