Search

Effective municipal solid waste (MSW) management and waste-to-resource recovery has a key potential to play a vital role in economic growth of a country. MSW contains the different items of daily use that makes its composition mix in nature. Different waste-to-energy techniques are already available to treat this waste but these techniques always require some pretreatments such pre-separation and pre-drying of mix MSW that makes these processes less techno-economic to apply on large scales. To provide an effective solution to this problem, potential wet oxidation technique has been reviewed in this study. In the first section, the statistics for MSW generation and composition for different cities in Poland have been presented to show the existence of maximum organic content which can be converted to useful organic compounds. In the later section, the wet oxidation technique and its various aspects have been reviewed in detail to justify the potential of this technique to treat mix MSW at larger scales to produce different valuable products in the context of waste-to-resource recovery. Graphical abstract

Four representative pretreatment methods, water washing (WW), acid washing (AW), dilute acid hydrolysis (DH), and microwave assisted organosolv pretreatment (MOP), were adopted to alter eucalyptus ...

The goal of the work is to determine unknown parameters of reactor heating in the process of biomass solar pyrolysis. The lab-scale reactor is heated by a xenon lamp, but the fraction of heat absorbed by the reactor is unknown, as well as the heat transfer coefficient from the reactor walls to the nitrogen flowing through internal reactor channels, and the overall heat transfer coefficient through the external reactor walls to the surroundings. The missing parameters are impossible to measure, therefore they need to be determined by solving the inverse problem. As the problem is strongly ill-conditioned, since the quantities are directly dependent on each other, two different inverse algorithms were used to retrieve them, namely, the Levenberg-Marquardt method and the Metropolis-Hastings method. The effectiveness of both approaches was assessed and then they were applied to the real data. The inverse problem was implemented in the MatLab software, while validation of the mathematical model and optimisation procedure was carried out with a CFD model built in Ansys Fluent 19.2. Calculations showed that 14.4% of the lamp power penetrates inside the reactor and heat transfer coefficients to the flowing nitrogen equal 8.74 W/m2K and 0.965 W/m2K to the surroundings.

Within the presented paper, different approaches to determine kinetic reaction models governing pyrolysis of three waste biomass types: waste wood (WW), waste straw (WS) and sewage sludge (SS) based on 5 dynamic heating runs (5, 10, 20, 30, 40 K/min) at TGA are presented and discussed. Fuel properties with lignocelluloses content of the investigated feedstock are presented and discussed. Ambiguous results of the generalized master-plot method draw the idea of determining actual reaction models using the isoconversional methodology. Friedman method provided apparent activation energies as a root for further calculations being the 48.1–294.3 kJ/mol for WS, 21.0–361.9 kJ/mol for WW and 58.1–484.3 kJ/mol for SS. Isoconversional pre-exponential factors were determined using linear compensation effect and were 7.2·106–1.8·1021 1/min, 1.6·104–1.2·1025 1/min, and 1.5·109–3.2·1030 1/min for WS, WW, and SS respectively. Based on isoconversional parameters, actual profiles of reaction models were estimated using the t-Students distribution for 95% confidence intervals and verified in the modelling of pyrolysis conversion profiles. Isoconversional pyrolysis models resulted in fitting to experimental profiles with non-linear coefficients of determination equal to 0.9912, 0.9876, and 0.9406 for WW, WS, and SS respectively.

The article presents a review of works on mathematical modelling of biomass pyrolysis process. Models types, number of dimensions, captured phenomena, type and dimensions of the reactors and biomass particles as well as models validation methods were analysed. Particular attention was paid to descriptions of chemical reactions, which are the essence of biomass thermal decomposition simulation. The article briefly describes the most important issues related to biomass pyrolysis and provides a review of commonly used methods of modelling this process with emphasis on solutions "ready to employ" in CFD modelling. A summary of other review papers on this topic is also provided. The problem of mathematical modelling in the context of “model - an engineering tool” was also discussed. Mathematical model for an engineering applications must be prepared with consideration of necessary consensus between the calculations accuracy, calculation time, preparation efforts and analysis requirements. Therefore, in pyrolysis modelling context, the inclusion of chemical reactions and changes of heat transport conditions were considered as priority, while taking into account moisture evaporation and bed shrinkage should be conditioned by their actual contribution in the calculations accuracy and by their influence on the calculations time.

