Showing papers on "Partial oxidation published in 1999"
TL;DR: In this article, two aluminophosphate molecular sieves containing isolated, four-coordinated Co(III or Mn(III) ions are substituted into the framework and act, in concert with the surrounding framework structure, as regioselective catalysts for the oxidation of linear alkanes by molecular oxygen.
Abstract: Terminally oxidized hydrocarbons are of considerable interest as potential feedstocks for the chemical and pharmaceutical industry, but the selective oxidation of only the terminal methyl groups in alkanes remains a challenging task. It is accomplished with high efficiency and selectivity by some enzymes; but inorganic catalysts, although inferior in overall performance under benign conditions, offer significant advantages from a processing standpoint1. Controlled partial oxidation is easier to achieve with ‘sacrificial’ oxidants, such as hydrogen peroxide2, alkyl hydroperoxides oriodosylbenzene3, than with molecular oxygen or air. These sacrificial oxidants, themselves the product of oxidation reactions, have been used in catalytic systems involving tailored transition-metal complexes in either a homogeneous state4,5,6, encapsulated in molecular sieves7,8,9 or anchored to the inner surfaces of porous siliceous supports10. Here we report the design and performance of two aluminophosphate molecular sieves containing isolated, four-coordinated Co(III) or Mn(III) ions that are substituted into the framework and act, in concert with the surrounding framework structure, as regioselective catalysts for the oxidation of linear alkanes by molecular oxygen. The catalysts operate at temperatures between 373 K and 403 K through a classical free-radical chain-autoxidation mechanism. They are thus able to use molecular oxygen as oxidant, which, in combination with their good overall performance, raises the prospect of using this type of selective inorganic catalyst for industrial oxidation processes.
369 citations
Book•
01 Jan 1999
TL;DR: In this article, Chemical Depolymerization Gasification and Partial Oxidation Thermal Processes Catalytic Cracking and Reforming Hydrogenation Concluding Remarks Subject Index.
Abstract: Introduction Chemical Depolymerization Gasification and Partial Oxidation Thermal Processes Catalytic Cracking and Reforming Hydrogenation Concluding Remarks Subject Index.
236 citations
TL;DR: At least 85 percent selectivity to ethylene at greater than 70 percent conversion can be obtained by partial oxidation of ethane by adding large amounts of H(2) to the reaction mixture and using a platinum-tin catalyst operating at 950 degrees C with a contact time of approximately 10-3 seconds.
Abstract: At least 85 percent selectivity to ethylene at greater than 70 percent conversion can be obtained by partial oxidation of ethane by adding large amounts of H2 to the reaction mixture and using a platinum-tin catalyst operating at 950°C with a contact time of ∼10−3 seconds. This system almost totally shuts off the reactions that form undesired CO and CO2, which fall from 20 percent without H2 to 5 percent when H2is added. Although a 2/1 H2/O2 mixture should be explosive at high temperatures, no flames or explosions occur in the presence of ethane. The successive reactions on the catalyst generate more H2 than used in the feed, so with recycle no additional H2 would be needed. These results are unexpected because ethylene is a nonequilibrium product and entropy considerations argue that all reaction channels open at high temperatures so the products should approach equilibrium, which predicts only a few percent ethylene. This process is promising for the replacement of steam cracking in the production of ethylene.
223 citations
TL;DR: In this paper, the oxidation state of alumina-and titania-supported Ru catalysts has been investigated as a function of reduction temperature, as well as by following the interaction with a methane−oxygen mixture at 773 and 973 K, employing XPS and FTIR techniques.
Abstract: The oxidation state of alumina- and titania-supported Ru catalysts has been investigated as a function of reduction temperature, as well as by following the interaction with a methane−oxygen mixture at 773 and 973 K, employing XPS and FTIR techniques. It is found that the chemical behavior of Ru depends strongly on the material on which it is supported. Over Al2O3, ruthenium is incompletely reduced by treatment with hydrogen at 573 and 823 K, while oxidized Ru species are also detected following exposure of the catalyst to a methane−oxygen mixture at 773 and 973 K. In contrast, over TiO2, ruthenium is more easily reduced and is stabilized in its reduced state following hydrogen treatment at 823 K. During treatment with the methane−oxygen mixture, no reoxidation of Ru occurs. The interaction between Ru and TiO2, which inhibits the oxidation of ruthenium under conditions of partial oxidation of methane, is related to the unique ability of the Ru/TiO2 catalyst to promote the direct route of synthesis gas for...
