Catalytic Reaction of Ethanol into Light Olefins Over 2wt%CuO/HZSM-5

There was increasing in the international needing for fossil fuel, which is formed from nonrenewable materials such as crude oil. Bio-ethanol considered one of the materials that can be produced from renewable sources like the fermentation of sugar cane. 2wt% CuO doped HZSM-5 has been modified by the impregnation method. All experimental runs have conducted at 500 °C, 1 atmosphere pressure and WHSV 3.5 h-1 in a fixed bed reactor. Catalyst, which modified in this work, was analyzed by SEM and XRD as well as TGA experiment. The analysis hydrocarbons products have done by gas chromatographs provided with flame ionization detector (FID) and thermal conductivity detector (TCD). It has been studied CuO doped HZSM-5 catalyst gives higher ethanol conversion and yield especially light olefins as compared to HZSM-5 parent catalyst. In addition, reduces the coke formation over HZSM-5, therefore, enhanced the life of HZSM-5 catalyst. HZSM-5, ethanol to hydrocarbons, Catalyst, coke, deactivatio

Development of a methanol to hydrocarbons process over zeolite coatings in a microstructured reactor

In this work, the hydrothermal synthesis of ZSM-5 and its coating with controllable crystal size and Si/Al ratio has been performed. The obtained catalysts have been studied in the methanol to hydrocarbon (MTH) reaction. This reaction is the last step in an integrated fuel processor for the conversion of bio resources to liquid fuels. The development of ZSM-5 coatings has been supported by advanced characterization and testing of catalysts for the determination of property/performance relationships. An optimal synthesis time of 72 h was found to provide the highest crystallinity of ZSM-5 coatings. The larger crystal size of ZSM-5 coatings leads to a higher selectivity towards gasoline (C8-11) hydrocarbons. The selectivity towards the gasoline fraction over ZSM-5 coatings with a thickness of 14 μm was similar to that of an industrial ZSM-5 catalyst, however the yield of the undesirable aromatics by-products was reduced by half due to shorter diffusion pathways in thin catalyst layers. In an attempt to improve the yield of the C8-11 hydrocarbons, two post-synthesis modifications have been performed: Ca ion-exchange and desilication by alkaline treatment. The maximum gasoline selectivity over Ca-H-ZSM-5 was observed at a Ca/H ratio of 0.1 while the longest lifetime in the reaction was observed at the ratio of 0.2. Mesoporosity has been introduced into microporous ZSM-5 catalysts. The obtained meso-microporous ZSM-5 coating show 3 times lifetime and 2.7 times selectivity towards C8-11 hydrocarbon fraction than microporous coating in the MTH reaction. Lumped kinetics of MTH reaction over H-ZSM-5 were used to design a microstructured reactor/heat-exchanger (MRHE) with reaction channels coated with the ZSM-5 catalyst. 2D and 3D convection and conduction heat transfer models coupled with the MTH reaction kinetics were employed to investigate temperature distribution in the MRHE. The effect of the dimension of the microreactor/ heat-exchanger and flow condition on the temperature field has been studied. The 2D model under-predicts the magnitude of temperature gradient. The optimised reactor configuration shows a temperature gradient of 21 K in the reaction channels

Proceso catalítico de transformación de dimetil éter en olefinas (DTO)

