The potential of the production of fuels and chemicals from marine biomass

The need for sustainability, energy security and reduction of global warming has brought many alternative energy sources into the foreground. Already there are well established technologies that can produce renewable energy but when it comes to the production of renewable liquid fuels and chemicals, biomass is the primary feedstock. Biomass is a renewable source of energy that can provide heat, electricity and transport fuels. However, utilisation of biomass posses some limitations such as land availability and competition of energy crops with food crops. In order to overcome these problems "third generation" biofuels from alternative feedstock such as macro-algae have recently come into the foreground. Oceans and seas cover over 70% of the earth's surface, most of which is under exploited, resulting in additional potential for biomass production. This thesis concentrates on the potential for production of bio-energy and chemicals from macro-algae through thermochemical processes such as pyrolysis, combustion and hydrothermal liquefaction. Utilisation of aquatic biomass for production of bioenergy is a very recent concept and there is a lack of information on their thermochemical behaviour. This investigation contributes to a wider study and forms part of the Supergen II bionergy programme investigating the potential for utilisation of macrolage in the UK. This investigation includes a detailed characterisation of the fuel properties and thermal behaviour of a range of wild seaweeds around the UK provided by the Scottish Association of Marine Sciences. In addition, a range of model biochemical components have been investigated, in particular, the model carbohydrates present in macro-algae. Alginic acid, mannitol, laminarin, fucoidan and cellulose are the main carbohydrates present in brown macro-algae. The rest of the plant material comprises of protein and ash. Freshly harvested macro-algae contain 80-90wt% moisture. Their ash content is high, reflecting their high inorganic content. Potassium is the most abundant metal present in macro-algae although other metals are also present including sodium, calcium, magnesium, Their carbohydrate, protein and ash content undergo a seasonal variation during their growth cycle. This variation was found to affect their properties as fuel. Carbon content reaches its maximum during summer - early autumn. During the same period, the inorganic (and thus ash) content is at its minimum suggesting summer - early autumn as the optimum period for harvesting macro-algae for bioenergy. The high carbon and low inorganic content during this period is reflected in its higher heating value but it is still relatively low (13-14 MJ/kg) when compared with terrestrial biomass. The nature of the inhabitant location was found to significantly influence macro-algae fuel properties with samples grown in the open ocean having better fuel properties (higher HHV and lower inorganic content) than samples growing in canals and estuaries. Investigation of the pyrolysis behaviour was performed using thermal analysis such as TGA and Py-GC/MS. The volatile matter evolved during pyrolysis was higher for samples collected during summer and early spring due to their higher carbon content. The main volatiles evolved during decomposition were found to originate either from their carbohydrates or from their protein content. Specific marker compounds were identified for the carbohydrates such as dianhydromannitol, 1-(2-furanyl)-ethanone, 2-hydroxy-3-methyl-2-cyclopenten-1-one and furfural for manitol, laminarin and alginic acid respectively. Proteins are found to produce a range of indoles and pyrroles. Some of the compounds identified may have industrial applications indicating the possibility of producing chemicals through pyrolysis of macro-algae. The high moisture content of seaweed necessitates that significant amounts of water must be removed before this feedstock can be converted by pyrolysis. The high moisture content is similary an issue for combustion which has been assessed by a combination of TGA and characterisation of the biomass. Macro-algae have a low HHV, high halogen content and high ash content and are predicted to have high slagging and fouling behaviour in conventional combustion chambers. This fouling behaviour is predicted through empirical indexes such as the alkali index and is shown to be higher than terrestrial biomass even during summer - early autumn when their inorganic content is at minimum. Typical ash contents vary from 18 to 45wt% and contain mainly oxides of K20, Na2O, CaO and MgO. Pre-treatment prior to combustion can significantly reduce the ash content leading to improved combustion properties, but this also leads to removal of some biochemical components. Using an acid pre-treatment, some of the seaweed's biopolymers, such as mannitol or fucoidan, can be removed presenting the possibility for acquiring valuable chemicals from seaweed before combustion of the residue. An alternative processing route, capable of processing wet feedstocks called hydrothermal liquefaction (HTL) involves the processing of the macro-algae in subcritical water. HTL converts the starting material into four product streams including a bio-crude, a char, an aqueous stream consisting primarily of process water and a gaseous stream. A parametric study of HTL has been investigated using high pressure batch reactors with or without the presence of catalysts. The bio-crude produced from the liquefaction of macrolgae was found to have a high heating value and resembling chemical composition to crude-oil. It can be used directly as a fuel however it still contains significantly high nitrogen levels and will required suitable upgrading (e. g. denitrogenation). The bio-char was found to also have a high heating value. Both bio-crude and bio-char produced from HTL are virtually free of alkali metals suggesting they are suitable for combustion. Reaction conditions such as temperature and the ratio of biomass to water have the greatest influence on product yields and properties. Typical bio-crude yields were in the range of 10 to 19wt% on a daf basis with their HHVs ranging from 32 to 38 MJ/kg. The yields of bio-chars were in similar range (IOwt% to 19wt% on a db) with HHVs between 10 and 26 MJ/kg. An energy balance was calculated in order to investigate the energy required to heat the mixture of macro-algae and water. The energy recovery in the bio-crude and bio-char was relatively low, between 50 and 65%, indicating that a significant portion of the energy content of macro-algae is passing in to the other product streams. The aqueous phase (process water) was found to be rich in metals, especially alkali metals, and sugars, and its composition suggests it maybe possible to utilize it as a fertilizer. A fraction of the sugars present in macro algae (mannitol and laminarin) pass in to the aqueous stream, suggesting there is also potential for fermentetion to bioethanol. The gaseous stream is composed mainly of CO2, N, CO and lower concentrationso H and CH4. The most suitable thermochemical processing route for macro-algae is proposed to be hydrothermal liquefaction and has potential for utilization of all the product streams producing fuels and chemicals using a bio-refinery concept

