Biofuels Research Papers - Academia.edu (original) (raw)

Decarbonizing the transportation sector is critical to achieving global climate change mitigation. Although biofuels will play an important role in conventional gasoline and diesel applications, bioderived solutions are particularly... more

Decarbonizing the transportation sector is critical to achieving global climate change mitigation. Although biofuels will play an important role in conventional gasoline and diesel applications, bioderived solutions are particularly important in jet fuels and lubricants, for which no other viable renewable alternatives exist. Producing compounds for jet fuel and lubricant base oil applications often requires upgrading fermentation products, such as alcohols and ketones, to reach the appropriate molecular-weight range. Ketones possess both electrophilic and nucleophilic functionality, which allows them to be used as building blocks similar to alkenes and aromatics in a petroleum refining complex. Here, we develop a method for selectively upgrading biomass-derived alkyl methyl ketones with >95% yields into trimer condensates, which can then be hydrodeoxygenated in near-quantitative yields to give a new class of cycloalkane compounds. The basic chemistry developed here can be tailor...

Biomass is a potential energy resource that can be converted to hydrogen and is available from a wide range of sources. In this study, non-conventional biomass sources: soybean (Glycine max.), cassava (Manihot esculenta) and banana rachis... more

Biomass is a potential energy resource that can be converted to hydrogen and is available from a wide range of sources. In this study, non-conventional biomass sources: soybean (Glycine max.), cassava (Manihot esculenta) and banana rachis (Musa paradisiaca L.) had been tested for hydrogen production from biomass pyrolysis. The influence of biomass microstructure and reducing sugar content on the hydrogen production was studied through a high-energy ball-milling pre-process of the soybean source. The results

Production of biogas from different organic materials is a most interesting source of renewable energy. The biomethane potential (BMP) of these materials has to be determined to get insight in design parameters for anaerobic digesters.... more

Production of biogas from different organic materials is a most interesting source of renewable energy. The biomethane potential (BMP) of these materials has to be determined to get insight in design parameters for anaerobic digesters. Although several norms and guidelines for BMP tests exist, inter-laboratory tests regularly show high variability of BMPs for the same substrate. A workshop was held in June 2015, in Leysin, Switzerland, with over 40 attendees from 30 laboratories around the world, to agree on common solutions to the conundrum of inconsistent BMP test results. This paper presents the consensus of the intense roundtable discussions and cross-comparison of methodologies used in respective laboratories. Compulsory elements for the validation of BMP results were defined. They include the minimal number of replicates, the request to carry out blank and positive control assays, a criterion for the test duration, details on BMP calculation, and last but not least criteria fo...

En julio de 2014, el grupo de Trabajo Abierto de la Asamblea General de las Naciones Unidas propuso un documento con 17 objetivos para su aprobacion en septiembre de 2015. Este documento fijo las pautas para la promulgacion de los... more

En julio de 2014, el grupo de Trabajo Abierto de la Asamblea General de las Naciones Unidas propuso un documento con 17 objetivos para su aprobacion en septiembre de 2015. Este documento fijo las pautas para la promulgacion de los Objetivos de Desarrollo Sostenible y la agenda global de desarrollo en el periodo 2015 – 2030; esfuerzo que marca unas nuevas bases para los planes gubernamentales de crecimiento de las naciones. La propuesta de los Objetivos de Desarrollo Sostenible plantea unos retos para Colombia en diferentes sectores y una vision sistemica y no fraccionada del desarrollo para garantizar la sustentabilidad. En este documento se describen los incentivos fiscales en la produccion de biocombustible y se reflexiona en los dilemas que surgen a la luz de los Objetivos de Desarrollo Sostenible. Bajo este contexto surgen preguntas sobre los limites y alcances de los contadores publicos y su rol dentro del ejercicio profesional de la contabilidad ambiental.

Crop residues are common in rural Ghana due to the predominant role agriculture plays in livelihood activities in these communities. In this paper we investigate the prospects of exploiting agricultural crop residues for rural development... more

Crop residues are common in rural Ghana due to the predominant role agriculture plays in livelihood activities in these communities. In this paper we investigate the prospects of exploiting agricultural crop residues for rural development in Ghana through bioenergy schemes. A theoretical energy potential of 623.84 PJ per year, which is equivalent to 19,781 MW was estimated using crop production data from the Food and Agricultural Organization of the United Nations and residue-to-product ratios. Ghana has a total installed generation capacity of 4577 MW which is four times less the energy potential of crop residues in the country. Cocoa pod husks were identified as important biomass resources for energy generation as they are currently wasted. To further assess the energy potential of cocoa pod husks, different cocoa pod husks samples were collected across the six cocoa growing regions in Ghana and thermo-chemically characterised using proximate and ultimate analysis. The low levels of nitrogen and sulphur observed, together with the high heating value, suggest that cocoa pod husks and for that matter crop residues are eco-friendly feedstock that can be used to power rural communities in Ghana.

