CO2 Gasification Reactivity Research Articles

Structure characteristics and gasification reactivity of co-pyrolysis char from lignocellulosic biomass and waste plastics: Effect of polyethylene

The rate limiting stage is char reactivity during gasification that can be influenced by its physicochemical structural characteristics. In this study, the effects of feedstock share, rice straw (RS) and polyethylene (PE), on the physicochemical properties and gasification reactivity of chars were investigated and their relationships were discussed. The char gasification reactivity was investigated via isothermal experiments using a thermal analyzer. The results indicated that the PE addition improved the specific surface area (SSA) and pore volume (Vp) of the char obtained from co-pyrolysis RS with PE. The SSA of the char increased by 1.31 times when the PE content was 60 wt%, compared with that of RS char. The order degree and gasification reactivity of the co-pyrolysis char samples increased with increasing PE content beyond 40 wt%. The char reactivity in the early stage of co-gasification was primarily determined by the order degree of carbonaceous and pore structure. The char reactivity in the later stage was influenced by these two factors and the silicon dioxide content could inhibit the char co-gasification reactivity.

Effect of CO2 Gasification on Nitrogen Oxide Emission in Oxy-Fuel Combustion.

Due to the cumulative effect of the recycled flue gas in oxy-fuel combustion, the reduction of NO has become the focus of research in which the role of CO2 gasification has a nonnegligible effect. In this article, the heterogeneous gasification mechanisms of CO2 on coal char during oxy-fuel combustion were studied by density functional theory and transition-state theory. The zigzag char model and char(N) model were selected to investigate the CO2 adsorption and gratification reactions at the molecular level. By comparison, the CO2 gasification reaction is preferred to occur on the zigzag char model with a reduction in the energy barrier and an increase in the reaction rate. When considering char nitrogen conversion, the gasification reaction is more prone to releasing NO first, leading to the contraction of the aromatic ring and the generation of CO at high temperatures. Therefore, the study further highlights the promoting role of CO2 gasification on the homogeneous and heterogeneous reduction of NO, which is mainly reflected in the reduction effect of CO. Moreover, it also accelerates the consumption of coal char and NO formation, which is favorable for the reduction reactions to a certain extent.

Direct Liquefaction of South African Vitrinite- and Inertinite-Rich Coal Fines.

In this investigation, coal fines enriched with inertinite were used for direct liquefaction experiments. For comparison, a vitrinite-rich coal typically utilized in coal-to-liquid processes was also employed. To assess the impact of mineral matter content, demineralization was used to remove most of the inorganic constituents. The findings revealed that the inertinite-rich coal exhibited lower liquefaction conversions due to a reduced proportion of reactive macerals and elevated levels of inorganic mineral matter. These conversion values exhibited a strong correlation with the quantity of reactive macerals present in the parent coals. For the inertinite-rich coal, the presence of inorganic mineral matter impeded the liquefaction process but facilitated the CO2 gasification reactions of the derived chars. To evaluate their potential in gasification processes, CO2 gasification experiments were conducted and the reactivities and apparent gasification activation energies of both coal chars, liquefaction residue chars, and preasphaltene and asphaltene (PAA) chars were calculated. These calculations were carried out using the random pore model (RPM) and volumetric reaction model (VRM). The chemistry, reactivity, and kinetics of residue gasification conversion are not thoroughly understood, yet they hold significant importance in optimizing syngas production within gasification processes. The findings from this work highlight significant differences in liquefaction conversion values, product distribution, and composition. These differences are influenced by factors such as maceral composition, inorganic mineral matter content, hydrogen-donor capabilities of the solvent, and liquefaction reaction temperatures. Additionally, these variables affect the CO2 gasification reactivity of liquefaction solid residue chars.

Structural characterization of char during co-gasification from torrefied sludge and Yangchangwan bituminous coal

The present study aims to investigate the physico-chemical structural evolution characteristics of char structure of CO2 atmosphere torrefaction pretreated sludge with Yangchangwan bituminous coal (YC) during co-gasification. The co-gasification reactivity of torrefied sludge and YC was measured using a thermogravimetric analyzer. The co-gasification reactivity of torrefied sludge with YC was thoroughly explored in depth by in situ heating stage microscope coupled with traditional characterization means of char sample (Scanning electron microscope, nitrogen adsorption analyzer, laser Raman spectroscopy). The results show that the gasification reaction rate of sludge treated under CO2 atmosphere and coal blended char was better than other char samples at 1100–1200 °C. The torrefied sludge under CO2 atmosphere promoted its thermal decomposition to the maximum extent, so that it eventually was transformed into a large number of small broken particles. The specific surface area and ID1/IG ratio of blended char of torrefied sludge under CO2 atmosphere and YC were 1.70 and 1.07 times higher than that of YC, respectively. The in situ technique revealed that YC char with the addition of torrefied sludge undergo gasification by shrinking core modes and the presence of obvious ash melting flow phenomenon. It was more obvious than that of YC.

