Small Batch Reactor Research Articles

Safety Design Criteria for the Emergency Discharge of Hazardous Substances in Small and Medium-Sized Polystyrene Polymerization Batch Reactor Processes: Case Study of the South Korean Chemical Industry

In small and medium-sized chemical plants, explosions constantly occur owing to runaway reactions because of equipment defects or human errors and so on. Accordingly, in this study, based on a case study of an explosion accident in a polystyrene reactor in South Korea, the dis-charge capacity of hazardous substances during a runaway reaction is reviewed and a method for safely disposing of hazardous substances is proposed. Using an acceleration rate calorimeter, the maximum temperature rise rate during the polystyrene reaction was determined, and it was determined that 355,643 kg/h can flow during a runaway reaction. A 30-inch header size was then selected to consider maximum flow rate, and two 81.4 m2 heat exchangers were selected to completely condense the hazardous substances. As a result, the facilities at the workplace were configured to condense all hazardous substances and discharge them into the atmosphere. If this method is used, it is believed that the lives of workers can be protected by preventing fires and explosions in small and medium-sized chemical plants in which runaway reactions may occur.

MOF-199 and Ni-BTC: Synthesis, Physicochemical Properties, and Catalytic Activity in Oxidation of 5-Hydroxymethylfurfural

Platform chemical 2,5-furandicarboxylic acid (FDCA) has potential applications to replace petroleum-based chemicals. Metal Organic Framework (MOF) can be used as a catalyst to oxidize 5-hydroxymethylfurfural (HMF), producing FDCA. MOF-199 and Ni-BTC were synthesized using solvothermal method with trimesic acid (benzene 1,3,5-tricarboxylic acid/H3BTC) as a linker and Cu or Ni as a metal nod. The physical and chemical properties of catalysts were discovered through characterization using X-ray Diffraction (XRD), Fourier Transform Infra Red (FT-IR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy - Energy Dispersive X-ray (SEM-EDX), and Ammonia Temperature-programmed Desorption (NH3-TPD). FDCA and its intermediate compounds were produced by converting HMF to FDCA in a small glass batch reactor. The yields of products were then determined by High-Performance Liquid Chromatography (HPLC). HPLC results indicated that there was no DFF (2,5-diformylfuran) signal, indicating that FDCA was formed by FFCA (5-formylfuroic acid) and HMFCA (5-hydroxymethylfuroic acid) formation reaction pathway. The maximum conversion (71%) was obtained using Ni-BTC as a catalyst at 130 °C for 5 h, with FDCA yield of 61.8%. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Oxidation of 5-hydroxymethylfurfural into 2,5-furandicarboxylic acid over CuO and NiO modified natural sourced hierarchical ZSM-5

The platform molecule 2,5-furandicarboxylic acid (FDCA) has potential applications. FDCA can be synthesized through the oxidation of 5-hydroxymethylfurfural (HMF). In this study, HMF oxidation to FDCA was conducted over ZSM-5-based catalysts from natural sources. ZSM-5 was impregnated with CuO and NiO oxide metals to increase their acidity and oxidizing ability. Characterization of the catalyst utilizing x-ray diffraction (XRD), infrared spectrophotometer (FT-IR), scanning electron microscopy-energy dispersive x-ray (SEM-EDX), Brunauer-Emmet-Teller (BET) surface area analysis, and temperature-programmed desorption of ammonia (NH3-TPD) led to the discovery of its physicochemical characteristics. The results showed that synthesized ZSM-5 had hierarchical pores with a surface area of 123.58 m2/g. Impregnation with CuO and NiO increased the acidity by 22.5 and 3.04 % for CuO/ZSM-5 and NiO/ZSM-5, respectively. In a small glass batch reactor, HMF was converted to FDCA, and the products were analyzed using High-Performance Liquid Chromatography (HPLC) to determine the yield of FDCA and the intermediate compounds, such as 5-hydroxymethylfuroic acid (HMFCA), 5-formylfuroic acid (FFCA), and 2,5-diformylfuran (DFF). HPLC results showed no DFF signal, indicating the formation of FDCA from HMF through HMFCA and FFCA. The highest conversion (99.2 %) was obtained using a NiO/ZSM-5 catalyst at a temperature of 130 °C for 4 h, with FDCA yield of 88.9 %.

