scholarly journals Process Simulation and Economic Evaluation of Bio-Oil Two-Stage Hydrogenation Production

2019 ◽  
Vol 9 (4) ◽  
pp. 693
Author(s):  
Xiaoyuechuan Ma ◽  
Shusheng Pang ◽  
Ruiqin Zhang ◽  
Qixiang Xu
Keyword(s):  
Process Simulation ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Fuel Oil ◽  
Coke Deposition ◽  
Two Stage ◽  
Bio Oil ◽  
Demonstration Plant ◽  
Two Stages ◽  
Optimal Reaction

Bio-oil hydrogenation upgrading process is a method that can convert crude bio-oil into high-quality bio-fuel oil, which includes two stages of mild and deep hydrogenation. However, coking in the hydrogenation process is the key issue which negatively affects the catalyst activity and consequently the degree of hydrogenation in both stages. In this paper, an Aspen Plus process simulation model was developed for the two-stage bio-oil hydrogenation demonstration plant which was used to evaluate the effect of catalyst coking on the bio-oil upgrading process and the economic performance of the process. The model was also used to investigate the effect of catalyst deactivation caused by coke deposition in the mild stage. Three reaction temperatures in the mild stage (250 °C, 280 °C, and 300 °C) were considered. The simulation results show that 45% yield of final product is obtained at the optimal reaction condition which is 280 °C for the mild stage and 400 °C for the deep stage. Economic analysis shows that the capital cost of industrial production is $15.2 million for a bio-oil upgrading plant at a scale of 107 thousand tons per year. The operating costs are predicted to be $1024.27 per ton of final product.

scholarly journals Mechanistic Insights into Hydrodeoxygenation of Acetone over Mo/HZSM-5 Bifunctional Catalyst for the Production of Hydrocarbons

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 53
Author(s):  
Kai Miao ◽  
Tan Li ◽  
Jing Su ◽  
Cong Wang ◽  
Kaige Wang
Keyword(s):  
Hydrogen Pressure ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Coke Formation ◽  
Bifunctional Catalyst ◽  
Acid Sites ◽  
Coke Deposition ◽  
Enhanced Production ◽  
Bio Oil ◽  
Catalytic Hydropyrolysis

Catalytic hydropyrolysis via the introduction of external hydrogen into catalytic pyrolysis process using hydrodeoxygenation catalysts is one of the major approaches of bio-oil upgrading. In this study, hydrodeoxygenation of acetone over Mo/HZSM-5 and HZSM-5 were investigated with focus on the influence of hydrogen pressure and catalyst deactivation. It is found that doped MoO3 could prolong the catalyst activity due to the suppression of coke formation. The influence of hydrogen pressure on catalytic HDO of acetone was further studied. Hydrogen pressure of 30 bar effectively prolonged catalyst activity while decreased the coke deposition over catalyst. The coke formation over the HZSM-5 and Mo/HZSM-5 under 30 bar hydrogen pressure decreased 66% and 83%, respectively, compared to that under atmospheric hydrogen pressure. Compared to the test with the HZSM-5, 35% higher yield of aliphatics and 60% lower coke were obtained from the Mo/HZSM-5 under 30 bar hydrogen pressure. Characterization of the spent Mo/HZSM-5 catalyst revealed the deactivation was mainly due to the carbon deposition blocking the micropores and Bronsted acid sites. Mo/HZSM-5 was proved to be potentially enhanced production of hydrocarbons.

