Desulphurization Reaction Research Articles

In vitro and in vivo studies on the metabolism and pharmacokinetics of the selective gut microbial β-glucuronidase targeting compound Inh 1

In vitro studies using rat, mouse, and human microsomes and hepatocytes on the bacterial β-glucuronidase inhibitor 1-((6,8-dimethyl-2-oxo-1,2-dihydroquinolin-3-yl)methyl)-3-(4-ethoxyphenyl)-1-(2-hydroxyethyl)thiourea) (Inh 1) revealed extensive metabolism in all species. The intrinsic clearances of Inh 1 in human, mouse, and rat hepatic microsomes were 30.9, 67.8, and 201 µL/min/mg, respectively. For intact hepatocytes intrinsic clearances of 21.6, 96.0, and 129 µL/min/106 cells were seen for human, mouse and rat, respectively. The metabolism of Inh 1 involved an uncommon desulphurisation reaction in addition to oxidation, deethylation, and conjugation reactions at multiple sites. Six metabolites were detected in microsomal incubations in human and rat, and seven for the mouse. With hepatocytes, 18 metabolites were characterised, 9 for human, and 11 for mouse and rat. Following IV administration to mice (3 mg/kg), plasma concentrations of Inh 1 exhibited a monophasic decline with a terminal elimination half-life of 0.91 h and low systemic clearance (11.8% of liver blood flow). After PO dosing to mice (3 mg/kg), peak observed Inh 1 concentrations of 495 ng/mL were measured 0.5 h post dose, declining to under 10 ng/mL at 8 h post dose. The absolute oral bioavailability of Inh 1 in the mouse was ca. 26%.

Numerical simulation of particle erosion coupled with flue gas desulphurization in the spouted bed

The addition of an axial swirl vane (ASV) and multi-jet distributor plate (MDP) to a conventional spouted bed (CSB) to form an integrated multi-jet swirling spouted bed (IMSSB) combined with internally reinforced components not only optimized its desulphurization efficiency but also exacerbated the erosion of particles on the bed and the internal components. Coupled study of the particle erosion and desulphurization reaction in the flue gas desulphurization process of an IMSSB was carried out based on the CPFD numerical simulation. The results show that: the desulfurization efficiency of IMSSB is increased by 16.6% compared with that of the CSB; in terms of wall erosion, the maximum erosion rate in IMSSB is about four times that of CSB; the erosion condition increases in the vane from the center to the edges; particle erosion is most severe in the fountain area.

Understanding the pore size distribution of Ca(OH)2 for effective desulfurization under low-to-medium temperatures

The pore size distribution plays a crucial role in the gas-solid desulfurization reaction of Ca(OH)2, yet its impact on desulfurization performance is not fully understood, especially in low-to-medium temperature range (100–400 °C). This study examined the diffusion and adsorption characteristics of SO2 in Ca(OH)2 pores with different sizes by Monte Carlo Simulation and Molecular Dynamics Methods. The reaction kinetics of desulfurization for samples with different pore structures were analyzed based on TGA data and linear regression. It is found that the adsorption of SO2 on Ca(OH)2 was mainly induced by electrostatic interaction. Pores with the size of 5–15 nm were most favorable for SO2 adsorption, with the maximum adsorption heat of 464.83 kJ/mol at 5 nm. When the pore size increased, the diffusion of SO2 was improved, but the distribution of SO2 became more scattered, resulting in an adverse effect on the desulphurization reaction. The desulphurization process can be divided into the surface reaction controlled stage and product layer diffusion controlled stage. The desulphurization ability was primarily contributed by the reaction controlled stage, in which Ca2+ migration resistance was the least. Pore structure was a crucial factor in determining the duration of the reaction controlled stage. The presence of 15–30 nm pores was of significant importance for this stage. Yet in the diffusion controlled stage, pores size of ≥30 nm was much more important than other sizes to improve the Ca2+ diffusion. This study shows that a reasonable pore size combination facilitates the diffusion of SO2 and its reaction with Ca2+.

