Generation Biofuel Feedstock Research Articles

A New Approach for Synthesizing Fatty Acid Esters from Linoleic-Type Vegetable Oil

Countries around the world recognize the numerous social, economic and environmental advantages of promoting liquid biofuels. They invest in its development and introduce tax incentives for its manufacture and tariffs of production regulation. In most studies, the process of synthesizing fatty acid esters takes a long time from 1 to 8 h. In this work, the synthesis of fatty acid esters was carried out in the range of volumetric ratios of ethanol to linoleic type oil in order to increase the kinetics of the process. The main parameters of the synthesis were studied by use of magnetic stirred tank reactors in a parallel reactor system, H.E.L. The synthesis was carried out in the presence of a homogeneous alkaline catalyst. The volumetric ratio of ethanol to oil was maintained at 1:1, 2:1, 3:1, 4:1 and 5:1. The amount of catalyst added to the reaction mixture ranged from 0.25 to 2.5% by the weight of the reaction alcohol. The dryness of ethanol varied from 91 to 99%. Effective process conditions have been established to reduce the reaction time from 2.5 h to 5 min while maintaining a high degree of conversion. The results obtained during the study suggest the possibility of using a continuous reactor to produce fatty acid esters from linoleic raw materials containing up to 16% of free fatty acids. This also means the possibility of using second generation biofuel feedstock.

Heterogeneous Catalysis of Second Generation Oil for Biodiesel Production: A Review

AbstractThe demand for cleaner fuels has been on the rise lately, prompting researchers to explore alternative cleaner technologies to meet the growing demand. This has led to the introduction of renewable fuels such as bioethanol and biodiesel. Depending on the feedstock employed for production, renewable fuels can be divided into first, second, and third generation. Reliance on first generation biofuel feedstocks has led to inherent competition between foods versus fuels in the society in the last decade. Further technological prospects in research and development have provided insight into the use of second generation biofuel feed‐stocks from non‐edible agricultural waste products, energy crops, and crop residues. Zeolites and modified zeolites as heterogeneous catalysts have been highly prospective for the transesterification process of these oils. Modified zeolite can act as a bi‐functional catalyst because of its acidic and basic sites. Here, a review of transesterification reaction technology, zeolite and modified zeolite as a heterogeneous catalyst to generate biodiesel was discussed. Current status, challenges and future prospects are also discussed.

THIRD GENERATION BIODIESEL: A POTENTIAL SUSTAINABLE ENERGY SOURCE FROM MICROALGAE

Biofuel production from renewable sources is generally considered to be one of the most sustainable alternatives to fossil fuels, and a viable means of sustainability for the environment and the economy. Because of their rapid growth rate, CO2 fixation ability and high lipid production efficiency, microalgae are currently being promoted as an ideal third generation biofuel feedstock; they also do not compete with food or feed crops, and can be grown on non-arable soil. Biofuels can be generated in combination with flue gas CO2 mitigation, wastewater treatment and high value production. Seawater can be used to achieve microalgal farming employing microalgal organisms as the source. To be a realistic option, a biofuel must have few features such as net energy gain, eco-friendly, economically efficient and implementable in large volumes without affecting resources demand. In this study we present an overview of the use of microalgae for the production of biodiesel, including its cultivation, harvesting, and processing. Further it is suggested that biodiesel is an effective renewable substitute for petroleum diesel. KEYWORDS: Biodiesel, Biofuels, Carbon emission, Microalgae

Applications of microalgal and cyanobacterial biomass on a way to safe, cleaner and a sustainable environment