203 citations
TL;DR: In this article, a series of ternary hydrotalcite-like layered double hydroxides (LDHs) with (Mg+Mn)/Al atomic ratios of ∼3 and Mg:Mn atomic ratios ranging from 3:0 to 0:3 were synthesized by a co-precipitation method.
202 citations
TL;DR: In this paper, the effect of the solid solution formation between NiO and MgO on the reaction of methane to synthesis gas was investigated, and the reaction mechanism was found to be dominant at 700°C and 750°C, but the combustion reforming mechanism also played a part.
Abstract: The following issues regarding the partial oxidation of methane to synthesis gas, over NiO/MgO solid solution catalysts, at a very high space velocity of the feed gas (CH 4 /O 2 =2/1, GHSV=720 000 cm 3 /g h), were investigated: (i) the effect of the solid solution formation between NiO and MgO on the reaction; (ii)the effect of the composition of the catalyst; and (iii) the reaction mechanism. It was found that the mechanical mixtures of NiO and MgO have low activity and selectivity; however, their activity and selectivity became higher with increasing calcination time, due to the formation of a NiO–MgO solid solution. In contrast, the solid solution catalysts prepared via impregnation provided high activity and selectivity, as well as high stability over a large range of NiO concentrations. However, the activity was low for too low concentrations of NiO in NiO/MgO and the catalyst was no longer stable for too high concentrations of NiO. By comparing, under the same reaction conditions, the rate of partial oxidation of methane for CH 4 /O 2 =2/1 to that of the reforming reaction of a mixture CH 4 /H 2 O/CO 2 obtained from the former by complete combustion, one could conclude that the pyrolysis mechanism was dominant at 700°C and 750°C, but at 850°C, the combustion reforming mechanism also played a part.
183 citations
TL;DR: In this article, the authors describe progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes and show that the specific energy consumption in the plasma reforming processes is 16 MJ/kg H 2 with high conversion efficiencies.
180 citations
TL;DR: In this paper, a mixed LaNixFe(1−x)O3 perovskite oxides (0≤x≤1) were prepared by a sol-gel related method, characterised by X-ray diffraction (XRD), specific surface area measurements, transmission electron microscopy (TEM) coupled to an energy dispersive Xray spectrometer (EDS).
Abstract: Mixed LaNixFe(1−x)O3 perovskite oxides (0≤x≤1) have been prepared by a sol–gel related method, characterised by X-ray diffraction (XRD), specific surface area measurements, transmission electron microscopy (TEM) coupled to an energy dispersive X-ray spectrometer (EDS). These systems are the precursors of highly efficient catalysts in partial oxidation of methane to synthesis gas. Studies on the state of these systems after test show the stabilisation of active nickel by increasing the amount of iron. These systems permit to control the reversible migration of nickel from the structure to the surface. The best mixed perovskite for the partial oxidation of methane is LaNi0.3Fe0.7O3.
180 citations
TL;DR: In this paper, a series of CeO2-ZrO2 composite oxides (Ce1−xZrxO2) was characterized and tested for the gas-solid reaction with CH4 in the absence of gaseous oxidant.
Abstract: A series of CeO2–ZrO2 composite oxides (Ce1−xZrxO2) was characterized and tested for the gas-solid reaction with CH4 in the absence of gaseous oxidant. A solid solution with fluorite structure was formed for the samples with Zr content below 50% (x ≤ 0.5). For Ce1−xZrxO2 both desorption of O2 and reduction by H2 took place at lower temperatures as compared with that for CeO2 alone. Like CeO2, the reaction of Ce1−xZrxO2 with CH4 selectively produced synthesis gas with a H2/CO ratio of 2, but the formation rates of H2 and CO were increased and the activation energy was remarkably decreased due to the incorporation of ZrO2 into CeO2. The reaction was further accelerated by the presence of Pt catalyst. The conversion of CH4 to H2 and CO could be achieved at a temperature as low as 500°C by using Ce0.8Zr0.2O2 in the presence of Pt. The reduced Ce0.8Zr0.2O2−y could be oxidized with H2O back to Ce0.8Zr0.2O2, producing pure H2 simultaneously.
179 citations
TL;DR: A series of alkali and/or alkali-earth-promoted, carbon-supported Ru catalysts have been prepared by impregnation from aqueous solutions of the precursors as discussed by the authors.
