Agriculture and agro-based industries consume more energy, mainly derived from fossil fuels [...]

Rural energy is an important part of China’s energy system, and, as China’s agricultural modernization continues, integrated agricultural energy systems (AIES) will play an increasingly important role. However, most of China’s existing rural energy systems are inefficient, costly to run, and pollute the environment. Therefore, meeting various agricultural energy needs while balancing energy efficiency and costs is an important issue in the design and dispatch of integrated agricultural energy systems. In conjunction with hybrid energy storage (HES), which has been developed and matured in recent years, this paper proposes a new type of AIES structure and optimal dispatching strategy that incorporates HES, biogas generation (BG), P2G, and an electric boiler (EB) to provide new ideas for problem solving. Firstly, the structure of AIES is introduced and the mathematical model of the equipment of the system is described; then, an economic optimal dispatching model with the objective of min... [more]

The simultaneous firing characteristics of woodchips and spent mushroom substrates (SMS) were studied in a stoker-type industrial boiler. The type of spent substrate intended for combustion consisted of oyster mushrooms. SMS from mushroom farms generally have a high water content. Dryers are therefore used for combustion. The moisture content of SMS was reduced to achieve low moisture to combust sufficiently at about 20%. First, the basic characteristics of the boiler were confirmed by conducting a woodchip combustion test under various operating loads of 30, 50, 70, and 100%. Thereafter, a simultaneous combustion test of woodchips and SMS was performed. During the experiment, exhaust gas concentrations in the boiler combustion chamber were measured, such as the temperature of oxygen (O2), carbon monoxide (CO), and nitrogen oxides (NOx). In addition, industrial and basic analyses were performed on woodchips and SMS. The main differences in the fuel analysis results between woodchips an... [more]

The Common Agricultural Policy defines the framework directions for the structural changes of the agri-food sector until 2030. The main reason for the actions is a fundamental change in the European Union’s approach to environmental protection issues and the dynamically changing conditions on the market for energy and agricultural raw materials. The European Green Deal, the key element of which is the “Farm to Fork” strategy, is the expression of the announced changes. The assumption of the documents is the long-term restructuring and modernization of the EU economy, which will be characterized, among others, by a closed cycle, low greenhouse gas emissions, and food and energy security. The challenges and the current situation in the markets of energy carriers are of significance in the activities of the food industry, which shows a high demand for energy. The aim of the article is to assess the level of consumption and energy efficiency of food industry enterprises in Poland, to ident... [more]

In this study, a newly established bench-scale thermophilic continuously stirred fluidized bed reactor (CSFBR) was applied for anaerobic co-digestion of food waste (FW) with grease trap waste (GTW). The performance of CSFBR regarding stability and treatment efficiency was inspected through a laboratory contrast experiment with two traditional continuous stirred tank reactors (CSTRs). In the OLR range of 3.19−7.41 g COD/L/d, the methane production rate of the thermophilic CSFBR was about as high as that of the thermophilic CSTR. Nevertheless, the thermophilic CSFBR had much lower VFAs (<1000 mg/L) and LCFA concentrations (<100 mg/L) as compared with the thermophilic CSTR. Unlike the mesophilic CSTR, there was no foaming that occurred in the CSFBR during the whole experimental period. The results all suggested that CSFBR simultaneously provided high treatment capacity and process stability in anaerobic digestion with high-lipid loading.

In response to global warming, China has formulated the “double carbon” strategic goals of peaking carbon dioxide emissions before 2030 and reaching carbon neutrality before 2060. The problem of rural carbon emissions is often ignored due to underdeveloped industries and services. In this paper, the carbon emission pathways in the rural areas of Guangdong Province are investigated. Since energy consumption is the main source of carbon emissions, the factor analysis was used to analyze the main factors affecting rural household energy consumption and agricultural production energy consumption. Multiple linear regression was conducted to predict the rural energy consumption demand in Guangdong. Furthermore, the current situation and development trend of rural energy supply, demand and consumption structure, and the potential of renewable energy development were considered to predict carbon emissions in the rural areas of Guangdong. Moreover, the carbon emission pathways in the rural area... [more]

The concept of a bioeconomy can be an opportunity for agricultural and rural development. The objective of this research is to identify groups of family farms which are able to implement the principles of this new development model based on a bioeconomy and to reduce operating costs, especially energy. The time scope of this study covers the period 2004−2020. The data source is the Farm Accountancy Data Network. On the basis of the values of output, family farm income, cash flow, net investment and total inputs (including energy costs), the classes of family farms are indicated. The ranking is based on geographical criteria and the results of panel data models with fixed effects which measure the relationship between energy costs and production, income, cash flow and net investment according to the economic size of the family farm. The results obtained are discussed within the framework of recommendations of the European Commission.

