Marine Carbon BiogeochemistryBiogeochemical Cycles and ClimateGlobal Biogeochemical Cycles in the Climate SystemOcean Dynamics and the Carbon CycleLive Long and EvolveBiogeochemistry of Marine Dissolved Organic MatterOcean Biogeochemical DynamicsMarine Ecosystems and Global ChangeBiological OceanographyNitrogen in the SeaBiogeochemistry of EstuariesInteractions of C, N, P and S Biogeochemical Cycles and Global ChangeGlobal EnvironmentComputational Science — ICCS 2004The Oceans and ClimateMarine Microbiome and Biogeochemical Cycles in Marine Productive AreasMetal Ions in Biological Systems, Volume 43 Biogeochemical Cycles of ElementsNitrogen in the Marine EnvironmentIntroduction to Marine BiogeochemistryOcean Circulation and ClimatePrimary Productivity and Biogeochemical Cycles in the SeaThe Biogeochemical Cycle of Silicon in the OceanChemical OceanographyTowards a Model of Ocean Biogeochemical ProcessesOcean Dynamics and the Carbon CycleOcean BiogeochemistryParticle Analysis in OceanographyBiogeochemical CyclesBiogeochemical Dynamics at Major River-Coastal InterfacesThe Ocean Carbon Cycle and ClimateSensitivity of global ocean biogeochemical dynamics to ecosystem structure in a future climateModeling Methods for Marine ScienceAn Introduction to the Chemistry of the SeaEncyclopedia of Ocean SciencesCO2 in Seawater: Equilibrium, Kinetics, IsotopesThe Biogeochemical Cycle of Silicon in the OceanKuroshio CurrentThe Mediterranean Sea in the Era of Global Change 1Ocean Biogeochemical DynamicsOcean Mixing

Ocean Biogeochemical Dynamics

Rechargeable Li-ion battery applications in consumer products are fastly growing, resulting in increasing resources demand: it is for example estimated that battery applications account for nearly 25% of the worldwide cobalt demand in 2007. It is obvious that recycling of batteries may help saving natural resources. However, it is not straightforward to quantify to what extent rechargeable battery recycling saves natural resources, given their complex composition, and the complex international production chain. In this paper, a detailed analysis of a lithium mixed metal oxide battery recycling scenario, where cobalt and nickel are recovered and re-introduced into the battery production chain, is compared with a virgin production scenario. Based on detailed data acquisition from processes spread worldwide, a resource saving analysis is made. The savings are quantified in terms of exergy and cumulative exergy extracted from the natural environment. It turns out that the recycling scenario result in a 51.3% natural resource savings, not only because of decreased mineral ore dependency but also because of reduced fossil resource (45.3% reduction) and nuclear energy demand (57.2%).

Recycling rechargeable lithium ion batteries: Critical analysis of natural resource savings

New technologies, either renewables-based or not, are confronted with both economic and technical constraints. Their development takes advantage of considering the basic laws of economics and thermodynamics. With respect to the latter, the exergy concept pops up. Although its fundamentals, that is, the Second Law of Thermodynamics, were already established in the 1800s, it is only in the last years that the exergy concept has gained a more widespread interest in process analysis, typically employed to identify inefficiencies. However, exergy analysis today is implemented far beyond technical analysis; it is also employed in environmental, (thermo)economic, and even sustainability analysis of industrial systems. Because natural ecosystems are also subjected to the basic laws of thermodynamics, it is another subject of exergy analysis. After an introduction on the concept itself, this review focuses on the potential and limitations of the exergy concept in (1) ecosystem analysis, utilized to describe maximu...

Exergy: Its Potential and Limitations in Environmental Science and Technology

Metal–organic frameworks meet scalable and sustainable synthesis

Although the processing of coal is an ancient problem and has been practiced for centuries, the constraints posed on today's coal conversion processes are unprecedented, and utmost innovations are required for finding the solution to the problem.With a strong demand for an affordable energy supply which is compounded by the urgent need for a CO2 emission control, the clean and efficient utilization of coal presents both a challenge and an opportunity to the current global R&D efforts in this area. This paper provides a historical perspective on the utilization of coal as an energy source as well as describing the progress and challenges and the future prospect of clean coal conversion processes. It provides background on the historical utilization of coal as an energy source, along with particular emphasis on the constraints in current coal conversion technologies. It addresses the energy conversion efficiencies for current coal combustion and gasification processes and for the membrane and looping based novel processes which are currently under development at various stages of testing. The control technologies for pollutants including CO2 in flue gas or syngas are also discussed. The coal conversion process efficiencies under a CO2 constrained environment are illustrated based on data and ASPEN Plus® simulations. The challenges for future R&D efforts in novel coal conversion process development are also presented.

Clean coal conversion processes – progress and challenges

The idea that entropy production puts a constraint on ecosystem functioning is quite popular in ecological thermodynamics. Yet, until now, such claims have received little quantitative verification. Here, we examine three ‘entropy production’ hypotheses that have been forwarded in the past. The first states that increased entropy production serves as a fingerprint of living systems. The other two hypotheses invoke stronger constraints. The state selection hypothesis states that when a system can attain multiple steady states, the stable state will show the highest entropy production rate. The gradient response principle requires that when the thermodynamic gradient increases, the system's new stable state should always be accompanied by a higher entropy production rate. We test these three hypotheses by applying them to a set of conventional food web models. Each time, we calculate the entropy production rate associated with the stable state of the ecosystem. This analysis shows that the first hypothesis holds for all the food webs tested: the living state shows always an increased entropy production over the abiotic state. In contrast, the state selection and gradient response hypotheses break down when the food web incorporates more than one trophic level, indicating that they are not generally valid.

https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2009.0300

Ecosystem functioning and maximum entropy production: a quantitative test of hypotheses

We will discuss the maximum entropy production (MaxEP) principle based on Jaynes' information theoretical arguments, as was done by Dewar (2003 J. Phys. A: Math. Gen. 36 631–41, 2005 J. Phys. A: Math. Gen. 38 371–81). With the help of a simple mathematical model of a non-equilibrium system, we will show how to derive minimum and maximum entropy production. Furthermore, the model will help us to clarify some confusing points and to see differences between some MaxEP studies in the literature.

A discussion on maximum entropy production and information theory

We explain the (non-)validity of close-to-equilibrium entropy production principles in the context of linear electrical circuits. Both the minimum and the maximum entropy production principles are understood within dynamical fluctuation theory. The starting point are Langevin equations obtained by combining Kirchoff’s laws with a Johnson-Nyquist noise at each dissipative element in the circuit. The main observation is that the fluctuation functional for time averages, that can be read off from the path-space action, is in first order around equilibrium given by an entropy production rate.

/pdf/on-the-validity-of-entropy-production-principles-for-linear-51rnhw4259.pdf

Stijn Bruers

Papers

Exergy: Its Potential and Limitations in Environmental Science and Technology

Ecosystem functioning and maximum entropy production: a quantitative test of hypotheses

A discussion on maximum entropy production and information theory

On the Validity of Entropy Production Principles for Linear Electrical Circuits

A thermodynamic perspective on food webs: quantifying entropy production within detrital-based ecosystems.