High Hydrogen Content Research Articles

Novel BECCS implementation integrating chemical looping combustion with oxygen uncoupling and a kraft pulp mill cogeneration plant

Bioenergy with CO2 capture and storage (BECCS) is a promising negative emission technology (NET). When using sustainably produced biomass as fuel, BECCS allows the production of power and heat with negative CO2 emissions. The main technical challenges hindering the deployment of BECCS technologies include energy penalties associated with the capture process. This work evaluates the performance of an advanced CO2 capture technology, chemical looping with oxygen uncoupling (CLOU), replacing a conventional fluidized bed boiler in the power boiler role in a large, modern integrated pulp and paper mill. Results from a MATLAB/Simulink reactor model were incorporated in a plant and integration model developed in a commercial process simulation software to quantify the performance of the CLOU-integrated cogeneration plant. The results show that in this specific application, the typically already low efficiency penalty of CLOU-based carbon capture and storage (CCS) systems could be eliminated entirely, and actually even a very small efficiency gain could be obtained. The highly efficient operation is possible due to the high moisture and hydrogen contents of the biomass and the separation of combustion products and excess air streams in the CLOU process; this provides an opportunity to recover a significant amount of heat by flue gas condensation at a higher temperature level than what is possible in a conventional boiler. Together with abundant low-temperature heat sinks available at the pulp and paper application allows freeing a considerable amount of low-pressure steam for expansion in the condensing turbine. The resulting increase in gross generator output proved enough to not only match, but very slightly exceed the approximately 18 MW parasitic load introduced by the CLOU system in comparison to the conventional boiler.

Suppression of hydrogen embrittlement of gear steel 20CrMnTiH with pulsed electric current

When steel is smelted and used, hydrogen penetration will lead to hydrogen embrittlement, reduce the service life of materials, and even cause safety accidents. Various defects in steel can trap hydrogen atoms as hydrogen traps, resulting in high hydrogen content in materials. In this study, 20CrMnTiH gear steel billets with high hydrogen content were treated by electric pulse. It was found that the elongation and tensile strength of the samples treated by electric pulse were improved, which is attributed to the reduction of diffusible hydrogen content in the sample. Meanwhile, as an irreversible hydrogen trap, FeO's reduction makes it easier for hydrogen atoms to diffuse and escape under the electric field. Pulse current not only promotes the diffusion of hydrogen atoms, but also eliminates some hydrogen traps. The hydrogen control method under pulse current provides another alternative for solid state dehydrogenation and repair of hydrogen embrittlement fracture.

Mass Spectrometric study of graphene-oxide irradiated in vacuum by Nd:YAG laser

During the laser ablation of a graphene oxide target in the vacuum with a 1064 nm ns laser at about 60 J/cm2 fluence, the ablation dynamics and molecular emission have been investigated using a quadrupole mass spectrometer (QMS), time-of-flight measures of the emitted ions and dedicated spectroscopies. The plasma characterization has been obtained giving providing the involved ion species and charge states, and the average temperature and density. Increasing the laser fluence the ablation yield, the plasma density and temperature, the velocity of the emitted particles and the emitted mass yields increase. Due to the laser heating a graphene oxide reduction is also observed. The oxygen is emitted as elemental and as part of different functional groups. A strong dehydration and dehydrogenation occur due to the laser pulse energy deposition, testifying the high content of water and hydrogen possessed by graphene oxide.

Destabilization of the LiBH4–NaBH4 Eutectic Mixture through Pore Confinement for Hydrogen Storage

Both LiBH4 and NaBH4 are well known for having high hydrogen contents, but also high decomposition temperatures and slow hydrogen absorption–desorption kinetics, preventing their use for hydrogen storage applications. The low melting temperature (219 °C) of their eutectic mixture 0.71 LiBH4–0.29 NaBH4 allowed the synthesis of a new composite material through the melt infiltration of the hydrides into the ~5 nm diameter pores of a CMK-3 type carbon. A composite of 0.71 LiBH4–0.29 NaBH4 and non-porous graphitic carbon discs was also prepared by similar methods for comparison. Both composites showed improved kinetics and a partial reversibility of the dehydrogenation/rehydrogenation reactions. However, the best results were observed for the CMK-3 nanoconfined hydrides; a consistent uptake of about 3.5 wt.% H2 was recorded after five hydrogenation/dehydrogenation cycles for an otherwise non-reversible system. The improved hydrogen release kinetics are attributed to carbon–hydride surface interactions rather than nanoconfinement, while enhanced heat transfer due to the carbon support may also play a role. Likewise, the carbon–hydride contact proved beneficial in terms of reversibility, without, however, ruling out the potential positive effect of pore confinement.

