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• Study evaluates generation from biomass gasification. • Syngas is used within poly-generation systems to generate sustainable fuels. • The article considers recycling of multiple sources of biomass to generate syngas. • A new poly-generation process to produce urea, liquids fuels and power is proposed. • A novel hybrid environmental and economic optimisation methodology is proposed. The production of renewable chemicals and fuels is driving modern society towards a type of sustainable development which involves a decreasing dependency on fossil fuels and the minimisation of waste. Biomass, a waste by-product from the urban environment, is a carbon dioxide neutral organic fuel that can potentially serve as a feedstock for the production of sustainable power and heat. Gasification is preferred over the other thermal conversion options for biomass processing whereby the product synthesis gas can be utilised to power generators/turbines and generate clean energy, ammonia and methanol. Incidentally, efficient and economically sound biomass driven supply chains can be integrated into an existing petrochemical infrastructure. Moreover, the potential production volumes of fuels and green chemicals can also be increased by the addition of multiple biomass sources, thereby creating potential positive scale effects. This study proposes a new poly-generation process that utilises multiple sources of biomass feedstock to produce high quality urea, methanol, Fisher-Tropsch liquids and power. Four flowsheet configurations are simulated using Aspen Plus software and the built-in capabilities of the activated analysis using Aspen Process Economic Analyzer and Aspen Energy Analyzer to perform the economic, energy and environmental impact calculations. The results demonstrate that the methanol production technique is the most economic process pathway with a net profit of approximately $0.035 per kg of biomass input, whilst the urea process pathway presents the lowest environmental impact solution with approximately 0.71 kg of CO 2 -e per kg of biomass input. These results are relative and can be analysed from different perspectives based on the market demand of the products and their applications and local need. For instance, considering at the economic and environmental indicators relative to the production capacity, production of liquid fuels achieve net profits of approximately $0.27 per kg of product, whilst urea production demonstrates the lowest environmental emissions of approximately 3.93 kg of CO 2 -e per kg of product. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hybrid biorefinery is developed for jet biofuel production. • The system provides a unique integration of technologies, streams, and heat. • The system accommodates multiple biomass from different solid and liquid categories. • A 22% reduction in jet fuel price is achieved as compared to the conventional Jet-A. • A 41% mitigation of associated emissions is attained relative to Jet-A. Jet biofuel (JBF) is identified as an essential solution to mitigate the carbon footprint of the aviation sector. Since aeroplanes rely solely on liquid fuels, the development of pathways that generates JBF as a major product has become crucial. Thus far, seven pathways to produce JBF have been developed and certified over the past decade. Each of these pathways accommodates a specific type of biomass. However, the availability, sustainability and feasibility of feedstocks to fulfil the growing demand on jet fuel remains an issue. As such, this study presents a holistic approach for the design of a state-of-the-art hybrid biorefinery that accommodates multiple biomass feedstocks across different categories including energy crops (i.e., Jatropha energy crop), dry biomass (i.e., municipal solid waste) and wet biomass (i.e., livestock manure). A Qatar-based industrial scale biorefinery was modelled in Aspen Plus® considering a pre-defined geospatial distribution of biomass and the optimal biorefinery site in the country. The hybrid system integrated advanced technologies such as hydroprocessing, Fischer-Tropsch, gasification, dry-reforming and hydrothermal liquefaction. While biomass optimal insertion streams were evaluated using a prediction model. Besides, intensive materials, heat, water and power integrations were performed to maximise JBF production, mitigate its environmental impact and control its cost. The system generated 328, 94 and 44 million litres of JBF, gasoline and diesel, respectively. Produced JBF was characterised and found to comply with all international standards. The generated JBF can substitute 15.3 % of Qatar's jet fuel needs, while it can power around one third of its fleet considering a maximum allowable jet biofuel blend of 50 %. The proposed model achieved a minimum selling price of JBF at 0.43 $/kg, which is 22 % lower than the market price of conventional Jet-A fuel (2019). In addition, the environmental analysis of the model indicated a 41 % mitigation in greenhouse gas emissions achieved by JBF throughout its lifecycle, relative to Jet-A fuel. [ABSTRACT FROM AUTHOR]