325 p.Se ha estudiado la transformación catalítica de dimetil éter (DME) sobre catalizadores ácidos, para obtener selectivamente olefinas ligeras (proceso DTO), comparando catalizadores, determinando el efecto de las condiciones de operación y estableciendo un modelo cinético adecuado para simular el proceso DTO en un amplio intervalo de condiciones. El interés del proceso DTO está sustentado en la creciente implantación industrial de la síntesis de DME, sustituyendo a la síntesis de metanol, desde fuentes alternativas al petróleo (carbón, gas natural, biomasa).Los catalizadores estudiados se han preparado por aglomeración de funciones ácidas de diferente acidez y selectividad de forma: i) dos silicoaluminofosfatos (SAPO-18 y SAPO-34); ii) tres zeolitas HZSM-5 comerciales con diferente relación SiO2/Al2O3 (30, 80 y 280); iii) dos zeolitas HZSM-5 comerciales modificadas mediante impregnación con P y K.Los experimentos cinéticos se han realizado en un equipo automatizado de reacción, que dispone de un reactor de lecho fijo isotermo, acoplado a un micro-cromatógrafo de gases para el análisis en continuo de los productos de reacción. La comparación del comportamiento cinético de los catalizadores y su posterior discriminación, se han realizado atendiendo a los criterios de actividad, rendimiento y selectividad de olefinas ligeras, y estabilidad con el tiempo.Se han comprobado dos grandes diferencias con la transformación de metanol en olefinas (proceso MTO): 1) el mecanismo de pool de hidrocarburos transcurre más rápidamente, por la formación directa de propileno desde el DME; 2) la co-alimentación de H2O tiene mayor efecto de atenuación del mecanismo de reacción y de la deposición de coque. En consecuencia, el proceso DTO requiere un catalizador con menos acidez y condiciones de reacción (temperatura y tiempo espacial) menos severas que el proceso MTO. Un catalizador de zeolita HZSM-5 con relación SiO2/Al2O3 = 280 aglomerado con boehmita resulta estable y permite obtener un rendimiento de olefinas ligeras del 46-47 % (propileno del 16-18 %) a 375 ºC y un tiempo espacial de 3-4 gcat h molC-1.El modelo cinético del proceso DTO se ha abordado en dos etapas: i) determinando el modelo cinético de lumps a tiempo cero, con los datos del estudio paramétrico para tiempo de reacción cero (catalizador fresco), y ii) determinando un modelo global, que integra una ecuación cinética de desactivación por coque, la cual se ha obtenido a partir de los datos de evolución con el tiempo de la concentración de los componentes de la reacción. Este modelo permite simular el proceso DTO en el intervalo de 300-400 ºC y para las alimentaciones de DME puro y diluido con metanol y H2O, prediciendo la evolución con el tiempo de los diferentes lumps de productos y de cada una de las olefinas

Pyrolysis of Napier grass to bio-oil and catalytic upgrading to high grade bio-fuel

Biomass is one of the renewable energy resources that has carbon in its building blocks that can be processed into liquid fuel. Napier grass biomass is a herbaceous lignocellulosic material with potentials of high biomass yield. Utilization of Napier grass for bio-oil production via pyrolysis is very limited. Bio-oil generally has poor physicochemical properties such as low pH value, high water content, poor chemical and thermal stabilities which makes it unsuitable for direct use as fuel and therefore requires further processing. Upgrading of bio-oil to liquid fuel is still at early stage of research. Several studies are being carried out to upgrade bio-oil to transportation fuel. However, issues regarding reaction mechanisms and catalyst deactivation amongst others remain a challenge. This thesis gives insights and understanding of conversion of Napier grass biomass to liquid biofuel. The material was assessed as received and characterized using standard techniques. Pyrolysis was conducted in a fixed bed reactor and effect of pyrolysis temperature, nitrogen flow rate and heating rate on product distribution and characteristics were investigated collectively and pyrolysis products characterized. Effects of different aqueous pre-treatments on the pyrolysis product distribution and characteristics was evaluated. Subsequently, in-situ catalytic and non-catalytic, and ex-situ catalytic upgrading of bio-oil derived from Napier grass using Zeolite based catalysts (microporous and mesoporous) were investigated. Upgraded bio-oil was further fractionated in a micro-laboratory distillation apparatus. The experimental results showed that high bio-oil yield up to 51 wt% can be obtained from intermediate pyrolysis of Napier grass at 600 oC, 50 oC/min and 5 L/min nitrogen flow in a fixed bed reactor. The bio-oil collected was a two-phase liquid, organic (16 wt%) and aqueous (35 wt%) phase. The organic phase consists mainly of various benzene derivatives and hydrocarbons while the aqueous phase was predominantly water, acids, ketones, aldehydes and some phenolics and other water-soluble organics. Non-condensable gas (29 wt%) was made-up of methane, hydrogen, carbon monoxide and carbon dioxide with high hydrogen/carbon monoxide ratio. Bio-char (20 wt%) was a porous carbonaceous material, rich in mineral elements. Aqueous pre-treatment of Napier grass with deionized water at severity factor of 0.9 reduced ash content by 64 wt% and produced bio-oil with 71 % reduction in acid and ketones. Performance of mesoporous zeolites during both in-situ and ex-situ upgrading outweighed that of microporous zeolite, producing less solid and highly deoxygenated organic bio-oil rich in alkanes and monoaromatic hydrocarbons. The Upgraded bio-oil produced 38 wt% light fraction, 48 wt% middle distillate and 7.0wt% bottom product. This study demonstrated that bio-oil derived from Napier grass can be transformed to that high-grade bio-oil via catalytic upgrading over hierarchical mesoporous zeolite

Pyrolysis of Napier grass to bio-oil and catalytic upgrading to high grade bio-fuel

