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We determined the effects of different hydrothermal liquefaction (HTL) process variables (temperature, holding time, algae loading, and water loading) on 13 different elements in biocrude and the aqueous phase co-product. Reaction conditions included both fast and isothermal HTL. The concentrations of P, Mg, Na, and Ca in the biocrude had their highest values at the mildest HTL conditions explored, and the concentrations decreased precipitously as even moderate HTL conditions were used. The concentrations of Zn, Cu, and Ni do not show much variation with HTL severity, whereas the concentration of Fe in the biocrude first increases and then decreases. P and Na were the most abundant elements in the biocrude from fast HTL, but Fe was the most abundant from isothermal HTL. These results show that the HTL conditions can influence the concentrations of different metals and inorganic species in algal biocrude from HTL.

Metal–organic frameworks have recently been proposed as promising proton conducting materials for application in fuel cell technologies. Here, molecular dynamics simulations are used to reveal the microscopic mechanisms associated with water-mediated proton transport in the MIL-53 materials as a function of temperature, water loading, and pore size. The structure of the hydrated proton is found to resemble that of a distorted Zundel complex when the framework closes into a narrow-pore configuration. A transition to Eigen-like structures is then observed at higher water loading when the pores open as a result of the breathing effect. Although the free-energy barriers to proton transfer at room temperature are lower than in bulk water, proton transport in MIL-53 is largely suppressed, which is attributed to the low water mobility inside the pores. Faster proton diffusion is found at higher temperature, in agreement with conductivity measurements.

The water loading capacity and water cycle stability (40 adsorption/desorption cycles) of four nitro- or amino-functionalized MIL-101Cr materials (1-4) is assessed for heat transformation applications. Amino- or nitro-functionalized (1, 3) and partially amino- or nitro-functionalized MIL-101Cr (2, 4) have been synthesized through time-controlled postsynthetic modification of MIL-101Cr. The partially ffinctionalized materials (2, 4) contain about 78 mol 96 amino- or nitro-functionalized terephthalate linker. Hydrophilic nitro or amino functionalities were introduced into MIL-101Cr in order to achieve water loading at lower p/p(0) values for possible use in thermally driven adsorption chillers or heat pumps. Among the four materials studied, fully aminated MIL-101Cr-NH2, 1, and partially aminated MIL-101Cr-pNH(2), 2, showed the best water loadings (about 1.0 gH(2)O/gMIL) as well as water stability over 40 adsorption-desorption cycles. After 40 cycles, the X-ray powder diffractogram and Brunauer-Emmett-Teller (BET) surface determination of amino-functionalized materials indicated structural integrity with Delta(BET) = -6.3% after 40 cycles, while the nitro-functionalized MIL-101Cr exhibited a decrease in their BET surface of Delta(BET) = -25% and -20% for 3 and 4, respectively.

Water adsorption on the (001) surface of pyrophyllite [Al(OH)(Si2O5)] was investigated using density functional theory (DFT) with dispersion corrections and force field calculations. The DFT calculations show that a water molecule can bind either to one or to two basal oxygen atoms of the surface, with adsorption energies varying from −0.10 to −0.19 eV depending on the binding configuration and binding site. Because the water–water interactions are stronger than the water–surface interactions, the energetically preferred structures with two or more molecules on the surface are clusters reminiscent of their gas-phase counterparts. The trend in water–surface binding energies with the number of water molecules obtained from force field calculations qualitatively agrees with that predicted by the dispersion-corrected DFT calculations. However, the force field calculations give a low-energy structural motif with a water molecule coordinated to a hydroxyl group associated with the octahedral layer of the pyroph...

In this study, cornstalk was pretreated by an acid-chlorite delignification procedure to enhance the conversion of cornstalk to bio-oil in hot-compressed water liquefaction. The effects of the pretreatment conditions on the compositional and structural changes of the cornstalk and bio-oil yield were investigated. It was found that acid-chlorite pretreatment changed the main components and physical structures of cornstalk and effectively enhanced the bio-oil yield. Shorter residence time favored production of the total bio-oil products, whereas longer time led to cracking of the products. A high water loading was found to be favorable for high yields of total bio-oil and water-soluble oil. GC-MS analysis showed that the water-soluble oil and heavy oil were the complicated products of C(5-10) and C(8-11) organic compounds.

Reverse micelles are discrete nanoscale particles composed of a water core surrounded by surfactant. The amount of water within the core of reverse micelles can be easily manipulated to directly affect the size of the reverse micelle particle. The water loading capacity of reverse micelles varies with temperature, and water can be shed if reverse micelles are exposed to low temperatures. The use of water shedding from the reverse micelle provides precise and comprehensive control over the amount of water available to solvate host molecules. Proteins encapsulated within reverse micelles can be studied to determine the effects of confinement and excluded volume. The data presented here provide an important bridge between commonly employed dilute in vitro studies and studies of the effects of a crowded environment, as found in vivo. Ubiquitin was encapsulated within bis(2-ethylhexyl) sodium sulfosuccinate AOT reverse micelles under various degrees of confinement and was compared with an analogously reconstituted sample of ubiquitin in the commonly used molecular crowding agent bovine serum albumin. The effects of encapsulation were monitored using chemical shift perturbation analysis of the amide (1)H and (15)N resonances. The results also reconcile alternative interpretations of protein cold denaturation within reverse micelles.

Single industrial adsorbent pellets of zeolites 5A and 13X were mounted with a polymer capable of withstanding high temperatures. Adsorbents were characterized by mercury-porosimetry and low-temper...

Breakthrough behavior is investigated for an activated carbon bed fed with constant concentrations of organic vapors and a stepped concentration of water vapor. The organics are present as single components and binary mixtures, with both hydrophobic and hydrophilic organics considered. Experiments are performed using a fully automated fixed-bed apparatus, which enables breakthrough curve studies for gas mixtures over a wide range of concentrations, from much less than 1 ppm up to saturation. The adsorbed-phase mass transfer coefficient of water is found to be a strong function of water loading. The system response is complex, with behaviors for hydrophilic and hydrophobic compounds being quite different. A model incorporating an accurate description of the highly nonideal adsorption equilibria is developed to simulate all of the fixed-bed experiments and gives good agreement in time, trend, extent, and shape of the breakthrough curves.