Commonly based on the liquid diffusion theory, drying theoretical studies in porous materials has been directed to plate, cylinder, and sphere, and few works are applied to non-conventional geometries. In this sense, this work aims to study, theoretically, the drying of solids with oblate spheroidal geometry based on the thermodynamics of irreversible processes. Mathematical modeling is proposed to describe, simultaneously, the heat and mass transfer (liquid and vapor) during the drying process, considering the variability of the transport coefficients and the convective boundary conditions on the solid surface, with particular reference to convective drying of lentil grains at low temperature and moderate air relative humidity. All the governing equations were written in the oblate spheroidal coordinates system and solved numerically using the finite-volume technique and the iterative Gauss−Seidel method. Numerical results of moisture content, temperature, liquid, vapor, and heat flux... [more]

Conventional energy sources often do not fully satisfy the needs of a modern economy, especially given the climate changes associated with them. These issues should be addressed by diversification of energy generation, including the development of renewable energy sources (RES). Solid biomass will play a major part in the process in Poland. The function of rural areas, along with a well-developed agricultural and forest economy sector, will be a key aspect in this as these areas are suitable for solid biomass acquisition in various ways. This study aimed to determine the solid biomass energy potential in the commune of Goworowo to illustrate the potential in the smallest administrative units of Poland. This research determined the environmental and natural conditions in the commune, which helped to identify the crucial usable solid biomass resources. The total energy potential of solid biomass resources in the commune of Goworowo amounted to 97,672 GJ y−1. The highest potential was acc... [more]

The negative effect of liquid and gaseous fuel combustion is toxic gases (i.e., carbon and nitrogen oxides NOx) and particulate matter (PM) formation. The content of harmful and toxic components of exhaust gases is strongly dependent on the quality and type of burnt fuel. Experimental research is required to verify the use of current technical and technological solutions for the production of electricity on farms, using various types of conventional fuels and biofuels. The aim of the current research was to comprehensively verify the use of commonly available fuels and biofuels without adapting the internal combustion engine. Gaseous fuels—propane-butane mixture (LPG), compressed natural gas (CNG) and biogas (BG)—were added to liquid fuels—methyl esters of higher fatty acids (RME) and diesel fuel (DF)—in six different power configurations to evaluate the effect on the emission of toxic gases: carbon monoxide (CO), nitric oxide (NO), nitric dioxide (NO2) and particulate matter (PM), and... [more]

Ensuring adequate profitability of production, which can be ensured by optimal investments, can encourage farmers to be more caring about sustainable development. Several existing studies indicate that technical efficiency in agriculture varies regionally. Investments comprise a basic way to increase efficiency and thus reduce polarisation between regions. However, contrary to established assumptions, not every investment leads to increased efficiency, which entails a phenomenon of overinvestment. Investments should, by definition, be positively correlated with efficiency. However, existing studies indicate the existence of a significant problem of overinvestment, where increased efficiency may not occur. While for about 40% of farms in Poland the scale of investments can be assessed as optimal, more than quarter of farms exhibited absolute overinvestment and nearly one in five farms is underinvested. In response to this problem, this study aimed to identify regional differences in Pol... [more]

Energy is the prerequisite for social and economic development of a community and country. In Japan, national government is promoting small hydropower (SHP) through a renewable energy policy by providing a high FIT price of 34 yen (≒0.32 US$/kWh) on energy generated from an SHP of less than 200 kW. Until now, the energy generation was controlled by national government agencies, but now independent power generation businesses are growing at the local community level in rural Japan. For the future growth of SHP, it is necessary to make electricity generation at the local community level. Therefore, these local communities will install and manage their renewable electricity by themselves. It will help to make the community self-sustainable and independent from the national government, and at the same time, it will also lead them to achieve the Sustainable Developments Goals (SDGs) target from community-based action. This paper aimed to discuss an SHP development business model in which lo... [more]