The use of artificial neural network (ANN) in dry flue gas desulphurization modelling: Levenberg–Marquardt (LM) and Bayesian regularization (BR) algorithm comparison

AbstractThis research project aims to investigate the efficacy of artificial neural networks (ANN) in mapping dry flue gas desulphurization (DFGD). Bayesian regularization (BR) and Levenberg–Marquardt (LM) training algorithms were used for DFGD modelling. The input layer feed data contained diatomite to Ca(OH)2 ratio, hydration time, hydration temperature, sulphation temperature, and inlet gas concentration, while the output layer metadata were sorbent conversion and sulphation responses. The hyperbolic tangent (tansig), sigmoid (logsig), and linear (purelin) activation functions were compared to ascertain the best network learning model. The number of hidden layer cells also varied between 7 and 10, given the existence of multiple output feed data. BR and LM performance evaluation was based on coefficient of determination (R2), root mean square error (RMSE), and mean square error (MSE) mathematical analysis. BR was a superlative training tool compared to LM, with lower RMSE and MSE values. The goodness of fit data for both techniques was close to unity, clarifying that ANN using BR and LM tools can be used to predict DGFD outcome. The shrinking core model was used to analyze the desulphurization reaction and concluding the chemical reaction was the reaction controlling step.

Effect of CaO/Al2O3 ratio on desulphurization and non-metallic inclusions in low-density steel

ABSTRACT To determine the effect of the CaO/Al2O3 ratio on desulphurization and inclusion evolution in low-density steel, a series of laboratory-scale experiments are performed. The results show that violent reaction occurs at the interface between refining slag and molten steel. As the slag-steel reaction progresses, (CaO) and (MgO) are reduced to [Ca] and [Mg] by dissolved [Al]. The deoxidation product Al2O3 dissolves into the slag and accumulates at the slag-steel interface. The evolution process of the sulphide inclusions is CaS → MgS → MnS. The sulphide outer layer wraps AlN and spinel inclusions, floats up and is absorbed by the top slag. During refining process, the accumulated Al2O3 at the slag-steel interface easily forms MgO·Al2O3. Finally, a dense spinel layer can be formed at the slag-steel interface, which inhibits the desulphurization reaction. Reducing the C/A ratio can reduce the formation of MgO·Al2O3 and has a positive effect on the desulphurization in low-density steel. The influence of the C/A ratio on desulphurization kinetics should be considered in the design of slag composition.

Cucurbit[7]uril limits the binding of coumarin bearing alkyl-acetoacetate with mercury and stimulates the desulphurisation reaction of its sulphur analog

ABSTRACT The inclusion of 7-diethylamino-coumarin derivatives, bearing an ethyl acetoacetate (CAM1) and a methyl β-ketodithioester moiety (CAM2) in the cavity of cucurbit[7]uril (CB7), leads to different interaction forms with mercuric ions (Hg2+). The interaction between these ions and CAM1, in the presence of CB7, occurs through the lateral ethyl acetoacetate moiety of the keto form of CAM1, leading to the formation of binary assemblies such as Hg2+@CAM1 and Hg2+@CB7. As a consequence, the metal restricts the insertion of the dye into the CB7 cavity, decreasing the apparent binding constant between them. Interestingly, for the other derivative CAM2, a mercury-induced desulfurisation reaction of its β-ketodithioester moiety is kinetically accelerated by CB7 (by a factor ≈25), which subsequently leads to the generation of binary and ternary complexes among the analogue oxygenised from CAM2, metal and CB7. The later effect is a promising strategy that could be considered for the mercury sensing methodology.