Abstract Algae (especially microalgae and cyanobacteria) are potentially diverse, ubiquitous, and dominant group of photosynthetic organisms in nature. The dominance and diversity of algae are commonly observed in small puddles, streams, river, to oceans and even in extreme habitats like cold springs to hot deserts, which makes them a prominent organism for various applications. The past decade has evidenced microalgal research in bioenergy production and other vital biomolecules with wide industrial applications. Further, the easy availability of microalgae and cyanobacteria makes them a suitable candidate for various biotechnological applications like food, feed, fodder, and fuel. Algae are grouped under the third generation biofuel feedstock offering numerous environmental benefits viz., efficient land usage, CO2 sequestration and utilization and most importantly resolving the food vs fuel feud. With this perspective, this review article aims to unravel the conventional and novel applications of microalgal and cyanobacterial biomass in various enterprises and also the recent trends in their exploitation. To understand the overall potential of microalgae, at inception, this review article has articulated a detailed account of the applicability of various algal biomasses for different biofuels such as bioethanol, biodiesel, and biohydrogen. As an environmental benefit, bioremediation of wastewater or nutrient removal from municipal and industrial sources, and pesticide removal using several microalgal strains has been critically appraised and presented comprehensively. Also, the enormous biodiversity and difference in the biochemical composition of microalgae make them stand as a promising source for biologically active compounds with high commercial value. In addition to energy products from algae, converting the biomasses into various industrially important co-products or high value products is an economically sound approach. At this juncture, extraction of secondary metabolites, carotenoids, phycobiliproteins, phytosterols and phenolic compounds from numerous microalgae and cyanobacteria has been discussed in detail. Overall, the present review gives a detailed account of the biofuel production from algae, bioproducts extraction, environmental applications of microalgae, and cyanobacteria for bioremediation.

Energy balance, GHG emission and economy for cultivation of high biomass verities of bamboo, sorghum and pearl millet as energy crops at marginal ecologies of Gujarat state in India

This study was carried out to explore biomass variety of sorghum, pearl millet and bamboo for second generation biofuel feedstock production at salinity and drought prone marginal land at three districts of Gujarat state, India. The biomass feedstock under study were compared with the native crop varieties for its economic sensitivity as well as native varieties of the same crops for energy and carbon dioxide equivalent (CO2eq) greenhouse gas (GHG) emission. Net income per matric tone of harvested biomass sorghum, pearl millet and bamboo were 52.02 USD, 20.37 USD and 124.66 USD respectively which is economically profitable as compared to native sorghum and pearl millet varieties. Bamboo showed highest net income of 8 USD/day based on the annual land occupancy which is double than biomass sorghum. Positive net energy balance of 454.29 GJ/Ha/crop cycle, 278.20 GJ/Ha/crop cycle and 602.49 GJ/Ha/Year were found for biomass sorghum, pearl millet and bamboo respectively. GHG emission was positive and lowest for bamboo 42.55 KgCO2eq/MT as compared to biomass sorghum 48.97 KgCO2eq/MT and pearl millet 74.53 CO2eq/MT. Cost benefit analysis revealed that bamboo has highest net income, lowest GHG emission, highest net energy balance and highest biomass production per USD spent among the other biomass crops.

Effects of fertilization, plant species, and intra-specific diversity on soil carbon and nitrogen in biofuel cropping systems after five growing seasons

Land-use change for bioenergy production can release greenhouse gases (GHG) through disturbance of soil carbon (C) pools, but use of native species with extensive root systems as bioenergy crops may help mitigate GHG emissions by enhancing soil C sequestration. Here, we investigated how (1) fertilization, (2) plant species and cultivars, and (3) inter- and intra-specific diversity affect soil C and N accumulation five growing seasons after conversion of an old-field dominated by C3 grasses to a grassland dominated by C4 perennial grasses managed for biofuel production. We manipulated diversity at both the species- and cultivar level, and applied nitrogen (N) at two levels (0 and 67 kg ha−1). Establishment of C4 grass treatments on soils that supported C3 pasture grasses for 36 years enabled us to use the natural abundance C isotope ratio technique to estimate the contribution of new C4 plant-derived C to soil organic matter pools. Our study yielded three main results: 1) annual fertilization did not significantly affect soil C and N concentrations after five growing seasons; 2) increasing inter- and intra-specific diversity did not significantly increase soil C and N concentrations; 3) cultivar- and species identity influenced C4-derived C and total soil C concentrations: big bluestem dominated stands exhibited greater soil C accrual relative to stands dominated by switchgrass and mixed-species treatments. Future research is needed to further assess how big bluestem can aid in the sustainable provisioning of second generation biofuel feedstocks.

