Viscous Products Research Articles

New ways to improve the efficiency of railway transportation of viscous petroleum products

The paper proposes a new approach to solving the problem of increasing the economic efficiency of railway transportation of viscous petroleum fuels (fuel oils) at low air temperatures. The physical properties of fuel oils allow them to be obtained when poured into the tank of a tank wagon in a stratified state, when their density in the upper part of the tank is significantly less than in its lower part. This blocks the natural convection of hot fuel oil on the cold walls of the tank, and it cools only due to the molecular thermal conductivity which is very small. Upon cooling down, a relatively thin highly viscous layer forms on the inner walls of the tank of a tank wagon, which acts as a heat-insulating shell, and the bulk of it (more than 90%) retains high temperature and fluidity throughout the period of transportation. The thermal and hydrodynamic calculations were performed using modern computer technologies (the ANSYS 5.6 software package). The results obtained show that the need to heat up the fuel oil during unloading remains, but already requires significantly less time and heat energy. The proposed energy-saving technologies for the delivery of viscous petroleum products are especially relevant in Russia with its cold continental climate, long-haul transportation, and the current structure of the country’s wagon fleet. The value of the results obtained lies in the fact that the proposal can be implemented on tank wagons in circulation with minimal change to their design. The technology of operation of the drain equipment at unloading points will not change either.

Исследование нефтеемкости природных опоков Астраханской области

The article deals with the issues of studying the absorption capacity of oil and petroleum products (oil capacity) by a natural sorbent- the flask of the Central Kamennoyarsk field of the Astrakhan region. The study of oil capacity makes it possible to determine the possibility of using natural flakes as oil sorbents to collect oil and more viscous petroleum products from the surface of soils and hard coatings. In this work, the influence of the granulometric composition of the sorbent, the sorption temperature and the viscosity characteristics of oil and petroleum products on the oil capacity of the sorbent is studied. The regularities of the absorption capacity of natural flakes in the presence of oil, fuel oil, oil, gasoline and diesel fractions at temperature range from –5 to 40°C have been established. To determine the oil capacity, a static research method was used, in which the sorbent was not subjected to mechanical mixing during contact with the petroleum product. Thus, when testing sorbent fractions with particle sizes less than 1 and 2.5 mm it was stated that high oil capacity results (0.79-0.88 g/g) were achieved at temperature range from –5 and 20ºC in the presence of fuel oil and oil. The greatest sorption effect is achieved due to the influence of external adsorption and the adhesive action of high-viscosity petroleum products. A further increase in temperature to 40ºC reduces the viscosity of petroleum products and prevents the formation of a stable mixture with the sorbent. Relatively low values of the sorption capacity were obtained in the presence of watered oil. Regardless of the temperature, the oil capacity does not exceed 0.75 g/g. The collection of gasoline and diesel fuel is ineffective due to their low viscosity and high volatility.

A facile strategy for improving the hydrophobicity and photo-thermal conversion capability of biochar and its application in the absorption of hazardous chemicals and viscous oil

Biochar is considered as a promising adsorbent due to its unique porous structure, large surface area and lightweight nature. In this study, pomelo peel was used as raw material, and graphene oxide was introduced as a functional material. High-temperature carbonization was employed to achieve simultaneous carbonization of pomelo peel and thermal reduction of graphene oxide, resulting in the preparation of a porous sponge-like biochar with high hydrophobicity, thermal stability and photothermal conversion capability. This biochar was successfully applied to the efficient separation of various oil–water mixtures, demonstrating excellent cyclic adsorption stability. Furthermore, by harnessing its photothermal conversion effect, efficient absorption of viscous oil product was achieved. This study proposes a facile biochar preparation strategy that can expand its application in the field of oil spill emergency treatment and promote the utilization of agricultural waste.

Exploring the impact of the process parameters on the thermal treatment of viscous food fluids in a tube-in-tube heat exchanger

