A multiscale methodology for the preliminary screening of alternative process designs from a sustainability viewpoint adopting molecular and process simulation along with data envelopment analysis

La ricerca scientifica nell\u2019ambito dell\u2019ingegneria chimica si \ue8 focalizzata sia sul perfezionamento delle teorie e delle tecniche utilizzate attualmente, che sullo sviluppo di nuovi strumenti atti a risolvere le problematiche ancora insolute relative alle produzioni di beni e servizi tipici delle industrie chimiche, biochimiche e farmaceutiche. In questo panorama, gli approcci multiscala si sono rivelati molto utili grazie alla loro peculiarit\ue0 di coniugare aspetti che spaziano dalla quanto-meccanica tipica della nanoscala, alla meccanica classica dei materiali massivi, comprendendo prospettive molto ampie e adattando ogni teoria alle diverse applicazioni. Inoltre, il riconoscimento dei concetti legati alla sostenibilit\ue0 come principi cardine per ottenere uno sviluppo sostenibile ha generato un prolifico incremento della diffusione di metodologie per considerare aspetti sociali e ambientali, a fianco delle tradizionali stime economiche, nel quadro pi\uf9 ampio delle valutazioni degli impianti chimici. Di conseguenza, questa tesi tratta dello sviluppo di una metodologia multiscala per la stima preliminare di diverse configurazioni impiantistiche, promuovendo l\u2019adozione di strumenti computazionali differenti e comprendendo valutazioni di carattere economico, sociale e ambientale. Il fine ultimo che tale metodologia si prefigge risiede nella soddisfazione della necessit\ue0 tipica di qualsiasi impianto di produzione, ovvero nella definizione di una metodologia di valutazione di vari parametri e configurazioni impiantistiche, utilizzando un\u2019ottica sostenibile e fornendo risultati velocemente. Al lettore verranno fornite le adeguate informazioni sull\u2019argomento in maniera progressiva attraverso i capitoli di questa tesi. Nel Chapter I saranno descritti il concetto di sostenibilit\ue0 e di sviluppo sostenibile. Seguir\ue0 una trattazione riguardante la loro applicazione nella societ\ue0 odierna da diverse prospettive: a partire da quella pi\uf9 generalista delle istituzioni, fino a quella pi\uf9 particolare dell\u2019industria, per concludere con una parte specifica sull\u2019industria chimica, corredata di esempi di metodologie applicate a processi chimici. Il Chapter II descriver\ue0 i passaggi necessari ad ottenere la valutazione della sostenibilit\ue0 delle alternative impiantistiche. Dal reperimento delle informazioni necessarie, all\u2019implementazione dei modelli nei simulatori di processo, seguito dal calcolo degli indici rappresentativi dei pilastri della sostenibilit\ue0, i cui valori vengono successivamente valutati tramite un algoritmo matematico (DEA) per identificare la configurazione impiantistica ottimale. Infine \ue8 necessario analizzare le alternative inefficienti di modo da comprendere su quali variabili si debba intervenire per migliorarne le prestazioni attraverso una retrofit analisi. Il Chapter III affronter\ue0 l\u2019utilizzo di diverse tecniche di simulazione molecolare per la stima del coefficiente di ripartizione ottanolo-acqua (Kow), che \ue8 un propriet\ue0 fondamentale per il calcolo di alcuni indici utilizzati. Il lettore trover\ue0 alcuni casi di studio descritti nel Chapter IV. Il primo appartiene al ramo della farmaceutica e si occupa della produzione del pioglitazone cloridrato attraverso l\u2019utilizzo di diverse vie di sintesi appartenenti a numerosi brevetti. La seconda applicazione della metodologia riguarda l\u2019industria biochimica e ottimizza le condizioni operative di un reattore utilizzato per la produzione di biodiesel a partire da olio vegetale. L\u2019ultimo caso di studio esplora il mondo dei materiali nanostrutturati, valutando diversi parametri di reazione utilizzati per condurre la sintesi di CdSe quantum dot. L\u2019ultimo Chapter V conterr\ue0 le valutazioni conclusive e le prospettive future.Research activity in chemical engineering is focused on the refinement of theories and techniques employed for the development of new tools aiming at solving issues directly related to the generation of goods and services supplied by chemical, biochemical and pharmaceutical industries. In this context, multiscale approaches revealed to be very useful, since they embrace theories from quantum mechanics at the nanoscale to classical mechanics at the macroscale, contemplating wide perspectives and enabling the adaptation of each theory to an abundance of disparate applications. Furthermore, the acknowledgment of sustainability among the cornerstones of future development led to a copious diffusion of sustainability evaluation methodologies, aiming to account for economic, social and environmental concerns among chemical processes assessments. Therefore, this thesis deals with the development of a multiscale framework for the preliminary screening of chemical process designs, promoting the adoption of various computational tools along with sustainability considerations. The purpose of this methodology resides in the fulfillment of an emblematic need for any production site, i.e. evaluating a production process considering possible modifications from different perspectives in order to identify as fast as possible the most efficient design including economic, social and environmental concerns. The reader will be guided through this topic following the chapters of this dissertation. In Chapter I, the concept of sustainability and sustainable development will be presented, followed by some applications starting from the wider panorama of institutions to the industry perspective, concluding with some relevant examples from chemical process engineering. Chapter II will describe each step to be performed in order to gain the sustainability evaluation of the process alternatives. From retrieving the promising process designs, to implementing each flowsheet in a process simulator, then calculating several indicators based on the sustainability pillars, which is followed by employing a mathematical tool (DEA) in order to select the most efficient designs and finally investigating how to enhance the sub-optimal alternatives through a retrofit analysis. Chapter III will deal with the application of different molecular simulation techniques in order to estimate the octanol-water partition coefficient (Kow), which is an essential parameter for the calculation of several sustainability indicators. Then the reader will encounter the three case studies shown in details in Chapter IV. The first one belongs to the pharmaceutical field and deals with the production of pioglitazone hydrochloride considering different synthesis routes from various patents. The second application regards the biochemical industry, optimizing the operating conditions of a reactor employed for the production of biodiesel from vegetable oil. The last one explores the synthesis of nanomaterials, evaluating several reaction parameters involved in the laboratory production of CdSe quantum dots from a sustainability viewpoint. Some concluding remarks and future perspectives will be included in the final Chapter V

