O texto da Constituição da República Federativa do Brasil de 1988 teve o mérito de contemplar uma série de valores que, conquanto mencionados pela doutrina anteriormente, ganharam a força de princípios constitucionais orientadores das funções do Estado e do exercício das atividades de Governo. Dentre esses princípios, destaca-se a moralidade administrativa, que erigiu a nível constitucional a lisura da conduta dos agentes públicos, impondo-lhes a obediência, no exercício de suas funções, a valores morais juridicizados, norteados pela boa-fé, pela honestidade, pelo decoro, pela ética e pela lealdade. Em que pesem tais previsões constitucionais, vê-se, na realidade fática, um cenário de corrupção endêmica e de descrédito na honestidade das instituições pátrias. Diante desse contexto, urge que emerja da consciência cidadã o pilar ético da vida pública. Para tanto, propõe-se a ampla participação popular no controle da Administração Pública e da moralidade administrativa. Dentre os legítimos instrumentos de exercício da cidadania, destaca-se a ação popular, que permite a qualquer cidadão a defesa do patrimônio público em sentido amplo, abarcando a sua dimensão material e pecuniária (erário) e a sua dimensão imaterial (valores e princípios do Estado). Espera-se, destarte, que com o necessário investimento na educação, seguido da consequente e natural evolução da democracia, atinja-se um cenário de forte atuação do povo no contexto político, mobilizando-se em prol dos interesses sociais e da realização plena dos objetivos do Estado, insculpidos no texto constitucional. / The text of the Constitution of the Federative Republic of Brazil in 1988 had the merit of contemplating a series of values that, although mentioned by the doctrine previously, won the strength of guiding constitutional principles of state functions and the exercise of government activities. Among these principles, there is the administrative morality, which raised to constitutional level the righteousness of conduct of public officials, requiring them obedience, in the exercise of its functions, to the legal moral values, guided by good faith, honesty, decorum, ethics and loyalty. In spite of such constitutional provisions, it is seen, in objective reality, an endemic corruption scenario and discredit in the honesty of the institutions of the State. In this context, it is urgent that from citizen awareness emerges the ethical pillar of public life. To this end, we propose the broad popular participation in the control of public administration and administrative morality. Among the legitimate tools of citizenship, there is the class action, which allows any citizen to defend public assets in a broad sense, encompassing its material and pecuniary dimension (public funds) and its immaterial dimension (values and principles of State). We hope that with the necessary investment in education, followed by consistent and natural evolution of democracy, a scenario of strong popular participation strikes up in the political context, mobilizing in support of social interests and the full achievement of state goals, sculptured in the Constitution.

O trabalho foi desenvolvido dentro da linha de pesquisa da área de Direito do Trabalho, da Faculdade de Direito da Universidade de São Paulo Direitos sociais no contexto dos direitos humanos, visando uma hermenêutica apropriada para a realização dos direitos sociais trabalhistas. A Constituição da República Federativa do Brasil (1988) fez incluir os direitos sociais trabalhistas no Título II Dos Direitos e Garantias Fundamentais. Neste contexto, a problemática que se apresenta é a da efetividade das normas trabalhistas. Com base nas doutrinas de Robert Alexy e Gustavo Zagrebelsky, adotou-se a proposta de uma hermenêutica concretizadora, que reconheça a força normativa da Constituição, partindo-se da premissa de que os princípios constitucionais são normas de suporte fático amplo. Na perspectiva dos direitos humanos fundamentais, considerou-se a prevalência dos direitos sociais como pressuposto de um Estado Social, e para a construção de uma sociedade livre, justa e solidária um dos objetivos fundamentais da República Federativa do Brasil. A título de argumentação fez-se o estudo de decisões pautadas na teoria dos princípios, aproximando a doutrina da prática jurisdicional, demonstrando-se algumas possibilidades conferidas por uma hermenêutica concretizadora dos direitos humanos fundamentais e a viabilidade da efetividade dos direitos sociais trabalhistas. / Il lavoro fu svolto nellambito della linea di ricerca dellarea di Diritto del Lavoro della Facoltà di Diritto dellUniversità di São Paulo Diritti sociali nel contesto dei diritti umani, puntando su unermeneutica appropriata allattuazione dei diritti sociali del lavoro. La Costituzione della Repubblica Federativa del Brasile (1988) fece inserire i diritti sociali del lavoro nel Titolo II Diritti e Garanzie Fondamentali. In tale contesto, la problematica che si presenta è quella delleffettività delle norme del lavoro. In base alle dottrine di Robert Alexy e Gustavo Zagrebelsky, si adottò la proposta di unermeneutica attuativa, che riconosca la forza normativa della Costituzione, muovendo dalla premessa secondo cui i principi costituzionali sono norme di ampio supporto fattuale. Nella prospettiva dei diritti umani fondamentali, si tenne presente la prevalenza dei diritti sociali come presupposto di uno Stato Sociale e per la costruzione di una società libera, giusta e solidade uno degli scopi fondamentali della Repubblica Federativa del Brasile. A titolo di argomentazione si esaminò le decisioni fondate sulla teoria dei principi, avvicinando la dottrina alla pratica giurisdizionale, dimostrandosi alcune possibilità date da unermeneutica attuativa dei diritti umani fondamentali e la fattibilità delleffettività dei diritti sociali del lavoro.

