Bio-methane Generation from Biogas Upgrading by Semi-permeable Membranes: An Experimental, Numerical and Economic Analysis☆

Abstract The possibility of upgrading biogas produced by anaerobic digestion of the organic fraction of municipal solid waste (OFMSW) to bio-methane, was investigated with the aid of an experimental apparatus and a numerical model. Different compression pressure and three types of membranes, cellulose acetate (CA), polyamide (PI) and polyaryl-ether-ketone-ketone (PEKK), were investigated. The biogas production and composition turned out to be of about 107 NL/kg OFMSW with a CH 4 and CO 2 content of 60.22%v/v and 38.52%v/v, respectively. The upgrading process requested a membrane surface ranging from 1-1.5m 2 h/m 3 to 3.5-6.5 m 2 h/m 3 in the case of CA and PI, respectively, whereas for PEKK it ranged from 5 to 14.2m 2 h/m 3 . Methane content in the upgraded gas was not lower than 95%. The methane losses in all the analyzed scenarios were around 1% and the upgrading costs ranged between 0.08-0.18 €/Nm 3

Exergetic and Economic Analysis of Energy Recovery from the Exhaust Air of Organic Waste Aerobic Bioconversion by Organic Rankine Cycle

Abstract The amount of heat rejected by the exhaust air generated by the aerobic treatment of organic waste (OW) was investigated with the aim of evaluating the amount of electrical energy recoverable by a micro organic Rankine cycle (micro-ORC). Both an energetic and exergetic analysis were performed along with an evaluation of the investment costs. The investigation of the heat content and composition of the exhaust air was experimentally performed on a full scale facility processing 32,000 tonnes/year of OW. Results shows that the average exhaust air rate is of about 4,000 Nm 3 /h with a temperature of 341 K and a relative humidity of 100%. By cooling thi gaseous stream up to 316 K the net power output of the micro-ORC ranges from about 2 kW to about 20 kW. Contemporary the net electrical efficiency decreases from 5% to about 2% whereas the exergetic efficiency ranges in parallel with the net power output from 11% to 1%. Specific investment ranges from about 2,800 €/kW to about 3,900 €/kW and the cost of the electrical energy results of about 0.1 €/kWh to about 0,13 €/kWh

Analysis of the Energetic Potential Generable from an Hybrid Bioreactor Landfill for Waste Organic Fraction

Abstract The analysis of the amount of landfill gas generable from a full scale hybrid bioreactor landfill was investigated. The waste disposed in the landfill biocells was constituted by the waste organic fraction (WOF) arising from the mechanical pre-treatment of the residual municipal solid waste. The average humidity of the WOF was of about 40% by weight on wet basis whereas the volatile solids (VS) where about 50% by weight on total solids. The average total organic carbon concentration was of about 20% by weight of TS. The landfill gas generation potential of WOF was investigate by a standardized anaerobic test shows an average value of about 180 NL/kgVS. The construction of two full scale hybrid bioreactor landfill biocells was followed and the evolution of the composition of the landfill gas generated investigated. Results shows that in about 12 weeks the gas generated shows a methane concentration that rise rapidly from about 20% by vol. up to 55-60% by vol. In about 4 month of collection for energy recovery the amount of landfill gas generated results of about 36 Nm 3 /tonne significantly higher than the one detected for other traditional landfills

Energy Recovery from Low Temperature Heat Produced During Aerobic Biological Treatment

Abstract The possibility of recovering the heat ejected with the exhaust air arising from the aerobic conversion of organic waste for feeding a micro organic Rankine cycle (ORC) was investigated. This heat was upgraded by the combustion of a given amount of solid recovered fuel (SRF). The exhaust air rate ejected by the aerobic process ranged from 40 to 95 kg/day per each tonne/day of waste processed and the temperature ranged, respectively, from 340 K to 330 K. Calculations refer to a typical aerobic treatment facility able to process 20,000 tonnes of organic waste per year. Maximum efficiency in the utilization of the heat produced by the combustion of SRF, ranging from 14% to 22%, was achieved for ORC operating at a compression ratio from 1.5 to 2.5 and exhaust air temperatures from about 340 to 350 K. Operating the ORC with compression ratios higher than 3.5 and exhaust air temperatures of about 510 K, the power output ranged from about 9 to 12 kW. In these conditions, for the size of the facility investigated, the efficiency of the utilization of the heat generated by the combustion of SRF was from 4% to 7% higher than the ORC thermodynamic efficiency

