Production of BioSNG from waste derived syngas: Pilot plant operation and preliminary assessment

Bio-substitute natural gas (or BioSNG) produced from gasification of waste fuels and subsequent methanation of the product gas could play a crucial role in the decarbonisation of heating and transportation, and could be a vital part of the energy mix in the coming decades. The BioSNG demonstration plant described in this paper seeks to prove the technical feasibility of the thermal gasification of waste to renewable gas, through a preliminary experimental programme to take an existing stream of syngas, methanate it and show that it can be upgraded to gas grid quality requirements. The syngas used in the project is a waste-derived syngas from a two-stage fluidised bed - plasma pilot facility, which is then converted and upgraded in a new, dedicated conversion and clean up plant. Extensive trials were undertaken on methanation and gas upgrading units for over 60 h of continuous operation. The fundamentals of a once-through methanation process train have been established on the demonstration facility and a model built to extend the analysis over different operational parameters. Over the trials, methane outputs of greater than 50 kW_th output were routinely produced from three methanation reactors in series, with a total CO conversion exceeding 90% at pressures as low as atmospheric, in line with kinetic model predictions. Retention of CO₂ as well as adequate partial pressure of H₂O in the process stream was important for process control. The plant provided demonstration of the efficacy of a PSA system for separation of CO₂ (99% removal efficiency) as well as the potential to remove a proportion of residual H₂, N₂ and CO, although this was associated with appreciable CH₄ slip. The process can be optimized primarily by reducing inlet temperature to methanation reactors, controlling syngas composition and using adequate steam to carbon ratio, depending on the type of waste. This information can be used to inform the design and economics of subsequent planned commercial plants that could significantly increase the potential of renewable gas in the UK and elsewhere in Europe, providing a low cost route to low carbon heat and transport.

Performance analysis of RDF gasification in a two stage fluidized bed-plasma process

The major technical problems faced by stand-alone fluidized bed gasifiers (FBG) for waste-to gas applications are intrinsically related to the composition and physical properties of waste materials, such as RDF. The high quantity of ash and volatile material in RDF can provide a decrease in thermal output, create high ash clinkering, and increase emission of tars and CO2, thus affecting the operability for clean syngas generation at industrial scale. By contrast, a two-stage process which separates primary gasification and selective tar and ash conversion would be inherently more forgiving and stable. This can be achieved with the use of a separate plasma converter, which has been successfully used in conjunction with conventional thermal treatment units, for the ability to 'polish' the producer gas by organic contaminants and collect the inorganic fraction in a molten (and inert) state. This research focused on the performance analysis of a two-stage fluid bed gasification-plasma process to transform solid waste into clean syngas. Thermodynamic assessment using the two-stage equilibrium method was carried out to determine optimum conditions for the gasification of RDF and to understand the limitations and influence of the second stage on the process performance (gas heating value, cold gas efficiency, carbon conversion efficiency), along with other parameters. Comparison with a different thermal refining stage, i.e. thermal cracking (via partial oxidation) was also performed. The analysis is supported by experimental data from a pilot plant.

Phase-locked, time-delayed harmonic pulses for high spectral resolution in the extreme ultraviolet

We present experiments in the time and frequency domains aimed at confirming the measured mutual phase coherence of time-delayed, collinear harmonic pulses. We show that pairs of phase-locked harmonic pulses of medium order can be generated for peak intensities up to ~1.5 10(14)W/cm(2) in xenon, demonstrating the possibility of performing high-resolution spectroscopy in the extreme ultraviolet with Ramsey-like techniques.

T-cell prolymphocytic leukaemia: does the expression of CD8+ phenotype justify the identification of a new subtype? Description of two cases and review of the literature

T-cell chronic lymphocytic leukaemia (T-CLL) has recently been reclassified under the heading of T-cell prolymphocytic leukaemia (T-PLL) because of its unfavourable clinical course, independently of the morphologic features. This rare neoplasm usually shows CD4+/CD8- phenotype. Herein we report on two cases of T-PLL with CD8 expression that correspond to a possible variant of the disease first proposed by Hui et al. in 1987. These cases presented with malignant cells showing immunophenotypic features that can be easily identified and distinguished from other peripheral T-cell leukemias. However, the total number of cases studied is inadequate for defining a discrete clinico-pathologic entity with characteristic clinical features and cytogenetical abnormalities. An international collaboration in which tissue from similar cases is referred to a central pathologist for immunophenotyping and cytogenetical study, and clinical data are centrally compiled, may assist in defining this rare malady as a discrete clinico-pathologic entity.