Biomass pyrolysis is a fundamental thermal conversion method that has both industrial and economic potential. A deep knowledge of the pyrolysis character can give dramatically rise to the general development of thermal conversion methods for the effective use of biomass fuel in the incoming future. In this work, kinetic parameters estimation methods and methodology for sewage sludge pyrolysis has been presented. Special emphasis was put into combined use of the latest isoconversional methodology and model-fitting kinetics. The kinetic parameters estimation was based on a series of experiments using thermogravimetric analysis carried out for heating rates 20, 30 and 40 K/min. Complimentary use of model-based and isoconversional approach along with statistical analysis of both methods results has been presented. The proposed methodology, based on Friedman isoconversional kinetic parameters, Eα 31.4–244.9 kJ/mol and Aα 1.17–14.4 log(1/s), as initial guess values for optimization resulted in 10 independent reactions kinetic model, evaluating sewage sludge pyrolysis with R2 > 0.999 with activation energies E∈ kJ/mol, pre-exponential factors A∈ log(1/s) and reaction orders n∈ . Isoconversional methodology resulted in excellent conversion rate and mass loss fit while the order-based kinetic model simultaneously gave insight into theoretical 10 elementary sludge decomposition rates.

In the present era of continually increasing energy demand, Europe faces many challenges, such as high and unstable energy prices, growing global energy demand, increasing threat of climate change, sluggish progress within energy efficiency and issues related to increasing demand for the use of renewable energy sources. It is desirable to seek opportunities to use energy consumed most reasonably, thus ensuring continuous improvement of energy efficiency in the industry. The scope of the research includes reviewing studies in this matter and analysing the most beneficial solutions for the plant. The work aims to assess possible undertakings to modernise the energy management of an industrial plant on the example of Bulten Poland S.A. rationally and profitably for the plant. The work contains an analysis of the profitability of the potentially most beneficial solutions in terms of improving the energy efficiency of the plant. Mentioned in the article solutions, aiming increasing energy efficiency, helped become the plant independent within heating up facilities. Total heat recovery potential in amount of 18 965 GJ is motivation for further activities. This is a great opportunity to reduce significantly carbon footprint (replacing lightening into LED technology reduced CO2 by 206.3 Mg/year) and be more competitive on the market by reducing costs of product.

In recent years solar-thermal methods of waste biomass conversion are promptly gaining on attention. For researchers working in areas that suffer from lack of natural solar power, the choice of proper solar simulator for the study is crucial. Solar simulator consist of artificial light source enclosed in proper housing with optical and cooling system, powered by dedicated power supply. Solar simulators are not only granting independence from external conditions, yet provide possibility of research expand due to tuneable output power and emissive spectrum. Over the years, solar simulators were powered by different types of lamps. Throughout the history, the solar simulators were used mainly in photovoltaic and space research, crystal growth industry, and the material testing. For mentioned purposes, the total thermal output power of simulator was playing secondary role in comparison to urgent need of spectral match, irradiance distribution and beam uniformity with terrestrial or extra-terrestrial sunlight. For thermal applications, solar simulators are facing the challenge of providing high output power, described by high radiant heat flux and high heat flux density over the specified target area. In presented paper the comparison of xenon arc, metal halide lams and tungsten halogen for thermal applications has been presented with emphasis on available thermal power, spectral match with natural sunlight and operational issues. The course of decision taken during the selection of artificial light source for construction of laboratory-scale solar pyrolytic reactor is proposed.

