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Hot water heat stores with stratification are a common technology used in solar energy systems and reuse of waste heat. Adding a PCM module at the top of the water tank would give the system higher storage density, and compensate heat loss in the top layer. The work presented here includes experimental results and numerical simulation of the system using an explicit finite-difference method. Experiments and simulations were carried out using different cylindrical PCM modules. With only 1/16 of the volume of the store being PCM, 3/16 of water at the top of the store was held warm for 50% to 200% longer and the average energy density was increased by 20% to 45%. Furthermore, these 3/16 of water were reheated by the heat from the module after being cooled down in only 20 min.

Available methods for measuring the impact of ocean acidification (OA) and leakage from carbon capture and storage (CCS) on marine sedimentary pH profiles are unsuitable for replicated experimental setups. To overcome this issue, a novel optical sensor application is presented, using off-the-shelf optode technology (MOPP). The application is validated using microprofiling, during a CCS leakage experiment, where the impact and recovery from a high CO2 plume was investigated in two types of natural marine sediment. MOPP offered user-friendliness, speed of data acquisition, robustness to sediment type, and large sediment depth range. This ensemble of characteristics overcomes many of the challenges found with other pH measuring methods, in OA and CCS research. The impact varied greatly between sediment types, depending on baseline pH variability and sediment permeability. Sedimentary pH profile recovery was quick, with profiles close to control conditions 24 h after the cessation of the leak. However, variability of pH within the finer sediment was still apparent 4 days into the recovery phase. Habitat characteristics need therefore to be considered, to truly disentangle high CO2 perturbation impacts on benthic systems. Impacts on natural communities depend not only on the pH gradient caused by perturbation, but also on other processes that outlive the perturbation, adding complexity to recovery.

Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C, 900 °C) and gasification (obtained at 820 °C using a mixture of air and steam as fluidizing agent) of char from sewage sludge fast pyrolysis carried out at 530 ºC. Depending on the extraction conditions (type of acid, extraction time and acid concentration) phosphorus yields of 90% to 100% are reached. Char ash seems to be a renewable resource of phosphorus. It could be an alternative to rock phosphate for fertilizers production. The combination of these processes contributes to the integral exploitation of sewage sludge. Proceedings of the 21st European Biomass Conference and Exhibition, 3-7 June 2013, Copenhagen, Denmark, pp. 500-505

Abstract A heat pump coupled to thermal energy storage (TES) tanks is experimentally tested under simulated summer conditions and the results are presented in this paper. The cold TES tank is used for shifting the cooling load of a small house-like structure. The study evaluates the thermal behaviour of the TES tank for cold storage and the application of the system for space cooling. For the analysis, two different configurations of the tanks are compared: a water tank and a PCM tank. The PCM tank is filled with a commercial macro-encapsulated PCM, which has a phase change temperature of 10 °C. The results point out that the PCM tank is able to supply 14.5% more cold and to maintain the indoor temperature within comfort 20.65% longer than the water tank. However, it needs 4.55 times longer to charge the tank.

This paper presents a preliminary study of the characterization of real waste from slaughterhouses as well as their rendering products (protein and fat) through different pyrolytic techniques: thermogravimetric analysis (TG), analytical pyrolysis in a pyroprobe equipment and hydrothermal liquefaction process (HTL). The experiments have allowed a deeper knowledge about the thermal behavior of these wastes under different conditions: slow pyrolysis up to 800°C (TG), flash pyrolysis at 500°C and room pressure (pyroprobe) and slow pyrolysis at 290°C and 110-130bar (HTL batch reactor). Experiments with each one of the materials (real waste, PAP and fat) as well as some mixtures have been performed. Gas chromatography and mass spectrometry techniques were used to identify the pyrolytic products obtained. The results indicate that fatty acids and fatty esters are the major group obtained in the pyrolysis of fat samples, followed by aliphatic hydrocarbons. In the case of PAP pyrolysis, heterocyclic aromatic compounds, which includes typical products coming from protein degradation, is the major group obtained. Oxygenated aliphatics are also obtained in high amounts. In the case of the HTL experiments, significant glycerine amounts were detected in the aqueous phase. The yield of biocrude obtained under HTL conditions is about 30%, with a high proportion of nitrogenated compounds (amides, pyrrole and pyridine derivatives). Generation of amides is much higher under HTL conditions than in the analytical pyrolysis runs while the proportion of acids is reduced.

