CRUW Mechanical Pulping: Sub-project 10, enzyme treatment of chips for energy reduction in TMP

In order to evaluate the possibilities of using enzymes for pre-treating softwood chips as a means of lowering the energy demand in mechanical pulping, impregnation and refining trials were performed using a set of different enzymes. The enzymes tested pectinase, xylanase and mannanase gave increased sugar release in the impregnation trials indicating that most of the sugar released occurred in the first 60 minutes and that activities thereafter seemed to level off. Refining trials using a small Wing refiner showed that for chips treated for 60 minutes with pectinase, xylanase and mannanase no energy savings to a given freeness level was observed. The property development was similar to that of reference pulps in the case of pectinase and xylanase while for chips treated with mannanase a less favourable development of the tensile index was noted. For chips treated for two hours, using xylanase or pectinase, energy savings could be observed for pectinase treated chips down to a freeness level of 200 CSF. However when refined further, the properties approached those of the reference pulp. Considering the much higher enzymatic activity reached when the initial fibre material was further disintegrated it is assumed that the possibilities for enzymes to attack desired structures of the intact fibre wall may have been too few even in the case of Impressafiner treated material

Application of enzymes for pre-treatment of wood chips for energy efficient thermomechanical pulping

Thermomechanical pulping (TMP) is a highly energy intensive process where most of the energy is used in therefining of chips to fibres. Various ways of reducing the energy consumption have earlier been studied, for examplechange of refiner pattern, addition of various chemicals, and also some biochemical implementation in the form of fungus and enzymes. This study includes pre-trials with the enzymes pectin lyase and pectin esterase,multipectinase, xylanase, and mannanase. The results are studied via a reducing sugar assay, an enzymatic assayusing spectrophotometry, and capillary zone electrophoresis. The study also includes results from a pilot scalerefining with multipectinase, xylanase, and mannanase, performed with a wing refiner at Helsinki University.Reductions of energy consumption in TMP by pre-treatment of Norwegian spruce chips are investigated and apotential reduction of energy consumption of 6 % is indicated

Reduced myelotoxicity with sustained tumor concentration of radioimmunoconjugates in rats after extracorporeal depletion.

The aim of this study was to evaluate the possibility of decreasing the myelotoxicity associated with radioimmunotherapy (RIT) by extracorporeal depletion of radioimmunoconjugates (RIC) from the circulation. The optimal combination of radionuclide and the time interval between injection of the RIC and the subsequent extracorporeal depletion procedure was assessed in immunocompetent rats, with respect to both myelotoxicity and tumor concentration of RIC. Methods: Rats were injected with (177)tumor Y-90-labeled antibody conjugate (mAb-DOTA-biotin) (mAb is monoclonal antibody; DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N",N'''-tetraacetic acid) and subjected to removal of the conjugate from the circulation by extracorporeal affinity adsorption treatment (ECAT) 12, 24, or 48 h after injection. Myelotoxicity was assessed by analysis of blood parameters for 10 wk. The effect of ECAT on the tumor concentration of RIC was evaluated in parallel by scintillation camera imaging in rats injected with In-111-labeled RIC. Results: ECAT reduced the blood content of RIC by 95%. Thus, myelotoxicity was significantly milder in animals subjected to ECAT than that in controls. The timing of ECAT influenced the rate and level of bone marrow recovery, with an earlier recovery in animals subjected to ECAT early after injection. The toxicity-reducing effect of ECAT was more distinct in animals injected with Lu-177-labeled RIC than in animals injected with 90Y-labeled RIC. Scintillation camera imaging of tumors before and after ECAT revealed that subjecting animals to ECAT at 12 h after injection considerably reduced the total activity in tumors (34%), whereas the effect was lower at both 24 h (18%) and 48 h (18%) after injection. Conclusion: ECAT can efficiently reduce myelotoxicity associated with RIT, and the concentration of RIC in tumor can be sustained, provided ECAT is performed at an optimal time after antibody administration. The choice of radionuclide for RIT in combination with ECAT is important, as the physical half-life is crucial for the toxicity-reducing potential of ECAT at a specific time

Optimisation of flight routes for reduced climate impact (OP-FLYKLIM)