Biomass is one of the renewable energy resources that has carbon in its building blocks that can be processed into liquid fuel. Napier grass biomass is a herbaceous lignocellulosic material with potentials of high biomass yield. Utilization of Napier grass for bio-oil production via pyrolysis is very limited. Bio-oil generally has poor physicochemical properties such as low pH value, high water content, poor chemical and thermal stabilities which makes it unsuitable for direct use as fuel and therefore requires further processing. Upgrading of bio-oil to liquid fuel is still at early stage of research. Several studies are being carried out to upgrade bio-oil to transportation fuel. However, issues regarding reaction mechanisms and catalyst deactivation amongst others remain a challenge. This thesis gives insights and understanding of conversion of Napier grass biomass to liquid biofuel. The material was assessed as received and characterized using standard techniques. Pyrolysis was conducted in a fixed bed reactor and effect of pyrolysis temperature, nitrogen flow rate and heating rate on product distribution and characteristics were investigated collectively and pyrolysis products characterized. Effects of different aqueous pre-treatments on the pyrolysis product distribution and characteristics was evaluated. Subsequently, in-situ catalytic and non-catalytic, and ex-situ catalytic upgrading of bio-oil derived from Napier grass using Zeolite based catalysts (microporous and mesoporous) were investigated. Upgraded bio-oil was further fractionated in a micro-laboratory distillation apparatus. The experimental results showed that high bio-oil yield up to 51 wt% can be obtained from intermediate pyrolysis of Napier grass at 600 oC, 50 oC/min and 5 L/min nitrogen flow in a fixed bed reactor. The bio-oil collected was a two-phase liquid, organic (16 wt%) and aqueous (35 wt%) phase. The organic phase consists mainly of various benzene derivatives and hydrocarbons while the aqueous phase was predominantly water, acids, ketones, aldehydes and some phenolics and other water-soluble organics. Non-condensable gas (29 wt%) was made-up of methane, hydrogen, carbon monoxide and carbon dioxide with high hydrogen/carbon monoxide ratio. Bio-char (20 wt%) was a porous carbonaceous material, rich in mineral elements. Aqueous pre-treatment of Napier grass with deionized water at severity factor of 0.9 reduced ash content by 64 wt% and produced bio-oil with 71 % reduction in acid and ketones. Performance of mesoporous zeolites during both in-situ and ex-situ upgrading outweighed that of microporous zeolite, producing less solid and highly deoxygenated organic bio-oil rich in alkanes and monoaromatic hydrocarbons. The Upgraded bio-oil produced 38 wt% light fraction, 48 wt% middle distillate and 7.0wt% bottom product. This study demonstrated that bio-oil derived from Napier grass can be transformed to that high-grade bio-oil via catalytic upgrading over hierarchical mesoporous zeolite

Recent Perspectives in Pyrolysis Research

Recent Perspectives in Pyrolysis Research presents and discusses different routes of pyrolytic conversions. It contains exhaustive and comprehensive reports and studies of the use of pyrolysis for energy and materials production and waste management

Synthesis of carbon nanotubes supported iron catalysts for light olefins via Fischer-Tropsch synthesis

