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Hydrogen production from rice husk was carried out via a two-stage system combining CLG (calcium looping gasification) using Ca(OH) 2 adsorbent in a bubbling fluidized bed and catalytic reforming with Ce–Ni/γAl 2 O 3 catalyst in a connected fixed bed. The results show that the maximum H 2 concentration (69.16 vol%) and H 2 yield (11.86 mmol g−1 rice husk) are achieved at Ca/C (Ca(OH) 2 to carbon molar ratio) = 1.5, H 2 O/C (H 2 O to carbon molar ratio) = 1.5, T g (gasification temperature) = 500 °C, T c (catalytic temperature) = 800 °C. The supplementation of fresh Ca(OH) 2 at Ca/C of 0.5 during calcination helps to activate the regenerated CaO by hydration, maintaining its carbonation activity and CO 2 adsorption. Ce–Ni/γAl 2 O 3 catalyst promotes water gas shift (WGS), steam methane reforming (SMR), and C 2 –C 3 hydrocarbons reforming, also exhibits excellent activity stability to maintain H 2 concentration and H 2 yield above 67.21 vol% and 11.67 mmol g−1 rice husk , respectively, during 5 lifetime tests. • Staged catalytic gasification of rice husk in a fluidized bed for H 2 -rich gas. • Ca(OH) 2 adsorbent promotes WGS and hydrocarbons reforming at a moderate temperature. • Fresh Ca(OH) 2 supplement during calcination activates regenerated CaO by hydration. • Ce–Ni/γAl 2 O 3 catalyst promotes WGS, SMR, and C 2 –C 3 hydrocarbons reforming reactions. • Ce–Ni/γAl 2 O 3 catalyst shows excellent activity stability with low carbon deposition. [Display omitted] [ABSTRACT FROM AUTHOR]

• Corrosion behavior of A3 carbon steel was evaluated by using both electrochemical testing techniques (potentiodynamic polarization technique and electrochemical impedance spectroscopy [EIS]) and immersion corrosion experiment (weight loss method) in 30 wt.% MEA and AMP-MEA blend amine solution systems. • The inhibition effect and mechanism of imidazoline, sodium metavanadate (NaVO3) and phosphoric acid, triethanolamine salt (P-TEA) in these two solvent systems were studied. • With the three inhibitors added, the Tafel curves exhibited varying degrees of rightward shift, indicating an increase in corrosion potential. NaVO3 and P-TEA could effectively raise the solution resistance and charge transfer resistance, thus achieving a corrosion inhibition effect. • AMP-MEA blends exhibits improved corrosivity performance with formation of a denser Fe2(OH)2CO3 protective layer on the surface of A3 carbon steel compared to MEA system at 100 °C. This could be illustrated by the higher bicarbonate concentration in AMP-MEA system. • The HSS and iron ion content of two solvent systems showed no significant difference and the HSS concentration order was sulfate > oxalate > glycolate > formate > acetate. The corrosion behavior of A3 carbon steel in 30 wt.% MEA and AMP-MEA (2:1) blended amine solutions, two typical CO 2 capture solvents for chemical absorption processes, was investigated. The inhibition effects of imidazoline, sodium metavanadate (NaVO 3), and phosphoric acid, triethanolamine salt (P-TEA) were evaluated using various electrochemical testing techniques and immersion corrosion experiments. Results showed that NaVO 3 exhibited the highest corrosion inhibition effect at a concentration level of 1000 ppm, while imidazoline showed limited effectiveness. Both NaVO 3 and P-TEA significantly increased solution resistance and charge transfer resistance, thereby enhancing corrosion inhibition. Additionally, AMP-MEA blends exhibited improved corrosion performance compared to MEA, with the formation of a denser protective layer on the surface of A3 carbon steel. Furthermore, experimental results revealed that NaVO 3 and P-TEA, instead of forming protective oxide or carbonate layers, formed complexes or chelates with iron ions in the solution. These compounds adsorbed onto the carbon steel surface, effectively preventing further corrosion. These findings provide valuable insights into the corrosion behavior of A3 carbon steel in amine-CO 2 H 2 O systems and underscore the potential of NaVO 3 and P-TEA as effective corrosion inhibitors. This knowledge is crucial for developing enhanced corrosion control strategies in related industrial applications. [ABSTRACT FROM AUTHOR]