Accuracy of remote sensing of water temperature by Raman spectroscopy

We present an experimental study of the Raman spectrum of pure and synthetic seawater with respect to its salinity and temperature dependence. Experiments made in the laboratory with both cw and pulsed excitation yield information on the limits and applicability of the technique in actual experiments in the field. We have also performed an experimental analysis to determine the presence of stimulated Raman scattering and its influence on the temperature dependence of the spectrum.

[Ultrasonography in the study of synovial disorders and tendon lesions in rheumatoid arthritis]

Conventional radiology is the main diagnostic tool for the visualization of osteoarticular lesions in rheumatoid arthritis. Articular effusions and popliteal cysts were examined with US. This paper is aimed at proving US capabilities in yielding important information about articular and peri-articular soft tissues in the early phases of rheumatoid arthritis. Over the last 30 months, the shoulder, wrist, hand, knee, and hip of 73 rheumatoid patients were studied by means of US and conventional and microfocal radiography. The patients were divided into 2 groups according to the time of onset of the disease. In group A, US demonstrated early synovial exudative inflammation, whereas conventional and microfocal radiography mainly demonstrated soft tissue swelling. In group B (where the first onset dated back to over 1 year), US demonstrated exudative and proliferative changes, together with recurrences. The authors believe US to be able to recognize the early changes of rheumatoid arthritis: as a matter of fact, US shows articular and periarticular soft tissues abnormalities and allows a differential diagnosis to be made between exudative and proliferative forms.

In vivo and in vitro evidence of an adenosine-mediated mechanism of calcium entry blocker activities

Drugs such as dipyridamole (200 micrograms/kg/min), an adenosine uptake inhibitor, and theophylline (300 micrograms/kg/min), an adenosine receptor antagonist, respectively increased and decreased postischemic hyperemia in normal subjects, as well as in POAD patients. Moreover, dipyridamole pretreatment was able to antagonize the reduction of peak flow induced by nifedipine, and the potentiating effect of flunarizine on postischemic hyperemia was affected significantly by theophylline, thus suggesting a possible interference of calcium entry blocker drugs with the endogenous adenosine system. In a cellular model (polymorphonuclear leukocytes--PMN) the inhibitory effect of calcium entry blockers on stimulated functions (degranulation and free radical production) was highly antagonized by theophylline. Finally, a 1H-NMR spectroscopy study showed a binding interaction between adenosine and flunarizine on the cell membrane. An adenosine-receptor coupling to the calcium entry blocker channels is suggested.

In vitro and in vivo enhancement of vincristine antitumor activity on B16 melanoma cells by calcium antagonist flunarizine

Flunarizine, a calcium antagonist commonly employed in therapy for vascular diseases, enhances the in vitro and in vivo antitumor activity of vincristine on B16 melanoma cells. In the presence of flunarizine higher intracellular levels of vincristine were observed in vitro and for a longer time. B16 melanoma bearing mice treated with both the drugs presented a median survival time that was significantly longer than that of the controls. The possible mechanism of the enhancement is herein discussed.

[Beta-thromboglobulin and fibrinopeptide A in acute myocardial infarction]

Fifty patients suffering from acute myocardial infarction were evaluated for beta-thromboglobulin and fibrinopeptide A (FpA) during the first 12 hours after admission. It has been noted that beta-thromboglobulin levels were higher than normal in most of patients examined, whereas FpA levels were higher only in four cases. On the contrary, after 12 hours beta-thromboglobulin levels were normal in all subjects whereas FpA levels showed the same high values. These results indicate that platelets may play an important role only in the acute phase of infarction and that the thrombus formation, accounted for by presence of fibrinogen derivative, only later might occur.

Effects of a calcium-antagonist (flunarizine) on cancer cell movement and phagocytosis

Flunarizine, a calcium-antagonist drug that binds to calmodulin, was found to inhibit the migration of both B16 melanoma cells and M5076 macrophage-like cancer cells. The migration movement, both under agarose and through a polycarbonate filter membrane, was impaired by the drug. In M5076 macrophage-like cells Fc-dependent as well as Fc-independent phagocytosis were also found significantly reduced by flunarizine. Results are discussed in relationship with the previously observed effects of the drug on the growth rate of B16 melanoma cells in vitro.

Effects of a calcium-antagonist (flunarizine) on the in vitro growth of B16 mouse melanoma cells

Flunarizine, a drug which binds to calmodulin, was found to inhibit both the growth rate and the survival fraction of a B16 mouse melanoma cell line cultured in vitro. Both of these effects, that are dose and time-dependent, occurred at doses which in vitro cause a 50% inhibition of the calmodulin-activated cyclic nucleotide phosphodiesterase prepared from the tumor. Cyclic AMP was increased in treated B16 melanoma cells, while DNA synthesis was inhibited, though the DNA content/cell was increased. The possible mechanisms of the drug's action are discussed herein.