Abstract: A series of alkali- and/or alkali-earth-promoted, carbon-supported Ru catalysts have been prepared by impregnation from aqueous solutions of the precursors. The supports have been pretreated by heating in inert atmosphere at various temperatures, followed by partial oxidation in air at 425°C and then by hydrogen treatment at 900°C. The catalyst samples, diluted 1/22 with quartz powder, have been studied in ammonia synthesis by means of a bench-scale, downflow, continuous, tubular reactor, under standard reaction conditions (430°C, 100 bar total pressure, H2/N2 = 1.5/1 feeding ratio). Caesium and Barium proved to be much more effective promoters than Potassium as promoters and the optimal temperature range for support pretreatment was found to be about 1900°C. The ammonia productivity, on a catalyst volume basis, of our best Ru catalyst was about twice higher than that of the most widely used Fe-based commercial catalysts.
135 citations
TL;DR: In this paper, a density functional theory calculation on the oxidation of ethene over Ti−silicate catalysts within the cluster approximation was performed using the BP86 functional and a DZVP basis.
Abstract: Density functional theory calculations are presented on the oxidation of ethene over Ti−silicate catalysts within the cluster approximation. Results using the BP86 functional and a DZVP basis sugge...
TL;DR: In this article, the performance of the syngas-to-dimethyl ether (DME) reactor was optimized with respect to the feed gas composition and the optimal reactor feed gas system was integrated with synthesis gas generators.
Abstract: Process schemes for single-step syngas-to-dimethyl ether (DME) were developed in two stages: (1) the performance of the syngas-to-DME reactor was optimized with respect to the feed gas composition and (2) the optimal reactor feed gas system was integrated with synthesis gas generators. It was shown that the reactor performance is very sensitive to the H2:CO ratio in the feed gas. The optimal DME productivity and best material utilization were obtained with a feed gas containing 50% hydrogen and 50% carbon monoxide. In the second phase the syngas generation units considered were CO2−methane reformer, steam−methane reformer, methane partial oxidation, and coal gasifier. The integration adjusts the H2:CO ratio in natural gas-derived syngas to fit the optimal DME reactor operation and minimizes CO2 emissions and material loss. The technical feasibility of these schemes was demonstrated by simulations using realistic reactor models, kinetics, and thermodynamics under commercially relevant conditions.
TL;DR: In this paper, two kinds of oxides, reducible and irreducible, were used as supports, and the reaction behaviors of CH 4 /O 2 (2/1) over pure supports and the precalcined 1% Rh(O)/MgO catalysts were investigated in a pulse microreactor.
TL;DR: The reversible deactivation rate during gas-solid heterogeneous photocatalytic oxidation of airborne dilute o-xylene over near-ultraviolet irradiated titanium dioxide catalyst depends on o -xylene concentration and the relative humidity of the reactant stream as discussed by the authors.
TL;DR: In this paper, a mathematical model for industrial multitubular Fischer-Tropsch (F-T)-synthesis with nitrogen-rich syngas was developed, which showed that nitrogen plays an important role in removing the heat generated by the F-T-reaction.
Abstract: An option in bringing remote natural gas reserves to the market is its conversion by Fischer–Tropsch (F–T)-synthesis into diesel oil and wax The use of nitrogen-rich syngas (50 vol%) could be an alternative to classical processes with nitrogen-free syngas because the investment costs are probably lower: syngas is produced by partial oxidation with air, which eliminates the need for an air separation plant, and a process with nitrogen-rich syngas does not utilize a recycle loop and a recycle compressor For the development of such a process, the kinetics of F–T-synthesis was studied on an Fe-catalyst, indicating that nitrogen only dilutes syngas, and therefore, has no influence on the kinetics if the partial pressures of carbon monoxide and hydrogen are kept constant Subsequently, the F–T-synthesis with nitrogen-rich syngas was investigated in wall-cooled single tube reactors Based on the experimental data, a mathematical model for industrial multitubular F–T-reactors was developed Model calculations indicate that nitrogen plays an important role in the operation of multitubular reactors by helping to remove the heat generated by the F–T-reaction This leads to an optimum diameter of the tubes of 70 mm for nitrogen-rich syngas with respect to a stable and safe operation of the reactor, whereas for nitrogen-free syngas, the diameter is limited to about 45 mm The production rate of diesel oil and wax per tube is, in case of nitrogen-rich syngas, about three times higher, which will decrease the number of tubes and the investment costs of industrial multitubular reactors Detailed economic studies are still necessary to validate or disprove whether and under which circumstances the proposed process with nitrogen-rich syngas is an attractive alternative to classical processes with nitrogen-free syngas, especially in areas with remote natural gas resources
TL;DR: In this paper, an experimental technique has been developed to determine both δ 18 O and δ 17 O of hydrogen peroxide (H2O2) in natural water.
