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Abstract This study sought to quantify and characterize cassava waste as fuel. The wastes from three cultivars were collected to study and were divided into three distinct parts of the cassava plant: seed stem, thick stalks, and thin stalks. Physical and chemical analyzes were carried out to determine the elemental composition of the waste: volatile matter; fixed carbon; ash; moisture; lignin; cellulose; hemicellulose; ash composition and higher heating value were determined. We conducted a thermogravimetric analysis in oxidizing and inert atmospheres to study the behavior of the waste as fuel. The root productivity obtained ranged from 7.7 to 13.0 t ha−1 yr−1 on a dry basis (db), and the ratio between waste and roots varied from 0.36 to 0.91. The physical and chemical properties of cassava waste are analogous to those of woody biomass regarding the elemental composition, the higher heating value, and thermogravimetric analysis. Ash content varied from 2.5% to 3.5%, reaching around 6.0% in samples unwashed. Approximately 60% of the ashes are alkali oxides, especially P2O5, K2O, and CaO, which have low melting points. The alkali index calculated suggests that there is a strong tendency that the combustion process leads to ash fouling and the formation of ash deposits.

Abstract Bamboo has been considered a potential feedstock of energy for the future. It can be subjected to the pyrolysis for biofuels production. The thermogravimetric analysis (TGA) combined with differential thermogravimetric analysis (DTG) for bamboo was carried out prior to pyrolysis. The thermal degradation of bamboo was mainly between 230 and 420 °C. The conventional pyrolysis of bamboo was investigated in a bubbling fluidized-bed reactor using silica sand. The product distribution and composition of pyrolysis bio-oil were dependent on biomass component and operating conditions such as pyrolysis temperature, fluidization velocity, and particle size of biomass. The fractional catalytic pyrolysis of bamboo was also studied to upgrade the pyrolysis vapor, using HZSM-5 and red mud. The highest yield of bio-oil was 54.03 wt% compared to 49.14 wt% and 50.34 wt% of HZSM-5 and red mud catalyst, respectively. In the red mud catalytic pyrolysis, the oxygen content was rejected from pyrolysis vapor mostly via decarboxylation to produce more CO2 than CO; in contrast, for the HZSM-5 catalytic pyrolysis, the production of CO through decarbonylation was more favored than CO2. The main composition of catalytic pyrolysis bio-oil was 4-vinylphenol, which was employed as a raw material source to synthesize valuable material for energy storage.

Abstract To address the problem of fossil fuel usage at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and hydrogen use. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed Hydrogen production and End-Uses from CHHP system for the campus using local resources. Following the resource assessment study, the team selects FuelCell Energy DFC1500™ unit as a molten carbonate fuel cell to study of combined heat, hydrogen and power (CHHP) system based on a molten carbonate fuel cell fed by biogas produced by anaerobic digestion. The CHHP system provides approximately 650 kg/day. The total hydrogen usage 123 kg/day on the university campus including personal transportation applications, backup power applications, portable power applications, and other mobility applications are 56, 16, 29, 17, and 5 respectively. The excess hydrogen could be sold to a gas retailer. In conclusion, the CHHP system will be able to reduce fossil fuel usage, greenhouse gas emissions and hydrogen generated is used to power different applications on the university campus.

We tested this system with objectives to plan and apply this system in Japan, and examined its cooling effectiveness and ir flow generation

Abstract A huge inrush of PHEVs is envisioned in the future. There is a growing risk that, this proliferation in the number of PHEVs will trigger extreme surges in demand while charging them during rush hours. To mitigate this impact, a smart charging station is proposed in which the charging of the PHEVs is controlled in such a way that the impact of charging during peak load period is not felt on the grid. The power needed to charge the plug in hybrids comes from grid-connected photovoltaic generation or the utility or both. The three way interaction between the PV, PHEVs and the grid ensures optimal usage of available power, charging time and grid stability. The system designed to achieve the desired objective consists of a photovoltaic system, DC/DC boost converter, DC/AC bi-directional converter and DC/DC buck converter. The output of DC/DC boost converter and input of DC/AC bi-directional converter share a common DC link. A unique control strategy based on DC link voltage sensing is proposed for the above system for efficient transfer of energy.