Capsaicin-Induced Changes in LTP in the Lateral Amygdala Are Mediated by TRPV1

The transient receptor potential vanilloid type 1 (TRPV1) channel is a well recognized polymodal signal detector that is activated by painful stimuli such as capsaicin. Here, we show that TRPV1 is expressed in the lateral nucleus of the amygdala (LA). Despite the fact that the central amygdala displays the highest neuronal density, the highest density of TRPV1 labeled neurons was found within the nuclei of the basolateral complex of the amygdala. Capsaicin specifically changed the magnitude of long-term potentiation (LTP) in the LA in brain slices of mice depending on the anesthetic (ether, isoflurane) used before euthanasia. After ether anesthesia, capsaicin had a suppressive effect on LA-LTP both in patch clamp and in extracellular recordings. The capsaicin-induced reduction of LTP was completely blocked by the nitric oxide synthase (NOS) inhibitor L-NAME and was absent in neuronal NOS as well as in TRPV1 deficient mice. The specific antagonist of cannabinoid receptor type 1 (CB1), AM 251, was also able to reduce the inhibitory effect of capsaicin on LA-LTP, suggesting that stimulation of TRPV1 provokes the generation of anandamide in the brain which seems to inhibit NO synthesis. After isoflurane anesthesia before euthanasia capsaicin caused a TRPV1-mediated increase in the magnitude of LA-LTP. Therefore, our results also indicate that the appropriate choice of the anesthetics used is an important consideration when brain plasticity and the action of endovanilloids will be evaluated. In summary, our results demonstrate that TRPV1 may be involved in the amygdala control of learning mechanisms

Grain-size assessment of fine and coarse aggregates through bipolar area morphology

This paper presents a new methodology for computing grey-scale granulometries and estimating the mean size of fine and coarse aggregates. The proposed approach employs area morphology and combines the information derived from both openings and closings to determine the size distribution. The method, which we refer to as Bipolar Area Morphology (BAM), is general and can operate on particles of different size and shape. The effectiveness of the procedure was validate on a set of 13 classes of aggregates of size ranging from 0.125mm to 16mm and made a comparison with standard, fixed- shape granulometry. In the experiments our model con- sistently outperformed the standard approach and pre- dicted the correct size class with overall accuracy over 92%. Tests on three classes from real samples also con- firmed the potential of the method for application in real scenarios

TRIM8-driven transcriptomic profile of neural stem cells identified glioma-related nodal genes and pathways

Background We recently reported TRIM8, encoding an E3 ubiquitin ligase, as a gene aberrantly expressed in glioblastoma whose expression suppresses cell growth and induces a significant reduction of clonogenic potential in glioblastoma cell lines. Methods we provided novel insights on TRIM8 functions by profiling the transcriptome of TRIM8-expressing primary mouse embryonal neural stem cells by RNA-sequencing and bioinformatic analysis. Functional analysis including luciferase assay, western blot, PCR arrays, Real time quantitative PCR were performed to validate the transcriptomic data. Results Our study identified enriched pathways related to the neurotransmission and to the central nervous system (CNS) functions, including axonal guidance, GABA receptor, Ephrin B, synaptic long-term potentiation/depression, and glutamate receptor signalling pathways. Finally, we provided additional evidence about the existence of a functional interactive crosstalk between TRIM8 and STAT3. Conclusions Our results substantiate the role of TRIM8 in the brain functions through the dysregulation of genes involved in different CNS-related pathways, including JAK-STAT. General significance This study provides novel insights on the physiological TRIM8 function by profiling for the first time the primary Neural Stem Cell over-expressing TRIM8 by using RNA-Sequencing methodology