Record Types
Records with Type: Conference Presentation
High Order Modeling of Overdamped Continuous Processes
Francisco Sanchez Careaga, Carlos Narvaez
November 2, 2018 (v1)
Keywords: Dynamic System Analysis, Process Control, Process Identification, Process Modeling
The dynamic response of continuous processes is a key issue for their control. To represent this
response, first order models are used, mainly because of their simplicity and the lack of simple methods for parameter estimation of higher order models. Although first order models may be sufficient in many cases, there are times when a higher order model needs to be used to achieve good control. This paper presents a simple graphical procedure for the estimation of the two time constants, the gain, and the dead time of a second order linear model. The procedure uses only four readings from the step response curve of the processes, and very simple formulas to determine parameter values.
Measurement of penetration and cycle time of jets from an industrial fluid coking spray nozzle
Francisco Sanchez Careaga, Cedric Briens, Franco Berruti
October 30, 2018 (v1)
Keywords: Fluidization, Liquid Injection in Fluidized Beds
Fluid CokingTM is a process to upgrade heavy oils through thermal cracking. Oil is injected in a downward-flowing bed of hot coke particles, where it heats up and cracks into smaller vapour molecules. The down-flowing coke particles are sent to a burner where they are reheated and send back to the reactor to provide heat for cracking reactions. Liquid sprayed with atomization gas into a fluidized bed forms a jet cavity that absorbs bubbles from the bubbling bed and periodically releases a large bubble from its tip. The jet penetration length, thus, cycles. With a faster jet cycle, the liquid is distributed more uniformly inside the bed, which is highly desirable. Poor liquid distribution increases the formation of wet agglomerates that slow down the coking reactions and lead to operating problems in commercial Fluid CokersTM. A novel method is proposed to measure the jet penetration and cycle time in large, room-temperature fluidized beds. It is applied to the study of jet cavities fro... [more]
A novel sustainable design for production of liquid fuels
Leila Hoseinzade, Thomas A Adams II
October 30, 2018 (v1)
In this study, a novel biomass-gas-and-nuclear-to-liquids (BGNTL) process is proposed. In this process, nuclear heat is used as the heat source of a steam methane reforming (SMR) process. In a prior work, a rigorous model was developed for the integrated nuclear heat and steam methane reforming process in the gPROMS software package. This model was applied to simulate the integrated nuclear heat and SMR section of BGNTL in Aspen Plus within the other process sections. The BGNTL process was considered for producing different fuels including gasoline & diesel or dimethyl ether (DME). Carbon capture and sequestration (CCS) is considered as an optional section. The performance of the BGNTL process was compared against a non-nuclear process called biomass-and-gas-to-liquids (BGTL). The efficiency, economics, and environmental impact analyses show that the BGNTL process to produce DME is the most efficient, economic and environmentally friendly process among the considered designs. As a resu... [more]
Techno-Economic Analysis of Combining Petroleum Coke and Natural Gas for Efficient Liquid Fuels Production
Ikenna Joseph Okeke, Thomas A Adams II
October 30, 2018 (v1)
Subject: Uncategorized
Waste petcoke can be converted to liquid fuels instead of stockpiling which reduces the net CO2 emission by displacing additional petroleum usage. In this study, three petcoke to liquid fuels designs were compared based on the following performance criteria: conversion efficiency, economics, and environmental impacts. The designs considered were petcoke gasification only, a combination of natural gas reforming and petcoke gasification, and natural gas reforming integrated in the petcoke gasification step. The processes were modeled and simulated using a combination of Aspen Plus v10, ProMax, and gProms software. Each of the configurations were designed to operate with and without carbon capture and sequestration (CCS) technology along with a corresponding carbon emission penalty. Performance metrics analyzed were the net present value, minimum diesel selling price, cost of CO2 avoided, and cradle to plant exit gate life cycle greenhouse gas emissions. From the analysis, the integration... [more]
Techno-economic System Analysis for SOFC/GT Hybrid System Accounting for Degradation Effects
Haoxiang Lai, Thomas Adams II
October 30, 2018 (v1)
Keywords: Modeling and simulation, Process design, SOFC/GT Hybrid, Technoeconomic Analysis
Solid oxide fuel cells (SOFCs) produce power with higher efficiency and lower greenhouse gas emission than conventional power production systems such as coal/natural gas power plants. However, a major challenge with SOFCs is that they degrade over time, leading to a short lifetime and limiting their commercialization. When operated in constant power mode—the most common way of baseload power production—the lifetime of an SOFC is as short as around 1.5 years. As an SOFC starts to degrade, the fuel rate and current density must increase in order to compensate and keep power production at a constant level. This compounds the problem by actually increasing the rate of degradation further, resulting in an exponentially increasing degradation rate and therefore a short lifetime.
It has recently been found that by operating the SOFC differently with constant voltage instead of power, the degradation rate can be slowed such that the cell lifetime can be increased to around 13-14 years. In th... [more]
Rolling Horizon Model for Gasoline Blend Planning under Uncertainty in Demands
mahir jalanko, Vladimir Mahalec
October 30, 2018 (v1)
Keywords: production planning under uncertainty, supply-demand pinch
Use rolling horizon model to solve the gasoline blend planning under uncertainty in products demands. We show that an aggregated model based on supply-demand pinch points can improve executions times greatly
Meta-study of carbon dioxide capture technologies: Finding the signal in the noise.