Some new insights into the kinetic compensation effect in different diffusion-controlled domain for char-CO2 gasification

The CO2 gasification reaction of lignite and coffee char are conducted at 1098–1173 K and 0.025–0.1 MPa CO2 via thermogravimetry analysis (TGA). The calculation methods of the activation energy and pre-exponential factor are further compared and analyzed. The activation energy and pre-exponential factor in the chemical-controlled domain, the external diffusion-controlled domain and the bed diffusion-controlled domain are measured to investigate the relationship between the kinetic compensation effect and mass transfer limitations. Results reveal that the normalized power-law rate equation can provide reliable kinetic parameters due to PCO2n ≠ constant (PCO2n represents the partial pressure term) at different temperatures and f(X) ≠ constant (f(X) represents the mechanism function term) at different char conversion. In the chemical-controlled or the external diffusion-controlled domains, coffee grounds char (CGC) and lignite char (LC) exhibit similar activation energies and pre-exponential factors in the char conversion range of 0.2–0.8. In the bed diffusion-controlled domain, the activation energy and pre-exponential factor increase and then decrease during the reaction process. An evident kinetic compensation effect was observed between E and ln(A0) throughout the conversion process with bed diffusion and among data from experiments with and without diffusional limitations, showing its dependence on mass transfer limitations.

Large-scale simulation of CO2 gasification reaction with mass transfer for metallurgical coke: Comparison with lab-scale experiment at 1373 K in early stage

The large-scale simulation of gasification using a highly resolved coke model is a powerful tool for predicting structural changes in metallurgical coke in a blast furnace. The objective of this study was to evaluate the accuracy of a numerical simulation using the results obtained from laboratory-scale gasification experiments. For the experiment, a cylindrical coke sample with a radius of 20 mm was gasified using CO2 gas at 1373 K in a coke gasification reaction furnace until the conversion reached 0.2. In addition, a numerical simulation of the coke model developed from X-ray computer tomography images of the coke sample before the reaction was conducted at 1373 K. Three low-resolution coke models were developed using the full-resolution coke model. The reaction rate and the coke structure after reaction were compared between the experiment and the numerical simulation. As a result, the prediction accuracies of reaction rate and structural change decreased with decreasing the image resolution as overall trend.

Gasification behavior and kinetics of chars derived from coal pyrolysis in a CO-containing atmosphere

Char gasification enables clean and efficient utilization of low-rank coal resources. The CO2 gasification behavior and kinetics of char samples produced via low-rank coal pyrolysis under the N2 and CO-containing atmospheres (char-N2 and char-CO) were investigated based on a series of thermogravimetric experiments, and the physicochemical structure of chars were characterized via Raman diffraction, X-ray diffraction, and CO2 adsorption methods, respectively. The apparent activation energies (Ea) of char-N2 and char-CO were obtained using the Flynn–Wall–Ozawa method and the reaction mechanism was determined via the Malek method. The results indicate that the graphitization and order degrees of the carbon chemical structure of char-CO are higher than those of char-N2 below gasification temperature (approximately 850 °C), whereas the specific surface area of char-CO is higher than that of char-N2 before gasification. Char-CO gasifies faster than char-N2 owing to its developed pore structure, and the gasification activation energy is lower than that of char-N2 (from 450 °C to 650 °C, the activation energy of char-N2 is 186.3 kJ mol−1, 192.4 kJ mol−1, and 203.6 kJ mol−1, and that of char-CO is 175.8 kJ mol−1, 187.5 kJ mol−1, and 199.1 kJ mol−1, respectively). The CO2 gasification reaction process of char-N2 and char-CO can be explained using a three-dimensional diffusion model. Moreover, the ash content in coal char affects the diffusion of reaction carrier gas and gas products during the gasification process, indicating that diffusion is the primary limiting factor in coal char CO2 gasification.