In recent years, growing awareness about environmental issues is pushing humankind to explore innovative technologies to reduce the anthropogenic sources of pollutants. Among these sources, internal combustion engines in non-road mobile machinery (NRMM), such as agricultural tractors, are one of the most important. The aim of this work is to explore the possibility of replacing the conventional diesel engine with an electric powertrain powered by a hybrid storage system, consisting of a small battery pack and a fuel-cell system. The battery pack (BP) is necessary to help the fuel cell manage sudden peaks in power demands. Numerical models of the conventional powertrain and a fuel-cell tractor were carried out. To compare the two powertrains, work cycles derived from data collected during real operative conditions were exploited and simulated. For the fuel-cell tractor, a control strategy to split the electric power between the battery pack and the fuel cell was explored. The powertrain... [more]

Agricultural land and forestland are considered as two largest potential biomass sources for meeting the Renewable Fuel Standard (RFS) mandate for cellulosic biofuels. However, the land use change and greenhouse gas (GHG) savings with both agricultural and forest biomass production are yet to be examined systematically. This paper examines the effects of implementing a 16-billion gallon (60 billion liters) cellulosic biofuel mandate by 2035 on the mix of agricultural and forest biomass, land use change and GHG emissions by using a dynamic partial equilibrium model of the agricultural, forestry and transportation sectors in the US. Our results show that crop residues play a significant role in supplying cellulosic ethanol before 2030, while energy crops are the major feedstocks used for meeting the RFS cellulosic mandate after 2030. Milling and logging residues are economically viable supplements to agricultural biomass for cellulosic ethanol production, though their role in total bioma... [more]

Liquid wastes are generated during production in the milk and cheese industries. During cheese production, whey emerges as a liquid product. Researchers define waste as raw material instead of waste alone. Hence, there is no doubt that the use and management of waste will gain greater importance in the upcoming years. This study discusses the use of whey, which is food waste, in agriculture and the benefits derived from it in terms of energy value. Our research was based on the current literature and the amount of whey that emerged in the dairy industry. For this purpose, the existing literature was evaluated to determine how much waste was produced from whey. The total amount of whey waste in Turkey for 2021 was determined. Afterwards, the amount of potential energy was determined in evaluating these wastes. Turkey’s total amount of potential energy obtained from whey waste was calculated as 570.11 × 106 MJ, with 158.36 × 106 kWh as potential electrical energy. Moreover, it was calcul... [more]

One of the bases of the European policy and energy strategy is the biomass and bioenergy obtained from it. It is estimated that by 2023, the annual demand for biomass will have increased from the current level of 7 EJ to 10 EJ. There are significant differences between estimates of the bioenergy potential due to the fact that the authors of publications do not use consistent methodology and assumptions. Forest biomass, agricultural residues, and energy crops are the three main sources of biomass for energy production. Energy crops are likely to become the most important source of biomass. Land use and its changes are a key issue in the sustainable production of bioenergy as the availability of biomass determines its potential for energy security. This article is a review of the latest publications on the bioenergy potential of the member-states of the European Union. The consumption of energy and its potential were presented, with a special focus on renewable sources, especially biomas... [more]

The article presents the results of research on the range of the impact of a cooling facility on the surrounding ground. An analysis of the heat exchange with the ground and through the building partitions was carried out. The analysis was carried out on the basis of the results of actual field tests carried out throughout the measurement year. The object of the research was an agricultural cold store located in southern Poland. The computational analysis of the interaction between the cooling facility and the ground was based on the numerical elementary balances method. The validation of the calculation model was performed based on the adopted boundary conditions. Calculations for the analyzed variants were carried out on the basis of a geometric model of the cooling facility built in the WUFI®plus program, corresponding to the actual dimensions. The analysis of the energy balance of the studied facility showed that the share of energy flow through the floor to the ground constitutes... [more]

The growth in the number of cars and the increasing demand for fuels require scientific work to develop alternative fuels. The energy crisis, which is becoming more and more evident, is not unimportant. The manuscript presents an analysis of the possibility of using agricultural biofuels to power a diesel engine. The analysis was carried out in relation to the operation of the engine on conventional fuels. The D-241 engine under investigation is mainly used for agricultural tractors. During the tests carried out, the load characteristics of the diesel engine under investigation were determined as a function of fuel type and speed. The concentrations of CO, HC and NOx were analysed. Laboratory tests of the engine were carried out with a wide range of external loads to evaluate measurement errors for the measurement method. Experiments with the engine under investigation have shown that the hourly and specific biofuel consumption of diesel engines increases by an average of 11−16%. CO an... [more]