Molecular Characterisation of Fluidised Catalytic Cracker Feedstocks using Ruthenium Tetroxide Oxidation: a Study of Model Hydrocarbons

The world's proven reserves of crude oil will be depleted in 42 years at the current rate of consumption. Oil refiners are under considerable economic and environmental pressure to improve the efficiency of refining and the quality and definition of products. Statistical and fundamental models are extensively used to more accurately model the important refinery processes such as Fluidised Catalytic Cracking (FCC). A major problem with the fundamental approach is that FCC feedstocks are by definition heavy petroleum fractions, and as such constitute highly complex mixtures of aromatic and aliphatic hydrocarbons. Gas chromatography (GC) analysis of heavy petroleum fractions reveals a broad 'hump' of unresolved compounds termed an Unresolved Complex Mixture (UCM) of hydrocarbons. Conventional instrumental techniques alone are unable to elucidate the composition of UCMs, they are simply too complex. Oxidative degradation of UCMs has already been used with some success to selectively oxidise aliphatic and aromatic UCMs to reveal some of the structures incorporated in UCMs from various natural and anthropogenic sources. Ruthenium tetroxide (RUO4) attacks aromatic rings at the ipso-carbon of aromatic moieties. Unsubstituted aromatic carbon is oxidised to CO2 whereas substituents are preserved as carboxylic acids. "Retro-structural analysis" involves reconstruction of the products of oxidation to reveal the original molecule or 'average' molecule. However, previous studies have highlighted problems with the recovery of products from die oxidation of hydroaromatic compounds. Hydroaromatic compounds contain an alicyclic ring attached to an aromatic ring e.g. tetralin. This study presents evidence that (theoretically) data from RUO4 oxidation FCC feedstocks can make a significant improvement to the accuracy of FCC modelling at BP Amoco. RUO4 oxidation and work-up procedures were developed further in an attempt to overcome problems with 'losses' of oxidation products from hydroaromatic compounds, including an improved carbon dioxide trap. Several novel hydroaromatic compounds and a diaromatic compound proposed in a previous study as being 'average' UCM components were synthesised and fully characterised by GC, GCMS, FTIR and NMR spectroscopy. The compounds synthesised were 6-cyclohexyltetralin, l-(3'- methylbutyl)7-cyclohexyltetralin, 1-n-nonyl-7-cyclohexyltetralin and 1-/n-nonyl-7- cyclohexylnaphthalene. RUO4 oxidation of the synthetic compounds and commercial tetralin revealed that while losses of between 70 and 50% of the expected water soluble dicarboxylic acids are observed, these losses can be at least partially accounted for by the 'over oxidation' of carboxylic acids to produce smaller carboxylic acids. For example, the RUO4 oxidation of tetralin produces 1,6-hexanedioic acid as a major product but significant amounts of 1,5-pentanedioic acid is observed along with trace amounts of 1,4- butanedioic acid. Smaller acids are likely to be undetected or lost as butyl esters during the work-up. Where 2-n-nonyl-1,6-hexanedioic acid was produced, decanoic and nonanoic acid as well as 1,5- pentanedioic acid and 1,4-butanedioic acid were observed corresponding to oxidation of the 2- position on the dicarboxylic acid. The three major products from RUO4 oxidation of ln-nonyl-7-cyclohexylnaphthalene were partially oxidised compounds including 2-(l-oxo-n-decane)-4-cyclohexylbenzoic acid, showing that the oxidation of diaromatic compounds in UCMs gives more complex oxidation products. This is consistent with previous studies where diaromatic UCMs were oxidised to give a more complex 'oxidised UCM' rather than simple carboxylic acids. The observation of monocarboxylic acids in oxidation products from the alicyclic portion of a hydroaromatic compound has not previously been reported. This represents a new source of monocarboxylic acids in the RUO4 oxidation products of UCMs and should be taken into account when oxidising UCMs likely to contain a significant proportion of hydroaromatic structures, such as hydrotreated FCC feedstocks. The synthesis and oxidation of di-substituted teiralins has increased the understanding of RuG4 oxidation products from UCMs and consequently furthered the use of RUO4 as a potentially useftjl tool in the elucidation of FCC feedstock compositions and other aromatic UCMs