This paper deals with the Bayesian estimation of flow parameters in a porous material based on the measurements of local temperature at selected points inside the packed-bed. The unknown probability distribution function of estimated parameters was sampled using a Markov Chain Monte Carlo (MCMC) method. The MCMC method is efficient in sampling unknown distributions, but it is extremely time-consuming. The Proper Orthogonal Decomposition was used to construct off-line, low order approximation of the porous media flow problem. This model was further incorporated into the Metropolis-Hastings algorithm to retrieve the posterior distribution of the unknown parameters. This approach allowed us to decrease the computational time necessary to generate an ergodic Markov Chain. The efficiency of the proposed approach was tested on the simulated data generated with commercial CFD tools, and finally, it was applied to the real data acquired on the dedicated experimental stand.

Sewage sludge (SS) is a by-product of wastewater treatment plant (WWTP) operation. Due to fast rates of urbanization and industrialization, and rapid population growth, the world community faces a serious challenge associated with its disposal. There is an urgent need to explore low cost, energy efficient, and sustainable solutions for the treatment, management, and future utilization of SS. Thermal conversion of SS is considered the most promising alternative for sustainable SS management. Among three main thermochemical processes, it seems that gasification (GAS) of SS has the most advantages. The aim of this paper is a presentation of the gasification process as a sustainable method of SS management that takes into account the idea of a circular economy (CE). Gaseous fuel production, phosphorus recovery potential, and solid adsorbent production during the gasification process are analyzed and discussed. Result of this study shows that the lower heating value (LHV) of the gas from SS GAS process is up to 5 MJ/m3n and it can be effectively utilize in an internal combustion engines. The analysis proved that solid fraction after the SS GAS process can be treated as a valuable phosphorus source and perspective adsorbent materials. The amount of P2O5 in this material was equal to 22.06%. It is similar to natural phosphate rocks (28.05%). The maximum of the adsorption capacity of the phenol was comparable with commercial activated carbon (CAC): 42.22 mg/g for solid fraction after SS GAS and 49.72 mg/g for CAC. Graphical abstract.

The increasing worldwide demand for poultry, mainly chickens, has resulted in a growing generation of poultry derived wastes. Among many types of biomass, the animal waste, including poultry manure, can have a significant potential for application in the energy industry. In this work, the proposal of thermal utilization of the chicken manure was given. The laboratory scale research on co-gasification chicken manure with wood pellets has been carried out in a fixed bed gasifier of capacity 5 kg/h. The experiments were done for two types of fuel blends. In the first experiment stage wood pellets were mixed with a raw, pre-dried chicken manure. Another part of test concerned gasification of blends of pelletized chicken manure and wood pellets. The main goal of the experiments was to determine the influence of the addition of dried chicken manure to the wood pellet feedstock on the gasification process as well as on physicochemical properties of generated syngas. The results of the gasification tests confirm that co-gasification of the chicken manure with wood biomass can be a promising proposal for the utilization of a poultry derived wastes. Gasification of a chicken manure provides generation of combustible syngas with the lower heating value LHV equal to 2.0 MJ/m3 in case of a raw, pre-dried chicken manure and 2.7 MJ/m3 in case of chicken manure pellets. Increasing share of woody biomass in the feedstock significantly increases the calorific value of the syngas. Different physical properties of the feedstock components (fraction and ash content) require further research to define reactor suitable for co-gasification of analyzed fuel blends.

Two energy crops Miscanthus x giganteus and Sida hermaphrodita were used for a phytoremediation study on two different sites of soil contaminated with heavy metals in Poland and Germany. The energy crops were harvested and characterized with regards to fuel properties and thermal decomposition behaviour. Site influences on the data of proximate and ultimate analyses have been observed. Differences in the thermal decomposition are caused by the differences in pH value and heavy metal content of the soils.