A novel method for fuel oil desulphurization by deep eutectic solvent extraction coupled with reduction using sodium borohydride

AbstractIn order to improve sulphur removal efficiency, deep eutectic solvent (DES) is first introduced into the fuel oil desulphurization process with sodium borohydride (NaBH4). Thereby, a novel method for fuel oil desulphurization by extraction coupled with reduction is proposed, where DES is used as stabilizer and extractant and NaBH4 is used as reducing agent. The nickel borides produced from NaBH4 and nickel salts were characterized using a particle size analyzer, surface area analyzer, and transmission electron microscopy. The results show that the nickel borides produced in DES have smaller particle sizes and a higher BET surface area than that in methanol/tetrahydrofuran (MeOH/THF). Sulphur removal efficiency using DES as medium was higher than that using MeOH/THF as medium. The effect of process parameters on the sulphur removal efficiency was investigated by orthogonal experiments. The results showed that the sulphur removal efficiency of dibenzothiophene can reach more than 96%. The desulphurization of dibenzothiophene should proceed over the cleavage of C−S bond to biphenyl and desulphurization reaction followed the pseudo‐first‐order reaction. The structures of the DESs remained unchanged after regeneration. In summary, the novel desulphurization method is feasible and promising.

Desulphurising high sulphur coal discards using an accelerated heap leach approach

A large amount of waste rock, coal discards and coal fines result from the extraction and beneficiation of coal. These wastes may present a major environmental hazard. Exposure of their sulphidic mineral content, mainly pyrite, to moisture and oxygen causes acidic runoff or leachate from waste rock dumps, coal discard dumps and tailings facilities, referred to as acid rock drainage (ARD). Whereas sulphide can be removed from fine coal waste by physical separation, it is sufficiently unliberated in coal discards or waste rock for ready physical separation. This requires either further liberation followed by removal using separation (energy consuming and costly) or removal by reaction. Heap bioleaching, a technology predominantly used for the recovery of base metals from low grade metal sulphide-containing ores, provides a sustainable option for the accelerated reaction of the pyritic fraction within the coal discards, allowing its removal in solution under controlled conditions during the life of mine for the long-term prevention of ARD. Easily implementable, heap bioleaching may constitute an economically viable prevention alternative to traditional ARD treatment methods. Further, such accelerated sulphide removal by reaction is expected to produce an environmentally benign discard with value prospects. The desulphurization reactions are sustained by iron- and sulphur oxidising microorganisms. The iron oxidizers catalyse the regeneration of the leach agent Fe3+ from its Fe2+ form, and the sulphur-oxidising microorganisms produce sulphuric acid from elemental sulphur and sulphides. These maintain highly acidic conditions which support further Fe2+ to Fe3+ oxidation and ongoing oxidation and leaching of the pyrite.In this study, proof of concept experiments were performed in laboratory scale columns over 380 days, simulating coal discard heaps. Coal discards containing 10.4% by mass pyritic sulphur were used. Results obtained indicated more than 50% desulphurisation in 250 days with a terminal duration of ~600 days predicted. This confirms the potential of heap bioleaching as a viable strategy for the desulphurisation of high sulphur-containing coal discards during life of mine, with their potential re-purposing as saleable coal or risk-reduced disposal.

Aromatisation and desulphurisation of liquefied petroleum gas over Zn-containing zeolite catalysts modified by transition metals

In this paper, treatment of liquefied petroleum gas (LPG) over Zn-containing zeolite catalysts modified by Mn, Cu and Fe was studied. The authors investigated catalytic activity in the aromatisation and desulphurisation reactions of propane-propylene and propane-butane fractions (PPF and PBF respectively). It was found that the feedstock composition did not actually affect conversion at elevated temperatures (550–600°C); however, yield of the resulting aromatic hydrocarbons was higher when using PPF. The activity of catalysts mainly depended on the structure and state of active sites and reaction conditions. During PPF desulphurisation, the Zn-Mn-ZSM-Al2O3 catalyst was the most active, while the Zn-Fe-ZSM-Al2O3 catalyst showed the highest activity with the PBF. Physical and chemical characteristics of the obtained catalysts were studied using various methods. [Received: September 20, 2017; Accepted: March 16, 2018]

A multiple-detection-point fluorescent probe for the rapid detection of mercury(II), hydrazine and hydrogen sulphide

