Thermogravimetric and Kinetic Analysis of Waste Biomass and Plastic Mixtures

Thermogravimetric and kinetic analysis of biomass and plastic co-pyrolysis can provide valuable inputs for a better understanding of decomposition mechanisms. Such inputs are important for selecting the appropriate process conditions but can also be helpful for process modelling. This work investigates the properties of heterogenous sawdust in a mixture with polypropylene and polystyrene. Thermogravimetric analysis is conducted to determine the decomposition mechanism and kinetic parameters of investigated mixtures and to derive appropriate conclusions regarding their further utilization potential. Co-pyrolysis was performed on mixtures with the following biomass/plastic ratios: 75-25%, 50-50%, 25-75%, over a temperature range of 30-550 °C, at four heating rates 5, 10, 20, and 30 °C/min, with pure argon as a carrier gas. Obtained results were then subjected to comprehensive kinetic and thermodynamic analysis. The primary goal was to determine effective activation energies using model-free methods, pre-exponential factors, and elementary thermodynamic parameters such as changes in enthalpy, entropy, and free Gibbs energy. Finally, the influence of the heating rate and mixture composition was extensively investigated by analyzing calculated parameters. &nbs

Environmental management as a pillar for sustainable development

There is a growing concern about how to minimize the impact of human activities on the environment. Already nowadays, in some places adaptation efforts are needed in order to avoid the irreversibility of negative human activities. Due to climate changes, and corresponding environmental and social changes, there is a great need for a more sustainable development of mankind. Over the years, research studies that analyzed the sustainable development of different communities with a multi-disciplinary approach, stressed the necessity of preserving the environment for next generations. Therefore, responsible and conscientious management of the environment is a pillar of the sustainable development concept. This review introduction article provides an overview of the recent top scientific publications related to sustainable development that mostly originated from previous SDEWES conferences.status: publishe

Troubleshooting the problems arising from sustainable development

Sustainable development as a concept of societal development encompasses some problems that need to be addressed carefully. They relate to overcoming the technical limits of individual systems, reducing environmental impact, social inclusion, green economic progress involving all stakeholders, limiting the impact of human activities, etc. Over the past few years, as a result of the increasingly pronounced climate change, more and more studies are addressing these problems and stress the importance of sustainable development. The key to sustainable development are, therefore, the solutions to the problems currently encountered by various stakeholders, that together contribute to the preservation of the environment for future generations. This is no longer based on the goodwill of individuals, but has become the responsibility of the entire generation. This article presents some examples of the solutions for the problems arising from sustainable development and is an overview of recent scientific achievements in the field of sustainable development that emerged from recent Sustainable Development of Energy, Water and Environment Systems (SDEWES) conferences. As such, it acts as an editorial paper for the virtual special issue of the Journal of Environmental Management, that is dedicated to the SDEWES2017 conference.status: publishe

Thermogravimetric Analysis Investigation of Polyurethane Plastic Thermal Properties Under Different Atmospheric Conditions

Recycling and energy recovery of waste plastic are major categories of modern solid waste management systems. Since the lower heating values of plastics are around 30 MJ/kg, equivalent to traditional solid fuels, such as petroleum coke, coal and charcoal, waste plastics are considered as potential fossil fuels alternatives in various industrial sectors. Already nowadays, energy recovery of waste plastic is typically conducted by combustion in incinerators or cement kilns. However, due to various types of waste plastics, their thermochemical behaviour has been rarely investigated. Even more, the thermochemical behaviour of waste plastics under oxy-combustion conditions has even rarely been studied. In this study non-isothermal thermogravimetric analyser was used to study the thermochemical behaviour of polyurethane plastic waste under seven different atmospheric conditions. Polyurethane decomposition kinetic constants have been estimated by the simultaneous evaluations of seven weight loss curves measured for the heating rate of 20 K/min and a final temperature of 1,073 K. The obtained results showed that the combustion of polyurethane is mainly composed of two stages, and the higher oxygen concentration slightly influenced the first stage but highly accelerates the second one, ascribing to a higher mean weight loss rate and an increasing activation energy. Replacing carbon dioxide with nitrogen slightly influences the first stage while positively influences the second stage, expressing in lower peak temperatures in differential thermogravimetry curves and higher peak values in differential scanning calorimetry curves

Sustainable development using renewable energy technology

This article present a review of the status of research within the exploitation of renewable energy sources with a focus on the status of technologies exploiting renewable energy sources, a status of the assessment of the availability of renewable energy sources and the status on the research into the types of systems, that can integrate renewable energy sources. In terms of technologies and resources, wind and wave power resources, wind technology, geothermal energy, solar heating, cooling and electricity and salinity gradient technologies are reviewed. Lastly, system integration, impacts and environmental performance of energy systems are assessed. The review takes a starting point in work presented at the conference series on Sustainable Development of Energy, Water and Environmental Systems (SDEWES), published in Special Issues in various journals and puts this work into a wider context

Effects of Particle Size and Mainstream Inlet Angle on Deposition in a Turbine Cascade