The thermal decomposition kinetics of two energy crops Miscanthus x giganteus and Sida hermaphrodita biomass materials harvested from a phytoremediation study in Polish and Germany have been studied, assuming a three-pseudocomponent model. The kinetic parameters extracted from the study are realistic and within reasonable ranges. The activation energies are within 20 - 103.55 kJ/mol. The reaction orders are within 1.01-1.99. The result shows that the energy crops from the Polish site exhibited higher conversion rates than the samples from Germany. A negative effect of the ash content on the biomass reactivity is observed.

The article presents the methodology and results of a parametric analysis performed to investigate the effects of changes in the curvature of the solar concentrator mirror on its ability to focus the radiation. Working conditions of the concentrator, i. e. possible values of radiation intensity, were adopted according to irradiance typical for Poland, and, therefore, similar to the conditions in many European countries. The curvatures of examined mirrors were obtained by modification of a parabolic curve. The calculations were conducted for two cases: when the Sun radiation falls completely directly and when it's half diffuse. The 2-D simulations were conducted in ANSYS FLUENT 18.2 software. Discrete ordinates model was employed to simulate radiation phenomenon. Also, a sensitivity analysis was carried on discrete ordinates model parameters and density of the computational mesh. The results allow stating that some of the new curvatures provide only slightly worse focus than the classical parabolic shape, but also show greater insensitivity to the increasing share of diffusive part of radiation. The presented model is a quick and proven tool for testing new curvatures of solar concentrator mirrors.

The paper presents a two-dimensional computational fluid dynamics (CFD) model of lab-scale fixed-bed pyrolytic reactor. The goal of the work was to verify assumptions regarding construction and operating parameters of the pyrolytic reactor and examining heat transfer conditions and the final temperature distribution in the system taking into account the endothermic pyrolysis reactions occurrence. The impact of the most important numerical parameters on simulation results was also investigated. Model was prepared in ansys fluent 18.2 software. The studies have shown large temperature gradients both in the biomass deposit and at the reactor walls. The analysis has confirmed the validity of the proposed reactor construction concept and allowed to specify the range of thermal power value necessary for obtaining the pyrolysis process in a system with given properties and dimensions. Increasing the heat flux supplying the reactor from 160 to 480 W caused acceleration and intensification of biomass thermal decomposition, while the average final bed temperature after 10 min of heating in each case was reaching similar level. Low thermal conductivity of the bed and strong heat absorption due to pyrolysis suppress heat transfer through the bed, which causes significant temperature differences between the warmest and coldest regions of the bed. However, temperature unevenness and hence the unevenness of the pyrolysis process can provide favorable conditions for measuring the gas composition leaving the reactor due to the relatively balanced time stream of pyrolysis gases.

In this study, HTC impact on the waste straw fuel properties and waste straw hydrochars combustion kinetics have been presented. HTC experiments were carried out at Parr 4650 250 ml batch reactor, at temperatures of 225, 250, and 275 °C. Each temperature was investigated at 4 residence times: 10, 20, 30, and 40 min. Denoted hydrochars yields were more influenced by temperature than residence time, with different decomposition patterns observed at 275 °C compared to 225 and 250 °C, with final solid yields of 42.0%, 66.9%, and 65.3% at 40 min residence times respectively. The study of the transient HTC period resulted in the determination of the exothermal WS activity with the heat release of the 254.9 ± 48.8 kJ/kg of biomass. LHV values of the obtained hydrochars were 18.7–20.2 MJ/kg, 19.9–22.2 MJ/kg, and 23.1–26.2 MJ/kg for HTC temperatures of 225, 250, and 275 °C respectively. TGA analysis of the hydrochar combustion highlighted significant changes in the kinetic interpretation of the combustion profiles throughout investigated temperature ranges. The influence of residence time was only significant in the case of the 275 °C HTC samples, where a major shift of the combustion reactivity towards higher-temperature char oxidation was denoted. Hydrochars combustion kinetics were modeled with the implementation of Fraser-Suzuki deconvolution, and model-fitting of nth-order Arrhenius equation, with R2 values within 0.98–0.99.