Coke evolution during the air- and oxy-firing regeneration of a spent Ni/ZnO sulfur adsorbent

Reactive adsorption desulfurization (RADS) is an effective desulfurization technology in refineries to reduce the sulfur contents in oil products. To ameliorate the desulfurization technology, the evolution of coke was first studied in the air-firing regeneration of a typical spent Ni/ZnO sulfur adsorbent used in RADS. Efforts were made to elaborate the conversion of carbon and sulfur during the oxy-firing regeneration of the spent adsorbent to test the possibility of applying that carbon capture technology – oxy-fuel combustion to the sulfur adsorbent regeneration. A lab-scale drop-tube furnace was employed to conduct the combustion experiments; and the speciation of carbon and sulfur in the regenerated adsorbents was characterized by advanced techniques including near-edge X-ray absorption fine structure (NEXAFS), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The catalytic role of metals (Ni/Zn) in the coke combustion was also verified by acid leaching and temperature-programmed oxidation (TPO) experiments. It has been founded that the carbonaceous materials deposited on the adsorbent comprise five groups, including polyaromatic and graphitic carbon with a fraction of around 27 mol% of the entire carbon, and the other groups which are mostly light aliphatic compounds and oxygen-containing functional groups. During the air-firing regeneration process, most of the light coke species were oxidized into oxygenated intermediates and then desorbed as CO and CO2, with a small portion being polymerized into heavy molecules. Oxy-firing regeneration was verified to improve the efficiency of coke combustion due to the metal-catalyzed CO2 gasification reaction and improved the sulfur conversion under the oxygen-lean condition such as 3 vol% O2 in CO2. The carbon conversion increased from 23% in 3%O2/N2 to 31% in 3%O2/CO2 at 510 ℃. In the meantime, the sulfur conversion was also increased from 50% to 57% at 750 ℃, which is probably due to that the CO2 gasification of coke alleviated the competition of oxygen between carbon and sulfur.

Prediction of reduction products in the preheating process

Under the current requirements of environmental protection, carbon peaking and carbon neutrality goals, the capacity of the new energy interconnection network is increasing day by day. The thermal power unit requires the ability of rapid load adjustment to meet the requirements of real-time power balance. However, when the unit is in a variable load condition, the denitrification system is inefficient or even inoperable. The NOx emission is large, which makes it difficult to meet environmental protection requirements. In this study, a new method for predicting reductive products in the preheating process is proposed, introducing the gasification mechanism into the pulverized coal preheating process. The effects of air coefficient on combustion temperature, velocity, O2, CO2, CO, CH4, and H2, volatile matter and NOx emission are investigated by numerical simulation. It is demonstrated that the gasification mechanism is applicable to predict the reduction products and NOx during preheating. Internal combustion burners can stabilize the precipitation of volatile matter, CH4, CO, and H2. The burner outlet temperature and flow rate decrease with decreasing air coefficient. The local maximum concentration of volatile matter and CH4 are 8.3 vol.% and 2.54 vol.%, respectively. The CO concentration increases with decreasing air coefficient under the effect of CO2 gasification reaction. When the air coefficient is 0.33, the NOx concentration at the burner outlet is 2.8 mg/Nm3 (at 6% O2).

A rational and feasible approach to the co-management of condensates from biomass torrefaction and carbon-rich fly ash from fluidized-bed coal gasification

This study explored a promising approach to the co-management of torrefaction condensates (TCs) from biomass and carbon-rich fly ash (FA) derived from an industrial fluidized-bed coal gasifier. TC was a low-quality liquid product consisting mostly of water and a small amount of organic acids and other oxygenated organics. FA was the ultra-fine particulates with high carbon content (40–70%) and some extreme characteristics such as ultra-low volatiles, low reactivity, and high ignition temperature. The blending of FA and TC induced most of the organic components in TC to be chemically or physically adsorbed by FA, accounting for 3–13 wt% of the resultant mixtures of FA and TC (FATCs) and 11–33 wt% of the TCs. The acidic components in TC dissolved locally aggregated Ca minerals in FA, resulting in more evenly dispersed Ca on the surface of FA as an in-situ catalyst. As a result, FATCs exhibited a many-fold improvement in CO2 gasification reactivity compared to FA. And the syngas evolution rate of FATC gasification in steam-oxygen atmosphere was also remarkably elevated. In addition to the promoting effect on gasification, the combustion performance of FATCs was also greatly improved. Specifically, the ignition and burnout temperatures of FATCs were 46.5–68.5 °C and 12.4–31.7 °C lower than those of raw FA, respectively. The lower activation energy also demonstrated the higher reactivity of FATC gasification and combustion.