Most scenarios of climate change in Poland predict an increase in air temperature in the coming years. However, no significant increase in precipitation is forecast. Therefore, an increase in the water needs of plants should be expected, which requires the development of irrigation systems. To precisely determine the schedule of crop irrigation, it is necessary to investigate the water needs of plants and to estimate the prospects of changes in the future. This research aimed to estimate the water needs of Jerusalem artichoke in the period 2021−2050 in the Kuyavia region located in central Poland, where the need for supplementary irrigation is the highest. Based on the calculations, it was found that, in the growing season (21 May−30 September), an increase in the water needs of Jerusalem artichoke, of 26 mm, i.e., 9%, should be expected. The highest increase of 10 mm (i.e., by 16%) is expected in August. The results of our studies are utilitarian in character and can be used for the p... [more]

Numerical simulations were carried out for moist, porous media, intermittent microwave convective drying (IMCD) using a multiphase flow model in porous media subdomains coupled with a forced-convection heat-transfer model in an external hot air subdomain. The models were solved by using COMSOL Multiphysics was applied at the pulse ratio (PR) of 3. Based on drying characteristics of porous media and the distribution of the evaporation interface, IMCD was compared with convection drying (CD). Drying uniformity K, velocity difference, temperature difference, and humidity difference were introduced to evaluate the performance of three models with different inlets and outlet wall curvature. The numerical results show that as the moisture content of slices was reduced to 3 kg/kg, the drying rate in IMCD was 0.0166−0.02 m/s higher than that in CD, and the total drying time of the former was 81.35% shorter than that of the latter. In the late drying stage of IMCD, the core of the sample still... [more]

Renewable energy arises as a tool for the supply of energy to the agriculture sector. Currently, there is a growing concern for the environment. This circumstance has led to technological progress in energy use in relation to natural resources and their availability for all productive sectors, including agriculture. The main objective of this work is to perform analysis from a bibliometric point of view and to analyze scientific advances in renewable energy and agriculture worldwide that have occurred in the last three years (2019−2021). The purpose of this study is to provide an overview of the last three years on the topic in order to contribute to the international scientific community, specifically towards collaboration between authors, institutions, and countries. A keyword analysis using community detection was applied to detect the five main clusters of this research and was largely dedicated to the following topics: renewable energy technologies in agriculture, bioenergy, susta... [more]

The effects of hydrolysis methods (hydrothermal, acid, alkali, hydrothermal-enzyme, acid-enzyme, and alkali-enzyme) on hydrolysate characteristics and photo fermentative hydrogen production (PFHP) of corn straw (CS) and sorghum straw (SS) were investigated. The optimum production of reducing the sugar of straw in different solvent environments was studied by one-step hydrolysis and co-enzymatic hydrolysis pretreatment through a 3,5-dinitrosalicylic acid method. The hydrogen production process by photolytic fermentation of hydrolysates of Rhodobacter sphaeroides HY01 was further analyzed through a gas chromatograph, including the differences in accumulated PFHP yield, chemical oxygen consumption (COD), and volatile fatty acid (VFA) composition. The results showed that the highest reducing sugar yield was obtained by the acid method among one-step hydrolysis. In contrast, acid-enzyme hydrolysis can further increase the reducing sugar yield, which reached 0.42 g·g−1-straw of both straws.... [more]

The temperature difference between day and night in a solar greenhouse is large. Heat in a greenhouse is typically in excess during the day while the temperature is low and the humidity is high at night. This study designs and tests an active heat storage and release air-source heat-pump system with a thermally insulated water tank as the energy storage body. By comparing air temperature and humidity in a test greenhouse with a control greenhouse in typical weather conditions, the power consumption and performance of the system are evaluated. The results show that compared with the control greenhouse, the average daytime temperature of the test greenhouse is lowered by about 3 °C during the operation of the system in typical weather conditions. At night, the average temperature is increased by about 4 °C, and the relative humidity is decreased by about 20%. When optimized, the maximum coefficient of performance (COP) of the system can reach 4.32 in heat storage mode. The nighttime heat... [more]

In this study, predominant bacterial and archaeal populations and their roles during anaerobic mono-digestion of food waste (FW) and co-digestion of FW with straw pellets (SP) at thermophilic temperature (53 ± 1 °C) were assessed by Next Generation Sequencing (NGS) analysis at organic loading rates (OLRs) of 3.0 and 7.0 gVS/L/d. Depending on the seed; results revealed that Firmicutes, Bacteroidetes, and Proteobacteria were, respectively the most prevalent bacterial phyla at both OLRs investigated. On the other hand, Euryarchaeota was dominated by methanogens playing crucial role in biogas production and correlated mainly with the activities of Methanobacteria and Methanomicrobia at class level. Acetoclastic Methanosaetae was the predominant genus at OLR = 3.0 gVS/L/d; however, shared the same predominance with hydrogenotrophic methanogens Methanospirillium at the highest OLR. Although no clear effect in response to straw addition at OLR of 3.0 gVS/L/d could be seen in terms of methanog... [more]

