Use of MEA oxidation intermediates to monitor oxidation conditions during post-combustion capture of CO2

Amine oxidation is a serious concern for post-combustion capture (PCC) of CO2 from fossil-fuel fired power stations. Organic acids are important oxidation products and have been measured in different ratios at different pilot plants. The concentrations of acetate, formate, glycolate and oxalate were measured in samples of degraded monoethanolamine from a variety of PCC pilot plants as well as laboratory-scale degradation experiments. The results suggest that the ratios of monoethanolamine oxidation intermediates (particularly glycolate and oxalate) have potential as process monitoring tools. Ultimately, ratios of these oxidation intermediates could be used to proactively manage and minimise oxidation of amine-based PCC absorbents by indicating the need for oxygen-scavenger addition or alerting operators to imminent increases in oxidative degradation rates

2DH Morphodynamic Time-Dependent Hindcast Modelling of a Groyne System in Ghana

Sediment Transport and Morphodynamic

Medium Term Time-Dependent Morphodynamic Modelling of Beach Profile Evolution in Ada, Ghana

Sediment Transport and Morphodynamic

Carbon negative platform chemicals from waste using enhanced geothermal systems

Australia has ample geothermal resource, however, it is of low-grade heat and requires Enhanced Geothermal Systems (EGS). Integrating heat recovered via EGS into a lignocellulosic biorefinery opens the avenue for countless opportunities in biomass to products industries. In this study, a biorefinery is modelled that uses heat from a supercritical C

Techno-economic evaluation of amine-reclamation technologies and combined CO2/SO2 capture for Australian coal-fired plants

CSIRO's patented CS-Cap process aims at reducing the costs of amine-based post-combustion capture by combining SO2 and CO2 capture using one absorbent in a single absorber column. By avoiding the need for a separate flue gas desulfurization unit, the process offers potential savings for power plants requiring CO2 capture. High-level cost estimates based on lab and pilot data are presented for two amine reclamation techniques i.e. thermal reclamation and reactive crystallisation. Only regeneration via reactive crystallisation reduces CS-Cap costs below base case FGD/SCR-PCC. Cost estimations suggest a potential reduction of 38–44% in the total plant cost when using the CS-Cap process compared to base case. However, the amine reclaimer operating cost governs the overall cost of the CS-Cap process and is highly sensitive to sulfur content. A 50% reduction is observed when SO2 levels reduce from 700 to 200 ppm. Comparing levelised cost of electricity and CO2 avoided costs for CS-Cap against our base case, low sulfur brown coal has a slight (5–7%) cost advantage; however, confirmation requires pilot data on amine recovery. © 202

A review of practical tools for rapid monitoring of membrane bioreactors

The production of high quality effluent from membrane bioreactors (MBRs) arguably requires less supervision than conventional activated sludge (CAS) processes. Nevertheless, the use of membranes brings additional issues of activated sludge filterability, cake layer formation and membrane fouling. From a practical standpoint, process engineers and operators require simple tools which offer timely information about the biological health and filterability of the mixed liquor as well as risks of membrane fouling. To this end, a range of analytical tools and biological assays are critically reviewed from this perspective. This review recommends that Capillary Suction Time (CST) analysis along with Total Suspended and Volatile Solids (TSS/VSS) analysis is used daily. For broad characterisation, total carbon and nitrogen analysis offer significant advantages over the commonly used chemical and biological oxygen demand (COD/BOD) analyses. Of the technologies for determining the vitality of the microbial biomass the most robust and reproducible, are the second generation adenosine-5'-triphosphate (ATP) test kits. Extracellular polymer concentrations are best monitored by measurement of turbidity after centrifugation. Taken collectively these tools can be used routinely to ensure timely intervention and smoother operation of MBR systems. © 2016 Elsevier Ltd

Brown coal dewatering using poly (Acrylamide-co-potassium acrylic) based super absorbent polymers