Abstract Sweet sorghum, a C4 plant, is known to be a unique, versatile, and potential energy crop that can be separated into starchy grains, soluble sugar juice, and lignocellulosic biomass. The fermentable sugars in the juice (53–85% sucrose, 9–33% glucose, and 6–21% fructose) can be directly fermented into ethanol. The grain is primarily starch (62–75%), which can be hydrolyzed and fermented into ethanol. The bagasse, a fibrous lignocellulosic material, can be used to produce cellulosic ethanol, heat and/or power co-generation. In this review, the potential of sweet sorghum for bioenergy production (of various forms) using recently developed cultivars with improved agronomic performance was discussed. In addition, sweet sorghum was compared with other starch, sugar, and lignocellulosic feedstocks. Studies have been conducted on alternative pathways to convert whole sweet sorghum stalks and bagasse into bioenergy. However, very little review of the techno-economic analysis of bioenergy production and co-products from sweet sorghum has been published. The aim of this research was to review the current knowledge of agronomic requirement for cultivating sweet sorghum, the productivity of recently developed cultivars for bioenergy production, and pathways of converting sweet sorghum crop into bioenergy as well as the techno-economic feasibility of using sweet sorghum for bioenergy.

A full three-dimensional, non-isothermal computational fluid dynamics model of a tubular-shaped proton exchange membrane (PEM) fuel cell has been developed. This comprehensive model accounts for the major transport phenomena in a PEM fuel cell: convective and diffusive heat and mass transfer, electrode kinetics, and potential fields. In addition to the tubular-shaped geometry, the model feature an algorithm that allows for more realistic representation of the local activation overpotentials which leads to improved prediction of the local current density distribution. Three-dimensional results of the species profiles, temperature distribution, potential distribution, and local current density distribution are presented. The model is shown to be able to understand the many interacting, complex electrochemical, and transport phenomena that cannot be studied experimentally.

Abstract Performance of the ABE fermentation and integrated product recovery by cyclic vacuum was investigated in a 14-l bioreactor containing initial glucose concentration of 60 g l−1 at 35 °C. The cyclic operation consisted of 2 h-vacuum-cycles separated by 4 h-fermentation intervals at atmospheric pressure. Application of periodic vacuum sufficed to eliminate butanol inhibition of Clostridium beijerinckii 8052 culture, which tolerated alternate vacuum and atmospheric pressures. A 39% reduction in the energy requirement for acetone butanol ethanol (ABE) fermentation and in situ recovery by vacuum was achieved by changing the mode of vacuum operation from continuous (24 h vacuum time) to cyclic (12 h vacuum time). Analysis of the overall energy consumption for ABE fermentation and recovery (vacuum fermentation + distillation) demonstrated that cyclic vacuum ABE fermentation is more energy efficient than the conventional batch fermentation.

Abstract The primary objectives of this study are to evaluate the levelized cost of energy (LCOE) for different wave energy conversion strategies and to examine cost reduction pathways such that wave energy conversion projects are competitive, relative to alternative energy industries. The energy production of six different WEC devices was estimated for four sites along the U.S. Pacific coast. The LCOE of pilot-scale wave energy conversion projects was estimated to range between $0.07/kWh and $0.92/kWh higher than the target LCOE of those for early-market offshore wind energy projects. Device capacity factors were generally below the commonly assumed value of 30%. Methods of cost reduction to the target LCOE of $0.30/kWh were explored, including decreasing capital and operational expenditures (CAPEX and OPEX) and increasing annual energy production (AEP) through improvements in the wave energy resource and WEC and WEC array performance, and advanced controls. Results indicate that CAPEX and OPEX should be reduced by at least 45% and AEP should be increased by 200%. A reduction of CAPEX and OPEX by 75%, combined with array evaluation and control strategies capable of increasing AEP by 12%–55% could also result in LCOE for wave energy conversion projects of less than $0.30/kWh.