Morphometric study of horseshoe crab’s spawning population in a coastal area of peninsular Malaysia

Two Asian horseshoe crabs Tachypleus gigas and Carcinoscopius rotundicauda are commonly found on some coastal habitat in the east coast of Peninsular Malaysia during their spawning season. The number is small if compared to the Atlantic species, Limulus polyphemus which could be related to their foraging ground on sea bottom. It is not easy to ascertain the reason of the small landing population of horseshoe crab in the east coast of the Malay Peninsula. Some morphometric information on spawning population of horseshoe crab was studied at mangroves and sandy beach habitat in Balok coastal area of Pahang. Morphometric parameters measured in this study included body weight (Wt), inter-ocular length (IOL), dorsal prosoma breadth (DPB), dorsal body length (DBL), ventral prosoma breadth (VPB), telson length (TL), central height (CH), frontal length (FL), frontal margin height (FMH), and regional length (RL). Weight of T.gigas ranged from 290 to 1200g and 180 to 420g for female and male respectively while C. rotundicauda ranged from 260 to 340g and 100 to 260 for female and male respectively. Parameter with the highest mean value is weight. The lowest mean value was found for IOL with 88.64±6.62mm (male) and 120.42±9.95mm (female) and 62.87±14.39mm (female) and 77.0±6.57mm (male) for T.gigas and C. rotundicauda respectively. Statistically it was found that the males and females T. gigas could grow with the same rate in DPB and DBL. Nonetheless, male C. rotundicauda has the most increase of size of prosomal breadth in DPB than DBL. There was no evidence of imbalance growth of both sexes of the species collected from the study area. The findings indicate a good growth condition for both species. The relationship between the surrounding bottom habitat and the diet of horseshoe crab should be studied further to understand the contribution of sea bottom habitat to horseshoe crabs

Using chemical structure and inocula characteristics to predictively model biodegradation rate