With the rising cost of energy and fuel oils, clean coal technologies will continue to play an important role during the transition to a clean energy future. Victorian brown coals have high oxygen and moisture contents and hence low calorific value. This paper presents an alternative non evaporative drying technology for high moisture brown coals based on osmotic dewatering. This involves contacting and mixing brown coal with anionic super absorbent polymers (SAP) which are highly crossed linked synthetic co-polymers based on a cross-linked copolymer of acryl amide and potassium acrylate. The paper focuses on evaluating the water absorption potential of SAP in contact with 61% moisture Loy Yang brown coal, under varying SAP dosages for different contact times and conditions. The amount of water present in Loy Yang coal was reduced by approximately 57% during four hours of SAP contact. The extent of SAP brown coal drying is directly proportional to the SAP/coal weight ratio. It is observed that moisture content of fine brown coal can readily be reduced from about 59% to 38% in four hours at a 20% SAP/coal ratio. © 2015 by the authors; licensee MDPI, Basel, Switzerland

Joining forces across projects to have one fully functional ventilation machine, freely reproducible worldwide

880’000 ventilation machine are needed to avoid deaths. 60+ versions of freely / reproducible ventilation machines vital need of ・coordination of open networks and caregivers ・crowdsourced quality assessment ・knowledge for decentralized mass productio

Simulating combined SO2 and CO2 capture from combustion flue gas

The requirement to pre‐treat flue gas prior to the CO2 capture step is an economic challenge when using aqueous amine absorbents for capturing CO2 from coal‐fired power station flue gases. A potentially lower cost alternative is to combine the capture of both CO2 and SO2 from the flue gas into a single process, removing the requirement for the desulfurization pre‐treatment step. The CSIRO's CS‐Cap process uses a single aqueous amine absorbent to capture both of these acid gases from flue gas streams. This paper covers the initial simulation of this process applied to both brown and black coal flue gases. Removal of absorbed SO2 is achieved via reactive crystallization. This is simulated here using a ‘black box’ process, resulting in a K2SO4 product. Different operating conditions have been evaluated that increase the sulfate concentration of the absorbent in the SO2 capture section of the process, which is expected to increase the efficiency of the reactive crystallization step. This paper provides information on the absorption of SO2 into the amine solution, and heat and mass balances for the wider process. This information will be required for further detailed simulation of the reactive crystallization step, and economic evaluation of the CS‐Cap process. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd

Climate driven trends in tree biomass increment show asynchronous dependence on tree-ring width and wood density variation

Tree growth is a key ecosystem function supporting climate change mitigation strategies. However climate change may induce feedbacks on radial growth and wood density, affecting the carbon sequestration capacity of forests. Using a mixed modeling technique long-term trends in radial growth, wood density and above-ground biomass, defined as the product of the annual basal area growth with the wood density, of common beech (Fagus sylvatica) and sessile oak (Quercus petraea) in the Belgian Ardennes, were determined and explained using climate drivers of change. This modeling strategy allowed us to determine if the same conclusions can be drawn when only BAI is considered, as is assumed in most carbon sequestration studies, when looking at long-term trends in carbon sequestration. The models indicate that above-ground biomass increment changes over time are more driven by changes in radial growth than by changes in wood density. Nevertheless, the assumption of constant wood density in most carbon sequestration studies is incorrect. Ignoring wood density results in an underestimation of long-term trends in above-ground biomass increment for beech, and an overestimation of above-ground biomass increment for oak. Interesting is that radial growth is mostly driven by climate variables of the current year, whereas wood density is more driven by the climate variables of the previous year. Beech radial growth and wood density is found to be negatively influenced by drought and positively by water availability. Oak radial growth and wood density is negatively affected by late frost and positively by water availability. The findings of this study suggest that radial growth in combination with wood density should be used in carbon sequestration studies as different climate driven long-term trends in radial growth and wood density are found