Advances on Understanding Coke Gasification Process with CO2: A Report from Density Functional Theory

AbstractCO2 gasification process on different active edges of a particular coke model surface has been explored computationally. It is observed that the adsorption through carbon and oxygen end of CO2 (CO‐mode) through formation of four‐ and five‐membered ring on the active sites is the favoured one. Our calculation also reveals that the strength of adsorption depends on nature and position of the active sites. The exergonic adsorption energy of CO‐mode drives the first CO release process and also makes it favoured compared to the adsorption mode where CO2 has been absorbed through its two‐oxygen end (OO‐mode). Among all the intermediates, intermediate having oxygen attached to the middle‐carbon of the coke (middle‐oxygenated coke) is found to be the most stable intermediate. The energy barrier for the second CO release also depends on the attachment sites of the oxygen on the coke surface. It is noteworthy that first principles investigations of coke gasification reactions with CO2 reported to date are found to consider different coke active sites separately on different coke model surfaces. In this context, our work is believed to be the first of its kind where complete characterization of CO2 gasification reactions has been performed considering all the active sites in a single coke model, thus providing a more coherent picture of it.

Quantifying the effect of CO2 gasification on pulverized coal char oxy-fuel combustion

Previous research has provided strong evidence that CO2 and H2O gasification reactions can provide non-negligible contributions to the consumption rates of pulverized coal (pc) char during combustion, particularly in oxy-fuel environments. Fully quantifying the contribution of these gasification reactions has proven to be difficult, due to the dearth of knowledge of gasification rates at the elevated particle temperatures associated with typical pc char combustion processes, as well as the complex interaction of oxidation and gasification reactions. Gasification reactions tend to become more important at higher char particle temperatures (because of their high activation energy) and they tend to reduce pc oxidation due to their endothermicity (i.e. cooling effect). The work reported here attempts to quantify the influence of the gasification reaction of CO2 in a rigorous manner by combining experimental measurements of the particle temperatures and consumption rates of size-classified pc char particles in tailored oxy-fuel environments with simulations from a detailed reacting porous particle model. The results demonstrate that a specific gasification reaction rate relative to the oxidation rate (within an accuracy of approximately +/- 20% of the pre-exponential value), is consistent with the experimentally measured char particle temperatures and burnout rates in oxy-fuel combustion environments. Conversely, the results also show, in agreement with past calculations, that it is extremely difficult to construct a set of kinetics that does not substantially overpredict particle temperature increase in strongly oxygen-enriched N2 environments. This latter result is believed to result from deficiencies in standard oxidation mechanisms that fail to account for falloff in char oxidation rates at high temperatures.

Insight into the relationship between CO2 gasification characteristics and char structure of biomass

Biomass gasification consists of three thermochemical stages: drying, pyrolysis, and char gasification, of which char gasification is the rate-limiting step. This study compared the char structure of biomass components (cellulose, hemicellulose, lignin, starch, and pectin) and revealed its quantitative relationship with the CO2 gasification reaction rate. Gasification experiments were performed in a self-built macro-thermogravimetric analyzer (Macro-TGA), and the char was characterized by proximate analysis, ultimate analysis, Fourier transform infrared (FTIR) spectroscopy, N2 adsorption/desorption isotherm, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The char gasification starting temperature from low to high was pectin ≈ starch < lignin < xylan. SEM revealed that the cellulose and starch chars had larger block structures. According to the FTIR results, the hydroxyl groups in the char enhanced the reactivity of char gasification. C–C/C=C was the dominant functional group in char, and O-containing groups, especially C–O, positively affected char gasification reactivity. It was found that the relationship between the gasification mass loss rate r and the char structure was r = 0.384 × surface area0.12 × ash content0.24. This study helps understand the relationship between biomass char gasification and its structure.

Migration and transformation of alkali/alkaline earth metal species during biomass and coal co-gasification: A review

Co-gasification of biomass and coal is a promising technology for clean and high-efficiency utilization of these two carbon resources. Alkali/alkaline earth metal species (AAEMs) in gasification feedstock not only are the key factors for the synergy behavior on co-gasification reactivity, but also show great relationships with the slagging, fouling and corrosion issues in practical application. Therefore, it is necessary to make a clear understanding of the migration and transformation law of AAEMs in the co-gasification process. This paper made a detailed summary of the main detection methods for AAEMs migration and transformation during co-gasification. The influencing factors of AAEMs migration and transformation in co-gasification process were systematically reviewed. Migration and transformation pathways of AAEMs during co-gasification were also proposed. Additionally, relationship between AAEMs migration and transformation and the synergy of co-gasification was deeply discussed. Finally, the research prospects were put forward based on this review.

