CO2 credit or energy credit in emission trading?

Emission trading is a good concept and approach to tackle global warming. However, what “currency” or “credit” should be used in the trading has remained a debatable topic. This paper proposed an “Energy Credit” concept as an alternative to the “CO₂ credit” that is currently in place. From the thermodynamic point of view, the global warming problem is an “energy balance” problem. The energy credit concept is thought to be more thermodynamically correct and tackles the core of the global warming problem more directly. The Energy credit concept proposed can be defined as: the credit to offset the extra energy trapped/absorbed in the earth (and its atmosphere) due to the extra anthropogenic emission (or other activities) by a country or company. A couple of examples are given in the paper to demonstrate the concept of the Energy credit and its advantages over the CO₂ credit concept.

Lifecycle cost and CO2 emission comparison of conventional and rationalized bridges

The construction industry consumes a great deal of natural resources and energy in constructing, maintaining and demolishing their products such as buildings and bridges. These activities lead significant impacts on global and regional environments in addition to their economic expenses. In this research, the lifecycle cost (LCC) and lifecycle CO₂ (LCCO₂) emission of newly developed bridges, including the minimized girder, rationalized box-girder and rationalized truss bridges, are quantified and compared with those of the conventional I-girder, box-girder and truss bridges. It was found that the newly developed types of bridges have lower values in both LCC and LCCO₂ than the corresponding conventional bridges do. The effects of span lengths on LCC and LCCO₂ are studied for both conventional and rationalized bridges. The characteristics of LCC and LCCO₂ are investigated over the lifecycle of a bridge including its construction, maintenance and replacement stages.

Simple naphthalimide based anion sensors: deprotonation induced colour changes and CO2 fixation

The 4-amino-1,8-naphthalimide based chemosensors 2, 4 and 6 show striking green-to-purple colour changes due to the deprotonation of the 4-amino moiety on interaction with strongly basic anions such as F⁻: these colour changes reverse gradually with time due to the fixation of atmospheric CO₂ (as HCO₃⁻) yielding 1:1 adducts as demonstrated by X-ray crystallography.

Supercritical CO2 modified organic ionic plastic crystals

The treatment of an organic ionic plastic crystal electrolyte N-methyl-N-ethylpyrrolidinium tetrafluoroborate (P_1,2BF₄) with supercritical CO₂ resulted in a substantial increase in ionic conductivity, especially in the more highly ordered solid phases of the material, and also stabilised the most ordered phase to lower temperatures.

Wool powders used as sorbents to remove Co2+ ions from aqueous solution

The Co2+ sorption of two wool powders was investigated using its radioisotope 57Co (T1/2=271.8 days and γ=122.1 and 136.5 keV) as a tracer. The effects of the type of buffer, the pH value, the contact time and the initial concentration of Co2+ on the sorption behaviour of wool powders were studied. The Co2+ releasing ability of wool powders and the re-use of wool powders to sorb Co2+ were also examined. The optimum sorption of Co2+ by the powders occurred at pH 8 in phosphate buffer and pH 10 in ammonium sulphate buffer. Fourier-transform infrared spectroscopy (FTIR) was used to study the changes in chemical structure of the wool after exposure to both buffer solutions. Compared to the untreated wool fibre, the fine wool powders showed rapid sorption rates and high sorption capacities for Co2+. Co2+ ions were recovered after exposing the Co2+ loaded wool to HCl (0.1 M) and buffer at pH 3 (glycine/sodium chloride). After releasing Co2+ ions from wool powders, the efficiency of wool powders re-used to sorb Co2+ was 80% of that of the fresh wool powders. It is concluded from this study that wool powder can be used as an efficient sorbent to remove and release Co2+ from solution.

Use of electrochemical impedance spectroscopy for study of CO2 corrosion prevention by batch treatment inhibitor films

Electrochemical impedance spectroscopy (EIS) was used to study and evaluate commercial batch treatment inhibitors which are used for protecting oil wells, gas wells, and pipelines from CO2 corrosion, focusing on the evaluation of inhibitor film persistency. It was found that theformation and deterioration of batch treatment inhibitor films were accompanied by typical impedance spectral changes. During the formation of inhibitor films, electrode impedance showed a rapid increase and the Bode phase angle plots also showed a sudden change. Thus, the formation of inhibitor film was a very fast process. During the deterioration of inhibitor films, electrode impedance showed a gradual decrease and the Bode phase angle plots showed changes which characterised the three stages of the inhibitor film deterioration process. The relationships between EIS and corrosion rate are discussed, including comparisons with weight loss measurements. Based on the experimental findings in the present work, a method is suggested for estimating the persistency of inhibitor films by monitoring the characteristic changes in the Bode phase angle plots and by measuring electrochemical charge transfer resistance at the second and third stages of the inhibitor film deterioration process.

Pressure- and heat-induced insertion of CO2 into an auxetic small-pore zeolite

When the small-pore zeolite natrolite is compressed at ca. 1.5 GPa and heated to ca. 110 °C in the presence of CO₂, the unit cell volume of natrolite expands by 6.8% and ca. 12 wt % of CO₂ is contained in the expanded elliptical channels. This CO₂ insertion into natrolite is found to be reversible upon pressure release.

Studies of CO2 corrosion product scales using electrochemical impedance spectroscopy and surface characterisation techniques

Electrochemical impedance spectroscopy (EIS) was used to study carbon dioxide (CO2) corrosion product scales and their effects on further CO2 corrosion. Objectives were to determine the suitability of EIS for studying corrosion scales and to investigate the influence of environmental factors on scale formation. EIS provided useful information about protective abilities and electrochemical properties of corrosion scales. CO2 corrosion scales formed at high-temperature and pressure provided better protection than those formed at low-temperature and pressure. The level of protection of the scale formed at higher temperature and pressure increased with exposure time. EIS results were compared with coupon weight-loss measurements. Scales were analyzed using a combination of Fourier transform infrared (FTIR) analysis, x-ray diffraction (XRD), and electron microscopy

Measurement and solutions to thermal comfort, CO2 and ventilation rates in schools

An Australian research facility, conducted a study on several different school classrooms in regards to their thermal comfort, CO2 levels, air temperature stratification and ventilation rates in a selection of Victorian (Melbourne, Australia) schools during a winter season. A brief literature review reveals similar IAQ problems elsewhere (outside Australia) and suggests several HVAC concepts that provide potential solutions. Our intention is to highlight particular IAQ discrepancies in existing school classroom design resulting from these case study measurements, suggesting construction and mechanical operational conditioning improvements.In particular this research confirms the urgency and necessity of addressing IAQ problems in schools, world wide. Our results of the Australian school classroom measurements are similar to other parts of the world, indicating that CO2 levels, ventilation rates and air temperatures are non-compliant with the standards.