Jhuma Sadhukhan

Biorefineries and Chemical Processes: Design, Integration and Sustainability Analysis

As the range of feedstocks, process technologies and products expand, biorefineries will become increasingly complex manufacturing systems. Biorefineries and Chemical Processes: Design, Integration and Sustainability Analysis presents process modelling and integration, and whole system life cycle analysis tools for the synthesis, design, operation and sustainable development of biorefinery and chemical processes. Topics covered include: Introduction: An introduction to the concept and development of biorefineries. Tools: Included here are the methods for detailed economic and environmental impact analyses; combined economic value and environmental impact analysis; life cycle assessment (LCA); multi-criteria analysis; heat integration and utility system design; mathematical programming based optimization and genetic algorithms. Process synthesis and design: Focuses on modern unit operations and innovative process flowsheets. Discusses thermochemical and biochemical processing of biomass, production of chemicals and polymers from biomass, and processes for carbon dioxide capture. Biorefinery systems: Presents biorefinery process synthesis using whole system analysis. Discusses bio-oil and algae biorefineries, integrated fuel cells and renewables, and heterogeneous catalytic reactors. Companion website: Four case studies, additional exercises and examples are available online, together with three supplementary chapters which address waste and emission minimization, energy storage and control systems, and the optimization and reuse of water. This textbook is designed to bridge a gap between engineering design and sustainability assessment, for advanced students and practicing process designers and engineers.

Novel integrated mechanical biological chemical treatment (MBCT) systems for the production of levulinic acid from fraction of municipal solid waste: A comprehensive techno-economic analysis.

This paper, for the first time, reports integrated conceptual MBCT/biorefinery systems for unlocking the value of organics in municipal solid waste (MSW) through the production of levulinic acid (LA by 5wt%) that increases the economic margin by 110-150%. After mechanical separation recovering recyclables, metals (iron, aluminium, copper) and refuse derived fuel (RDF), lignocelluloses from remaining MSW are extracted by supercritical-water for chemical valorisation, comprising hydrolysis in 2wt% dilute H2SO4 catalyst producing LA, furfural, formic acid (FA), via C5/C6 sugar extraction, in plug flow (210-230°C, 25bar, 12s) and continuous stirred tank (195-215°C, 14bar, 20min) reactors; char separation and LA extraction/purification by methyl isobutyl ketone solvent; acid/solvent and by-product recovery. The by-product and pulping effluents are anaerobically digested into biogas and fertiliser. Produced biogas (6.4MWh/t), RDF (5.4MWh/t), char (4.5MWh/t) are combusted, heat recovered into steam generation in boiler (efficiency: 80%); on-site heat/steam demand is met; balance of steam is expanded into electricity in steam turbines (efficiency: 35%).

A small-scale transdisciplinary process to maximising the energy efficiency of food factories: insights and recommendations from the development of a novel heat integration framework

The rise and uncertainty in energy prices in recent years has widened the solution search space by industry to understand the full impacts on operations and to develop a range of workable solutions to reduce risk. This has involved companies exploring alternative approaches to co-create solutions with different groups comprising varying intellectual capital, e.g. consultants, NGOs, and academia. This paper presents the small-scale transdisciplinary process adopted by Nestlé UK in partnership with the University of Surrey as part of an Engineering Doctorate (EngD) programme to co-develop a heat integration framework to improve the energy efficiency of a confectionery factory. The small-scale co-creation process—between industry and academia—for a heat integration framework is described and includes a set of criteria to evaluate the effectiveness of the process. The results of the evaluation process and a reflection of the key challenges and implications faced when trying to implement a small-scale transdisciplinary process are reported which covers the role of an EngD researcher as a manager, facilitator and researcher, time management, finance, communication, knowledge integration, mutual learning, and conflict. Some of the key recommendations for industrial practitioners include: actively engaging in the transdisciplinary process on a consistent basis, staying open minded to developing a solution even when there is a lack of progress, and building relationships with academics by supporting university activities, e.g. lecturing, research projects and funding proposals. For scientists, PhD students, research institutes, and private and public R&D, some of the key recommendations include: communicating expert knowledge to a few points rather than opening out into a lecture, contributing to the transdisciplinary process even if it is on a non-expert level but provides objective and critical input, and visiting industrial sites to gain exposure to industrial problems first-hand. Overall, the range of recommendations provided can help both industrial practitioners and scientists, especially doctoral students seeking to operate in the industry–academia domain on a small—practically manageable—scale.

A multi-criteria decision support framework for sustainable asset management and challenges in its application

Despite an increasing demand for considering sustainability aspects in asset management, there is a lack of guidance for decision-makers on how this can be achieved. The aim of this research is to present rational decision support for sustainable management of industrial assets in situations where there are multiple conflicting objectives. For this purpose, a Multi-criteria decision analysis framework that incorporates sustainability criteria over the whole life cycle has been developed. Stakeholder participation and uncertainty assessment are considered explicitly allowing for a holistic perspective and higher confidence in the results. In order to facilitate communication, methods for visualization of numerical results are highlighted. While the focus of this study is on the development of the framework, the challenges of applying it and potential steps to address these are discussed through an application in the shipping sector.