The effect of adding wood and temperature on the carbonization of chicken manure and the properties of biochars

The paper presents characterization of chicken manure and mixture of chicken manure (CM) and beech wood (WB) carbonization at 450 and 600 °C. Experiments were carried out in small scale batch reactor. The obtained results indicate that increase in the amount of beech wood in the pellets caused increase in fixed carbon content and also affected increase in the calorific value of biochar. The results show that biochar obtained in the carbonization process of chicken manure cannot be used for the barbecue charcoal production, which is caused by low Cfix and high ash content. Because of this, adding wood may be a good solution for the carbonization process. Experimental investigation showed that carbonization of pellets consisting of CM50 % and CM25 % lead to obtained biochar which meets standards for briquette barbecue production. Experimental results showed the possibility of using pyrolysis gases for energy purposes. Carbonization in different temperatures lead to production of pyrolysis gas mixtures with calorific value higher than the energy demand of the process. Moreover obtained energy contained in gases can cover the part of the heat demand of the farm. Analysis of heavy metals content showed that biochars meet the standards defined by the International Biochar Initiative.

Metabolic multireactor: Practical considerations for using simple oxygen sensing optodes for high-throughput batch reactor metabolism experiments.

We present a system for carrying out small batch reactor oxygen consumption experiments on water and sediment samples for environmental questions. In general, it provides several advantages that can help researchers achieve impactful experiments at relatively low costs and high data quality. In particular, it allows for multiple reactors to be operated and their oxygen concentrations to be measured simultaneously, providing high throughput and high time-resolution data, which can be advantageous. Most existing literature on similar small batch-reactor metabolic studies is limited to either only a few samples, or only a few time points per sample, which can restrict the ability for researchers to learn from their experiments. The oxygen sensing system is based very directly on the work of Larsen, et al. [2011], and similar oxygen sensing technology is widely used in the literature. As such we do not delve deeply into the specifics of the fluorescent dye sensing mechanism. Instead, we focus on practical considerations. We describe the construction and operation of the calibration and experimental systems, and answer many of the questions likely to come up when other researchers choose to build and operate a similar system themselves (questions we ourselves had when we first built the system). In this way, we hope to provide an approachable and easy to use research article that can help other researchers construct and operate a similar system that can be tailored to ask their own research questions, with a minimum of confusion and missteps along the way.

Debromination of Waste Circuit Boards by Reaction in Solid and Liquid Phases: Phenomenological Behavior and Kinetics

The debromination of waste circuit boards (WCBs) used in computer motherboards and components has been studied with two different pieces of equipment. Firstly, the reaction of small particles (around one millimeter in diameter) and larger pieces obtained from WCBs was carried out with several solutions of K2CO3 in small non-stirred batch reactors at 200-225 °C. The kinetics of this heterogeneous reaction has been studied considering both the mass transfer and chemical reaction steps, concluding that the chemical step is much slower than diffusion. Additionally, similar WCBs were debrominated using a planetary ball mill and solid reactants, namely calcined CaO, marble sludge, and calcined marble sludge. A kinetic model has been applied to this reaction, finding that an exponential model is able to explain the results quite satisfactorily. The activity of the marble sludge is about 13% of that of pure CaO and is increased to 29% when slightly calcinating its calcite at only 800 °C for 2 h.

Epoxidation of methyl oleate over various amorphous Ti–SiO2 catalysts

The epoxidation reaction of the vegetable oil derivative methyl oleate with tert-butyl hydroperoxide in the presence of amorphous Ti–SiO2 catalysts prepared by different methods using various silica sources was carried out. The reaction conditions were optimized. The relation between the properties of the catalysts such as specific surface area as well as titanium dispersion and the catalytic performance was in focus of the investigation. Based on the catalytic results in small batch reactors, the reaction was scaled up in a larger 4 L batch-reactor. Thereby similar conversions and selectivities were obtained in comparison with the small scale experiments.

Rapid start-up of autotrophic shortcut nitrification system in SBR and microbial community analysis

ABSTRACT Shortcut nitrification is crucial for application of autotrophic nitrogen removal which is beneficial for treating carbon-limited wastewater. In this experiment, rapid start-up of autotrophic shortcut nitrification system was studied in a small sequencing batch reactor (SBR) built in laboratory with intermittent aeration operation mode. The influent was artificially simulated inorganic domestic wastewater (the ammonium nitrogen concentration was 35.19–57.54 mg/L), the pH value was 7.6–7.8, the hydraulic loading was 1L, the operating temperature was 24.3–28.3 °C, and the dissolved oxygen (DO) was 2–4 mg/L and 0.5–0.9 mg/L at the stage of complete nitrification sludge domestication and shortcut nitrification sludge domestication. High-throughput sequencing technology was used to analyse the composition and changes of microbial populations in sludge. The experimental results showed that on the 24th day of the experiment, shortcut nitrification was started successfully, the accumulation rate of nitrite was 81.63% and the removal efficiency of ammonium nitrogen was 99.25%; the richness of the main denitrifying bacteria phylum Proteobacteria increased from 30.21% to 42.85%; the richness of Nitrosomonas (ammonia oxidizing bacteria, AOB) increased from 0.37% to 22.43%, and at the species level, AOB was the salt-tolerant bacteria Nitrosomonas. europaea; the richness of Nitrospira (nitrite oxidizing bacteria, NOB) decreased from 2.59% to 0.47%.

