Separation and Recovery of Intracellular Beta-Carotene Using a Process Synthesis Framework with Targeted Experiments

Systematic process synthesis approaches are widely applied to traditional chemical process industries, but have seen limited use in the bioprocessing industry due to the limited or non-existent availability of thermodynamic or kinetic data. In this work, the process synthesis problem for the bio-manufacturing of high-value intracellular compounds is addressed using a systematic framework that allows for the user to input key process parameters from literature or experiments. The framework is based on a superstructure optimization approach and integrates various methods and tools, including a generic model and a database for data management. We propose the following five steps: (1) problem formulation, (2) data collection and superstructure generation, (3) solution of the optimization problem, and (4) process parameter analysis and (5) experimentation with informed design and then determination of the optimal process design. The framework is implemented in Super-O, software which guides the user through the formulation and solution of synthesis problems. This thesis demonstrates the proposed framework though an illustrative case study on the production of beta-carotene from recombinant Saccharomyces cerevisiae (SM14) via continuous cultivation using experimental, simulation and literature values

Systematic sustainable process design and analysis of biodiesel processes

Biodiesel is a promising fuel alternative compared to traditional diesel obtained from conventional sources such as fossil fuel. Many flowsheet alternatives exist for the production of biodiesel and therefore it is necessary to evaluate these alternatives using defined criteria and also from process intensification opportunities. This work focuses on three main aspects that have been incorporated into a systematic computer-aided framework for sustainable process design. First, the creation of a generic superstructure, which consists of all possible process alternatives based on available technology. Second, the evaluation of this superstructure for systematic screening to obtain an appropriate base case design. This is done by first reducing the search space using a sustainability analysis, which provides key indicators for process bottlenecks of different flowsheet configurations and then by further reducing the search space by using economic evaluation and life cycle assessment. Third, the determination of sustainable design with/without process intensification using a phenomena-based synthesis/design method. A detailed step by step application of the framework is highlighted through a biodiesel production case study

From conceptual design to process design optimization: a review on flowsheet synthesis

International audienceThis paper presents the authors’ perspectives on some of the open questions and opportunities in Process Systems Engineering (PSE) focusing on process synthesis. A general overview of process synthesis is given, and the difference between Conceptual Design (CD) and Process Design (PD) is presented using an original ternary diagram. Then, a bibliometric analysis is performed to place major research team activities in the latter. An analysis of ongoing work is conducted and some perspectives are provided based on the analysis. This analysis includes symbolic knowledge representation concepts and inference techniques, i.e., ontology, that is believed to become useful in the future. Future research challenges that process synthesis will have to face, such as biomass transformation, shale production, response to spaceflight demand, modular plant design, and intermittent production of energy, are also discussed

Superstructure Optimization of Naphtha Processing System with Environmental Considerations

The objective of this research project is to develop an optimization-based mathematical model in the form of a mixed-integer linear program (MILP) for determining the optimal configuration of a petroleum refmery. The scope for this project is to formulate the superstructure representation model for a refinery focusing on the subsystem of naphtha hydroprocessing in order to select the most economical and cost efficient process route. The alternatives for all streams are evaluated and the optimal configuration is proposed based on market demand by incorporating logical constraints and mass balance using the GAMS modeling language platform. Based on the information and knowledge about the physics of the problem of naphtha processing unit, we represent all these possible processing alternatives on a superstructure. Carbon dioxide emission factors bave also been considered in which relevant data is obtained using the carbon weighting tonne (CWT) method. Computational studies are conducted on a representative numerical example to illustrate the proposed modeling approach

Risk-conscious optimization model to support bioenergy investment in the Brazilian sugarcane industry

The past decades have seen a diversification of the sugarcane industry with the emergence of new technology to produce bioenergy from by-product and waste process streams. Given Brazil’s ambitious goal of reducing green-house gas emissions by over 40% below 2005 levels by 2030, it is of paramount importance to develop reliable decision-making systems in order to stimulate investment in these low-carbon technologies. This paper seeks to develop a more accurate optimization model to inform risk-conscious investment decisions for bioenergy generation capacity in sugarcane mills. The main objective is for the model to enable a better understanding of how Brazilian government policies, such as the electricity price in the regulated market, may impact these investments, by taking into account the uncertainty in sugar, ethanol and spot electricity markets and the interdependency between production and investment decisions in terms of saleable product mix. The proposed methodology combines portfolio optimization theory with superstructure process modeling and it relies on simple surrogates derived from a detailed sugarcane plant simulator to retain computational tractability and enable scenario analysis. The case study of an existing sugarcane plant is used to demonstrate the methodology and illustrate how the model can assist decision-makers. In all of the scenarios assessed, the model recommends investment in extra bioelectricity capacity via the anaerobic digestion of vinasse but advises against investment in second-generation ethanol production via the hydrolysis of surplus bagasse. Furthermore, the decision to upgrade the cogeneration system with a condensation turbine is highly sensitive to the electricity price practiced in the regulated market, capacity constraints on the sugar-ethanol mix, and the accepted level of risk. Another key insight drawn from the case study is that recent market conditions have favored a production focused on the sugar business, making it challenging for policy-makers to create attractive scenarios for biofuels. Long-term electricity contracting appears to be the main hedging strategy for de-risking other products and investments in the sugarcane business, provided it is priced adequately

ENHANCING SUSTAINABLE PROCESS DESIGNS THROUGH STRATEGIC MATERIAL UTILIZATION AND WASTE MINIMIZATION APPROACHES

Sustainability is a growing concern as resources are continually depleted for various applications without adequate renewal plans. The resulting impacts on the ecosystem, health, and resource circularity are often overlooked. This research analyzes improvement opportunities at each major stage in a product\u27s life cycle. Raw material acquisition, product synthesis, process waste management, and the fate of a material in the end-of-life phases were examined. The viability of utilizing renewable resources has been demonstrated in this work by extracting bio-based chemicals from underutilized renewable resources at a commercial scale and transforming the extracted resources into polymeric materials. The optimization of raw material acquisition and process waste management have been accomplished via a superstructure-based approach that is modeled as MINLP optimization problem. Even though process sustainability can be achieved with strategic usage of renewable resources and recovery, the fate of post-consumer materials also poses major concerns regarding releases and emissions if left unmitigated. The guidelines surrounding the manufacturing and end-of-life phases of a material introduced in this work, backed by experimental and computational findings, can be used to effectively design environmentally conscious processes, inventions, and materials without sacrificing costs