A two-stage system involving alkaline thermal gasification of cellulose with Ca(OH) 2 sorbent and catalytic reforming with Ni/Fe dual-functional CaO based catalysts is proposed and applied to enhance H 2 production and in-situ CO 2 capture. The results show that the H 2 concentration is maximized at a considerably lower temperature (500 °C) than commercialized biomass gasification processes, reducing energy consumption. Sol-gel method is deemed better than impregnation method for its lower cost and higher-concentration H 2 production. Among the prepared catalysts, sol-NiCa catalyst exhibits the best performance in CO 2 absorption, resistance to carbon deposition, and cyclic stability, creating maximum H 2 concentration (79.22 vol%), H 2 yield (27.36 mmol g−1 cellulose), and H 2 conversion (57.61%). Introduction of Ni rather than Fe on the CaO based catalyst promotes steam methane reforming at moderate temperature range of 400–600 °C, generating low contents of CH 4 (5.38 vol%), CO 2 (4.82 vol%), and CO (10.58 vol%). [Display omitted] • A two-stage system involving alkaline thermal gasification and catalytic reforming. • Sol-gel shows higher-concentration H 2 production and lower cost than impregnation. • Introduction of Ni rather than Fe on CaO catalysts promotes SMR at 400–600 °C. • Sol-NiCa catalyst exhibits good carbon deposition resistance and cyclic stability. • Maximum H 2 concentration (79.22 vol%) is achieved at moderate temperature of 500 °C. [ABSTRACT FROM AUTHOR]

Abstract To study the characteristics of positive and negative DC discharge under coal pyrolysis gas media at 20 °C–600 °C, the I V characteristics and the current composition are analyzed under different conditions. Due to the difference of ionization mechanism, the corona onset voltage of negative corona is lower than that of positive corona under air gas medium. Under non-electronegative gas media, no corona occurs during negative discharge. However, during positive discharge, with the increase of output voltage, three types of discharge are successively observed, namely corona, glow and arc. Under N 2 gas media and at 400 °C, the maximum collection efficiency of positive electrostatic precipitator is 98%, while that of negative electrostatic precipitator is 82%. When the collection efficiency is 70%, the energy consumption index of negative electrostatic precipitator is about 200 times higher than that of positive electrostatic precipitator. A linear relationship between I/V and V is observed and the ionic mobility can be calculated through the slope. At 350 °C, the ionic mobility under H 2 gas medium is 5.25 cm2/(V*s) while the ionic mobility under N 2 gas medium is 0.1 cm2/(V*s). The ionic mobility is proportional to the absolute temperature according to the discharge experimental data at 350 °C–600 °C. The factor β i , which is only related to gas media, is 0.0001653 cm2/(V*s*T) for N 2 and 0.0087308 cm2/(V*s*T) for H 2. These results assist in understanding the property of ESP at high temperatures. Graphical abstract Unlabelled Image Highlights • Under coal pyrolysis gas medium, corona only occurs in positive discharge. • Under N 2 gas medium, the positive ESP is better than negative ESP. • The ionic mobility under H 2 is about 52 times higher than that of N 2. [ABSTRACT FROM AUTHOR]

