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This study presents the mathematical formulation and implementation of a comprehensive optimization framework for the assessment of shale gas resources. The framework simultaneously integrates water management and the design and planning of the shale gas supply chain, from the shale formation to final product demand centers and from fresh water supply for hydraulic fracturing to water injection and/or disposal. The framework also addresses some issues regarding wastewater quality, i.e., total dissolved solids (TDS) concentration, as well as spatial and temporal variations in gas composition, features that typically arise in exploiting shale formations. In addition, the proposed framework also considers the integration of different modeling, simulation and optimization tools that are commonly used in the energy sector to evaluate the technical and economic viability of new energy sources. Finally, the capabilities of the proposed framework are illustrated through two case studies (A and B) involving 5 well-pads operating with constant and variable gas composition, respectively. The effects of the modeling of variable TDS concentration in the produced wastewater is also addressed in case study B.

Designing effective environmental policies for mitigating global warming is a very challenging task that requires detailed knowledge of the international channels through which goods are traded. This work presents a decision-support tool that minimizes the environmental impact at a global macroeconomic scale by performing changes in the economic sectors of an economy. Our tool combines multi-objective optimization, environmentally extended input–output tables and life cycle assessment within a unified framework. Our results on the U.S. economy to minimize CO2 emissions identify sectors that should be regulated first to reach a given environmental target while maximizing the demand satisfaction. The impact of shale gas on our results is also studied. Our findings show that the application of process systems engineering tools at a macroeconomic level can provide valuable insight for public policy makers into problems of general interest. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3639–3656, 2016

Shale gas production has been the focus of intense debate in recent years. Shale gas supporters claim that it could be the way to transition between fossil fuels and renewable energy sources. For instance, in the United States, power generation from coal is being replaced by power generation from natural gas, which is a cleaner fuel when compared to coal. However, shale gas critics claim that the environmental cost associated with shale gas production is high enough to negate the benefits to society. For example, high water usage as well as the potential for contamination of underground and surface water sources constitute important environmental challenges for the development of shale gas resources. This study presents a methodology for the preliminary assessment of the development of shale gas resources taking into account well-pad design as one of the most important decision variables. To perform the assessment, different performance metrics are proposed to evaluate not only the economics of developing...

Economic, energy, and sustainability metrics are key performance indicators for process operations. The relative importance of these metrics varies from plant to plant, and often some metrics are in conflict with each other (sustainability vs. profitability). In this paper we discuss the current plant environment and how various metrics can be aligned by focusing on energy efficiency. Power-steam systems are the major energy drivers for most plants, and we discuss possible operational changes that might improve energy efficiency, as well as the role of process control. Managing the interplay of real-time optimization and regulatory control is a challenge for the future, as well as interfacing with the implementation of smart power grids by the utility industry. Combined heat and power along with energy storage presents interesting control and optimization opportunities to maximize energy efficiency.

The recent shale gas boom has transformed the energy landscape of the United States. Compared to natural gas, shale resources contain a substantial amount of condensate and natural gas liquids (NGLs). Many shale basin regions located in remote areas are lacking the infrastructure to distribute the extracted NGLs to other regions&mdash, particularly the Gulf Coast, a major gas processing region. Here we present a shale gas transformation process that converts NGLs in shale resources into liquid hydrocarbons, which are easier to transport from these remote basins than NGL or its constituents. This process involves catalytic dehydrogenation followed by catalytic oligomerization. Thermodynamic process analysis shows that this process has the potential to be more energy efficient than existing NGL-to-liquid fuel (NTL) technologies. In addition, our estimated payback period for this process is within the average lifetime of shale gas wells. The proposed process holds the promise to be an energy efficient and economically attractive step to valorize condensate in remote shale basins.

Catalysis is the essential technology for chemical transformation, including production of fuels from the fossil resources petroleum, natural gas, and coal. Typical catalysts for these conversions are robust porous solids incorporating metals, metal oxides, and/or metal sulfides. As efforts are stepping up to replace fossil fuels with biomass, new catalysts for the conversion of the components of biomass will be needed. Although the catalysts for biomass conversion might be substantially different from those used in the conversion of fossil feedstocks, the latter catalysts are a starting point in today's research. Major challenges lie ahead in the discovery of efficient biomass conversion catalysts, as well as in the discovery of catalysts for conversion of CO2 and possibly water into liquid fuels.