Comprehensive feasibility assessment of a poly-generation process integrating fast pyrolysis of S. japonica and the Rankine cycle

Marine macroalgae or seaweeds are increasingly becoming strong candidates for sustainable biofuel feedstocks of the future. This study features a large-scale process design and comprehensive analysis of an industrial-scale (400,000 tons dry feedstock per year) poly-generation pyrolysis process that utilizes 3rd generation biofuel feedstock, Saccharina japonica brown seaweed, and produces diesel-range hydrocarbon fuel, heat, and power. Process design relied predominately on published experimental data regarding fast pyrolysis of S. japonica in a fixed-bed reactor system, followed by dewatering and catalytic upgrading of the produced biocrude. The design featured acid wash pretreatment for the reduction of mineral content, and subsequently a Rankine power cycle utilizing biochar. The design also considered two distinct cases of on-site hydrogen production and hydrogen purchase. Based on the experimental data, a rigorous steady-state flowsheet model was constructed using Aspen Plus for each design case. The results of comprehensive techno-economic assessment, sensitivity, and Monte Carlo analyses provided insight into capital cost for the process, minimum product selling price, and selling price ranges. Finally, the process is compared with traditional crude oil extraction and processing in terms of significant reductions in CO2 emissions, hence providing strong evidence of its environmental sustainability.

Biofuels for Defence Use: Past, Present And Future

Defence sector desires to attain energy self-sufficiency and security. In recent years, emergence of biofuel as an alternative source has raised the hopes of Defence. Ethanol and bio-diesel are currently being used as blends in different parts of the world. While, bio-diesel is mostly being blended in 2-20% in different parts of the world, ethanol blending has reached upto 85%. Owing to the sustainability reasons, the choice of feedstock for ethanol production is gradually changing from corn to lignocelluloses biomass. Jatropha curcas, is still the choice feedstockfor bio-diesel in most third world countries. This institute has put in rigrous efforts to identify high yielding varieties of Jatropha, improving its yield, standardizing trans-esterification to obtain high quality bio-diesel and its trials and testing in various vehicles and equipment. Second generation biofuels using biomass such as farm and forest wastes as feedstocks are promising in terms of their overall sustainability and volume produced. They can be used as drop in fuels. However, time is required to utilize their potential fully. Algae, the third generation biofuel feedstock still needs extensive R&D to make it economically sustainable. Whatever, the technology used, defence forces will accept any biofuel, which should be available constantly and priced below the existing petroleum fuels. The scope of producing by-products and finding a lucarative market for these products can ensure that prices ofbiofuels remain lower than the petroleum fuels

Utilization of algae for biofuel, bio-products and bio-remediation

Abstract Algae are considered as a promising source for biofuel and bio-products. Algae contain carbohydrates, lipids, proteins and their photosynthetic and lipid accumulating potential makes them a suitable candidate for bioenergy. Algal biomass is used in the production of biofuels like biodiesel, bioethanol, biobutanol, and biohydrogen etc. Therefore, this review provides an overview on the usage of algal biomass in multiple applications like fuel, food and environment. Initially, evolution of first and second generation biofuel feedstocks and their limitations have been described. Later, advantages of third generation biofuel feedstock i.e., algae over first and second generation feedstock were discussed comprehensively. Apart from bioenergy production from algae, industrially important co-products or value added products extracted from microalgae were addressed. Various microalgae utilized for the extraction of omega-3 fatty acids were listed. Eventually, environmental application of microalgae namely wastewater treatment and CO2 sequestration were presented.

Economic analysis of sorghum plant cultivation as biomass source for 2nd generation biofuel feedstock

Sorghum plant (Sorghum bicolor L.) is a potential cereal plant to be cultivated and utilized. Currently, sorghum cultivation is not well developed and sorghum production is still very low, despite the fact that sorghum biomass including its roots, stems, and leaves is very potential to be utilized as 2nd generation biofuel feedstock. The utilization of sorghum for 2nd generation biofuel has several advantages, such as not competing with food, recent developing technology reduces the conversion cost of production process, and it is environmentally friendly. Therefore, the aim of this research was to calculate the economic feasibility of sorghum cultivation in order to fulfill the requirement of biomass feedstock for bio-oil industry, with calculation performed for capacity of 100, 200 and 2,000 tons/day. The feasibility calculation results of the sorghum cultivation business showed that the sorghum cultivation for biomass requirements of the bio-oil plant is feasible for all capacities. For all capacities, the business is still feasible when there is a 50% increase in seed prices, and it becomes unfeasible when the selling price of sorghum seeds decreases starting from 5%.