Thermal treatments are essential to abate the microbial load in food matrices and ensure food safety. Heat exchangers (HEs) are commonly adopted for the pasteurization of liquid foods, thanks to their simple structure and ease of use. In particular, tubular HEs are often employed with viscous fluids and products containing fibres and pieces. The aim of pasteurization is to ensure that every point of the product reaches and maintains the target temperature for an adequate amount of time. To this end, it is essential to guarantee uniformity and prevent portions of fluid from reaching an insufficient temperature, and others from being overheated. To evaluate the thermal treatment inside a tube-in-tube HE, computational fluid dynamics (CFD) was used to simulate a pilot plant. Three different fluids with shear-thinning temperature-dependent non-Newtonian behaviour were evaluated. A CFD simulation campaign was carried out reproducing, for each juice, the thermal treatment under different operating conditions. Then, the results were analysed with statistical techniques to evaluate the impact of each operating parameter on the treatment, highlighting how high viscosity greatly impacts the thermal treatment, resulting in lower average temperature and temperature uniformity, while causing an increase in the pressure drop. The results of the simulation campaign were also used to generate a reduced order model (ROM) of the device, that could be exploited to estimate the outcomes of a treatment both as averaged values on a section or at a specific point like “virtual sensors”. The ROM could be also adopted to design and evaluate alternative treatments by performing numerical optimization based on given objectives and constraints. Finally, as the ROM can be implemented in real-time, it could be used to monitor and control the functioning of food plants, detecting deviations from the expected conditions and possible failure conditions.

Impact of Storage Conditions of Yogurt Dry Ingredients on the Physicochemical Properties of the Final Product

This study investigated the impact of storage conditions of the ingredients for yogurt production on the rheological and physicochemical characteristics of the final fermented product. The novelty is the application of a special mix of milk protein concentrate and sodium caseinate for yogurt production. Separately exposing the protein mix powder and bacteria culture to 20 °C caused considerable changes in the obtained yogurt stiffness and the incubation times required to produce the gel due to a decrease in bacterial count. Minimal changes in bacteria viability were observed after storage at 5 °C. Lower temperature and shorter storage times increased yogurt firmness, viscosity, and storage modulus, resulting in a smoother and more viscous product. A linear correlation was found between yogurt firmness and water activity. Powders stored at lower temperatures and for shorter times produced yogurt with stronger texture and better water binding. Additionally, yogurt obtained from dry ingredients stored under these conditions required shorter incubation times. Storing the starter culture at 5 °C for at least 8 weeks had no significant effects on the physicochemical properties or incubation time requited to produce the final yogurt. This work highlights the importance of storage conditions of yogurt dry ingredients in maintaining the quality of the final product.

New approaches to the determination of organochlorine pesticides in food products and food raw materials

Introduction. The current methods for determining the residual amounts of organochlorine pesticides – 4,4-dichlorodiphenyltrichloromethylmethane (DDT) and its metabolites, hexachlorocyclohexane (HCH) (α, β, γ isomers) in food products and food raw materials, subject to mandatory declaration for their content, despite a fairly high sensitivity, are characterized by low measurement selectivity and are based on the use of obsolete equipment, time-consuming sample preparation. 
 Material and methods. In the work, the method of gas chromatography with mass spectrometric detection on a gas chromatograph “Khromatek-Kristall 5000.2” was used. Sample preparation was carried out by the method of matrix solid-phase dispersion, based on the destruction and dispersion of the analysed sample together with florisil in order to obtain a free-flowing dry mixture.
 Results. The effectiveness of the method has been proven by validation on 16 model samples of food products of animal origin of various compositions. The versatility of the analysis procedure is ensured by the systematization of food products according to their structural and mechanical properties into groups: liquid, having a finely dispersed structure and a high water content (group A); viscous and pasty products having a fine structure (group B); products of animal origin requiring grinding and dispersion (semi-solid and solid), having a high water and/or fat content, not free-flowing (Group B); dry products of animal origin (dried or freeze-dried), and/or free-flowing powdered products with a low water content that require wetting, grinding and dispersion (Group D). Ingredient composition (water, fat, protein, hydrocarbons) does not significantly affect the stability and reproducibility of the developed method.
 Limitations. The method has been tested and validated on samples of food products of animal origin. 
 Conclusion. The developed method for the determination of DDT and its metabolites, HCH (isomers α, β, γ), providing a range of measured concentrations (0.01–1.0 mg/kg) will make it possible to control the content of substances in all groups of food products of animal origin identified in the TR CU 021/11 “On food safety”, including products for baby food.

Amount of Fill Product Residues in Plastic Packagings for Recycling

Fill product residues in packagings are equivalent to product losses. They are washed out after sorting and before commencing recycling processes. Not much data have been published about how much fill product is still present in packagings dedicated for recycling. Results are often from laboratory trials. Therefore, several hundred packagings from a sorting plant of a dual system in Germany were analysed to determine the amount of fill product residues. Approximately 10 wt. % of highly viscous fill products in tubes were lost as residue. In the case of packagings that were easy to empty, such as cups, and in the case of low-viscosity fill products, such as water, less than 1 wt. % of the fill products remained in the packagings. The mean amount of residue in relation to clean packaging was 0.9 g residue in 1 g of packaging material (without residue) in tubes and 0.07 g in PET bottles. These values were significantly lower for low-viscosity fill products compared to high-viscosity fill products, as expected.

