Biochar as a soil amendment and carbon sink becomes in last period one of the vast, interesting product of slow pyrolysis. Simplest and most used industrial process arrangement is a production of biochar and heat at the same time. Proposed mass and heat balance model consist of heat consumers (heat demand side) and heat generation-supply side. Direct burning of all generated uncondensed volatiles from biomass provides heat. Calculation of the mass and heat balance of both sides reveals the internal distribution of masses and energy inside process streams and units. Thermodynamic calculations verified not only the concept but also numerical range of the results. The comparisons with recent published scientific and vendors data prove its general applicability and reliability. The model opens the possibility for process efficiency innovations. Finally, the model was adapted to give more investors favorable results and support techno-economic assessments entirely.
Among other applications, electroporation is used for the inactivation of pathogens and extraction of substances from microorganisms in liquids where large scale flow systems are used. The aim of our work was therefore to test a pulse generator that enables continuous pulsed electric field (PEF) treatment for Escherichia coli inactivation and microalgae lipid extraction. In the continuous flow PEF system, the flow rate was adjusted so that each bacterial cell received a defined number of pulses. The results of PEF flow treatment showed that the number of pulses influences E. coli inactivation to the same extent as in the previously described cuvette system, i.e., batch system. The continuous flow PEF system was also tested and evaluated for lipid extraction from microalgae Chlorella vulgaris. In control experiments, lipids were extracted via concentration of biomass, drying and cell rupture using pressure or an organic solvent. In contrast, electroporation bypasses all stages, since cells were directly ruptured in the broth and the oil that floated on the broth was skimmed off. The initial experiments showed a 50% oil yield using the electroporation flow system in comparison to extraction with organic solvent.
Thermo-gravimetric analysis (TGA) of volatilization reaction kinetics for 50 wt.% mixtures of plastics (PE) and biomass (wood pellets) as well as for 100 wt.% plastics was conducted to predict decomposition times at 850 °C and 900 °C using iso-conversional model method. For mixtures, agreement with the residence time of dual fluidized bed (DFB) reactor, treated as continuous stirred-tank reactor (CSTR), was obtained at large conversions. Mono-gasification of plastics and its co-gasification with biomass were performed in DFB pilot plant, using olivine as heterogeneous catalyst and heat transfer agent. It was found that cogasification led to the successful thermochemical conversion of plastics as opposed to mono-gasification. Unknown flow rates were determined applying nonlinear regression to energy and mass balances acknowledging combustion fuel, air, steam, feedstock, but also exiting char, tar, steam and other components in DFB gasification unit. Water–gas shift equilibrium and methanol synthesis requirements were incorporated into gasification model, based on measurements.
Effectively implementing various energy and environmental policies contributesto the acceleration of energy performance, a reduction in negative environmental impacts, and increased deployment of renewable resources. The MEEMS (municipal energy and environmental management system) performs the almost inconceivable role of accomplishing prerequisite targets at the national level and, consequently, the European and World levels also. Therefore, a proper infrastructure for MEEMS needs to be effectively applied in order to implement policy initiatives. A novel organisational framework of MEEMS is proposed and is constituted upon three pillars: integration of the municipal metabolism approach, the KBS (knowledge-based system), and the MTIS (municipal technology innovation system). By properly addressing the dynamics of the MEES (municipal energy and environmental system), and the new conceptual organisation of MEEMS, a need for the inclusion of innovative elements can be defined regarding support mechanisms. Integration of the end-user approach defines the fundamental orientation of modern MEEMS. This new concept paves a pathway towards an intelligent energy and environmental system. This paper describes an implementation of the new conceptual design of MEEMS within the urban municipality energy system of Ptuj, Slovenia.
A model acknowledging reaction kinetics and thermal conduction during waste end-of-life (ELT) tyre pyrolysis was developed based on the individual consideration of elastomers, namely natural (NR), butadiene (BR) and styrene-butadiene (SBR) rubber; fabric, that is rayon, nylon and aramid; and wire. External diffusional and thermal film resistances proved to be negligible during the thermal cracking. An algorithm was developed to extract pre-exponential factors, activation energies, the orders of reactions, the enthalpies of reactions, and transport parameters. The pyrolysis of various formulations at different volumetric flow rates and heating rates was monitored by thermogravimetry (TG) and differential scanning calorimetry (DSC), whereas the pertinent thermodynamic properties (density, specific heat capacity, and thermal conductivity and diffusivity) were determined separately. The un-decomposable weight fraction containing carbon black, char and ash was 39% for the investigated rubber and 13% for the fabric formulation. The sensitivity analysis of the pyrolysis on compound and process(operating) conditions was performed. The obtained results (taking intoaccount their drawbacks) with the additional measurements and modelling may be used for the thermo-chemical treatment reactor scale-up and optimization, and consequently, a suitable design of energy and products recovery instead of disposal or landfilling, thus minimizing hazardous waste and contamination to soil and water resources.