Thomas Alan Adams II, Leila Hoseinzade, Pranav Bhaswanth Madabhushi, Ikenna J. Okeke
October 31, 2018 (v2)
Keywords: Carbon Capture, Carbon Dioxide Sequestration, Chemical Looping Combustion, CO2 membrane, IGCC, Oxyfuels, Post-combustion capture, Pre-combustion capture, Solid Oxide Fuel Cells
We conducted a meta-study of CO2 capture processes, examining nearly 100 techno-economic analyses published in the recent open literature. Normally, it is difficult to compare one study to another because each study uses its own set of assumptions, such as plant scale, geography, market parameters, and inconsistent definitions of key metrics such as the cost of CO2 avoided (CCA). In this work, we present normalized versions of these studies using a consistent basis of comparison, such as net power delivered, base year of operation, pipeline CO2 pressure, currency, country of construction, and so on. In so doing, we are able to draw meaningful conclusions and direct comparisons between different classes of CO2 capture technology. The technologies considered include coal and gas-based processes using capture strategies including solvent-based post-combustion carbon capture, gasification-based strategies, membrane-based approaches, oxyfuel combustion, chemical looping combustion, calcium... [more]
Dynamic modeling of the integrated methane reforming and nuclear heat systems
Leila Hoseinzade, Thomas A Adams II
August 15, 2018 (v1)
Keywords: Carbonless Heat, Dynamic Modelling, Methane Reforming, Process integration
In this study, a dynamic and two-dimensional model for a steam methane reforming process integrated with nuclear heat production was developed. The model is based on first principals and considers the conservation of mass, momentum and energy within the system. Very few model parameter needed to be fit based on the experimental data reported in the literature. Using the fitted model and existing data, an industrial scale design for the integrated steam reforming and nuclear heat process is proposed. The system performance was analyzed by studying the dynamic behaviour of the key variables of the system. It has been shown that the methane conversion in the SMR tubes are generally lower than conventional reforming processes due to the low temperature of the gas flows in the shell side. Several options were investigated to increase the conversion of the methane in the SMR tubes, we found that combining steam reforming with dry reforming processes together can provide significant improveme... [more]
Combining Biomass, Natural Gas, Carbonless Heat to produce liquid fuels
Leila Hoseinzade, Thomas A Adams II
August 15, 2018 (v1)
Keywords: Biomass, Carbonless Heat, Natural Gas, Polygeneration
In this study, a new Biomass-Gas-Nuclear heat-To-Liquid fuel (BGNTL) process is presented which uses high-temperature nuclear heat as the heat source for steam methane reforming (SMR). This process co-produces liquid fuels (Fischer-Tropsch liquids, methanol and DME) and power. The BGNTL process was simulated using a combination of different software packages including gPROMS, MATLAB, ProMax, and Aspen Plus. This included the use of a rigorous multi-scale model for the nuclear-heat-powered SMR reactor which was developed in a prior work in gPROMS. Energy efficiency and cradle-to-grave life cycle inventory and life-cycle impact analyses of greenhouse gas (GHG) emissions were accomplished to analyze the environmental impacts of the BGNTL system. Plant performance was compared with a base case Biomass-Gas-To-Liquid (BGTL) process at the same size. In both processes, a carbon capture and storage (CCS) option is considered. It has been found that both processes result in negative total life... [more]
Integrated Process Design and Control of Cyclic Distillation Columns
Seyed Soheil Mansouri
July 30, 2018 (v1)
Keywords: Cyclic Distillation, Driving Froce, Process Control, Process Design, Process Intensification
Integrated process and control design approach for cyclic distillation columns is proposed. The design methodology is based on application of simple graphical design approaches, known from simpler conventional distillation columns. Here, a driving force approach and McCabe-Thiele type analysis is combined. It is demonstrated, through closed-loop and open-loop analysis, that operating the column at the largest available driving force results in an optimal design in terms of controllability and operability. The performance of a cyclic distillation column designed to operate at the maximum driving force is compared to alternative sub-optimal designs. The results suggest that operation at the largest driving force is less sensitive to disturbances in the feed and inherently has the ability to efficiently reject disturbances.
Transforming Instruction to Chemical Product Design
Ka M Ng, Warren D Seider
July 11, 2018 (v1)
Subject: Education
Keywords: Innovation, Product Design, Teaching Assessment, Technology Platforms
This paper describes the progress of our efforts to lead the CACHE (Computer Aids for Chemical Engineering Education) Task Force in transforming from chemical process design toward chemical product design. Through CACHE, we are coordinating the development of a library of product-design case studies. Beginning with preliminary product designs created previously over several semesters, we are arranging for faculty experts, knowledgeable in the underlying technology platforms, to work with student groups to enrich the product designs. Over a 3-year period, a collection of approximately 25 case studies is being prepared. This article describes the research envisioned as innovative product designs are created, both egarding applications of new technologies, and product design evolution/evaluation; and in advancing strategies for teaching product design. The anticipated use of these case studies in departments worldwide for design courses taught by similar technology experts, just a few in... [more]
Future directions in process and product synthesis and design
Mariano Martín, Thomas A. Adams II
June 25, 2018 (v1)
Keywords: Future Directions, LAPSE, Process Design, Product Design, PSE Technology Tree
We present an overview of the current state-of-the-art of the field of chemical process and product synthesis and design. In this talk, we outline some of the most interesting new challenges and directions for the field, including: new pushes for including renewable energy into chemical systems, related issues with energy storage, the move toward flexible and unsteady-state chemical processes, the considerations of uncertainty into the design process, new advances in specialty processes, process intensification, modularization, and more. Also, we announce and present the PSE Technology Tree Wiki, a community-based encyclopedia for the PSE community that organizes concepts into a technology tree. We also announce and present LAPSE: the Living Archive for Process Systems Engineering, a new open-data / open-access repository for the PSE community, which contains unique and innovative features designed to foster better dissemination of research, easy access to open models and simulations,... [more]
[Show List of Record Types]