Effects of a naturally occurring caffeine product delivered orally on rate of caffeine absorption and associated metabolic parameters in the bovine neonate

A significant amount of published research has been conducted in the field of human medicine investigating the therapeutic effects of administering caffeine to infants. Consequently, caf­feine is very commonly used as a stimulant, particularly in the NICU. However, little work exists investigating the applica­tion of caffeine in bovine neonates, specifically those with low vigor. The study objectives were first to determine absorption rate and subsequent blood concentration of caffeine in calves administered a viscous oral product containing naturally oc­curring caffeine (Calf Perk®, TechMix LLC, Stewart, MN). The second objective was to determine if caffeine alters any associ­ated effects on metabolic variables of the calf such as circulat­ing glucose, insulin and NEFA concentrations.

Influence of disaccharide and monosaccharide on the rheological behavior of dry-heated alocasia starch under high pressure assisted treatment

High viscous products made with starch are of great scientific interest in the food, pharmaceutical, and cosmetic industries because they can be used to make creams and gels, as well as functional foods and nutritional products. But, obtaining a good quality highly viscous materials represent a technological challenge. In this present study, the effect of high-pressure treatment at 120 psi for different time interval on the mixture of dry-heated alocasia starch in presence of monosaccharide and disaccharide was studied. A flow measurement test on the samples revealed their shear-thinning behavior. With 15 min of high-pressure processing time, the dry-heated starch and saccharide mixtures displayed the highest viscosity. The dynamic viscoelasticity measurement showed that the storage and loss modulus was enhanced significantly after high-pressure treatment, and all pressure-treated samples showed a gel-like structure (G/>G//). In temperature sweep measurement, the rheological profile of storage modulus, loss modulus, and complex viscosity exhibited a two-stage pattern, i.e., first increased, then decreased, and their values were enhanced significantly after pressure treatment. The resultant highly viscous dry-heated starch and saccharide system have various functionalities in diverse food and pharmaceutical products.

Development of Value-Added Butter by Incorporating Whey Protein Hydrolysate-Encapsulated Probiotics.

The probiotic foods market is growing exponentially; however, probiotics' survivability and interaction with product attributes pose major challenges. A previous study of our lab developed a spray-dried encapsulant utilizing whey protein hydrolysate-maltodextrin and probiotics with high viable counts and enhanced bioactive properties. Viscous products such as butter could be suitable carriers for such encapsulated probiotics. The objective of the current study was to standardize this encapsulant in salted and unsalted butter, followed by storage stability studies at 4 °C. Butter was prepared at a lab-scale level, and the encapsulant was added at 0.1% and 1%, followed by physiochemical and microbiological characterization. Analyses were conducted in triplicates, and means were differentiated (p < 0.05). The viability of probiotic bacteria and the physicochemical characteristics of the butter samples with 1% encapsulant were significantly higher as compared to 0.1%. Furthermore, the 1% encapsulated probiotics butter variant showed a relatively higher stability of probiotics ratio (LA5 and BB12) than the control with unencapsulated probiotics during storage conditions. Although the acid values increased along with a mixed trend of hardness, the difference was insignificant. This study thus provided a proof of concept for incorporating encapsulated probiotics in salted and unsalted butter samples.

Understanding stable/unstable miscible A+B→C reaction front and mixing in porous medium

The transport phenomena of A + B → C type reactive miscible front undergoing radial displacement in a porous medium are numerically investigated. For a stable displacement when the viscosity of fluids A, B, and C is same, the dependence of various reaction characteristics on the Damköhler number (Da) is analyzed. The total reaction rate is found to be a non-monotonic function of time depending upon Da, while the total amount of product follows the temporal scaling ∝ t f ( D a ). The viscosity contrast in the system renders unstable flow and results in a hydrodynamic instability called viscous fingering. The effect of hydrodynamics on the reaction product formation is discussed. An insight into the reaction characteristics due to interaction of chemical reaction and instability is obtained for various log-mobility ratios R b and R c. It is observed that the onset of instability, as well as the mixing of the fluids, depends on whether the reaction generates a high or less viscous product or equivalently, the sign of | R b − R c |, keeping Rb fixed. Furthermore, the relation between the first moment of averaged reaction rate for stable and unstable displacement is influenced by the sign of | R b − R c | and Da. The coupling of convection and diffusion on the chemo-hydrodynamic instability is presented, and the existence of the frozen fingers in this reactive fluid system is reported. Our numerical results allow us to understand how instability and chemical reaction interplay to affect the reaction characteristics and the mixing of fluids.