A multiple-detection-point fluorescent probe (Probe 1) was developed for the rapid detection of mercury(II) (Hg2+), hydrazine (N2H4) and hydrogen sulphide (H2S). Probe 1 could detect Hg2+, N2H4 and H2S through different reaction sites and mechanisms, i.e. Hg2+ via a desulphurisation reaction, N2H4 via addition-cyclisation, and H2S via a nucleophilic addition reaction. N2H4 and H2S had hardly any effect on Hg2+ detection in C2H5OH, but Hg2+ interfered with N2H4 and H2S detection in DMSO, and Hg2+ and N2H4 interfered with H2S detection in DMSO. Rapid detection of Hg2+, N2H4 and H2S was achieved by a colour change in the test paper of Probe 1, which gradually turns dark in response to different concentrations of Hg2+, yellow with N2H4, and pink with H2S. Furthermore, Probe 1 could be used to detect Hg2+, N2H4 and H2S in real samples.

Precious metal mobility during serpentinization and breakdown of base metal sulphide

Serpentinization of ultramafic rocks drives geochemical exchange between the hydrosphere, biosphere and lithosphere in surficial environments and at depth. Precious metals are implicated in these hydration reactions because of the well-known association between peridotite-hosted Au and placer platinum-group mineral (PGM) deposits sourced from serpentinized ophiolite complexes at surface. However, the distribution of precious metals in mantle rocks and their mode of occurrence at the onset of serpentinization are not well understood because early-stage features are typically obliterated with progressive hydration. Herein we report electron probe microanalysis (EPMA) and laser ablation inductively coupled mass spectrometry (LA-ICPMS) spot and mapping results for a suite of base metal sulphide (pentlandite, pyrrhotite, chalcopyrite), native metal (Cu and Fe) and Ni-Fe alloy (awaruite) from variably serpentinized peridotite and pyroxenite (Late Permian to Early Triassic Nahlin ophiolite, Cache Creek terrane; Atlin, British Columbia, Canada). Pentlandite and pyrrhotite occur with magmatic clinopyroxene and Cr-spinel as ultrafine inclusions (few μm) and as coarser interstitial base metal sulphides (≤200 μm) that are enveloped by native metal (Cu and Fe) and Ni-Fe alloy. Because native Fe- and awaruite-bearing mineral assemblages require reduced and/or low-fS2 conditions, we suggest that these replacement textures document destabilization of base metal sulphide phases during the conversion of olivine to serpentine and magnetite. Desulphurization reactions decoupled precious metals from relict pentlandite at the microscale, with Ag, Pd, Pt and Au partitioning from sulphides into both awaruite and native metal (Cu and Fe) at concentrations up to 100s of ppm. New high-resolution LA-ICPMS maps also point to clusters of ultrafine PGM, tellurides, bismuthides and metal alloys that were either remobilized within the serpentinized mesh and/or represent the completely desulphidized product of ultrafine, intergranular base metal sulphide. Other PGE (Os and Ir) are mostly hosted within relict pentlandite and/or pyrrhotite that were preserved during incomplete desulphurization, along with lesser microscale remobilization of these elements into ultrafine veins. New whole-rock PGE (nickel-sulphide fire-assay; NiS-FA) results demonstrate that precious metal remobilization was limited to the microscale during the earliest stages of serpentinization, which, in the case of Au, is consistent with its low solubility within such reduced, low fS2 fluids. Precious metal mobility during the early stages of serpentinization may therefore depend on the stability of Ni-Fe alloy, native metal (Cu and Fe) and PGM. Progressive serpentinization, complete replacement of olivine and destabilization of the reduced, low-fS2 mineral assemblage likely represents an important process to liberate, transport and concentrate precious metals within more oxidized and/or sulphur-bearing fluids in surficial and deep subduction environments.

