Effect of Waste Oil-Cracking Catalyst Incorporation on Durability of Mortars

This paper presents research on transport properties and alkali-silica reaction (ASR) susceptibility of mortars containing a pozzolanic waste generated in the fluid catalytic cracking (wFCC) unit by the Portuguese oil-refinery. For this purpose, two series of mortars were prepared by partially replacing cement with 5%, 10% and 15% of wFCC catalyst. The main difference between the two series of mortars is the sand reactivity used in their composition. The results revealed that wFCC catalyst blended cement mortars exhibit an increased resistance against capillary water absorption and chloride migration, as well as a considerable inhibition effect on deleterious ASR expansion. However, under the adopted experimental conditions the incorporation of wFCC catalyst in mortars decreases their carbonation resistance.

Biodiesel production from green seaweed Ulva fasciata catalyzed by novel waste catalysts from Pakistan Steel Industry

This research article is based on the biodiesel synthesis from the marine green macroalga Ulva fasciata, collected from the coast of Karachi, Pakistan using new and the most potential waste catalysts from Pakistan Steel Industry.The oil was extracted with n-hexane then it was analyzed by GC, TLC and by the examination of fuel properties.The metal analysis of catalysts was carried out by chemical tests and flame atomic absorption spectroscopy(FAAS). The thermal treatment of catalysts at 1500–1700 °C during various processes in steel manufacturing industry converted the metals to metal oxides. The presence of CaO, MgO and ZnO in these catalysts made them highly reactive for biodiesel synthesis. The basicity of waste industrial catalysts was calculated to know their basic strength. The transesterification of U. fasciata oil was performed by fast stirring using 9:1 molar ratio of methanol/oil in the presence of seven different waste industrial catalysts for 6 h at 80–100 °C. The solid catalysts were easily separated from product for re-use. In addition, the rate of reaction in the presence of these catalysts was found to be quite feasible. The waste brown dust from the steel converter gave the highest yield(88%) of biodiesel. The production of biodiesel was confirmed by TLC examination and fuel properties in comparison with the ASTM standards.

Upcycling biomass waste into Fe single atom catalysts for pollutant control

Contaminants of heavy metals and antibiotics, which are frequently detected in water, soil and food chains with increasing prevalence in our current society, can cause potential harm to human health and disrupt human ecosystem irreversibly. Herein, we have successfully utilized biomass waste ferns contaminated by iron mines, to fabricate a first-of-its-kind high-performance class of Fe single-atom catalysts(FeSAC) by a facile pyrolysis. The optimal FeSAC-800 shows an excellent efficiency in the fastphotocatalytic degradation of six types of quinolone antibiotics(e.g., norfloxacin, levofloxacin, ciprofloxacin, enrofloxacin, lomefloxacin, flumequine) in 1 h under the simulated natural light irradiation. Based on advanced characterization, a well-defined structure of FeN_(4), confined in the porous carbon is elaborated for the FeSAC-800. Mechanism of the photodegradation is via a Fenton-like oxidation process whereas the reactive oxygen species play a key role. These findings open a new avenue for efficient, sustainable utilization of biomass waste in pollutant control.

Research on Catalytic Cracking Performance Improvement of Waste FCC Catalyst by Magnesium Modification

In this study,the deactivation mechanism caused by high accessibility of strong acid sites for the waste FCC catalyst was proposed and verified for the first time.Based on the proposed deactivation mechanism,magnesium modification through magnesium chloride impregnation was employed for the regeneration of waste FCC catalyst.The regenerated waste FCC catalyst was characterized,with its heavy oil catalytic cracking performance tested.The characterization results indicated that,in comparison with the unmodified waste FCC catalyst,the acid sites strength of the regenerated waste FCC catalyst was weakened,with no prominent alterations of the total acid sites quantity and textural properties.The heavy oil catalytic cracking results suggested that the catalytic cracking performance of the regenerated waste FCC catalyst was greatly improved due to the suitable surface acidity of the sample.In contrast with the unmodified waste FCC catalyst,the gasoline yield over the regenerated waste FCC catalyst significantly increased by 3.04 percentage points,meanwhile the yield of dry gas,LPG,coke and bottoms obviously decreased by 0.36,0.81,1.28 and 0.87 percentage points,respectively,making the regenerated waste FCC catalyst serve as a partial substitute for the fresh FCC catalyst.Finally,the acid property change mechanism was discussed.