La tesi di dottorato mira ad indagare la formazione e lo sviluppo del concetto di Repubblica nell’ordinamento costituzionale italiano. A tal fine viene presa in considerazione l’innovazione apportata dalla Costituzione repubblicana rispetto all’esperienza dello Stato moderno e si riscontra una forte connessione tra il concetto di Repubblica e la volontà politica di creare, nel secondo dopoguerra, un ordinamento che superi la tradizionale separazione tra Stato e società. Nella vigente Costituzione italiana ciò si traduce nel riconoscimento di un rilievo giuspubblicistico ad un ampio pluralismo sociale e nella creazione di uno Stato-ordinamento comprensivo tanto dello Stato-apparato quanto dello Stato-comunità. Il lavoro prosegue analizzando l’attualità del concetto di Repubblica in un contesto di rapporti sociali profondamente mutati rispetto al secondo dopoguerra ed in cui è il medesimo concetto di Stato ad essere oggetto di tensione. In questa prospettiva la forma repubblicana diviene la principale manifestazione di un principio unitario interno alla Costituzione, principio che viene declinato tanto a livello di ordinamento normativo quanto in relazione ai rapporti tra Stato e società. / The PhD thesis aims to inquire birth and growth of the Republic notion in the Italian constitutional system. The author assesses the innovation of the Italian republican Constitution compared to the whole experience of modern State and points out connections between the notion of Republic and the political will to create, after Second World War, a system which can overcome any distinction between State and society. The Italian Constitution implements this pattern giving a public position to a social pluralism and creating system including the state apparatus and the entire social community. Then, the thesis inquires the nowadays operation of the Republic notion with respect to social changes and state evolution. In this regard, the republican system is the main consequence of a principle of unity provided by the Constitution; this principle acts both in the normative order and in the relations between state and society.

L’obiettivo della ricerca è valorizzare il senso delle comunità per minori oggi come dispositivo adatto all’accoglienza, alla luce delle evoluzioni legislative in Italia. Il lavoro di tesi si svilupperà intorno ai seguenti temi: I. ricostruzione storica dei servizi educativi, dei servizi sociali, con riferimento al quadro legislativo; II. analisi dell’attuale differenziazione delle comunità per minori attraverso la lettura del monitoraggio effettuato dall’Istituto degli Innocenti di Firenze (2009); III. rilettura pedagogica dello strumento di comunità attraverso la valenza formativa del dispositivo; IV. ricerca di un “modello base”: una mappa di possibili principi per consentire una risposta unitaria e convincente all’allontanamento dei minori. / The purpose of this research project is to underline the sense of educative communities for younger people today as a tool suitable for the reception, taking into account all the legislative evolutions in Italy. In this thesis work the attention will be focused on the following topics: I. historical reconstruction of educative services and social services, with a reference to the legislative scenario; II. analysis of the current educative communities differentiation through the analysis of the monitoring realised by the “Institutes of the Innocents” in Florence (2009); III. pedagogical re-reading of the community framework thought the “device”’s formative merit; IV. research on a “base model”: a map of possible principles for a persuasive answer to the younger removals.