Sucrose facilitated synthesis of mesoporous silicoaluminophosphate SAPO-11 with different crystalline phases of MoO3 for highly-efficient oxidative desulfurization

The mesoporous silicoaluminophosphate SAPO-11 materials were synthesized by using the green and low-cost sucrose as template. The SAPO-11 were characterized by SEM, TEM, N2 physisorption and FT-IR. Sucrose was incorporated into the crystal structure of SAPO-11 crystals to form secondary mesoporosity. Meanwhile, the mesoporous MoVI/SAPO-11 samples with different MoO3 crystalline phases were synthesized. In addition, the pre-prepared optimal catalyst (with 3.6% molybdenum mass content) showed significantly high yield and durability for oxidative desulfurization (ODS). Interestingly, the yield of α-MoO3 composites was more than twice that of pure mesoporous SAPO-11 samples, due to the synergistic effect of secondary mesoporosity and molybdenum oxide. Then, the ODS reaction products were determined by GC–MS and 1H NMR. The leaching of active species in the liquid under the reaction conditions were evaluated. Besides, the kinetic properties were studied to calculate the activation energy of the reaction, and then a plausible mechanism of oxidative desulphurization reaction was also proposed.

Catalytic quality improvement of waste polyolefin originated fractions

Abstract The demand for alternative fuels having low greenhouse gases emission is continuously growing worldwide. Therefore it is preferred to produce new, waste originated components. One option is the recycling of plastic waste with cracking. The produced hydrocarbon fraction is not suitable for fuels thus it is important to improve its quality. The aim of our experimental work was to study the quality improvement of this cracked fraction (PPCGO) and crude oil based middle distillates (different composition) with co-processing. Our goal was to produce high quality diesel fuel blending components. We studied the effect of process parameters on the quality of products. Ni (2.3%) Mo (11.0%) P (2.3%)/Al2O3 catalyst was used. During the experiments we studied the hydrogenation of olefins, saturation of aromatics and desulphurization. The hydrogenation of olefins was practically complete at 300°C. It took place at significantly higher speed than the desulphurization reactions. In case of light gas oil feedstock the products had significantly lower sulphur contents; below 10 mg/kg already at 340°C. We determined that the cracked fraction had beneficial effect on the performance properties of the products. In case of all feedstock combinations, we found process parameters which can be used to produce high-quality diesel fuel blending components on the tested catalyst.

Aromatization and desulphurisation of liquefied petroleum gas over Zn-containing zeolite catalysts modified by transition metals

In this paper, treatment of liquefied petroleum gas (LPG) over Zn-containing zeolite catalysts modified by Mn, Cu and Fe was studied. The authors investigated catalytic activity in the aromatisation and desulphurisation reactions of propane-propylene and propane-butane fractions (PPF and PBF respectively). It was found that the feedstock composition did not actually affect conversion at elevated temperatures (550–600°C); however, yield of the resulting aromatic hydrocarbons was higher when using PPF. The activity of catalysts mainly depended on the structure and state of active sites and reaction conditions. During PPF desulphurisation, the Zn-Mn-ZSM-Al2O3 catalyst was the most active, while the Zn-Fe-ZSM-Al2O3 catalyst showed the highest activity with the PBF. Physical and chemical characteristics of the obtained catalysts were studied using various methods. [Received: September 20, 2017; Accepted: March 16, 2018]

Development of Synthetic Slag with Marble Waste and Calcium Aluminate Agents for Cast Iron Desulfurization

The aim of this work was to study the use of slags to desulfurize cast iron. It was proposed to use alumina instead of fluorspar. In addition, marble waste was used instead of lime. Simulations applying Thermo-Calc® software were carried out in order to obtain the theoretical phases using thermodynamic data. Then, a comparison between theoretical data and experimental tests were performed. Cast iron was melted in induction furnace at 1550oC. Slags composed mainly for CaO and Al2O3 were used to desulfurize cast iron. The results showed that the desulphurization reaction was favored when the liquid phase was increased. Furthermore, it was found that cast iron desulfurization occurs by top slag mechanism. Furthermore, the desulfurization tests showed a decrease up to 90.10% in the sulfur content to the mixture containing conventional lime and 87.25% to the mixture RMF15. The slags obtained from marble waste contained MgO, which it interfered negatively in the desulfurization yield. In addition, increasing the CaO particle diameter improved the desulfurization process. The desulphurization process more favored to particle size of 500-1000 µm.