Impacts of wind conditions on hydrogen leakage during refilling hydrogen-powered vehicles

Although hydrogen leakage at hydrogen refueling stations has been a concern, less efforts have been devoted to hydrogen leakage during the refueling of hydrogen-powered vehicles. In this study, hydrogen leakage and dilution from the hydrogen dispenser during the refueling of hydrogen-powered vehicles were numerically investigated under different wind configurations. The shape, size, and distribution of flammable gas clouds (FGC) during the leakage and dilution processes were analyzed. The results showed that the presence of hydrogen-powered vehicles resulted in irregular FGC shapes. Greater wind speeds (vwv) were associated with longer FGC propagation distances. At vwv = 2 m·s−1 and 10 m·s−1, the FGC lengths at the end of the leakage were 7.9 m and 20.4 m, respectively. Under downwind conditions, higher wind speeds corresponded to lower FGC heights. The FGC height was larger under upwind conditions and was slightly affected by the magnitude of the wind speed. In the dilution process, the existence of a region with a high hydrogen concentration led to the FGC volume first increasing and then gradually decreasing. Wind promoted the mixing of hydrogen and air, accelerated FGC dilution, inhibited hydrogen uplifting, and augmented the horizontal movement of the FGC. At higher wind speeds, the low-altitude FGC movements could induce potential safety hazards.

Ti3C2OH MXene supported NiPtP nanoparticles with low noble metal content as hydrazine dehydrogenation catalysts

BackgroundHydrazine hydrate is widely used in hydrogen production due to its high hydrogen content and good room temperature stability. However, the decomposition pathway of hydrazine hydrate is related to the type of catalyst, therefore, it is necessary to develop efficient and good selective catalysts. Methodswe have developed a method for preparing NiPtP NPs on MXene using NaH2PO2 as a non-metallic phosphorus source by a one-pot reduction method. The structure and chemical composition of catalysts were studied by Scanning electron microscope (SEM), Energy dispersive spectroscopy (EDS), Transmission electron microscope (TEM), X-ray powder diffractometer (XRD), Inductively coupled plasma-atomic emission spectrometry (ICP-AES), and X-ray photoelectron spectroscopy (XPS). Significant findingsThe results show that the P doping significantly improved the catalytic hydrogen production activity of the Ni0.74Pt0.2P0.06@MXene catalysts in alkaline hydrazine hydrate solutions. The Ni0.74Pt0.2P0.06@MXene catalyst had good catalytic activity for the catalytic production of hydrogen from alkaline hydrazine hydrate solutions under mild conditions, with 100% selectivity for H2 and a TOF value of 794 h−1 at 323 K. This facile synthetic method for the preparation of transition metal phosphides, combined with the high catalytic activity, high hydrogen selectivity and low cost of Ni0.74Pt0.2P0.06@MXene catalysts, may facilitate the practical application of MXene in the field of chemical hydrogen storage, and further fill the gap in the application of transition metal phosphide materials in the field of hydrogen production.

Natural Hydrogen in South Australia

Natural hydrogen exploration become possible in South Australia on 11 February 2021 via regulatory changes to include hydrogen as a ‘regulated substance’ under the Petroleum and Geothermal Energy Act 2000. South Australia has attracted interest from explorers because it is the only Australian jurisdiction currently with a licensing regime in place and favourable geology which could potentially generate natural hydrogen. In addition, online historical records revealed high hydrogen concentrations in gas samples from old wells.

Study of the influence of current density and displacement rate on hydrogen embrittlement using small punch tests

Susceptibility to hydrogen embrittlement was studied on quenched and tempered 42CrMo steel with Small Punch Tests (SPT) using different punch displacement rates. Hydrogen was cathodically charged using an electrolyte composed of 1 M H2SO4 with 0.25 g/l As2O3, and two different cathodic current densities (0.50 and 1.00 mA/cm2). The results were analysed using different embrittlement indices: related to the energy consumed at maximum load, to the equivalent biaxial deformation at failure location and to the failed diameter. Failure location is directly related to punch displacement and, consequently, to embrittlement.All embrittlement indices increase as the punch displacement rate decreases (longer time for hydrogen diffusion) and as the cathodic current density increases (higher hydrogen concentration in equilibrium with the hydrogenated medium). On the other hand, the use of a pre-charging time before the start of the in-situ hydrogen charged test produces no change in the results, as most hydrogen enters the sample due to the high plastic deformation induced on its surface in the course of the mechanical test.