Glycolysis Recycling of Waste Polyurethane Rigid Foam Using Different Catalysts

Dramatically increasing waste polyurethane rigid foam(WPRF)draws the attention of the world.A mixture of ethylene glycol(EG)and diethylene glycol(DEG)is used as glycolysis agents.WPRF was subjected to alcoholysis using different catalysts which are titanium ethylene glycol and potassium hydroxide to obtain recycled polyol,respectively.The effect of a different catalyst on the viscosity and hydroxyl value of recycled polyol is discussed.The regenerated polyurethane(RPU)is performed using the recycled polyol.Infrared spectrum,compressive strength,apparent density,water absorption,scanning electron microscope,and thermogravimetric analysis are carried out to investigate the effect of WPRF degradation using different catalysts.The results show that titanium glycol is more efficient than potassium hydroxide in almost all conditions.The viscosity of the recycled polyol is relatively low,and the hydroxyl value meets the requirements of industrial use.When the titanium glycol titanium addition amount is 0.05%,the prepared RPU has a compressive strength of 0.24 MPa,an apparent density of 41.75 kg/m^(3),and a good foam structure.Besides,the water absorption rate of the RPU under the two catalytic systems is not much different,and the thermal stability is good.The recycled polyol can generally partially replace traditional polyols to prepare polyurethane rigid foams with good comprehensive properties.

Recovery of vanadium and tungsten from waste selective catalytic reduction catalysts by K_(2)CO_(3) roasting and water leaching followed by CaCl_(2) precipitation

Waste selective catalytic reduction(SCR)catalysts are potential environmental hazards.In this study,the recovery of vanadium and tungsten from waste SCR catalysts by K_(2)CO_(3)roasting and water leaching was investigated.The roasting and leaching conditions were optimized:the leaching efficiencies of vanadium and tungsten were 91.19%and 85.36%,respectively,when 18 equivalents of K_(2)CO_(3)were added to perform the roasting at 900℃ for 2 h,followed by leaching at 90°C for 1 h.Notably,in the described conditions,the leaching rate of silicon was only 28.55%.Titanates,including K_(2)Ti_(6)O_(13)and KTi8017,were also produced.Si removal was achieved in 85%efficiency adjusting the pH to 9.5,and the Si impurity thus isolated was composed of amorphous Si.Tungsten and vanadium were precipitated using CaCl_(2).At pH 10 and following the addition of 0.10 mol of H_(2)O_(2)and 16 equivalents of CaCl_(2),the precipitating efficiencies of tungsten and vanadium were 96.89%and 99.65%,respectively.The overall yield of tungsten and vanadium was 82.71%and 90.87%,respectively.

Facile molybdenum and aluminum recovery from spent hydrogenation catalyst

Industrial catalyst waste has emerged as a hazardous pollutant that requires safe and proper disposal after the unloading process.Finding a valuable and sustainable strategy for its treatment is a significant challenge compared to traditional methods.In this study,we present a facile method for the recovery of molybdenum and aluminum contents from spent Mo-Ni/Al_(2)O_(3) hydrogenation catalysts through crystallization separation and coprecipitation.Furthermore,the recovered molybdenum and aluminum are utilized as active metals and carriers for the preparation of new catalysts.Their properties were thoroughly analyzed and investigated using various characterization techniques.The hydrogenation activity of these newly prepared catalysts was evaluated on a fixed-bed small-scale device and compared with a reference catalyst synthesized from commercial raw reagents.Finally,the hydrogenation activity of the catalysts was further assessed by using the entire distillate oil of coal liquefaction as the raw oil,specifically focusing on denitrogenation and aromatic saturation.This work not only offers an effective solution for recycling catalysts but also promotes sustainable development.

