Search

Copyright of Mexican Journal of Economics & Finance / Revista Mexicana de Economia y Finanzas is the property of Instituto Mexicano de Ejecutivos de Finanzas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Many tropical islands, including Aruba, Seychelles, Mauritius, and Pacific Island countries, are entirely dependent on importing fossil fuels to meet their energy demands. Due to global warming, improving energy use efficiency and developing regionally available renewable energy resources are necessary to reduce carbon emissions. This review analyzed and identified biomass feedstocks to produce liquid biofuels targeting tropical islands, particularly focusing on Hawaii as a case study. Transportation and energy generation sectors consume 25.5% and 11.6%, respectively, of Hawaii's imported fossil fuels. Various nonedible feedstocks with information on their availability, production, and average yields of oils, fiber, sugars, and lipid content for liquid biofuels production are identified to add value to the total energy mix. The available biomass conversion technologies and production costs are summarized. In addition, a section on potentially using sewage sludge to produce biodiesel is also included. Based on a comparative analysis of kamani, croton, pongamia, jatropha, energycane, Leucaena hybrid, gliricidia, and eucalyptus feedstock resources, this study proposes that Hawaii and other similar tropical regions can potentially benefit from growing and producing economical liquid biofuels locally, especially for the transportation and electricity generation sectors. [ABSTRACT FROM AUTHOR]

A biorefinery purchasing feedstock (perennial grass) must offer contracts that provide the same opportunity to earn a profit for a feedstock contractor located 50 or 5 km from the biorefinery. The business plan presented here specifies that the biomass is purchased in satellite storage locations (SSLs), and the load-out and hauling costs are paid by the biorefinery. Contracts can be offered for harvest in September, October, and November, a three-month harvest window, or the harvest window can be extended to December, January, and February, a six-month harvest window. Required total storage capacity is 75% of annual consumption for the three-month window and 50% for the six-month window, a significant difference in total storage capacity (cost). The storage cost difference paid by the biorefinery is 5.27 and 3.52 USD/Mg for the three-month and six-month, respectively. Several issues must be addressed in the feedstock contracts: (1) earlier harvest, before plant senescence, means less nutrients are translocated back into the soil and more are removed at harvest; (2) harvest losses are higher for all harvests after the September harvest; and (3) storage losses increase with storage time in the SSL. Time of removal from the SSL is dictated by the biorefinery; thus, the feedstock contractor must be compensated. The contracts paid by the biorefinery, averaged across the entire annual consumption, were about the same for the three-month window, and six-month window. This result was obtained because fertilizer cost decreases and harvest losses increase as the harvest date increases; thus, the two factors tend to offset. Using a 77 USD/Mg base cost, representative feedstock payment at the SSL (no storage losses included) for contractors with various month contracts are September (84.30), October (85.54), November (86.72), December 88.63), January (89.98), and February (90.58). Subsequent compensation for storage losses depends on the amount of time the particular unit of biomass is in storage before shipment. [ABSTRACT FROM AUTHOR]

This article is a review of the scientific literature published in 2019 on topics relating to bioenergy from biofuel residues and waste. This literature review is divided into the following sections: Feedstocks, Biodiesel, Bioethanol, Hydrogen, Biohydrogen, Biofuel Residues, Microalgae, and Lignocelluloses. [ABSTRACT FROM AUTHOR]