Research on the hydrogen injection strategy of a turbulent jet ignition (TJI) rotary engine fueled with natural gas/hydrogen blends

Natural gas/hydrogen blends (NGHB) fuel is considered as one of the ideal alternative fuels for the rotary engine (RE), which can effectively reduce the carbon emissions of RE. Additionally, applying turbulent jet ignition (TJI) mode to RE can significantly increase the combustion rate. The purpose of this study is to numerically investigate the influence of hydrogen injection position (HIP) and hydrogen injection timing (HIT) on the in-cylinder mixture formation, flame propagation and NOx emission of a TJI hydrogen direct injection plus natural gas port injection RE. Therefore, in this paper, a test bench and a 3D dynamic simulation model of the turbulent jet ignition rotary engine (TJI-RE) fueled with NGHB were respectively established. Moreover, the reliability of the 3D simulation model was verified by experimental data. Furthermore, based on the established 3D model, the fuel distribution and flame propagation in the cylinder under different HIPs and HITs were calculated. The results indicated that the HIP and HIT could change the hydrogen distribution by altering the impact position, impact angle, and the strength of vortexes in the cylinder. To improve the flame propagation speed, more hydrogen should be distributed in the pre-chamber. Additionally, a higher concentration of hydrogen in the cylinder should be maintained above the jet orifice. This was not only conducive to the rapid formation of the initial fire core in the pre-chamber, but also significantly improved the combustion rate of the in-cylinder mixture. Compared with other hydrogen injection strategies, the hydrogen injection strategy by using the HIP at the middle of the cylinder block and the HIT of 190oCA(BTDC) could obtained the highest peak value of in-cylinder pressure and the highest NOx emission.

Kinetic Analysis of Pyrolysis Reaction of Hydrogen-Containing Low Rank Coals Based on Thermogravimetric Method

Based on the combined technology of thermogravimetric analysis-mass spectrometry (TG-MS), the non isothermal kinetic of two low rank coals with high hydrogen content and the release characteristics of H2 in volatiles were explored. The effect of coal species and coal particle size on pyrolysis was studied. The CR (Coats-Redfern) method and the DAEM (Distributed activation energy model) method were used to construct the pyrolysis kinetic model by dividing temperature stages, and the results showed that the mechanisms of pyrolysis process of lower rank coals were mainly 3-D diffusion (G-B) and Growth of nucleation (Avrami-Erofeev, n = 1/3). The use of the DAEM method made up for the shortcomings of the CR method in calculating the activation energy, and the analysis of coal pyrolysis kinetics was more comprehensive. The higher the volatile content the coal contained, the lower activation energy the pyrolysis process would require. The larger the particle size of the coal was, the higher activation energy the pyrolysis process would need. The release law of H2 in low rank coal during the pyrolysis process was analyzed by mass spectrometry, and results were presented: the first peak occurs at 500 °C and the second at 750 °C, which was mainly generated by the condensation and dehydrogenation reactions of aromatic compounds.

Efficient PFAS prioritization in non-target HRMS data: systematic evaluation of the novel MD/C-m/C approach

Non-target screening (NTS) based on high-resolution mass spectrometry (HRMS) is necessary to comprehensively characterize per- and polyfluoroalkyl substances (PFAS) in environmental, biological, and technical samples due to the very limited availability of authentic PFAS reference standards. Since in trace analysis, MS/MS information is not always achievable and only selected PFAS are present in homologous series, further techniques to prioritize measured HRMS data (features) according to their likelihood of being PFAS are highly desired due to the importance of efficient data reduction during NTS. Kaufmann et al. (J AOAC Int, 2022) presented a very promising approach to separate selected PFAS from sample matrix features by plotting the mass defect (MD) normalized to the number of carbons (MD/C) vs. mass normalized to the number of C (m/C). We systematically evaluated the advantages and limitations of this approach by using ~ 490,000 chemical formulas of organic chemicals (~ 210,000 PFAS, ~ 160,000 organic contaminants, and 125,000 natural organic matter compounds) and calculating how efficiently, and especially which, PFAS can be prioritized. While PFAS with high fluorine content (approximately: F/C > 0.8, H/F < 0.8, mass percent of fluorine > 55%) can be separated well, partially fluorinated PFAS with a high hydrogen content are more difficult to prioritize, which we discuss for selected PFAS. In the MD/C-m/C approach, even compounds with highly positive MDs above 0.5 Da and hence incorrectly assigned to negative MDs can still be separated from true negative mass defect features by the normalized mass (m/C). Furthermore, based on the position in the MD/C-m/C plot, we propose the estimation of the fluorine fraction in molecules for selected PFAS classes. The promising MD/C-m/C approach can be widely used in PFAS research and routine analysis. The concept is also applicable to other compound classes like iodinated compounds.Graphical

