Formaldehyde Production Research Articles

Balancing CO chemisorption with hydrogen electrochemical adsorption on Pt alloy catalyst for improving direct CO reduction to formaldehyde

Direct CO reduction to formaldehyde (CORTF) provides an alternative, energy-efficient route for production of formaldehyde, a critical chemical commodity as well as promising hydrogen carrier. However, the conventional thermal catalysis approach is challenged with slow reaction kinetics, which can be attributed to imbalanced CO and hydrogen competitive chemisorption to catalyst, with stronger CO adsorption significantly inhibiting hydrogen adsorption that suppresses their reaction towards formaldehyde generation. We report a new, innovative CORTF mechanism to promote the reaction by utilizing hydrogen underpotential deposition to balance the species coverage on catalyst surface. Our study shows that, by separately tuning Pt alloy nanoparticle catalyst composition to control CO chemical adsorption favorability and tuning hydrogen underpotential deposition potential to control hydrogen electrochemical adsorption favorability, the formaldehyde production rate with Pt alloys (866 mg/gcat/h) is 300 times higher compared to conventional thermal catalysis method (2.6 mg/gcat/h) and 50 time higher than previously reported molybdenum phosphide (MoP, 16.3 mg/gcat/h) electrocatalyst. DFT simulations show reduced energy barriers for the rate-limiting steps by means of balancing hydrogen and CO adsorption, thus supporting this new mechanism to achieve more dramatically improved CORTF kinetics. This CORTF mechanism provides a new strategy towards efficient formaldehyde production.

On the consistency of methane retrievals using the Total Carbon Column Observing Network (TCCON) and multiple spectroscopic databases

Abstract. The next and current generations of methane-retrieving satellite instruments are reliant on the Total Carbon Column Observing Network (TCCON) for validation. Understanding the biases inherent in TCCON and satellite methane retrievals is as important now as when TCCON started in 2004. In this study we highlight possible biases between different methane products by assessing the retrievals of the main methane isotopologue 12CH4. Using the TCCON GGG2014 retrieval environment, retrievals are performed using five separate spectroscopic databases from four separate TCCON sites (namely, Ascension Island, Ny-Ålesund, Darwin and Tsukuba) over the course of a year. The spectroscopic databases include those native to TCCON, GGG2014 and GGG2020; the high-resolution transmission molecular absorption database 2016 (HITRAN2016); the Gestion et Etude des Informations Spectroscopiques Atmosphériques 2020 (GEISA2020) database; and the ESA Scientific Exploitation of Operational Missions – Improved Atmospheric Spectroscopy Databases (SEOM-IAS). We assess the biases in retrieving methane using the standard TCCON windows and the methane window used by the Sentinel-5 Precursor (S5P) TROPOspheric Ozone Monitoring Instrument (TROPOMI) for each of the different spectroscopic databases. By assessing the retrieved 12CH4 values from individual windows against the standard TCCON retrievals, we find bias values of between 0.05 and 2.5 times the retrieval noise limit. These values vary depending on the window and TCCON site, with Ascension Island showing the lowest biases (typically <0.5) and Ny-Ålesund or Tsukuba showing the largest. For the spectroscopic databases, GEISA2020 shows the largest biases, often greater than 1.5 across the TCCON sites and considered windows. The TROPOMI spectral window (4190–4340 cm−1) shows the largest biases of all the spectral windows, typically >1, for all spectroscopic databases, suggesting that further improvements in spectroscopic parameters are necessary. We further assess the sensitivity of these biases to locally changing atmospheric conditions such as the solar zenith angle (SZA), water vapour and temperature. We find evidence of significant non-linear relationships between the variation in local conditions and the retrieval biases based on regression analysis. In general, each site, database and window combination indicates different degrees of sensitivity, with GEISA2020 often showing the most sensitivity for all TCCON sites. Ny-Ålesund and Tsukuba show the most sensitivity to variations in local condition, while Ascension Island indicates limited sensitivity. Finally, we investigate the biases associated with retrieving 13CH4 from each TCCON site and spectroscopic database, through the calculation of δ13C values. We find high levels of inconsistency, in some cases >100 ‰ between databases, suggesting more work is required to refine the spectroscopic parameters of 13CH4.

On the Existence and Role of Formaldehyde During Aqueous Electrochemical Reduction of Carbon Monoxide to Methanol by Cobalt Phthalocyanine.