Multi-objective optimisation of metabolic productivity and thermodynamic performance

Novel multi-objective optimisation methodologies, including a two-step sequential optimisation approach and multi-objective optimisation approaches using non-dominated sorting genetic algorithms (NSGAs) and MATLAB based linear programming integrated with genetic algorithms have been developed for the first time to engineer the cellular metabolic productivity and process performance simultaneously. The simultaneous optimisation of cellular metabolic productivity and thermodynamic performance deduces a unique set of enzyme catalysed pathways and flux distributions for a given metabolic product of importance. It has been demonstrated that the energy generating pathways associated to drive a desired productivity are prioritised effectively by multi-objective optimisation approach. A case study on the pentose phosphate pathway (PPP) and glycolysis of in silico Escherichia coli has been used to illustrate the effectiveness of the methodologies.

Life cycle, techno-economic and dynamic simulation assessment of bioelectrochemical systems: A case of formic acid synthesis

A novel framework, integrating dynamic simulation (DS), life cycle assessment (LCA) and techno-economic assessment (TEA) of a bioelectrochemical system (BES), has been developed to study for the first time wastewater treatment by removal of chemical oxygen demand (COD) by oxidation in anode and thereby harvesting electron and proton for carbon dioxide reduction reaction or reuse to produce products in cathode. Increases in initial COD and applied potential increase COD removal and production (in this case formic acid) rates. DS correlations are used in LCA and TEA for holistic performance analyses. The cost of production of HCOOH is €0.015-0.005 g-1 for its production rate of 0.094-0.26 kg yr-1 and a COD removal rate of 0.038-0.106 kg yr-1. The life cycle (LC) benefits by avoiding fossil-based formic acid production (93%) and electricity for wastewater treatment (12%) outweigh LC costs of operation and assemblage of BES (-5%), giving a net 61MJkg-1 HCOOH saving.

Synthesis of industrial systems based on value analysis

In this contribution, we present a novel methodology for flexible design of industrial systems based on their detailed differential value analysis. Evolving from graph theory, this methodology devises a mechanism for systematic structural decomposition of large-scale industrial systems into basic processing elements (paths and trees), combination of elements into subsystems and evaluation of individual elements/subsystems to correlate with the overall system margin. This helps to reduce the size of the large combinatorial problems and comprehensively analyse the multiple objectives and the sets of optimal operating states, capital investments and marginal contributions at elemental/subsystems levels that are critical for flexible designs. The approach generates the whole set of optimal solutions compared to the one point solution of the deterministic approaches (MINLP) while allowing additional complexity of process level models in the site-wide integration due to the systematic structural decomposition of a system into its basic elements/subsystems. A recent industrial application on oil upgrading system design is used to illustrate the methodology.

Multiscale modelling of heterogeneously catalysed transesterification reaction process: an overview

Biodiesel is fast becoming one of the key transport fuels as the world endeavours to reduce its carbon footprint and find viable alternatives to oil derived fuels. Research in the field is currently focusing on more efficient ways to produce biodiesel, with the most promising avenue of research looking into the use of heterogeneous catalysis. This article presents a framework for kinetic reaction and diffusive transport modelling of the heterogeneously catalysed transesterification of triglycerides into fatty acid methyl esters (FAMEs), unveiled by a model system of tributyrin transesterification in the presence of MgO catalysts. In particular, the paper makes recommendations on multicomponent diffusion calculations such as the diffusion coefficients and molar fluxes from infinite dilution diffusion coefficients using the Wilke and Chang correlation, intrinsic reaction kinetic studies using the Eley–Rideal kinetic mechanism with methanol adsorption as the rate determining steps and multiscale reaction-diffusion process simulation between catalytic porous and bulk reactor scales.

A graphical CO2 emission treatment intensity assessment for energy and economic analyses of integrated decarbonised production systems

a b s t r a c t Design of clean energy systems is highly complex due to the existence of a variety of CO2 abatement and integration options. In this study, an effective decision-making methodology has been developed for facilitating the selection of lowest energy or lowest cost intensity systems, from a portfolio of flow- sheet configurations with different decarbonisation strategies. The fundamental aspect of the proposed methodology lies in thermodynamic feasibility assessment as well as quantification of CO2 emission treatment intensity using a graphical approach (CO2 emission balance diagram) for energy and economic performance analyses of integrated decarbonised systems. The relationship between the graphical rep- resentation and performances is established using blocks and boundaries on integrated systems. The effectiveness of the methodology has been demonstrated through a range of coal gasification based poly- generation and cogeneration systems, incorporating either of carbon capture and storage (CCS) or CO2 reuse options.

Material Flow and Sustainability Analyses of Biorefining of Municipal Solid Waste

This paper presents material flow and sustainability analyses of novel mechanical biological chemical treatment system for complete valorization of municipal solid waste (MSW). It integrates material recovery facility (MRF); pulping, chemical conversion; effluent treatment plant (ETP), anaerobic digestion (AD); and combined heat and power (CHP) systems producing end products: recyclables (24.9% by mass of MSW), metals (2.7%), fibre (1.5%); levulinic acid (7.4%); recyclable water (14.7%), fertiliser (8.3%); and electricity (0.126MWh/t MSW), respectively. Refuse derived fuel (RDF) and non-recyclable other waste, char and biogas from MRF, chemical conversion and AD systems, respectively, are energy recovered in the CHP system. Levulinic acid gives profitability independent of subsidies; MSW priced at 50Euro/t gives a margin of 204Euro/t. Global warming potential savings are 2.4 and 1.3kg CO2 equivalent per kg of levulinic acid and fertiliser, and 0.17kg CO2 equivalent per MJ of grid electricity offset, respectively.