O presente estudo busca definir e afirmar o princípio da autorresponsabilidade como norma constitucional, decorrente do modelo de Estado Democrático de Direito, e, a partir daí, considerando o sistema de vinculação normativa propugnado pelo Estado Constitucional de Direito, avaliar criticamente a legitimidade da atuação paternalista estatal por meio do poder punitivo penal. Para tanto, primeiramente, busca-se traçar os parâmetros básicos do sistema jurídico-normativo, por meio de breves considerações acerca da teoria dos princípios. Em seguida, o objetivo é analisar a evolução do modelo de Estado, chegando-se ao atual Estado Constitucional e Democrático de Direito, desenhando-se a forma como se coloca a relação entre Estado, Constituição e Direito Penal. No momento seguinte, parte-se, propriamente, para a afirmação e definição do princípio constitucional da autorresponsabilidade, inerente à adoção do modelo de Estado Democrático de Direito. Por fim, com amparo no modelo de Estado Constitucional de Direito, será estudado o impacto da aplicação do princípio da autorresponsabilidade no Direito Penal, começando-se pela análise dos tipos penais paternalistas, passando-se pela teoria do consentimento, e chegando-se à teoria da imputação do resultado. / Il presente studio mira a definire e sostenere il principio dellautoresponsabilità come norma costituzionale derivata dal modello dello Stato Democratico di Diritto, e, a partire da ciò, valutare criticamente la legittimità dellazione paternalista statale mediante il potere punitivo penale, considerando il sistema di vincolazione normativa propugnato dallo Stato Costituzionale di Diritto. A questo fine, in primo luogo si cercherà di tracciare i parametri di base del sistema giuridico-normativo tramite brevi considerazioni circa la teoria dei principi. Successivamente, lobbiettivo sarà quello di analizzare levoluzione del modello di Stato, per arrivare allattuale Stato Democratico Costiruzionale di Diritto, illustrando la relazione tra lo Stato, la Costituzione e il Diritto Penale. In seguito, ci si occuperà propriamente dellaffermazione e della definizione del principio costituzionale dellautoresponsabilità, inerente alladozione del modello di Stato Democratico di Diritto. Infine, in base al modello di Stato Costituzionale di Diritto, si studierà limpatto dellapplicazione del principio dellautoresponsabilità sul Diritto Penale, cominciando con lanalisi di fattispecie penali paternalistiche, passando poi alla teoria del consenso e arrivando per ultimo alla teoria dellimputazione dellevento.

Durant els darrers quaranta anys la geometria diferencial ha estat una eina fonamental per entendre la teoria de control òptim. Habitualment la millor estratègia per resoldre un problema és transformar-lo en un altre problema que sigui més tractable. El Principi del Màxim de Pontryagin proporciona al problema de control òptim d’una estructura Hamiltoniana. Les solucions del problema Hamiltonià que satisfan unes determinades propietats són candidates a ésser solucions del problema de control òptim. Aquestes corbes candidates reben el nom d’extremals. Per tant, el Principi del Màxim de Pontryagin aixeca el problema original a l’espai cotangent. En aquesta tesi desenvolupem una demostració completa i geomètrica del Principi del Màxim de Pontryagin. Investiguem cuidadosament els punts més delicats de la demostració, que per exemple inclouen les perturbacions del controls, l’aproximació lineal del conjunt de punts accessibles i la condició de separació. Entre totes les solucions d’un problema de control òptim, existeixen les corbes anormals. Aquestes corbes no depenen de la funció de cost que es vol minimitzar, sinó que només depenen de la geometria del sistema de control. En la literatura de control òptim, existeixen estudis sobre l’anormalitat, tot i que només per a sistemes lineals o afins en el controls i sobretot amb funcions de cost quadràtiques en els controls. Nosaltres descrivim un mètode geomètric nou per caracteritzar tots els diferents tipus d’extremals (no només les anormals) de problemes de control òptim genèrics. Aquest mètode s’obté com una adaptació d’un algoritme de lligadures presimplèctic. El nostre interès en les corbes anormals es degut a les corbes òptimes estrictament anormals, les quals també queden caracteritzades mitjançant l’algoritme descrit en aquesta tesi. Com aplicació del mètode mencionat, caracteritzem les extremals d’un problema de control òptim lliure, aquell on el domini de definició no està donat. En concret, els problemes de temps mínim són problemes de control òptim lliures. A més a més, som capaços de donar una corba extremal estrictament anormal aplicant el mètode descrit per a un sistema mecànic. Un cop la noció d’anormalitat ha estat estudiada en general, ens concentrem en l’estudi de l’anormalitat per a sistemes de control mecànics, perquè no existeixen resultats sobre l’existència de corbes òptimes estrictament anormals per a problemes de control òptim associats a aquests sistemes. En aquesta tesi es donen resultats sobre les extremals anormals quan la funció de cost és quadràtica en els controls o si el funcional a minimitzar és el temps. A més a més, la caracterització d’anormals en casos particulars és descrita mitjançant elements geomètrics com les formes quadràtiques