Worldwide, there are various feedstocks such as straws, corn stover, sugarcane bagasse, sweet sorghum bagasse (SSB), grasses, leaves, whey permeate, household organic waste, and food waste (FW) that can be converted to valuable biofuels such as butanol. For the present studies, an economic analysis was performed to compare butanol production from three feedstocks (SSB; FW; and yellow top presscake, YTP or YT) using a standard process and an advanced integrated process design. The total plant capacity was set at 170,000–171,000 metric tons of total acetone butanol ethanol (ABE) per year (99,300 tons of just butanol per year). Butanol production from SSB typically requires pretreatment, separate hydrolysis, fermentation, and product recovery (SHFR). An advanced process was developed in which the last three steps were combined into a single unit operation for simultaneous saccharification, fermentation, and recovery (SSFR). For the SHFR and SSFR plants, the total capital investments were estimated as $213.72 × 106 and $198.16 × 106, respectively. It was further estimated that the minimum butanol selling price (using SSB as a feedstock) for the two processes were $1.14/kg and $1.05/kg. Therefore, SSFR lowered the production cost markedly compared to that of the base case. Butanol made using FW had an estimated minimum selling price of only $0.42/kg. This low selling price is because the FW to butanol process does not require pretreatment, hydrolysis, and cellulolytic enzymes. For this plant, the total capital investment was projected to be $107.26 × 106 . The butanol selling price using YTP as a feedstock was at $0.73/kg and $0.79/kg with total capital investments for SSFR and SHFR of $122.58 × 106 and $132.21 × 106, respectively. In the Results and Discussion section, the availability of different feedstocks in various countries such as Brazil, the European Union, New Zealand, Denmark, and the United States are discussed. Additionally, the use of various microbial strains and product recovery technologies are also discussed. [ABSTRACT FROM AUTHOR]

This section presents a review of the scientific literature published in 2018 on topics relating to sustainable bioenergy from biofuel residues and waste. This review is divided into the following sections: Feedstocks, Bioethanol, Biodiesel, Biohydrogen, Hydrogen, Biofuel Residues, Microalgae, and Lignocelluloses. [ABSTRACT FROM AUTHOR]

Genetic improvement through breeding is one of the key approaches to increasing biomass supply. This paper documents the breeding progress to date for four perennial biomass crops (PBCs) that have high output–input energy ratios: namely Panicum virgatum (switchgrass), species of the genera Miscanthus (miscanthus), Salix (willow) and Populus (poplar). For each crop, we report on the size of germplasm collections, the efforts to date to phenotype and genotype, the diversity available for breeding and on the scale of breeding work as indicated by number of attempted crosses. We also report on the development of faster and more precise breeding using molecular breeding techniques. Poplar is the model tree for genetic studies and is furthest ahead in terms of biological knowledge and genetic resources. Linkage maps, transgenesis and genome editing methods are now being used in commercially focused poplar breeding. These are in development in switchgrass, miscanthus and willow generating large genetic and phenotypic data sets requiring concomitant efforts in informatics to create summaries that can be accessed and used by practical breeders. Cultivars of switchgrass and miscanthus can be seed‐based synthetic populations, semihybrids or clones. Willow and poplar cultivars are commercially deployed as clones. At local and regional level, the most advanced cultivars in each crop are at technology readiness levels which could be scaled to planting rates of thousands of hectares per year in about 5 years with existing commercial developers. Investment in further development of better cultivars is subject to current market failure and the long breeding cycles. We conclude that sustained public investment in breeding plays a key role in delivering future mass‐scale deployment of PBCs. Plant breeding links the research effort with commercial mass upscaling. The authors' assessment of development status of the four species is shown (poplar having two: one for short rotation coppice (SRC) poplar and one for the more traditional short rotation forestry (SRF)). Mass scale deployment needs developments outside the breeding arenas to drive breeding activities more rapidly and extensively. [ABSTRACT FROM AUTHOR]

This section presents a review of the scientific literature published in 2017 on topics relating to sustainable bioenergy from biofuel residues and waste. This review is divided into the following sections: Feedstocks, Bioethanol, Biodiesel, Biohydrogen, Hydrogen, Biofuel Residues, Microalgae, Lignocelluloses and other topics. [ABSTRACT FROM AUTHOR]

Abstract: Worldwide production capacities of carbon‐based chemicals and associated products are steadily increasing. At the same time the reduction of greenhouse gas emissions such as carbon dioxide is of paramount importance in order to mitigate the anthropogenic impact of climate change. In Carbon2Chem® a cross industrial network develops concepts towards the utilization of steel mill gases for the sustainable production of “green” base chemicals, including methanol. This Review describes the technological challenges emerging from the use of these alternative feedstocks, specifically in the context of methanol production processes. [ABSTRACT FROM AUTHOR]

