Umakanta Jena

Demineralization of Sargassum spp. Macroalgae Biomass: Selective Hydrothermal Liquefaction Process for Bio-Oil Production

Algae biomasses are considered a viable option for the production of biofuel because of their high yields of oil produced per dry weight. Brown macroalgae Sargassum spp. are one of the most abundant species of algae in the shores of Puerto Rico. Its availability in large quantity presents a great opportunity for use as a source of renewable energy. However, high ash content of macroalgae affects the conversion processes and the quality of resulting fuel products. This research studied the effect of different demineralization treatments of Sargassum spp. biomass, subsequent hydrothermal liquefaction (HTL) and bio-oil characterization. Demineralization constituted five different treatments: nanopure water, nitric acid, citric acid, sulfuric acid, and acetic acid. Performance of demineralization was evaluated by analyzing both demineralized biomass and HTL products by the following analyses: total carbohydrates, proteins, lipids, ash content, caloric content, metals analysis, Fourier Transform Infrared - Attenuated Total Reflectance (FTIR-ATR) Spectroscopy, Energy Dispersive Spectroscopy (EDS), Scanning Electron Microscopy (SEM), and GCMS analysis. HTL of Sargassum spp. before and after citric acid treatment, was performed in a 1.8 L batch reactor system at 350°C with a holding time of 60 min and high pressures (5-21 MPa). Demineralization treatment with nitric acid was found the most effective in reducing the ash content of the macroalgae biomass from 27.46% to 0.99% followed by citric acid treatment that could reduce the ash content to 7%. Citric acid did not show significant leaching of organic components such as carbohydrates and proteins, and represented a less toxic and hazardous option for demineralization. HTL of untreated and citric acid treated Sargassum spp. resulted in bio-oil yields of 18.4±0.1 % and 22.2±0.1 % (ash free dry basis), respectively.

Techno-economic feasibility and life cycle assessment of dairy effluent to renewable diesel via hydrothermal liquefaction.

The economic feasibility and environmental impact is investigated for the conversion of agricultural waste, delactosed whey permeate, through yeast fermentation to a renewable diesel via hydrothermal liquefaction. Process feasibility was demonstrated at laboratory-scale with data leveraged to validate systems models used to perform industrial-scale economic and environmental impact analyses. Results show a minimum fuel selling price of

Production of Biocrude Oil from Microalgae via Thermochemical Liquefaction Process

4.78 per gallon of renewable diesel, a net energy ratio of 0.81, and greenhouse gas emissions of 30.0g-CO2-eqMJ(-1). High production costs and greenhouse gas emissions can be attributed to operational temperatures and durations of both fermentation and hydrothermal liquefaction. However, high lipid yields of the yeast counter these operational demands, resulting in a favorable net energy ratio. Results are presented on the optimization of the process based on economy of scale and a sensitivity analysis highlights improvements in conversion efficiency, yeast biomass productivity and hydrotreating efficiency can dramatically improve commercial feasibility.

Evaluation of three cultivars of sweet sorghum as feedstocks for ethanol production in the Southeast United States

The current research is inline with enhancing the national energy security through production of biocrude oil from microalgae in an environmental friendly conversion process. Thermochemical liquefaction experiments have been conducted to study the feasibility of biocrude oil production from spirulina platensis, identify the optimum operating conditions, and investigate the possibility of production of other value added products. The independent parameters of the experiment were temperature, organic solid concentration, reaction time and catalytic conditions. Yield of bio-crude, product distribution and the conversion efficiency were monitored. Results have shown that about 30-48% of biocrude oil could be produced from algal biomass. The bio-crude thus obtained was reportedly having fuel properties close to that of the petroleum based heavy oil and had an energy value of 30-36 MJ/kg (42 MJ/kg for petroleum crude oil). Qualitative analyses of bio-crude oil have shown higher carbon compounds (C8-C17), phenolic compounds, carboxylic acids, amines, and aromatic compounds as the major components of bio-oil. The distribution of various products were 30-48% bio-oil, 20-40% gas, 3-8% solid residue and the balance consisted of value added products such as formate, acetate and ethanol dissolved in the aqueous phase. The outputs of the research will be beneficial in providing information in developing microalgae based biofuel technology.

Editorial: Recent Advancements in Algae-to-Biofuels Research: Novel Growth Technologies, Conversion Methods, and Assessments of Economic and Environmental Impacts

Sweet sorghum has become a promising alternative feedstock for biofuel production because it can be grown under reduced inputs, responds to stress more efficiently than traditional crops, and has large biomass production potential. A three-year field study was conducted to evaluate three cultivars of sweet sorghum as bioenergy crops in the Southeast United States (Fort Valley, Georgia): Dale, M81 E and Theis. Parameters evaluated were: plant density, stalk height, and diameter, number of nodes, biomass yield, juice yield, °Bx, sugar production, and theoretical ethanol yields. Yields were measured at 85, 99, and 113 days after planting. Plant fresh weight was the highest for Theis (1096 g) and the lowest for Dale (896 g). M81 E reported the highest stalk dry weight (27 Mg ha−1) and Theis reported the lowest (21 Mg ha−1). Theis ranked the highest °Bx (14.9), whereas M81 E was the lowest (13.2). Juice yield was the greatest for M81 E (10915 L ha−1) and the lowest for Dale (6724 L ha−1). Theoretical conservative sugar yield was the greatest for Theis (13 Mg ha−1) and the lowest for Dale (9 Mg ha−1). Theoretical ethanol yield was the greatest for Theis (7619 L ha−1) and the lowest for Dale (5077 L ha−1).

Biomass Energy from Revegetation of Landfill Sites

Citation: Jena U and Hoekman SK (2017) Editorial: Recent Advancements in Algae-to-Biofuels Research: Novel Growth Technologies, Conversion Methods, and Assessments of Economic and Environmental Impacts. Front. Energy Res. 5:2. doi: 10.3389/fenrg.2017.00002 Editorial: recent advancements in algae-to-Biofuels research: Novel Growth technologies, Conversion Methods, and assessments of Economic and Environmental impacts

Analysis of Solid and Aqueous Phase Products from Hydrothermal Carbonization of Whole and Lipid-Extracted Algae

While landfilling provides a simple and economic means of waste disposal, it causes environmental impacts including leachate generation and greenhouse gas emissions. Increasingly, revegetation is practiced on traditionally managed landfill sites to mitigate environmental degradation. It also provides a source of biomass for energy production. Biomass from landfill sites can be converted to bioenergy through biochemical and thermochemical processes. Selection of suitable biomass-producing plants (high-yielding crops), pretreatments (e.g., removal of lignin) and providing ideal conditions for the conversion processes (e.g., temperature and pressure) influence the quantity and quality of energy generated. This chapter provides an overview of the potential volumes of biomass produced from landfills and the various methods of biomass energy conversion.