Определение дисперсности в темных нефтяных средах

Properties of oil and petroleum products largely depend on the fractional and chemical composition, on the quantitative content of different components in them, their qualitative characteristics, as well as on the dispersed composition of the oil system. Examples of oil dispersed systems are given in accordance with their classification. The dispersed phase and its structure are considered on the basis of classical concepts as a complex structural unit consisting of a nuclear and layers surrounding it. The dispersion degree is defined by the forces of intermolecular interaction between the nucleus and layers of a complex structural unit, as well as between the layers. A great contribution to forming and stability of a complex structural unit is made by bonds based on spin-spin and spin-polarized interactions. The diamagnetic components of the system form a dispersion environment. The greater a dispersion, the stronger the molecular kinetic factors become, the more intensive the diffusion processes are, the sedimentation stability increases, and the physico-chemical processes at the phase boundary accelerate. Therefore, dispersion is one of the most important factors of oil dispersed systems that determine their properties (viscosity, flash and solidification temperatures, fractional composition, density). The study of changes in the dispersion of the system under various kinds of influences, determined by the size of the average diameter of the particles of the dispersed phase, makes it possible to identify the most favorable conditions for the implementation of technological processes during transportation, storage, processing, and ensuring environmental safety. The proposed photoelectrocolorimetric method for determining &#x0D; a mean diameter of particles of the dispersed phase of dark and viscous petroleum products differs from the well-known method in that it is carried out without diluting the sample, which could distort its dispersed composition. Besides, the sample optical density is determined in a thin fixed layer of a petroleum product due to a hard insert between the slides. The analysis methodology is described including a description of the device, a sequence of preparation and measurement, as well as processing of the results obtained.

Ease to Challenges in Achieving Successful Synthesized Schiff Base, Chirality, and Application as Antibacterial Agent

This study reports how to overcome the challenges experienced in achieving successful synthesized Schiff base via types of Schiff base (chiral and achiral), synthesis, nature of products, and its antibacterial applications. Schiff base is a versatile ligand which is useful in asymmetric reactions to prepare chiral catalysts. It is also used in symmetric reactions to prepare achiral compounds. In line with the achiral compounds, conventional (room temperature and refluxing) and microwave irradiation methods are the two main types of methods to synthesize achiral Schiff base as reported in this review. Among various experimental approaches, this study supports the green chemistry microwave approach to synthesize Schiff base because of its benefits environmental sustainability. Problems relating to the nature of products formed from the synthesized Schiff bases were examined and resolved. Herein, the products could either be solid (crystals, powder, and precipitate), oily, or viscous (sticky) products. Some familiar characterization techniques used to identify and confirm the successful syntheses of Schiff bases, such as solubility test, melting point (MP), Fourier transform infrared (FTIR), ultraviolet‐visible (UV‐Vis), and nuclear magnetic resonance (NMR, 1H NMR, and 13C NMR), were discussed. In addition, the antibacterial studies on Schiff base and corresponding metal complexes confirmed their biological relevance to the human.

Optimization of ingredients and processing parameters for the development ofCheddar cheese based beverage

The present study was carried out to develop Cheddar cheese based beverage by optimizing the level of ingredients and the processing parameters to meet the increasing consumer demand for functional foods. Cheddar cheese (5-6 months ripened) was used for the preparation. The effect of varying the Cheddar cheese to water ratios (1:1, 1:2 and 1:3) along with different type of emulsifying salts, TSC (tri-sodium citrate) and STPP (sodium tri-polyphosphate) and processing parameters like cooking time (4 &amp; 6 min) and stages of water addition (2 &amp; 3times) on the moisture, viscosity and sensory properties of the developed beverage were studied. At cheese to water ratio of 1:3fat separation was found to occur even after using tri-sodium citrate and sodium tri-polyphosphate as emulsifiers at all processing conditions. Cheese to water ratio of 1:1 resulted in highly viscous product. At cheese to water ratio of 1:2 it was found that the type of emulsifier used, cooking time and stages of water addition had a significant (p&lt;0.05) effect on the beverage properties. Acceptable quality cheese beverage was made at cheese: water of 1:2 with sodium tri-polyphosphate as an emulsifier when cooked for 4 minutes with water added at 2 stages. The resultant product showed acceptable moisture content of71.88+ 0.17%, viscosity of 2.04 + 0.06 Pa s at room temperature with good sensory scores and creamy mouthfeel.