Novel efficient procedure for biodiesel synthesis from waste oils with high acid value using 1-sulfobutyl-3-methylimidazolium hydrosulfate ionic liquid as the catalyst

Preparation of biodiesel from waste oils containing 72% of free fatty acids catalyzed by a novel Br?nsted acidic ionic liquid 1-sulfobutyl-3-methylimidazolium hydrosulfate([BHSO_3MIM][HSO_4]) was systematically investigated.The optimum molar ratio of methanol to waste oils,catalyst amount,reaction temperature and reaction time were 8/1,10%(based on the mass of waste oils),140°C and 6 h,respectively,under which the obtained yield of biodiesel reached 94.9%.Also,[BHSO_3MIM][HSO_4] as a catalyst still retained around 97% of its original catalytic activity after successive re-use of 5 batches(6 h per batch),showing the excellent operational stability.Moreover,the acidic IL [BHSO_3MIM][HSO_4] was able to ef ficiently catalyze conversions of waste oils with different amounts of FFAs(free fatty acids) into biodiesel,and showed tremendous application potential.Therefore,an ef ficient and environmentally friendly catalyst is provided for the synthesis of biodiesel from waste oils with high acid value.

Catalysts derived from waste slag for transesterification

MgO-CaO/SiO2 solid catalysts derived from waste slag （WS） of metal magnesium plant were prepared. The catalytic performances were evaluated in the transesterification of rapeseed oil with methanol to biodiesel in a 500 mL three-necked reactor under atmospheric pressure. The basic strengh of the catalyst reached 22.0 measured by indicators accroding to Hammett scale. The results show that the MgO-CaO/SiO2 is an excellent catalyst for transesterification, and the conversion of rapeseed oil reach 98% under the optimum condition.

Esterification of Free Fatty Acids in Waste Cooking Oil by Heterogeneous Catalysts

Waste cooking oil(WCO) is becoming the most promising alternative feedstock to produce biodiesel due to its low cost in China. In this study, NKC-9 ion-exchange resin and H-beta zeolite were selected as heterogeneous catalysts in the WCO esterification process and their esterification characteristics were compared by orthogonal experiments. NKC-9 resin showed higher activity and achieved a higher final conversion compared with H-beta zeolite under the same reaction conditions. Reusability experiments showed that NKC-9 resin still exhibited high activity after 5 runs. The effects of the mole ratio of alcohol to oil, reaction time, reaction temperature and the catalyst dose were investigated by multifactor orthogonal analysis. The influence of the free fatty acid(FFA) content was also investigated, and the result showed that the esterification rate could be as high as 98.4% when the FFA content was 6.3wt%.

Physico-chemical structure evolution characteristics of coal char during gasification in the presence of iron-based waste catalyst

The present study aims to explore the physico-chemical structure evolution characteristic during Yangchangwan bituminous coal(YCW)gasification in the presence of iron-based waste catalyst(IWC).The catalytic gasification reactivity of YCW was measured by thermogravimetric analyzer.Scanning electron microscope–energy dispersive system,nitrogen adsorption analyzer and laser Raman spectroscopy were employed to analyze the char physico-chemical properties.The results show that the optimal IWC loading ratio was 5 wt%at 1000°C.The distribution of IWC on char was uneven and Fe catalyst concentrated on the surface of some chars.The specific surface area of YCW gasified semi-char decreased significantly with the increase of gasification time.i.e.,the specific surface area reduced from 382 m2/g(0 min)to 192 m2/g(3 min),meanwhile,the number of micropores and mesopores decreased sharply at the late gasification stage.The carbon microcrystalline structure of YCW gasified semi-char was gradually destroyed with the increase of gasification time,and the microcrystalline structure with small size was gradually generated,resulting in the decreasing order degree of carbon microcrystalline structure.IWC can catalyze YCW gasification which could provide theoretical guidance for industrial solid waste recycling.

Influence of coke rate on thermal treatment of waste selective catalytic reduction(SCR)catalyst during iron ore sintering

Waste selective catalytic reduction(SCR)catalyst as a hazardous waste has a significant impact on the environment and human health.In present study,a novel technology for thermal treatment of waste SCR catalyst was proposed by adding it to sinter mix for iron ore sintering.The influences of coke rate on the flame front propagation,sinter microstructure,and sinter quality during sintering co-processing the waste SCR catalyst process were studied.In situ tests results indicated the maximum sintering bed temperature increased at higher coke rate,indicating more liquid phase generated and higher airflow resistance.The sintering time was longer and the calculated flame front speed dropped at higher coke rate.Sinter microstructure results found the coalescence and reshaping of bubbles were more fully with increasing coke rate.The porosity dropped from 35.28%to 25.66%,the pore average diameter of large pores decreased from 383.76μm to 311.43μm.With increasing coke rate,the sinter indexes of tumbler index,productivity,and yield,increased from 33.2%,9.2 t·m^(-2)·d^(-1),28.9%to 58.0%,36.0 t·m^(-2)·d^(-1),68.9%,respectively.Finally,a comprehensive index was introduced to systematically assess the influence of coke rate on sinter quality,which rose from 100 to 200 when coke rate was increased from 3.5%(mass)to 5.5%(mass).