TL;DR: In this paper, a series of catalysts derived from CuZnAl hydroxycarbonate precursors containing hydrotalcite-like layered double hydroxide as a major phase were used for partial oxidation of methanol (POM) reaction.
Abstract: Hydrogen production by partial oxidation of methanol (POM) reaction (CH3OH + (1/2)O2 ⇌ 2H2 + CO2) was investigated over a series of CuZnAl ternary oxide catalysts derived from CuZnAl hydroxycarbonate precursors containing hydrotalcite‐like layered double hydroxide as a major phase. These catalysts exhibited a good catalytic activity and high H2 selectivity. A methanol conversion of about 40–60% was obtained at 200°C with high selectivity of H2 and CO2. The undesirable by‐product, CO was virtually not produced over most of the catalysts at this temperature. The catalytic activity was found to decrease with increasing (Cu + Zn)/Al atomic ratio in the precursor and, was correlated with Cu metal surface areas, Cu dispersion and Cu particle sizes, which were calculated by both XRD and TPR‐N2O passivation methods. The catalyst with higher Cu surface areas and Cu dispersion displayed a higher catalytic activity. Lifetime experiments showed that these catalysts were stable over a period of 24 h of continuous operation. Catalyst precursors containing hydroxycarbonates other than LDH as a major phase offered considerable amount of dimethyl ether as a by‐product.
Patent•
01 Sep 1999
TL;DR: In this article, a process and a catalyst for the partial oxidation of paraffinic hydrocarbons, such as ethane, propane, naphtha, and natural gas condensates, to olefins, was presented.
Abstract: A process and catalyst for the partial oxidation of paraffinic hydrocarbons, such as ethane, propane, naphtha, and natural gas condensates, to olefins, such as ethylene and propylene. The process involves contacting a paraffinic hydrocarbon with oxygen in the presence of hydrogen and a catalyst under autothermal process conditions. Preheating the feed decreases oxygen consumption and increases the net hydrogen balance. The catalyst comprises a Group 8B metal, preferably, a platinum group metal, and at least one promoter selected from Groups 1B, 6B, 3A, 4A, and 5A, optionally supported on a catalytic support, such as magnesia or alumina. In preferred embodiments, the support is pretreated with a support modifier selected from Groups 1A, 2A, 3B, 4B, 5B, 6B, 1B, 3A, 4A, 5A, the rare earth lanthanides, and the actinides. A modified fluidized bed reactor is disclosed for the process.
TL;DR: In this paper, a range of metal-containing silicalite and aluminophosphate catalysts were used for the partial oxidation of glycerol, and it was found that increasing the pore size from ca. 0.5 nm to 15 nm for a titania-silica co-gel significantly increased the formation of partial oxidation products.
Abstract: The oxidation of glycerol using a range of metal‐containing silicalite and aluminophosphate catalysts is described and discussed. Variation in reaction conditions (extent of conversion, temperature, glycerol/hydrogen peroxide ratio) or catalyst (silicalite containing Ti, V, Fe or AlPO‐5 containing Cr, V, Mn, Co) did not lead to the formation of partial oxidation products of glycerol. Formic acid and a mono‐formate ester of glycerol were observed to be the major products together with a complex mixture of acetals. Increasing the pore size of the catalyst was investigated for Ti‐containing materials and it was found that increasing the pore size from ca. 0.5 nm for TS‐1 to 15 nm for a titania–silica co‐gel significantly increased the formation of partial oxidation products of glycerol, namely glyceraldehyde, dihydroxyacetone and glyceric acid.
TL;DR: In this paper, the performance of PEMFCs with a catalytic sheet was evaluated at 1000 ppm CO in hydrogen with 5% air bleed at 80°C and a reaction rate of 2·10 −3 mol CO/s g Au.
TL;DR: In this article, an acid site related active site is proposed for gas phase methanol partial oxidation on a highly ordered vanadium substituted MCM-41, which has an isolated tetrahedral coordination with surrounding oxygen anions.