Increasing problems associated with sewage sludge disposal are observed nowadays. As the thermal conversion of sewage sludge (combustion, co-combustion, gasification and pyrolysis) appears to be the most promising alternative for its management, the solid residues left after gasification were examined. The present study evaluates the potential of this waste as an alternative phosphorus source in the context of phosphorus recovery. The obtained solid gasification residues were characterised (chemical and phase composition, thermal properties, surface properties and technological parameters used for phosphorus raw materials) and compared to commercial phosphate raw materials. It was revealed that gasification residue is a valuable source of phosphorus and microelements, comparable to sewage sludge ash (SSA) considered nowadays as secondary phosphorus raw materials. Chemical properties as well as technological parameters characteristic for natural phosphate ores are different. Solid gasification residue was leached with mineral acids (phosphoric and nitric) according to the patented method of phosphorus recovery - PolFerAsh, developed by Cracow University of Technology. It was revealed that phosphorus can be selectively leached from solid gasification residue with high efficiency (73-82%); moreover, most of the iron and heavy metals stay in the solid phase due to the low concentration of acids and proper solid to liquid phase ratio. The obtained leachates are valuable products that can be considered for the production of fertilisers. Combining the gasification process with nutrient recovery provides the opportunity for more environmentally efficient technologies driven by sustainable development rules.

The use of biomass fuels is continually investigated, and the industry application possibilities are widely recognized. In the paper, an experimental investigation of gasification in a fixed-bed atmospheric reactor of selected energy crops is presented. These crops belong to the class of phytoremediation plants, and their potential to combine agroenergetics and active environment improvements is studied. The composition and characteristics of the obtained gas allow its use in an internal combustion engine. Composition of gas obtained from Sida hermaphrodita during the experimental study was used for thermodynamic and economic analysis of a CHP system with a gas engine. The system quality indices were calculated. For the economic analysis, the net present value method was adopted. The break-even price of electricity ( c el b - e ) was calculated. The paper includes a sensitivity analysis of change in the heat and biomass price. The power of the analyzed units was in the range of 1–5 MW in biomass chemical energy. The c el b - e ranges from 90.05 €/MWh (1 MW of supplied chemical energy in biomass) to 48.41 €/MWh (5 MW of supplied chemical energy in biomass).

Crop growth and development can be influenced by a range of parameters, soil health, cultivation and nutrient status all play a major role. Nutrient status of plants can be enhanced both through chemical fertiliser additions (e.g. N, P, K supplementation) or microbial fixation and mobilisation of naturally occurring nutrients. With current EU priorities discouraging the production of biomass on high quality soils there is a need to investigate the potential of more marginal soils to produce these feedstocks and the impacts of soil amendments on crop yields within them. This study investigated the potential for Miscanthus x giganteus to be grown in trace element (TE)-contaminated soils, ideally offering a mechanism to (phyto)manage these contaminated lands. Comprehensive surveys are needed to understand plant-soil interactions under these conditions. Here we studied the impacts of two fertiliser treatments on soil physico-chemical properties under Miscanthus x giganteus cultivated on Pb, Cd and Zn contaminated arable land. Results covered a range of parameters, including soil rhizosphere activity, arbuscular mycorrhization (AM), as well as plant physiological parameters associated with photosynthesis, TE leaf concentrations and growth performance. Fertilization increased growth and gas exchange capacity, enhanced rhizosphere microbial activity and increased Zn, Mg and N leaf concentration. Fertilization reduced root colonisation by AMF and caused higher chlorophyll concentration in plant leaves. Microbial inoculation seems to be a promising alternative for chemical fertilizers, especially due to an insignificant influence on the mobility of toxic trace elements (particularly Cd and Zn).

