Co-hydrothermal carbonization of swine manure and lignocellulosic waste: a new strategy for the integral valorization of biomass wastes

Co-hydrothermal carbonization (co-HTC) is a promising strategy to improve hydrothermal carbonization (HTC) of low-quality wastes. HTC of swine manure (SM), with high N (2.9 wt%), S (0.7 wt%) and ash (22.6 wt%) contents, as well as low C (35.6 wt%) and higher heating value (HHV; 14.3 MJ kg−1), resulted in a hydrochar with unsuitable characteristics as a solid fuel. Co-HTC of SM and garden and park waste (GPW) improved hydrochar properties (C content (43 – 48 wt%) and HHV (18 – 20 MJ kg−1), and decreased N (∼2 wt%), S (50 wt%) during co-HTC resulted in a hydrochar similar to that obtained from GPW. The co-HTC increased nutrient migration to the process water, which allowed the precipitation of salt with high P (7.8 wt%) and negligible heavy metal content. Anaerobic digestion of co-HTC process water allowed high organic matter removal (up to 65%), and methane production (315 – 325 mL CH4 g-1CODadded). Gross energy recovery by HTC and anaerobic digestion was 5 – 6-fold higher than anaerobic treatment of feedstocks. Therefore, co-HTC of SM and GPW with a ratio > 50% GPW proved to be a suitable approach to valorize and manage SM and obtain value-added products (hydrochar, mineral fertilizer and methane)Authors greatly appreciate funding from Spain’s MICINN (PID2019- 108445RB-I00), MINECO (PDC2021-120755-I00 and TED2021- 130287B-I00), Madrid Regional Government (Project S2018/EMT4344), and Grupo Kerbest Company. R.P. Ipiales acknowledges the financial support from the Community of Madrid (IND2019/ AMB17092) and Arquimea Agrotech Compan

Energy recovery from garden and park waste by hydrothermal carbonisation and anaerobic digestion

Hydrothermal carbonisation (HTC) can transform wet lignocellulosic biomass, which is not considered an effective biofuel for energy production at the industrial level, into a carbonaceous product called hydrochar (HC) that is suitable for combustion and a process water (PW). PW is an interesting by-product that can be valorised for biogas production via anaerobic digestion (AD). This study presents a new approach for the valorisation of garden and park wastes (GPW) by integrating HTC to generate HC for energy production, while PW is subjected to AD for biogas production. The hydrothermal treatment was performed at 180, 210, and 230 °C, yielding HC with improved physicochemical properties, such as an elevated higher heating value (21–25 MJ kg−1); low ash (<5 wt.%), nitrogen (1.3 wt.%), and sulphur (0.2 wt.%) contents; better fuel ratio (0.4–0.6); and a broad comprehensive combustibility index (8.0×10−7 to 9.6×10−7 min−2 °C−3). AD of the generated PW was conducted under mesophilic conditions (35 °C), resulting in a methane production in the range of 253–326 mL g−1 CODadded and COD removal of up to 65%. The combination of HTC and AD allowed the recovery of 91% and 94% of the energy content feedstock, as calculated from the combustion of HC and methane, respectivelyThe authors gratefully acknowledge funding from Spain’s MINECO (PID2019-108445RB-I00; PDC2021-120755-I00) and the Comunidad de Madrid (Project S2018/EMT-4344). R. P. Ipiales acknowledges financial support from the Comunidad de Madrid (IND2019/AMB-17092) and the Arquimea-Agrotech Compan

Determining R-parity violating parameters from neutrino and LHC data

In supersymmetric models neutrino data can be explained by R-parity violating operators which violate lepton number by one unit. The so called bilinear model can account for the observed neutrino data and predicts at the same time several decay properties of the lightest supersymmetric particle. In this paper we discuss the expected precision to determine these parameters by combining neutrino and LHC data and discuss the most important observables. We show that one can expect a rather accurate determination of the underlying R-parity parameters assuming mSUGRA relations between the R-parity conserving ones and discuss briefly also the general MSSM as well as the expected accuracies in case of a prospective e+ e- linear collider. An important observation is that several parameters can only be determined up to relative signs or more generally relative phases.Comment: 13 pages, 13 figure

Variational collocation for systems of coupled anharmonic oscillators

We have applied a collocation approach to obtain the numerical solution to the stationary Schr\"odinger equation for systems of coupled oscillators. The dependence of the discretized Hamiltonian on scale and angle parameters is exploited to obtain optimal convergence to the exact results. A careful comparison with results taken from the literature is performed, showing the advantages of the present approach.Comment: 14 pages, 10 table

Broken R-parity, stop decays, and neutrino physics

We discuss the phenomenology of the lightest stop in models where R-parity is broken by bilinear superpotential terms. In this class of models we consider scenarios where the R-parity breaking two-body decay ~t_1->\tau^+b competes with the leading three-body decays such as ~t_1->W^+b~\chi^0_1. We demonstrate that the R-parity violating decay can be sizable and in some parts of the parameter space even the dominant one. Moreover we discuss the expectations for \~t_1->\mu^+b and ~t_1->e^+b. The recent results from solar and atmospheric neutrinos suggest that these are as important as the tau bottom mode. The \~t_1->l^+b decays are of particular interest for hadron colliders, as they may allow a full mass reconstruction of the lighter stop. Moreover these decay modes allow cross checks on the neutrino mixing angle involved in the solar neutrino puzzle complementary to those possible using neutralino decays. For the so--called small mixing angle or SMA solution ~t_1->e^+b should be negligible, while for the large mixing angle type solutions all ~t_1->l^+b decays should have comparable magnitude.Comment: 51 pages, 6 figures, LaTeX2e and RevTeX4, published versio