Abstract: Gas phase methanol partial oxidation was carried out on a highly ordered vanadium substituted MCM-41 and an acid site related active site is proposed for this reaction. All synthesized samples showed similar values for the methanol percent conversion and the formaldehyde selectivity independent of the vanadium content. The turnover frequency of methanol and formaldehyde was also similar when it was normalized by the accessible active site concentration measured by the oxygen titration at reaction temperature. The active site concentration was found to be correlated with the acid site concentration of V-MCM-41. The main active site is proposed to be a weak Lewis acid site, which has an isolated tetrahedral coordination of vanadium with surrounding oxygen anions. V-MCM-41 is a stable catalyst against gas phase methanol oxidation at 350°C. The saturation value of vanadium concentration in this catalytic system was estimated to be 0.41 wt.%, and produces a very stable isolated tetrahedral coordination V site.
TL;DR: In this paper, the authors used a trickle-bed reaction for catalytic wet air oxidation of an aqueous phenol solution at mild conditions of temperature (120-160°C) and oxygen partial pressure (0.6-1.2 MPa).
TL;DR: In this article, a series of mesoporous vanadosilicate V-MCM-41 molecular sieves with variable Si/V ratios have been hydrothermally synthesized at pH = 10.
Abstract: A series of mesoporous vanadosilicate V-MCM-41 molecular sieves with variable Si/V ratios have been hydrothermally synthesized at pH = 10. These materials were investigated by powder X-ray diffraction (XRD), framework FTIR, diffuse reflectance UV−visible spectroscopy, nitrogen sorption measurement, scanning electron microscopy, transmission electron microscopy (TEM), thermogravimetric analysis, and differential thermal analysis. XRD and FTIR showed that the solid products had the MCM-41 structure and contained only atomically dispersed vanadium consistent with framework vanadium in V-MCM-41. Nitrogen sorption results showed that all of the materials had a uniform pore size distribution with pore size of around 3.0 nm. The crystallinity of V-MCM-41 decreased with an increase of the vanadium content. The hexagonal array structure of uniform pore size was observed by TEM. It proved that the pores were highly aligned. The catalytic activities of V-MCM-41 were tested in the partial oxidation of benzene by dilu...
TL;DR: In this paper, the authors studied the thermal deactivation process of the deep photocatalytic oxidation of acetone and deduced the presence of two types of adorption sites from two O bands of adsorbed acetone.
Patent•
23 Mar 1999TL;DR: In this paper, a process for the catalytic generation of hydrogen by the self-sustaining combination of partial oxidation and steam reforming of a hydrocarbon comprises contacting a mixture of the hydrocarbon, an oxygen-containing gas and steam with a catalyst comprising rhodium dispersed on a refractory oxide support material.
Abstract: A process for the catalytic generation of hydrogen by the self-sustaining combination of partial oxidation and steam reforming of a hydrocarbon comprises contacting a mixture of the hydrocarbon, an oxygen-containing gas and steam with a catalyst comprising rhodium dispersed on a refractory oxide support material which is a mixture of ceria and zirconia. The hydrocarbons are straight chain or branch chain hydrocarbons having 1 to 15 carbon atoms and include methane, propane, butane, hexane, heptane, normal-octane, iso-octane, naphthas, liquefied petroleum gas and reformulated gasoline petrol and diesel fuels. The hydrogen generation process can be started by feeding the hydrocarbon and air to initiate partial oxidation, before steam is added. The hydrogen generation process also may be operated in combination with a water-gas shift reaction for the reduction of carbon monoxide in the hydrogen generated.
TL;DR: In this article, a reduced H 3 PMo 12 O 40 (Py) catalyst was shown to have a high potentiality in the propane and isobutane oxidation with molecular oxygen to acrylic acid and methacrylic acid.
Abstract: When molybdophosphoric acid, H 3 PMo 12 O 40 , was treated with pyridine and heated in N 2 flow at 420°C as an optimized temperature, a black solid catalyst was formed with a structure of orthorhombic phase and in a reduced state. This reduced H 3 PMo 12 O 40 (Py) catalyst showed a high potentiality in the propane and isobutane oxidation with molecular oxygen to acrylic acid and methacrylic acid above 300°C. It was proved that the higher the reduction degree of the catalyst is, the higher the oxidation activity and selectivity to partial oxidation products are. The FT-IR study revealed that, in the lattice of the heat-treated H 3 PMo 12 O 40 (Py) catalyst, pyridinium ion remained to assume the highly resistant orthorhombic secondary structure against reoxidation, and on the surface, Lewis acid sites were generated with the formation of the primary oxygen-deficient Keggin structure. A possible reaction mechanism was proposed for alkane oxidation, where protons and electrons in the reduced H 3 PMo 12 O 40 (Py) catalyst cooperate to activate molecular oxygen.