• Whole-fruit of Jatropha curcas is processed into jet fuel in novel integrated system. • The System implements 5 integration techniques to enhance jet fuel yield and cost. • 49 wt% of Jatropha fruit is converted into liquid fuels, with 65% jet fuel selectivity. • An increment of 88% of jet fuel yield is obtained by utilising the whole-fruit. • A minimum selling price of 0.445 $/kg of jet fuel is achieved below market price. The production of 'Jet Biofuel' has been identified as a promising strategy to mitigate the carbon footprint of the aviation sector. During the past decade, the commercial production of Jet Biofuel has attracted the attention of airline companies and governments across the globe. However, achieving a competitive production cost and sustainable Jet Biofuel remains a challenge. In this regard, various feedstocks have been tested for this purpose, where the vast majority have not complied with sustainability and feasibility expectations. Although not fully utilised in the Jet Biofuel industry, Jatropha curcas has emerged as one of the most promising feedstocks for Jet Biofuel production, since it is non-edible and is able to grow in non-arable lands with minimal water and energy requirements. This study presents a novel integrated pathway that utilises all parts of Jatropha fruit to produce a cost-effective Jet Biofuel using conventional hydroprocess, gasification, Fischer-Tropsch and reforming technologies. Different integration techniques are employed, including waste valorisation, by-products incorporation, as well as water, heat and power integration. The effect of various operating parameters on the products' characteristics and yields has been evaluated. The model is validated against literature experimental data and demonstrates promising results. Whereby, 49 wt% of Jatropha fruit is converted into liquid fuels, with a Jet Biofuel selectivity of 65%, which represents an increment of almost 88% of Jet Biofuel yield compared to processing Jatropha oil alone. Furthermore, the system developed is power and water self-sufficient. The proposed pathway significantly lowers the production cost of Jet Biofuel below the market price of conventional Jet-A fuel for the base year of analysis, achieving a minimum selling price of 0.445 $/kg. [ABSTRACT FROM AUTHOR]

• The study evaluates generation of sustainable products from biomass gasification. • Two types of gasifying medium; oxygen and steam, are compared. • The article considers recycling of a blended feed of multiple biomass sources. • Aspen plus is utilised to simulate and integrate the different processes. • Poly-generation of Fisher-Tropsch liquids, methanol, urea and power is considered. Economically, fossil fuels remain the main source of energy despite their high emissions of greenhouse gases. However, biomass, a renewable fuel with CO 2 neutrality, has experienced widespread attention as a potential contributor to sustainable development of the energy sector. Gasification is an important thermochemical process that converts biomass feedstock into H 2 -rich combustible gases, which are favoured by wide downstream applications. The use of pure steam or oxygen as a gasifying agent is preferred to increase the yield of combustible gases. Consequently, hydrogen is utilised as an important intermediary in the generation of value-added products such as urea, fuels and power. This study compares the biomass gasification using oxygen-only and steam-only gasifying agents. Moreover, the study examines a poly-generation system that consumes biomass feedstock of multiple sources to produce high grade Fisher-Tropsch liquids, methanol, urea, and power. To achieve this aim, four Aspen Plus simulation flowsheets are developed considering both gasifiying agents and compared utilising the built-in economic and environmental capabilities. The results obtained from the economic and environmental evaluation demonstrate the excellence of steam-only biomass gasification in providing profitable and cleaner products. The methanol production using steam gasification is the most economical solution with a net profit per input of $0.12 per kg of biomass input and the lowest emissions pathway with 0.68 kg of CO 2 -e per biomass input. The relative nature of the results can offer diverse perspectives depending on the market situation of the products. Consequently, analysing the results relative to production capacity, power generation using steam gasification achieves a net profit approximated at $0.80 per kg of product, whilst methanol production using steam gasification remains the lowest environmental impact solution with 2.32 kg of CO 2 -e per output product. [ABSTRACT FROM AUTHOR]

• Thermal conductivity & specific heat capacity of carbon nanofluids enhanced with particle loading. • The energy cost reduced by 10.37%, using nanofluids based heat transfer in solar thermal systems. • Thermal energy storage volume reduced by 21%, using carbon nanotubes based heat transfer fluids. • The effect of pressure on heat capacity and thermal conductivity remains marginally low till 100 bar. • Water nanofluid thermal conductivity increased till 130 °C and then it starts reducing with temperature. Nanofluids are of paramount importance for the development of efficient and competitive heat transfer fluids. The research paper presents a comprehensive study of the thermal properties for developing water and Therminol oil-based nanofluids to operate at high pressure and temperature, which will ultimately support the development of a more comprehensive understanding for nanofluids based heat transport phenomena. Multiwall carbon nanotubes were suspended in water and Therminol 66 at three different weight concentrations from 0.05% to 0.5% with Acacia Gum and oleic acid as surfactants for water and Therminol 66, respectively. The experimental results show more than a 35% enhancement in the thermal conductivity for both the water-based nanofluids and Therminol-66 based nanofluids. This thermal conductivity was also found to be similar with small increment at high pressures for both the base fluid and nanofluids, up to 70 bar pressure and 300 °C. Furthermore, the simulations carried out on parabolic trough collector solar thermal system using nanofluid properties and system advisor model software, showed an enhancement in energy production along with 10.37% reduction in real power purchase agreement price as well as 21% reduction on the thermal energy storage volume. [ABSTRACT FROM AUTHOR]