Physicochemical properties of the potassium hydroxide-water system. Range: 55 to 85 weight percent and 120.degree. to 250.degree.

Vogel, Wolfgang; Routsis, K.; Kehrer, Victor J.; Landsman, D.A.; Tschinkel, Johann G.

doi:10.1021/je60035a002

Cited by 29 publications

(21 citation statements)

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“…The measured values for the 35 and 45 wt% solution are apparently slightly lower than those ones reported by Yushkevich [9]. The measured conductivity for the 55 wt% solution is slightly higher than this reported by Vogel et al [14] as shown in Figure 14 C. …”

Section: Conductivity Of Immobilized Aqueous Kohcontrasting

confidence: 59%

Electrical conductivity measurements of aqueous and immobilized potassium hydroxide

Allebrod

Chatzichristodoulou

Mollerup

et al. 2012

International Journal of Hydrogen Energy

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It is important to know the conductivity of the electrolyte from a alkaline electrolysis cell at a given temperature and concentration to reduce the polarization loss during electrolysis through optimal cell and system design. The conductivity of aqueous KOH at elevated temperatures and high concentrations was investigated using the van der Pauw method in combination with electrochemical impedance spectroscopy (EIS). Conductivity values as high as 2.7 S·cm -1 for 35 wt%, 2.8 S·cm -1 for 45wt%, and 2.8 S·cm -1 for 55 wt% concentrated aqueous solutions were measured at 200 °C. Micro-and nano-porous solid pellets were produced and used to immobilize aqueous KOH solutions. These are intended to operate as ion-conductive diaphragms (electrolytes) in alkaline electrolysis cells, offering high conductivity and corrosion resistance. The conductivity of immobilized KOH has been determined by the same method in the same temperature and concentration range. Conductivity values as high as 0.67 S·cm -1 for 35 wt%, 0.84 S·cm -1 for 45 wt%, and 0.73 S·cm -1 for 55 wt% concentrated immobilized aqueous solutions were determined at 200 °C. Furthermore, phase transition lines between the aqueous and aqueous + gaseous phase of aqueous KOH were calculated as a function of temperature, concentration and pressure in the temperature range of 100-300 °C, for concentrations of 0-80 wt% and at pressures between 1 and 100 bar.

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Section: Conductivity Of Immobilized Aqueous Kohcontrasting

confidence: 59%

Electrical conductivity measurements of aqueous and immobilized potassium hydroxide

Allebrod

Chatzichristodoulou

Mollerup

et al. 2012

International Journal of Hydrogen Energy

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“…Figure superimposes the well‐known variation of the melting point of water and sodium or potassium hydroxide mixtures temperature: The left axis is 100% water, while the right axis is 100% anhydrous hydroxide. Above the curves is a pure liquid phase, and below the curves the solution is in equilibrium with hydrated salts.…”

Section: Resultsmentioning

confidence: 99%

A New Technology for Efficient, High Yield Carbon Dioxide and Water Transformation to Methane by Electrolysis in Molten Salts

et al. 2016

Adv Materials Technologies

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This study presents a new green technology for the sustainable utilization of carbon dioxide. Synthetic methane, if produced effi ciently and with low carbon footprint, provides a ready replacement for natural gas in the existing energy, manufacturing, and transportation industries. The fi rst technology for the production of methane from CO 2 and water by molten electrolysis is demonstrated. The technology is more effi cient than alternative renewable methane production by microbial, aqueous, or solid oxide electrolysis, or than various photocatalytic processes. Methane is produced at 1000-fold the rate observed in photoelectrochemical systems, and without noble metals or an external hydrogen source. Added steam and CO 2 continuously renew the electrolyte. CO 2 and H 2 O are directly transformed by electrolysis at 97.4% current effi ciency at a constant current of 250 mA through 20 cm 2 iron and nickel electrodes in a 600 °C alkali carbonate/LiOH electrolyte at low (<2 V) energy. The electrolysis product is comprised of 64.9% methane, 34.8% H 2 , and 0.3% longer (than C1) hydrocarbons.

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“…Figure 9 shows the literature-known phase diagram of the system KOH–H 2 O under the assumption of saturation with K 2 CO 3 . [ 24 , 25 ]…”

Section: Resultsmentioning

confidence: 99%

Methanol Steam Reforming Promoted by Molten Salt‐Modified Platinum on Alumina Catalysts

et al. 2014

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We herein describe a straight forward procedure to increase the performance of platinum-on-alumina catalysts in methanol steam reforming by applying an alkali hydroxide coating according to the “solid catalyst with ionic liquid layer” (SCILL) approach. We demonstrate by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) and temperature-programmed desorption (TPD) studies that potassium doping plays an important role in the catalyst activation. Moreover, the hygroscopic nature and the basicity of the salt modification contribute to the considerable enhancement in catalytic performance. During reaction, a partly liquid film of alkali hydroxides/carbonates forms on the catalyst/alumina surface, thus significantly enhancing the availability of water at the catalytically active sites. Too high catalyst pore fillings with salt introduce a considerable mass transfer barrier into the system as indicated by kinetic studies. Thus, the optimum interplay between beneficial catalyst modification and detrimental mass transfer effects had to be identified and was found on the applied platinum-on-alumina catalyst at KOH loadings around 7.5 mass %.

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Physicochemical properties of the potassium hydroxide-water system. Range: 55 to 85 weight percent and 120.degree. to 250.degree.

Cited by 29 publications

References 0 publications

Electrical conductivity measurements of aqueous and immobilized potassium hydroxide

Electrical conductivity measurements of aqueous and immobilized potassium hydroxide

A New Technology for Efficient, High Yield Carbon Dioxide and Water Transformation to Methane by Electrolysis in Molten Salts

Methanol Steam Reforming Promoted by Molten Salt‐Modified Platinum on Alumina Catalysts

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