Highlights • Novel type of biphasic solvent with low costs and high cyclic capacity is proposed. • DEEA-AEEA solvent shows regeneration energy as low as 2.58 GJ/tCO 2. • Phase split time as short as minutes enables fast phase separation. • Driving and resistance forces dominating the phase split dynamics are analyzed. • CO 2 reactions and phase split mechanism are revealed by NMR analysis. Abstract Using biphasic solvents for carbon dioxide (CO 2) capture is regarded as a promising technology to drastically reduce the regeneration energy. However, this technology hasn't been put into commercial application due to lack of the biphasic solvents with high stabilities and low costs. To overcome this challenge, we developed a novel type of biphasic solvent based on alkanolamine-alkanolamine blends, i.e., aqueous blends of 2-(diethylamino)-ethanol (DEEA, 50 wt%) and monoethanolamine (MEA, 25 wt%) or 2-((2-aminoethyl) amino) ethanol (AEEA, 25 wt%). The aqueous DEEA-AEEA solvent demonstrated a cyclic capacity as high as 0.64 mol CO 2 /mol which is significantly higher than those of 30 wt% MEA and other reported biphasic solvents. In addition, a phase split time as short as a few minutes is obtained. The phase split dynamics were analyzed to investigate the effects of CO 2 loading, temperature, gas flow rate and height-to-diameter ratio. Quantitative 13C NMR analysis was then performed to reveal the reaction and phase split mechanism of CO 2 absorption in the DEEA-AEEA solvent. It indicated that the reaction of AEEA with CO 2 dominated at the beginning of CO 2 absorption and the products are formed as carbamates. Then, DEEA began reacting with CO 2 to yield bicarbonate and carbonate. The phase split mechanism indicated that the reaction products of carbamates and HCO 3 −/CO 3 2− migrated to the lower phase while DEEA and unreacted AEEA migrated to the upper phase. Finally, the cyclic tests were repeated and the energy consumption was evaluated. The regeneration energy of the biphasic solvent, without process optimizations, is 2.58 GJ/tCO 2 , which is 32% lower than that of the traditional 30 wt% MEA solvent. [ABSTRACT FROM AUTHOR]

• Innovative two-stage "BMED+ED" electrodialysis amine reclaiming unit. • Overall improvement of reclaiming performance on HSS removal rate, amine loss rate, energy consumption etc. • The causes on removal efficiency difference of various HSSs were analyzed. • Economic analysis of three membrane configurations was analyzed and compared. Due to the degradation reaction and the presence of acidic impurities (HCl, SO 2 , etc.) in the flue gas, heat stable salts (HSS) are widely present in the aqueous amine solvent for post-combustion CO 2 capture. Accumulation of HSS in the solvent can lead to decreased absorption capacity and even corrosion of equipment in post-combustion capture (PCC) pilot plants. This study presents a novel "BMED+ED" two-stage electrodialysis unit for the efficient removal of HSS, including glycolate, formate, Cl−, and SO 4 2−, from degraded amine solvent with an initial loading of approximately 0.38 mol/mol taken from the solvent loop of a PCC pilot plant after over 1000 hours of operation at real conditions. Experimental results showed that 94.93% of HSSs were removed with an initial HSS concentration of approximately 1920 ppm. The amine loss rate in the two-stage electrodialysis unit was much lower than that in a conventional ED unit, as protonated amine is further converted to organic amines by bipolar membrane electrodialysis. The energy consumption of the two-stage electrodialysis unit was 0.1643 kWh/L amine solvent, and the total cost for amine reclaiming was 1.8145 $/kg amine. This method effectively addressed the challenges of high amine loss rate in the traditional ED treatment process and hazardous wastewater disposal. [ABSTRACT FROM AUTHOR]