TL;DR: In this article, an annular plug flow reactor with TiO2 in a supported form was used for photocatalytic oxidation of the sulfur-containing compounds, trimethylene sulfide (C3H6S), propylene sulfide, thiophene (C4H4S), and methyl disulfide.
Abstract: Photocatalytic oxidation of the sulfur-containing compounds, trimethylene sulfide (C3H6S), propylene sulfide (C3H6S), thiophene (C4H4S), and methyl disulfide (C2H6S2), was carried out using an annular plug flow reactor with TiO2 in a supported form. Formation of products and byproducts was monitored in real time using a mass spectrometry online system. Mineralization of the sulfur-containing compounds was confirmed by mass balance of CO2 and SO42-. Dilute contaminated atmospheres of trimethylene sulfide and propylene sulfide were completely mineralized. For thiophene and methyl disulfide, however, partial oxidation was observed, generating sulfur dioxide (SO2) and sulfur oxide (SO) as byproducts, which were confirmed by parent ion MS/MS spectra as well as by chemical ionization. Sensory analysis showed that for trimethylene sulfide and propylene sulfide, odor intensity after TiO2/UV treatment was below the olfactive threshold limit of the panel.
TL;DR: Advantages and limitations of laser Raman spectroscopy (LRS) for the study of catalytic materials and surfaces under working conditions are discussed in this paper, where several examples are presented of in situ LRS studies including the phase analysis of bismuth molybdate and VPO oxidation catalysts, synergy effects and oxygen exchange in Sb2O3/MoO3 oxide mixtures, intermediates in oxidative coupling of methane, NO decomposition on Ba/MgO catalysts.
Abstract: Advantages and limitations of laser Raman spectroscopy (LRS) as an in situ vibrational spectroscopy for the study of catalytic materials and surfaces under working conditions are discussed. Measurements can be carried out at temperatures as high as 1200 K in controlled atmospheres. Modern instrumentation permits time resolutions in the sub‐second regime for materials with high Raman cross sections. Transient studies are thus possible. Several examples are presented of in situ LRS studies including the phase analysis of bismuth molybdate and VPO oxidation catalysts, synergy effects and oxygen exchange in Sb2O3/MoO3 oxide mixtures, intermediates in oxidative coupling of methane, NO decomposition on Ba/MgO catalysts, and transient SERS studies of partial oxidation of methanol on Ag single crystal surfaces and of the reduction of oxide overlayers on electrodeposited Rh layers.
TL;DR: In this paper, a systematic investigation of the catalytic oxidation of 1,2-dichlorobenzene (o-DCB) was conducted over a series of supported vanadia/alumina catalysts.
TL;DR: In this article, a simplified reaction pathway was proposed to describe the kinetic behavior of catalytic wet oxidation of organic mixture, and the oxidation reactions were divided and lumped into two groups: (1) the deep or complete oxidation reactions with formation of CO2 and H2O; (2) the partial oxidation reactions in aqueous solution of the industrial wastewater.
Abstract: A simplified reaction pathway was proposed to describe the kinetic behavior of catalytic wet oxidation of organic mixture. The oxidation reactions were divided and lumped into two groups: (1) the deep or complete oxidation reactions with formation of CO2 and H2O; (2) the partial oxidation reactions with formation of all intermediates in aqueous solution of the industrial wastewater. The concentrations of all reactants in wastewater and those of the intermediates formed during the reaction are also represented by a lumped concentration of total organic carbon (TOC). To test the model, catalytic oxidation of organic pollutants in an effluent from a softwood Kraft pulp mill was investigated in a slurry reactor using a Pd-Pt/Al2O3 catalyst. Sodium hydroxide was used to adjust the initial pH of wastewater to 7.3 to avoid the problem of metal leaching and excessive corrosion. The lumped kinetic model developed in this study describes well both our experimental data and those reported in literature. The lumped kinetic model proposed in this study can be used for both catalytic and noncatalytic wet oxidation processes.