vector valorades. Aquests elements geomètrics apareixen com a resultat d’aplicar el mètode descrit en aquesta tesi. També tractem un altre enfocament de l’estudi de l’anormalitat de sistemes de control mecànics, que consisteix a aprofitar l’equivalència que existeix entre els sistemes de control noholònoms i els sistemes de control cinemàtics. Provem l’equivalència entre els problemes de control òptim associats a ambdós sistemes de control i això permet establir relacions entre les corbes extremals del problema nonholònom i del cinemàtic. Aquestes relacions permeten donar un example d’una corba òptima estrictament anormal en un problema de temps mínim per a sistemes de control mecànics. Finalment, i deixant de banda per un moment l’anormalitat, donem una formulació geomètrica dels problemes de control òptim no autònoms mitjançant la formulació unificada de Skinner-Rusk. La formulació descrita en aquesta tesis és fins i tot aplicable a sistemes de control implícits que apareixen en un gran nombre de problemes de control òptim dins de l’àmbit de l’enginyeria, com per exemple els sistemes Lagrangians controlats i els sistemes descriptors. / Durante los últimos cuarenta años la geometría diferencial ha sido una herramienta para entender la teoría de control óptimo. Habitualmente la mejor estrategia para resolver un problema es transformarlo en otro problema que sea más tratable. El Principio del Máximo de Pontryagin dota al problema de control óptimo de una estructura Hamiltoniana. Las soluciones del problema Hamiltoniano que satisfagan determinadas propiedades son candidatas a ser soluciones del problema de control óptimo. Estas curvas candidatas se llaman extremales. Por lo tanto, el Principio del Máximo de Pontryagin levanta el problema original al espacio cotangente. En esta tesis doctoral, desarrollamos una demostración completa y geométrica del Principio del Máximo de Pontryagin. Investigamos minuciosamente los puntos delicados de la demostración, como son las perturbaciones de los controles, la aproximación lineal del conjunto de puntos alcanzables y la condición de separación. Entre todas las soluciones de un problema de control óptimo, existen las curvas anormales. Estas curvas no dependen de la función de coste que se quiere minimizar, sino que sólo dependen de la geometría del sistema de control. En la literatura de control óptimo existen estudios sobre la anormalidad, aunque sólo para sistemas lineales o afines en los controles y fundamentalmente con funciones de costes cuadráticas en los controles. Nosotros presentamos un método geométrico nuevo para caracterizar todos los distintos tipos de extremales (no sólo las anormales) de problemas de control óptimo genéricos. Este método es resultado de adaptar un algoritmo de ligaduras presimpléctico. Nuestro interés en las extremales anormales es debido a las curvas óptimas estrictamente anormales, las cuales también pueden ser caracterizadas mediante el algoritmo descrito en esta tesis. Como aplicación del método mencionado en el párrafo anterior, caracterizamos las extremales de un problema de control óptimo libre, aquél donde el dominio de definición de las curvas no está dado. En particular, los problemas de tiempo óptimo son problemas de control óptimo libre. Además, somos capaces de dar un ejemplo de una curva extremal estrictamente anormal aplicando el método descrito. Una vez la noción de anormalidad en general ha sido estudiada, nos centramos en el estudio de la anormalidad para sistemas de control mecánicos, ya que no existen resultados sobre la existencia de curvas óptimales estrictamente anormales para problemas de control óptimo asociados a estos sistemas. En esta tesis, se dan resultados sobre las extremales anormales cuando la función de coste es cuadrática en los controles o el funcional a minimizar es el tiempo. Además, la caracterización de las anormales en casos particulares es descrita por medio de elementos geométricos como las formas cuadráticas vector valoradas. Dichos elementos geométricos aparecen como consecuencia del método descrito para caracterizar las extremales. También se considera otro enfoque para el estudio de la anormalidad de sistemas de control mecánicos, que consiste en aprovechar la equivalencia que existe entre sistemas de control noholónomos y sistemas de control cinemáticos. Se prueba la equivalencia entre problemas de control óptimo asociados a ambos sistemas de control, lo que permite establecer relaciones entre las extremales del problema noholónomo y las extremales del problema cinemático. Estas relaciones permiten dar un ejemplo de una curva optimal estrictamente anormal en un problema de tiempo óptimo para sistemas de control mecánicos. Por último, olvidándonos por un momento de la anormalidad, se describe una formulación geométrica de los problemas de control óptimo no autónomos aprovechando la formulación unificada de Skinner-Rusk. Esta formulación es incluso válida para sistemas de control implícitos que aparecen en numerosos problemas de control óptimo de ámbito ingenieril, como por ejemplo, los sistemas Lagrangianos controlados y los sistemas descriptores. / For the last forty years, differential geometry has provided a means of understanding optimal control theory. Usually the best strategy to solve a difficult problem is to