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Grindelia squarrosa, known as gumweed, is a shrub that grows in arid lands in North America with up to 8% biocrude (or bio-oil) content that can be extracted by using a common solvent extraction method. This solvent-extracted biocrude (SEB) has nearly 24 wt% oxygen, which is not suitable for direct combustion as a bio-oil or biodiesel. In this study, supercritical water (SCW) upgrading is used to reduce the oxygen of the SEB and increase the fuel value by creating lighter oil fractions. Treatment for 30 min reduces the oxygen content from 24.1 ± 1.6 (for raw SEB) to 7.2 ± 0.7%, 7.1 ± 0.4%, and 6.9 ± 0.6% at 380, 400, and 420 °C respectively. The addition of palladium on carbon (Pd/C) catalyst at 400 °C further reduces the oxygen content to 4.8 ± 0.7%. This removal in oxygen content is shown in the reduction of carboxylic acid compounds in the oils. Without having to use hydrogen, such as with the traditional hydrodeoxygenation process, the SCW upgrading has rather high energy yields for the oils which all have higher heating values between 41.0 and 42.8 MJ kg−1 (with no significant effect of temperature or catalyst). Treatment at 400 °C had the highest energy yield at 76.4 ± 1.7%, and treatment with the Pd/C catalyst at 400 °C had the lowest at 61.4 ± 2.8%. These energy yields, higher heating values, and low oxygen contents show that SCW can effectively be used to convert gumweed-derived SEB into a valuable bio-oil.

The aim of this research was to evaluate the technoeconomic prospect of hydrochar production through co-hydrothermal carbonization of coal waste (CW) and food waste (FW). A process flow diagram was developed that considered seven reactors, six pumps, and other necessary equipment for producing 49,192 kg/h hydrochar. Three different cases were considered for the economic analysis. Case II considered both CW and FW transportation cost while cases I and III considered only FW and only CW transportation, respectively. The economic analysis revealed the break-even costs to be $62.24 per ton for case I, $69.90 per ton for case II, and $60.26 per ton for case III. The fixed capital investment (FCI) was $11.4M for all the cases while total capital investment (TCI), working capital (WC), and manufacturing costs were higher for case II compared to cases I and III. A sensitivity analysis examined the effect of nine different variables on the break-even cost. The raw materials’ cost as well as their transportation costs significantly affected the corresponding break-even cost. Additionally, increasing the hydrochar production capacity has drastically decreased the break-even cost. However, the analysis also revealed that excessive increase of production capacity can have negative impact on the process economics.

Torrefaction is a promising technology to improve fuel properties of biomass. However, torrefied char does not show densified energy content compared with coal and typically requires densification such as pelletization. Several key parameters including pelletization and torrefaction conditions were investigated in order to determine the effects on energy density of torrefied char pellets. In this study, multivariate analyses were performed using three independent variables, torrefaction temperature, pelletization temperature, and pelletization pressure; and five dependent variables: mass density, durability, volume expansion, higher heating value (HHV), and energy density (ED). The variation and correlation of the dependent variables were evaluated using principal component analysis (PCA). Additionally, multivariate linear regression was performed to correlate independent variables and dependent variable responses using an adjusted sum of squares method and a two-sided, 90% confidence interval for the mean response; the model was fitted with statistically significant linear, quadratic, and interaction terms. The statistical analysis showed that all independent parameters are statistically significant for ED with the largest model variation from experimental data being 1.44%. Response curve of the regression analysis showed that mass density, HHV, and energy density model have the highest output predictability with higher R2 values of 95.3%, 98.1%, and 74.1%, respectively.

Salmon lice (Lepeophtheirus salmonis) infestations on Salmonids (Salmo salar) in cages has brought Norwegian aquaculture to a stable production since 2012. Many chemotherapeutic , chemical, and mechanical approaches have been used to control the sea lice attack. Unfortunately, sea lice have developed resistance against chemotherapeutic treatments and other approaches are either not considered ecofriendly or effect fish health. Biological control is deploying cleaner fish in cages to combat the sea lice. Lumpfish (Cyclopterus lumpus) is of commercial interest as a cleaner fish since it can be deployed at age of 4 months. The complicated first feeding phase and a lack of functional feeding protocols are the major barriers to large-scale lumpfish cultivation. The current study aimed to contribute to the optimization of start-feeding regimes for lumpfish larvae in commercial farming. This was accomplished by comparing the effects of various start-feeding diets on the growth and survival of fish larvae. In addition to this development of lipids and fatty acids in lumpsucker larvae in relation to different feeding regimes was studied. Five feeding regimes were used in the experiment where lumpsucker larvae were fed from 2days post hatch to 35 dph. One group of larvae were fed with enriched artemia which were then weaned to formulated diet (FD). Second group were initially fed with copepods and then ultimately weaned to FD. Third group had Cirripedia initially and then weaned to FD. Fourth group had three types of feed initially copepods , then Cirripedia and then FD. Fifth group were fed with formulated diet firstly with small pellets(150nm) and then with large pellets (300nm). Larvae fed with Artemia had best growth and survival as compared to other feeding regimes. Total lipid content and fatty acid content was highest in Art larvae initially and decreased on weaning to formulated diet but still significant. Artemia had significant amount of omega 3 and omega 6 fatty acids contributing to good growth and survival. Until 35 dph lipid content went steady in Art larvae. Lipidomics revealed that several lipid and fatty acid species are correlated either negatively or positively. The results clearly show the importance and responses of certain fatty acids in starting feed and can be helpful in optimizing start-feed of lumpsucker larvae.