A long-time challenge in aqueous CO2 electrochemical reduction is to catalyze the formation of products beyond carbon monoxide with selectivity. Formaldehyde is the simplest of these products and one of the most relevant due to its broad use in the industry. Paradoxically it is one of the less reported product. Such scarcity may be in part explained by difficult identification and quantification using conventional chromatography or proton nuclear magnetic resonance techniques. Likewise, indirect detection methods are usually not compatible with labelled studies for asserting product origin. Recently, the possible production of formaldehyde during electrochemical reduction of carbon monoxide to methanol at cobalt phthalocyanine molecular catalyst in basic media has been the object of contradictory reports. By applying an analytical procedure based on proton NMR along with labelled studies, we provide definitive evidence for HCHO formation. We have further identified the possible scenarios for methanol formation through formaldehyde and revealed that the formation of the intermediate and its subsequent reduction are taking place at the same single active site. These studies open a new perspective to improve selectivity toward formaldehyde formation and to develop a subsequent chemistry based on reacting it with nucleophiles.

Optimization of boron dispersion on fibrous-silica-nickel catalyst for enhanced CO2 hydrogenation to methane

There are numerous reports regarding boron-containing catalysts for hydrogen-related reactions from CO2 including dry reforming of methane and methanation. Besides enhancing the productivity, boron also improved nickel activity and stability. However, the detailed mechanistic study, particularly in explaining the starring role of boron in the enhanced reactions, is still lacking. Thus, herein we loaded boron on fibrous-silica-nickel and investigated their physicochemical properties and mechanistic route by means of in-situ FTIR for enhanced CO2 methanation. It was found that the appropriate dispersion of boron surrounds the nickel particles is an important factor to improve the adsorption of CO2 before interacting with split hydrogen atom from the nickel sides to form intermediates which are subsequently dehydrated, and then serial hydrogenation gave the final product of methane. Boron also accelerated the methanation and restricted coke formation. A hybrid approach on optimization via a face-centered central composite design and a response surface methodology showed that reaction using H2/CO2 ratio of 6, GHSV of 10,500 mL g−1 h−1, at 500 °C gave the highest percentage of CH4 of 84.3%. To indicate the error, the predicted values were compared to the experimental values, yielding an accurately minimal error ranging from 0 to 11%. As a result, the empirical models generated for CO2 hydrogenation to methane were reasonably accurate, with all actual values for the confirmation runs fitting within the 94% prediction interval.

Using Methanol as a Formaldehyde Surrogate for Sustainable Synthesis of N‐Heterocycles via Manganese‐Catalyzed Dehydrogenative Cyclization

Comprehensive SummaryThe development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock, especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals, is highly desirable. Herein, we report a novel manganese‐catalyzed dehydrogenative cyclization of methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N‐heterocycles. The in situ generated formaldehyde via catalytic methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions. The utility of this transformation is further highlighted by its successful application to the synthesis of 13C‐labeled N‐heterocycles using 13CH3OH as a readily accessible 13C‐isotope reagent.

Pollution Characteristics of Atmospheric Carbonyl Compounds in a Large City of Northern China

To better understand the pollution characteristics and formation mechanisms of atmospheric carbonyl compounds, continuous measurements of carbonyl compounds in Jinan were taken for one month at a sampling frequency of 2 h. The sources, pollution characteristics, and concentration changes of carbonyl compounds during the summers of 2018 and 2020 were compared. The total concentrations of carbonyl compounds were 10.51 ± 0.13 ppbV and 6.30 ± 1.08 ppbV in 2018 and 2020, respectively. In both years, formaldehyde, acetone, and acetaldehyde were the major carbonyls. Diurnal variations and correlation analyses showed that exhaust emissions from motor vehicles during peak traffic periods significantly contributed to the concentrations of carbonyl compounds in Jinan, with formaldehyde exhibiting net production. The ratio of formaldehyde/acetaldehyde (C1/C2) was 2.64 in 2018 and 2.03 in 2020, indicating that carbonyl compounds are jointly affected by anthropogenic sources and photochemical reactions. Master Chemical Mechanism model analyses showed that the formation of formaldehyde in Jinan was controlled by RO + O2 reactions, and formaldehyde was mainly consumed via photolysis and its reaction with the hydroxyl radical. In situ photochemistry can further promote formaldehyde production. The comparison of the reactivities of different carbonyl compounds revealed that formaldehyde, acetaldehyde, butyraldehyde, and propionaldehyde play an important role in hydroxyl radical reactions and ozone generation. Among all the measured carbonyl compounds, benzaldehyde contributed the most to secondary organic aerosols (SOAs). Overall, this study provides new insights into the formation mechanisms of carbonyl compounds as well as their pollution characteristics.

