Peter Mathias Harper

A multi-step and multi-level approach for computer aided molecular design

Abstract A general multi-step approach for setting up, solving and solution analysis of computer aided molecular design (CAMD) problems is presented. The approach differs from previous work within the field of CAMD since it also addresses the need for a computer aided problem formulation and result analysis. The problem formulation step incorporates a knowledge base for the identification and setup of the design criteria. Candidate compounds are identified using a multi-level generate and test CAMD solution algorithm capable of designing molecules having a high level of molecular detail. A post solution step for result analysis and verification is included in the methodology.

Design of environmentally benign processes: integration of solvent design and separation process synthesis

Abstract This paper presents a hybrid method for design of environmentally benign processes. The hybrid method integrates mathematical modelling with heuristic approaches to solving the optimisation problems related to separation process synthesis and solvent design and selection. A structured method of solution, which employs thermodynamic insights to reduce the complexity and size of the mathematical problem by eliminating redundant alternatives, has been developed for the hybrid method. Separation process synthesis and design problems related to the removal of a chemical species from process streams because of environmental constraints are particularly suited for solution with the hybrid method. Application of the hybrid method is highlighted through two illustrative examples. The first example involves the determination of an optimal flowsheet for the removal of a chemical species from an azeotropic mixture and the second example involves the determination of environmentally benign substitute solvents for removal of a chemical species from wastewater.

Computer aided molecular design with combined molecular modeling and group contribution

Computer-aided molecular design (CAMD) provides a means for determining molecules or mixtures of molecules (CAMMD) having a desirable set of physicochemical properties. The application range of CAMD is restricted due to limitations on the complexity of the generated molecular structures and on the availability of suitable models for property prediction. A new CAMD methodology that addresses this issue by combining molecular modeling techniques with a traditional CAMD approach is presented. The new method includes a new molecular/atomic structure generation algorithm, a large collection of property estimation methods, and, a link to molecular modelling tools. Application of the new CAMD method is highlighted through two industrial examples.

Chapter 6 – A Hybrid CAMD Method

This chapter describes a framework for a hybrid computer-aided molecular design (CAMD) method. The design process, according to this framework is divided into the following three phases: (1) the pre-design phase, definition phase of the CAMD problem, (2) the design phase, solution phase of the CAMD problem in terms of generation of feasible candidates, and (3) the post-design phase, analysis phase of the CAMD where the final selection is made. The chapter presents the principal ideas behind this framework through a simple CAMD problem, where functional groups are used as the building blocks, for generating feasible molecular structures. The chapter also highlights the architecture of such a hybrid CAMD method. The design process starts with a definition of the basic needs (or ultimate goals). The type of goal may influence many of the design decisions that will need to be made during the later phases of the CAMD problem solution. The goal should describe the function of the desired chemical product, the environment/equipment, where the function should be performed, as well as the capabilities that are desirable/undesirable. The hybrid CAMD method described employs successive generate and test approaches ordered in a hierarchy based on the level of molecular structural information used and the corresponding property estimation method. The chapter also discusses knowledge base, problem formulation algorithm, generation algorithm for level 1, and others.

Computer Aided Product Design and Pollution Prevention Through Substitution

Computer aided molecular design provides a means for determining molecules or mixtures of molecules (CAMD) having a desirable set of physico-chemical properties. Therefore, it is ideally suited for selection/design of material substitutes in the prevention and/or cure of some pollution problems. Even though CAMD has found useful industrial applications, the application range is restricted because of the limitations on the complexity of the generated molecular structures and on the availability of suitable models for property prediction. In this paper we have combined molecular-level information with the current group contribution based methods in order to open new horizons of applicability and accuracy of CAMD. With our new integrated approach, we have a multi-level method for molecular structure generation and property prediction. The first two levels are macroscopic, while the third and fourth levels are microscopic. The purpose of adding the microscopic representation is that it allows a more thorough analysis of the generated molecules and it provides an interactive feature for generating structural alternatives. With this combined approach, it is now possible to apply CAMD for a large range of problems involving pollution prevention by substitution. Through a case study involving several sub-problems, application of CAMD for solution of typical problems in pollution prevention by substitution is highlighted.

An integrated environment for batch process development — from recipe to manufacture

Publisher Summary Batch-process development involves the process of converting a chemical synthesis into an optimum, safe, robust, and economical process for manufacturing the chemical of desired quality at the ultimate desired scale. This chapter describes a strategy for developing a set of integrated decision support tools to facilitate this activity. The primary motivator for doing this is to perform fast and high-quality process development, because there is significant economic leverage that can be gained by speeding up this activity while not compromising on quality. The application of the strategy to an industrial case study is also presented. The batch-process development pipeline can be viewed as consisting of the following aspects: process alternatives synthesis, process alternatives evaluation, process operations development, and process operations assessment. This method minimizes rework by avoiding multiple problem setups, thereby allowing faster process development. The quality of the development activity is also enhanced through the sharing of the function across the different tools.

Computer aided technique for pollution prevention and treatment

Abstract A framework for the identification of environmentally benign and alternative solvents is presented. The methodology for solvent design and selection contains multiple stages: 1. problem formulation, 2. constraint selection, 3. candidate identification, 4. verification and final selection. The candidate identification step can be performed using a database search method or a Computer Aided Molecular Design (CAMD) approach. A multi level CAMD method capable of generating a selection of candidates meeting the required specification without suffering from combinatorial explosion is presented and the entire framework is illustrated with a case study. The case study identifies alternative solvents for Oleic acid methyl ester as replacements for Ethyl ether and Chloroform.

ENVIRONMENTAL IMPACT ASSESSMENT: AN OVERVIEW OF METHOD TYPES AND KEY FACTORS

An overview of the field of Environmental Impact Assessment is presented. The different types of methods considered in this overview are presented and their key terms and traits are identified. The role of impact assessment in various applications is discussed, along with identification of key questions and issues that need to be addressed.