This review includes works published in the general scientific literature during 2016 on the production of bioenergy and biofuel from waste residues generated during bioethanol and biodiesel production with a brief overview of current and emerging feedstocks. A section of this review summarizes literature on culturing algae for biofuels including bioreactors and open pond cultivation systems with the utilization of inorganic and organic sources of nutrients. New methods applicable to the mass culture of algae are highlighted. Algal cell harvesting and oil extraction techniques are discussed along with policies and economics. [ABSTRACT FROM AUTHOR]

Multiple factors including climate change, price uncertainties, and geopolitical instability have prompted many industries to investigate the feasibility of replacing traditional petroleum-based fuels with biofuel alternatives. However, to make this transition successful, these new biofuels must be environmentally sustainable and the necessary support infrastructure must be in place to make the production, distribution, and storage of these biofuels technologically feasible and cost effective. Developing a value chain, spanning from feedstock production to distribution to end users, requires garnering buy-in from multiple stakeholders by demonstrating environmental, economic, and social benefits and incentives. Two critical factors are the environmental benefits achieved from the use of the biofuel technology and the degree of resilience of the value chain to emergent conditions to ensure steady supply to consumers. Moreover, different biofuel pathways have different costs, benefits, and risks which must be compared. In this paper, we describe how environmental sustainability can be modeled using life cycle assessment (LCA) and how the resilience of value chain initiatives can be modeled using a scenario-based decision model. We then describe how sustainability and resilience assessments can be integrated in an iterative, anticipatory LCA framework. These assessments can be used as the basis for a business case for various investments, as well as a means for promoting responsible innovations, with the aviation industry used as a case study. [ABSTRACT FROM AUTHOR]

This review includes works published in the general scientific literature during 2015 on the production of bioenergy and biofuel from waste residues generated during bioethanol and biodiesel production with a brief overview of current and emerging feedstocks. A section of this review summarizes literature on culturing algae for biofuels including bioreactors and open pond cultivation systems with the utilization of inorganic and organic sources of nutrients. New methods applicable to the mass culture of algae are highlighted. Algal cell harvesting and oil extraction techniques tested and developed for algae discussed alongwith policies and economics are also provided. [ABSTRACT FROM AUTHOR]

This review includes works published in the general scientific literature during 2014 on the production of bioenergy and biofuel from waste residues generated during bioethanol and biodiesel production with a brief overview of current and emerging feedstocks. Another section of this review summarizes literature on culturing algae for biofuels including bioreactors and open pond cultivation systems with the utilization of inorganic and organic sources of nutrients. New methods applicable to the mass culture of algae are highlighted. Algal cell harvesting and oil extraction techniques tested and developed for algae are also discussed. [ABSTRACT FROM AUTHOR]

Short rotation woody bioenergy crops (SRWC) could contribute a substantial portion of the biomass required to meet federal mandates and offset carbon emissions. One SRWC with strong bioenergy potential is black locust ( Robinia pseudoacacia L.), planted extensively for wood and energy applications globally, but under-studied in its native US. This member of the Fabaceae family can fix nitrogen, tolerate stress, and sequester carbon while generating biomass yields up to 14 Mg ha yr. This article offers a comprehensive state-of-the-art review of production practices, biomass and energy yield estimates, environmental risks and benefits, and economic considerations for this promising feedstock. [ABSTRACT FROM AUTHOR]

Given the mandated increases in fuel production from alternative sources, limited high-quality production land, and predicted climate changes, identification of stress-tolerant biomass crops will be increasingly important. However, existing literature largely focuses on the responses of a small number of crops to a single source of abiotic stress. Here, we provide a much-needed review of several types of stress likely to be encountered by biomass crops on marginal lands and under future climate scenarios: drought, flooding, salinity, cold, and heat. The stress responses of 17 leading biomass crops of all growth habits (e.g., perennial grasses, short-rotation woody crops, and large trees) are summarized, and we identify several that could be considered 'all purpose' for multiple stress types. Importantly, we note that some of these crops are or could become invasive in some landscapes. Therefore, growers must take care to avoid dissemination of plants or propagules outside of cultivation. [ABSTRACT FROM AUTHOR]

