Distillation Temperature Research Articles

Performance investigation of poly(vinylidene fluoride-cohexafluoropropylene) membranes containing SiO2 nanoparticles in a newly designed single vacuum membrane distillation system.

The current study focuses on the development of a superhydrophobic poly(vinylidene fluoride-cohexafluoropropylene) nanocomposite membrane suitable for vacuum membrane distillation by incorporating SiO2 nanoparticles. At loading hydrophobic nano-SiO2 particle concentration (0.50-1.50 wt.%), the developed nanocomposite membranes are optimized in terms of vacuum membrane distillation performance. The influence of temperature, vacuum pressure, and feed water flow is studied for desalinating high-salinity brine. The results show that the developed vacuum distillation membrane is capable of 95% salt rejection during the treatment of a highly saline feed (65,000 ppm) at fixed flow rates of 120L/h saline feed and different operating conditions consisting of feed inlet temperatures ranging from 40°C to 70°C and distillate inlet temperatures of 7-15°C. The vacuum membrane distillation process achieves 0.38-1.66% water recovery with increasing concentration factor, meaning that recovery is increased, and shows a specific electrical energy consumption of 5.16-23.90 kWh/m3 for product water. Overall, the newly designed membrane demonstrates suitability for a vacuum membrane distillation system. PRACTITIONER POINTS: Desalinate high-salinity brine (TDS > 35,000 ppm) using a vacuum membrane distillation system. A hydrophobic PVDF-HFP/SiO2 nanocomposite membrane development for vacuum membrane distillation. A newly designed single vacuum membrane distillation system for RO brine treatment.

Specifications for applying high octane additives to the motor gasoline in hot climate

The article analyzes the use of high-octane additives to motor gasoline used in hot climates. We have studied anti-knock additives as additives to improve the octane number of gasoline. An additive based on alcohols, octane-Booster, was used as such additives. Laboratory studies were carried out on the physicochemical parameters of AI-80 and AI-92 gasoline with the addition of an anti-knock additive. The results of the studies show that when gasoline is used in hot climates, the addition of high-octane components based on alcohols increases the octane number, but at the same time the boiling point of the light fraction of gasoline decreases. With an increase in the percentage of additive, the boiling point of the light fractions reached 58°C. Taking into account all the experimental data obtained, we suggest adding a percentage of this additive of no more than 3%, which shows the optimal octane number and distillation temperature of 10% gasoline for hot climates. With a further increase in concentration to 5%, the octane number increases, but at the same time the distillation temperature of 10% gasoline sharply decreases, which can lead to increased friction losses. When the concentration increased above 5%, the octane number did not change. To ensure optimal engine operating conditions in hot climatic conditions, we suggest ensuring that the boiling point of gasoline at the beginning of distillation is not lower than 40°C ÷ 43°C, and the distillation temperature of 10% gasoline is not lower than 70°C.

Isobaric Vapor-Liquid Equilibrium of Methyl Salicylate + Ethyl Salicylate and Methyl Salicylate + α-Pinene Binary Systems at 20.0 and 50.0 kPa

Gandapura oil, also called wintergreen oil in international trade, is evaluated based on the purity of its methyl salicylate content. Gandapura oil has several impurities including mainly ethyl salicylate and α-pinene, which can lower its quality and price. Indonesian local farmer’s gandapura oil has a low methyl salicylate content of only 82.23%, and appears in a dark red colour instead of clear. The low grade product may have been caused by thermal degradation of compounds within gandapura oil by constant heating during atmospheric distillation at temperature above its thermal threshold. The determination of their vapor-liquid equilibrium data can provide basic data for the separation and purification of methyl salicylate towards its two main impurities in gandapura oil. The vacuum pressure condition was selected to lower the distillation temperature, aiming to reduce the chance of thermal decomposition. The vapor-liquid equilibrium under isobaric conditions in the binary systems of methyl salicylate + ethyl salicylate and methyl salicylate + α-Pinene at 20.0 and 50.0 kPa were measured experimentally using modified Glass Othmer-Still. Gas Chromatography (GC) was utilized to analyze the composition of both the liquid and vapor phases in the samples. The thermodynamic consistency of experimental data was confirmed through the L-W Wisniak method. The experimental results were successfully correlated with Wilson, NRTL, and UNIQUAC models. The average absolute deviations of temperature (AAD T) and vapor phase composition (AAD y) between experimental data and models are less than 0.8058 and 0.0196, respectively for all systems. In terms of quality, all samples collected post-experiment maintained a clear color, suggesting that vacuum pressure distillation effectively prevents the thermal decomposition of compounds in gandapura oil.