Synthesis of formaldehyde from CO2 catalyzed by the coupled photo-enzyme system

Using the reduced nicotinamide adenine dinucleotide (NADH) as coenzyme, formate dehydrogenase (FDH) and formaldehyde dehydrogenase (FADH) can catalyze the reduction of CO2 to formaldehyde. In this study, a hollow fiber membrane module was used as the enzyme-bearing reactor and gas distributor, and then coupled with a UV/TiO2 photocatalytic NADH regeneration system. First, photocatalytic CO2 reduction with varied pH value and electron donor was studied as a control. Then, CO2 reduction catalyzed by the photo-enzyme coupled system was investigated and the limiting step of the reactions was analyzed. At last, the ratio of FDH and FADH, and cofactor concentration were optimized, and the operation stability was examined as well. The results show that the optimal pH value for the production of formaldehyde by photocatalysis and photo-enzyme coupling catalysis is respectively 6.5 and 7.0 with H2O as electron donor. At pH 7.0, the initial reaction rate is 0.035 and 0.104 mmol/(L·h), and the formaldehyde production after 5 h is 0.117 and 0.393 mmol/L, proving the enzymatic reduction of CO2 is predominant in the coupled system. With EDTA as electron donor, the optimal pH value is 5.5 for the coupled system, and the formaldehyde production is much higher than that with H2O at all pH values, however, part of them might come from EDTA. For the sequence reactions, the second step is a rate-limiting step, and cofactor regeneration is vital for enzyme catalysis. The optimal loading ratio of FDH and FADH is 1:0.3, and with the addition of 1 mmol/L NAD+ or NADH, the yield of formaldehyde can reach 3.83% and 6.47% after 4 h. The photo-enzyme coupled system shows a good manipulation stability during 48 h.

Comparative analysis of turboshaft engines thermodynamic cycles calculation

A brief overview of domestic and foreign programs for calculating the thermodynamic cycle of the gas turbine engine operation is provided. The focus is on comparing GasTurb and Tyumen Motor Builders methods. Configuration files are provided for NASA Chemical Equilibrium with Applications program to calculate the thermodynamic properties of methane, air, and combustion products. The main provisions of the procedure for calculating thermal schemes of turboshaft engines are presented. Using the example of a three-shaft ship-type gas turbine engine UGT 15000, the potentials for increasing efficiency by 4-7% (abs.) and reducing CO2 emissions by 20% are shown due to the installation of an intercooler during compression of the working fluid. According to the results of comparison of GasTurb and Tyumen Motor Builders programs, the correspondence of the main parameters within the permissible measurement error is established. Based on published data on UGT 15000 (DG90), the parameters of the thermodynamic cycle were identified, including the polytropical efficiency of each node and cooling rates (ISO 2314). It has been shown that due to the isotermo-adiabatic cycle of V. V. Uvarov, already in the first approximation, without extreme parameters of the thermodynamic cycle, the characteristics of the V generation of the gas turbine engine can be implemented based on affordable and economical technologies of the II-IV generation (using equiaxed nickel superalloys, cyclone or convective-film cooling of high-pressure turbine vanes and blades). The Tyumen Motor Builders methodology program is open-source and has proven itself positively in the service-pack development for engines DG90/DN80/DU80 (III-IV generation) and the new ТМ16М2 engine construction.

Electrocatalytic production of formaldehyde with formaldehyde dehydrogenase using a viologen redox mediator

The electrocatalytic reduction of formate to formaldehyde with formaldehyde dehydrogenase using methylviologen redox mediated was developed.

Generation of formaldehyde and formaldehyde-d2 for hydroxymethylations and hydroxydeuteromethylations of difluoroenolates and difluorobenzyl carbanions.

A method for the in situ production of formaldehyde from dimethylsulfoxide, bromine, and cesium carbonate is reported for reactions with difluoroenolates and difluorobenzyl carbanions. This process also generates formaldehyde-d2 for the production of 2,2-difluoro-1,1-deuteroethanols. Mechanistic and computational studies further characterize the production of hydroxymethylated and hydroxydeuteromethylated difluorinated organic molecules.