This review includes works published in the general scientific literature during 2013 on the production of bioenergy and biofuel from waste residues generated from bioethanol and biodiesel production with a brief overview of current and emerging feedstocks. A later section of this review summarizes literature on culturing algae for biofuels including bioreactors and open pond cultivation systems with the utilization of inorganic and organic sources of nutrients. New methods applicable to the mass culture of algae are highlighted. Algal cell harvesting and oil extraction techniques tested and developed for algae are also discussed. [ABSTRACT FROM AUTHOR]

Whole trees from energy thinnings constitute one of many forest fuel sources, yet ten widely applied supply chains could be defined for this feedstock alone. These ten represent only a subset of the real possibilities, as felling method was held constant and only a single market (combustion of whole tree chips) was considered. Stages included in-field, roadside landing, terminal, and conversion plant, and biomass states at each of these included loose whole trees, bundled whole trees or chipped material. Assumptions on prices, performances, and conversion rates were based on field trials and published literature in similar boreal forest conditions. The economic outcome was calculated on the basis of production, handling, treatment and storage costs and losses. Outcomes were tested for robustness on a range of object volumes (50–350 m3solid), extraction distances (50–550 m) and transport distances (10–70 km) using simulation across a set of discrete values. Transport was calculated for both a standard 19.5 m and an extended 24 m timber truck. Results showed that the most expensive chain (roadside bundling, roadside storage, terminal storage and delivery using a 19.5 m timber truck) at 158 € td -1 was 23% more costly than the cheapest chain (roadside chipping and direct transport to conversion plant with container truck), at 128 € td -1. Outcomes vary at specific object volumes and transport distances, highlighting the need to verify assumptions, although standard deviations around mean supply costs for each chain were small (6%-9%). Losses at all stages were modelled, with the largest losses (23 € td -1) occurring in the chains including bundles. The study makes all methods and assumptions explicit and can assist the procurement manager in understanding the mechanisms at work. [ABSTRACT FROM AUTHOR]

Abstract: Energy conservation has emerged as one of the biggest challenges of the world in the XXI century, and not different from many countries, the US has created plans and policies to stimulate renewable energy alternative. Among the important alternatives for energy conservation is the use of biomass energy. Despite these stimuli production predictions are not confident that production would achieve the planned target for the U.S. Consequently, the predictions raise questions about farmer's willingness to grow bioenergy crops or produce alternative cellulosic feedstocks. In other words, farmers and landholders may not be willing to grow bioenergy crops. With this concerns in mind, the study advances previous research about bioenergy production by evaluating farmer's and landholder's willingness to produce different varieties of biofuel feedstocks. To achieve our goals, we used a mail survey of Kansas farmers conducted from January to April of 2011. The survey contained questions related to how farmers make their land-use decisions covering a wide array of topics. Through this survey, we evaluate the effect of farm characteristics, farm management practices, farmer perceptions (such as risk aversion), physical variables (such as soil, weather, and the availability of water for irrigation) on farmers' willingness to produce value-added feedstocks (e.g., corn stover), dedicated annual bioenergy crops (e.g., energy sorghum), and dedicated perennial bioenergy crops (e.g., switchgrass) for biofuel production in Kansas, though the use of logistic regressions and marginal effects. [Copyright &y& Elsevier]