Physical parameter-based allocation for the energy consumption of pyro-metallurgical system—a case study on nickel production in China

The objectives of this study were to establish an allocation model for the energy consumption of pyro-metallurgical system based on the physical relationship between the input and output, apply the established model to nickel production in China and compare the difference between the allocation results derived from the established model and the traditional models. The basic methodological idea of this study is that the energy input of a multi-output pyro-metallurgical process should be allocated according to how the energy input is consumed in the process. The energy consumption of pyro-metallurgical system was decomposed into different categories (e.g. energy absorption of chemical reaction and energy loss), and these categories were classified into two groups, i.e. the categories of energy consumption dependent on the product ratio (PRDE) and the categories of energy consumption independent on the product ratio (PRIE); then, the allocation basis for each category of energy consumption was determined through the physical relationship between the energy input and metal output. The allocation for the energy consumption of nickel production in China was carried out; the system boundary includes two sub-systems (i.e. Ni–Cu coproduction system and Ni refining system), and the energy consumption of the coproduction system should be allocated; the basic data required by the allocation model and the compilation of LCI were mainly obtained from literature. The energy consumption of the processes of mining, drying, converting and floating-grinding belongs to PRIE following the principle of mass-based allocation, and the corresponding allocation factors are 64, 64, 69 and 69 %, respectively. The categories of energy consumption involved in the smelting process (the key process for demonstrating the allocation model) include both PRIE and PRDE, and the aggregated allocation factor was calculated as 56 %. The allocation result derived from the established model is lower than the results derived from the mass-based model and the market value-based model, because that, through the desulphurization reactions that occurred in the smelting process, the chemical states of copper and nickel are transformed from copper pyrite (CuFeS2) and nicopyrite ((Fe,Ni)9S8) into cuprous sulphide (Cu2S) and nickel sulphide (Ni3S2), and copper compound releases more sulphur atoms than nickel compound. When analyzing a single pyro-metallurgical process, the result of allocation is sensitive to basis selection; however, when comparing two or more pyro-metallurgical processes, the comparison result of allocation is relatively insensitive to basis selection. The energy input of pyro-metallurgical system is consumed in different physical-chemical ways; the decomposition of energy consumption is significant for choosing allocation bases; the basis of mass can only be used for the allocation of PRIE, and choosing the same allocation basis for different cases without a systematic analysis will be inappropriate. The requirement of some nontraditional extra inventory data is the major limitation of the established model. This study mainly focused on how nickel production system consumes the energy input, and the energy consumption patterns of other production systems should be taken into account in future studies.

Mechanism of Selective Desulphurization in Iron Ore Sintering Process by Adding Urea

Abstract Iron ore sintering is an important part during the ironmaking process, and a large amount of SO2 is also generated. Our previous research shows that it is an effective way to reduce SO2 content of flue gas by adding urea to a special sintering material zone position. In this paper, the mechanism of selective desulphurization by adding urea during the iron ore sintering was carried out. The results show that 88.14 % desulphurization rate was obtained with the addition of 0.05 % urea particles at 100 mm height from the feed bottom. During the sintering process, when drying zone reached the added position of urea, large amounts of NH3 were generated by urea decomposition, and then reacted with SO2 to produce (NH4)2SO4 in the wetting zone. With the accumulated desulphurization reactions during the sintering, the low SO2 emission in the flue gas was achieved. Moreover, the addition of urea in the bottom zone avoided the ammonia present in the sintering ore and promoted the urea utilization efficiency.

