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Based on the Stochastic Impacts by Regression on Population, Affluence, and Technology (STIRPAT) model, the impact factors of industrial carbon emission in Nanjing were considered as total population, industrial output value, labor productivity, industrialization rate, energy intensity, research and development (R&D) intensity, and energy structure. Among them, the total population, industrial output value, labor productivity, and industrial energy structure played a role in promoting the increase of industrial carbon emissions in Nanjing, and the degree of influence weakened in turn. For every 1% change in these four factors, carbon emissions increased by 0.52%, 0.49%, 0.17% and 0.12%, respectively. The industrialization rate, R&D intensity, and energy intensity inhibited the increase of industrial carbon emissions, and the inhibiting effect weakened in turn. Every 1% change in these three factors inhibited the increase of industrial carbon emissions in Nanjing by 0.03%, 0.07%, and 0.02%, respectively. Then, taking the relevant data of industrial carbon emissions in Nanjing from 2006 to 2020 as a sample, the gray rolling prediction model with one variable and one first-order equation (GRPM (1,1)) forecast and scenario analysis is used to predict the industrial carbon emission in Nanjing under the influence of the pandemic from 2021 to 2030, and the three development scenarios were established as three levels of high-carbon, benchmark and low-carbon, It was concluded that Nanjing's industrial carbon emissions in 2030 would be 229.95 million tons under the high-carbon development scenario, 226.92 million tons under the benchmark development scenario, and 220.91 million tons under the low-carbon development scenario. It can not only provide data reference for controlling industrial carbon emissions in the future but also provide policy suggestions and development routes for urban planning decision-makers. Finally, it is hoped that this provides a reference for other cities with similar development as Nanjing.

Most of the time char particles in commercial FB units encounter considerably lower oxygen concentrations than that in the entrance, say between 2% and 10%, and the effects of the oxy-fuel atmosphere on the conversion history of char particles need to be clearly treated under these conditions. In the present work, an experimental study of combustion of bituminous coal char was carried out in a laboratory FB in O 2 /CO 2 and O 2 /N 2 atmospheres under simulated FB combustor conditions at O 2 concentrations of 4–10% v/v, bed temperatures of 800–900 °C and char particle sizes of 2–8 mm by continuously measuring the concentrations of O 2 and CO in the flue gas. The results indicate that the conversion of char is controlled by diffusion of O 2 in the boundary layer of the particle in O 2 /CO 2 and O 2 /N 2 environments and that the gasification of char in O 2 /CO 2 is limited by chemical kinetics. A char conversion model, taking into account the mass transfer from the bed to the particle and the gasification kinetics of char, was built, based on the experimental results and the intrinsic reactivity of char obtained in TGA tests. Simulations, carried out under the same conditions as in the FB experiments, give good agreement in terms of burnout time and instantaneous reactivity during the conversion of single particles. Simulated results prove that the low diffusivity of O 2 in CO 2 is the main reason for the decreased reaction rate of the char particle in O 2 /CO 2 compared with O 2 /N 2 . The contribution of gasification to the consumption of char is more notable at high bed temperature (900 °C) and coarse particles (8 mm), particularly at lower oxygen concentration (4–6% v/v). [ABSTRACT FROM AUTHOR]

• Alkali metal salts promoted MgO pellets were prepared for CO 2 capture. • Sacrificial pore-forming templates were employed to improve CO 2 uptakes. • Template modification improved pore structure and facilitated CO 2 bulk diffusion. • Structure-performance relationships of AMS-MgO-P were unraveled. • AMS-MgO-P-MC exhibited high CO 2 uptake and desirable mechanical property. Alkali metal salts (AMS) promoted MgO with high CO 2 uptakes represents a promising adsorbent candidate for CO 2 capture. The AMS-MgO composite adsorbents are facing the challenges of increased pressure drop or elutriation when employed in dual fixed-bed reactor or twin circulating fluidized-bed configurations. Granulation by the extrusion-spheronization technique represents an effective problem-solving strategy. However, textural properties and CO 2 uptakes of MgO-based adsorbent pellets might be adversely affected by the granulation process. In this work, AMS-MgO composite adsorbent pellets were prepared by the extrusion-spheronization method. Citric acid (CA), ammonium bicarbonate (AB), urea (UA) and microcrystalline cellulose (MC) were employed as pore-forming templates to improve the porous structures and CO 2 uptakes of the AMS-MgO pellets. CO 2 uptakes and adsorption kinetics of the adsorbent pellets were studied using a fixed-bed reactor. Effects of granulation and pore templating on the structure-performance relationships of the AMS-MgO pellets were unraveled. Granulation had resulted in the remarkable decrease in CO 2 uptake from 10.87 to 4.24 mmol CO 2 /g due to the impaired textural parameters. The employed sacrificial templates endowed the AMS-MgO pellets with enhanced CO 2 uptakes and improved carbonation kinetics. This was associated with extended surface area and expanded pore structures due to gas liberation in the pyrolysis of templates, which had facilitated the kinetics of CO 2 bulk diffusion. The desired AMS-MgO-MC pellet modified with MC template showed a high CO 2 uptake of 7.54 mmol CO 2 /g in 50%CO 2 at 340 °C, and its CO 2 uptake was stabilized around 5.0 mmol CO 2 /g within 20 cycles. Besides, the AMS-MgO-MC pellet also exhibited good mechanical properties. The results will guide the rational design of highly efficient and robust MgO-based adsorbent pellets for CO 2 capture applications. [ABSTRACT FROM AUTHOR]

Abstract: Biomass fast pyrolysis is one of the most promising technologies for biomass utilization. In order to increase its economic potential, pyrolysis gas is usually recycled to serve as carrier gas. In this study, biomass fast pyrolysis was carried out in a fluidized bed reactor using various main pyrolysis gas components, namely N2, CO2, CO, CH4 and H2, as carrier gases. The atmosphere effects on product yields and oil fraction compositions were investigated. Results show that CO atmosphere gave the lowest liquid yield (49.6%) compared to highest 58.7% obtained with CH4. CO and H2 atmospheres converted more oxygen into CO2 and H2O, respectively. GC/MS analysis of the liquid products shows that CO and CO2 atmospheres produced less methoxy-containing compounds and more monofunctional phenols. The higher heating value of the obtained bio-oil under N2 atmosphere is only 17.8MJ/kg, while that under CO and H2 atmospheres increased to 23.7 and 24.4MJ/kg, respectively. [Copyright &y& Elsevier]