Utilization of Carbon Dioxide and Fluidized Bed Fly Ash in Post-Industrial Land Remediation

Abstract

The utilization of carbon dioxide and combustion products in cost- and energy-efficient technologies is an important element of creating sustainable energy systems, particularly in the transition period towards carbon neutrality and in light of the latest political developments, when solid fuels are still competing for a dominant role in securing energy supplies. Within the study presented, bituminous coal-derived fluidized bed fly ash samples of high calcium content, treated using a dry carbonation method under ambient conditions, were tested in terms of their specific properties to determine their usability in the preparation of injection mixtures for the filling of voids after shallow mining activities and other selected geo-engineering techniques. The study goes beyond the existing literature in terms of the carbonation method used, alkaline earth metal source, scale of the experiment, process conditions employed and product application studied. The results showed that the bituminous coal-derived fluidized bed fly ash, carbonated using the direct method adopted, may be successfully employed as the main solid component (over 82% w/w) of the injection mixtures for filling voids after shallow mining activities. The achievable compressive strength of a few MPa makes these materials applicable also in terms of ground strengthening in case it is required in light of the expected land development options to be employed. All principal materials used in the injection mixtures developed (carbonated fluidized bed fly ash, carbon dioxide, bottom ash) are industrial waste, and the carbonation method employed is simple and performed under ambient conditions, which reduces the required energy and cost input of filling mixture production, avoids the surface waste storage requirements, and contributes to the development of low energy-intensive carbon dioxide utilization and solid waste valorization methods.

Hydrogen Storage and Combustion for Blackout Protection of Mine Water Pumping Stations

“…In an ideal situation, operating electrolyzers, in addition to power supply, require about 9 dm 3 of water to obtain 1 kg of hydrogen. In practice, the water requirement of electrolyzers reaches 20 dm 3 of water per 1 kg of hydrogen [12,40]. To reduce the cost of purchasing water for the electrolysis process at the analyzed pumping station, the construction of a Mine Water Treatment Station (MWTS) was planned.…”

“…One way to reduce the impact is to generate energy from RESs [9][10][11]. The use of RESs depends on weather conditions, which poses many challenges [12,13]. On sunny days, the company's energy needs are met by photovoltaic farms.…”

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“…In Variant 5, all of the hydrogen produced is to be sold to the local community at the pump station's own fueling station at near-retail prices. In the baseline operation of the pumping station, the revenue from the sale of oxygen and hydrogen will be used to purchase energy to power the pumping station equipment during non-sunny periods (Howaniec et al, 2023;Wojtacha-Rychter et al, 2022). Selling the harvested hydrogen is a form of long-term storage for the excess electricity generated.…”

The Cost Reduction Analysis of Green Hydrogen Production from Coal Mine Underground Water for Circular Economy

“…The article presents the idea of using rainwater and process water, after appropriate purification, as a water source for the electrolysis process. This form of hydrogen production is the most advantageous from the point of view of zero-emission energy and transport [4][5][6].…”