Hydrothermal liquefaction of food waste: optimization and kinetic modelling

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Wet Oxidation as an enabling technology for hydrthermal liquefaction

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Hydrothermal liquefaction of organic waste streams on a continuous pilot scale reactor

Hydrothermal liquefaction (HTL) is a promising technology for biofuel production and treatment of organic wastes and biomass. Due to the wet nature of the process where biomass is heated in an aqueous slurry at 350°C and 200 bar, wet biomass and wet wastes are particularly suited for the process. The current study investigates the utilization of wastewater treatment sludges and other organic wastes for the production of sustainable petroleum replacement products. The work has been carried out on a pilot scale continuous hydrothermal liquefaction reactor with a novel oscillating flow system and heat exchanger. The influence of these are discussed in terms of heat recovery and operability of the plant. The reactor was run at 50 L/h with maximum solids loadings of ~25% and short residence times of80% was accomplished, leading to an energy efficient process. During operation of the HTL system, approximately 5 units of energy are created in the form of bio-crude for every unit of energy invested for heating and pumping the slurry (EROI\u3e5). We present and discuss the results of processing diverse samples ranging from high ash (sewage sludge), lignocellulosics (miscanthus) and manure to microalgae. The potential of mixing different waste biomasses such as sludge and lignocellulosics, plastics and lignocellulosics is explored during this research and synergistic effects on bio-crude yields and fuel quality are observed, leading to higher carbon and energy recoveries. Water phase recycling of the HTL process water was employed during the liquefaction of pine where a significant increase in bio-crude yields, energy recovery and energy return on investment could be achieved. Initial results on bio-crude upgrading via catalytic hydrotreatment are also presented, demonstrating the feasibility of the HTL process as a viable pathway towards drop in replacement fuels. The current presentation gives a realistic insight into the processing of diverse biomass feedstocks at pilot scale, showing the potential of the technology while areas for future development and bottlenecks are highlighted

A Case of Asymptomatic Brugada Electrocardiographic Pattern Incidentally Unmasked During the Recovery Phase of an Exercise Stress Test

The interest about Brugada syndrome, an inherited channelopathy associated with sudden cardiac death in individuals without structural heart disease, is exponentially increasing lately. Similarly to chameleon, the electrocardiographic (ECG) signal of the disease fluctuates over time, it is often concealed, and may be unmasked under certain conditions. Recently, emergence of the characteristic ST-segment elevation during exercise stress test (EST) has been reported, probably resulting from an alteration of the autonomic tone in the different stages of exercise. We present the case of a 43-year-old, otherwise healthy male with an asymptomatic Brugada ECG pattern incidentally unmasked during the recovery phase of an EST

Importance of genotype for risk stratification in arrhythmogenic right ventricular cardiomyopathy using the 2019 ARVC risk calculator

