Karol Postawa

The paper deals with thermodynamic analysis of CH₄ reforming with different oxidants (CO₂, H₂O, and O₂) in DRM and TRM processes. Both processes producing syngas use simultaneously two components of greenhouse gases as feedstock: CO₂ and CH₄. Statistical methods (Response Surface Methodology, Ridge Analysis) were used to analyze the effects of temperature, pressure, and molar ratio of oxidants to methane on feedstock conversion, yield and selectivity of products, H₂ and CO, and the H₂/CO ratio characterizing the suitability of syngas for various syntheses. The problem of the propensity of carbon deposition in the Dry Reforming of Methane (DRM) process through the selection of operational process conditions was minimized, and in the case of the TRM process was reduced completely. The Dry Reforming of Methane (DRM) process, which is a source of synthesis gas for the subsequent synthesis of long-chain hydrocarbons (H₂/CO = 1), is recommended to be carried out at high temperature (1273 K), low pressure (1 atm) with a molar ratio of CO₂/CH₄ in the feedstock of about 1. Increasing the proportion of CO₂ in the feedstock reduces the cooking of the catalyst but at the same time reduces the hydrogen yield. Additional oxidants (O₂, H₂O) introduced into the system define the TRM process and enable the production of synthesis gas with a composition suitable for methanol production (H₂/CO = 2). A positive effect on increasing the H/CO ratio is the addition of H₂O, which intensifies the WGS reaction in the system. Both oxidants (O₂, H₂O) protect to some extent against catalyst cooking, but at the same time reduce hydrogen yield and CO₂ conversion, as they are more reactive in the reaction with CH₄.

In the context of climate policy, measures are being taken around the world to reduce pollution. These have been intensified in the areas of transport, industry, and energy, with the goal of zero emissions. The role of the biogas plant in energy transition and as a waste treatment plant for disposal is very important. This article describes research on a dynamic anaerobic digestion (AD) process plant. The subject of this study was leather shavings, which is a problematic waste. The research presented here is intended to demonstrate the decomposition of the flesh in the process, to confirm its biogas yield, and to evaluate the biological and technical parameters of the process. High biochemical stability was achieved for each of the tests evaluated, and no specific technical requirements were demonstrated. The only technical aspect to be addressed during operation was sedimentation, which can be solved by preparing the mixture earlier or by changing the mixing method. This made it reasonable to investigate the material further in the context of an industrial project. The characteristics of protein degradation in the AD process resulted in a high methane content in the biogas, above 65%. It was also observed that the long conditioning time of biogas in the gas cushion favourably affected the proportion of methane in biogas. Analytical results confirmed 77.5% methane content, which was a very good result. This paper presents the results of a surprising effect of chromium, primarily Cr (III), on the performance of anaerobic digestion.

Unsustainable pig breeding is a great threat to the environment. Ammonia is one of the main pollutants emitted in piggery vent air. This work is a comparative survey that presents the findings on the effectiveness of ammonia adsorption from air using various activated carbons (ACs). Detailed consideration is given to the effects of (i) type of raw material (wood char, wood pellet, and commercial lignite-based char), (ii) preparation method (CO₂, steam, and KOH activation), and (iii) activation conditions (temperature and KOH/char ratio), on the porous structure of ACs and their ammonia sorption capacity and reversibility. Response surface methodology and genetic algorithm were used to find optimum KOH activation conditions. Economic analyses of AC production were performed using process modeling in Aspen software. It was found that ACs obtained from wood char in KOH activation show a maximum ammonia capacity of 397 g/kg, which is at least 2.5-fold higher than that reached on ACs from physical activation. A lower activation temperature (3) were preferred for effective adsorption, regardless of the type of feedstock. High sorption reversibility was achieved (87–96%). This makes the obtained sorbents promising sorbents for ammonia removal from piggery vent air with potential subsequent application as nitrogen-enriched biochar for crop fertilization. Thus, it facilitates sustainable pig breeding.

Solar energy is a promising and efficient source of electricity in countries with stable and high sunshine duration. However, in less favorable conditions, for example in continental, temperate climates, the process requires optimization to be cost-effective. This cannot be done without the support of appropriate mathematical and numerical methods. This work presents a procedure for the construction and optimization of an artificial neural network (ANN), along with an example of its practical application under the conditions mentioned above. In the study, data gathered from a photovoltaic system in 457 consecutive days were utilized. The data includes measurements of generated power, as well as meteorological records. The cascade-forward ANN was trained with a resilient backpropagation procedure and sum squared error as a performance function. The final ANN has two hidden layers with nine and six nodes. This resulted in a relative error of 10.78% and R² of 0.92–0.97 depending on the data sample. The case study was used to present an example of the potential application of the tool. This approach proved the real benefits of the optimization of energy consumption.