Search results for "elektrolyysi"
showing 4 items of 4 documents
Utilization of waste sodium sulfate from battery chemical production in neutral electrolytic pickling
2021
Several industrial activities produce metal sulfates, which are controlled by strict limitations for wastewater concentrations of sulfate. One emerging area where these activities occur is the production of lithium-ion battery chemicals in which sodium sulfates are formed because of cathode precursor co-precipitation. Several solutions for sulfate removal exist, but one option is to reuse the sulfate side stream in other processes to increase circular economy and atom efficiency. In this paper, the reuse of sodium sulfate solution in a steel industry pickling solution is considered. Neutral electrolytic pickling experiments were carried out to compare the pickling behavior of the electrolyt…
Coadsorption of NRR and HER Intermediates Determines the Performance of Ru-N4 toward Electrocatalytic N2 Reduction
2021
Efficiency of the electrochemical N2 reduction reaction (NRR) to ammonia is seriously limited by the competing hydrogen evolution reaction (HER) but our current atomic-scale insight on the factors controlling HER/NRR competition are unknown. Herein we unveil the elementary mechanism, thermodynamics, and kinetics determining the HER/NRR selectivity on the state-of-the-art NRR electrocatalyst, Ru-N4 using constant potential density functional theory calculations (DFT). The calculations show that NRR and HER intermediates coadsorb on the catalyst where HER is greatly suppressed by the NRR intermediates. The first reaction step leading to either *NNH or *H determines the selectivity towards NRR…
Kuparin, hopean ja palladiumin talteenotto piirilevyjätteestä
2017
Tutkielmassa käsitellään rikkihapon käyttöä sähkö- ja elektroniikkaromuun kuuluvan piirilevyjätteen liuotuksessa ja rikkihappoon liuenneiden metallien talteenottoa erilaisin menetelmin. Sähkö- ja elektroniikkaromu on pian maailman suurimmaksi kasvava jätevirta, jolla on sekä ympäristöllisiä että taloudellisia vaikutuksia, jos romun sisältämiä metalleja ei saada kierrätettyä. Elektroniikkalaitteiden piirilevyt sisältävät noin 60 % metalleja, joiden talteenottamiseksi on lähiaikoina tehty paljon tutkimusta. Piirilevyjen sisältämiä arvokkaita metalleja ovat erityisesti kulta, hopea, palladium ja platina. Rikkihappo on yleisin teollisuudessa käytetty happoliuotin, …
Analysis of 5 MW hydrogen power system with thermal energy storage
2013
Energy storage for further energy production has become a feasible option to deal with energy fluctuation, energy over production and energy shortcomings caused by the penetration of renewable energies. Hydrogen storage has been studied through mathematical model and simulation to predict its performance and technological feasibility. This thesis presents a model where a 5 MW electrolysis plant is simulated. The power plant consists on an electric input from renewable sources like wind turbines or photovoltaic panels. Electrolysis is done by a solid oxide cell that also produces electric power working as fuel cell. Thermal energy storage is added in order to recover heat released by the cel…