PhD ThesisPredictive biodegradation models [i.e. Quantitative Structure Biodegradation Relationship (QSBR) models] might be used as an alternative to current regulatory biodegradation tests to predict chemical persistence. Current models are mostly based on the results derived from regulatory Ready Biodegradability Tests (RBTs), which are highly variable and were not designed to provide half-life data and therefore fundamentally undermines efforts to reliably predict chemical persistence. Improvement to existing approaches for developing and verifying predictive models and their reliability, respectively, have been proposed, and the use of functional gene and 16S rRNA amplicon sequencing techniques towards identifying and quantifying the putative chemical degraders have been studied. Several QSBR models for aromatic chemicals were developed according to OECD principles. Models for mono-aromatic chemicals were verified and calibrated with experimentally determined rates (both from pure culture and natural mixed communities). Traditional test methods were combined with functional genes and 16S amplicon sequence analyses to develop a relationship between rate, chemical concentration and competent putative chemical degrader abundance. QSBR models for mono-aromatic chemicals were stable (R2 = 0.8924), robust (Q2LOO = 0.8718) and had good predictive ability (Q2F1 = 0.8829, Q2F2 = 0.8835, and Q2F3 = 0.9178). In these models, biodegradation rates were associated with electronic, lipophilic and steric descriptors, and thus provided information on the mechanisms of different rate-limiting steps associated with the biodegradation process. However, all the variation in biodegradation rates cannot be explained by the structure alone, the prevailing environmental conditions have a significant role in determining the extent of chemical degradation. Biodegradation rates (k) of chemicals in natural mixed communities were significantly correlated with the ratio of abundance of initial putative degrader abundances (X0) and the starting chemical concentration (C0) (Pearson correlation coefficient (r) > 0.9 and p-value < 0.05). Predictive models developed by relating k with X0 and C0 reliably predicted the rate of studied chemicals. Experimentally determined rates further formed the basis towards calibrating the developed QSBR models. The molecular analysis revealed that majority of identified putative chemical degraders were rare taxa, and their enrichment did not necessarily influence the overall biomass count of the microbial community, and therefore biodegradation models that only consider the overall biomass would not account for the kind of relationships found in this study. Application of 16S amplicon sequencing and functional gene analyses techniques in biodegradation studies will help in depth screening of diversity and function of microbial community in an inoculum and enables better understanding of biodegradation outcomes.funded by the Engineering and Physical Sciences Research Counci

Biomimetic Based Applications

The interaction between cells, tissues and biomaterial surfaces are the highlights of the book "Biomimetic Based Applications". In this regard the effect of nanostructures and nanotopographies and their effect on the development of a new generation of biomaterials including advanced multifunctional scaffolds for tissue engineering are discussed. The 2 volumes contain articles that cover a wide spectrum of subject matter such as different aspects of the development of scaffolds and coatings with enhanced performance and bioactivity, including investigations of material surface-cell interactions

Cold Active Enzyme Booster Technology (EnBooT) for Biodegradation of P-Xylene

p-xylene is used as a solvent in medical technology, the leather, paint, and rubber industries. The principal pathway of human contact to p-xylene is via soil and groundwater contamination. Bioremediation offers potential advantages such as being cost-effective and environmentally friendly with lesser undue damage to environments. The main aim of this project is to find an enzyme mixture for biodegradation of p-xylene contaminated sites. In this regard, screening of indigenous bacteria, identification of involved enzymes, and biodegradation tests were carried out. The results showed that xylene monooxygenase (XMO) and catechol 2,3-dioxygenase (C2,3D) have a matching end product, they acted in symphony to degrade p-xylene. The mixture of these enzymes confirmed the complete degradation of p-xylene within 48 h in groundwater (initial concentration of 200 mg/L), 7 days in soil tests (initial concentration of 10,000 -12,000 mg/kg of soil) at 15°C, which is revolutionary for the industrial sector. In soil column tests, different concentrations of the enzyme mixture were used (1x, 5x, and 10x dilution). In this test, 92-94% p-xylene removal was achieved in the treated soil with a 5x diluted enzyme mixture (contained 10 U/mL of XMO and 20 U/mL of C2,3D). Our results showed that biodegradation is a scale-dependent phenomenon and the maximum degradation rate decreased from ~90% to 68% from the soil column to tank tests. It is due to limited access of enzymes to trapped p-xylene in soil pores, low dissolved oxygen, soil heterogeneity, and free phase contaminant. In addition, one of the major challenges in the practical and commercial application of these enzymes is their inherent instability. Our results showed that immobilization improved the stability of enzymes. For example, micro/nano biochar-chitosan matrices increased the stability of enzymes with more than 50% residual activity after 30 days at 4±1 ºC, while the free enzymes had less than 10% of its activity. Overall, this cold-active enzyme mixture can be applied for the biodegradation of all BTEX compounds (benzene, toluene, ethylbenzene, and xylenes). This study could set the guideline for the enzymatic bioremediation of mono-aromatic pollutants in contaminated soil and groundwater under cold conditions