Thermal Analysis determines a set of methods for the study of the selected physical properties of the substance under the influence of temperature or atmosphere. Thermogravimetric (TG) analysis is very useful for studying the kinetics of gasification processes. However, by itself TG does not allow the direct identification of the gases released from the sample during the thermal treatment. For this purpose, coupling TG to a spectroscopic interrogation method, such as Fourier-Transform-Infrared (FT-IR) spectroscopy, is an excellent solution. The objective of this paper is to ascertain the usefulness and limitations of TG-FTIR technique in the study of biomass gasification and to determine gasification product evolution patterns and yields for heavy metal contaminated (HMC) samples of Miscanthu s x giganteus , Sida hermaphrodita , Spartina pectinata and Panicum virgatum . In experiments reported in this paper, biomass samples were heated at 10° C min −1 in a nitrogen environment and the volatile products were swept immediately into a cooler gas cell, which minimized secondary reactions. Process products were quantitatively analysed by gas-phase Fourier transform infrared (FT-IR) spectroscopy. This gas analysis combined with weight loss measurements of the heated material ensured generally good mass-balance closure. The paper discusses the techniques employed to identify the evolved products and presents the product evolution patterns and yields.

A fixed-bed based solar pyrolysis of three waste biomass types: waste wood (WW), waste straw (WS), and sewage sludge (SS) was performed with emphasis on heating behaviour description, products yields, and quality. Laboratory solar pyrolysis reactor setup consists of a copper block indirectly heated by research-grade 1.6 kW xenon lamp radiation. Actual heating rates observed for 90, 95 and 100% xenon lamp power are 4.51, 5.32, and 5.49 K/min for WS; 5.10, 5.19, and 5.37 K/min for WW; and 3.95, 4.48, and 5.25 K/min for SS, respectively. Solar pyrolysis product yields (bio-oil, gas, char) were 51.68, 9.53, and 38.79 wt% for SS, 69.23, 9.18, and 21.59 wt% for WW, 62.30, 10.64, and 27.06 wt% for WS, denoted for the specific heating rates in ascending order. The highest quality bio-oil was obtained from WW pyrolysis with the lowest oxygen to carbon fraction and higher heating value (HHV) of 21.99 MJ/kg. Obtained chars, especially after solar pyrolysis of lignocellulosic biomass, presented HHV of 27.09 MJ/kg and 22.02 MJ/kg for WW and WS respectively, showed significant potential for renewable solid fuel. The increase of the lamp power, and long process time, caused degradation of porous structures within the biomass, where among the samples the highest specific surface area (BET) was denoted for WW samples at 5.2 K/min with 145.09 m2/g. Correlation between model-free kinetic predictions and gaseous species evolution was found, proving the value of apparent isoconversional activation energy profiles in describing actual solar pyrolysis gas compound formation at the laboratory scale.

The paper presents the results of basic physico-chemical properties of solid (ash) and liquid (tar) waste products of the gasification process of the heavy metal contaminated energy crops. The gasification process has carried out in a laboratory fixed bed reactor. Three types of energy crops: Miscanthus x giganteus, Sida hermaphrodita and Spartina Pectinata were used. The experimental plots were established on heavy metal contaminated arable land located in Bytom (southern part of Poland, Silesian Voivodship).

The aim of this study was to determine the effect of powdered activated carbon on fouling intensity of capillary membranes working in the submerged membrane bioreactor during the treatment of synthetic municipal wastewater loaded with organic compounds. The research were carried out in a membrane bioreactor including a capillary ultrafiltration module made of polyethersulfone. The feed used in the presented study was synthetic municipal wastewater which was prepared in order to include high organic content. Moreover, the volumetric flux of the treated wastewater and the percentage of reversible and irreversible fouling were determined. It was found that activated carbon addition to a membrane bioreactor (MBR) treating wastewater reduced irreversible fouling. The volumetric flux of the treated wastewater for PAC-assisted MBRs was higher by approximately 40% as compared to the volumetric flux of the treated wastewater without any sorbents.