The objective of this paper is to enhance the dominant research perspective of innovations in the food market (power or supply chain centric) with an interactive/network approach. Many scholars identify the development challenges facing the food sector, including economic factors, changes in lifestyle, climate change, changes to the food consumption mix, shrinkage of Earth’s resources and interactions between food production and the environment, in the context of sustainable development. A new approach to innovations in the food market may shift it towards a more sustainable path of development. Based on a literature review, we present the specific conditions for innovation in the food market and discuss previous research as being focused on the power of operators and flows in supply chains. Methodologically, this paper puts these considerations in the context of interaction and business networks. We note that the concept of power and dependence can be embedded with the concept of inte... [more]

The European Green Deal aims to make Europe the world’s first climate-neutral continent by 2050 by shifting to a clean circular economy, combating biodiversity loss and reducing pollution levels. In Poland, whose economy invariably remains one of the most dependent on coal consumption in Europe, institutional responses to the above EU objectives have taken the shape of energy cooperatives aimed at filling the gaps in the development of the civic dimension of energy on a local scale and the use of potential renewable energy sources in rural areas, including in relation to the agricultural sector. This article is a continuation of the authors’ previous research work, which has so far focused on the analysis of the development of profitability of Polish institutions that fit into the European idea of a “local energy community”, which includes energy cooperatives. In this research paper, they present the results of subsequent research work and analyses performed on the basis of it which, o... [more]

This article introduces a BackfillCAD model that relates to the determination of the backfilling time. The relationship of the individual model modules using a flow chart are characterized and presented. The main aim of the research was to determine the time of backfilling for the prospective deposits of zinc and lead ores in the Olkusz region in Poland. In the first stage of the research, laboratory tests were carried out on the backfilling mixture consisting of sand and water in a 1:1 volume ratio. In the laboratory tests, the content of grains below 0.1 mm, the washability, water permeability, and compressibility of the backfilling mixture were determined. After the standard requirements were met by the backfilling mixture, the arrangement of one-way and bidirectional strip excavations was designed. In the next stages, by means of computer aided-design MineScape software, maximum thicknesses of the ore-bearing dolomite layer (T21_VI) for four geological cross-sections were determine... [more]

The aim of this article is to indicate the rationale for the development of the bioeconomy in selected EU countries depending on their overall level of economic development. The research was based on four highly developed countries, i.e., Germany, France, Finland and Denmark, and four medium-developed countries, i.e., Poland, Hungary, Czech Republic, and Slovakia for the period 2001−2018. Renewable energy consumption, biomass and agricultural production were analysed as determinants of the bioeconomy development. The question was also answered whether differences in terms of measures determining the level of bioeconomy development between countries with different levels of economic development during the studied period are decreasing or increasing, using sigma (σ)-convergence coefficients. It is shown that the development of the bioeconomy of the studied countries is related to their level of economic development. In the middle economically developed countries, real opportunities for t... [more]

The proposed study aims to segment consumers based on a sustainable approach to the consumption of food. The shift in consumers’ attitudes towards more balanced food consumption can be one of the sustainability drivers for entire food chains and may result in more sustained energy usage in the whole food chain and implementation of farm to fork strategy to the practice. We considered consumers’ attitudes as a multidimensional construct. Under this assumption, we asked respondents a series of questions related to the cognitive, behavioral, and affective components of an attitude. Data were collected from a market survey run among 433 consumers. We identified three consumer segments. The “Doers” segment exhibits sustainable behavior to a greater extent than the others. At the same time, they have less knowledge about the concept of food sustainability while the affective dimension was developed on an average level. The “Conscious” segment had well-developed cognitive and affective dimens... [more]

