Coke formation and deactivation during catalytic reforming of biomass and waste pyrolysis products: A review

Ochoa, Aitor; Bilbao, Javier; Gayubo, Ana G.; Castaño, Pedro

doi:10.1016/j.rser.2019.109600

Cited by 289 publications

(150 citation statements)

References 356 publications

(529 reference statements)

Supporting

Mentioning

144

Contrasting

Order By: Relevance

“…Poisoning is due to the strong chemisorption of species on catalytic sites that block the catalytic activity. Catalysts regeneration is intimately related to the type of deactivation, which is the most used way to regenerate the reforming catalysts involves oxidative environments at high temperatures to burn off the coke [48]. Nickel-based catalysts that are deactivated by particle sintering can be successful regenerated by treatment with oxidative CO 2 atmosphere, as well as catalysts, deactivated by sulfur poisoning can be regenerated by steam/hydrogen stream treatment [49].…”

Section: Deactivation Studiesmentioning

confidence: 99%

A Short Review on Ni Based Catalysts and Related Engineering Issues for Methane Steam Reforming

2020

View full text Add to dashboard Cite

Hydrogen is an important raw material in chemical industries, and the steam reforming of light hydrocarbons (such as methane) is the most used process for its production. In this process, the use of a catalyst is mandatory and, if compared to precious metal-based catalysts, Ni-based catalysts assure an acceptable high activity and a lower cost. The aim of a distributed hydrogen production, for example, through an on-site type hydrogen station, is only reachable if a novel reforming system is developed, with some unique properties that are not present in the large-scale reforming system. These properties include, among the others, (i) daily startup and shutdown (DSS) operation ability, (ii) rapid response to load fluctuation, (iii) compactness of device, and (iv) excellent thermal exchange. In this sense, the catalyst has an important role. There is vast amount of information in the literature regarding the performance of catalysts in methane steam reforming. In this short review, an overview on the most recent advances in Ni based catalysts for methane steam reforming is given, also regarding the use of innovative structured catalysts.

show abstract

Section: Deactivation Studiesmentioning

confidence: 99%

A Short Review on Ni Based Catalysts and Related Engineering Issues for Methane Steam Reforming

2020

View full text Add to dashboard Cite

show abstract

“…Nickel/Al 2 O 3 catalysts have been used to produce hydrogen from waste plastics since this type of catalyst is commonly used for the commercial production of hydrogen from natural gas [9,19]. In addition, Al 2 O 3 is known to be chemically and physically stable with high mechanical strength properties [24]. Ni/zeolite catalysts, particularly Ni-ZSM-5 type catalysts have been investigated for the production of hydrogen from waste plastics [21,46,47] but fewer data are available for Ni/Y-zeolite which has a larger pore size and surface area than ZSM-5 catalysts.…”

Section: Effect Of Ni-catalyst Support Materials On the Co-pyrolysis-cmentioning

confidence: 99%

“…Ni/zeolite catalysts, particularly Ni-ZSM-5 type catalysts have been investigated for the production of hydrogen from waste plastics [21,46,47] but fewer data are available for Ni/Y-zeolite which has a larger pore size and surface area than ZSM-5 catalysts. The introduction of nickel into zeolites has been suggested to influence the surface acidity which in turn influences coke formation [46] and the mesoporosity and microporosity of zeolite also improve the dispersion of the nickel particles within the pores of the support [21,24]. Table 6 shows the product yield for different nickel catalyst support material, Ni/MCM-41, Ni/Al 2 O 3 , and Ni/Y-zeolite, in relation to the co-pyrolysis steam reforming of cellulose and plastics waste blends.…”

Section: Effect Of Ni-catalyst Support Materials On the Co-pyrolysis-cmentioning

confidence: 99%

“…The most common catalysts used for hydrogen production from biomass [22] and waste plastics [23] are nickel-based, reflecting the main type of catalyst used for commercial methane catalytic steam reforming [24]. Other transition metals investigated include Co, Fe, Cu, and also noble metal catalysts such as Pt, Pd, Rh, and Ru [9,24]. However, Ni-based catalysts, are preferred due to their lower cost and enhanced activity for breaking C─C, C─H, C─O, and O─H bonds and also for hydrogenation producing H atoms to form H 2 [9].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Co-pyrolysis–catalytic steam reforming of cellulose/lignin with polyethylene/polystyrene for the production of hydrogen

