Effect Of Catalyst Addition Research Articles

Comparison of Random Forest and Support Vector Regression Models in Predicting Hydrogen Production Process from Biomass

The need for energy in the world is increasing day by day and various energy production methods are used to meet this need. Production of hydrogen from biomass is one of these methods. Hydrogen production from biomass is a promising process to produce hydrogen and energy which has advantages such as the ability to use sustainable energy sources like biomass and solid waste, being carbon neutral, and increasing energy independence thanks to the variation of resources and the availability of local resources. The catalysts used in this process which can be conducted in three separate ways, affect hydrogen and energy production positively or negatively. One of the most important steps in effectively acquiring the ideal amount of product is predicting the outcomes of this procedure. This article compares a support vector regression (SVR) and random forest (RF) model to predict how various inputs used to produce hydrogen from biomass will affect hydrogen output. Additionally, the effect of catalyst addition on hydrogen yield in biomass processes was examined. In this context, 57 experimental studies from the literature were selected as a data set. From this data, 90% was selected for training and 10% for testing. The outputs were evaluated according to parameters such as R2, RMSE and MSE. The results show that RF and SVR models can significantly predict catalyst activity and hydrogen production.

Interface modulation of AgBiO3 via BiOCl in situ growth: Simultaneously boosting O* and OVs production

Photocatalytic activity of the composite photocatalyst AgBiO3/BiOCl was examined after the interface of AgBiO3 was modified by growing BiOCl in situ and building heterojunction towards increasing reactive oxygen species (O*) and oxygen vacancy (OVs) production. The degradation of rhodamine B (RhB) revealed that the photocatalytic performance of the heterojunction structure of AgBiO3/BiOCl-x (x=0.05, 0.2, 2, 5) was significantly improved over that of AgBiO3 monomer, with the degradation effect of AgBiO3/BiOCl-2 reaching 99.6 % within 60 minutes and no significant decrease in performance after reuse (93 % degradation after four cycles). Similar experiments also used another contaminant, tetracycline hydrochloride (TC-HCl). Within 60 minutes, under visible light irradiation, the degradation rate of TC was 89.1 % and the degradation rate was 0.0367 min−1. The effects of catalyst addition, varied starting concentrations, and pH on RhB degradation were also studied. Furthermore, the free radical scavenging studies and chemical characterizations revealed that the principal reactive radicals functioning in the reaction system were h+, 1O2 and ‧O2-. Based on the findings, a potential catalytic mechanism for the synergistic degradation of RhB via photo-driven and chemical oxidation of AgBiO3/BiOCl heterostructures was postulated.

A heterogeneously activated peroxymonosulfate with a Co and Cu codoped bimetallic metal-organic framework efficiently degrades tetracycline in water

In the study presented in this paper, a cobalt and copper codoped bimetallic metal-organic framework (CoCu–MOF) was synthesized by a solvothermal method. The CoCu–MOF was then utilized to activate peroxymonosulfate (PMS) to degrade the tetracycline (TC) present in water. When the concentration of organic pollutants was 20 mg/L, the degradation efficiency of TC by the Co1Cu1–MOF/PMS system reached 98.17 % within 30 min, which was better than that of the PMS and Cu-MOF/PMS systems alone. The effects of catalyst addition, PMS usage, initial pH, temperature, coexisting ions and initial TC concentration on the degradation of TC by Co1Cu1–MOF were investigated. The sulfate radical (SO4•−), hydroxyl radical (•OH), superoxide radical (O2•−), and nonradical singlet oxygen (1O2) were identified as the primary reactive species through quenching experiments and electron paramagnetic resonance (EPR) analyses. Moreover, linear sweep voltammetry (LSV) analysis was used to determine the occurrence of an electron transfer-mediated nonradical pathway in the reaction system in addition to 1O2. The concentrations of the TC intermediates were determined using liquid chromatography‒mass spectrometry (LC‒MS), and potential degradation processes were proposed. This study showed that CoCu–MOF is a heterogeneous catalyst that activates PMS for efficient TC degradation.

