Biomass potential from agricultural waste for energetic utilization in Greece

The alignment of the Greek national legislation with the corresponding EU legislation has enhanced the national efforts to pursue renewable Combined Heat and Power (CHP) projects. The scope of the present study has been the identification of the available biomass resources and the assessment of their potential. In this paper, we present the results from the administrative regions of Crete, Thessaly, and Peloponnese. The levels of lignocellulosic biomass in Greece are estimated to be 2,132,286 tonnes on an annual basis, values that are very close to the cases of other Mediterranean countries like Italy and Portugal. In respect to the total agricultural residues, Crete produces 1,959,124 tonnes/year and Thessaly produces 1,759,457 tonnes/year. The most significant streams are identified to be olive pits, olive pruning, and cotton ginning remnants, with more than 100,000 tonnes/year each. In the latter part of this manuscript, a case study is presented for the development of a CHP gasification facility in Messenia. The biomass energy potential of the area is very promising, with about 3,800,000 GJ/year. The proposed small-scale gasification technology is expected to utilize 7956 tonnes of biomass per year and to produce 6630 MWh of electricity and 8580 MWh of thermal energy.This research received no external funding

Assessing the removal of heavy metals in industrial wastewater by means of chemical exergy

Presented at the 13th IWA Specialized Conference on Small Water and Wastewater Systems & 5th IWA Specialized Conference on Resources-Oriented Sanitation, 14–16 September, 2016, Athens, Greece.Industrial processes may frequently produce wastewater with high concentrations of heavy metal ions. Heavy metals can be harmful both for the environment and for the human health even in small concentrations. This study has the scope to assess the efficiency of four different sorbent-assisted ultrafiltration methods that were applied for enhancing the treatment of industrial wastewater. Each treatment has different levels of removal success for each heavy metal ion. In the framework of this manuscript chemical exergy is utilized as an evaluating parameter of mass fluxes. The total efficiency of each treatment method is assessed by calculating the total chemical exergy dissipation of each mass flux. All the treatment methods successfully removed more than 96% of copper and lead ions while the performances with respect to nickel and zinc ions removal were more erratic. The ultrafiltration/ bentonite absorption had the best overall performance with a total chemical exergy dissipation of 66.82%, and ultrafiltration/vermiculite absorption had the second best overall performance with 64.29%. The method was able to combine different parameters and return meaningful results that can be used for optimization of wastewater plants treatment management

Kyle Magee: Ad-busting, exclusion and the urban environment

Bird, SP ORCiD: 0000-0002-9591-7932This is an article about freedom of communication, and how it is essential to democracy and the inclusive city.2 This struggle for democratic speech is highlighted by the case of Kyle Magee, a Melbourne activist. Australia is a liberal democracy that prides itself on its ability to protect citizens without a formal Bill of Rights embedded in its Constitution.3 Citizens rely principally on common law freedoms developed over hundreds of years by the judiciary. In recent times the High Court has recognised some implied constitutional rights to political freedoms. Among the implied rights is a right to political communication, which covers actions as well as speech. 4 Political communication generally takes place in the public sphere. The ‘public sphere’ includes both physical public spaces and the media. 5 However, the public sphere is crowded with commercial messages. Therefore, although there may be a right to speak within these spaces, the ability to do so is virtually non-existent without large financial resources

The water-energy-climate nexus concept of “Hydrobattery”: Storing excess Variable Renewable Energy (VRE) at the Canyon Ferry Dam

Hydropower is the renewable energy with the highest power production worldwide. At the same time the output flow of the water that is being used for hydroelectric power production can fluctuate significantly. The ability to “recharge” the dams with water from excess variable renewable energy technologies (VRE) can be used for storage and as a buffer for smoothing the production peaks of VRE. This study presented the idea of the “Hydrobattery” scheme which combines the concepts of “open-loop” and “closed-loop” pumped storage technologies along with the concept of energy storage and water recirculation. The Canyon Ferry Dam was used as a case study and water was modelled to be recirculating back to the Dam from the Helena Valley reservoir. The hydropower production from the Canyon Ferry Dam is below the nominal value of 50 MW and has fluctuated from 34.74 MW up to 41.46 MW for the period between 2014 and 2018. The application of “Hydrobattery” would be able to increase the power output by 2.39–3.39 MW of additional power, and an increase of power production between 5.7% and 9.7%. Also, the concept of “Hydrobattery” can be used as a potential water management system for connected water reservoirs