Integration of Thermal Treatment and Catalytic Transformation for Upgrading Biomass Pyrolysis Oil

2007 ◽  
Vol 5 (1) ◽  
Author(s):  
Beatriz Valle ◽  
Ana Guadalupe Gayubo ◽  
Alaitz Atutxa ◽  
Ainhoa Alonso ◽  
Javier Bilbao
Keyword(s):  
Thermal Treatment ◽  
Thermal Degradation ◽  
Fluidized Bed ◽  
Catalyst Deactivation ◽  
Fluidized Bed Reactor ◽  
Coke Deposition ◽  
Catalytic Transformation ◽  
Pyrolysis Oil ◽  
Bio Oil ◽  
Oil Components

The upgrading of bio-oil by catalytic transformation upon acidic catalysts is aimed at adapting its composition to that of conventional fuel, or at obtaining petrochemical raw materials, such as olefins and aromatics. A further alternative of growing interest for bio-oil upgrading is catalytic reforming for obtaining H2. The viability of any of these alternatives requires minimizing both the plugging problems that arise in the reactor when the bio-oil is fed and the rapid deactivation of the catalyst, which are associated with the thermal degradation of the lignocellulosic components. In this paper, the catalytic transformation of bio-oil (obtained by fast pyrolysis of vegetable biomass) in a fluidized bed reactor upon a Ni-HZSM-5 zeolite catalyst has been studied, and special attention has been paid to the design of the feed preheating zone. Operation in a single-unit (U-shaped steel tube) for the thermal treatment of the bio-oil (in the downward zone of the U-tube) and its catalytic transformation (in a fluidized bed located in the upward zone of the U-tube) has been compared with operation in a two-unit system, where both steps are carried out in separate units connected through a thermostated line (U-shaped tube for thermal treatment, followed by a fluidized bed reactor for catalytic transformation). It has been proven that a separate step of thermal treatment prior to the catalytic transformation notably improves the global process of bio-oil upgrading. Firstly, it contributes to minimizing coke deposition on the acidic catalyst, mainly the deposition of "thermal" coke (which is associated with the thermal degradation of the bio-oil components at high temperatures), leading to an important attenuation of catalyst deactivation. Secondly, the bio-oil components degraded in the thermal treatment can subsequently be subjected to another upgrading treatment (by steam activation or pyrolysis) in order to obtain a high quality char, which involves upgrading the entire bio-oil.

Modelling Catalyst Deactivation by External Coke Deposition during Fluid Catalytic Cracking

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Gladys Jiménez-García ◽  
Roberto Quintana-Solórzano ◽  
Ricardo Aguilar-López ◽  
Rafael Maya-Yescas
Keyword(s):  
Catalytic Cracking ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Effective Diffusivity ◽  
Fluid Catalytic Cracking ◽  
Coke Deposition ◽  
Negative Exponential Function ◽  
Operating Variables ◽  
Laboratory Reactor ◽  
Negative Exponential

Although the Fluid Catalytic Cracking (FCC) is an economic important process, simulation of its kinetics is rather empirical—mainly it is a consequence of the complex interactions among operating variables and the complex kinetics that take place. A crucial issue is the inevitable catalyst reversible deactivation, consequence of both, coke (by-product) deposition on the catalyst surface (external) and inside the catalytic zeolite (internal). In order to tackle this problem, two main proposals to evaluate deactivation rate by coking have been extensively applied, both use a probability distribution function called "the negative exponential function"—one of them uses the time that catalyst has been in the reacting stream (named Time-on-Stream), and the other is related to the coke amount on/inside the catalyst (denoted as Coke-on-Catalyst). These two deactivation models can be unified by tracking catalyst activity as function of the decrease on effective diffusivity due to pore occlusion (external) by coke—this situation leads to an increase of Thiele modules and consequently a decrease of the effectiveness factor of each reaction. This tracking of catalyst activity incorporates, implicitly, rates of reaction and transport phenomena taking place in the catalyst pores and is therefore phenomenological rather than statistical. In this work, the activity profiles predicted previously are reproduced at MAT laboratory reactor. The same approach is used to model an industrial riser and the results are in agreement with previous reports.

scholarly journals Stability of Li-LSX Zeolite in the Catalytic Pyrolysis of Non-Treated and Acid Pre-Treated Isochrysis sp. Microalgae