Despite the burgeoning literature on Russia’s renewed power politics, little attention has been paid to the fact that US reactions towards Russia’s military interventions were all but coherent. The USA has chosen weak measures in Georgia in 2008 (shaming) compared to its assertive response in Ukraine in 2014 (sanctions, hard deterrence). This article assesses the explanatory power of neorealist, liberal and constructivist theories for the variation in US reactions towards Russian interventions in Georgia and Ukraine. Our argument is that the constructivist perspective explains the cases best as it highlights the power and communality of normative assessments. The Ukraine crisis was perceived by the USA as a violation of core international norms, especially the non-use of force and the principle of territorial integrity. Relevant international norm carriers shared this assessment of the conflict. In contrast, the perception of the Georgian war centred on the issue of democracy promotion. While demo...

Biomass is one of the major sources of energy that is estimated to contribute between 10% and 14% of the world’s energy supply. Over the past several years, many societies have established policy targets to increase their production of renewable energy from biomass. The thermo-chemical utilization of biomass includes 4 technologies: the most popular combustion and co-firing, and unconventional: pyrolysis and gasification. Gasification is considered to be the perspective technology because has many advantages in comparison to traditional process of combustion: (1) limited emission of the SO2, NOx, oxides of the heavy metals and no risk of the dioxins and furans emission due to reducing atmosphere in the gasification reactor, (2) volume of the gasification gas is smaller in comparison to flue gases from combustion due to the reducing atmosphere, (3) gasification process produce gas which is potential gaseous fuel in power engineering (engines, gas turbines and boilers) and chemistry. Unfortunately, composition of the gasification gas is always described as a variable. Moreover, it depends on the conditions of the process and quality of the base fuel. For this reason, the use of gasification gas can’t be very easy. For this reason, the knowledge of the basic properties of the gas is very important. Laminar burning velocity is assumed as an important quantity for in the process of the design equipment for the gas utilization. The numerical and experimental results of the laminar burning velocity of sewage sludge gasification gases were presented. Experimental Bunsen burner method was used. Cosilab 3© software for numerical analysis was used. GRI-Mech 3.0 mechanism of gas oxidation was implemented. As a result of the work, the set of the parameters where the sewage sludge gasification gas combustion process is stable with effective heat release, were presented.

Thermal conversion (combustion, co-combustion, gasification and pyrolysis) appears to be the most promising alternative for sewage sludge management in the future. Nevertheless, safe and ecological usage of sewage sludge as a fuel requires information about their contamination. The aim of this paper is to present the photoacoustic spectroscopy (PAS) as a good method for contamination assessments of dried sewage sludge. Two types of granular sewage sludge: Sewage sludge 1 (SS1) taken from Polish wastewater treatment plant operating in the mechanical-biological system and sewage sludge 2 (SS2) taken from mechanical-biological-chemical wastewater treatment plant with phosphorus precipitation were analysed. The spectrophotometer FTIR Nicolet 6700 equipped with photoacoustic cell (Model 300, MTEC, USA) was used. The comparison with the most popular analytical methods (GC-MS) was also done. The results of PAS studies confirm the difference between the SS1 and SS2 which is in agreement with the GC-MS analysis. Higher absorbance was observed at each wavelength characteristics for the oscillator of chemical moieties for the SS1 with respect to the SS2.