Mast Cells in Regeneration of the Skin in Burn Wound with Special Emphasis on Molecular Hydrogen Effect.

The mechanisms of regeneration for the fibrous component of the connective tissue of the dermis are still insufficiently studied. The aim of this study was to evaluate the effectiveness of the use of molecular hydrogen on the local therapy of a II degree burn wound with the intensification of collagen fibrillogenesis in the skin. We analyzed the involvement of mast cells (MCs) in the regeneration of the collagen fibers of the connective tissue using water with a high content of molecular hydrogen and in a therapeutic ointment for the cell wounds. Thermal burns led to an increase in the skin MC population, accompanied by a systemic rearrangement of the extracellular matrix. The use of molecular hydrogen for the treatment of burn wounds stimulated the regeneration processes by activating the formation of the fibrous component of the dermis, accelerating wound healing. Thus, the intensification of collagen fibrillogenesis was comparable to the effects of a therapeutic ointment. The remodeling of the extracellular matrix correlated with a decrease in the area of damaged skin. Skin regeneration induced by the activation of the secretory activity of MCs may be one of the possible points of implementation of the biological effects of molecular hydrogen in the treatment of burn wounds. Thus, the positive effects of molecular hydrogen on skin repair can be used in clinical practice to increase the effectiveness of therapy after thermal exposure.

Experimental Evaluation of Continuous In-Situ Biomethanation of CO2 in Anaerobic Digesters Fed on Sewage Sludge and Food Waste and the Influence of Hydrogen Gas–Liquid Mass Transfer

In-situ biomethanation combines conventional biogas production from the anaerobic digestion (AD) of organic matter with the addition of hydrogen to produce a higher quality biomethane gas. However, challenges surrounding its performance and control could hinder its uptake. To investigate this, an automated rig was designed and operated to study in-situ biomethanation with sewage sludge (SS) and food waste (FW) feedstocks. The effects that were experimentally investigated included the biogas recirculation rate, stirring intensity, and organic loading rate (OLR). All the results highlighted the rate-limiting effect of H2 gas–liquid mass transfer (measured kLa in the range of 43–82 day−1), which was implied by a lack of evidence of hydrogen-induced biological inhibition and a high average equilibrium hydrogen content in the biogas (a volume of 7–37%). At an OLR of 2 g VS L−1day−1, increasing biogas recirculation and mechanical stirring rates improved the methane evolution rate up to 0.17 and 0.23 L L−1day−1 and the H2 conversion up to 80 and 66% for sewage sludge and food waste, respectively. A lower OLR of 1 g VS L−1day−1 allowed for increased hydrogen conversion but at a lower level of methane productivity. A process model, validated on experimental data, predicted that improving the kLa to at least 240 day−1 would be required for in-situ biomethanation at OLRs common in AD systems in order to achieve a drop-in quality in terms of the biogas, with further downstream treatment required for certain applications.

Hydrogen Production by N-Heterocycle Dehydrogenation over Pd Supported on Aerogel-Prepared Mg-Al Oxides

Tetradecahydrophenazine (14HP) is a nitrogen-containing heterocycle compound with a high content of hydrogen that can be released during its dehydrogenation to phenazine (P). The high stability of the 14HP/P pair and relatively low dehydrogenation temperature make 14HP a promising organic hydrogen carrier. This manuscript is devoted to the investigation of hydrogen production by 14HP dehydrogenation over Pd supported on a series of magnesium-aluminum oxides prepared by the aerogel method. This technique made it possible to synthesize catalyst supports characterized by a high surface area and high concentration of surface active sites where active transition metals could be stabilized in a finely dispersed state. The synthesized aerogels had high specific surface areas and pore volumes. A surface area as high as 600 m2/g after calcination at 500 °C was observed for the mixed aerogel with an Mg:Al ratio of 1:4. An increase in the concentration of acidic electron-acceptor sites determined by EPR on the surface of the mixed magnesium-aluminum oxide supports with a high surface area prepared by the aerogel method was found to result in higher hydrogen production due to the faster dehydrogenation of sterically hindered nitrogen-containing tetradecahydrophenazine heterocycles.