Light olefins including ethylene, propylene and butylene are the basics of many chemical products. As the demand for light olefins is dramatically increased and oil resources are limited, it becomes desirable to produce light olefins from other resources such as syngas. Syngas could be obtained from alternative feedstocks such as methane, coal, biomass, and plastic wastes. Fischer-Tropsch (FT) synthesis involves conversion of syngas to hydrocarbons. FT products at high temperatures are mainly gasoline and light olefins. In FT catalytic reaction, iron is preferred due to its low cost, high selectivity towards olefins and flexibility in terms of use for different ratio of H2 to CO in syngas feed. In this study, catalytic performance of iron catalyst was evaluated using molybdenum and potassium as promoters and carbon nanotubes (CNTs) as support. The study plan for this research was divided into four sub-objectives or phases. In the first phase, catalytic chemical vapor deposition (CCVD) method was applied to synthesize CNTs using Fe/CaCO3 and acetylene as catalyst and hydrocarbon source, respectively. Applying response surface methodology, the optimum operating conditions were determined in CVD reactor for maximal yield and purity of CNTs. The effects of reaction time (30–60 min), reaction temperature (700–800 °C), and loading of the catalyst (10–30 wt% Fe) were investigated. 20Fe/CNTs-synthesized, 20Fe/CNTs-commercial, and 20Fe/Al2O3 were analyzed in terms of physio-chemical properties and FTS catalytic performance. The catalytic performance of Fe-based catalysts was investigated using a fixed-bed reactor at 280 °C under 2.0 MPa. 20Fe/CNTs-synthesized exhibited a lower rate of water-gas-shift (WGS) reaction compared with 20Fe/CNTs-commercial, with C2-C4 selectivity of 23.6% which is slightly less than that of its commercial counterpart. After 120 h time-on-stream under steady state condition, the higher activity was maintained by the 20Fe/CNTs-synthesized catalyst compared to the 20Fe/CNTs-Commercial and 20Fe/Al2O3 catalysts. Electronic structural promoters such as K and Mo improve olefins’ selectivity and catalytic activity. Hence, in the second phase, CNTs synthesized by CCVD were used as support to obtain K- and/or Mo-promoted Fe/CNTs catalysts for light olefins’ production in FTS. A two-level full factorial design was applied for K- and/or Mo-promoted Fe/CNTs catalyst to investigate the effects of synthesis conditions including Mo/K mass ratio, ultrasonic time, and iron loading on light olefins’ yield. CO chemisorption and TEM revealed that molybdenum plays a significant role in metal dispersion, leaving structural defects on CNTs support. iii Additionally, H2-TPR confirmed that K as promoter facilitates reducibility of Fe/CNTs catalysts, which promoted CO conversion in FTS. Compared with the un-promoted Fe/CNTs catalysts, addition of molybdenum as a promoter increased light olefins' selectivity by 33.4%, while potassium led to an increase in CO conversion by 96.3%. The optimum formulation (0.5K5Mo10Fe/CNTs) obtained the olefins’ yield of 35.5%. In the third phase the kinetic study of FTS was performed over the optimum bimetallic promoted catalyst (0.5K5Mo10Fe/CNTs) in a fixed-bed reactor by collecting experimental data over a wide range of industrially relevant reaction conditions (P = 0.68–4.13 MPa, T = 270-290 °C, H2/CO = 1, GHSV = 2000 h-1). Based on the adsorption of carbon monoxide and hydrogen, twenty-two possible mechanisms for monomer formation during Fischer-Tropsch synthesis were proposed in accordance with the Langmuir-Hinshelwood-Hougen-Watson (LHHW) and Eley-Rideal (ER) adsorption theories. Kinetic parameters such as activation energy, adsorption enthalpies of H2 and CO were estimated to be 65.0, -13.0, and -54.0 kJ/mol, respectively. Based on the developed kinetic model, the effects of reaction temperature and pressure were assessed on FTS product distribution. In addition, the Anderson-Schulz-Flory model was applied to further assess the reliability of the best fit mechanistic model for a wide range of hydrocarbon products. In the fourth phase, techno-economic analysis (TEA) and life cycle assessment (LCA) of light olefin production in Fischer-Tropsch synthesis reaction were investigated via different scenarios. Data from a lab-scale experiment using the optimum bimetallic promoted catalyst (0.5K5Mo10Fe/CNTs) were used to simulate a plant to produce 1 kg of ethylene/h. The economic feasibility of light olefins production was estimated based on a comprehensive cash flow analysis. The net rate of return (NRR) was calculated to 5.6%, 7.4%, and 18.2% for the base scenario (scenario 1), scenario 2 with wastewater treatment, and scenario 3 with wastewater treatment-separation unit, respectively, which means the project is profitable from an economic perspective. The GHG emissions performance was measured as 77.5 g CO2-eq per MJ ethylene confirming the significant GHG emissions decrease compared to petroleum-based fuels production (3686 g CO2-eq per MJ ethylene)

Intelligent Energy-Savings and Process Improvement Strategies in Energy-Intensive Industries