Feedbacks between land carbon pools and climate provide one of the largest sources of uncertainty in our predictions of global climate. Estimates of the sensitivity of the terrestrial carbon budget to climate anomalies in the tropics and the identification of the mechanisms responsible for feedback effects remain uncertain. The Amazon basin stores a vast amount of carbon, and has experienced increasingly higher temperatures and more frequent floods and droughts over the past two decades. Here we report seasonal and annual carbon balances across the Amazon basin, based on carbon dioxide and carbon monoxide measurements for the anomalously dry and wet years 2010 and 2011, respectively. We find that the Amazon basin lost 0.48 ± 0.18 petagrams of carbon per year (Pg C yr(-1)) during the dry year but was carbon neutral (0.06 ± 0.1 Pg C yr(-1)) during the wet year. Taking into account carbon losses from fire by using carbon monoxide measurements, we derived the basin net biome exchange (that is, the carbon flux between the non-burned forest and the atmosphere) revealing that during the dry year, vegetation was carbon neutral. During the wet year, vegetation was a net carbon sink of 0.25 ± 0.14 Pg C yr(-1), which is roughly consistent with the mean long-term intact-forest biomass sink of 0.39 ± 0.10 Pg C yr(-1) previously estimated from forest censuses. Observations from Amazonian forest plots suggest the suppression of photosynthesis during drought as the primary cause for the 2010 sink neutralization. Overall, our results suggest that moisture has an important role in determining the Amazonian carbon balance. If the recent trend of increasing precipitation extremes persists, the Amazon may become an increasing carbon source as a result of both emissions from fires and the suppression of net biome exchange by drought.

Aquifer thermal energy storage (ATES) is a cost-effective technology that enables the reduction of energy use and CO2 emissions associated with the heating and cooling of buildings by storage and recovery of large quantities of thermal energy in the subsurface. Reducing the distance between wells in large-scale application of ATES increases the total amount of energy that can be provided by ATES in a given area. However, due to thermal interference the performance of individual systems can decrease. In this study a novel method is presented that can be used to (a) determine the impact of thermal interference on the economic and environmental performance of ATES and (b) optimize well distances in large-scale applications. The method is demonstrated using the hydrogeological conditions of Amsterdam, Netherlands. Results for this case study show that it is cost-effective to allow a limited amount of thermal interference, such that 30–40% more energy can be provided in a given area compared to the case in which all negative thermal interference is avoided. Sensitivity analysis indicates that optimal well distance is moderately insensitive to changes in hydrogeological and economic conditions. Maximum economic benefit compared to conventional heating and cooling systems on the other hand is sensitive, especially to changes in the gas price and storage temperatures.

The influence of two strains of Trichoderma (T. harzianum strain T22 and T. atroviride strain P1) on the growth of lettuce plants (Lactuca sativa L.) irrigated with As-contaminated water, and their effect on the uptake and accumulation of the contaminant in the plant roots and leaves, were studied. Accumulation of this non-essential element occurred mainly into the root system and reduced both biomass development and net photosynthesis rate (while altering the plant P status). Plant growth-promoting fungi (PGPF) of both Trichoderma species alleviated, at least in part, the phytotoxicity of As, essentially by decreasing its accumulation in the tissues and enhancing plant growth, P status and net photosynthesis rate. Our results indicate that inoculation of lettuce with selected Trichoderma strains may be helpful, beside the classical biocontrol application, in alleviating abiotic stresses such as that caused by irrigation with As-contaminated water, and in reducing the concentration of this metalloid in the edible part of the plant.