Akubo

Nahil

Williams

2020

Waste Dispos. Sustain. Energy

View full text Add to dashboard Cite

Co-pyrolysis of biomass biopolymers (lignin and cellulose) with plastic wastes (polyethylene and polystyrene) coupled with downstream catalytic steam reforming of the pyrolysis gases for the production of a hydrogen-rich syngas is reported. The catalyst used was 10 wt.% nickel supported on MCM-41. The influence of the process parameters of temperature and the steam flow rate was examined to optimize hydrogen and syngas production. The cellulose/plastic mixtures produced higher hydrogen yields compared with the lignin/plastic mixtures. However, the impact of raising the catalytic steam reforming temperature from 750 to 850 °C was more marked for lignin addition. For example, the hydrogen yield for cellulose/polyethylene at a catalyst temperature of 750 °C was 50.3 mmol g−1 and increased to 60.0 mmol g−1 at a catalyst temperature of 850 °C. However, for the lignin/polyethylene mixture, the hydrogen yield increased from 25.0 to 50.0 mmol g−1 representing a twofold increase in hydrogen yield. The greater influence on hydrogen and yield for the lignin/plastic mixtures compared to the cellulose/plastic mixtures is suggested to be due to the overlapping thermal degradation profiles of lignin and the polyethylene and polystyrene. The input of steam to the catalyst reactor produced catalytic steam reforming conditions and a marked increase in hydrogen yield. The influence of increased steam input to the process was greater for the lignin/plastic mixtures compared to the cellulose/plastic mixtures, again linked to the overlapping thermal degradation profiles of the lignin and the plastics. A comparison of the Ni/MCM-41 catalyst with Ni/Al2O3 and Ni/Y-zeolite-supported catalysts showed that the Ni/Al2O3 catalyst gave higher yields of hydrogen and syngas. Graphic abstract

show abstract

“…Deposition of carbon may result in direct encapsulation of active sites present on the catalyst's surface, formation of filamentous carbon, plugging of pores (which contributes to blocking the access of reagents to active sites located in the inner pores), and deterioration of catalyst structure. The mechanism of coke formation was previously described in extensive review and research articles [17,18]. Generally, the formation of two main forms of carbon deposit can be observed-encapsulating coke and filamentous coke.…”

Section: Introductionmentioning

confidence: 99%

Catalyst Stability—Bottleneck of Efficient Catalytic Pyrolysis

Grams

Ruppert

2021

Catalysts

View full text Add to dashboard Cite

The pyrolysis of lignocellulosic biomass is one of the most promising methods of alternative fuels production. However, due to the low selectivity of this process, the quality of the obtained bio-oil is usually not satisfactory and does not allow for its direct use as an engine fuel. Therefore, there is a need to apply catalysts able to upgrade the composition of the mixture of pyrolysis products. Unfortunately, despite the increase in the efficiency of the thermal decomposition of biomass, the catalysts undergo relatively fast deactivation and their stability can be considered a bottleneck of efficient pyrolysis of lignocellulosic feedstock. Therefore, solving the problem of catalyst stability is extremely important. Taking that into account, we presented, in this review, the most important reasons for catalyst deactivation, including coke formation, sintering, hydrothermal instability, and catalyst poisoning. Moreover, we discussed the progress in the development of methods leading to an increase in the stability of the catalysts of lignocellulosic biomass pyrolysis and strengthening their resistance to deactivation.

show abstract

Coke formation and deactivation during catalytic reforming of biomass and waste pyrolysis products: A review

Cited by 289 publications

References 356 publications

A Short Review on Ni Based Catalysts and Related Engineering Issues for Methane Steam Reforming

A Short Review on Ni Based Catalysts and Related Engineering Issues for Methane Steam Reforming

Co-pyrolysis–catalytic steam reforming of cellulose/lignin with polyethylene/polystyrene for the production of hydrogen

Catalyst Stability—Bottleneck of Efficient Catalytic Pyrolysis

Contact Info

Product

Resources

About