The growing energy needs of agriculture, the need to reduce the burning of fossil fuels, and, on the other hand, the increasing technical efficiency are contributing to the wider use of solar energy technology in agriculture. The aim of the article is to identify factors determining farmers’ investments in solar photovoltaic and solar thermal installations for electricity and heat production, to establish the proportion between the consumption of such energy for the needs of the farmer’s family and for the needs of the farm, and to identify the drivers of solar energy use in agricultural production. Empirical materials were collected through surveys of farmers conducted at the end of 2020 in south-eastern Poland, in the Podkarpackie region. It is a region characterized by significant land fragmentation. Producing energy from renewable sources can be an opportunity for farmers not only to reduce household expenses, but also to increase agricultural income. As a result, it can be a drive... [more]

The study aimed to assess the most efficient solution of raw material management in selected biogas plants into the concept of circular economy and evaluate the most efficient solution of raw material management in selected biogas plants due to the quality and quantity of the feed and the final product obtained, which is biogas, as well at the closed circulation (circular economy). The study evaluated two agricultural biogas plants on a real scale and one at the sewage treatment plant (in real scale) in northeastern Poland. A year-long study showed that in technical terms, the best work efficiency is achieved by agricultural biogas plants processing: silage, manure, apple pomace, potato pulp (biogas plant No. 1), followed by biogas plant No. 3 processing chicken manure, decoction, cattle manure, poultry slaughterhouse waste (sewage sludge, flotate, feathers), and finally, the lowest efficiency biogas plant was No. 2, the sewage treatment plant, which stabilized sewage sludge in the met... [more]

China is a large agricultural country with a high level of agricultural carbon emissions. Whether market prices can be used in agricultural production as a means of agricultural carbon emissions reduction is of great significance to improve the allocation of agricultural production factors and expand large-scale production. This paper applies an autoregressive distributed lag−pooled mean group(ARDL−PMG) model to evaluate the relationship between agricultural production factor prices, food consumption prices, and agricultural carbon emissions, using Chinese provincial panel data from 1994 to 2018. The results show that agricultural carbon emissions and agricultural production factor prices show environmental Kuznets curve (EKC) characteristics; agricultural carbon emissions and food prices show a U-shaped curve; and agricultural production factors are positively correlated with food price in both directions in the long-term. The results of Granger causality tests show that price is the... [more]

Sludge incineration is a sludge resource management and disposal method that can greatly decrease the volume of sludge, reduce the degree of harm and realize the recovery of sludge heat energy. Most of the research on sludge incineration focuses on the combustion process and gas emissions, but there are relatively few studies on the sludge fuel molding and drying process before sludge incineration. Besides, independent incineration of sludge has high energy consumption. This paper proposes a pre-incineration treatment method in which sludge and corn stover are mixed to make fuel pellets and then dried. Specifically, the influence of molding pressure, raw material ratio and raw material particle size on the physical properties of the fuel, and the related mechanism, were studied. The density of fuel particles is mainly affected by the forming pressure, and the impermeability is mainly determined by the proportion of sludge in the raw material. The order of the variables based on their e... [more]

Non-conventional extraction of bioactive metabolites could provide sustainable alternative techniques to preserve the potency of antioxidants and antiviral compounds extracted from macro-algae. In this paper, we first reviewed the antioxidant and antiviral potential of the active metabolites that exist in the three known macro-algae classes; Phaeophyceae, Rhodophyceae, and Chlorophyceae, and a comparison between their activities is discussed. Secondly, a review of conventional and non-conventional extraction methods is undertaken. The review then focused on identifying the optimal extraction method of sulphated polysaccharide from macro-algae that exhibits both antiviral and antioxidant activity. The review finds that species belonging to the Phaeophyceae and Rhodophceae classes are primarily potent against herpes simplex virus, followed by human immunodeficiency virus and influenza virus. At the same time, species belonging to Chlorophyceae class are recorded by most of the scholars t... [more]