Synthesis and characterization of Cu(OH)2-NWs-PVA-AC Nano-composite and its use as an efficient adsorbent for removal of methylene blue

The present study focused on the synthesis of copper hydroxide nanowires decorated on activated carbon (Cu(OH)2-NWs-PVA-AC). The obtained Cu(OH)2-NWs-PVA-AC Nano-composite was distinguished by XRD, SEM, EDX, BET, FTIR and XPS respectively. Besides, different variables such as solution pH, and initial dye concentration, contact time, and temperature were performed on the adsorption efficiency of MB in a small batch reactor. Further, the experimental results are analyzed by various kinetic models via PFO, PSO, intra-particle diffusion and Elovich models, and the results revealed that among the kinetic models, PSO shows more suitability. In addition, different adsorption isotherms were applied to the obtained experimental data and found that Langmuir–Freundlich and Langmuir isotherm were best fits with the maximum adsorption capacity of 139.9 and 107.6 mg/g, respectively. The Nano-composite has outstanding MB removal efficiency of 94–98.5% with a span of 10 min. and decent adsorption of about 98.5% at a pH of 10. Thermodynamic constants like Gibbs free energy, entropy, and enthalpy were analyzed from the temperature reliance. The results reveal the adsorption processes are spontaneous and exothermic in nature. The high negative value of ΔG° (− 44.11 to − 48.86 kJ/mol) and a low negative value of ΔH° (− 28.96 kJ/mol) show the feasibility and exothermic nature of the adsorption process. The synthesized dye was found to be an efficient adsorbent for the potential removal of cationic dye (methylene blue) from wastewater within a short time.

Debromination of tetrabromobisphenol A in aqueous amine solutions under hydrothermal conditions

Tetrabromobisphenol A (TBBPA) powder was subjected to an aqueous amine solution in a small bomb-type batch reactor at temperatures from 447 to 553 K and pressures from 0.79 to 6.4 MPa. The effectiveness of aqueous amine solutions under hydrothermal conditions was examined for debromination of TBBPA, which is a brominated flame retardant commonly contained in printed circuit boards. The amines tested were methylamine, dimethylamine and trimethylamine. Compared to aqueous ammonia and aqueous sodium hydroxide solutions, all the amine solutions tested were more effective. For instance, the 89% debromination of the initial bromine contained in TBBPA was recovered by a 0.6 mol/kg aqueous methylamine solution at 533 K in 20 min. The debromination of TBBPA was accelerated with increasing reaction temperature and amine concentration. The four major products, 2,6-dibromophenol, 2-bromophenol, phenol and 2,6-dibromo-4-(1-methylethenyl)phenol, were detected by GCMS and the three former products were quantified by HPLC. According to the product distributions over time, a primary pathway of TBBPA debromination was proposed, in which the cleavage of a carbon-carbon bond initially took place, followed by debromination. The debromination reaction in an aqueous methylamine solution under hydrothermal conditions was described by pseudo first order reaction kinetics, and the activation energies changed at 473 K, and that above 473 K was much smaller than that in pyrolysis reported in the literature. The debromination rate constants at 473 and 533 K were proportional to methylamine concentration up to 0.3 mol kg−1, and those increased gradually above the temperature. The authors proposed debromination of TBBPA in an aqueous amine solution under hydrothermal conditions as a new debromination method due to relatively fast reaction rates and recovery of bromine as bromide ion.