Catalytic wet torrefaction of lignocellulosic biomass: An overview with emphasis on fuel application

Wet torrefaction (WT), also named hydrothermal carbonisation (HTC), has been regarded as one of the highly studied thermochemical process pathways for biomass-to-solid fuel conversion in the last decade (2012–2021). Catalysts have been added in the WT or HTC of lignocellulosic biomass for various applications (i.e. solid fuel synthesis, carbon material synthesis, pre-treatment, sugar production, ash content removal, and the study of reaction kinetics). Regardless, there is no review on the addition of catalysts in WT to produce hydrochar as fuel, specifically on the role of catalysts in the formation of ‘secondary deposits’, which refers to deposits that have been observed on the hydrochar. This review discusses the fundamentals of WT and how the lignocellulosic biomass components in various biomass, operating process parameters, and catalysts affect the fuel properties of the hydrochar product. For catalytic WT and HTC, relevant studies in different yet interrelated applications are overviewed, where insights are given based on the effect of catalyst addition on the properties of hydrochar and the promotion of ‘secondary deposits’. The ‘secondary deposits’ established in carbon material synthesis studies can reveal the relationship between catalyst addition and formation. On top of that, it also serves as a complimentary knowledge to enhance the understanding of how these deposits can be used to increase the higher heating value of the hydrochar, which is lacking in the existing hydrochar synthesis studies. Therefore, the aim of this review is to provide insights into the addition of catalysts for the synthesis of hydrochar for fuel application.

Insights into Proton Recombination in Ceramic Proton Conducting Electrodes

The effect of catalyst addition on H2 evolution from composite electrodes of La0.7Sr0.3TiO3 (LST) and BaZr0.1Ce0.7Y0.1Yb0.1O3−δ (BZCYYb) was studied. Starting with symmetric cells (LST∣∣BZCYYb∣∣LST), Pt was added to one or both electrodes, after which i–V polarization measurements were performed in humidified H2 at 723 and 773 K. The base cells showed very high impedances but these decreased dramatically upon addition of Pt to both electrodes. When Pt was added to only one electrode, the cells performed as diodes, showing that Pt was necessary for H2 dissociation but not for H recombination. The effects of adding Ru, W, Re and Fe were also studied. DFT calculations helped confirm that H recombination on BaZrO3 is expected to be barrierless. The implications of these results for potential application to electrochemical synthesis of ammonia are discussed.

The effect of catalyst addition on the structure, electrical and mechanical properties of the cross-linked polyurethane/carbon nanotube composites

Uniform distribution of filler particles in a polymer matrix is crucial to the improvement of properties of polymer composites. In this work, we have shown that control of the polymerization rate by addition of the catalyst (Fe(acac)3) hinders filler aggregation and enhances electrical and mechanical properties of polyurethane/nanotube composites. Thus, a percolation threshold value of 0.02 wt % obtained for the composites with the catalyst was much lower than the value of 0.65 wt % for the composites without the catalyst. Moreover, the electrical conductivity of the catalytically prepared composites at a nanotube content of 3 wt % was two orders of magnitude higher than that of the non-catalytically prepared ones. The tensile strength of both types of composites showed an improvement at lower filler concentrations, however, the increase of filler content led to deterioration of the mechanical properties for the non-catalytically prepared composites. Structure of the composites was investigated by means of optical and scanning electron microscopy. Additionally, the current-voltage characteristics (J-E) of the composites were studied.

17.超臨界水を用いた石炭・バイオマス同時液化プロセスにおける触媒添加効果

17.超臨界水を用いた石炭・バイオマス同時液化プロセスにおける触媒添加効果

Production of crude bio-oil via direct liquefaction of spent K-Cups

Spent K-Cups were liquefied into crude bio-oil in a water-ethanol co-solvent mixture and reaction conditions were optimized using response surface methodology (RSM) with a central composite design (CCD). The effects of three independent variables on the yield of crude bio-oil were examined, including the reaction temperature (varied from 255 °C to 350 °C), reaction time (varied from 0 min to 25 min) and solvent/feedstock mass ratio (varied from 2:1 to 12:1). The optimum reaction conditions identified were 276 °C, 3 min, and solvent/feedstock mass ratio of 11:1, giving a mass fraction yield of crude bio-oil of 60.0%. The overall carbon recovery at the optimum conditions was 93% in mass fraction. The effects of catalyst addition (NaOH and H2SO4) on the yield of crude bio-oil were also investigated under the optimized reaction conditions. The results revealed that the presence of NaOH promoted the decomposition of feedstock and significantly enhanced the bio-oil production and liquefaction efficiency, whereas the addition of H2SO4 resulted in a negative impact on the liquefaction process, decreasing the yield of crude bio-oil.

