A rural agricultural-sustainable energy community model and its application to Felton Valley, Australia

Energy and food security require a delicate balance which should not threaten or undermine community prosperity. Where it is proposed to derive energy from conventional fossil fuel resources (such as coal, shale oil, natural gas, coal seam gas) located in established rural areas, and particularly where these areas are used for productive agricultural purposes, there are often both intense community concern as well as broader questions regarding the relative social, economic and environmental costs and benefits of different land uses and, increasingly, different energy sources. The advent of mainstream renewable energy technologies means that alternative energy options may provide a viable alternative, allowing energy demand to be met without compromising existing land uses. We demonstrate how such a Sustainable Energy Rural Model can be designed to achieve a balance between the competing social goals of energy supply, agricultural production, environmental integrity and social well-being, and apply it to the Felton Valley, a highly productive and resilient farming community in eastern Australia. Research into available wind and solar resources found that Felton Valley has a number of attributes that indicate its suitability for the development of an integrated renewable energy precinct which would complement, rather than displace, existing agricultural enterprises. Modelling results suggest a potential combined annual renewable energy output from integrated wind and solar resources of 1,287 GWh/yr from peak installed capacity of 713 MW, sufficient to supply the electrical energy needs of about 160,000 homes, in combination with total biomass food production of 31,000 tonnes per annum or 146 GWh/yr of human food energy. The portfolio of renewable energy options will not only provide energy source diversity but also ensures long-term food security and regional stability. The Felton Valley model provides an example of community-led energy transformation and has potential as a pilot project for the development of smart distributed grids that would negate the need for further expansion of coal mining and coal fired power stations

Integrated Model-Centric Decision Support System for Process Industries

To bring the advances in modeling, simulation and optimization environments (MSOEs), open-software architectures, and information technology closer to process industries, novel mechanisms and advanced software tools must be devised to simplify the definition of complex model-based problems. Synergistic interactions between complementary model-based software tools must be refined to unlock the potential of model-centric technologies in industries. This dissertation presents the conceptual definition of a single and consistent framework for integrated process decision support (IMCPSS) to facilitate the realistic formulation of related model-based engineering problems. Through the integration of data management, simulation, parameter estimation, data reconciliation, and optimization methods, this framework seeks to extend the viability of model-centric technologies within the industrial workplace. The main contribution is the conceptual definition and implementation of mechanisms to ease the formulation of large-scale data-driven/model-based problems: data model definitions (DMDs), problem formulation objects (PFOs) and process data objects (PDOs). These mechanisms allow the definition of problems in terms of physical variables; to embed plant data seamlessly into model-based problems; and to permit data transfer, re-usability, and synergy among different activities. A second contribution is the design and implementation of the problem definition environment (PDE). The PDE is a robust object-oriented software component that coordinates the problem formulation and the interaction between activities by means of a user-friendly interface. The PDE administers information contained in DMD and coordinates the creation of PFOs and PIFs. Last, this dissertation contributes a systematic integration of data pre-processing and conditioning techniques and MSOEs. The proposed process data management system (pDMS) implements such methodologies. All required manipulations are supervised by the PDE, which represents an important advantage when dealing with high volumes of data. The IMCPSS responds to the need for software tools centered in process engineers for which the complexity of using current modeling environments is a barrier for broader application of model-based activities. Consequently, the IMCPSS represents a valuable tool for process industries, as the facilitation of problem formulation is translated into incorporation of plant data in less error-prone manner, maximization of time dedicated to the analysis of processes, and exploitation of synergy among activities based on process models

Production of TAME and n-Propyl propionate by reactive distillation

Tese de doutoramento. Engenharia Química. 2006. Faculdade de Engenharia. Universidade do Port

Life cycle assessment (LCA) applied to the process industry: a review

Purpose : Life cycle assessment (LCA) methodology is a well-established analytical method to quantify environmental impacts, which has been mainly applied to products. However, recent literature would suggest that it has also the potential as an analysis and design tool for processes, and stresses that one of the biggest challenges of this decade in the field of process systems engineering (PSE) is the development of tools for environmental considerations. Method : This article attempts to give an overview of the integration of LCA methodology in the context of industrial ecology, and focuses on the use of this methodology for environmental considerations concerning process design and optimization. Results : The review identifies that LCA is often used as a multi-objective optimization of processes: practitioners use LCA to obtain the inventory and inject the results into the optimization model. It also shows that most of the LCA studies undertaken on process analysis consider the unit processes as black boxes and build the inventory analysis on fixed operating conditions. Conclusions : The article highlights the interest to better assimilate PSE tools with LCA methodology, in order to produce a more detailed analysis. This will allow optimizing the influence of process operating conditions on environmental impacts and including detailed environmental results into process industry