Photocatalytic Denitrogenation over Modified Waste FCC Catalyst

The strontium modified waste FCC catalyst was prepared by magnetic stirring method and characterized by Xray diffractometry(XRD),UV-Vis diffuse reflectance spectrometry(DRS),X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy(SEM).Meanwhile,its photocatalytic denitrogenation performance was evaluated in terms of its ability to degrade the N-containing simulation oil under visible light.A mixture of strontium nitrate solution(with a concentration of 0.5 mol/L)and waste FCC catalyst was calcined at 400℃for 5 h prior to taking part in the photocatalytic denitrogenation reaction.The test results showed that the photocatalytic degradation rate of pyridine contained in simulation oil in the presence of the strontium modified FCC catalyst could reach 92.0% under visible light irradiation for 2.5 h.

Influence of Al2O3 and TiO2 supports on catalytic performance of Ni and Co catalysts for gasification of glycerol waste

Since the constant increase in petroleum price, use of glycerol waste, which is a byproduct from biodiesel production, as a partial replacement for fossil fuels via thermochemical conversion waste to energy processes is more practical. Gasification reaction has attracted a lot of interest by producing syngas rich in CO and H2. This syngas can be converted to clean liquid fuels, such as methanol and Fischer-Tropsch oil. Nickel and Cobalt catalyst was widely used in steam reforming reaction. ethanol etc. The aim of this work is to prepare and characterize 5.0 and 10.0%wt of Ni and Co catalysts using the impregnation method on various supporters, such as alumina and titanium oxide （TiO2） and to evaluate their catalytic performance. The specific surface area of developed catalysts was measured. X-ray diffraction （XRD） was applied to determine phase and crystallized size of the catalysts. Examination of the morphology. elemental composition and distribution of metal on the catalysts support were carried out using scanning electron microscopy （SEMi and energy dispersion spectroscopy （EDS） and x-ray mapping. The catalytic performance of prepared catalysts was test at 700 and 900℃ temperature of reaction. 1.87% O2. The result showed that the synthesized nickel and cobalt catalysts via impregnation method using Al2O3 and TiO2 as the catalyst support were suitable for glycerol conversion.

Cobalt Recovery from Waste Catalysts (Petroleum Refining Industry from Gujarat)

A hydrometallurgical process has been developed for cobalt recovery from a waste catalyst (petroleum refining industry). This waste catalyst containing about 2.18 weight % of Co, is highly contaminated by Mg, Al, Si, Ca, Fe, Ni, Cu, Zn, Mo. The major steps are: (I) The spent catalyst is roasted with flux material in an electrical furnace at very high temperature (700?C) for a specific duration. (II) The roasted sample is leached with sulphuric acid to bring the metal contents into solution form. (III) For separating cobalt values from the leach solution, the solution pH is raised by NaOH addition, where all cobalt content is precipitated at a pH of about 12. (IV) This cobalt hydroxide precipitate is filtered and dissolved in minimum amount of sulphuric acid to get cobalt sulphate solution which is used as the electrolyte for the electrolytic recovery of cobalt. For optimizing various parameters like (1) H2SO4 concentration;(2) Duration;(3) Cobalt concentration;(4) Current density;(5) Temperature;(6) Stirring etc., The particle surface morphology and deposited layers have been characterized by scanning electron microscopy (SEM). A compact metallic deposit containing 70% cobalt was obtained.

Preparation and performance of rare earth Zr catalyst for reforming waste plastics cracking product

The rare earth Zr catalyst, whose carrier was Al 2O 3, was prepared by co-precipitation with Zr(NO 3) 2, Al(NO 3) 3, and(NH 2) 2CO as the raw materials. The obtained catalyst was used to reform the waste plastic cracking product. As the Zr content in the catalyst increases, the yields of gasoline, gas, and the rate of carbon deposition increase, but the yields of diesel and heavy oil decrease. The optimum Zr content of the catalyst is 5%. At 290 ℃, with this most suitable catalyst, the yield of liquid fuel oil is the highest, about 86.10%, and research octance number(RON) of the gasoline is 92.15.