Low temperature oxidation of heavy oil in oxygen-reduced air: Effect of pressure and oxygen content on heat release

Air injection for in situ combustion (ISC) and air injection assisted cyclic steam stimulation (AACSS) techniques have a good application prospective in the development of heavy oils, while the explosion risk in the process of air injection is of great concern and has restricted the application of the technology. So that injection of oxygen-reduced air has been proposed to eliminate and control the explosion of oil/gas mixture with air. In this study, low-temperature oxidation experiments of heavy oil samples were conducted using a small batch reactor under the pressure of 5–15 MPa and oxygen content of 5%–15% at 225 °C in order to investigate the effect of oxygen content and pressure on the reaction rate and heat release during oxidation of heavy oil with oxygen-reduced air. The variations of temperature and pressure during the oxidation reaction were measured in the experiment, and the explosion phenomena of heavy oils were observed in the air with high oxygen contents (oxygen content more than 15%). The reaction rate and the exothermic heat of the reaction were calculated based on the pressure and temperature curves and using an improved heat loss model. The experimental results showed that reducing the oxygen content (e.g. reduced oxygen less than 10%) in air can effectively prevent the explosion of oil-gas mixtures, and the reaction rate and heat release during heavy oil oxidation are linearly proportional to pressure and oxygen content in the injected air when oil is in excess. The results of this study indicate that the heat generated in oil oxidation, which is important for the ISC and AACSS processes, can be controlled by pressure and oxygen content of the injected air, which can lay a good foundation for the oxygen-reduced air injection technique, especially for its application in deep heavy oil reservoirs, in which injection of oxygen-reduced air at high pressure can offset the effect of low oxygen content on heat release.

Experimental study on thermal cracking reactions of ultra-heavy oils during air injection assisted in-situ upgrading process

In-situ upgrading (ISU) via down-hole heating can be an effective technique for exploitation of heavy oil reservoirs. In order to increase the heat transfer rate and reservoir energy, air or gas injection assisted in-situ upgrading process (AAISU) has been proposed. In the AAISU process, and also in the traditional in-situ combustion (ISC) process, complex thermal cracking reactions of heavy oils occur along with low temperature oxidation (LTO) in the presence of air or oxygen at high pressure conditions. In comparison with the conventional oil cracking or pyrolysis in refinery (without or with less oxygen), it has been concerned that low temperature oxidation of oil components during air injection may have some impacts on their cracking reactions. In this study, thermal cracking experiments of ultra-heavy oils in small batch reactor as well as thermogravimetry analysis (TGA) experiments have been conducted under high pressure in the presence of air and nitrogen to simulate the AAISU process. The starting temperature for cracking, the products of cracking reactions, reaction rate, and the influence of temperature and pressure on reaction kinetics have been investigated in order to reveal the influence of LTO on cracking reaction and to clarify the confusions. The experimental results demonstrated that the presence of air has some kind negative effect on the cracking of oils compared with that in the presence of nitrogen. For a typical ultra-heavy oil, the minimum starting temperature for cracking is around 350 °C in the presence of air at 3.2 MPa for a reaction time of over 30 days, while the starting temperature is around 325 °C when nitrogen is present. Less light oil components produced and lower cracking reaction rate (about 20–30%) were observed when air was present in comparison with that of nitrogen at the same pressure. That means higher activation energy is required to activate the thermal cracking reaction of oils when air or LTO reactions are involved.

Investigating the Effect of Processing Parameters on the Products of Hydrothermal Carbonization of Corn Stover

Corn stover is an abundant and underused source of lignocellulose waste biomass that can be transformed into a high-quality energy resource using hydrothermal carbonization (HTC). This investigation has focused on the effect of processing parameters on the products of HTC—namely solid fuel or hydrochar and liquid and gas fractions. HTC was conducted in a temperature-controlled small batch reactor with corn stover and deionized water under oxygen-free conditions obtained by pressurizing the reactor headspace with nitrogen gas. The properties of the hydrochar and liquid and gas fractions were evaluated as a function of the process temperature (250–350 °C), residence time (30–60 min) and biomass/water ratio (0.09–0.14). Central composite design modules in a response surface methodology were used to optimize processing parameters. The maximum mass yield, energy yield and high heating value (HHV) of the hydrochar produced were 29.91% dry weight (dw), 42.38% dw and 26.03 MJ/kg, respectively. Concentrations of acetic acid and hydrogen gas were 6.93 g/L and 0.25 v/v%, respectively. Experimental results after process optimization were in satisfactory agreement with the predicted HHV. The optimal HTC process parameters were determined to be 305 °C with a 60 min residence time and a biomass/water ratio of 0.114, yielding hydrochar with a HHV of 25.42 MJ/kg. The results confirm the feasibility of an alternative corn stover management system.