The present study deals with the biohydrogen production from starch-containing wastewater collected from the textile industry in Taiwan. The effects of inoculums collected from different sources (sewage sludge, soil and cow dung),... more

The present study deals with the biohydrogen production from starch-containing wastewater collected from the textile industry in Taiwan. The effects of inoculums collected from different sources (sewage sludge, soil and cow dung), substrate concentrations (5–25 g COD/L) and pH (4.0–8.0) on hydrogen production from wastewater were investigated.The cow dung seed had the highest hydrogen production of 101 mL with hydrogen content in biogas of 32.2%. It corresponds to a hydrogen yield (HY) of 1.56 mol H2/mol hexose and hydrogen production rate (HPR) of 0.93 L/L/d. Response surface methodology was used to evaluate the effects of initial cultivation pH (4.0–8.0) and substrate concentration (5–25 g COD/L) on the hydrogen production at 35 °C. At pH 7.0 with a wastewater concentration of 20 g COD/L, a maximum hydrogen production of 66 mL with 31.9% H2 and corresponding to an HY of 0.97 mol H2/mol hexose and an HPR of 1.14 L/L/d were obtained. According to the response surface analysis, the optimal conditions for high HPR were a wastewater concentration of 13 g COD/L at an initial cultivation pH of 7.0. The main soluble metabolic products were acetate and butyrate for hydrogen fermentation from textile wastewater.► The textile wastewater containing starch is a potential energy resource for anaerobic hydrogen fermentation. ► The optimum initial cultivation pH for H2production was 7.0. ► The optimum wastewater concentration for H2 production was 13 g COD/L. ► The main soluble metabolic products were acetate and butyrate.

Ideal bacterial support medium for fixed film denitrification processes/bioreactors must be inexpensive, durable and possess large surface area with sufficient porosity. The present study has been focussed on removing nitrate nitrogen at... more

Ideal bacterial support medium for fixed film denitrification processes/bioreactors must be inexpensive, durable and possess large surface area with sufficient porosity. The present study has been focussed on removing nitrate nitrogen at two different nitrate nitrogen loading rates (60 (NLR I) and 120 (NLR II) mg l-1) from simulated aquaculture wastewater. Coconut coir fibre and a commercially available synthetic reticulated plastic media (Fujino Spirals) were used as packing medium in two independent upflow anaerobic packed bed column reactors. Removal of nitrate nitrogen was studied in correlation with other nutrients (COD, TKN, dissolved orthophosphate). Maximum removal of 97% at NLR-I and 99% at NLR – II of nitrate nitrogen was observed in with either media. Greater consistency in the case of COD removal of upto 81% was observed at NLR II where coconut coir was used as support medium compared to 72% COD removal by Fujino Spirals. The results observed indicate that the organic support medium is just as efficient in nitrate nitrogen removal as conventionally used synthetic support medium. The study is important as it specifically focuses on denitrification of aquaculture wastewater using cheaper organic support medium in anoxic bioreactors for the removal of nitrate nitrogen; which is seldom addressed as a significant problem.

we are highlighting how the biofuel as an alternative fuel source, presents the advantages behind using such an energy source, challenges behind using it, and what is the expectation of this source on the future. We will go through Brazil... more

we are highlighting how the biofuel as an alternative fuel source, presents the advantages behind using such an energy source, challenges behind using it, and what is the expectation of this source on the future. We will go through Brazil as a country which is making benefits behind using this clean source; and the urges of its future on using this source.

This paper aims to provide a bibliometric analysis of publication trends on the themes of biomass and bioenergy worldwide. A wide range of studies have been performed in the field of the usage of biomass for energy production, in order to... more

This paper aims to provide a bibliometric analysis of publication trends on the themes of biomass and bioenergy worldwide. A wide range of studies have been performed in the field of the usage of biomass for energy production, in order to contribute to the green transition from fossil fuels to renewable energies. Over the past 20 years (from 2000 to 2019), approximately 10,000 articles have been published in the "Agricultural and Biological Sciences" field on this theme, covering all stages of production-from the harvesting of crops to the particular type of energy produced. Articles were obtained from the SCOPUS database and examined with a text mining tool in order to analyze publication trends over the last two decades. Publications per year in the bioenergy theme have grown from 91 in 2000 to 773 in 2019. In particular the analyses showed how environmental aspects have increased their importance (from 7.3% to 11.8%), along with studies related to crop conditions (from 10.4% to 18.6%). Regarding the use of energy produced, growing trends were recognized for the impact of biofuels (mentions moved from 0.14 times per article in 2000 to 0.38 in 2019) and biogases (from 0.14 to 0.42 mentions). Environmental objectives have guided the interest of researchers, encouraging studies on biomass sources and the optimal use of the energy produced. This analysis aims to describe the research evolution, providing an analysis that can be helpful to predict future scenarios and participation among stakeholders in the sector.

