Plastic an polymers. Srebrina Yaneva@iStockphoto

The tendency of dissimilar particulate solids to segregate into one another restricts their homogeneous mixture. It is shown theoretically and experimentally that loading of a downward segregating key component in a batch mixer of particulate solids as several layers distributed within another component allows reducing considerably the required mixing time and improving the mixture quality.

Easy to implement, fast, and precise erosion and breakage models are essential for engineers to predict these effects in conveying systems. A major challenge is to evaluate the collision characteristics in terms of the flow conditions. These functions are produced by correlating them to governing parameters under different operating conditions to aid the prediction of attrition or erosion.

The quality of granular mixing has great importance in many applications. Herein, simulations of granular mixing and segregation of binary-sized mixtures using a discrete element method were performed for horizontal rotating drum mixers. The formation of axially segregated bands relative to operating conditions, drum dimensions, and the initial distributions of particles was analyzed.

Drill cuttings are categorized as hazardous waste and, therefore, need to be stored intermediately in silos instead of being dumped into the sea. However, conveying drill cuttings is a challenging task. In this basic pilot-scale experimental and simulation study, sand is used as model material and it is shown that pneumatic conveying can be used to transport dry drill cuttings.

A device is used to capture pictures of laser light projected onto the inner surfaces of pipes. Such images are processed and analyzed to describe and quantify scale depositions in cross sections of pneumatic conveying pipelines. Measurements obtained by the device can be used as reliable references to calibrate empirical scale thickness models based on data from online monitoring techniques.

Drill cutting storage in offshore drilling rigs is a challenging task. Oily cuttings can easily cause discharge issues, so a proper scientific study is required. The impact of a base oil and a premix to the hopper angle and opening width of a silo is studied. The viscosity of the fluid plays a major role, hence, the flow properties have to be defined experimentally for different drilling fluids.

CaCO₃ can be produced through biomineralization, e.g., by Coccolithophorida, which can generate small CaCO₃ particles, the so-called coccoliths. An Emiliania huxleyi strain was cultivated to test and compare three fed-batch cultivation systems. A concept of separating the particles based on their different settling velocities is discussed. Fraction changes through ultrasonication are characterized.

For the design and optimization of silos it is necessary to monitor the behavior of bulk materials in the inner silo spaces. The monitoring of the dynamic process of the discharging of bulk material from silos using electrical capacitance tomography is a highly effective online method for obtaining detailed information about the behavior of the materials stored in enclosed spaces.

The flow of contaminated water through membranes causes fouling and leads to changes in the membrane transport properties. Understanding how these properties change during operation is critical for evaluating membrane performance. Herein, water flux reduction through a polysulfone membrane was modeled, and after validation of the model with experimental data, different properties were studied.

Commercial Portland cement (PC) was used as cheap binder to produce PC carbide slag (CS) pellets with enhanced mechanical strength. The carbonation conversion of the CS declined with the addition of PC, but the ability to resist sintering was improved. Extending the hydration time improved the CO₂ capture performance of the PCCS during pelletization.

Dry fractionation is widely applied to modify palm oil for improving its physical and chemical properties. Minor components, especially diacylglycerol (DAG), may influence the result. The effects of DAG on the cold stability characteristics of palm olein fractions were investigated by chromatographic purification. Essential information for palm oil industry for food application is provided.

Effective and efficient hydrogen storage technology is important for the hydrogen production sector and to increase the possibilities of using hydrogen as a future energy carrier. Two multistage hydrogen compression system models for hydrogen storage are proposed and their performances are evaluated based on energy and exergy analyses.

Ionic liquids (ILs) have no measurable vapor pressure at ambient temperatures but many practical applications of ILs are related to higher temperatures. An experimental and quantum-chemical investigation of the series of 1-alkyl-3-methylimidazolium ILs with trifluromethanesulfonate anion is presented. These results will facilitate chemical engineering calculations of processes involving ILs.

A novel mixotrophic biofilm reactor was developed to simultaneously remove nitrate, total organic carbon, and Mn(II) from wastewater. The effects of some key factors on mixotrophic denitrification were investigated and optimum conditions determined. Pseudomonas sp. SZF15 and Pseudomonas sp. H-117 played a primary role in the process of nitrate and Mn(II) removal in the mixotrophic biofilm reactor.

A simple procedure to estimate the mass transfer coefficients for CO₂ and N₂ in microporous activated carbon was developed based on uptake experiments typically used to obtain equilibrium isotherms. The estimated parameters helped to simulate breakthrough curves, which were compared to experimental data. An excellent match was observed, indicating the good reliablity of the presented method.

With technology development, wind/solar electricity-based renewable syngas could be synthesized and consumed in a green lifecycle where formic acid serves as a bridge via its synthesis from CO₂ and its reforming to CO. CO generation from formic acid would be technically advantageous over and economically comparative with some existing technologies as well as posing a clear ecological advantage.

Cryogenic air separation contributes significantly to greenhouse gas emissions due to its high energy demand. Reduction potentials of CO₂ emissions for full-tower and top-tower heat-integrated air separation columns compared to conventional air separation columns are evaluated, demonstrating their superior characteristics in terms of CO₂ emission potential, revenue, and economic feasibility.

Two unconventional precursors, seeds from red mombin and ice cream bean, were used to prepare ZnCl₂-activated carbons with well-developed microporous-mesoporous structures for potential usage in water treatment. The activated carbons showed excellent adsorption performance. Dispersion interaction was the limiting factor during methylene blue and methyl orange adsorption as examples.

Foaming is one of the most problematic issues which can generate operational barriers for effective removal of acid gases from sour natural gas. The effect of different impurities on foaming of aqueous diethanolamine solution and on the foam stability was analyzed. The impact of mixed impurities on foaming and foam stability of the aqueous amine solution were examined and discussed.

Cogeneration of gas-to-liquid products and ammonia is proposed which is self-sufficient with power and water and especially suitable for offshore applications. The suggested ammonia process is simple since it does not require separate shift reactors and a CO₂ capture unit. Cogeneration of ammonia will increase the total revenues by 50 %, which makes the combined process commercially attractive.

SO₂ emission from diesel exhaust means a serious threat to the environment and human health, necessitating enhanced desulfurization materials for dry desulfurization filters for diesel engines. MnO₂ was doped with various alkali metal ions to improve its SO₂ capture capacity. The SO₂ capture performance of MnO₂ could be significantly enhanced especially by modifying with lithium.

Alkaline metals have a catalytic effect on supercritical water gasification (SCWG). Potassium shows better catalytic activity than sodium; however, potassium is inactivated upon reaction with minerals in coal in SCWG. In situ protection of potassium is realized by adding Ca(OH)₂ under supercritical conditions.