S tím, jak se neustále vyvíjejí nové technologie pro energeticky náročná průmyslová odvětví, stávající zařízení postupně zaostávají v efektivitě a produktivitě. Tvrdá konkurence na trhu a legislativa v oblasti životního prostředí nutí tato tradiční zařízení k ukončení provozu a k odstavení. Zlepšování procesu a projekty modernizace jsou zásadní v udržování provozních výkonů těchto zařízení. Současné přístupy pro zlepšování procesů jsou hlavně: integrace procesů, optimalizace procesů a intenzifikace procesů. Obecně se v těchto oblastech využívá matematické optimalizace, zkušeností řešitele a provozní heuristiky. Tyto přístupy slouží jako základ pro zlepšování procesů. Avšak, jejich výkon lze dále zlepšit pomocí moderní výpočtové inteligence. Účelem této práce je tudíž aplikace pokročilých technik umělé inteligence a strojového učení za účelem zlepšování procesů v energeticky náročných průmyslových procesech. V této práci je využit přístup, který řeší tento problém simulací průmyslových systémů a přispívá následujícím: (i)Aplikace techniky strojového učení, která zahrnuje jednorázové učení a neuro-evoluci pro modelování a optimalizaci jednotlivých jednotek na základě dat. (ii) Aplikace redukce dimenze (např. Analýza hlavních komponent, autoendkodér) pro vícekriteriální optimalizaci procesu s více jednotkami. (iii) Návrh nového nástroje pro analýzu problematických částí systému za účelem jejich odstranění (bottleneck tree analysis – BOTA). Bylo také navrženo rozšíření nástroje, které umožňuje řešit vícerozměrné problémy pomocí přístupu založeného na datech. (iv) Prokázání účinnosti simulací Monte-Carlo, neuronové sítě a rozhodovacích stromů pro rozhodování při integraci nové technologie procesu do stávajících procesů. (v) Porovnání techniky HTM (Hierarchical Temporal Memory) a duální optimalizace s několika prediktivními nástroji pro podporu managementu provozu v reálném čase. (vi) Implementace umělé neuronové sítě v rámci rozhraní pro konvenční procesní graf (P-graf). (vii) Zdůraznění budoucnosti umělé inteligence a procesního inženýrství v biosystémech prostřednictvím komerčně založeného paradigmatu multi-omics.Zlepšení průmyslových procesů, Model založený na datech, Optimalizace procesu, Strojové učení, Průmyslové systémy, Energeticky náročná průmyslová odvětví, Umělá inteligence.

Book of abstracts of the 10th International Chemical and Biological Engineering Conference: CHEMPOR 2008

This book contains the extended abstracts presented at the 10th International Chemical and Biological Engineering Conference - CHEMPOR 2008, held in Braga, Portugal, over 3 days, from the 4th to the 6th of September, 2008. Previous editions took place in Lisboa (1975, 1889, 1998), Braga (1978), Póvoa de Varzim (1981), Coimbra (1985, 2005), Porto (1993), and Aveiro (2001). The conference was jointly organized by the University of Minho, “Ordem dos Engenheiros”, and the IBB - Institute for Biotechnology and Bioengineering with the usual support of the “Sociedade Portuguesa de Química” and, by the first time, of the “Sociedade Portuguesa de Biotecnologia”. Thirty years elapsed since CHEMPOR was held at the University of Minho, organized by T.R. Bott, D. Allen, A. Bridgwater, J.J.B. Romero, L.J.S. Soares and J.D.R.S. Pinheiro. We are fortunate to have Profs. Bott, Soares and Pinheiro in the Honor Committee of this 10th edition, under the high Patronage of his Excellency the President of the Portuguese Republic, Prof. Aníbal Cavaco Silva. The opening ceremony will confer Prof. Bott with a “Long Term Achievement” award acknowledging the important contribution Prof. Bott brought along more than 30 years to the development of the Chemical Engineering science, to the launch of CHEMPOR series and specially to the University of Minho. Prof. Bott’s inaugural lecture will address the importance of effective energy management in processing operations, particularly in the effectiveness of heat recovery and the associated reduction in greenhouse gas emission from combustion processes. The CHEMPOR series traditionally brings together both young and established researchers and end users to discuss recent developments in different areas of Chemical Engineering. The scope of this edition is broadening out by including the Biological Engineering research. One of the major core areas of the conference program is life quality, due to the importance that Chemical and Biological Engineering plays in this area. “Integration of Life Sciences & Engineering” and “Sustainable Process-Product Development through Green Chemistry” are two of the leading themes with papers addressing such important issues. This is complemented with additional leading themes including “Advancing the Chemical and Biological Engineering Fundamentals”, “Multi-Scale and/or Multi-Disciplinary Approach to Process-Product Innovation”, “Systematic Methods and Tools for Managing the Complexity”, and “Educating Chemical and Biological Engineers for Coming Challenges” which define the extended abstracts arrangements along this book. A total of 516 extended abstracts are included in the book, consisting of 7 invited lecturers, 15 keynote, 105 short oral presentations given in 5 parallel sessions, along with 6 slots for viewing 389 poster presentations. Full papers are jointly included in the companion Proceedings in CD-ROM. All papers have been reviewed and we are grateful to the members of scientific and organizing committees for their evaluations. It was an intensive task since 610 submitted abstracts from 45 countries were received. It has been an honor for us to contribute to setting up CHEMPOR 2008 during almost two years. We wish to thank the authors who have contributed to yield a high scientific standard to the program. We are thankful to the sponsors who have contributed decisively to this event. We also extend our gratefulness to all those who, through their dedicated efforts, have assisted us in this task. On behalf of the Scientific and Organizing Committees we wish you that together with an interesting reading, the scientific program and the social moments organized will be memorable for all.Fundação para a Ciência e a Tecnologia (FCT