Opposite Roles of Co-enzyme Q10 and Formaldehyde in Neurodegenerative Diseases.

Most of neurodegenerative diseases (NDD) have no cure. The common etiology of neurodegenerations is unclear. Air pollutant-gaseous formaldehyde is notoriously known to induce demyelination and cognitive impairments. Unexpectedly, an amount of formaldehyde has been detected in the brains. Multiple factors can induce the generation and accumulation of endogenous formaldehyde. Excessive formaldehyde can induce oxidative stress to generate H2O2; in turn, H2O2 promote formaldehyde production. Clinical investigations have shown that an abnormal high level of formaldehyde but low level of coenzyme Q10 (coQ10) was observed in patients with NDD. Further studies have proven that excessive formaldehyde directly inactivates coQ10, reduces the ATP generation, enhances oxidative stress, initiates inflammation storm, induces demyelination; subsequently, it results in neurodegeneration. Although the low water solubility of coQ10 limits its clinical application, nanomicellar water-soluble coQ10 exhibits positive therapeutical effects. Hence, nanopackage of coQ10 may be a promising strategy for treating NDD.

The underappreciated role of monocarbonyl-dicarbonyl interconversion in secondary organic aerosol formation during photochemical oxidation of m-xylene

Photochemical oxidation (including photolysis and OH-initiated reactions) of aromatic hydrocarbon produces carbonyls, which are involved in the formation of secondary organic aerosols (SOA). However, the mechanism of this process remains incompletely understood. Herein, the monocarbonyl-dicarbonyl interconversion and its role in SOA production were investigated via a series of photochemical oxidation experiments for m-xylene and representative carbonyls. The results showed that SOA mass concentration peaked at 113.5 ± 3.5 μg m−3 after m-xylene oxidation for 60 min and then decreased. Change in the main oxidation products from dicarbonyl (e.g., glyoxal, methylglyoxal) to monocarbonyl (e.g., formaldehyde) was responsible for this decrease. The photolysis of methylglyoxal or glyoxal produced formaldehyde, favoring SOA formation, while photopolymerization of formaldehyde to glyoxal decreased SOA production. The presence of ·OH altered the balance of photolysis interconversion, resulting in greater production of formaldehyde and SOA from glyoxal than methylglyoxal. Both photolysis and OH-initiated transformations of glyoxal to formaldehyde were suppressed by methylglyoxal, while glyoxal accelerated the reaction of ·OH with methylglyoxal to generate products which reversibly converted to glyoxal and methylglyoxal. These interconversion reactions reduced SOA production. The present study provides a new research perspective for the contribution mechanism of carbonyls in SOA formation and the findings are also helpful to efficiently evaluate the atmospheric fate of aromatic hydrocarbons.

Measurement report: Photochemical production and loss rates of formaldehyde and ozone across Europe

Abstract. Various atmospheric sources and sinks regulate the abundance of tropospheric formaldehyde (HCHO), which is an important trace gas impacting the HOx (≡ HO2 + OH) budget and the concentration of ozone (O3). In this study, we present the formation and destruction terms of ambient HCHO and O3 calculated from in situ observations of various atmospheric trace gases measured at three different sites across Europe during summertime. These include a coastal site in Cyprus, in the scope of the Cyprus Photochemistry Experiment (CYPHEX) in 2014, a mountain site in southern Germany, as part of the Hohenpeißenberg Photochemistry Experiment (HOPE) in 2012, and a forested site in Finland, where measurements were performed during the Hyytiälä United Measurements of Photochemistry and Particles (HUMPPA) campaign in 2010. We show that, at all three sites, formaldehyde production from the OH oxidation of methane (CH4), acetaldehyde (CH3CHO), isoprene (C5H8) and methanol (CH3OH) can almost completely balance the observed loss via photolysis, OH oxidation and dry deposition. Ozone chemistry is clearly controlled by nitrogen oxides (NOx ≡ NO + NO2) that include O3 production from NO2 photolysis and O3 loss via the reaction with NO. Finally, we use the HCHO budget calculations to determine whether net ozone production is limited by the availability of VOCs (volatile organic compounds; VOC-limited regime) or NOx (NOx-limited regime). At the mountain site in Germany, O3 production is VOC limited, whereas it is NOx limited at the coastal site in Cyprus. The forested site in Finland is in the transition regime.