Based on the critical velocity model, impact and capture efficiencies in an AGTB turbine cascade are investigated numerically under various inlet angles of mainstream, blowing ratios, particle sizes, and particle densities. The effect of hole configuration on deposition is analyzed based on comparisons of results from combined hole and cylindrical hole. The impact efficiency increases with the increase of particle size. Impact area on pressure side of blade surface expands with increasing of the mainstream inlet angle from 123 deg to 143 deg. The capture efficiency decreases with the increase of blowing ratio for 10 µm particles. For particles with densities of 1485 kg/m3, 1980 kg/m3, and 2475 kg/m3, the maximum capture efficiency is reached when the particle size is 5 µm. The particle capture efficiency for the combined hole is up to 3.9% lower than that for cylindrical hole when the mainstream inlet angle is 123 deg

A 4E feasibility analysis of an on-site, ammonia sourced, hydrogen refueling station

Since hydrogen (H2) demand in the transportation field has increased as a result of efforts to reduce carbon emissions, the number of H2 refueling stations has been increasing as well. However, the transportation of H2 itself requires a lot of energy due to the low volumetric density of H2 necessitating energy-intensive processes of compression or liquefaction. In this context, ammonia (NH3) has been emerging as an efficient H2 carrier with several beneficial characteristics such as a large weight fraction of H2 (17.65%), and liquefaction at ambient temperature and moderate pressures which allows for the utilization of existing fossil fuel infrastructure. Thus, NH3 can be utilized as an H2 transport medium as well as a raw material for remote H2 refueling stations. In this study, a comparative 4E (energy, exergy, economic, and environmental) analysis of an H2 refueling station supplied from an on-site NH3 reforming using a packed bed reactor (PBR) and a membrane reactor (MR) is performed. Due to the higher H2 recovery in the MR, a greater H2 production rate is observed resulting in lower H2 production cost. Compared to the PBR, energy and exergy efficiency in the MR-based process are improved by 3.6%p and 2.7%p reaching 82.7% and 78.7%, respectively, and greenhouse gas emissions are reduced by -17% from 5.4 to 4.5 kgCO2-eq kgH2- 1. The break-even price of H2 in the MR-based process at present is 8.1-9.2 USD kgH2- 1 (at scale of 900 kgH2 d-1) and the break-even points with the H2 selling price of 12.5 USD kg H2- 1 are 7.8-8.9 y whereas the corresponding values are 9.4-10.5 USD kgH2- 1 and 10.2-12.3 y in the process using the PBR. At an H2 selling price of 7.5 USD kgH2- 1, most cases (90.6%) of the net present value in the MR-based process were positive in 2040 indicating an economically feasible process, while cases with lower H2 selling price (2.5 and 5.0 USD kgH2- 1) were not deemed profitable under current technological level

Flexible Carbon Capture and Utilization technologies in future energy systems and the utilization pathways of captured CO2

Future 100% renewable energy systems will have to integrate different sectors, including provision of power, heating, cooling and transport. Such energy systems will be needed to mitigate the negative impacts of economic development based on the use of fossil fuels, but will rely on variable renewable energy resources. As two-thirds of global greenhouse gas emissions can be attributed to fossil fuel combustion, decarbonization of energy systems is imperative for combating the climate change. Integrating future energy systems with CO2 capture and utilization technologies can contribute to deep decarbonization. As these technologies can be operated flexibly, they can be used to balance the grid to allow for high levels of variable renewable energy in the power mix. The captured CO2 can be either utilized as a feedstock for various value-added applications in the chemical industry and related sectors such as the food and beverage industries. This paper reviews the state-of-the-art literature on CO2 capture and utilization technologies, with an emphasis on their potential integration into a low-carbon, high-renewables penetration grid. The potential market size for CO2 as raw material is also elaborated and discussed. The review paper provides an insight to the development and the technological needs of different energy system sectors, as well the limitations, challenges and research gaps to the integration of the variable renewable energy sources and flexible carbon capture and utilization technologies

An efficient process for sustainable and scalable hydrogen production from green ammonia

This study comprehensively investigates hydrogen production from green ammonia reforming, including synthesis of catalysts, reactor development, process integration, and techno-economic analysis. In-house developed Ru/La-Al2O3 pellet catalyst having perovskite structure showed high catalytic activity of 2827 h(-1) at 450 degrees C and stability over 6700 h at 550 degrees C, exceeding the performance of the majority of powder catalysts reported in the literature. A scalable 12-faceted reactor adopting the as-produced catalyst was designed to enhance heat transfer, producing over 66 L min(-1) of hydrogen with state-of-the-art ammonia reforming efficiency of 83.6 %. Near-zero CO2 emission of hydrogen extraction from green ammonia was demonstrated by-product gas recirculation as a combustion heat source. A techno-economic assessment was conducted for system scales from 10 kW to 10 MW, demonstrating the effect of reduced minimum hydrogen selling prices from 7.03 USD kg(-1) at small modular scales to 3.98 USD kg(-1) at larger industrial scales. Sensitivity analyses indicate that hydrogen selling prices may reduce even further (up to 50 %). The suggested hydrogen production route from green NH3 demonstrates superior CO2 reduction ranging from 78 % to 95 % in kg CO2 (kg H-2)(-1) compared to biomass gasification and steam methane reforming. These findings can be used as a basis for following economic and policy studies to further validate the effectiveness of the suggested system and process for H-2 production from NH3