Micro-structured copper and nickel metal foams for wastewater disinfection: proof-of-concept and scale-up

It is necessary to disinfect treated wastewater prior to discharge to reduce exposure risks to humans and the environment. The currently practiced wastewater disinfection technologies are challenged by toxic by-products, chemicals and energy demand, a range of effectiveness limitations, among other concerns. An effective, eco-friendly, and energy-efficient alternative disinfection technique is desirable to modernize and enhance wastewater treatment operations. Copper and nickel micro-structured metal foams, and a conventional copper mesh, were evaluated as disinfecting surfaces for treating secondary-treated wastewater contaminated with coliform bacteria. The micro-structured copper foam was adopted for scale-up study, due to its stable and satisfactory bactericidal performance obtained over a wide range of bacterial concentrations and metal-to-liquid ratios. Three scales of experiments, using two types of reactor designs, were performed using municipal wastewater to determine the optimal scale-up factors: small lab-scale batch reactor, intermediate lab-scale batch reactor, and pilot-scale continuous tubular reactor experiments. The performance was evaluated with the aim of minimizing metal material requirement with respect to bactericidal efficiency and leaching risks at all scales. Copper foam, at or above optimal conditions, consistently inactivated over 95 % of total coliforms, fecal coliforms and E.coli in wastewater at various scales, and leachate copper concentrations were determined to be below Canadian guideline values for outfall. This study successfully implemented the “structure” strategy of process intensification, and opens up the possibility to apply micro-structured copper foam in a range of other water disinfection systems, from pre-treatment to point-of-use, and should thus become a topic of further research.

Experimental and analytical study of oxygen consumption during air injection in shale oil reservoirs

AIP (air injection process) is applied as an EOR (Enhanced oil recovery) method in conventional oil reservoirs, while the implementation of AIP in shale oil reservoirs has rarely been studied. The thermal effect of AIP in shale oil reservoirs is insignificant considering its low air injectivity, and the main challenge is whether the produced oxygen concentration at the production well can be reduced below 10% to avoid the potential safety hazards. In this paper, an analytical method was proposed to estimate the produced oxygen concentration during AIP, where the oxygen reaction rate was measured by the SBR (small batch reactor) experiments. In the SBR tests, a constant oxygen reaction rate was observed at a corresponding reservoir temperature. A higher reservoir temperature resulted with greater oxygen consumption. The air flooding tests were conducted with shale core and the proposed analytical method was validated by the air flooding tests. The analytical method was further applied to investigate the AIP feasibility in the air flooding tests. The results indicate that a core needs to be a longer than 0.132 m, or the injection pressure is lower than 2.68E + 06 Pa (388.70 psi), to satisfy the produced oxygen concentration requirement for AIP. This study can explore the potential of air injection in developing shale oil reservoirs and provide insights to the AIP projects in field level.

Kerosene Like Fuel Characteristics from Municipal Solid Plastics Waste Pyrolytic Oil for Domestic Purposes

The aims of the research are to characterized pyrolytic oil as fuel and utilize it for heating purpose. The pyrolytic oil was characterized to decide whether this oil can be used as fuel for the desired application or not. The highest pyrolytic fuel yield of about 67.48% w/w was obtained from converting of 3000 g of plastic waste at pyrolysis time, topt. of 240 minutes and a pyrolysis temperature of 360 °C in a small pilot-scale batch reactor. The characteristic of pyrolytic fuel had an average value of density and viscosity were 771 kg/m3, 1.031 cSt, respectively. The combustion quality as other characteristics of the fuel was obtained as heating value, flash point and auto-ignition point of 37.996 MJ/kg, 48 °C and 240 °C, respectively. The similar functional groups of pyrolytic oil and commercial kerosene fuel were found in Fourier-transform infrared spectroscopy (FTIR) spectrum. This pyrolytic oil provided a higher flame temperature of 1300 °C and a higher thermal efficiency of 33% upon utilized as fuel using a modified pressurized cook stove. These pyrolytic oil’s parameters are close to the standard values of the kerosene fuel.

