A phased splitting off from high-strength concrete by electro-blasting method

Investigation of the phased splitting off from monolith concrete block via electro-blast technology have been described. The experiments were conducted using the high-current pulse generator with operating voltage up to 15 kV and maximum stored energy 126 kJ with initiation of the discharge in two boreholes (pair) at the same time. The electro-blasting were produced step by step three times. Each subsequent time was performed in the boreholes pair situated farther towards the free surface. Boreholes in a pair were drilled at a distance of 30-40 cm from each other, and of 25 cm apart from pairs, the depth of boreholes was 70 cm

Reducing Global Greenhouse Gas Emissions to Meet Climate Targets : A Comprehensive Quantification and Reasonable Options

A model is presented which covers the global greenhouse gas emissions (GHG emissions) and the energy consumption (fuels, electricity) in five sectors of end users, industry, transport, buildings, agriculture, and fugitive emissions. The electricity sector is also considered, but the associated GHG emissions are reallocated to the five end users. Different GHG reduction measures were calculated ranging from substitution of coal for electricity generation by renewables, electrification of road transport and buildings, restructuring of the sector industry to finally a 50% reduction of both food waste and meat consumption. To elucidate the consequences of global warming, future emission scenarios were also incorporated. One major conclusion is that the world can only reach the 2-degree climate target if electricity is only produced by renewables, and if transportation, buildings, and the industry are completely electrified by 2050. Compared to today, the electricity production by renewables will then rise by a factor of 11, and the total electricity demand by a factor of 2.4

Selective CO Methanation in H₂-Rich Gas for Household Fuel Cell Applications

Polymer electrolyte membrane fuel cells (PEMFCs) are often used for household applications, utilizing hydrogen produced from natural gas from the gas grid. The hydrogen is thereby produced by steam reforming of natural gas followed by a water gas shift (WGS) unit. The H2-rich gas contains besides CO2 small amounts of CO, which deactivates the catalyst used in the PEMFCs. Preferential oxidation has so far been a reliable process to reduce this concentration but valuable H2 is also partly converted. Selective CO methanation considered as an attractive alternative. However, CO2 methanation consuming the valuable H2 has to be minimized. The modelling of selective CO methanation in a household fuel cell system is presented. The simulation was conducted for single and two-stage adiabatic fixed bed reactors (in the latter case with intermediate cooling), and the best operating conditions to achieve the required residual CO content (100 ppm) were calculated. This was done by varying the gas inlet temperature as well as the mass of the catalyst. The feed gas represented a reformate gas downstream of a typical WGS reaction unit (0.5%–1% CO, 10%–25% CO2, and 5%–20% H2O (rest H2))