Prediction model of sulphur distribution ratio between CaO–FeO–Fe2O3–Al2O3–P2O5 slags and liquid iron over large variation range of oxygen potential during secondary refining process of molten steel based on ion and molecule coexistence theory

A thermodynamic model for predicting sulphur distribution ratio LS between CaO–FeO–Fe2O3–Al2O3–P2O5 slags and liquid iron, i.e. the ion and molecule coexistence theory (IMCT)–LS model, has been developed for slags in a large variation range of slag oxidisation ability based on the IMCT. The developed IMCT–LS model has been verified with measured data of oxygen, phosphorus and sulphur distribution equilibria between the slags and liquid iron from the literature. The results indicate that the desulphurisation reaction is mainly controlled by reaction (CaO)+[S] = (CaS)+[O] in the reducing zone with the optimised standard molar Gibbs free energy change of ; the desulphurisation reaction is dominated by reaction (FeO)+[S] = (FeS)+[O] in the oxidising zone with the reported standard molar Gibbs free energy change of . The influence of CaO on the desulphurisation ability of the slags can be counteracted by that of FetO because higher CaO content corresponds to lower FetO content in the slags. An asymmetric V type relationship between sulphur distribution ratio LS and the mass action concentration ratio or or or , or the mass percentage ratio (%FeO)/(%CaO) or (%Fe2O3)/(%CaO) or (%FetO)/(%CaO) or the simplified complex basicity or optical basicity can be established for the slags equilibrated with liquid iron in a temperature range from 1811 to 1927 K (1538 to 1654°C). The abovementioned mass action concentration ratios or mass percentage ratios of various iron oxides to basic oxide CaO can be recommended to represent the comprehensive effect of iron oxides FetO and basic oxide CaO on desulphurisation ability of the slags.

Effect of activator on the structure and desulphurization efficiency of sludge-activated carbon

Sludge-activated carbons (SACs) prepared with excess of activated sludge are used to solve the problems of sludge disposal and odour pollution in a sewage treatment plant. For the preparation, ZnCl 2, KOH and H 2SO 4 are used as activators, respectively. The structure of the SACs are characterized by scanning electron microscope, X-ray photoelectron spectrometer, specific surface area and pore structure technologies, and the adsorption performance of H 2S is investigated. Results indicate that the desulphurization activity of SACs, whose activators are ZnCl 2 and KOH (SACZ and SACK), is better than that of carbon with H 2SO 4 as the activator (SACH). The breakthrough time of SACZ and SACK is up to 86 min, the sulphur capacity is 7.7 mg/cm3, and the maximal iodine value is 409.95 mg/g. While the breakthrough time of SACH is only 26 min with the sulphur capacity of 2.3 mg/cm3. A large percentage of pore volume with a diameter of 2–5 nm in the total pore volume is conductive to the desulphurization reaction. The large amount of surface acid functional groups is also helpful to the adsorption of H 2S. The desulphurization activity of SACZ and SACK is superior over that of commercial-activated carbon.

Preparation of bagasse Ash/MgO/ammonium acetate sorbent properties and modeling their desulphurization reaction

This work investigates the use of a siliceous material (bagasse ash) and a hydrating agent (ammonium acetate) as additives to enhance sulphur dioxide removal efficiency in low temperature dry flue gas desulphurization (FGD) process when magnesium‐based sorbent is used. Response surface methodology (RSM) was used to determine the effects of hydration temperature, hydration time, amount of ammonium acetate and amount of bagasse ash on the surface area of the sorbent. A polynomial model was developed to relate the preparation variables to the sorbent surface area. The Brunauer‐Emmet‐Teller (BET) surface area results show that the surface area increased from 56 m2/g to 219 m2/g when bagasse ash and ammonium acetate was used at different sorbent preparation conditions. The desulphurization experiments performed using a Thermo Gravimetric Analyzer (TGA) showed that sulphur dioxide (SO2) removal efficiency of up to 99.9% at reaction time of 2 h was achieved. The surface area results were in excellent agreement with the results obtained from the desulphurization reaction. The unreacted shrinking core model was chosen to describe the desulphurization reaction kinetics between SO2 and the magnesium hydrated sorbent. The model shows that a non‐porous shielding layer forms which stops further gas(SO2)‐solid (magnesium sorbent) reaction from occurring and the product layer was determined to be the rate limiting. The scanning electron microscope (SEM) results illustrates that as the sulphation reaction takes place pores become plugged with reaction products resulting to a non‐porous structure. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 23–31, 2015