Differential expression of hormone related genes between extreme segregants of a Saccharum interspecific F2 population

Sugarcane is a highly productive, first generation biofuel feedstock, known for its remarkable efficiency in accumulating biomass. Hormones are important regulators for many biological processes in plants, especially in plant development and plant growth, which are crucial for plant biomass traits. To understand how hormones regulatory mechanisms contribute to sugarcane lignocellulose yield, we studied the transgressive segregation on biomass yield in the F2 population derived from a cross between Saccharum officinarum ‘LA Purple’ and Saccharum robustum ‘MOL5829’. Gene expression profiling was used to detect genes involved in three important hormone-related pathways, auxin, ethylene and gibberellin, to find out how they are differently regulated between the extreme segregants of high and low biomass yield groups. We identified seventeen differentially expressed genes in auxin, one in ethylene and one in gibberellin related signaling and biosynthesis pathways, which could potentially regulate biomass yield. Differentially expressed genes, PIF3 and EIL5, involved in gibberellin and ethylene pathway could play an important role in biomass accumulation. These plant hormone-related genes could serve as candidate genes in genetic modification and breeding programs to develop high yielding energy cane.

An Extended Approach to Quantify Triacylglycerol in Microalgae by Characteristic Fatty Acids.

Microalgae represent a third generation biofuel feedstock due to their high triacylglycerol (TAG) content under adverse environmental conditions. Microalgal TAG resides in a single cell and serves as a lipid class mixed with complicated compositions. We previously showed that TAG possessed characteristic fatty acids (CFAs) for quantification and was linearly correlated with the relative abundance of CFA within certain limits in microalgae. Here, we defined the application range of the linear correlation between TAG and CFA in the oleaginous microalgae Chlamydomonas reinhardtii and Phaeodactylum tricornutum. In addition, TAG quantification was further expanded to a wide range of levels and the absolute amounts of saturated or monounsaturated CFAs, 16:0 and 18:1n9 of C. reinhardtii and 16:0 and 16:1n7 of P. tricornutum, instead of polyunsaturated CFAs, were verified to be linearly correlated to TAG levels throughout the entire period of nitrogen stress. This approach utilizes a single fatty acid to quantify TAG mixtures, and is rapid, simple and precise, which provides a useful tool for monitoring TAG accumulation of distinct microalgal species and facilitating high-throughput mutant screening for microalgae.

Comparative Farm-Gate Life Cycle Assessment of Oilseed Feedstocks in the Northern Great Plains

Second generation biofuel feedstocks such as carinata (Brassica carinata L. Braun) and camelina (Camelina sativa L. Crantz) offer unique advantages over traditional bioenergy alternatives, such as canola (Brassica napus L.) or soybean (Glycine max L. Merr). As the global demand for food and livestock feed continues grow, the utility of canola and soybeans as a bioenergy resource is uncertain. This work focused on two oilseed alternatives for use as biofuel feedstocks across the semi-arid region of the Northern Great Plains. This analysis compared the geographic distribution of current yields, assessed the environmental impacts, and evaluated the energetic benefit of oilseed production at aggregated crop management zone levels through a life cycle assessment (LCA) methodology. The average regional LCA results for environmental and energetic impacts for carinata and camelina compared favorably to canola and soybeans and were found to represent sustainable biofuel feedstock alternatives for the study region. The estimated climate change impact of carinata and camelina offered a substantial benefit over that of canola and soybeans. The regional results for freshwater and marine eutrophication potential and the net energy results of carinata and camelina also compared favorably to canola and soybeans. The most environmentally and energetically beneficial feedstock varied based on geographic location within the region. Soybeans tended to perform well in southeastern South Dakota, canola performed well in northeastern North Dakota, and camelina and carinata remained strong alternatives comparatively across the region.

Hydrologic cost-effectiveness ratio favors switchgrass production on marginal croplands over existing grasslands.