Hydrogen-assisted intergranular fatigue crack initiation in metals: Role of grain boundaries and triple junctions

In this work, small-scale, low-cycle fatigue experiments on hydrogen charged nickel specimens are performed that highlight particular grain boundaries (GBs) and triple junctions as potential intergranular crack initiation sites. To understand the micromechanics and underlying physics, a dislocation density-based crystal plasticity model coupled with slip-rate based hydrogen transport model is developed. A fatigue indicator parameter (FIP) is also developed that models the crack initiation process by considering the contributions of accumulated plastic slip, GB normal stress, and local hydrogen concentration. Depending on the diffusivity, hydrogen binding energy, and misorientation, GBs are categorized as ‘special’ or ‘random’, and their role on hydrogen distribution is analysed using a model microstructure. Special GBs are ones with low diffusivity and high hydrogen binding energy whereas the random GBs have high diffusivity but low hydrogen binding energy. Complying with the experimental observations, the evolution of FIP with load cycles suggests certain triple junction configurations in the microstructure involving in the crack initiation process. For the case of uniform initial hydrogen concentration, special GBs are found to retain more hydrogen with load cycles primarily due to their low hydrogen diffusivity whereas the random GBs diffuse hydrogen out quickly to the bulk. The high hydrogen concentration and favourable stress state in the form of high hydrostatic stress spots generally found at triple junction of special/random GBs fulfil the necessary condition leading to an intergranular crack initiation.

Regulating Competitive Adsorption on Pt Nanoparticles by Introducing Pb to Expedite Hydrogen Production via Ammonia Oxidation

Ammonia with a high hydrogen content is an ideal hydrogen carrier due to its mature storage and transport system. Ammonia electrooxidation is one of the most promising technologies for green and economic H2 production. However, ammonia oxidation reaction (AOR) is limited to a narrow potential window due to the slow kinetics and the competitive adsorption between the reactant and Had/OHad on active sites. Herein, an ultra-small PtPb alloy nanocatalyst is synthesized for AOR by the facile one-step solvothermal method. Experimental results demonstrate that the electronic structure of Pt is regulated by the introduction of Pb, inhibiting the competitive adsorption on Pt sites. Therefore, it exhibits improved AOR activity with a peak current density of 191.2 mA mg–1Pt at 10 mV s–1, which is 1.97 times that of Pt/C. The good performance is attributed to the high hydrogen evolution overpotential property of Pb and the strong p–d electron interaction of PtPb, which effectively modulates the adsorption/desorption of intermediates at the Pt site. Hence, this work proposes a simple and effective strategy for designing efficient AOR catalysts, promoting the development of H2 production by AOR.

Self-Terminating Surface Reconstruction Induced by High-Index Facets of Delafossite for Accelerating Ammonia Oxidation Reaction Involving Lattice Oxygen.

Ammonia (NH3 ) is a promising hydrogen (H2 ) carrier for future carbon-free energy systems, due to its high hydrogen content and easiness to be liquefied. Inexpensive and efficient catalysts for ammonia electro-oxidation reaction (AOR) are desired in whole ammonia-based energy systems. In this work, ultrasmall delafossite (CuFeO2 ) polyhedrons with exposed high-index facets are prepared by a one-step NH3 -assisted hydrothermal method, serving as AOR pre-catalysts. The high-index CuFeO2 facet is revealed to facilitate surface reconstruction into active Cu-doped FeOOH nanolayers during AOR processes in ammonia alkaline solutions, which is driven by the favorable Cu leaching and terminates as the 2p levels of internal lattice oxygen change. The reconstructed heterostructures of CuFeO2 and Cu-doped FeOOH effectively activate the dehydrogenation steps of NH3 and exhibit a potential improvement of 260mV for electrocatalytic AOR at 10mA cm-2 compared to the pre-restructured phase. Further, density functional theory (DFT) calculations confirm that a lower energy barrier of the rate-determining step (*NH3 to *NH2 ) is presented on high-index CuFeO2 facets covered with Cu-doped FeOOH nanolayers. Innovatively, lattice oxygen atoms in Fe-based oxides and oxyhydroxide are involved in the dehydrogenation steps of AOR as a proton acceptor, broadening the horizons for rational designs of AOR catalysts.