Changes in the physicochemical composition of Auricularia auricula during growth stages and control of endogenous formaldehyde

To maintain quality and reduce endogenous formaldehyde content in the edible fungus, Auricularia auricula, the critical period of formaldehyde generation was identified and controlled. In this study, different growth stages of A. auricula were used to assess the nutritional composition (polyphenol monomers, 5′-nucleotides, organic acids and water-soluble vitamins) and related enzyme activities; the correlation between quality and endogenous formaldehyde content was also analysed. The results showed that formaldehyde was positively correlated with soluble protein and melanin levels; it was negatively correlated with the total sugar and flavonoid contents. Among the four growth stages, ripe A. auricula (RAA) had the highest endogenous formaldehyde content. The activities of γ-glutamyl transpeptidase (GGT) and l-cysteine sulphoxide lyase (C-S lyase) were highest in RAA; they promoted endogenous formaldehyde production. RAA is a critical period for interventions to reduce endogenous formaldehyde contents. Experiments to distinguish the effects of 10 exogenous substances on GGT and C-S lyase indicated that cysteine (Cys) and glutamic acid (Glu) inhibited the production of endogenous formaldehyde by 17.13% and 14.89%, respectively. This study provides a new perspective for controlling safety during the growth of edible fungi and maintaining the quality of processed products.

Measurement report: Observation-based formaldehyde production rates and their relation to OH reactivity around the Arabian Peninsula

Abstract. Formaldehyde (HCHO) is the most abundant aldehyde in the troposphere. While its background mixing ratio is mostly determined by the oxidation of methane, in many environments, especially in the boundary layer, HCHO can have a large variety of precursors, in particular biogenic and anthropogenic volatile organic compounds (VOCs) and their oxidation products. Here we present shipborne observations of HCHO, hydroxyl radical (OH) and OH reactivity (R(OH)), which were obtained during the Air Quality and Climate Change in the Arabian Basin (AQABA) campaign in summer 2017. The loss rate of HCHO was inferred from its reaction with OH, measured photolysis rates and dry deposition. In photochemical steady state, the HCHO loss is balanced by production via OH-initiated degradation of VOCs, photolysis of oxygenated VOCs (OVOCs) and the ozonolysis of alkenes. The slope αeff from a scatter plot of the HCHO production rate versus the product of OH and R(OH)eff (excluding inorganic contribution) yields the fraction of OH reactivity that contributes to HCHO production. Values of αeff varied between less than 2 % in relatively clean air over the Arabian Sea and the southern Red Sea and up to 32 % over the polluted Arabian Gulf (also known as Persian Gulf), signifying that polluted areas harbor a larger variety of HCHO precursors. The separation of R(OH)eff into individual compound classes revealed that elevated values of αeff coincided with increased contribution of alkanes and OVOCs, with the highest reactivity of all VOCs over the Arabian Gulf.

Thermodynamically controlled photo-electrochemical CO2 reduction at Cu/rGO/PVP/Nafion multi-layered dark cathode for selective production of formaldehyde and acetaldehyde

Transforming greenhouse gases such as CO2 to energy rich carbon-based chemicals is considered as one of the most efficient technologies for environmental and energy sustainability. However, CO2 is highly stable molecule and difficult to reduce due to its linear structure. The rate of reduction and the nature of fuel product depend on the kinetics and thermodynamics of involved reactions. While the overall reaction kinetics depends on the energy of activated CO2 molecule and its subsequent transition states along with reduction dynamics. Here we demonstrate that by activation of thermodynamically stable CO2 molecule through complexation or coordination with suitable activator such as N-heterocyclic polymers (e.g., poly(4-vinyl)pyridine, PVP), both the kinetics and thermodynamics of photoelectrochemical CO2 reduction reaction can be controlled by proper choice of electrode materials and bias potential. We present a solar light driven photoelectrochemical process for producing formaldehyde and acetaldehyde selectively on multi-layered Cu/rGO/PVP/Nafion hybrid cathode.