The large volumes of meat and bone meal (MBM) being produced are leading to an increased demand for research into innovative methods of utilizing MBM and obtaining further benefits. The object of this study is to analyze the efficiency of bioethanol and biodiesel production obtained from corn grain fertilized with meat and bone meal produced from animal waste. For the realization of this study, a four-year field experiment was carried out with grain corn fertilized with different doses of meat and bone meal in comparison to fertilization with mineral fertilizers and no fertilization. Fertilization with meat and bone meal should be considered not only for its direct effect but also for the after-effect. The effect of meat and bone meals on obtaining a grain yield higher than that obtained on objects without fertilization and those fertilized with mineral fertilizers was noticeable after applying higher doses from the third year of the study. Fertilization with meat and bone meals did no... [more]

The cultivation of renewable raw materials on arable land is challenged by the ongoing fuel-versus-food debate resulting from increases in maize cultivation, shorter crop rotations and land competition. Accordingly, the current legal framework for biogas production in Germany focuses on limiting cultivation of traditional biogas substrates, such as silage maize, and promoting the use of various alternatives, such as waste materials and by-products. One new sustainable substrate alternative is the use of cereal straw compacted to pellets. Although straw pellets generally have good fermentation properties, they are still rarely used in German biogas production. Since earlier research on agricultural production practices in general has shown that farmers can be divided into groups regarding their acceptance behaviour and the speed to successfully adopt innovative practices and technologies on their farm, this study addresses the research question: How can biogas plant operators in Germany... [more]

The aim of this study was to identify and evaluate the factors influencing the propensity of farm households to accumulate savings, which in this work are treated as a source of financial energy, taking into account socioeconomic characteristics relating to the farmer and their household, as well as farm characteristics. Classification and regression tree analysis (CRT) was used to achieve this goal. The study was conducted on a group of farms in Central Pomerania (Poland) participating in the Farm Accountancy Data Network. Data on 348 farms, obtained through a survey carried out in 2020 using a direct survey questionnaire, were used for the analyses. On the basis of the application of the classification-regression tree method, it was found that income (INC) was the key factor differentiating the studied population in terms of savings, followed by the agricultural area (AREA) and the level of education of the head of the household (EDU). It was also found that, in the case of household... [more]

Agricultural biomass is one of the most important renewable energy sources. As a byproduct of corn, soybean and sunflower production, large amounts of biomass are produced that can be used as an energy source through conversion. In order to assess the quality and the possibility of the use of biomass, its composition and calorific value must be determined. The use of nonlinear models allows for an easier estimation of the energy properties of biomass concerning certain input and output parameters. In this paper, RFR (Random Forest Regression) and SVM (Support Vector Machine) models were developed to determine their capabilities in estimating the HHV (higher heating value) of biomass based on input parameters of ultimate analysis. The developed models showed good performance in terms of HHV estimation, confirmed by the coefficient of determination for the RFR (R2 = 0.79) and SVM (R2 = 0.93) models. The developed models have shown promising results in accurately predicting the HHV of bio... [more]

Lignocellulosic biomass from rice husk (RH) is a renewable resource for fuel production, but it could pose ash-related challenges. This work focused on investigating the effects of pretreatment at different sodium hydroxide (NaOH) concentrations (i.e., 0.0, 0.25, 0.50, 0.75 and 1.00 M) on the calorific values and ash contents of treated RH products, and also finding the optimal torrefaction conditions. The results showed that alkaline pretreatment by sodium hydroxide (NaOH) reduced the ash content in the RH samples by over 85 wt%. Due to its relatively excellent calorific values and low ash content, the RH sample with 0.25 M NaOH pretreatment (i.e., RH-25) was chosen as a starting feedstock in the subsequent torrefaction experiments as a function of 240−360 °C for holding time of 0−90 min. In addition, the surface properties by scanning electron microscopy—energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier-transform infrared spectroscopy (FTIR) were also used to observe the ele... [more]

The purpose of this study was to determine the feasibility of using a hydrophytic method to degrade selected pesticides (pyraclostrobin and boscalid) from agricultural waste (wastewater) and to evaluate their removal efficiency. This will allow the recovery of water and raw materials from agricultural wastewater. In addition, a biopreparation was used to increase the efficiency of the process and the rate of degradation and reduce the half-life of the compounds in wastewater. Pesticides, which are commonly used in agriculture, were selected for the experiments. The study was conducted on a pilot scale, in two identical hydrophytic treatment systems supported and not supported by microorganisms. At the same time, in order to identify pesticides, an analytical method based on liquid chromatography-tandem mass spectrometry was optimized, enabling the determination of applied pesticides in wastewater with satisfactory sensitivity, accuracy and precision. The kinetics of pesticide decomposi... [more]