Progress in physicochemical properties of ash/slag from co-gasification of agroforestry waste biomass and coal

Co-gasification of agroforestry waste biomass and coal realizes energy-saving, low-carbon emission, clean and efficient raw material conversion by taking advantage of their similarities and complementarities. The physicochemical properties of ash slag for raw materials are one of the key factors affecting the stable operation of co-gasification. It is the focus of co-gasification research. This paper reviews the research status of physicochemical properties of ash slag from co-gasification of agroforestry waste biomass and coal. It mainly includes the similarity and difference between agroforestry waste biomass ash and coal ash, the fusion and viscosity-temperature characteristics of mixed ash, the effect of alkali/alkaline earth metals in mixed ash on co-gasification reactivity, and sintering behavior during the slagging process. The influence mechanism of adding agroforestry waste biomass on the melting flow and sintering behavior of mixed ash is discussed. The prediction models and methods of fusion characteristics, viscosity-temperature, and slagging characteristics of mixed ash are also summarized. Finally, the future research directions of ash slag from co-gasification of agroforestry waste biomass and coal are proposed.

Effect of Ca/ Fe-based auxiliaries on anthracite char gasification under CO2 atmosphere: Synergistic catalysis

Poor reactivity of anthracite has always been a thorny problem to solve. The research on catalytic gasification of anthracite is helpful to the application of anthracite. This paper studied the gasification characteristics of demineralized anthracite char by the Ca/ Fe-based auxiliaries. The results show that both Ca/ Fe-based auxiliaries have a catalytic effect on the gasification reactivity of anthracite char, and the catalytic product becomes more evident with the increase of the additional amount. The synergistic effect of Ca-Fe composite auxiliaries is better than that of a single Ca and Fe catalyst, and the synergistic effect is most evident in the middle of the reaction. With the increase of conversion rate, the addition of Fe-based auxiliaries only reduced the activation energy of the CO2 gasification reaction but did not change the reaction process. Ca-based auxiliaries stimulus changed the reaction process to a certain extent.

Facemasks and ferrous metallurgy: improving gasification reactivity of low-volatile coals using waste COVID-19 facemasks for ironmaking application

The global pandemic response to COVID-19 has led to the generation of huge volumes of unrecyclable plastic waste from single use disposable face coverings. Rotary hearth furnaces can be used to recover Zn and Fe from non-recyclable steelmaking by-product dusts, and waste plastic material such as facemasks could be utilized as a supplementary reductant for the rotary hearth furnace (RHF), but their fibrous form makes milling and processing to appropriate sizing for RHF application extremely challenging. A scalable method of grinding facemasks to powder by melting and mixing with Welsh coal dust reported herein provides a solution to both environmental challenges. The melt-blended PPE/coal dust shows a dramatically improved CO2 gasification reactivity (Ea = 133–159 kJmol−1) when compared to the untreated coal (Ea = 183–246 kJmol−1), because of improved pore development in the coal during the pyrolysis stage of heating and the catalytic activity of the CaO based ash present in the facemask plastic. The results are promising for the application of waste facemasks in recycling steelmaking by-product dusts in rotary hearth furnaces and may also be suitable for direct injection to the blast furnace subject to further study.

In-situ catalytic gasification of sodium-rich direct coal liquefaction residue under CO2 atmosphere and kinetic analysis of gasification reaction process

