Thermogravimetric analysis and process simulation of oxy-fuel combustion of blended fuels including oil shale, semicoke, and biomass

Abstract

Summary Oxy‐fuel (OF) combustion is considered as one of the promising carbon capture and storage technologies for reducing CO2 emissions from power plants. In the current work, the thermal behaviour of Estonian oil shale (EOS) and its semicoke (SC), pine saw dust, and their blends were studied comparatively under model air (21%O2/79%Ar) and OF (30%O2/70%CO2) conditions using thermogravimetric analysis. Mass spectrometry analysis was applied to monitor the evolved gases. The effect of SC and pine saw dust addition on different combustion stages was analysed using kinetic analysis methods. In addition, different co‐firing cases were simulated using the ASPEN PLUS V8.6 (APV86) software tool to evaluate the effects of blending EOS with different biomass fuels of low and high moisture contents. The specific boiler temperatures of each simulated case with the same adjusted thermal fuel input were calculated while applying the operation conditions of air and OF combustion. According to the experiment and process simulation results, the low heating value and high carbonate content of SC brings along endothermic decomposition of carbonates, which negatively affects the heat balance during the conventional co‐combustion of EOS with SC. Instead, firing of EOS with SC and biomass in OF process can be an effective solution to reduce the environmental impact in terms of the reduction of CO2 emissions and ash. Furthermore, the sensible heat from SC can positively affect the energy balance of the system as the endothermic effect of decomposition of CaCO3 (for both EOS and SC) can be avoided in OF combustion.

Oxidation Characteristics of the Semicoke From the Retorting of Oil Shale and Wheat Straw Blends in Different Atmospheres

“…So is the SO 2 emission. This is consistent with the findings of other researches [13,[29][30][31] and is ascribed to the direct sulphuration of carbonates as Reaction (7) shows, rather than to the CaO-SO 2 reaction in air as Reaction (12) reveals. As Chen et al [32] have indicated, the formation of calcium oxide is accompanied with the decrease of BET-N 2 surface area and average pore size.…”

Cost‐competitive methane steam reforming in a membrane reactor for H 2 production: Technical and economic evaluation with a window of a H 2 selectivity

“…Process simulation is widely used to analyze chemical processes of interest and to find optimized operating conditions based on the process simulation results obtained from material and energy balances of the whole system. Currently, commercial process simulators are being used as robust tools for chemical process simulation such as HYSYS® (AspenTech, Inc., Beford, MA, USA), Aspen Plus® (AspenTech, Inc., Beford, MA, USA), Unisim Design® Suite (Honeywell, Morris Plains, NJ, USA), and CHEMCAD (Chemstations, Inc., Houston, TX, USA) . Among them, HYSYS was selected in this paper as an appropriate process simulator for a PBR and an MR because it is well opted for gas processing technology.…”

Fabrication of Eco-Friendly Superabsorbent Composites Based on Waste Semicoke

“…Oil shale semicoke (SC) is a byproduct from the thermal processing of oil shale consisting of the stable carbonic matter and other inorganic minerals, including quartz, kaolinite, hematite, carbonate, and others [ 28 ]. Due to the current technology not fully utilizing the SC by high value-added approach, many problems afflict the coal and petrochemical enterprises seriously, such as the high waste of land resources and potential threat to the environment [ 29 , 30 ]. Encouragingly, a great deal of research has investigated the utilization of SC in several fields in recent decades, and provided many basic datum and methods for effective recycling of SC.…”