Under the Kyoto protocol, many countries and international communities in general have ambitious targets for the reduction of greenhouse gas (mainly CO2) emissions and global warming. Globally, industrial primary energy use and conversion for electricity and heat are responsible for 46% of greenhouse gas emissions. In Europe, the introduction of the Energy Efficiency Directive in 2012 has led to an increase in the number of Energy Efficiency Obligations - EEOs (also known as White Certificates or energy efficiency resource standards across Europe). 12 EU Member States (Austria, Bulgaria, Denmark, France, Ireland, Italy, Luxembourg, Malta, Poland, Slovenia, Spain, UK) have active EEOs with another four due to start shortly (Croatia, Greece, Latvia and the Netherlands) considering their introduction. Due to this fact, in Poland, pro-efficiency investments are gaining in popularity. Industrial plant Bulten Poland S.A. dealing the production of fasteners for the automotive industry has a heat treatment department, which is the most energy-intensive part in the manufacture of screw products. It results in significant carbon footprint (total CO2 emission from gas usage at the heat treatment department is at the level of 3,885 Mg/year). For this reason, to increase energy efficiency and simultaneously reduce CO2 emission, waste heat recovery has been introduced on the Aichelin hardening line. The heat recovery has been located on the oil bath and at the exhaust pipe from the gas burners. The recovered waste heat is captured by the buffer in the form of a water tank. The water is injected into the central heating system and used in the heating season to maintain appropriate temperatures in the halls and offices. Furthermore, the possibility of installing cogeneration unit has been investigated as a way to minimize carbon footprint of the production. The work presents an analysis of improving the energy efficiency and reduce of CO2 emission by implementing solutions such as: heat recovery and use a cogeneration unit. Estimated CO2 savings are at the level of 1,350 Mg/year which gives about 35% of total emission.

The cultivation of energy crops on heavy metals contaminated (HMC) areas offer opportunities, which combine site remediation with energy recovery. Numerous tests have been conducted using phytoremediation in HMC soils with energy crop species. Sida hermaphrodita L. Rusby, has shown potential as an energy crop useful in the phytoextraction of HMs. The aim of the study was to investigate the efficiency of using S. hermaphrodita in energy crop production in HMs contaminated sites. The study investigated the impact of different fertiliser treatments on the composition of elements in cultivated biomass on HMC arable land and sewage sludge dewatering sites to determine its suitability for energy production in gasification processing. It was found that S. hermaphrodita is a species accumulating HMs mainly due to their bioavailability in soil (Cd r = 0.877, Zn r = 0.876). Calculated Cd and Zn bioaccumulation factors for plants cultivated on HMC arable land were 12-fold and 18-fold higher respectively, when compared to a sewage sludge dewatering site. Lower heating value of biomass was higher by about 7% for biomass cultivated on HMC arable land. Despite the presence of HMs in ash after the gasification process, some of it could be used as fertilizer, especially on heavy metal contaminated sites.

Paper present the experimental and numerical analysis of biomass photopyrolysis process. The experimental tests is performed on the solar pyrolysis installation, designed in Institute of Thermal Technology, Gliwice. It consist of the copper reactor powered by artificial light simulating sun. The paper shows the result of the solar pyrolysis of wood. The yield of the main fraction as a function of the process temperature is presented. Additionally the gas composition is determined. The numerical model is prepared in the Ansys Fluent 18.2 software, which allow at the same time for capturing geometry of the real system and easy change of input data. The results indicate that both the product yields (liquid, solid and gaseous) and gas components shares are strongly influenced by pyrolysis parameters and feedstock composition.

An increasing number of problems associated with sewage sludge disposal are being observed nowadays. Thermal conversion of sewage sludge (combustion, cocombustion, gasification and pyrolysis) appears to be the most promising alternative for its management. Of these methods, gasification is the most advantageous. This chapter presents a multicriteria investigation of sewage sludge gasification in a fixed-bed gasifier. The operating parameters of gasification vary over a wide range. Parameters such as air ratio λ = 0.12–0.27, gasification agent preheating t = 50–250°C, and gasification agent composition (zO2 = 0.21 and zO2 = 0.25) are found to influence the lower heating value (LHV) and composition of the gasification gas and temperature distribution in the reactor. A profile of the contaminants existing in sewage sludge and by-products (tar and ash) is also presented. For the sample analysis, standard techniques (gas chromatography and absorption spectroscopy) and other indirect analytical methods (photoacoustic spectroscopy and ecotoxicological analysis) are used. The management and purification methods of gasification by-products are also discussed.