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 959 ◽  
Author(s):  
Nur Adilah Abd Rahman ◽  
Javier Fermoso ◽  
Aimaro Sanna
Keyword(s):  
Alkali Metals ◽  
Catalytic Pyrolysis ◽  
Zeolite Catalyst ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Zeolite Structure ◽  
Yield And Quality ◽  
Reducing Gas ◽  
Bio Oil ◽  
Pre Treatment

This paper investigates the use of Li-LSX-zeolite catalyst over three regeneration cycles in presence of non-treated and acid pre-treated Isochrysis sp. microalgae. The spent and regenerated catalysts were characterised by surface analysis, elemental analysis (EA), SEM-EDS, and XRD to correlate their properties with the bio-oil yield and quality. The acid pre-treatment removed alkali metals, reducing gas yield in favour of bio-oil, but, at the same time, led to catalyst deactivation by fouling. Differently, the non-treated microalgae resulted in a bio-oil enriched in C and H and depleted in O, compared to the pre-treated ones, denoting higher deoxygenation activity. After 3 pyrolysis/regeneration cycles, the analyses suggest that there are no major changes on catalyst using non-treated microalgae. Regeneration at 700 °C has been shown to be able to remove most of the coke without damaging the Li-LSX zeolite structure. In summary, Li-LSX zeolite was effective in maintaining deoxygenation activity over three cycles in the pyrolysis of non-treated Isochrysis microalgae, while the algae pre-treatment with sulphuric acid was detrimental on the catalyst activity.

scholarly journals Directed transforming of coke to active intermediates in methanol-to-olefins catalyst to boost light olefins selectivity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jibin Zhou ◽  
Mingbin Gao ◽  
Jinling Zhang ◽  
Wenjuan Liu ◽  
Tao Zhang ◽  
...  
Keyword(s):  
Density Functional ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Density Functional Theory Calculations ◽  
Steam Gasification ◽  
Coke Deposition ◽  
Light Olefins ◽  
Structured Illumination ◽  
Structured Illumination Microscopy ◽  
Light Olefins Selectivity

AbstractMethanol-to-olefins (MTO), the most important catalytic process producing ethylene and propylene from non-oil feedstocks (coal, natural gas, biomass, CO2, etc.), is hindered by rapid catalyst deactivation due to coke deposition. Common practice to recover catalyst activity, i.e. removing coke via air combustion or steam gasification, unavoidably eliminates the active hydrocarbon pool species (HCPs) favoring light olefins formation. Density functional theory calculations and structured illumination microscopy reveal that naphthalenic cations, active HCPs enhancing ethylene production, are highly stable within SAPO-34 zeolites at high temperature. Here, we demonstrate a strategy of directly transforming coke to naphthalenic species in SAPO-34 zeolites via steam cracking. Fluidized bed reactor-regenerator pilot experiments show that an unexpectedly high light olefins selectivity of 85% is achieved in MTO reaction with 88% valuable CO and H2 and negligible CO2 as byproducts from regeneration under industrial-alike continuous operations. This strategy significantly boosts the economics and sustainability of MTO process.

scholarly journals Bio-DEE Synthesis and Dehydrogenation Coupling of Bio-Ethanol to Bio-Butanol over Multicomponent Mixed Metal Oxide Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 660
Author(s):  
Izabela S. Pieta ◽  
Alicja Michalik ◽  
Elka Kraleva ◽  
Dusan Mrdenovic ◽  
Alicja Sek ◽  
...  
Keyword(s):  
Active Sites ◽  
Internal Combustion Engines ◽  
Mixed Oxides ◽  
Catalyst Activity ◽  
Product Distribution ◽  
Coke Deposition ◽  
Precipitation Method ◽  
Mixed Metal Oxide ◽  
Low Carbon ◽  
Municipal Solid Wastes

