Wood pyrolisys using aspen plus simulation and industrially applicable model

Over the past decades, a great deal of experimental work has been carried out on the development of pyrolysis processes for wood and waste materials. Pyrolysis is an important phenomenon in thermal treatment of wood, therefore, the successful modelling of pyrolysis to predict the rate of volatile evolution is also of great importance. Pyrolysis experiments of waste spruce sawdust were carried out. During the experiment, gaseous products were analysed to determine a change in the gas composition with increasing temperature. Furthermore, the model of pyrolysis was created using Aspen Plus software. Aspects of pyrolysis are discussed with a description of how various temperatures affect the overall reaction rate and the yield of volatile components. The pyrolysis Aspen plus model was compared with the experimental data. It was discovered that the Aspen Plus model, being used by several authors, is not good enough for pyrolysis process description, but it can be used for gasification modelling

Novel application for exergy and thermoeconomic analysis of processes simulated with Aspen Plus

A visual basic application for Microsoft® Excel 2007 has been developed as a helpful tool to perform mass, energy, exergy and thermoeconomic (MHBT) calculations during the systematic analysis of energy processes simulated with Aspen Plus®. The application reads an Excel workbook containing three sheets with the matter, work and heat streams results of an Aspen Plus® simulation. The required information from the Aspen Plus® simulation and the algorithm/calculations of the application are described and applied to an Air Separation Unit (ASU). This application helps the designer when MHBT analyses are performed, as it increases the knowledge of the process simulated with Aspen Plus®. It’s a valuable tool not only because of the calculations performed, but also because it creates a new Excel workbook where the results and the formulae written on the cells are fully visible and editable. There is free access to the application and it has no protection allowing changes and improvements to be done

Steady state simulation and exergy analysis of supercritical coal-fired power plant with CO₂ capture

Integrating a power plant with CO₂ capture incurs serious efficiency and energy penalty due to use of energy for solvent regeneration in the capture process. Reducing the exergy destruction and losses associated with the power plant systems can improve the rational efficiency of the system and thereby reducing energy penalties. This paper presents steady state simulation and exergy analysis of supercritical coal-fired power plant (SCPP) integrated with post-combustion CO₂ capture (PCC). The simulation was validated by comparing the results with a greenfield design case study based on a 550 MWe SCPP unit. The analyses show that the once-through boiler exhibits the highest exergy destruction but also has a limited influence on fuel-saving potentials of the system. The turbine subsystems show lower exergy destruction compared to the boiler subsystem but more significance in fuel-saving potentials of the system. Four cases of the integrated SCPP-CO2 capture configuration was considered for reducing thermodynamic irreversibilities in the system by reducing the driving forces responsible for the CO₂ capture process: conventional process, absorber intercooling (AIC), split-flow (SF), and a combination of absorber intercooling and split-flow (AIC + SF). The AIC + SF configuration shows the most significant reduction in exergy destruction when compared to the SCPP system with conventional CO₂ capture. This study shows that improvement in turbine performance design and the driving forces responsible for CO₂ capture (without compromising cost) can help improve the rational efficiency of the integrated system

Stepwise Analysis Of Gasification Reactions With Aspen Plus And CPFD

The energy from biomass can be utilized through the thermochemical conversion processes of pyrolysis and gasification. Biomass such as wood chips is heated in a gasification reactor to produce a synthesis gas containing CO, H2 and CH4. The gas can be further processed to bioproducts or fuels. The thermochemical process involves devolatilization of wood followed by steam gasification, CO2 gasification, methanation, water gas shift reactions and methane reforming. To optimize the performance of the reactor, it is important to study each of the reactions separately. The reactions are simulated individually using the chemical process optimization software Aspen Plus. The results are compared with simulations performed with the Computational Particle Fluid Dynamic (CPFD) software Barracuda VR 15. The CPFD methodology solves the fluid and particle equations in three dimensions with the transient flow and is time-consuming. Aspen Plus is one dimensional and solves the included reactions fast. The results of the Aspen Plus and CPFD simulations, given as product gas compositions (CO, CO2, CH4 and H2), show that each reaction contributes to the product gas composition differently. Comparison between Aspen Plus and CPFD simulations of individual gasification reactions show good agreement. However, when all reactions are included in the simulations, there is a deviation in the volume fraction of product gas composition

INTEGRATING BIOMASS TO PRODUCE HEAT AND POWER AT ETHANOL PLANTS

Published in: Applied Engineering in Agriculture, Vol. 25(2): 227‐244Biomass, Renewable, Sustainable, Model, Gasification, Combustion, Emissions, Ethanol production, Combined heat and power, Resource /Energy Economics and Policy,

Hit and Miss: Leverage, Sacrifice, and Refusal to Deal in the Supreme Court Decision in Trinko

