A luminescent solar concentrator (LSC) is a potential low‐cost enhancement of the standard large‐area silicon photovoltaic panels for the generation of electricity from sunlight. In this work, guest–host systems are investigated using anisotropic fluorescent dyes and liquid crystal mesogens to control the direction of emitted light in the LSC. It is determined that up to 30% more light is emitted from the edge of an LSC waveguide with planar dye alignment parallel to the alignment direction than from any edge of an LSC with no alignment (isotropic). The aligned samples continue to show dichroic performance after additions of both edge mirrors and rear scattering layer.

Summary Chemical enhanced oil recovery (EOR) leads to substantial incremental costs over waterflooding of oil reservoirs. Reservoirs containing oil with a high total acid number (TAN) could be produced by the injection of alkali. Alkali might lead to the generation of soaps and emulsify the oil. However, the generated emulsions are not always stable. Phase experiments are used to determine the initial amount of emulsions generated and their stability if measured over time. On the basis of the phase experiments, the minimum concentration of alkali can be determined and the concentration of alkali above which no significant increase in the formation of initial emulsions is observed. Micromodel experiments are performed to investigate the effects on the pore scale. For the injection of alkali into high-TAN oils, the mobilization of residual oil after waterflooding is seen. The oil mobilization results from the breaking up of oil ganglia or the movement of elongated ganglia through the porous medium. As the oil is depleting in surface-active components, residual oil saturation is left behind either as isolated ganglia or in the down gradient side of grains. Simultaneous injection of alkali and polymers leads to a higher incremental oil production in the micromodels owing to larger pressure drops over the oil ganglia and more-effective mobilization accordingly. Coreflood tests confirm the micromodel experiments, and additional data are derived from these tests. Alkali/cosolvent/polymer (ACP) injection leads to the highest incremental oil recovery of the chemical agents, which is difficult to differentiate in micromodel experiments. The polymer adsorption is substantially reduced if alkali is injected with polymers compared with polymer injection only. The reason is the effect of the pH on the polymers. As in the micromodels, the incremental oil recovery is also higher for alkali/polymer (AP) injection than with alkali injection only. To evaluate the incremental operating costs of the chemical agents, equivalent utility factors (EqUFs) are calculated. The EqUF takes the costs of the various chemicals into account. The lowest EqUF and, hence, the lowest chemical incremental operating expenditures are incurred by the injection of Na2CO3; however, the highest incremental recovery factor is seen with ACP injection. It should be noted that the incremental oil recovery owing to macroscopic-sweep-efficiency improvement by the polymer needs to be accounted for to assess the efficiency of the chemical agents.

Glycerol is an attractive renewable building block for the synthesis of polyglycerols, which find application in the cosmetic and pharmaceutical industries. The selective etherification of glycerol to higher oligomers was studied in the presence of CaO colloids and the data are compared with those obtained from NaOH and CaO. The materials were prepared by dispersing CaO, CaCO3, or Ca(OH)2 onto a carbon nanofiber (CNF) support. Colloidal nanoparticles were subsequently dispensed from the CNF into the reaction mixture to give CaO colloids that have a higher activity than equimolar amounts of bulk CaO and NaOH. Optimization of the reaction conditions allowed us to obtain a product with Gardner color number <2, containing no acrolein and minimal cyclic byproducts. The differences in the CaO colloids originating from CNF and bulk CaO were probed using light scattering and conductivity measurements. The results confirmed that the higher activity of the colloids originating from CaO/CNF was due to their more rapid formation and smaller size compared with colloids from bulk CaO. We thus have developed a practical method for the synthesis of polyglycerols containing low amounts of Ca.

With the ever-growing demand for more environmentally friendly oilfield chemicals, classic oilfield chemistries are no longer acceptable and new chemical systems are required. Future oil production will still require efficient dehydration and desalting of crude oil. In addition, the protection of the affected environment will be of increased significance.The industrial availability of ethylene oxide in the 1940s firstly allowed the design of nonionic surfactants for emulsion breaking. With the development of ethylene oxide / propylene oxide block copolymers, the first highly efficient crude oil demulsifers were available. The addition of ethylene oxide / propylene oxide to alkylphenol formaldehyde resins and to oligoamines yielded emulsion breakers that performed sufficiently at low concentrations.To achieve the future requirements of environmentally acceptable oilfield chemicals, emulsion breakers with low toxicity and high biodegradability are needed. Due to the fact that nonionic alkoxylate based polymeric surfactants have in general a low toxicity, biodegradation was identified as the major bottle neck. Above described polyether type chemistries usually show low biodegradation due to their high molecular weights, especially in marine biodegradation tests (OECD 306) which are often required. Alkylphenol resins have an improved biodegradation profile in comparison to the polyether types, but some serious toxicity issues.Polyesters are well known as highly biodegradable polymers with low toxicity and a lot of effort was made to design polyester based demulsifers. This paper describes the development of biodegradable alkoxylated polyester dendrimers for breaking oil/water emulsions.

Enhanced oil recovery methods are appealing to increase oil recovery from reservoirs due to market pressures in times of lower oil price. Chemical enhanced oil recovery (cEOR) methods such as ASP involve the use of alkali, surfactant, and polymer, to create an ultralow interfacial tension (IFT) between microemulsion and oil phases. These chemicals have the potential to interact with asphaltenes in crude oil and may cause either a decrease or an increase in asphaltene deposition. This paper presents an investigation into the effects of ASP chemicals on asphaltene precipitation. Crude oil, from a cEOR-nominated Kuwaiti reservoir, was analyzed with an ASP formulation that was determined through microemulsion phase behavior experiments. Crude oil, chemical components, and incompatible solvent were added together, and light transmission was measured over a 15-minute period to determine asphaltene precipitation over time. A blank graph of the crude in incompatible solvent showed a light transmission increase of 36.2% over the test duration indicating asphaltene precipitation. If asphaltenes remain suspended in oil, light transmission remains low and stable from the beginning to the end of the test. Addition of asphaltene inhibitor (AI) to the crude oil prevented asphaltene flocculation which was evidenced by a maximum light transmission of 3.0%, an efficiency of 91.7% dispersability relative to the blank sample. With addition of the ASP formulation, light transmission increased which indicates interaction between (1) chemical species of the ASP formulation with asphaltenes or (2) the alkali in the chemical package altering the pH and causing more asphaltene precipitation from suspension in the crude. Maximum light transmission of oil dosed with the chemical additives is 41.3% which is a decrease in asphaltene inhibition efficiency of 14.1% relative to the blank. With the addition of AI to the crude containing the chemical additives, the maximum light transmission is 6.5% indicating an efficiency of 82% asphaltene dispersability. Results indicate a clear relationship between addition of ASP chemicals and asphaltene precipitation. Conditions will differ for other crude oils and cEOR formulations, but asphaltene scaling issues should be considered for cEOR projects.