Experimental investigation and calculation for Te-X (X=Cu, Pb and Fe) systems in vacuum distillation based on Gibbs-Duhem equation

Experiments on the relationship between temperature and vapor phase composition (T-y curve) of the Cu-Te and Pb-Te binary systems at 5 Pa were carried out, with distillation temperatures in the range of 900–1370 K and 724–920 K, respectively. The experimental results indicate that copper and lead can be satisfactorily removed from crude tellurium. The recovery rate of tellurium is relatively low due to the formation of a high melting point compound in the liquid phase. The activities of Cu and Pb of the Cu-Te and Pb-Te systems were obtained by function fitting and G-D equation, which are used to predict vapor phase composition. The results show good agreement with the experimental data. The activities and T-y curve of the Fe-Te binary system were calculated using the same method and believed to be reliable. A possible high-purity tellurium production cycle combined with vacuum distillation was also discussed.

Storage stability of biocrude oil fractional distillates derived from the hydrothermal liquefaction of food waste

Biocrude oil produced via hydrothermal liquefaction (HTL) is a promising precursor for transportation fuels and biochemicals. Present studies have highlighted the inherent instability of the biocrude oil, which poses significant challenges for its subsequent storage, upgrading and transportation. On the other hand, biocrude oil distillates showed the potential to serve as a transportation fuel blendstock. To this end, this study aimed to investigate the influence of the distillation temperature (199–238 °C and 238–274 °C), storage atmosphere (air and nitrogen), temperature (25 °C and 55 °C), and time (0–16 weeks) on the physical, chemical, and boiling point distribution properties of the distillates. Results demonstrated that changes in the stored distillates due to different distillation temperature were drastically higher than that between different storage atmospheres and temperatures. Comparing with the raw distillate, the distribution of compounds with a molecular weight < 300 Da in low-temperature (199–238 °C) distillates (LD) and medium-temperature (238–274 °C) distillates (MD) was improved with the increasing storage time. In addition, storage led to a decrease in O:C ratio (21.6 % and 86.5 %), and an increase in the HHV (3.6 % and 12.3 %) in the LD and MD, respectively. Furthermore, only slight deviations were observed in the density (5.2 % and 7.4 %) and viscosity (5.2 % and 0.8 %) for LD and MD, respectively. In particular, the MD group exhibited comparable characteristics to transportation fuels with decreased acidity (1.8–2.8 mg KOH/g) and increased HHV (46.2–46.8 MJ/kg) after long-term storage. At last, the mechanism of superior distillates stability was discussed. This study indicated that distillation not only presents a potential approach for producing transportation fuel blendstock but also improves the stability of HTL biocrude oil.

Modeling and experimental evaluation of membrane distillation aimed at urine treatment for direct potable reuse in space stations

Improving wastewater reuse systems represents a game changer for the economy of space exploration activities. The goal of this research is to evaluate direct contact membrane distillation for the treatment of urine aimed at direct potable reuse in space stations. A transient, 2-D model able to predict the membrane distillation system behavior under different operating conditions is developed. The model is validated by experimental tests conducted with a synthetic urine-like feed solution, considering both productivity and final water quality. The water flux and quality analyses imply high rejection of soluble salts and organics. However, direct water reuse may be compromised by the ammonia passage. A sensitivity analysis is thus performed to investigate the effects of feed pH, temperature, and cross-flow velocity on water flux and ammonia passage. The system shows the capability of treating 8 L of urine up to 90–95 % recovery rate, during 10 h of daily operation at 40 °C feed and 20 °C distillate inlet temperatures. This amount is sufficient to satisfy four crew members while meeting high system compactness. Concurrently, the ammonia passage may be limited by lowering the feed pH, thus easing the post-treatment steps necessary for safe direct reuse.