Within the Waste2Fuel project, innovative, high-performance, and cost-effective fuel production methods from municipal solid wastes (MSWs) are sought for application as energy carriers or direct drop-in fuels/chemicals in the near-future low-carbon power generation systems and internal combustion engines. Among the studied energy vectors, C1-C2 alcohols and ethers are mainly addressed. This study presents a potential bio-derived ethanol oxidative coupling in the gas phase in multicomponent systems derived from hydrotalcite-containing precursors. The reaction of alcohol coupling to ethers has great importance due to their uses in different fields. The samples have been synthesized by the co-precipitation method via layered double hydroxide (LDH) material synthesis, with a controlled pH, where the M(II)/M(III) ≈ 0.35. The chemical composition and topology of the sample surface play essential roles in catalyst activity and product distribution. The multiple redox couples Ni2+/Ni3+, Cr2+/Cr3+, Mn2+/Mn3+, and the oxygen-vacant sites were considered as the main active sites. The introduction of Cr (Cr3+/Cr4+) and Mn (Mn3+/Mn4+) into the crystal lattice could enhance the number of oxygen vacancies and affect the acid/base properties of derived mixed oxides, which are considered as crucial parameters for process selectivity towards bio-DEE and bio-butanol, preventing long CH chain formation and coke deposition at the same time.

BioSNG—process simulation and comparison with first results from a 1-MW demonstration plant

2011 ◽  
Vol 1 (2) ◽  
pp. 111-119 ◽  
Author(s):  
Barbara Rehling ◽  
Hermann Hofbauer ◽  
Reinhard Rauch ◽  
Christian Aichernig
Keyword(s):  
Process Simulation ◽  
First Results ◽  
Demonstration Plant

A novel two-stage method of plant seedlings classification based on deep learning

2021 ◽  
pp. 1-11
Author(s):  
Tianhong Dai ◽  
Shijie Cong ◽  
Jianping Huang ◽  
Yanwen Zhang ◽  
Xinwang Huang ◽  
...  
Keyword(s):  
Deep Learning ◽  
Learning Technology ◽  
Two Stage ◽  
Second Stage ◽  
Stage Classification ◽  
Different Types ◽  
Two Stages ◽  
Plant Seedlings

In agricultural production, weed removal is an important part of crop cultivation, but inevitably, other plants compete with crops for nutrients. Only by identifying and removing weeds can the quality of the harvest be guaranteed. Therefore, the distinction between weeds and crops is particularly important. Recently, deep learning technology has also been applied to the field of botany, and achieved good results. Convolutional neural networks are widely used in deep learning because of their excellent classification effects. The purpose of this article is to find a new method of plant seedling classification. This method includes two stages: image segmentation and image classification. The first stage is to use the improved U-Net to segment the dataset, and the second stage is to use six classification networks to classify the seedlings of the segmented dataset. The dataset used for the experiment contained 12 different types of plants, namely, 3 crops and 9 weeds. The model was evaluated by the multi-class statistical analysis of accuracy, recall, precision, and F1-score. The results show that the two-stage classification method combining the improved U-Net segmentation network and the classification network was more conducive to the classification of plant seedlings, and the classification accuracy reaches 97.7%.

scholarly journals Simple Method of Approximate Calculation of Statically Indeterminate Trusses

2019 ◽  
Vol 16 (06) ◽  
pp. 1840026 ◽  
Author(s):  
Janusz Rębielak
Keyword(s):  
Approximate Calculation ◽  
Computer Software ◽  
Two Stage ◽  
Simple Method ◽  
Two Stages

The paper presents principles of the simple method which makes possible approximate calculations of statically indeterminate truss systems in two stages. The two-stage method applies rules of other methods used for calculations of statically determinate trusses. In each of the two stages, there are considered statically determinate trusses, patterns of which are obtained as results of suitable withdrawing of appropriate members from the pattern of the basic statically indeterminate truss. There are presented results of calculations carried out for two cases of load for selected type of plane truss together with comparison of outcomes obtained by means of using appropriate computer software.

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