High accuracy p-rho-t measurements up to 200 MPa between 200 K and 500 K using a compact single sinker magnetic suspension densimeter for pure and natural gas like mixtures

Highly accurate density data is required for engineering calculations to make property estimations in natural gas custody transfer through pipelines. It is also essential to have accurate pressure-volume-temperature (PVT) data for developing equations of state (EOS). A highly accurate, high pressure and temperature, compact single sinker magnetic suspension densimeter has been used for density measurements. First, the densimeter is calibrated against pure component densities for which very reliable data are available. After validating its performance, the densities of four light natural gas mixtures that do not contain components heavier than hexane and two heavy gas mixtures containing hexane and heavier components having fractions more than 0.2 mole percent were measured. The light mixtures were measured in the temperature range of 250 to 450 K and in the pressure range of 10 to 150 MPa (1450 to 21,750 psi); the heavy mixtures were measured in the range of 270 to 340 K and in the pressure range of 3 to 35 MPa (500 to 5,000 psi). Out of those, the data for only four light natural gas mixtures have been presented in the dissertation due to confidentiality agreements that are still in force. A force transmission error and uncertainty analysis was carried out. The total uncertainty was calculated to be 0.11%. Data calculated in this work is compared with the current industry standard EOS for natural gas systems (AGA8-DC92 EOS) and GERG EOS, which is the most recently developed EOS for natural gas systems. The data measured as a part of this research should be used as reference quality data, either to modify the parameters of AGA8-DC92 EOS and GERG EOS or to develop a more reliable equation of state with wider ranges of pressure and temperature

Review and Perspectives for Effective Solutions to Grand Challenges of Energy and Fuels Technologies via Novel Deep Eutectic Solvents

Sustainable technologies applied to energy-related applications should develop a pivotal role over the next decades. Therefore, the development of new materials for old processes has merged as a central research line lately. Deep eutectic solvents (DESs) have been recently considered alternative and economic task-specific solvents for many chemical and environmental processes. The low-cost production of DESs production from natural sources and their tunable properties, such as neat null toxicity and biodegradability, make these solvents suitable candidates for various processes within the green chemistry framework. Considering the millions of possible DES combinations yet to be explored, a detailed review of DES research’s current status that can elaborate on the structure–property relationship is an essential task to identify the missing links and strong points on DES research. Thus, this review work focuses on the recent research efforts on the utilization of DES on chemical processes, with the purpose of elucidation on gas capture/separation, fuel desulfurization, biodiesel production, and water treatment processes and provides a deeper understanding on outstanding scientific questions and identifies promising new research directions that involve DESs.Ministerio de Ciencia, Innovación y Universidades (Spain, Project No. RTI2018-101987-B-I00) and Western Michigan University Research Fund (No. 11-1211410-4850)

Nanoscopic characterization of type II porous liquid and its use for CO2 absorption from molecular simulation

The properties of cage(33:133) macrocycle in perchloropropene (PCP) as model for type II porous liquids were studied using molecular simulation tools. Likewise, the behaviour of CO2 in these porous liquid phases were studied to analyse the nanoscopic mechanism for carbon capture purposes. Quantum chemistry calculations using Density Functional Theory were carried out to characterize the intermolecular forces between cage, solvent and CO2 molecules. Molecular dynamics simulations of liquid phases at different cage concentration provides information on the structuring, aggregation, solvation and dynamic properties of these porous liquids. The reported results led to a full characterization of the features controlling type II porous liquids properties as well as the behaviour of carbon dioxide in them, thus providing the required information for the proper design of porous liquids and their use for carbon capturing operations. The nanoscopic structure of the studied fluids showed that it is possible to solubilize suitable amounts of the cages in the solvents to develop a network of pores in the liquid to capture CO2 in an efficient way.Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00) and by Junta de Castilla y León (Spain, project BU094G18). We acknowledge SCAYLE (Supercomputación Castilla y León, Spain) for providing supercomputing facilities

Molecular dynamics study on water confinement in deep eutectic solvents

The nanoscopic properties of highly diluted water solutions in choline chloride + lactic acid deep eutectic solvent was studied using molecular dynamics simulations as a function of concentration and temperature with the objective of characterize the confinement of water in deep eutectic solvents as a non-regular confinement mechanism. The simulations allowed the analysis of changes in the properties of the deep eutectic solvent in response to the water presence as well as the behaviour of confined water in solvent cavities. The analysis of structural, energetic and dynamic factors provides for the first time the characterization of water confined in these environmentally friendly solvents. The results showed how water can be confined in deep eutectic solvents liquid cages maintaining water individuality with minor changes in the solvent properties, which can be used for tuning water properties for the development of technological applications.Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00). We acknowledge SCAYLE (Supercomputación Castilla y León, Spain) for providing supercomputing facilities

Natural Gas Hydrates

Sir Humphry Davy witnessed the first chlorine hydrate crystallizing in 1811. Couple of century later his discovery, natural gas hydrates has begun to play an important role in energy business. From being a mere chemical curiosity, they have proven to be a nuisance for the natural gas industry. The problem of hydrate induced blockage in âwet gasâ flow systems has been widely reported and became a major flow assurance issue in the energy sector[1]. The importance of pipeline blockage increased in the 70âs when plugging of even the largest diameter pipelines from offshore, arctic fields or the wells from high-pressure underground storage facilities were reported. Studies over the past two decades showed that large gas hydrate plugs form most often after shut-in pipelines or wells begin to flow[2]. When a pipeline is shut-in, the fluid separates into the gas water and hydrocarbons as the temperature decreases[3]

Intermolecular forces in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + ethanol mixtures

The characteristics of intermolecular forces in 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide + ethanol mixtures were studied in the full composition range using a combined experimental and theoretical approach. Molecular clusters were used to model the short-range interactions between the ionic liquid and the primary alcohol, studied using density functional theory calculations, inferring preferred interaction sites, strength of interactions and topological characteristics of intermolecular forces. Dynamic viscosity and refraction index were measured as a function of mixture composition and temperature and analysed in terms of evolution of intermolecular forces. Raman IR studies were carried out and the analysis of selected spectral regions allowed to characterize hydrogen bonding evolution for all the possible interacting sites.Junta de Castilla y León (Spain, project BU324U14