Density, Viscosity, and Distillation Temperatures of Binary Blends of Diesel Fuel Mixed with Oxygenated Components at Different Temperatures

This paper reports density, kinematic viscosity, and distillation curves for blends of diesel fuel with n-butanol, diesel fuel with n-pentanol, and diesel fuel with diethylene glycol dimethyl ether. It is known that these properties affect not only fuel transportation and distribution processes but also the phenomena that occur in an internal combustion engine; therefore, these aspects are intriguing to study. Oxygenated compounds such as n-butanol, n-pentanol, and diethylene glycol dimethyl ether can be used as additives for diesel fuel. Their use can contribute to a significant improvement in the fuel’s ignitability due to their high oxygen contents. Measurements of the experimental properties of various blend compositions were carried out at temperatures ranging between 288.15 K and 323.15 K. Based on density and viscosity data, different mathematical models were verified for the purpose of establishing better quality standards for the production of fuel. Good accuracies were obtained in the cases of density, viscosity, and interaction parameters, with the largest average absolute deviation (AAD%) being 0.4351. Moreover, as the determination of density is uncomplicated, rapid, and requires small sample volumes, correlations with the distillation temperatures used for the fuel blends were investigated to estimate the samples’ cetane indices. These determinations will be useful in the automobile industry when designing transport equipment or pipelines in situations when oxygenated compounds may constitute a fuel component in diesel blends.

A novel process for directional impurity removal and preparation of front-end high-purity antimony from crude antimony

Aiming to separate the trace impurities in crude antimony and to provide a foundation for the preparation of front-end high-purity antimony, two processes of low temperature-high temperature vacuum distillation (LHVD) and high temperature-low temperature vacuum distillation (HLVD) were performed for the deep purification of crude antimony. The removal rates of Bi, Zn, and Cd from products using LHVD were 77.20 %, 34.78 %, and 27.82 %, respectively, under the optimal conditions of 1–10 Pa, a holding time of 90 min, a low-temperature stage of 873 K, and a high-temperature stage of 923 K. The content of impurities in antimony was 39 ppm, and samples with antimony content 9999.61 ppm were obtained. The removal rates of Bi, Zn, and Cd from products using HLVD were 43.89 %, 83.51 %, and 56.21 %, respectively, under the optimal conditions of 1–10 Pa, a holding time of 90 min, a high-temperature stage of 923 K, and a low-temperature stage of 873 K. The impurity content in antimony was 52.94 ppm, and samples with antimony content 9999.47 ppm were obtained. The trace impurities in crude antimony can be effectively removed via a two-stage vacuum distillation. This study provides a reference for the deep purification and front-end preparation of high-purity antimony.

Boiling point modeling for petroleum speciation data

An empirical model is presented for generating the boiling curve of a petroleum sample based on parameters that are experimentally available using typical speciation techniques. The approach estimates the boiling point distribution of the detected components and allows a comparison with the simulated distillation profile of the sample. The model is shown to predict the boiling behavior of the speciation-derived average components in crude oil distillation fractions, which match the measured average distillation temperature of the fractions. The model is then applied to generate boiling distributions, based on mass spectrometric and gas chromatographic speciation data, which match the measured simulated-distillation curves with less than 20 °C difference. The model is also applied to the isolated fraction of saturated compounds, where the modeled boiling profile matches well with the measured distillation profile of the entire sample. This confirms that the model, although built using Fourier transform ion cyclotron resonance mass spectrometry data of aromatic compounds, extends to data obtained using comprehensive 2-dimensional gas chromatography, and also describes the boiling behavior of saturated compounds speciated by field desorption time of flight mass spectrometry. Consequently, the modeled boiling distribution enables an assessment of how well a speciation measurement describes the sample, and provides an estimation of lower and higher-boiling portions that have been omitted in the data set.

Reverse electrodialysis characteristic of the LiBr-ethanol-water ternary solution

Reverse electrodialysis heat engine (REDHE) has a large potential to convert low-grade heat into electrical energy. Working fluids with low distillation temperature and excellent ion migration properties are essential for the performance improvement of the REDHE. Here, we propose an ethanol-assisted LiBr aqueous to simultaneously decrease the distillation temperature and improve the performance of the REDHE. However, the unclear reverse electrodialysis (RED) characteristics of the ternary working fluid greatly block the application of the REDHE system. To this end, the ternary working fluid of LiBr-ethanol-water is respectively applied to a single-stage RED and multi-stage RED (MS-RED) stacks experiments for the first time, which clearly unveil the RED characteristics of the LiBr-ethanol-water ternary solutions under various working conditions. Both the solution compositions (solvent ratio and concentration) and the working parameters (flow velocity and feed temperature) are systematic studied. The concentration has the most excellent effect on the output performance of the RED stack, followed by temperature and flow rate. The single-stage RED could achieve a power density of 1.17 W m−2. Furthermore, the cumulative energy conversion efficiency of the MS-REDs is increased by 6.73 times from 1.48% to 11.45% as the stage number is stacked from 1 to 22 in series.