Highly Stable Apatite Supported Molybdenum Oxide Catalysts for Selective Oxidation of Methanol to Formaldehyde: Structure, Activity and Stability

AbstractMolybdenum oxide (5 to 20 wt.%) supported on calcium or strontium hydroxyapatite were investigated as catalysts for selective oxidation of methanol to formaldehyde. These catalysts were both active and selective, with a maximum yield achieved at 95 % conversion and 96 % selectivity. The main byproducts were CO (3.2 %) and dimethyl ether (DME, 0.7 %). The catalytic performance of the catalysts was measured for up to 600 h at 350 °C. Compared to an industrial iron molybdate catalyst, the hydroxyapatite based catalysts deactivated slower. The active species were found to be a surface layer of MoOx on the hydroxyapatite support, while excess molybdenum formed crystalline (Ca/Sr)MoO4, acting as a reservoir replenishing surface MoOx lost by volatilization with methanol. The excess molybdenum in the form of (Ca/Sr)MoO4 was found to volatilize significantly slower than the excess MoO3 in iron molybdate catalysts. The combination of high activity and selectivity with low rate of Mo volatilization makes this class of catalysts interesting for industrial production of formaldehyde.

Enhanced CO2 Conversion into Ethanol by Permanently Polarized Hydroxyapatite through C−C Coupling

AbstractHydroxyapatite (HAp) is a naturally occurring mineral form of calcium apatite of biomedical importance due to its similarity with human hard tissues in morphology and composition. Upon polarization at high temperature, applying 3 kV/cm at 1000 °C, the resulting polarized HAp (p‐HAp) exhibits enhanced catalytic behavior due charge accumulation at the interface. More specifically, p‐HAp was found to catalyse the conversion of mixtures of CO2(g) and CH4(g) into low carbon organic molecules and into amino acids when N2(g) was added to the mixture. In this work, we report how p‐HAp facilitates the conversion of CO2(g) mainly in ethanol by means of forming C−C coupled bonds on its activated surface. After evaluation of a wide range of experimental conditions, we evidence the production of formic acid, methanol and formaldehyde (C1 products); ethanol and acetic acid (C2 products); and acetone (C3 product) from CO2(g) using moderate reaction conditions. Moreover, optimization of the reaction parameters led to a significant increase towards ethanol.

Fischer–Tropsch Synthesis: Effect of the Promoter’s Ionic Charge and Valence Level Energy on Activity

In this contribution, we examine the effect of the promoter´s ionic charge and valence orbital energy on the catalytic activity of Fe-based catalysts, based on in situ synchrotron X-ray powder diffraction (SXRPD), temperature-programmed-based techniques (TPR, TPD, CO-TP carburization), and Fischer–Tropsch synthesis catalytic testing studies. We compared the promoting effects of K (a known promoter for longer-chained products) with Ba, which has a similar ionic radius but has double the ionic charge. Despite being partially “buried” in a crystalline BaCO3 phase, the carburization of the Ba-promoted catalyst was more effective than that of K; this was primarily due to its higher (2+) ionic charge. With Ba2+, higher selectivity to methane and lighter products were obtained compared to the K-promoted catalysts; this is likely due to Ba´s lesser capability of suppressing H adsorption on the catalyst surface. An explanation is provided in terms of a more limited mixing between electron-filled Ba2+ 5p and partially filled Fe 3d orbitals, which are expected to be important for the chemical promotion, as they are further apart in energy compared to the K+ 3p and Fe 3d orbitals.

One step methane production based on catalytic pressurized calcium looping gasification with in-situ CO2 capture and self-sustained heat supply

Catalytic steam hydrogasification of coal is a direct method for methane production. Calcium looping concept is usually used in coal gasification process for in-situ carbon dioxide removal and heat supply. In this paper, a new process combining catalytic steam hydrogasification and calcium looping was proposed and investigated using a self designed instantaneously feeding reactor under high-temperature and pressurized conditions. The effects of operation conditions (including hydrogen concentration with a range of 0–50 vol%, gasification pressure with a range of 0.1–3.5 MPa, gasification temperature with a range of 700–800 °C, and gasification-calcination cycle number up to six) on the performance of the new process have been studied. The results show that: (i) increasing H2 concentration is beneficial to methane products; (ii) high temperature and low pressure are not conducive to methane production and carbon dioxide capture as well as the self-sustained heat supply in gasifier; (iii) the methane content and carbon conversion can be maintained at 30–40 vol% and 75–80% for the durability tests. According to the performance of gas products, 750 °C 3.5 MPa and Ca/C = 0.5 are suggested for the new process. In addition, the gasification reactivity can be affected by the Ca–K-Char interaction as indicated by the XRD, FT-IR and SEM-EDX analysis.