Simultaneous process and molecular design/selection through property integration

The overall purpose of this work is to develop systematic methodology for the simultaneous design and selection of processes and molecules (materials). A propertybased approach is used to develop an interface between process and molecular design/selection. In particular, we focus on the problem of designing/selecting materials that are used in the context of a recycle/reuse system of process streams and for energy applications. Fresh and recycled resources (e.g., process streams, biomass, solvents, etc.) are integrated with the process to satisfy property-based constraints for the process units and to optimize the usage of the resources and the design of the process. For molecular design, property operators for mixing streams and group contribution methods (GCM) are used to consistently represent process sources, sinks, and different functional groups on the same property-base. For material selection, property based criteria (e.g., heat rate, high heating value, etc.) are used to bridge the process with material. This consistent representation enables the definition of the optimization problem formulation for product design while taking into consideration the recycle/reuse of process streams. In particular, this dissertation addresses four integrated topics. First, a new graphical approach for material targeting and substitution is presented. This graphical approach offers initial solutions and valuable insights that can be effectively used for conceptual design and for initializing mathematical programming techniques. Second, a mathematical optimization approach is developed along with a decomposition-based global solution procedure for material targeting and substitution using property integration. Third, an implementation approach is developed to synthesize the details of a recycle/reuse process network design based on the targets identified through the graphical and/or the mathematical approaches. Finally, property integration techniques are extended to a broader scope which deals with the lifecycle analysis of biomass utilization for energy generation. A generic model is developed to optimize the types and quantities of the feedstocks used to optimize power generation with biomass-fossil fuel co-fed system. Important issues of biomass growth, harvesting, transportation, processing, and disposal are included. Property-based tracking and constraints are included in the analysis. Also, the issues associated with greenhouse gas (GHG) emissions are incorporated in the analysis. Case studies are solved throughout the dissertation to demonstrate the applicability of the developed procedures

Innovative, effective and sustainable technology and logistics for forest residual biomass

Luken kirjat, raportit, oppaat ja esitteet. Summary of the INFRES project results201

Social, environmental and economic impacts of alternative energy and fuel supply chains

Energy supply nowadays, being a vital element of a country’s development, has to independently meet diverse, sustainability criteria, be it economic, environmental and social. The main goal of the present research work is to present a methodological framework for the evaluation of alternative energy and fuel Supply Chains (SCs), consisting of a broad topology (representation) suggested, encompassing all the well-known energy and fuel SCs, under a unified scheme, a set of performance measures and indices as well as mathematical model development, formulated as Multi-objective Linear Programming with the extension of incorporating binary decisions as well (Multi-objective Mixed Integer-Linear programming). Basic characteristics of the current modelling approach include the adaptability of the model to be applied at different levels of energy SCs decisions, under different time frames and for multiple stakeholders. Model evaluation is carried for a set of Greek islands, located in the Aegean Archipelagos, examining both the existing energy supply options as well future, more sustainable Energy Supply Chains (ESCs) configurations. Results of the specific research work reveal the social and environmental costs which are underestimated under the traditional energy supply options' evaluation, as well as the benefits that may be produced from renewable energy based applications in terms of social security and employment

Techno-economic feasibility of electrifying food markets in Nigeria with biogas hybrid mini-grids

This thesis explored the feasibility of electrifying a food market in an urban city in Nigeria with a hybrid biogas-powered mini-grid. Under the Energizing Economies Initiative of the Rural Electrification Agency of Nigeria, nine markets in the country currently receive constant access to electricity via hybrid mini-grid systems. As a majority of these systems are diesel-solar-battery systems, this thesis explored the use of biogas generators as a substitute for diesel generators in hybrid mini-grids for food markets. A fruit and vegetable market in Ketu, Lagos was used as a case study for the research. The research for this thesis was carried out using various research methods which include literature reviews, phone-call interviews, and quantitative modeling analysis using HOMER Pro and Microsoft Excel software. The analysis focused on two load types determined by two energy solutions, cooling as a service (CaaS) and power as a service (PaaS), proposed for the market. The simulated load in the CaaS case was 277 kWh/day, while that in the PaaS case was 581 kWh/day. The results obtained indicate the technical feasibility, economic viability, and environmental benefit of generating electricity using a hybrid biogas mini-grid. The optimal system design for achieving this was a Biogas-Solar-Battery system. The cost of energy for this system was found to be $0.242/kWh and$0.169/kWh for the CaaS and PaaS solutions, respectively. The use of biogas fuel for electricity generation in this system diverted 185 kg and 107 kg of biomass from the landfill in the CaaS and PaaS solution respectively. This reduction in biomass waste at the landfill reduces methane emissions. For a diesel-solar-battery system, fuel costs, which accounted for 79% of the annual O&M cost of the system, resulted in a high COE of $0.270/kWh for the PaaS solution. Hence, biogas was found to be a cheaper substitute for diesel fuel. Lastly, the cost of energy of a biogas-only system for the PaaS solution was$0.169/kWh. Although a biogas only system has a greater greenhouse gas reduction potential compared to a hybrid biogas solution, the reliability of such a system is not guaranteed as it is dependent on one energy source

Analysis of operational issues in hydrothermal liquefaction and supercritical water gasification processes: a review