Economic analysis of an ARPA-e Electrofuels (http://arpa-e.energy.gov/?q=arpa-e-programs/electrofuels) process is presented, utilizing metabolically engineered Rhodobacter capsulatus or Ralstonia eutropha to produce the C30+ hydrocarbon... more

Economic analysis of an ARPA-e Electrofuels (http://arpa-e.energy.gov/?q=arpa-e-programs/electrofuels) process is presented, utilizing metabolically engineered Rhodobacter capsulatus or Ralstonia eutropha to produce the C30+ hydrocarbon fuel, botryococcene, from hydrogen, carbon dioxide, and oxygen. The analysis is based on an Aspen plus® bioreactor model taking into account experimentally determined Rba. capsulatus and Rls. eutropha growth and maintenance requirements, reactor residence time, correlations for gas-liquid mass-transfer coefficient, gas composition, and specific cellular fuel productivity. Based on reactor simulation results encompassing technically relevant parameter ranges, the capital and operating costs of the process were estimated for 5000 bbl-fuel/day plant and used to predict fuel cost. Under the assumptions used in this analysis and crude oil prices, the Levelized Cost of Electricity (LCOE) required for economic feasibility must be less than 2¢/kWh. While not...

The aim of this paper is to understand and to model the environmental performance of biodiesel produced by various Greek raw materials under current conditions. Three energy crops (rapeseed, sunflower and soybean) have been studied, with... more

The aim of this paper is to understand and to model the environmental performance of biodiesel
produced by various Greek raw materials under current conditions. Three energy crops (rapeseed,
sunflower and soybean) have been studied, with regard to their levels of biodiesel productivity.
Throughout the entire process, current Greek climatic conditions and cultivation parameters have been
taken into account. At the stage of assessment, we conclude that the environmental impacts per crop
area indicate that soybean has the lowest environmental impacts. However, by assessing the results per
quantity of produced biodiesel, the crop with the minimum environmental impacts is sunflower. This
paper shows that environmental benefits from biodiesel have better results, compared to conventional
diesel, thus leading to the conclusion that it is feasible to succeed improved environmental performance.

Background Pretreatment is a critical step in the conversion of lignocellulose to fermentable sugars. Although many pretreatment processes are currently under investigation, none of them are entirely satisfactory in regard to... more

Background Pretreatment is a critical step in the conversion of lignocellulose to fermentable sugars. Although many pretreatment processes are currently under investigation, none of them are entirely satisfactory in regard to effectiveness, cost, or environmental impact. The use of hydrogen peroxide at pH 11.5 (alkaline hydrogen peroxide (AHP)) was shown by Gould and coworkers to be an effective pretreatment of grass stovers and other plant materials in the context of animal nutrition and ethanol production. Our earlier experiments indicated that AHP performed well when compared against two other alkaline pretreatments. Here, we explored several key parameters to test the potential of AHP for further improvement relevant to lignocellulosic ethanol production. Results The effects of biomass loading, hydrogen peroxide loading, residence time, and pH control were tested in combination with subsequent digestion with a commercial enzyme preparation, optimized mixtures of four commercial ...

Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to... more

Algal biofuels and valuable co-products are being produced in both open and closed cultivation systems. Growing algae in open pond systems may be a more economical alternative, but this approach allows environmental microorganisms to colonize the pond and potentially infect or outcompete the algal “crop”. In this study, we monitored the microbial community of an outdoor, open raceway pond inoculated with a high lipid-producing alkaliphilic alga, Chlorella vulgaris BA050. The strain C. vulgaris BA050 was previously isolated from Soap Lake, Washington, a system characterized by a high pH (approximately 9.8). An outdoor raceway pond (200L) was inoculated with C. vulgaris and monitored for ten days and then the culture was transferred to a 2,000L raceway pond and cultivated for an additional six days. Community DNA samples were collected over the 16-day period in conjunction with water chemistry analyses and cell counts. Universal primers for the SSU rRNA gene sequences for Eukarya, Bacteria, and Archaea were used for barcoded pyrosequence determination. The environmental parameters that most closely correlated with C. vulgaris abundance were pH and phosphate. Community analyses indicated that the pond system remained dominated by the Chlorella population (93% of eukaryotic sequences), but was also colonized by other microorganisms. Bacterial sequence diversity increased over time while archaeal sequence diversity declined over the same time period. Using SparCC co-occurrence network analysis, a positive correlation was observed between C. vulgaris and Pseudomonas sp. throughout the experiment, which may suggest a symbiotic relationship between the two organisms. The putative relationship coupled with high pH may have contributed to the success of C. vulgaris. The characterization of the microbial community dynamics of an alkaliphilic open pond system provides significant insight into open pond systems that could be used to control photoautotrophic biomass productivity in an open, non-sterile environment.

Since the world faced the petroleum crisis in the 1970s and people started to realize the limitation of fossil energy resources coupled with concerns over the effects of increasing carbon dioxide in the atmosphere, major efforts were... more

Since the world faced the petroleum crisis in the 1970s and people started to realize the limitation of fossil energy resources coupled with concerns over the effects of increasing carbon dioxide in the atmosphere, major efforts were devoted to the search for alternative energy sources.

This article argues that, except in California, environmental justice considerations have not received sufficient attention in climate change policy debates. It explores the environmental justice implications of emerging domestic climate... more

This article argues that, except in California, environmental justice considerations have not received sufficient attention in climate change policy debates. It explores the environmental justice implications of emerging domestic climate change policies and provides policymakers with specific suggestions on how to integrate environmental justice concerns. The article begins by introducing the environmental justice movement and its central principles, and then