transform it into a different problem that can be dealt with more easily. Pontryagin's Maximum Principle provides the optimal control problem with a Hamiltonian structure. The solutions to the Hamiltonian problem, satisfying particular conditions, are candidates to be solutions to the optimal control problem. These candidates are called extremals. Thus, Pontryagin's Maximum Principle lifts the original problem to the cotangent bundle. In this thesis, we develop a complete geometric proof of Pontryagin's Maximum Principle. We investigate carefully the crucial points in the proof such as the perturbations of the controls, the linear approximation of the reachable set and the separation condition. Among all the solutions to an optimal control problem, there exist the abnormal curves. These do not depend on the cost function we want to minimize, but only on the geometry of the control system. Some work has been done in the study of abnormality, although only for control-linear and control-affine systems with mainly control-quadratic cost functions. Here we present a novel geometric method to characterize all the different kinds of extremals (not only the abnormal ones) in general optimal control problems. This method is an adaptation of the presymplectic constraint algorithm. Our interest in the abnormal curves is with the strict abnormal minimizers. These last minimizers can be characterized by the geometric algorithm presented in this thesis. As an application of the above-mentioned method, we characterize the extremals for the free optimal control problems that include, in particular, the time-optimal control problem. Moreover, an example of an strict abnormal extremal for a control-affine system is found using the geometric method. Furthermore, we focus on the description of abnormality for optimal control problems for mechanical control systems, because no results about the existence of strict abnormal minimizers are known for these problems. Results about the abnormal extremals are given when the cost function is control-quadratic or the time must be minimized. In this dissertation, the abnormality is characterized in particular cases through geometric constructions such as vectorvalued quadratic forms that appear as a result of applying the previous geometric procedure. The optimal control problems for mechanical control systems are also tackled taking advantage of the equivalence between nonholonomic control systems and kinematic control systems. In this thesis, it is found an equivalence between time-optimal control problems for both control systems. The results allow us to give an example of a local strict abnormal minimizer in a time-optimal control problem for a mechanical control system. Finally, setting aside the abnormality, the non-autonomous optimal control problem is described geometrically using the Skinner-Rusk unified formalism. This approach is valid for implicit control systems that arise in optimal control problems for the controlled Lagrangian systems and for descriptor systems. Both systems are common in engineering problems.

La tesi si occupa del gruppo cooperativo gerarchico. Nel primo capitolo si esaminano una serie di problematiche legate alle legittimità o meno di una simile struttura di gruppo. Nel secondo capitolo, ricco anche di un'analisi empirica di taluni statuti di gruppi cooperativi gerarchici operanti a livello europeo, si passa all'esame delle modalità di attuazione del rapporto mutualistico in una struttura di gruppo; in particolare, si valuta la possibilità dello spostamento a valle della gestione di servizio con conseguente riduzione della cooperativa capogruppo a holding pura. Nel capitolo terzo si esamina, invece, la compatibilità di una simile struttura di gruppo con i principi fondanti il diritto della cooperazione, ovvero la disciplina dei ristorni, il principio della porta aperta e della parità di trattamento e il criterio della prevalenza dell'attività mutualistica. / My doctorate thesis considers a vertically organized corporation in which the mother company is a cooperative, with particular reference to the repercussions of such a structure on the mutual relationship involved. As the need to compete on the market through a single management body in charge of diversified activities becomes more pressing, the cooperatives currently find themselves at a disadvantage with respect to profit-making enterprises, as their adoption of a holding structure to run their business activities is looked upon with a certain suspicion. There are many who sustain in fact that such a structure is in open conflict with the principles of the cooperative movement, such as, inter alia, the open door principle. In particular, doubts have been raised as to whether the mutual-benefit purpose on which cooperatives are founded, involving the supply of management services to the members at conditions which are more beneficial than those generally available on the market, can be fully applied within a holding structure. In my doctorate thesis, I assert the full legitimacy of the holding cooperative on the basis of a series of arguments which I have developed by comparing several European legal systems, focusing in particular on the key concept of my research, the mutual-benefit purpose in vertical integrated companies.