In this work, an optimization framework to support the planning of the development of shale gas resources is proposed. Financial aspects are taken into account through the integration of financing options, such as own capital, and external sources, short and long term bank credit lines. The model also includes the design of well-pads in terms of total number of wells, and length and number of hydraulic fractures completed at each well. In addition, different capacities and locations are considered for compressor stations, gas separation plants, and water treatment plants. A case study involving two alternative financing strategies was conducted to demonstrate the capabilities of the model. It is found that external financing can play an important role in the development of a shale gas field, achieving an increase in net profit of almost 65 % when compared to a scenario where only own capital is considered.

Means-Ends Analysis is an operator-based state transformation paradigm often used in automated goal-oriented problem solving. The method is most frequently applied in a forward-chaining or opportunistic manner from well defined states. Systematic generation approaches to chemical process synthesis, however, are decidedly hierarchical in focus, in procedure, and in property differences to resolve and design difficulties to overcome. To accommodate this hierarchical environment, the means-ends paradigm has been modified to include the idea of strategic operations in addition to opportunistic operations. The input state for strategic operations may not completely instantiated at the time they are applied. Such transformations may be considered as “islands” until they become linked with defined states. The strategic approach is illustrated in the context of overall flowsheet synthesis and also as an essential aspect of a new algorithm for separations synthesis for nonideal mixtures.

There is much interest in concepts of sustainability within the chemical industry, especially related to health, safety, and environmental performance, product stewardship, value chain management, efficient use of resources, and mitigation of potential climate change. However, perhaps the greatest sustainability challenges are those associated with energy production and consumption. Energy consumption directly contributes to the majority of carbon dioxide emissions, and recent estimates of future economic growth imply that global energy consumption may more than triple over the coming decades. Since at present carbon capture and sequestration technologies are very expensive, in difficult economic times emphasis will be given first to energy conservation and fuel switching as primary carbon management approaches. A number of current issues will be discussed including economic limitations to implementing energy conservation in retrofit situations, new approaches to the optimal control of energy during process operations, techniques to hasten the utilization of biomass energy sources, and the impacts of shale gas development.

Separations process synthesis is the invention of conceptual flow sheets for the separation of multicomponent mixtures. Systematic methods are available to aid in the generation of separations schemes for analysis and evaluation. For fluid systems, distillation remains the separation method of choice. This article describes heuristic methods for generating alternative distillation schemes for nonazeotropic mixtures as well as a more general method for generating separation schemes for nonideal liquid mixtures including systems involving azeotropes. This latter method makes use of the residue curve map representation for vapor–liquid equilibria and introduces the concepts of strategic and opportunistic operations to systematically overcome difficulties introduced by azeotropes and other nonidealities. Mention is also given to separation synthesis methods for gas or vapor mixtures and for systems which involve dissolved solids. Keywords: Heuristic distillation; Nonazeotropic mixtures; Separation synthesis; Nonideal liquid mixtures; Selection issues; Gas-vapor mixtures; Dissolved solids; Flow sheet generation; Separation synthesis algorithms

Publisher Summary This chapter gives an overview or summary of PSE2003 and the impact of business decision making on the future of PSE.

Systematic approaches for the invention of conceptual chemical process designs have been proposed and discussed for more than twenty-five years. During that same time, the importance of front-end engineering, especially conceptual design, to product quality, health and safety, environmental impact, energy consumption, operability, capital and operating costs, and overall competitiveness has become ever more apparent. A number of process synthesis frameworks, approaches, methods, and tools have now been developed to the point of industrial application. This chapter describes a framework for the industrial chemical plant innovation process, showing how process synthesis fits into that structure and how that framework has in turn influenced the development of systematic process synthesis methods. It also describes a number of industrial case studies in which process synthesis techniques have been successfully applied to the conceptual design of total process flowsheets, as well as to specific design subproblems including heat-integrated distillation trains, multiple-effect distillation, and the separation of azeotropic systems. Typical energy savings of 50% and net present cost reductions of 35% have been achieved in industrial practice using systematic process synthesis methodologies. Even greater benefits are expected to be realized as the next generation of approaches currently being developed is transferred to industry.