The aims of this work were to quantify chemical states associated with the pH, dissociation constants, and pH at point of zero charge (pHPZC) of hydrochar and to quantify the acidic functional groups on hydrochar surface. Hydrochars from cellulose and wood treated at 180, 220, and 260 °C with 30 min residence time were produced. Boehm titration was applied to analyze acidic functional groups and dissociation constants on hydrochar surfaces. FTIR spectroscopy was used to identify the functional groups qualitatively. The results of this study indicate that hydrochar becomes more acidic due to a larger number of acidic functional groups on the hydrochar surface with the increase of hydrothermal carbonization (HTC) temperature. The total number of acidic functional groups increased from 20.5 ± 0.3 μmol/g to 1267.9 ± 22.5 μmol/g and 576.6 ± 7.8 μmol/g to 680.8 ± 18.8 μmol/g for cellulose and wood, respectively.

Co-Hydrothermal Carbonization (Co-HTC) was performed on a blended feedstock of coal and miscanthus. The main goal of this work was to evaluate the synergistic effects of miscanthus on coal during Co-HTC. Fuel quality was assessed for all hydrochars by evaluating mass yields, energy content, ultimate analysis, and proximate analysis. Calculation of combustion parameters showed experimental ignition and burnout indices of Co-HTC 260 °C hydrochar were 29.0% and 26.5% lower than theoretical, non-interacting indices, respectively. Hydrochars shared the benefits of low sulfur and low ash content of miscanthus but maintaining higher energy content of coal. Hydrochars produced at 260 °C had energy contents as high as coal (27.3 ± 0.6 MJ kg − 1 ) and 73% less ash content and 74% less sulfur than raw coal as a result of the more acidic environment produced by miscanthus decomposition. Furthermore, hydrochars were homogeneous as miscanthus-derived hydrochar was formed on coal surface according to SEM imaging and verified by the reduced pore width from nitrogen adsorption. Co-HTC hydrochars were pelletized in a single-press pellet press. Both mass and energy densities of Co-HTC pellets were increased with the increase of Co-HTC temperature. For instance, energy densities of pelletized Co-HTC hydrochars were increased to 32.4 GJ m − 3 , whereas HTC coal contains energy density of 28 GJ m − 3 .

Each year the pulp and paper industries generate enormous amounts of effluent treatment sludge. The sludge is made up of various fractions including primary, secondary, deinked, fiber rejects sludge, etc. The goal of this study was to evaluate the fuel properties of the hydrochars produced from various types of paper mill sludges (PMS) at 180 °C, 220 °C, and 260 °C. The hydrochars, as well as the raw feedstocks, were characterized by means of ultimate analysis, proximate analysis, moisture, ash, lignin, sugar, and higher heating value (HHVdaf) measurements. Finally, combustion indices of selected hydrochars were evaluated and compared with bituminous coal. The results showed that HHVdaf of hydrochar produced at 260 °C varied between 11.4 MJ/kg and 31.5 MJ/kg depending on the feedstock. This implies that the fuel application of hydrochar produced from PMS depends on the quality of feedstocks rather than the hydrothermal carbonization (HTC) temperature. The combustion indices also showed that when hydrochars are co-combusted with coal, they have similar combustion indices to that of coal alone. However, based on the energy and ash contents in the produced hydrochars, Primary and Secondary Sludge (PPS2) could be a viable option for co-combustion with coal in an existing coal-fired power plant.

Co-Hydrothermal Carbonization (Co-HTC) is a thermochemical process, where coal and biomass were treated simultaneously in subcritical water, resulting in bulk-homogenous hydrochar that is carbon-rich and a hydrophobic solid fuel with combustion characteristics like coal. In this study, technoeconomic analysis of Co-HTC was performed for a scaled-up Co-HTC plant that produces fuel for 110 MWe coal-fired power plant using Clarion coal #4a and miscanthus as starting feedstocks. With precise mass and energy balance of the Co-HTC process, sizing of individual equipment was conducted based on various systems equations. Cost of electricity was calculated from estimated capital, manufacturing, and operating and maintenance costs. The breakeven selling price of Co-HTC hydrochar was $117 per ton for a 110 MWe. Sensitivity analysis indicates that this breakeven selling price could be as low as $106 per ton for a higher capacity plant. Besides plant size, the price of solid fuel is sensitive to the feedstock costs and hydrochar yield.