Many environmental crises are threatening to collapse human societies, but also life on the Earth as we may know. Climate change due to anthropogenic global emissions is one of the main issues, but also soil degradation, and the management of the enormous amount of organic wastes that are harmfully released into the environment by human activities. On the one hand, direct spreading of biowastes onto the land is often limited due to eutrophication or pollution by toxic compounds. On the other hands, these biomasses may contain nutrients, such as phosphorus (listed as a critical raw material) and nitrogen, which could be recovered to sustain the high demand in expensive soil amendments and fertilizers. Thus, finding new solution to close the loop towards circular economy and sustainable processes is crucial, nowadays, to convert the global trends and restore the delicate equilibrium in the water-food-energy nexus, with soil ‘under special surveillance’. In this framework, many researchers are focusing their attention on hydrothermal carbonization (HTC) as a possible candidate, in particular to treat moist biowastes and obtain useful solid (hydrochar) and liquid (HTC liquor) products. Nutrients contained in biowastes are sensitive to HTC process parameters and initial feedstock properties, thus it is crucial to analyze their distribution and (im)mobilization among the HTC products for their reuse in soil. On the other hand, since some organic compounds are generated during the thermochemical process, which may be responsible for toxicity to plants and other organisms, analysis of their possible toxicity towards the biosphere becomes crucial before implementation at a large scale. This thesis collects our efforts to explore new processes and deepen the knowledge about the possibility to produce amendments suitable for soil application from hydrochar. The core is from a process engineering perspective, focusing on the production phase and the characterization of the products, never forgetting any possible limits or the implications on ecotoxicological issues. In the first part of the thesis, ‘How to make hydrochar a soil amendment?’ is the main question. Based on few pioneer studies about composting of hydrochar, we assessed a complete analysis of hydrochar co-compost, produced from the 25-day aerobic stabilization of digestate of organic fraction of municipal solid waste, together with a fraction of its hydrochar, and green waste. Under the umbrella of C2Land project (funded by The European Institute of Innovation & Technology -EIT), we produced this new amendment in specifically designed bioreactors, then we characterized the products from the point of view of physico-chemical properties, nutrients distribution, toxicity to plants and mammalian cells. We are confident that the crucial result of toxicity removal from hydrochar through composting will attract the interest of many stakeholders, since implementing HTC in anaerobic/aerobic plants is almost ready to be applied at a large scale. Moreover, an experimental campaign performed at the University of Leeds further explored the effect of some other post-treatments on hydrochar composition and phytotoxicity, depending on the initial feedstocks (manure, sewage digestate, water hyacinth, and grass). The second part of the thesis was dedicated to nutrients recovery, necessary when some harmful matrixes - such as the municipal sewage sludge digestate - are not allowed to be reused for agricultural purposes, due to law limitations or pollution issues. In this case, nutrients recovery (N, P) could be achieved chemically, via HTC and struvite precipitation, being struvite recognized as a good fertilizer. Firstly, we performed a techno-economic assessment of the implementation at a district level of HTC-centered sewage sludge management. The mass reduction of waste streams may have some important effects on transportation costs, while the recirculation of HTC liquor back to the anaerobic digestors can imply more biomethane production with increased revenues. A mass balance for the potential of N and P recovery through struvite precipitation in the centralized facility was also assessed. Secondly, a near-zero waste treatment process for municipal sewage sludge via HTC was designed according to the available literature and preliminarily analyzed at lab level. The fractionation of the different types of phosphorus was analyzed through the STM-P protocol before and after HTC, confirming the mineralization of organic phosphorus during the process. Citric acid was validated as a good green solvent for phosphorus extraction and high-quality struvite precipitation, even if the process was not still optimized in terms of yields. Future works may identify the best process parameters for final metal recovery from liquid byproducts in order to internally recirculate them back to water line, and to characterize the leached hydrochar as purified renewable fuel or soil amendment. Thus, the proof-of-concept chain would be confirmed and could be applied to the sustainable HTC-centered biorefineries of the future.