An Assessment of United States Ethanol Policy

From 1978 on there have been a series of legislative acts that have placed substantial protectionist burdens on the American taxpayer to provide incentives, credits and mandates for the production and use of ethanol under the rationale of reducing U.S. dependence on foreign sources of oil while purporting to economically benefit the American economy and strengthening American security. While there has been much discussion about the economic benefits of ethanol policy, there is growing literature suggesting that in addition to being neither economically nor environmentally beneficial, ethanol policy may not be achieving its intended goals. Connection between political contributions, policy formation, and the actual outcomes of the enacted policies does not appear to have been addressed. Throughout the course of ethanol policy development the narrow interests of some stakeholders may have been met at the expense of others. Given the very large economic and social costs of ongoing ethanol subsidies and mandates an exploration of such a nexus would be illuminating and valuable. Hence the question of this research will be: Has the ethanol energy policy of the United States, as outlined in legislative actions, requiring subsidies and mandates from taxpayers, been reflective of a deliberative democratic process that after taking into account the input and influence of various competing viewpoints has resulted in a beneficial national policy? Consequently have the policy outcomes of the legislative stakeholders matched the stated intentions of those involved in the deliberative debate that enacted it or, where have those objectives not been met? Research that can increase understanding of how such an important policy may have failed can inform policy deliberation in such diverse areas as agriculture, national security and energy policy while illuminating how and why such public policy was made. Examination of a policy created and continuing which may have failed the most basic cost benefit analysis and does very little to enhance national energy security could demonstrate how a distortion of the legislative process resulted in outcomes that differ markedly from the stated intentions of those who enacted the policy

Using mathematical models to track phosphorus in a full-scale wastewater treatment plant

The challenges associated with pollution, declining nutrients and water shortage, resulted in the need for strategies towards cost effective recovery of nutrients from waste types fed to wastewater treatment systems, to forms that are usable and possibly marketable, while ensuring maintenance of good effluent quality from the plant. To address these challenges, the plant wide model (PWM_SA) of Ikumi et al. (2015) was utilized to evaluate and propose operational strategies for Zeekoegat WWTW of the City of Tshwane to help with future design or optimized operation of the system. This goal was achieved by (i) acquisition of all necessary data from Zekoegat WWTP, (ii) Reconciliation of measured data and subsequent characterization of the influent WW using widely documented protocol to run an excel steady state model which uses explicit mass balanced equations and (iii) setting up Zeekoegat WWTW virtually within the WEST® dynamic simulation environment and ensuring that confidence is achieved in virtual replication of the plant before testing operational scenarios. The two operational strategies were simulated and evaluated using performance indices (PI's: operational cost index (OCI) and effluent quality index (EQI)) derived from a previous investigation by the International Water Association (IWA) benchmark simulation modelling task group (Copp, 2002, Nopenset al., 2010). These PI's were modified by De Ketele et al. (2018) and later extended by Coothen (2021) and they proved to be a useful approach to evaluating the environmental (EQI) and economic (OCI) impact of a WWTP based on any operational strategy implemented i.e., optimizing water resource recovery (WRRFs) and troubleshooting problems to improve our wastewater treatment systems in South Africa

Sustainability of algae derived biodiesel: A mass balance approach

A rigorous chemical engineering mass balance/unit operations approach is applied here to bio-diesel from algae mass culture. An equivalent of 50,000,000 gallons per year (0.006002 m3/s) of petroleum-based Number 2 fuel oil (US, diesel for compression–ignition engines, about 0.1% of annual US consumption) from oleaginous algae is the target. Methyl algaeate and ethyl algaeate diesel can according to this analysis conceptually be produced largely in a technologically sustainable way albeit at a lower available diesel yield. About 11 square miles of algae ponds would be needed with optimistic assumptions of 50 g biomass yield per day and m2 pond area. CO2 to foster algae growth should be supplied from a sustainable source such as a biomass-based ethanol production. Reliance on fossil-based CO2 from power plants or fertilizer production renders algae diesel non-sustainable in the long term

The Optimal Implementation of On-Line Optimization for Chemical and Refinery Processes.

On-line optimization is an effective approach for process operation and economic improvement and source reduction in chemical and refinery processes. On-line optimization involves three steps of work as: data validation, parameter estimation, and economic optimization. This research evaluated statistical algorithms for gross error detection, data reconciliation, and parameter estimation, and developed an open-form steady state process model for the Monsanto designed sulfuric acid process of IMC Agrico Company. The plant model was used to demonstrate improved economics and reduced emissions from on-line optimization and to test the methodology of on-line optimization. Also, a modified compensation strategy was proposed to improve the misrectification of data reconciliation algorithms and it was compared with measurement test method. In addition, two ways to conduct on-line optimization were studied. One required two separated optimization problems to update parameters, and the other combined data validation and parameter estimation into one optimization problem. Two-step estimation demonstrated a better performance in estimation accuracy than one-step estimation for sulfuric acid process, while one-step estimation required less computation time. The measurement test method, Tjoa-Biegler\u27 contaminated Gaussian distribution method, and robust method were evaluated theoretically and numerically to compare the performance of these methods. Results from these evaluation were used to recommend the best way to conduct on-line optimization. The optimal procedure is to conduct combined gross error detection and data reconciliation to detect and rectify gross errors in plant data from DCS using Tjoa-Biegler\u27s method or robust method. This step generates a set of measurements containing only random errors which is used for simultaneous data reconciliation and parameter estimation using the least squares method (the normal distribution). Updated parameters are used in the plant model for economic optimization that generates optimal set points for DCS. Applying this procedure to the Monsanto sulfuric acid plant had an increased profit of 3% over current operating condition and an emission reduction of 10% which is consistent with other reported applications. Also, this optimal procedure to conduct on-line optimization has been incorporated into an interactive on-line optimization program which used a window interface developed with Visual Basic and GAMS to solve the nonlinear optimization problems. This program is to be available through the EPA Technology Tool Program