The aim of this study was the investigation of the effect of growth conditions of energy willow (Salix viminalis L.) on its physical and chemical parameters towards lignocellulosic biofuels. This work is linked to the global trend of replacing fossil fuels (coal, oil, natural gas) with energy and renewable fuels. This energy transition is dictated by the reduction of the human-induced greenhouse effect (to the greatest extent by industrial development). Changing from traditional to renewable energy sources results in industry becoming less dependent on fuels whose sources are beginning to run out, and in energy processing being broken down into smaller sectors with greater flexibility to change and less susceptibility to failure. The use of lignocellulosic raw materials such as wood, straw, food industry waste, wood, and post-consumer products such as old furniture for energy purposes allows the use of substances which bind the greenhouse gas carbon dioxide in their cellular structure... [more]

Abundant biomass is a potential energy source. However, it possesses several challenges when considered for energy applications. Torrefaction, a thermal pretreatment process can improve the properties of biomass as energy source. This study focused on comparing effect of torrefaction operating parameters on agricultural and wood wastes properties as fuel. The physiochemical properties, composition, moisture-biomass interaction and ash melting behavior were determined. The result show that higher torrefaction temperature and longer residence time increased lignin content, reduced hemicellulose and cellulose content. The moisture uptake of torrefied biomass was reduced in the range 2.47−9.94% compared with raw biomass depending on torrefaction temperature that indicate torrefied biomass was more hydrophobic than raw biomass. The moisture adsorption isotherm curve shows type II isotherm based on the Brunauer-Emmett-Teller’s (BET) classification and was best described by the Oswin model. I... [more]

The aim of the article is to identify and assess the relationship between the investment attractiveness of regions for agricultural enterprises and the energy factor. Classical theories of the location of agriculture emphasise the importance of the market factor. The energy factor has so far been ignored, despite the global trend related to the increasing importance of production scales and rising energy consumption in agriculture. There are also no methodological proposals that allow a comprehensive assessment of the investment attractiveness of regions for agricultural enterprises, taking into account the leading location factors. The article presents the author’s methodological model based on the weight-correlation method of valorisation of investment attractiveness of regions for economic entities that invest in agricultural production. It contains a sub-aggregate describing the energy factor. This proposal is a contribution to the theory of the location of agriculture in the field... [more]

In many circles, including in Poland, lignite is still viewed as a cheap source of energy, which is only possible if the external costs associated with mining and burning coal are not taken into account. In Poland, this is reflected in plans to open new Złoczew opencast lignite mines. In previous studies, the analysis of external costs has focused on the external costs of coal combustion and related pollutant emissions. This paper focuses on the extraction phase. The aim of the work here described was to estimate the external costs that agriculture may incur due to the formation of a depression funnel for the projected lignite mine in the Złoczew deposit. This paper discusses factors causing uncertainty in calculated estimates of external costs in agriculture, and characterizes the Bełchatów and Złoczew opencast mines. In the paper, a methodology for calculating external costs in livestock production is then proposed. In the next part of the study, the decrease in cereal and potato yie... [more]

Ionisation can occur in the soil when high impulse currents are subjected to grounding systems. This occurrence is generated by a difference in the dielectric strength value between the soil and air voids. Several published works investigating the ionisation process in soil have seen that the degree of ionisation is dependent on several factors, among them soil resistivity, ground electrode size and impulse polarity. The effects on soil resistivity, such as the moisture content in soil, soil grain size, type of soil and its temperature, have been studied; however, the effect of the size of air voids in soil has not been extensively presented. This study considered four rod electrodes—a conventional rod electrode, conventional electrode with porous concrete (PC), conventional electrode with concrete mixed with a foaming agent (FC) and conventional electrode with concrete (NC)—to provide variations in the size of air voids. Resistance values, RDC, were measured for all these electrodes,... [more]