Cold Active Enzyme Booster Technology (EnBooT) for Biodegradation of P-Xylene

p-xylene is used as a solvent in medical technology, the leather, paint, and rubber industries. The principal pathway of human contact to p-xylene is via soil and groundwater contamination. Bioremediation offers potential advantages such as being cost-effective and environmentally friendly with lesser undue damage to environments. The main aim of this project is to find an enzyme mixture for biodegradation of p-xylene contaminated sites. In this regard, screening of indigenous bacteria, identification of involved enzymes, and biodegradation tests were carried out. The results showed that xylene monooxygenase (XMO) and catechol 2,3-dioxygenase (C2,3D) have a matching end product, they acted in symphony to degrade p-xylene. The mixture of these enzymes confirmed the complete degradation of p-xylene within 48 h in groundwater (initial concentration of 200 mg/L), 7 days in soil tests (initial concentration of 10,000 -12,000 mg/kg of soil) at 15C, which is revolutionary for the industrial sector. In soil column tests, different concentrations of the enzyme mixture were used (1x, 5x, and 10x dilution). In this test, 92-94% p-xylene removal was achieved in the treated soil with a 5x diluted enzyme mixture (contained 10 U/mL of XMO and 20 U/mL of C2,3D). Our results showed that biodegradation is a scale-dependent phenomenon and the maximum degradation rate decreased from ~90% to 68% from the soil column to tank tests. It is due to limited access of enzymes to trapped p-xylene in soil pores, low dissolved oxygen, soil heterogeneity, and free phase contaminant. In addition, one of the major challenges in the practical and commercial application of these enzymes is their inherent instability. Our results showed that immobilization improved the stability of enzymes. For example, micro/nano biochar-chitosan matrices increased the stability of enzymes with more than 50% residual activity after 30 days at 41 C, while the free enzymes had less than 10% of its activity. Overall, this cold-active enzyme mixture can be applied for the biodegradation of all BTEX compounds (benzene, toluene, ethylbenzene, and xylenes). This study could set the guideline for the enzymatic bioremediation of mono-aromatic pollutants in contaminated soil and groundwater under cold conditions

Laboratory directed research development annual report. Fiscal year 1996

This document comprises Pacific Northwest National Laboratory`s report for Fiscal Year 1996 on research and development programs. The document contains 161 project summaries in 16 areas of research and development. The 16 areas of research and development reported on are: atmospheric sciences, biotechnology, chemical instrumentation and analysis, computer and information science, ecological science, electronics and sensors, health protection and dosimetry, hydrological and geologic sciences, marine sciences, materials science and engineering, molecular science, process science and engineering, risk and safety analysis, socio-technical systems analysis, statistics and applied mathematics, and thermal and energy systems. In addition, this report provides an overview of the research and development program, program management, program funding, and Fiscal Year 1997 projects

Antioxidant and DPPH-Scavenging Activities of Compounds and Ethanolic Extract of the Leaf and Twigs of Caesalpinia bonduc L. Roxb.

Antioxidant effects of ethanolic extract of Caesalpinia bonduc and its isolated bioactive compounds were evaluated in vitro. The compounds included two new cassanediterpenes, 1α,7α-diacetoxy-5α,6β-dihydroxyl-cass-14(15)-epoxy-16,12-olide (1)and 12α-ethoxyl-1α,14β-diacetoxy-2α,5α-dihydroxyl cass-13(15)-en-16,12-olide(2); and others, bonducellin (3), 7,4’-dihydroxy-3,11-dehydrohomoisoflavanone (4), daucosterol (5), luteolin (6), quercetin-3-methyl ether (7) and kaempferol-3-O-α-L-rhamnopyranosyl-(1Ç2)-β-D-xylopyranoside (8). The antioxidant properties of the extract and compounds were assessed by the measurement of the total phenolic content, ascorbic acid content, total antioxidant capacity and 1-1-diphenyl-2-picryl hydrazyl (DPPH) and hydrogen peroxide radicals scavenging activities.Compounds 3, 6, 7 and ethanolic extract had DPPH scavenging activities with IC50 values of 186, 75, 17 and 102 μg/ml respectively when compared to vitamin C with 15 μg/ml. On the other hand, no significant results were obtained for hydrogen peroxide radical. In addition, compound 7 has the highest phenolic content of 0.81±0.01 mg/ml of gallic acid equivalent while compound 8 showed the highest total antioxidant capacity with 254.31±3.54 and 199.82±2.78 μg/ml gallic and ascorbic acid equivalent respectively. Compound 4 and ethanolic extract showed a high ascorbic acid content of 2.26±0.01 and 6.78±0.03 mg/ml respectively.The results obtained showed the antioxidant activity of the ethanolic extract of C. bonduc and deduced that this activity was mediated by its isolated bioactive compounds