A new process for accumulation and purification of lead sulfide from complex lead ore

The conventional method for producing lead sulfide (PbS) suffers from issues such as low efficiency, heavy pollution, and high raw material requirements. This study introduces a novel approach aggregation followed by purification, for the preparation of PbS from complex lead ore. The feasibility of separating and enriching PbS under vacuum conditions is analyzed theoretically. The initial stage of vacuum accumulation focuses on investigating the impact of distillation temperature and distillation time on the sublimation and direct yield of PbS in minerals with a vacuum pressure of 5Pa. The findings indicate that optimal PbS accumulation parameters are achieved at 1103 K for 60 min, resulting in a direct yield of 99.10%. The subsequent step involves distillation purification, wherein PbS is subjected to distillation at 923 K for 120 min. This process enhances the purity of PbS to over 99.50%, with a direct yield of 96.19%. The method of accumulation followed by purification presents a new and promising approach for the efficient acquisition of PbS, offering a viable means for the comprehensive utilization of complex lead ore. This method can alleviate the current challenge of relying solely on high-grade lead concentrate for lead supply.

Preparation of high-purity copper through vacuum distillation

Copper is capable of maintaining strong competitiveness in the metal materials market for its prominent ductility, thermal conductivity, and electrical conductivity. As more rigorous purity requirements of industrial sputtering targets and aerospace have been raised, the clean and efficient production of high-purity copper turns out to be an urgent problem over the past few years. In this paper, the possibility of removing impurities from copper melt was investigated by integrating theoretical calculations and experiments, and the separation coefficient and vapor-liquid equilibrium phase diagram of copper and impurity elements were determined and plotted using the molecular interaction volume model (MIVM). Moreover, the effects of the distillation temperature, the holding time, and the system pressure on the experimental results were discussed. As indicated by the results, with the rise of the temperature and with the extension of the holding time, the purity of copper was first increased and then decreased, and the purity of residual copper reached 99.9993% at 1473 K temperature, 1.5 h holding time, and 5 Pa pressure, and the method effectively separated impurities from copper raw materials. Besides, no waste water or waste gas emission was generated in the experiment.

Influence of the Evaporation Temperature and Degree of Distillation on the Effective Separation Factor

Influence of the Evaporation Temperature and Degree of Distillation on the Effective Separation Factor

Using the poly-lactic acid as a fuel additive to enhance the physicochemical properties of aircraft jet fuel grade A1

The combustion quality and energy content of Jet fuel are important to fuel characteristics. There are some essential performance characteristics include density, flash point, freezing point, kinematic viscosity at -20o C, smoke point, and distillation temperatures should be detected and controlled. In this study, an experimental investigation was performed in order to determine the effects of polylactic acid, tetrahydrofuran, and Jet A1 fuel blends on the physical and chemical properties of blends. For this purpose, the fuel blends studied were analyzed using Miniscan IR which is a high speed for the comprehensive and automatic measurement of Jet fuels. From our results, it was found that the maximum flash point enhancement was obtained by S3 (95%Jet A1/5%THF/250ppmPLA) (42.3oC) while it was (38oC) for the blank Jet fuel A1. On the other hand, the decreasing of freezing point was achieved by S6 (95%Jet A1/5%THF/2500ppmPLA) (-65.4oC), while it was (-62.6oC) for the blank Jet fuel. The maximum net heat of combustion value was obtained by S2 (95%Jet A1/5%THF) (56.44 MJ/kg), while it was (55.62 MJ/kg) for the blank sample. Also, the density slightly increased for all Jet blended samples. The net heat of combustion values were enhancement, compared with blank Jet fuel A1.