The OP-FLYKLIM project investigated the potential to reduce the climate impact of aviation through climate optimization of flight routes to reduce the high-altitude effects of aviation with a focus on climate forcing from contrails and contrail cirrus under Scandinavian conditions. We have developed a calculation methodology where areas with potential to form persistent contrails are identified. The duration and climate forcing of contrails and contrail cirrus in these areas are calculated using data from SMHI's meteorological forecast model. Information on the position and climate forcing potential of these areas has been used to quantify climate forcing of flights on selected routes over a period of several months, and to test optimization of route planning for reduced climate effect with the flight planning system used by the airline Novair. Climate forcing from contrails and contrail cirrus during the flight calculated with the OP-FLYKLIM methodology is compared with calculations of climate forcing from the CO2 emitted from combustion of the jet fuel. This enables a direct comparison of the climate benefit of avoidance of contrail formation with its fuel penalty. In the future this method could be deployed in flight planning systems to enable climate optimization. The method can also be used in cost-benefit analyses of climate-optimized flight planning. We have also investigated several issues that are important for route optimization in general and for correct assessment of whether persistent contrails occur. Meteorological models of good quality in terms of forecasts of winds, temperature and humidity at flight altitude is of great importance both for ordinary route planning and for climate optimization. In OP-FLYKLIM, SMHI has tested streaming data from aircraft (so-called Mode-S EHS data) through air traffic control radars and local data receivers directly to their operational forecast model, which showed improved quality of forecasts.A persistent contrail occurs only if the humidity in the area of the flight is supersaturated relative to ice but is not already containing clouds. In the project, we have thus investigated the distribution of ice-saturated areas across Scandinavia as an average over several years using data from the ECMWF global numerical weather prediction (NWP) model. The results show a quite high potential for the formation of persistent contrails and thus for high-altitude effects in the area. Comparison to published data on the frequency of occurrence of ice supersaturated layers over Sweden and Europe indicate that observations and model data are broadly consistent. However, when comparing to observed relative humidity with respect to ice (RHI) from radiosondes directly it becomes clear that both the ECMWF model and the MetCoOp model used by SMHI for short range forecasts underestimate RHI near the tropopause, where most flights take place. As an additional means to evaluate the performance of NWP models with respect to ice supersaturation SMHI initiated observations of contrails by their climate observers. The observations were then matched against flights in the area and RHI calculated by the SMHI forecast model to determine if observations of persistent contrails also corresponded to ice supersaturation in the model. In agreement with the evaluation against radiosondes it was found that the NWP model underestimated RHI in connection with observed contrails. A correct calculation of fuel consumption and emissions during the flight is a prerequisite both for calculating its high-altitude effects and for monitoring of aviation emissions by national and international authorities. In OP-FLYKLIM the fuel consumption calculated with FOI3 methodology, used for the Swedish reporting of the national emissions from aviation to the UNFCCC and other international reporting obligations, has been compared with true fuel consumption obtained from data from the flight data recorder (FDR data) onboard aircraft on several routes. Comparison showed differences below 10% that could be explained by differences between route plans and type of aircraft in the FDR data and the FOI calculation, respectively

Optimisation of flight routes for reduced climate impact (OP-FLYKLIM)

The OP-FLYKLIM project investigated the potential to reduce the climate impact of aviation through climate optimization of flight routes to reduce the high-altitude effects of aviation with a focus on climate forcing from contrails and contrail cirrus under Scandinavian conditions. We have developed a calculation methodology where areas with potential to form persistent contrails are identified. The duration and climate forcing of contrails and contrail cirrus in these areas are calculated using data from SMHI's meteorological forecast model. Information on the position and climate forcing potential of these areas has been used to quantify climate forcing of flights on selected routes over a period of several months, and to test optimization of route planning for reduced climate effect with the flight planning system used by the airline Novair. Climate forcing from contrails and contrail cirrus during the flight calculated with the OP-FLYKLIM methodology is compared with calculations of climate forcing from the CO2 emitted from combustion of the jet fuel. This enables a direct comparison of the climate benefit of avoidance of contrail formation with its fuel penalty. In the future this method could be deployed in flight planning systems to enable climate optimization. The method can also be used in cost-benefit analyses of climate-optimized flight planning. We have also investigated several issues that are important for route optimization in general and for correct assessment of whether persistent contrails occur. Meteorological models of good quality in terms of forecasts of winds, temperature and humidity at flight altitude is of great importance both for ordinary route planning and for climate optimization. In OP-FLYKLIM, SMHI has tested streaming data from aircraft (so-called Mode-S EHS data) through air traffic control radars and local data receivers directly to their operational forecast model, which showed improved quality of forecasts.A persistent contrail occurs only if the humidity in the area of the flight is supersaturated relative to ice but is not already containing clouds. In the project, we have thus investigated the distribution of ice-saturated areas across Scandinavia as an average over several years using data from the ECMWF global numerical weather prediction (NWP) model. The results show a quite high potential for the formation of persistent contrails and thus for high-altitude effects in the area. Comparison to published data on the frequency of occurrence of ice supersaturated layers over Sweden and Europe indicate that observations and model data are broadly consistent. However, when comparing to observed relative humidity with respect to ice (RHI) from radiosondes directly it becomes clear that both the ECMWF model and the MetCoOp model used by SMHI for short range forecasts underestimate RHI near the tropopause, where most flights take place. As an additional means to evaluate the performance of NWP models with respect to ice supersaturation SMHI initiated observations of contrails by their climate observers. The observations were then matched against flights in the area and RHI calculated by the SMHI forecast model to determine if observations of persistent contrails also corresponded to ice supersaturation in the model. In agreement with the evaluation against radiosondes it was found that the NWP model underestimated RHI in connection with observed contrails. A correct calculation of fuel consumption and emissions during the flight is a prerequisite both for calculating its high-altitude effects and for monitoring of aviation emissions by national and international authorities. In OP-FLYKLIM the fuel consumption calculated with FOI3 methodology, used for the Swedish reporting of the national emissions from aviation to the UNFCCC and other international reporting obligations, has been compared with true fuel consumption obtained from data from the flight data recorder (FDR data) onboard aircraft on several routes. Comparison showed differences below 10% that could be explained by differences between route plans and type of aircraft in the FDR data and the FOI calculation, respectively