Evaluation of the removal of total phosphorus from sanitary effluent by Chlorella vulgaris in a small batch photobioreactor

The search of the scientific community for efficient and cheap technologies for the treatment of wastewater in Brazil continues being a challenge, mainly in the effort to encourage the government, responsible for the application and proliferation of these technologies. The release of contaminated effluent without treatment in the aquatic bodies leads to the degradation of these environments, what requires the reuse of these waters, facing environmental sustainability. In this context, microalgae establish a promising alternative, once the main attribute of algae culture in wastewater is its ability to efficiently assimilate organic carbon and inorganic nutrients from wastewater to achieve a clean effluent with efficient nutrient removal, besides a biomass production, accumulation of lipids, which can be converted into biodiesel. Assuming the important role of photosynthetic CO2 fixation, which helps to mitigate the alarming effects of the release of greenhouse gases into the atmosphere. The main objective of this work was to evaluate the capacity of the microalga Chlorela vulgaris in the removal of phosphorus from the sanitary sewage collected at the effluent treatment plant at Federal University of Sergipe using a small batch reactor. The results showed that the species Chlorella vulgaris were able to assimilate phosphorus and to remove organic matter (Chemical Oxygen Demand, COD) from the effluent. The results showed that photobioreactors using microalgae for the treatment of effluents is a promising technique and motivate additional studies, mainly due to their capability of adding value to the biomass generated during the treatment.

Esterification of decanoic acid with methanol using Amberlyst 15: Reaction kinetics

ABSTRACTMethyl decanoate is used as a surrogate fuel. The surrogate fuels are structurally similar to actual biodiesel. We synthesized methyl decanoate in a small batch reactor by esterification reaction using decanoic acid and methanol on solid acid catalyst Amberlyst 15 used in dry state. The outcome of different reaction parameters including catalyst loading, temperature, molar ratio, stirrer speed, water concentration effect, and adsorption on catalyst pellets were studied for optimization of rate of conversion. The effect of external and internal diffusion limitations on catalyst granules was calculated theoretically from the reaction kinetics data. An analysis of the reaction kinetics revealed that the esterification reaction was rate controlled by adsorption of methanol on the solid acid catalyst and the reaction can be modeled as Eley–Rideal model. Activation energy of the esterification reaction was 39.4 KJ/mol. Reaction enthalpy and entropy were found to be 29.81 kJ/mol and 87.38 J/mol. K, respectively.

Effect of Different Clay Minerals on Heavy Oil Oxidation during Ignition Process

During the procedure of in situ combustion (ISC) for heavy oil, the rate of heat release at the low temperature oxidation (LTO) stage directly affects the delay time and the effect of ignition. This paper aimed at various clay minerals effects on heavy oil oxidation before ignition, at different reservoir temperatures and air/oil ratios, using a small batch reactor (SBR). Characterizations of the pressure, the reaction temperature, the post-test gases, the viscosity, and the asphalt content of heavy oil before and after oxidation were carried out. The results indicated that the catalysis of clay minerals was enhanced with the increase of temperature and air/oil ratio. At a rather lower temperature (90 °C), all three types of clay minerals did not obviously affect the temperature increment or rising rate at LTO while they had a little effect on viscosity, but had great influence on asphalt content, which increased greatly after the reaction. At a rather higher temperature (150 °C), clay minerals had great ...

Experimental Investigations of Physical and Chemical Properties for Microalgae HTL Bio-Crude Using a Large Batch Reactor

As a biofuel feedstock, microalgae has good scalability and potential to supply a significant proportion of world energy compared to most types of biofuel feedstock. Hydrothermal liquefaction (HTL) is well-suited to wet biomass (such as microalgae) as it greatly reduces the energy requirements associated with dewatering and drying. This article presents experimental analyses of chemical and physical properties of bio-crude oil produced via HTL using a high growth-rate microalga Scenedesmus sp. in a large batch reactor. The overarching goal was to investigate the suitability of microalgae HTL bio-crude produced in a large batch reactor for direct application in marine diesel engines. To this end we characterized the chemical and physical properties of the bio-crudes produced. HTL literature mostly reports work using very small batch reactors which are preferred by researchers, so there are few experimental and parametric measurements for bio-crude physical properties, such as viscosity and density. In the course of this study, a difference between traditionally calculated values and measured values was noted. In the parametric study, the bio-crude viscosity was significantly closer to regular diesel and biodiesel standards than transesterified (FAME) microalgae biodiesel. Under optimised conditions, HTL bio-crude’s high density (0.97–1.04 kg·L−1) and its high viscosity (70.77–73.89 mm2·s−1) had enough similarity to marine heavy fuels. although the measured higher heating value, HHV, was lower (29.8 MJ·kg−1). The reaction temperature was explored in the range 280–350 °C and bio-crude oil yield and HHV reached their maxima at the highest temperature. Slurry concentration was explored between 15% and 30% at this temperature and the best HHV, O:C, and N:C were found to occur at 25%. Two solvents (dichloromethane and n-hexane) were used to recover the bio-crude oil, affecting the yield and chemical composition of the bio-crude.