Study on Catalytic Combustion of Biomass Mixtures with Poor Coals

The effect of catalyst addition on ignition and combustion characteristics of biomass fuels from the Mediterranean region, one lignite and lignite/biomass blends, were investigated. Transition metal oxides and alkali/alkaline earth compounds were used as catalysts. The experiments were conducted in a thermogravimetric analysis system. The performance of the process was evaluated in terms of combustion rate, ignition, and combustion indices. The results showed that metal oxides enhanced the ignition and combustion performance of lignite, showed no catalytic activity to burn off of biomass fuels, but influenced the temperature sensitivity of their reaction in air. The relative activity was in the following order: V2O5>Fe2O3>CaO>NaCl>MgO>CuO>TiO2>LiCl. The combustion characteristics of the blends followed those of parent fuels in an additive manner. Blending lignite with biomass fuels increased its thermochemical reactivity. In terms of burnout, catalyzed combustion of blends was further improved.

Gasification of Waste Biomass Chars by Carbon Dioxide via Thermogravimetry—Effect of Catalysts

The effect of catalyst addition on thermal conversion characteristics and kinetics of waste biomass chars was investigated. The experiments were performed in a thermogravimetric analysis system, at non-isothermal heating conditions, under a carbon dioxide atmosphere. Reaction rates were determined by a power law model. The bulk of char gasification process occurred between 800 °C and 950 °C. Addition of alkali salts improved char conversion and increased the reactivity of the samples by lowering the reaction temperature. Peak values were reduced by 4 to 138 °C. The catalytic activity was enhanced when 10% Na2CO3, 10% CaCO3, and 10% Li2CO3 were used during the gasification of municipal solid wastes, sewage sludge, and waste paper, respectively. Alkali carbonates and especially binary mixtures of them increased the reactivity of the fuels by significantly reducing the activation energy. Activation energies ranged from 180 to 370 kJ/mol without catalysts, whereas from 82 to 353 kJ/mol with catalyst addition.

Effect of catalyst additives on the production of biofuels from palm oil cracking in a transport riser reactor

Catalytic cracking of crude palm oil (CPO) and used palm oil (UPO) were studied in a transport riser reactor for the production of biofuels at a reaction temperature of 450 °C, with residence time of 20 s and catalyst-to-oil ratio (CTO) of 5 g g −1. The effect of HZSM-5 (differrent Si/Al ratios), beta zeolite, SBA-15 and AlSBA-15 were studied as physically mixed additives with cracking catalyst Rare earth-Y (REY). REY catalyst alone gave 75.8 wt% conversion with 34.5 wt% of gasoline fraction yield using CPO, whereas with UPO, the conversion was 70.9 wt% with gasoline fraction yield of 33.0 wt%. HZSM-5, beta zeolite, SBA-15 and AlSBA-15 as additives with REY increased the conversion and the yield of organic liquid product. The transport riser reactor can be used for the continuous production of biofuels from cracking of CPO and UPO over REY catalyst.

Effect of catalyst addition on gasification reactivity of HyperCoal and coal with steam at 775–700 °C

HyperCoal is a clean coal with ash content <0.05 wt%. HyperCoal was prepared from a bituminous coal by solvent extraction method with an extraction yield of 66.7%. Effect of K 2CO 3 loading and temperature on steam gasification rate of HyperCoal and parent raw coal was investigated. Experiments were carried out at 775 and 700 °C for both HyperCoal and coal with 0–25% catalyst loading. Gasification rates increased with increased catalyst loading and reached a value above which rates did not change with catalyst loading. The catalyst loadings were 6% for HyperCoal and 20% for coal. The difference is most likely due to the difference in ash content of HyperCoal and coal and not due to the effect of H 2 inhibition on the rate. In the presence of catalyst effect of temperature was only on gasification rate and total gas yield and gas composition were unaffected.