Switchgrass (Panicum virgatum L.) has attracted attention as a promising second generation biofuel feedstock. Both existing grasslands and marginal croplands have been suggested as targets for conversion to switchgrass, but the resulting production potentials and hydrologic impacts are not clear. The objectives of this study were to model switchgrass production on existing grasslands (scenario-I) and on marginal croplands that have severe to very severe limitations for crop production (scenario-II) and to evaluate the effects on evapotranspiration (ET) and streamflow. The Soil and Water Assessment Tool (SWAT) was applied to the 1063 km2 Skeleton Creek watershed in north-central Oklahoma, a watershed dominated by grasslands (35%) and winter wheat cropland (47%). The simulated average annual yield (2002–2011) for rainfed Alamo switchgrass for both scenarios was 12 Mg ha-1. Yield varied spatially under scenario-I from 6.1 to 15.3 Mg ha-1, while under scenario-II the range was from 8.2 to 13.8 Mg ha-1. Comparison of average annual ET and streamflow between the baseline simulation (existing land use) and scenario-I showed that scenario-I had 5.6% (37 mm) higher average annual ET and 27.7% lower streamflow, representing a 40.7 million m3 yr-1 streamflow reduction. Compared to the baseline, scenario-II had only 0.5% higher ET and 3.2% lower streamflow, but some monthly impacts were larger. In this watershed, the water yield reduction per ton of biomass production (i.e. hydrologic cost-effectiveness ratio) was more than 5X greater under scenario-I than under scenario-II. These results suggest that, from a hydrologic perspective, it may be preferable to convert marginal cropland to switchgrass production rather than converting existing grasslands.

Potential Losses of Soil Nutrients and Energy Content on the Complete Removal of Sugarcane Leaf Material as a Biomass Feedstock

Green cane (unburnt) harvesting of sugarcane (Saccharum sp.) deposits between 6 and 24 Mg/ha of extraneous leaf material (residue) on the surface of soil. The removed leafy material has value as biomass for use as a potential second generation biofuel or bioproduct feedstock. Negative aspects of crop residue removal, however, are well documented and include reduced subsequent crop ratoon yields, reduced soil quality, increased soil erosion, and loss of soil fertility. The objective of the study was to determine the yield and nutrient content of sugarcane leaf material harvested from three Louisiana, USA, commercial sugarcane varieties HoCP 96-540, L 99-233, and L 99-226. Leafy material was harvested five times across two growing seasons: 2009 and 2010. Data varied by year due to weather conditions, but overall HoCP 96-540, L 99-226, and L 99-233 leaf yields were 11.5, 12.4, and 8.36 Mg/ha, respectively. Energy yields for HoCP 96-540, L 99-233, and L 99-226 were 190, 134, and 205 GJ/ha, based on bomb calorimeter measurements of leaf material valued at 16.5 MJ/kg. Average nitrogen, phosphorus, and potassium leaf nutrient yields that would not be returned to the soil were 74.0, 8.6, and 83.0 kg/ha/yr, respectively. Replacing these nutrients with chemical fertilizers would increase yearly fertilizer costs significantly. Overall, yields, and nutrient and energy contents of the sugarcane leaf material were similar to other potential second generation cellulosic feedstocks for biofuels, and bioproducts. Since only the leaf material would be used as a biofeedstock, sugarcane harvest for sugar would not be affected. Thus, multiple land use criteria could be achieved.

Resolving the policy paradox: the case of biofuel production in Ireland

Purpose The purpose of this paper is to determine the status of policy design and policy implementation in the biofuel sector in Ireland. The focus of the work addresses the overarching operational context of the biofuel sector in Ireland and the role of different actors in shaping and resolving inconsistencies in policy outlook and practice. Design/methodology/approach This study used a qualitative research approach involving a series of semi-structured interviews with members of the relevant sub-groups concerned. This study sought to address two questions – whether current or proposed policy is likely to affect consumption of indigenous biofuel feedstocks in the biofuel sector and what are the controlling factors in the demand for indigenous feedstocks for biofuel. Findings Outcomes suggest that while Irish government policy recognises the need to support the development of renewable energy, it also operates under a number of parallel and potentially inconsistent paradigms in relation to biofuels as a renewable energy commodity. It is contended that the outcome of this position is a lack of coherent and coordinated policy in the area of biofuel production, including second generation biofuel using indigenous feedstocks. Originality/value This paper provides a new cross sectoral perspective on the status of biofuel policy in Ireland with particular reference to second generation biofuel feedstocks. It focuses analysis on the nature of policy-operational inconsistencies and the need for a deeper ecological perspective in governance.