In present work our objective was to find out the potential substrates for fermentative hydrogen production using microbial culture of Bacillus firmus NMBL-03 isolated from municipal sludge. A wide variety of substrates (glucose, xylose, arabinose, lactose, sucrose, and starch) and carbohydrate rich waste products (bagasse hydrolysate, molasses, potato peel and cyanobacterial mass) have been used for dark fermentative hydrogen production. All studies were done at optimized physico-chemical conditions. Among all substrates glucose, arabinose, lactose, starch, molasses and bagasse hydrolysate were found to be the favorable substrates for hydrogen production. The highest VHPR i.e. 177.5 ± 7.07 ml/L.h (7.95 ± 0.29 mmol H2/L.h) and maximum H2 production (22.58 ± 2.65 mmol H2/L) was achieved using starch as the substrate. The maximum yield 1.29 ± 0.11 mol H2/mol reducing sugar was obtained from bagasse hydrolysate as substrate. Butyrate and acetate were detected as the end product in all the cases while lactate was also detected from glucose and cyanobacterial hydrolysate. Since considerable amount of H2 also evolved when cyanobacterial mass was used, therefore this microbe can be exploited for hydrogen production through a three stage integrated system. Residual carbohydrate containing biomass left after cyanobacterial H2 production can be utilized in dark fermentative H2 production. Spent media obtained after dark fermentative H2 production contain considerable amount of volatile fatty acids that can be potential substrate for photo fermentative H2 production. [ABSTRACT FROM AUTHOR]

The Feedstock Readiness Level (FSRL) tool was developed by the US Department of Agriculture, US Federal Aviation Administration, and Research and Innovative Technology Administration to describe the steps involved in bringing plant-based feedstocks to market for aviation biofuels production. A candidate feedstock is assigned a FSRL level from 1 through 9, indicating an increasing level of maturity towards commercialization. The FSRL level also communicates the state of development of a feedstock concurrent with its readiness for use with a conversion process. There are four components to the FSRL (production, market, policy, and linkage to conversion process), each with one to four tollgate descriptions per readiness level. The FSRL tool was structured to complement the Fuel Readiness Level (FRL) tool in use by the aviation industry as an internationally recognized communication best practice. Similarly, the FSRL can be used to identify gaps in any feedstock supply chain designed for any biofuel or conversion process that provides a market for feedstocks. This integrated feedstock and conversion technology approach can facilitate a coordinated allocation of resources to effectively plan for and develop a viable aviation biofuels industry. [ABSTRACT FROM AUTHOR]

Abstract: As the world confronts a reported food shortage and rising fuel prices, scientists around the globe are scrambling to develop biofuel feedstocks that would not divert food crops to energy. It is apparent that the demand for biodiesel is expected to increase in near future and although many edible oils might be the cheapest feedstock for biofuel production. But it may not be sustainable source to meet this increasing demand. This justifies the need to use non-edible oil seeds that can be the reliable sustainable feedstock for biofuel production. Furthermore, most of the non-edible seeds bearing trees have the potentials of reclaiming wasteland and does not compete with food crop for limited growing regions. It thus becomes imperative to search for dedicated non-edible feedstocks and their suitability for biodiesel production. This paper attempts to make an assessment of current energy scenario, potential of non-edible oil over edible oils, selected non-edible oil seeds as biodiesel feedstocks, impact of biofuel on environment and future direction. Experimental analysis by different researchers on these non-edible oils showed their great potential as feedstocks for biodiesel production. This paper also reviews the biology, distribution and chemistry of selected non-edible oil seeds plants. [Copyright &y& Elsevier]

Abstract: In this article, we attempt to find the spatial relations between deforestation and biofuel production at global level by analyzing available global deforestation and biofuels data, and find that, for a variety of reasons relating to data availability and its characteristics, and the way biofuels are produced, this task is extremely difficult if not virtually impossible. Then we bring down the scale of the analysis to the case study level and provide a detailed methodology for analyzing the spatial relation between deforestation and biofuel development. We argue that this multi-scale approach, based on systematic sampling at the case study level would help to better understand the relation between biofuels and deforestation. Given the fact that biofuels are a highly contested approach to reduction of global carbon emissions, and that different lobbies in this debate are making claims that deforestation is, or is not, occurring as a result of the expansion of biofuel production, clarity on the methodological difficulties of making statements of this kind, at least in a global spatial analysis, may help avoid false conclusions being promulgated in the future. [Copyright &y& Elsevier]