Integration of hydrothermal carbonization and anaerobic digestion for energy recovery of biomass waste: an overview

Hydrothermal carbonization is emerging as a promising eco-friendly technology for the management of wet biomass wastes through energy recovery. It avoids drying of the feedstock and operates at a much lower temperature than conventional thermal conversion technologies, giving rise to a carbonaceous solid, hydrochar, of improved fuel quality with respect to the starting biomass. However, the aqueous fraction resulting from this process, the so-called process water, represents a troublesome secondary waste requiring effective treatment because of the high chemical oxygen demand and the presence of varying amounts of nutrients. Anaerobic digestion appears as a potential solution allowing significant reduction of the organic load while producing methane-rich biogas, thus contributing to energy recovery. Integrating hydrothermal carbonization and anaerobic digestion is gaining interest in the literature. This review compiles the reported studies on the application of hydrothermal carbonization coupled with anaerobic digestion for energy recovery of different biomass wastes, analyzing the energy balances. The main characteristics of the resulting HC and the methanogenic potential of the process waters are reviewed in connection with the operating conditions, as well as the possibility of nutrient recovery. Life cycle assessment and economic studies are includedThe authors gratefully acknowledge funding from Spain’s MINECO (PID2019-108445RB-I00) and the Comunidad de Madrid (Project S2018/EMT-4344). R. P. Ipiales acknowledges financial support from the Comunidad de Madrid (IND2019/AMB-17092) and the Arquimea Biotech Compan

Spontaneous R-Parity violation bounds

We investigate bounds from tree-level and one-loop processes in generic supersymmetric models with spontaneous R-parity breaking in the superpotential. We analyse the bounds from a general point of view. The bounds are applicable both for all models with spontaneous R-parity violation and for explicit bilinear R-parity violation based on general lepton-chargino and neutrino-neutralino mixings. We find constraints from semileptonic B, D and K decays, leptonic decays of the mu and tau, electric dipole moments, as well as bounds for the anomalous magnetic moment of the muon.Comment: 22 page

MAXI J1659-152: the shortest orbital period black-hole binary

Following the detection of a bright new X-ray source, MAXI J1659-152, a series of observations was triggered with almost all currently flying high-energy missions. We report here on XMM-Newton, INTEGRAL and RXTE observations during the early phase of the X-ray outburst of this transient black-hole candidate. We confirm the dipping nature in the X-ray light curves. We find that the dips recur on a period of 2.4139+/-0.0005 hrs, and interpret this as the orbital period of the system. It is thus the shortest period black-hole X-ray binary known to date. Using the various observables, we derive the properties of the source. The inclination of the accretion disk with respect to the line of sight is estimated to be 60-75 degrees. The companion star to the black hole is possibly a M5 dwarf star, with a mass and radius of about 0.15 M_sun and 0.23 R_sun, respectively. The system is rather compact (orbital separation is about 1.35 R_sun) and is located at a distance of roughly 7 kpc. In quiescence, MAXI J1659-152 is expected to be optically faint, about 28 mag in the V-band.Comment: 5 pages, 4 figures, to be published in the proceedings of the 4th International MAXI Workshop `The First Year of MAXI: Monitoring variable X-ray sources', 2010 Nov 30 - Dec 2, Tokyo, Japa

Penetrating the Deep Cover of Compton Thick Active Galactic Nuclei

We analyze observations obtained with the Chandra X-ray Observatory of bright Compton thick active galactic nuclei (AGNs), those with column densities in excess of 1.5 x 10^{24} cm^{-2} along the lines of sight. We therefore view the powerful central engines only indirectly, even at X-ray energies. Using high spatial resolution and considering only galaxies that do not contain circumnuclear starbursts, we reveal the variety of emission AGNs alone may produce. Approximately 1% of the continuum's intrinsic flux is detected in reflection in each case. The only hard X-ray feature is the prominent Fe K alpha fluorescence line, with equivalent width greater than 1 keV in all sources. The Fe line luminosity provides the best X-ray indicator of the unseen intrinsic AGN luminosity. In detail, the morphologies of the extended soft X-ray emission and optical line emission are similar, and line emission dominates the soft X-ray spectra. Thus, we attribute the soft X-ray emission to material that the central engines photoionize. Because the resulting spectra are complex and do not reveal the AGNs directly, crude analysis techniques such as hardness ratios would mis-classify these galaxies as hosts of intrinsically weak, unabsorbed AGNs and would fail to identify the luminous, absorbed nuclei that are present. We demonstrate that a three-band X-ray diagnostic can correctly classify Compton thick AGNs, even when significant soft X-ray line emission is present. The active nuclei produce most of the galaxies' total observed emission over a broad spectral range, and much of their light emerges at far-infrared wavelengths. Stellar contamination of the infrared emission can be severe, however, making long-wavelength data alone unreliable indicators of the buried AGN luminosity.Comment: To appear in ApJ, September 1, 200