none41siTo study the impact of genotype on the performance of the 2019 risk model for arrhythmogenic right ventricular cardiomyopathy (ARVC).Protonotarios, Alexandros; Bariani, Riccardo; Cappelletto, Chiara; Pavlou, Menelaos; García-García, Alba; Cipriani, Alberto; Protonotarios, Ioannis; Rivas, Adrian; Wittenberg, Regitze; Graziosi, Maddalena; Xylouri, Zafeirenia; Larrañaga-Moreira, José M; de Luca, Antonio; Celeghin, Rudy; Pilichou, Kalliopi; Bakalakos, Athanasios; Lopes, Luis Rocha; Savvatis, Konstantinos; Stolfo, Davide; Dal Ferro, Matteo; Merlo, Marco; Basso, Cristina; Freire, Javier Limeres; Rodriguez-Palomares, Jose F; Kubo, Toru; Ripoll-Vera, Tomas; Barriales-Villa, Roberto; Antoniades, Loizos; Mogensen, Jens; Garcia-Pavia, Pablo; Wahbi, Karim; Biagini, Elena; Anastasakis, Aris; Tsatsopoulou, Adalena; Zorio, Esther; Gimeno, Juan R; Garcia-Pinilla, Jose Manuel; Syrris, Petros; Sinagra, Gianfranco; Bauce, Barbara; Elliott, Perry MProtonotarios, Alexandros; Bariani, Riccardo; Cappelletto, Chiara; Pavlou, Menelaos; García-García, Alba; Cipriani, Alberto; Protonotarios, Ioannis; Rivas, Adrian; Wittenberg, Regitze; Graziosi, Maddalena; Xylouri, Zafeirenia; Larrañaga-Moreira, José M; de Luca, Antonio; Celeghin, Rudy; Pilichou, Kalliopi; Bakalakos, Athanasios; Lopes, Luis Rocha; Savvatis, Konstantinos; Stolfo, Davide; Dal Ferro, Matteo; Merlo, Marco; Basso, Cristina; Freire, Javier Limeres; Rodriguez-Palomares, Jose F; Kubo, Toru; Ripoll-Vera, Tomas; Barriales-Villa, Roberto; Antoniades, Loizos; Mogensen, Jens; Garcia-Pavia, Pablo; Wahbi, Karim; Biagini, Elena; Anastasakis, Aris; Tsatsopoulou, Adalena; Zorio, Esther; Gimeno, Juan R; Garcia-Pinilla, Jose Manuel; Syrris, Petros; Sinagra, Gianfranco; Bauce, Barbara; Elliott, Perry

Current perspectives on the diagnosis and management of dilated cardiomyopathy Beyond heart failure: a Cardiomyopathy Clinic Doctor's point of view

Left ventricular enlargement and dysfunction are fundamental components of dilated cardiomyopathy (DCM). DCM is a major cause of heart failure and cardiac transplantation. A wide variety of etiologies underlie acquired and familial DCM. Familial disease is reported in 20% to 35% of cases. A genetic substrate is recognized in at least 30% of familial cases. A recently proposed scheme defines DCM as a continuum of subclinical and clinical phenotypes. The evolution of classification systems permitted use of effective treatment strategies in disorders sharing the same structural and functional characteristics and common clinical expression. The major causes of death are progressive heart failure and sudden cardiac death secondary to ventricular arrhythmias or less commonly bradyarrhythmias. Remarkable progress has been made in survival owing to well-defined evidence-based therapies and appropriate guidelines for risk stratification and sudden cardiac death prevention measures. Neurohormonal antagonists and device therapy decreased all-cause mortality in adult patients with DCM. However, additional red flags in diagnosis have to be addressed in everyday practice, and cardiologists have to be aware of the subsequent effect on risk stratification and treatment plan. Genetic substrate cannot be modified, but the presence of a peculiar type of gene mutation modifies thresholds for implantable cardioverter defibrillator (ICD) implantation. DCM is part of the spectrum of heart failure which is a syndrome with certain morphological and functional characteristics. Although significant progress has been achieved in the management of patients with DCM, it seems that the future treatments of this entity will be related to the specific pathological substrate. Keywords: Dilated, Cardiomyopathy, Familial, Genetics, Myocarditi

Continuous Hydrothermal Liquefaction of Biomass in a Novel Pilot Plant with Heat Recovery and Hydraulic Oscillation

Hydrothermal liquefaction (HTL) is regarded as a promising technology for the production of biofuels from biomass and wastes. As such, there is a drive towards continuous-flow processing systems to aid process scale-up and eventually commercialization. The current study presents results from a novel pilot-scale HTL reactor with a feed capacity of up to 100 L/h and a process volume of approximately 20 L. The pilot plant employs a heat exchanger for heat recovery and a novel hydraulic oscillation system to increase the turbulence in the tubular reactor. The energy grass Miscanthus and the microalgae Spirulina, both representing advanced dedicated energy crops, as well as sewage sludge as high-potential waste stream were selected to assess the reactor performance. Biomass slurries with up to 16 wt% dry matter content were successfully processed. The heat recovery of the heat exchanger is found to increase with reactor run time, reaching 80% within 5–6 h of operation. The hydraulic oscillation system is shown to improve mixing and enhance heat transfer. Bio-crudes with average yields of 26 wt%, 33 wt% and 25 wt% were produced from Miscanthus, Spirulina and sewage sludge, respectively. The yields also appeared to increase with reactor run time. Bio-crude from HTL of Spirulina was mainly composed of palmitic acid, glycerol, heptadecane and linolelaidic acid, while biocrude from sewage sludge contained mainly palmitic acid, oleic acid and stearic acid. In contrast, biocrude from HTL of Miscanthus consisted of a large number of different phenolics. An energetic comparison between the three feedstocks revealed a thermal efficiency of 47%, 47% and 33% and energy return on investment (EROI) of 2.8, 3.3 and 0.5 for HTL of Miscanthus, Spirulina and sewage sludge, respectively