Analysis of the Calorific Value and Specific Gravity of Breadfruit Peel Bioalcohol (Artocarpus Altilis) as an Alternative Fuel at Various Distillation Temperatures

The objective of this study was to investigate how distillation temperature affected the specific gravity (SG) and calorific value of bioalcohol derived from breadfruit peels (Artocarpus altilis) as an alternative fuel. The process of producing bioethanol from breadfruit peels begins with pretreatment of the peels, followed by hydrolysis with hydrochloric acid, fermentation, and finally distillation. The hydrolysis process used 20% hydrochloric acid in a volume of 25 ml, and the fermentation took 6 days with a mass of 30 gr of yeast Saccharomyces cerevisiae. The distillation process lasted two hours, with temperatures varying between 70, 80, and 90°C. This study yielded the highest alcohol content of 72.80% at 70°C and the highest volume of bioalcohol of 35.67 ml at 90°C. Meanwhile, the best Specific Gravity (SG) at 70°C was 0.8393. Furthermore, the calorific value test results revealed that the calorific value increased with increasing alcohol content. The highest calorific value obtained was 23003.406 J/gr, which was close to the ethanol calorific value of 29700 J/gr, while the lowest calorific value obtained was 22339.008 J/gr at a distillation temperature of 90°C

Cutting Weights of Deep Learning Models for Heart Sound Classification: Introducing a Knowledge Distillation Approach.

Cardiovascular diseases (CVDs) are the number one cause of death worldwide. In recent years, intelligent auxiliary diagnosis of CVDs based on computer audition has become a popular research field, and intelligent diagnosis technology is increasingly mature. Neural networks used to monitor CVDs are becoming more complex, requiring more computing power and memory, and are difficult to deploy in wearable devices. This paper proposes a lightweight model for classifying heart sounds based on knowledge distillation, which can be deployed in wearable devices to monitor the heart sounds of wearers. The network model is designed based on Convolutional Neural Networks (CNNs). Model performance is evaluated by extracting Mel Frequency Cepstral Coefficients (MFCCs) features from the PhysioNet/CinC Challenge 2016 dataset. The experimental results show that knowledge distillation can improve a lightweight network's accuracy, and our model performs well on the test set. Especially, when the knowledge distillation temperature is 7 and the weight α is 0.1, the accuracy is 88.5 %, the recall is 83.8 %, and the specificity is 93.6 %.Clinical relevance- A lightweight model of heart sound classification based on knowledge distillation can be deployed on various hardware devices for timely monitoring and feedback of the physical condition of patients with CVDs for timely provision of medical advice. When the model is deployed on the medical instruments of the hospital, the condition of severe and hospitalised patients can be timely fed back and clinical treatment advice can be provided to the clinicians.

A framework for enhancing industrial soft sensor learning models

Refinery industrial processes are very complex with nonlinear dynamics resulting from varying feedstock characteristics and also from changes in product prioritization. Along these processes, there are key properties of intermediate compounds that must be monitored and controlled since they directly affect the quality of the end products commercialized by these manufacturers. However, most of these properties can only be measured through time-consuming and expensive laboratory analysis, which is impossible to obtain in high frequencies, as required to properly monitor them. In this sense, developing soft sensors is the most common way to obtain high-frequency estimations for these measurements, helping advanced control systems to establish the correct setpoints for temperatures, pressures, and other sensors along the refining process, controlling the quality of end products. Since the amount of labeled data is scarce, most academic research has focused on employing semi- supervised learning strategies to develop machine learning (ML) models as soft sensors. Our research, on the other hand, goes in another direction. We aim to elaborate a framework that leverages the knowledge of domain experts and employs data augmentation techniques to build an enhanced fully labeled dataset that could be fed to any supervised ML algorithm to generate a quality soft sensor. We applied our framework together with Automated ML to train a model capable of predicting a specific key property associated with the production of Naphtha compounds in a refinery: the ASTM 95% distillation temperature of the Heavy Naphtha. Although our framework is model agnostic, we opted by using Automated ML for the optimization strategy, since it applies a diverse set of models to the dataset, reducing the bias of utilizing a single optimization algorithm. We evaluated the proposed framework on a case study carried out in an industrial refinery in Brazil, where the previous model in production for estimating the ASTM 95% distillation temperature of the Heavy Naphtha was based entirely on the physicochemical knowledge of the process. By adopting our framework with Automated ML, we were capable of improving the R2 score by 120%. The resulting ML model is currently operating in real-time inside the refinery, leading to significant economic gains.