Rapid chemical recycling of waste polyester plastics catalyzed by recyclable catalyst

Waste plastics are serious environmental threats due to their low degradability and low recycling rate.Rapid and efficient waste plastics recycling technologies are urgently demanded for a sustainable future.Herein,we report a rapid,closed-loop,and streamlined process to convert polyesters such as poly(ethylene terephthalate)(PET)back to its purified monomers.Using trifluoromethanesulfonic acid or metal triflates as the recyclable catalyst,polyesters such as PET can be completely depolymerized by simple carboxylic acids within 1 h.By coupling this acidolysis with a subsequent hydrogenolysis process,the consumed carboxylic acid was recovered and the closed-loop of PET depolymerization could be established.All catalysts and depolymerization agents are fully recycled while only PET and hydrogen are consumed.

Pathways for Sustainable Utilization of Waste Chicken Eggshell

Chicken eggshell is one of the most common wastes generated from households,restaurants and other food processing outlets.Waste Chicken Eggshells(WCES)also constitutes an environmental nuisance and ends up discarded at dumping site with no consideration of further usage.The main constituent of WCES is calcium carbonate from which calcium or calcium oxide can be extracted for various applications.This current effort reviews recently published literature on the diverse applications of WCES.The considered utilization avenues include catalysts for biofuel production,construction industry,wastewater purification,industrial sector,food industry,medical,and agricultural applications.The specific areas of application apart from the transesterification reactions include cement additives and replacement in concrete,asphalt binder,adsorbent of metals and dyes,production of hydroxyapatite,food supplement and fortification,dentistry,therapeutics,bone formation,drug delivery,poultry feeds as well as organic fertilizer.For most of the identified applications,the WCES is subjected to pretreatment and other modification techniques before utilization.The conversion of WCES to valuable products is a cost-effective,safe,environmentally friendly,non-toxic and viable means of waste disposal and utilization.More investigations are needed to further explore the benefits derivable from this bioresource.

Production of Bio-Calcium Oxide Derived from Hatchery Eggshell Waste Using an Industrial-Scale Car Bottom Furnace

The valorization of eggshell waste as bio-calcium oxide is crucial for pollution prevention and supporting sustainable development.There are several reports on the thermal conversion of eggshell waste to calcium oxide for the partial or complete substitution of natural lime applications.However,this paper reports the thermal decomposition of large amounts of hatchery eggshell waste on an industrial-scale car bottom furnace for the first time.The hatchery eggshell waste was sundried and placed into five stacked trays in the car bottom furnace.The calcination of the eggshell waste was conducted at 900℃ for 3 and 4 h under an atmosphere of air.Both the physical and chemical properties of the eggshell samples and the bio-quicklime products were carefully examined by TGA,SEM,XRD,FTIR,and XRF.The results demonstrate that the purity of calcium oxide in the quicklime products increased from 79%to 87%upon increasing the calcination time from 3 to 4 h.However,the color of the calcined eggshell samples at the surface of the pile was white while the color of the product beneath the surface was black or dark gray.The purity of the calcium oxide of both the black and white calcined samples was 76.4%and 91.5%,respectively.These results indicate the limited efficacy of the car bottom furnace for thermal decomposition of the large amount of eggshell waste to calcium oxide.Additionally,the production cost of bio-calcium oxide is approximately twice the cost of industrial grade lime.For further industrial applications,the furnace should contain the mixing equipment for improving the thermal decomposition of the large pile of eggshell waste.Furthermore,the oil burner system may be used in order to reduce fuel costs.

Commercial Application of Technology for Catalytic Combustion of Waste Gases from Wastewater Treatment System in Petrochemical Enterprises

The catalytic combustion technology for treating waste gases exiting from wastewater treatment system and oil separators in petrochemical enterprises was introduced in this article. Commercial application of this technology showed that the process ＂desulfurization and total hydrocarbon concentration homogenizationcatalytic combustion＂ and the associated WSH-1 combustion catalyst were suitable for treating volatile organic gases emitted from the oil separators, floatation tanks, inlet water-collecting well, waste oil tanks, etc. The commercial unit was equipped with an advanced auto-control system, featuring a simple operation and low energy consumption with good treatment effect. The purified gases could meet the national emission standard.