Nutritional composition of Sacha inchi (Plukenetia volubilis) according to cooking method and its application as an elder‐friendly drink

SummarySacha inchi (Plukenetia volubilis) can be a great source of nutrition for the elderly since it contains great conditions of bioactive substances such as antioxidants and essential amino acids. Therefore, this study aimed to set up an optimal pretreatment method of Sacha inchi and to develop viscous beverage products for the elderly. As a result, roasting Sacha inchi had a significant effect on improving the essential amino acid content and antioxidant ability rather than raw and boiled one. However, because ageing threatens to choke older people even if they drink non‐viscous water, a viscous roasted Sacha inchi breeze was developed for the elderly. Therefore, it was confirmed that all thickening agents used in this study could be applied as elder‐friendly foods suitable for Korean Industrial Standards, and the regression equation for viscosity changes according to thickenrs concentrations was ‘Y = 75 312X−35.394’ for xanthan gum, ‘Y = 61 413X−201.33’ for locust bean gum, ‘Y = 4200.7X−7.2438’ for carrageenan, and ‘Y = 999.85X + 3.141’ for gum arabic. In conclusion, this study can help prevent suffocation and improve nutritional imbalance by developing viscous drinks using Sacha inchi for the elderly with weak oesophageal muscles.

The Influence of Viscosity on the Antimicrobial Activity of Simple Alcoholic-Based Hand Sanitizer for Infection of Covid-19 in Nigeria

Aim: This study was carried out to analyze and evaluate the influence of viscosity on the antimicrobial activity of simple alcoholic-based hand sanitizer preparations.&#x0D; Methods: The preparation of different viscosities of hand sanitizer was done by the introduction of carbomer to define its physicochemical stability. Two folds serial dilution of the test product using isopropyl alcohol and ethanol as alcohols and biocide efficiency to determine the antimicrobial activity using killing time assay were carried out.&#x0D; Results: The pH was adjusted to 7.29 and 7.11 respectively, which shows the neutrality of the products. More so, the pH of the two test products proved to be good and hence, stable. In terms of viscosity, it decreased as the concentration decreased at 0.07% for most of the organisms which indicated good antimicrobial activity on the bacterial and fungi strain used. However, concentrations of isopropyl-formulated test product were more effective than the ethanol-based product on the bacterial strains, with Pseudomonas aeruginosa having the highest percentage of microbial death at 92.5%. Although, the ethanol-based products showed higher antimicrobial activity against fungi strains than the isopropyl test product.&#x0D; Conclusion: Viscosity influences the activities of alcohol-based hand sanitizers since less viscous test product has a less concentration. Thus, more water denatures the proteins of the microorganism and limits the release of the active ingredient from the formulation. Sequel to this, viscosity enhancers like thickeners and gelling agents like carbomer should be used minimally in the formulation of these products.

Physicochemical, Morphological, Thermal, and Rheological Properties of Native Starches Isolated from Four Cultivars of Anchote (Coccinia abyssinica (Lam.) Cogn.) Tuber.

Anchote (Coccinia abyssinica (Lam.) Cogn) is a potentially important source of starch and an underutilized root and tuber crop indigenous to Ethiopia. In this study, the physicochemical, morphological, thermal, and rheological properties of native starches isolated from four cultivars of anchote tubers were studied and compared to potato and cassava starches, which were considered as references. The amylose content of anchote starches varied from 15.8–22.3%. The anchote cultivars showed different granule sizes, but all revealed a B-type crystalline structure, identical to potato starch. The phosphorus content of anchote starches ranged from 82–93 mg/100 g and was much higher than that of potato and cassava (60.3 and 5.8 mg/100 g, respectively). This characteristic could govern several functional properties of anchote starches, making them suitable for applications in different types of noodles, glucose syrups, and viscous products. The gelatinization temperature and enthalpy of anchote starches, which ranged from 60.97 °C to 69.33 °C and 16.87 to 18.38 J/g, respectively, were considerably different compared to potato and cassava starches. Significant variations were also observed among the pasting properties of starches from anchote cultivars. They showed a higher stability to heating and shearing, having higher TV (2046 to 2280 mPa·s) and lower BV (248 to 487 mPa·s) values, and a higher final viscosity (3409 to 3686 mPa·s) than potato and cassava, which are important characteristics in food processing and when high gel viscosity is required after cooling. Anchote starch gels exhibited rheological characteristics of true gels, showing much lower (tan δ)1 values and significantly higher viscoelastic moduli than those found in cassava and potato gels. The present study revealed significant differences among the physicochemical properties of anchote starches, depending on the cultivar, and demonstrated their promising potential in food product development and other industrial applications.