Catalyst addition in polyethylene pyrolysis: Thermogravimetric study

The effect of catalyst addition on the thermal decomposition of low-density polyethylene has been studied. The pyrolysis has been studied in a thermobalance, using polyethylene mixed with different catalysts, such as MCM41, USY and ZSM-5. The study comprises the analysis of various effects, including the amount of catalyst added and the type of catalyst. It has been observed that almost all the catalytic effect is obtained for a given amount of added catalyst, and a further increase in the catalyst added does not produce a further reduction in the decomposition temperature. A kinetic model has been applied which allows a very good correlation of all the runs performed using the same catalyst. The model involves two different ways for the decomposition, one catalysed and the other non-catalysed. The order of the non-catalysed reaction has been allowed to vary, yielding reaction orders close to zero (i.e. very similar to that found in several thermogravimetric studies of polyethylene decomposition). On the other hand, the catalysed reaction has a rate constant with a saturating dependence with the concentration of the catalyst.

1-7.モデル石炭中窒素の熱分解挙動に及ぼす触媒の添加効果(Session 1 石炭・重質油)

1-7.モデル石炭中窒素の熱分解挙動に及ぼす触媒の添加効果(Session 1 石炭・重質油)

00/00637 Effect of catalyst addition on co-liquefaction process of coal and biomass in supercritical water

00/00637 Effect of catalyst addition on co-liquefaction process of coal and biomass in supercritical water

Effect of Catalyst Addition on Subatmospheric Burning Surface Temperature of Composite Propellants

The subatmospheric burning with its higher catalytic effectiveness, lower temperature gradient, and slower combustion wave offers a Ž tting environment to study the effect of catalysts on the burning surface temperature of composite propellants. Using platinum and platinum-13% rhodium 7.5m thermocouples in uncatalyzed as well as copper–chromite-catalyzed ammonium perchlorate/hydroxyl-terminated polybutadiene composite propellants, the subatmospheric-burning surface temperatures were measured. The results of the present experimental study are in close agreement with the established trend; the surface temperature increases with the increase in pressure. Some experimental studies of others failed to give an observable change in surface temperature with pressure. This is argued to be because of the dimensional inadequacy of detectors in the very high-temperature-gradient environment. The measured surface temperature of the catalyzed propellant is signiŽ cantly higher than that of the uncatalyzed one. The study shows that the increased surface and subsurface heat release caused by catalyst addition causes this temperature enhancement.

A mechanistic investigation and kinetic analysis of the thermal decomposition of diammonium hexanitrato cerate catalysed by Cd xCo 1− xFe 2O 4 catalysts

The isothermal and non-isothermal decomposition of pure diammonium hexanitrato cerate(IV) and its mixtures with 10% (wt/wt) of Cd xCo 1− x Fe 2O 4 catalysts (x = 0.0, 0.5 and 1.0) were investigated. The effect of catalyst additives on the kinetics of isothermal decomposition of the parent salt was also studied. Their isothermal curves of fraction decomposed (α) against time were sigmoid in nature and the decomposition reaction in the presence of these catalyst additives obeys the Avrami-Erofe'ev equation. Such catalytic pretreatment reduced the induction period to the onset of the reaction decomposition. From the complementary consideration of microscopic observations and kinetic evidence, we conclude that the thermal decomposition of the parent salt in the presence of these catalyst additives, in the temperature range 250–325 ° C, proceeds by the nucleation-and-growth mechanism. The promotional effect of the catalysts used was also described. It can be stated that the activity of these catalysts in promoting salt breakdown is a consequence of their appreciable solubility in the parent salt and that the chemistry of the reaction in such conditions is complicated. It involves several participants, including the unstable ammine complexes of both Cd and Co ions, located in the octahedral sites of the catalysts, formed as intermediates of the type [M(NH 3)] 6 2+.