Under the rules of the Telecommunications Act of 1996, incumbent local exchange carriers, including Verizon, were obligated to lease parts of their local telecommunications network to any firm at “cost plus a reasonable profit” prices which could combine them at will, add retailing services and sell local telecommunication service as a rival to the incumbent. AT&T, an entrant in local telecommunications, leased parts of Verizon’s network. Trinko, a local telecommunications services customer of AT&T, sued Verizon alleging various anti-competitive actions of Verizon against AT&T, including that Verizon raised the costs of AT&T, its downstream retail rival. The Supreme Court held that Trinko’s complaint failed to state a claim under § 2 of the Sherman Act, and dismissed the complaint. I argue that Verizon had two monopolies in local telecommunications: a monopoly of the local telecommunications network, as well as a monopoly in retail local telecommunications services. The 1996 Act allowed for competition in retail services and also imposed cost-based pricing on leases of Verizon’s network. Verizon, unable to increase the lease price on its network, reverted to raising-rivals-costs strategies against its retail competitors. Thus, Verizon used its monopoly of the network infrastructure to disadvantage entrants in retail. In doing so, Verizon lost short term profits that it would have earned from leasing its network to entrants, since the 1996 Act had set the lease price at cost plus “reasonable profit.” Thus, Verizon is liable if the “sacrifice principle” is applied. According to the sacrifice principle, a defendant is liable if its conduct “involves a sacrifice of short-term profits or goodwill that makes sense only insofar as it helps the defendant maintain or obtain monopoly power.”Vertical Leverage, Refusal to Deal, Monopoly, Sacrifice Principle, Trinko

Confronto di tecnologie di gassificazione di rifiuti industriali

Lavoro atto ad acquisire dati su tecnologie di gassificazione a bassa e alta temperatura e gassificazione mediante torcia al plasma al fine di effettuare un confronto tramite sviluppo di modelli di processo su Aspen Plus

The Distribution of Saperda Inornata and Oberea Schaumii (Coleoptera: Cerambycidae) within the Crowns of Large Trembling Aspens, Populus Tremuloides

The larvae of Saperda inornata Say and Oberea schaumii LeConte inhabit the stems of trembling aspen (Populus tremuloides Michaux) root suckers and the twigs of larger trees. Nord et al. (1972a, 1972b) reported the biologies of these species in Upper Michigan and northern Wisconsin. S. inornata has a one or two year life cycle, probably depending on how early the egg is laid. Most (77.5%) 0. schaumii develop in three years while 5.0% require only two years and 17.5% require four years to develop. Knight (1963) described the distribution of galleries made by S. inornata and 0. schaumii in the crowns of large trembling aspen, P. tremuloides, in Upper Michigan. Similar distribution data were gathered from 180 large trembling aspen felled in a survey designed to determine the relative abundance of S. inornata and 0. schaumii in stands of different site quality (Nord and Knight 1972b). The analysis of that distribution data and comparisons with that of Knight (1963) are presented here. Inter- and intra-specific competition in light of the results and other behavioral information are discussed

The Relationship of the Abundance of \u3ci\u3eSaperda Inornata\u3c/i\u3e and \u3ci\u3eOberea Schaumii\u3c/i\u3e (Coleoptera: Cerambycidae) in Large Trembling Aspen, \u3ci\u3ePopulus Tremuloides\u3c/i\u3e, to Site Quality

Saperda inornata Say and Oberea schaumii LeConte are cerambycids that inhabit the stems of trembling aspen, Populus tremuloides Michaux, root suckers and the twigs of larger trees. The biologies of those species in northern Wisconsin and Upper Michigan were reported by Nord et al. (1972a and 1972b). S. inornata oviposits on the cambium under horseshoe- or shield-shaped egg niches gnawed in the outer bark by the female. The term egg niche, connotes an oviposition place prepared by the female using the mandibles and ovipositor (Linsley 1959). There are usually 2 or 3 egg niches at one level on the stem or twig, and a globose gall consisting of callus tissue forms there. The larvae feed in the cambial and callus tissue around the gall and require 1 or 2 years to complete development. The 0. schaurnii female gnaws an elongate, rectangular egg niche in the outer bark and deposits an egg on the cambium beneath it. The larva bores downward from the egg niche in the wood. Most individuals require 3 years to complete the life cycle; but some take only 2 years, while others take 4 years. A survey designed to determine the importance of the egg niches and galleries of S. inornata and 0. schaumii as infection courts of Hypoxylon pruinatum (Klotzsche) Cke. in large trembling aspen was begun in 1962 in Iron and Ontonogan Counties, Michigan. The data from that survey indicated that abundance of borers might be correlated with the site quality of the stand. Therefore in 1963 the survey was redesigned to detect differences in abundance between stands of different site quality. Since the redesign concerned only the selection of stands, not the sampling procedures used within the stand, most of the trees sampled in 1962 were incorporated into the redesigned survey. The data collected in conjuction with the survey also make possible conclusions regarding the distribution of borer galleries within the crowns of large trees. Those results and a discussion of competition between S. inornata and 0. schaurnii are given in another paper (Nord and Knight, 1972a). The incidence of H. pruinatum in the galleries was reported by Nord and Knight (1972b)

Simulation of DMC Transesterification Reaction using ASPEN PLUS

Computer simulation has been widely used in chemical engineering processes and its implementation in biodiesel industry is very useful. In this study, a pilot plant scale of DMC transesterification reaction is simulated and validated using ASPEN PLUS software