Comparison of the nutritional composition of raw, boiled, roasted Macadamia (F. Muell. Macadamieae) and its application as an elder-friendly food

The purpose of this study is to establish an optimal pretreatment method that can improve the nutritional quality of Macadamia, and to develop viscous beverage products for the elderly with dysphagia to help prevent suffocation and improve nutritional imbalance. As a result, roasting Macadamia had a significant effect on increasing the unsaturated fatty acid and mineral content (p < 0.01) rather than raw and boiled. Next, a thickening agent was added to develop viscous nut breeze using roasted Macadamia for the elderly, who could easily choke even if they drank water due to weakened esophageal muscles. Therefore, it was confirmed that all thickening agents used in this study can be applied as elder-friendly foods suitable for Korean Industrial Standards, and the regression equation for viscosity change according to thickening agent concentration was ‘Y = 62,136X + 29.821 (R2 = 0.9676)' for xanthan gum, ‘Y = 59,271X – 200.79 (R2 = 0.9542)’ for locust bean gum, ‘Y = 4,069X – 7.4643 (R2 = 0.9578)’ for carrageenan, and ‘Y = 900X + 3.6429 (R2 = 0.9589)’ for gum arabic. In conclusion, this study can help prevent suffocation and improve nutritional imbalance by developing viscous nut breeze beverage products using roasted Macadamia for the elderly with dysphagia, and can be used as basic data for the elder-friendly food industry in the future. Meanwhile, as in this study, studies should be continuously conducted to reduce the nutritional imbalance of the elderly by changing the intake methods of various nuts.

Determination of the load characteristics of single-screw pumps used at the enterprises of the agro-industrial complex

Single-screw pumps are widely used at enterprises of the agro-industrial complex, for example, in the food industry for pumping semi-viscous and viscous products, agriculture during drainage or irrigation of the territory. Hydraulic calculation of technological pipelines, which takes into account the characteristics of pumping equipment, is an important stage in the creation of food industry enterprises. In this article, the results of processing published experimental data are considered, according to which formulas for the dependence of the flow rate Q on the pressure drop ΔP for the studied single-screw pumps are obtained, and it is also revealed that this dependence is close to linear, as in plunger pumps. Experimental calculations made it possible to determine that the dependence of the flow rate Q on the rotor speed n is characterized by the volume of liquid pumped per revolution V1 and the initial rotor speed at which the movement of the liquid n0 begins. It is found that, in the general case, the values V1 and n0 depend on the pressure drop ΔP.

Co-Solvent Assisted Hydrothermal Liquefaction of Algal Biomass and Biocrude Upgrading

This study reports the hydrothermal liquefaction (HTL) of microalgae Spirulina platenesis in the presence of alcohol or formic acid co-solvents. HTL runs are performed in a 1.8-L batch reactor at 300 °C using an alcohol (methanol and ethanol) or formic acid co-solvent. Consequently, hydrodeoxygenation (HDO) of resultant algal biocrude is performed at 350 °C for 2 h under high hydrogen pressure (~725 psi) using the Ru/C catalyst. The HTL results are compared with the control HTL run performed in water only. The results of the study show that the addition of co-solvents leads to a 30–63% increased biocrude yield over the control HTL run. Formic acid results in a 59.0% yield of biocrude, the highest amongst all co-solvents tested. Resultant biocrudes from formic acid-assisted and ethanol-assisted HTL runs have 21.6% and 3.8–11.0% higher energy content, respectively, than that of the control run. However, that of the methanol-assisted HTL results in biocrude with 4.2–9.0% lower energy density. Viscosity of biocrude from methanol- or ethanol-assisted HTL is higher than the control HTL but formic acid-assisted HTL results in a less viscous biocrude product. In addition, the HDO study leads to a 40.6% yield of upgraded oil, which is characterized by a higher net energy content and lower O/C and N/C ratios when compared to the initial HTL biocrude.