Dedicated Energy Crops and Crop Residues for Bioenergy Feedstocks in the Central and Eastern USA

AbstractDedicated energy crops and crop residues will meet herbaceous feedstock demands for the new bioeconomy in the Central and Eastern USA. Perennial warm-season grasses and corn stover are well-suited to the eastern half of the USA and provide opportunities for expanding agricultural operations in the region. A suite of warm-season grasses and associated management practices have been developed by researchers from the Agricultural Research Service of the US Department of Agriculture (USDA) and collaborators associated with USDA Regional Biomass Research Centers. Second generation biofuel feedstocks provide an opportunity to increase the production of transportation fuels from recently fixed plant carbon rather than from fossil fuels. Although there is no “one-size-fits-all” bioenergy feedstock, crop residues like corn (Zea maysL.) stover are the most readily available bioenergy feedstocks. However, on marginally productive cropland, perennial grasses provide a feedstock supply while enhancing ecosystem services. Twenty-five years of research has demonstrated that perennial grasses like switchgrass (Panicum virgatumL.) are profitable and environmentally sustainable on marginally productive cropland in the western Corn Belt and Southeastern USA.

Application of stochastic analytic hierarchy process for evaluating algal cultivation systems for sustainable biofuel production

Algal biomass is considered as a promising source of alternative fuel energy given its high yield per land area and other potential benefits. Categorized as an advanced generation biofuel feedstock, microalgae are grown in non-conventional ways through different cultivation systems. A preference of a cultivation system may vary depending on a given scenario and its inherent configuration (strength and weakness). Hence, the usage of a specific cultivation system to sustainably produce algal biofuels depends on various factors. Thus, a multi-criteria approach based on analytic hierarchy process (AHP) is proposed for evaluating alternative cultivation systems for sustainable production of algal biofuels. The main criteria considered to evaluate the alternatives based on consultation with a panel of expert and from literature are environmental impact, energy consumption, economic viability, social acceptability, and system robustness. Sub-criteria were identified under each main criterion to further qualify the analysis into relevant sub-factors in the sustainable production of algal biofuels. Three cultivations systems were used as an example to demonstrate the developed decision model using qualitative data and quantitative data. Probabilistic scenarios were analyzed using stochastic approach via Monte Carlo simulation. The results of the stochastic-based AHP showed which cultivation system is preferred for conservative (risk-averse) and optimistic (risk-inclined) scenarios.

Cultivation Of Microalgae (Chlorella vulgaris) For Biodiesel Production

Abstract Production of biofuel from renewable sources is considered to be one of the most sustainable alternatives to petroleum sourced fuels. Biofuels are also viable means of environmental and economic sustainability. Biofuels are divided into four generations, depending on the type of biomass used for biofuels production. At present, microalgae are presented as an ideal third generation biofuel feedstock because of their rapid growth rate. They also do not compete with food or feed crops, and can be produced on non-arable land. Cultivation conditions (temperature, pH, light, nutrient quantity and quality, salinity, aerating) are the major factors that influence photosynthesis activity and behaviour of the microalgae growth rate. In this paper, we present an overview about the effect of cultivation conditions on microalgae growth.

Life cycle analysis and soil organic carbon balance as methods for assessing the ecological sustainability of 2nd generation biofuel feedstock

The Life Cycle Assessment (LCA) method is the instrument of choice for quantifying environmental impacts; in particular, it is useful for estimating greenhouse gas (GHG) emissions associated with bioethanol production from agricultural residues such as straw. The LCA methodology considers process steps across bioethanol production from the crude feedstock to the standardized product bioethanol. However, agro-ecological constraints concerning raw material availability, such as the long-term conservation of soil fertility through the incorporation of straw on the field, are not taken into account within current LCA methodologies. Therefore, in this study, a method for soil organic carbon balancing was applied to ensure the sustainable supply of biomass. In addition to the GHG balance of bioethanol production from straw, the potential availability of straw for energy conversion was estimated on the regional level for Germany and its Federal States. The results of the GHG balance were heavily dependent on the chosen allocation method between grain and straw, and the amount of straw available for potential use as an energy source was largely determined by the structure of existing agricultural production. Potential regions for a 2nd generation bioethanol plant based on the available quantity of feedstock straw are shown in a case study for the German provinces.