A successful co-gasification of plastics and biomass was achieved in the 100 kW dual fluidized bed (DFB) gasification pilot plant. The results of a pilot plant experiment were used as a sound basis for scale-up prediction to 750 kW semiindustrial DFB plant. By an eightfold increase of mass and heat flows a rather simplified co-gasification process was predicted. Namely, the losses occurring in gasification plants are expected to be relatively smaller in larger plants. The effect of decreased losses was studied with an equilibrium model. Three different situations were simulated with the following fixed values of losses: 70 kW, 115 kW and 160 kW. The model showed an increase in fuel conversion when losses were reduced.
Chemical and physical parameters of the aqueous polyurethane dispersion (PUD) were studied after the synthesis. A prepolymer mixing process with a limited-chain extension step was used in order to examine the polymer and dispersion behavior with respect to the ageing time. Measurements of free isocyanate groups were performed with the aid of Fourier transform infrared spectroscopy (FT-IR). The pseudo-first-order kinetics of NCO disappearance was proposed and the value of the corresponding constant was determined. Additionally, particle size, particle size distribution, pH, conductivity and molecular mass were monitored and compared.
The objective of this work was to increase laccase production by Pleurotus ostreatus PLAB through culture medium optimization using solid-state culture conditions. Increased laccase activity was obtained through the design of experiments (DOE) using the Taguchi orthogonal array (OA). Seven factors, viz. lignocellulose, glucose, yeast extract, peptone, KH2PO4, MgSO4 · 7H2O and MnSO4 · H2O at three levels and pH at two levels with OA layout of L18 (21 × 37) were selected for the proposed experimental design using Minitab 17 software. Data analysis showed that lignocellulose (20%) and glucose (10 g L-1) had a positive effect, whereas KH2PO4, MgSO4 · 7H2O and MnSO4 · H2O did not have a significant effect on laccase production. Taguchi OA analysis showed that pH 6, lignocellulose 20%, glucose 10 g L-1, yeast extract 6 g L-1, peptone 15 g L-1, KH2PO4 3 g L-1, MgSO4 · 7H2O 0.5 g L-1 and MnSO4 · H2O 0.1 g L-1 were the optimal conditions to maximize laccase production. The model predicted a 30.37 U g-1 dry wt., which agreed with the experimentally obtained laccase activity 29.15 U g-1 dry wt. at optimal conditions.
Extraction of sugar solution from sugar beet cossettes has been studied at different parameters of electric pulses, with electric field intensities varying from 0.52 to 1.52 kV/cm. Sugar beet has been exposed to different number of electric pulses of different duration. Experiments where the only treatment was compressive load gave us maximum juice yield of 30.64 %, with PEF treatment added juice yield rose to a maximum of 80.32%. The whole process lasted 30 minutes. The first 5 minutes we pressed with pressure of 9.254 bars, then electric pulses were applied, followed by additional 25 minutes of pressing. To compare juice yields and specific energy consumption, we also performed experiments replacing PEF treatment with more established thermal treatment at temperatures 30, 40, 50, 60, 72 °C.
In addition to the established procedure incineration in cement production plant, it makes sense to look for and develop new technological processes of finishing pellets or use their organic share. Pyrolysis, as a waste recovery process, is useful for recycling or obtaining of organic matter and nutrients (P, K, N). By using two different techniques, we carried out an experiment of pyrolysis pellets: i) laboratory advanced thermogravimetric analysis TG / DTG / DTA / QMS in an inert atmosphere (argon, 99.999% by volume) at a temperature regime from T(room) to T = 1500 ° C, the mass of ground pellets about 50 mg, the particle size to 100 µm, and ii) a semi-pilot test of the performance of pyrolysis mass of pellets (no grinding) from 400 g to 500 g at a maximum temperature of 600 ° C and a pressure depression -200 mbar without bubbling. With the laboratory thermogravimetric analysis TG / DTG (inert atmosphere, thermal load for 60 minutes at 450 ° C and 60 minutes at 900 ° C) were prepared the appropriate amount of the residue (biochar), which was determinated the physicochemical parameters by further experimentation, the content of elements, water solubility of the nutrients (P and K) and the properties of the leachate. For a more detailed characterization were made the advanced analytical techniques (XRD and SEM-EDS).