Due to attractive features, such as low mineral matter content and strong reactivity, sodium-rich coals are viewed as suitable raw materials for direct coal liquefaction technology. After direct coal liquefaction process, the inherent sodium species in sodium-rich coals will be enriched in direct coal liquefaction residue. In this work, to provide potential guidance for better utilization of sodium-rich direct coal liquefaction residue, catalytic effects of the inherent sodium species on gasification reactivity of sodium-rich direct coal liquefaction residue and kinetic analysis of gasification reaction process were investigated in detail. The results show that inherent sodium species has obvious catalytic effects on gasification of sodium-rich direct coal liquefaction residue. Compared with that for demineralized direct coal liquefaction residue, the time for sodium-rich direct coal liquefaction residue to be completely gasified at 1000 °C and 1100 °C was shortened by 82% and 70%, respectively. With the increase of gasification temperature, CO2 gasification reactivity of all types of direct coal liquefaction residue was enhanced. For instance, gasification reactivity indexes (R0.5) of sodium-rich direct coal liquefaction residue are 0.06 min−1, 0.15 min−1, and 0.23 min−1 at 900 °C, 1000 °C, and 1100 °C, respectively. Kinetic analyses indicate that linear correlation coefficients obtained by homogeneous model and shrinking core model are on high levels and they are closely related with gasification temperature and residue type. According to calculation of homogeneous model and shrinking core model, activation energies of demineralized direct coal liquefaction residue are 78.60 kJ/mol and 73.73 kJ/mol, respectively. In contrast, the corresponding activation energies of sodium-rich direct coal liquefaction residue are 75.42 kJ/mol and 71.55 kJ/mol, which proves that activation energy required for gasification of direct coal liquefaction residue can be reduced by the inherent sodium species. To conclude, catalytic coal gasification may be potentially efficient to process sodium-rich direct coal liquefaction residue.

CO2 Gasification Reactivity and Syngas Production of Greek Lignite Coal and Ex-Situ Produced Chars under Non-Isothermal and Isothermal Conditions: Structure-Performance Relationships

The presented work explores the structural properties, gasification reactivity, and syngas production of Greek lignite fuel (LG) and ex-situ produced chars during CO2 gasification. Three different slow pyrolysis protocols were employed for char production involving torrefaction at 300 °C (LG300), mild-carbonization at 500 °C (LG500), and carbonization at 800 °C (LG800). Physicochemical characterization studies, including proximate and ultimate analysis, X-ray Diffraction (XRD), and Raman spectroscopy, revealed that the thermal treatment under inert atmospheres leads to chars with increased fixed carbon content and less ordered surface structures. The CO2 gasification reactivity of pristine LG and as-produced chars was examined by thermogravimetric (TG) analysis and in batch mode gasification tests under both isothermal and non-isothermal conditions. The key parameters affecting the devolatilization and gasification steps in the overall process toward CO-rich gas mixtures were thoroughly explored. The gasification performance of the examined fuels in terms of carbon conversion, instant CO production rate, and syngas generation revealed an opposite reactivity order during each stage. TG analysis demonstrated that raw lignite (LG) was more reactive during the thermal devolatilization phase at low and intermediate temperatures (da/dtmax,devol. = 0.022 min−1). By contrast, LG800 exhibited superior gasification reactivity at high temperatures (da/dtmax,gas. = 0.1 min−1). The latter is additionally corroborated by the enhanced CO formation of LG800 samples under both non-isothermal (5.2 mmol) and isothermal (28 mmol) conditions, compared to 4.1 mmol and 13.8 mmol over the LG sample, respectively. The pronounced CO2 gasification performance of LG800 was attributed to its higher fixed carbon content and disordered surface structure compared to LG, LG300, and LG500 samples.

Comprehensive investigation on the gasification reactivity of pyrolysis residue derived from Ca-rich petrochemical sludge: Roles of microstructure characteristics and calcium evolution

Pyrolysis-gasification coupling process is an effective technology that can realize the thorough reutilization and clean disposal of petrochemical sludge. However, pyrolysis residue of petrochemical sludge (PRPS) produced at different temperatures possesses obviously different structure properties, which profoundly impacts the subsequent gasification. This study reveals the effect of pyrolysis degree of PRPS on the CO2 gasification reactivity by evaluating the micromorphology, pore property, existed form of calcium mineral and carbon structural characteristics. Results demonstrate that micromorphology development of the PRPSs with diverse pyrolysis degree (PRPS prepared at 500–900 °C) has three main stages, namely, the emergence of macropores and fissures (500–600 °C), the pore development (700–800 °C), and the pore jam (900 °C). The optimal PRPS was obtained at 800 °C-pyrolysis (800-PRPS) as the maximal specific surface area and desorption pores volume were observed. In addition, Raman analysis indicated that the 800-PRPS has the best carbon activity as well. By further increasing pyrolysis temperature to 900 °C, the carbon disordering, defect, and active sites of the PRPS decreased. Moreover, results of non-isothermal PRPS-CO2 reaction indicated that the basic calcium compound carbonation, gasification, calcium carbonate decomposition regimes were involved. Compared with 800–900 PRPSs, 500–700 PRPSs were more vulnerable in the lower gasification temperature owing to the more char matrix remain. In addition, owing to the occurrence of the carbonation reaction, the calcium carbonate product layer was formed and might affect the early-age gasification.