Lignocellulosic biomass is one of the dominant renewable energy resources suited for the production of sustainable biofuels and other energy purposes. This study was focused on weed management strategies that can improve the establishment of six lignocellulosic crops. The studied crops included: giant miscanthus, switchgrass, giant reed, cardoon, sweet sorghum, and kenaf. Delayed planting, increased planting densities, and mulching techniques can suppress weeds in giant miscanthus. Weed competition is detrimental for switchgrass establishment. Seedbed preparation and cultivar selection can determine its ability to compete with weeds. Giant reed is unlikely to get outcompeted by weeds, and any weed control operation is required only for the first growing season. Competitive cultivars and increased seeding rates maximize the competitiveness of cardoon against weeds. Several cultural practices can be used for non-chemical weed management in sweet sorghum and kenaf. For all crops, pre-emer... [more]

The production of renewable energy fluctuates in terms of sun and wind and must be supplemented by storage in the system. On an individual basis, i.e., for centralized electricity production and predominantly self-consumption, the use of batteries is considered here. Possible future development scenarios were simulated based on current price relationships (status quo). In the status quo, a selling price for PV electricity of 13 Euro cents (ct)ct/kWh was assumed with a production cost of 11 ct/kWh. The selling price of wind power is 5 ct/kWh with a production cost of 3 ct/kWh. The cost of storing electricity in a battery increases the price by 33 ct/kWh. A price of 20 ct/kWh is assumed for electricity purchases by companies. In the status quo, the use of batteries is not economical given the assumed price relationships. Changing the framework conditions, such as those of the legislature in Germany with the nuclear power phase-out and in the EU with the coal exit and decarbonization, wil... [more]

Co-hydrothermal carbonization (Co-HTC) is an emerging technology for processing multiple waste streams together to improve their fuel properties in the solid product, known as hydrochar, compared to the hydrothermal carbonization (HTC) of those individual streams. Sulfur is considered one of the most toxic contaminants in solid fuel and the combustion of this sulfur results in the emission of SOx. It was reported in the literature that, besides the fuel properties, Co-HTC reduced the total sulfur content in the hydrochar phase significantly. However, the transformation of different forms of sulfur has not yet been studied. Therefore, this study investigated the transformation of different forms of sulfur under the Co-HTC treatment. In the study, the Co-HTC of food waste (FW) and two types of coal wastes (middle bottom (CW1) and 4 top (CW2)) were conducted at 180 °C, 230 °C and 280 °C for 30 min. Different forms of sulfur were measured by using elemental analysis (total sulfur), and a w... [more]

Extracting ethanol by steam directly from fermented solid-state bagasse is an emerging technology of energy-efficient bioethanol production. With continuous solid-state distillation (CSSD) approach, the vapor with more than 25 wt% ethanol flows out of the column. Conventionally, the vapor was concentrated to azeotrope by rectification column, which contributes most of the energy consumption in ethanol production. As an alternative, a process integrating CSSD and vapor permeation (VP) membrane separation was tested. In light of existing industrial application of NaA zeolite hydrophilic membrane for dehydration, the prospect of replacing rectification operation with hydrophobic membrane for ethanol enriching was mainly analyzed in this paper. The separation performance of a commercial PDMS/PVDF membrane in a wide range of ethanol−water-vapor binary mixture was evaluated in the experiment. The correlation of the separation factor and permeate flux at different transmembrane driving force... [more]

In this study, an inter-continental agricultural pellet supply chain is modeled, and the production cost and price of agricultural pellets are estimated and compared against the recent cost and price of wood pellets in the global marketplace. The inter-continental supply chain is verified and validated using an integration of an interactive mapping application and a simulation platform. The integrated model is applied to a case study in which agricultural pellets are produced in six locations in Canada and shipped and discharged at the three major ports in Western Europe. The cost of agricultural pellets in the six locations is estimated to be in the range of EUR 92−95/tonne (CAD 138−142/tonne), which is comparable with the recent cost of wood pellets produced in small-scale pellet plants (EUR 99−109/tonne). The average agricultural pellet price shipped from the six plants to the three ports in Western Europe is estimated to be in a range of EUR 183−204 (CAD 274−305/tonne), 29−42% more... [more]