Pressurized oxy-fuel combustion is recognized as the second generation of oxy-fuel combustion technology that can facilitate carbon capture and reduce energy consumption, while coal and biomass combustion is also an effective way to decrease carbon emissions. This study innovatively integrates these two clean combustion technologies and investigates the effects of pressure and blending ratio on the combustion characteristics (ignition, combustion rate, volatile combustion, semi-coke combustion, burnout) of coal, biomass and their blends using an advanced magnetic levitation HPTGA. The results show that pressurization can improve the combustion rate of coal and biomass, but it will cause ignition delay when system pressure exceeds 0.5 MPa. The effect of pressure on combustion characteristics is both facilitative and inhibitive, in terms of reaction kinetics, pressurization can significantly promote combustion but it also plays a role in inhibiting oxygen diffusion, the competition between the two effect leads to an optimum value of pressure in the combustion performance of the blends, which is about 1 MPa. Biomass is more sensitive to pressure than coal, and pressurization changes the ignition mode of biomass. In addition, a new synergy index is defined to quantify the synergistic effect of the whole co-combustion process. Pressurization could suppress both catalytic and non-catalytic mechanisms in the co-combustion process, and different sensitivities of biomass and coal to pressurization lead to more significant differences in combustion time and temperature interval compared with normal pressure, all these factors contribute to negative synergistic effect under pressurization. • Pressurized oxy-fuel combustion performance of coal and biomass individually and co-firing was explored in 0.1–2.0 MPa. • Pressurization changes the ignition mechanism of biomass, whereas coal consistently exhibits heterogeneous ignition in 0.1–2.0 MPa. • A new synergy index was defined to quantify the synergistic effect of the whole co-combustion process. • The pressurized co-combustion presents a negative synergistic effect, which tends to increase with the rising pressure. [ABSTRACT FROM AUTHOR]

An experimental system composed of microscopic visualization and high-speed photography was developed to observe the relative motion and agglomeration characteristics between fine particles and a large glass particle directly. The large glass particle was fixed in the middle of a rectangular flow channel, fine particles were generated by burning sandalwoods in a buffer tank. The observations showed that fine particles flowed over the large glass particle when they were uncharged. When the large particle and fine particles carried charge of different polarities, an obvious attraction between them was observed. When the large particle and fine particles carried charge of the same polarity, the fine particles showed two kinds of motion characteristics, depending on the charge number they carried. When fine particles carried a small number of charge, they still attracted each other. In contrast, fine particles carrying a large number of charge led to repelling. The induced dipole force was taken into consideration to explain the observed phenomenon. A simulation of the movements of the fine particles considering the combined effects of the induced dipole force, the Coulomb force, the drag force and the electric field force was carried out. The simulation results matched the experimental results well. [ABSTRACT FROM AUTHOR]

• Novel alkanolamine-based biphasic solvent with low regeneration energy and viscosity is proposed for CO 2 capture. • Tertiary amine 3-(dimethylamino)propan-1-ol(3DMA1P) is firstly introduced to decrease regeneration energy. • Phase separation mechanism is revealed by NMR and LogP analysis. • Molecular dynamics simulation is applied to study liquid structure and monitor the phase separation process. Biphasic solvents for CO 2 capture have received significant attention due to their potential for energy conservation. However, traditional biphasic solvents result in highly viscous CO 2 rich-phases and high amine losses. To overcome these drawbacks, we have developed a novel alkanolamine-based biphasic solvent by blending 2-(methylamino) ethanol (MAE), 3-(dimethylamino)propan-1-ol (3DMA1P), diethylene glycol dimethyl ether (DGM), and water. The aqueous MAE/3DMA1P/DGM solvent showed a cyclic capacity of 0.45 mol CO 2 /mol amine, which is 1.8 times that of monoethanolamine (MEA), and a desorption rate and regeneration efficiency twice those of MEA. The viscosity of the biphasic solvents can be reduced to 13.12 mPa⋅s at 313 K, which is lower than that of reported biphasic solvents. The evaluated regeneration energy was 2.33 GJ/ton CO 2. Cation chromatography measurements revealed the tendency of MAE to accumulate in the CO 2 -rich phase with increasing CO 2 absorption loading. Quantitative 13C NMR analyses were performed to investigate the species distribution in both phases, and DGM was found to be the major component of the CO 2 -lean phase. Different solubilities of the MAE molecules and MAE carbamate in DGM resulted in phase separation. Molecular dynamics (MD) simulations on the CO 2 -unloaded and CO 2 -loaded solutions verified the phase separation mechanism. MAE molecules tended to cluster, and the interactions between MAE and DGM dropped significantly, with increasing DGM concentration. [ABSTRACT FROM AUTHOR]