Biomass is often referred to as a carbon–neutral energy source, and it has a role in reducing fossil fuel depletion. In addition, biomass can be converted efficiently into various forms of biofuels. The biomass conversion processes involve several thermochemical, biochemical, and hydrothermal methods for biomass treatment integration. The most common conversion routes to produce biofuels include pyrolysis and gasification processes. On the other hand, supercritical water gasification (SCWG) and hydrothermal liquefaction (HTL) are best suitable for converting biomass and waste with high moisture content. Despite promising efficiencies, SCWG and HTL processes introduce operational issues as obstacles to the industrialization of these technologies. The issues include process safety aspects due to operation conditions, plugging due to solid deposition, corrosion, pumpability of feedstock, catalyst sintering and deactivation, and high production costs. The methods to address these issues include various reactor configurations to avoid plugging and optimizing process conditions to minimize other issues. However, there are only a few studies investigating the operational issues as the main scope, and reviews are seldomly available in this regard. Therefore, further research is required to address operational problems. This study reviews the main operational problems in SCWG and HTL. The objective of this study is to enhance the industrialization of these processes by investigating the operational issues and the potential solutions, i.e., contributing to the elimination of the obstacles. A comprehensive study on the operational issues provides a holistic overview of the biomass conversion technologies and biorefinery concepts to promote the industrialization of SCWG and HTL.Fil: Ghavami, Niloufar. Abo Akademi; FinlandiaFil: Özdenkçi, Karhan. Abo Akademi; FinlandiaFil: Salierno, Gabriel Leonardo. Abo Akademi; Finlandia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Björklund Sänkiaho, Margareta. Abo Akademi; FinlandiaFil: De Blasio, Cataldo. Abo Akademi; Finlandi

An integrated approach for techno-economic and environmental analysis of energy from biomass and fossil fuels

Biomass conversion into forms of energy is receiving current attention because of environmental, energy and agricultural concerns. The purpose of this thesis is to analyze the environmental, energy, economic, and technological aspects of using a form of biomass, switchgrass (panicum virgatum), as a partial or complete replacement for coal in power generation and cogeneration systems. To examine the effects of such a substitution, an environmental biocomplexity approach is used, wherein the agricultural, technological, economic, and environmental factors are addressed. In particular, lifecycle analysis (LCA) and a three-dimensional integrated economic, energy and environmental analysis is employed. The effectiveness of alternate technologies for switchgrass preparation, harvest and use in terms of greenhouse gas impact, cost and environmental implications is examined. Also, different scenarios of cofiring and biomass preparation pathways are investigated. Optimization of the total biomass power generation cost with minimum greenhouse gas effect is undertaken using mathematical programming for various alternate competitive biomass processing pathways. As a byproduct of this work a generic tool to optimize the cost and greenhouse gas emissions for allocation of fuel sources to the power generating sinks is developed. Further, this work discusses the sensitivity of the findings to varied cofiring ratios, coal prices, hauling distances, per acre yields, etc. Besides electricity generation in power plants, another viable alternative for reducing greenhouse gases (GHGs) is the utilization of biomass in conjunction with combined heat and power (CHP) in the process industries. This work addresses the utilization of biowaste or biomass source in a processing facility for CHP. A systematic algebraic procedure for targeting cogeneration potential ahead of detailed power generation network design is presented. The approach presented here effectively utilizes the biomass and biowaste sources as external fuel, and matches it with the use and dispatch of fuel sources within the process, heating and non-heating steam demands, and power generation. The concept of extractable energy coupled with flow balance via cascade diagram has been used as a basis to construct this approach. The work also discusses important economic factors and environmental policies required for the cost-effective utilization of biomass for electricity generation and CHP

Renewable Energy

This book discusses renewable energy resources and systems as well as energy efficiency. It contains twenty-three chapters over six sections that address a multitude of renewable energy types, including solar and photovoltaic, biomass, hydroelectric, and geothermal. The information presented herein is a scientific contribution to energy and environmental regulations, quality and efficiency of energy services, energy supply security, energy market-based approaches, government interventions, and the spread of technological innovation

Local alternative sources for cogeneration combined heat and power system

Global demand for energy continues to grow while countries around the globe race to reduce their reliance on fossil fuels and greenhouse gas emissions by implementing policy measures and advancing technology. Sustainability has become an important issue in transportation and infrastructure development projects. While several agencies are trying to incorporate a range of sustainability measures in their goals and missions, only a few planning agencies have been able to implement these policies and they are far from perfect. The low rate of success in implementing sustainable policies is primarily due to incomplete understanding of the system and the interaction between various elements of the system. The conventional planning efforts focuses mainly on performance measures pertaining to the system and its impact on the environment but seldom on the social and economic impacts. The objective of this study is to use clean and alternative energy can be produced from many sources, and even use existing materials for energy generation. One such pathway is using wastewater, animal and organic waste, or landfills to create biogas for energy production. There are three tasks for this study. In topic one evaluated the energy saving that produced from combined hydrogen, heat, and power and mitigate greenhouse gas emissions by using local sustainable energy at the Missouri S&T campus to reduce energy consumption and fossil fuel usage. Second topic aimed to estimate energy recovery and power generation from alternative energy source by using Rankin steam cycle from municipal solid waste at Benghazi- Libya. And the last task is in progress. The results for topics one and two have been presented --Abstract, page iv

AN ASSESSMENT OF THE EFFICACY AND COST OF ALTERNATIVE CARBON MITIGATION POLICIES FOR THE STATE OF INDIANA

A nation-wide climate policy targeting the power sector might lead to dramatic changes to Indiana\u27s electricity generation system. This is because Indiana relies heavily on coal as its primary source for electricity generation and coal is much more carbon-intensive than other fossil fuels. In the possible event that Indiana will have to take action on carbon mitigation, for example because of a national climate policy in the future, it is important for state policymakers to understand the costs and efficacy of alternative strategies. In addition, assessing the impacts of the policy alternatives on Indiana serves as guidance for the national policy design process regarding the subnational impacts