In a worldwide context where the community has to make giant leaps forward to contain the catastrophic consequences of climate change, we need to face the discordant “How do we power our economies?” with green and circular solutions instead of hiding behind the hypocrisy of fossil fuels. Biomass, renewable, abundant, and cheap, can trigger a shift towards a zero-carbon emission economy, in which it substitutes fossil fuels for the production of energy and materials. Among the strategies to valorize biomass, hydrothermal processes are green pathways for producing biofuels and bio-based materials. However, research has yet to fill several gaps to make these processes ready for industrial scaling and spreading. Therefore, along with this Ph.D. thesis, we provide new insights into hydrothermal processes, touching several scientific areas: from in-depth research around the thermochemical fundamentals to the engineering of new sustainable and biorefinery concepts. Through fundamental research, we try to answer “What’s happening during hydrothermal processes?” facing the enormous complexity of the process by investigating chemical pathways, kinetics, and thermodynamics. Facing sustainability, we explored the coupling of hydrothermal conversion with concentrated solar energy to develop a zero-energy process and the integration of hydrothermal carbonization with subsequent treatments to valorize by-products.

This study aim at the valorization of wine industry by products; particularly on the extraction and characterization of grape seeds oil using supercritical CO2 (SC-CO2) and polyphenols from grape skins and defatted grape seeds using subcritical water (SW) and then, modeling of the kinetics of extractions and process economic analysis. The overall objective of the work is to develop recovery strategies for wine-making wastes in order to reduce their environmental impact and to valorize them in order to provide wine-makers with the possibility of selling by-products at a profitable price. To address the objectives, the work is divided into seven Chapters. In Chapter 1, some general overview and the fundamental of SC-CO2 and SW technologies along with emerging areas of applications are presented. Special emphasis is given to the work in the field of valorization of agro-industrial by-products. Then, the Chapter ends by stating the general and specific objectives of the thesis. The second Chapter is devoted to the characterization of grape seeds oil. To make the result more holistic, grape seeds from six grape cultivars were extracted using SC-CO2 in two subsequent harvesting years and the resulting oils were characterized. Comparative extractions were also performed by utilizing conventional solvent extraction using n-hexane and by mechanical press. The results testify the potentiality of grape seed oil as a source of unsaturated fatty acids and tocols. Moreover, they offers a clear picture of the similarities and differences among oils from different grape cultivars and obtained through different extraction techniques. The third Chapter is dedicated to compare the effectiveness of the models used to evaluate the kinetic of SC-CO2 extraction curves. Particularly, three models, the broken and intact cells (BIC), the shrinking core (SC), and the bridge (combined BIC-SC) models are critically analyzed. The objective of the Chapter is to objectively choose the best model that can be used in the subsequent Chapters. In order to model the kinetics of SC-CO2 extraction, one of the very important parameter is the solute solubility. But solubility data (especially of grape seed oil) is very scares in the literature. The bulk majority of the scientific works estimate the value of solubility of solute in SC-CO2 from theoretical models. So, the fourth Chapter is devoted to experimental determination of solubility of grape seed oil in SC-CO2 over a range of pressure and temperature of practical importance and the data were modeled by different models to compare their effectiveness. The fifth Chapter is aimed to study the effect of the main process variables affecting the SC-CO2 extraction of oil from grape seeds, both experimentally and through modeling. The dependency of the extraction kinetics on the variables more tested in the literature (pressure, temperature, particle size and solvent flow rate) was confirmed, and original trends were obtained for the less investigated variables, such as the bed porosity (ε), the extractor diameter to length ratio (D/L), the extractor free volume and the type of cultivars. In the sixth Chapter the attention is moved to the valorization of grape skins and defatted grape seeds by using SW. The results show that, both skins and defatted seeds contain significant concentration of polyphenols and SW is a potential green solvent for extracting valuable polyphenols from wine-making by-products. The extraction kinetics was also simulated by a simple model available in the literature. In the seventh and last Chapter, a preliminary economic feasibility study was investigated for the establishment of SC-CO2 extraction plant for the extraction of grape seeds oil. The result shows that, a SC-CO2 extraction plant is technically viable and economically feasible for the extraction of grape seed oil with estimated rate of return on investment at 8.5% and payback period of 5 year at current minimum retail selling price of grape seed oil in the market. The project has an attractive socio-economic and environmental benefit and generates substantial revenue for the local government in the form of tax and will allow wine-makers to sell wet grape marc at a price of up to US$ 10/ton.