Oxidative catalytic steam gasification of sugarcane bagasse for hydrogen rich syngas production

Reactive Flash Volatilization (RFV) is an emerging thermochemical method to produce tar free hydrogen rich syngas from waste biomass at relatively lower temperature (<900 °C) in a single stage catalytic reactor within a millisecond residence time. Here, we show catalytic RFV of bagasse using Ru, Rh, Pd, or Re promoted Ni/Al2O3 catalysts under steam rich and oxygen deficient environment. The optimum reaction conditions were found to be 800 °C, steam to carbon ratio = 1.7 and carbon to oxygen ratio = 0.6. Rh–Ni/Al2O3 performed the best, resulting in highest hydrogen concentration in the synthesis gas at 54.8%, with a corresponding yield of 106.4 g-H2/kg bagasse. A carbon conversion efficiency of 99.96% was achieved using Rh–Ni, followed by Ru–Ni, Pd–Ni, Re–Ni and mono metallic Ni catalyst in that order. Alkali and Alkaline Earth Metal species present in the bagasse ash and char, that deposited on the catalyst, was found to enhance its activity and stability. The hydrogen yield from bagasse was higher than previously reported woody biomass and comparable to the microalgae.

A novel strategy to prevent hydrogen charging via spontaneously molten-slag-covering droplet transfer mode in underwater wet FCAW

Underwater wet welding is widely used in offshore platform maintenance, oil pipeline repair and wreck salvage operations. A high diffusible hydrogen content is recognized as one of the critical reasons behind the reduction in the reliability of underwater wet welded joints. In this study, the entry route of hydrogen during underwater wet flux-cored arc welding of 304 stainless steel at a depth of 0.5 m was first confirmed experimentally using an in-situ X-ray imaging system. The hydrogen charging was deemed to dominantly occur when pendant droplets were formed due to the extremely high temperature of molten metal and the absence of slag coverage. This resulted in 13.51 mL/100 g of diffusible hydrogen remaining in the droplet and 9.42 mL/100 g in the deposited metal. To prevent hydrogen charging, an unprecedented molten-slag-covering droplet transfer mode was developed by reducing the CaF2 content and maintaining the CaF2/TiO2 to an appropriate ratio in the flux, through which the molten slag spontaneously covered the droplet, electric arc and molten pool completely during the entire welding process and the entry of hydrogen was successfully blocked and the diffusible hydrogen content was reduced to the same level as that achieved via onshore welding (3.26 mL/100 g).

Feedstock flexible numerical analysis of sewage sludge gasification

Sewage sludge properties vary with the origin and treatment method of the wastewater. When converting the sewage sludge thermally for material and energy recovery, these properties affect the composition of the products and the efficiency of the process. Rotary kiln gasifiers can handle these variations in the raw materials. For further development, process integration, optimization of the process, upscaling, and industrial application, it is helpful to understand and describe the impact of the sewage sludge properties on operating parameters and product quality. This work analyses the impact of sewage sludge properties numerically using detailed chemistry and the surrogate approach. Sewage sludge is described using woody biomass components, sugars, lipids, proteins, inorganic species, moisture, and ash. The stochastic reactor model (SRM) is used to model the gasification process. In contrast to ideal reactors, stochastic reactors allow for resolving inhomogeneity. Hence, the predicted gas composition results from local temperature and available oxygen. For the analysis, temperature, airflow rate, and fuel properties, i.e., the amount and composition of volatiles, including fuel-bonded nitrogen and sulfur, and the moisture level are varied. Their results are analysed regarding the produced gas composition, emission precursor formation, and cold gas efficiency of the process. The highest efficiencies are found for temperatures of 1223 K and rich conditions. High concentrations of methane and hydrogen accompany this maximum. However, the producer gas’s highest heating value is found at low temperatures thanks to the presence of small hydrocarbons. Furthermore, a high volatile amount and a dry feedstock favour methane and carbon monoxide formation. The hydrogen concentration is found to be sensitive to the moisture content and is the highest at 30%. The cold gas efficiency is predicted to depend strongly on the feedstock and varies for the same operating conditions up to 60%. With increasing fuel-bonded nitrogen and sulfur content, the concentrations of NO and SO2 formation and their precursors increase, respectively. The released ammonia leads to significantly reducing emitted NO through the ThermalDeNOx mechanism. Overall, the generated maps provide a detailed insight in species formation and allows for the prediction of process parameters sensitive to the sewage sludge properties.