A luminescent thermosensitive coating for a non-invasive and in-situ study of thermal polarization in hollow fiber membranes

A new non-invasive method to evaluate the thermal polarization is herein proposed for hollow fiber (HFs) membranes during the Direct Contact Membrane Distillation (DCMD) process. The goal was reached by using a temperature-sensitive phosphorescent molecular probe such as Tris(phenanthroline) ruthenium(II) chloride (Ru(phen)3) and an infrared camera (IR) camera, to map, in-situ, the thermal profile directly at the membrane surface which is in contact with the hot feed water solution. The molecular probe was immobilized, by means of a perfluoropolyether (PFPE)-based coating, on the surface of a polypropylene HF in order to obtain a thermosensitive polymerized coating. The produced HFs were fully characterized in order to demonstrate the successful embodiment of the molecular probe on the surface of the membrane and their suitability, in terms of pore size, hydrophobicity and stability, for DCMD application. The luminescent activity of the immobilized Ru(phen)3 complex was measured by a bifurcated optical fiber, one branch was used to excite the molecular probe and the other branch was able to constantly monitor the molecular emission which was dependent on the temperature along the HF surface. The HFs were tested in DCMD at different feed temperatures (40 °C, 50 °C, 60 °C) and constant conditions of streams flow rate and distillate temperature (Qf = 90 L/h; Qp = 24 L/h; Tp = 13 °C). The obtained results clearly demonstrated the possibility of studying the thermal polarization phenomenon occurring during DCMD, with the temperature profile developed on the HF surface monitored, for the first time, at molecular level using a non-invasive technique. This approach can shed the light on better understanding this phenomenon and the possible strategies for its mitigation and counteraction.

A multi-stage volatilization and condensation process for green and efficient recovery of valuable metals from High-Sb crude Sn

Circulation of Sb in an Sn refining system strongly affects the production process. In this study, an innovative multi-stage vacuum separation process was developed and successfully applied on an industrial scale. Our results indicate that Sn–Sb alloys can be completely separated by vacuum evaporation. In this study, we used single-factor experiments to investigate the effects of distillation temperature and time on several factors, such as the Sn content in the residue, Sb content in the volatile matter, separation rate, and direct recovery rate of Sb from high-Sb crude Sn. The purity of the obtained Sn and Sb products was above 99%, and the recovery rate of the metal was above 99% under the optimal distillation conditions of 1673 K and 150 min. In addition, we suggest that Sn volatilization occurs due to the presence of SbSn intermetallic compounds. A two-stage vacuum-separation process for high-Sb crude Sn was developed for industrial production. Continuous production data showed that the direct yields of Sn and Sb were 72.99% and 71.15%, respectively. The total power consumption of this process was as low as 1086 kWh/t, which is better than the corresponding parameters of other treatment processes.

Effect of Blending Aromatic and Oxygenates Additives with Fuels to Enhance Fuel Properties

This work aims to show the influence of several oxygenates and aromatic additives in different types of unleaded fuels in the Kurdistan region of Iraq on upgrading the physicochemical properties of blends. Consuming super-grade gasoline as a fuel for automotive cars can produce large amounts of environmental emissions, a severe global problem, especially in the Kurdistan region in recent years. The physicochemical properties of mixtures, such as the research octane number (RON), Motor Octane number (MON), density, and distillation curves, will be tested by using ERASPEC spectroscopy as a fuel properties analyzer. As a result, the blending process has improved the gasoline grade to super grade by enhancing the physicochemical properties of blends. The additives used in this work as oxygenators are; Ethanol and Methyl Tertiary Butyl Ether (MTBE) added to two base fuels, light Naphtha, and unleaded Gasoline, in various ratios of (5%, 10%, 15% and 20%). An aromatic component (Aniline) is also mixed with light Naphtha and base gasoline in low concentrations (1%, 3%, and 5%). The results of blending Ethanol, MTBE, and Aniline with fuels demonstrate that the Research Octane Number RON and Motor Octane Number MON of fuels increase with the addition of different ratios of all-octane boosters. The best-recorded result of both types of octane numbers (13 points increased from the bases) is recorded by blending 3% of Aniline with the fuels. However, Ethanol can provide a more significant increase in (RON) and (MON) than MTBE for the same blending ratio. The Density of the mixtures also increases because both additives have a higher density than the fuel due to the presence of different hydrocarbon compounds. The mixture's distillation curves are distorted, especially when the low to the middle percent of blenders are added to fuels. However, higher percentages of additives show lower distillation temperatures.