Industrial hemp (Cannabis sativa L.) production and the hemp-based industry are set for expansion. Hemp is cultivated for valuable fibers from stems and oil from seeds, used in various industrial applications. Recently, hemp has been grown for energy production due to its high biomass and seed yields. Hemp oil is suitable for biodiesel production through transesterification, while hemp biomass serves as a solid fuel or raw material for bioethanol, biohydrogen, and biogas production. This paper provides a comprehensive review of hemp seed and biomass pretreatment, oil extraction, and biofuel production methods. Pretreatment methods for hemp seed and biomass are largely unexplored, and innovative methods require detailed economic analysis before commercialization. Research on hemp oil extraction is sparse and lacks comparative analyses of different techniques regarding yield and quality. Advanced methods yield more oil in shorter times than conventional techniques. Advanced solvent extraction yields more oil than screw pressing and maceration but less than Soxhlet extraction. Transesterification of hemp oil for biodiesel typically uses base catalysts, either homogeneous or heterogeneous, but novel methods have yet to be applied. Other biofuels are produced by thermochemical (torrefaction, pyrolysis, gasification) and biological (fermentation, anaerobic digestion) processes. A comparative analysis of biofuel yields and primary energy recovery potentials of different hemp components is needed to optimize biomass utilization in bioenergy production. Despite the substantial benefits of hemp biofuel production, challenges such as legal and regulatory barriers, economic competition with high-value products, production costs, environmental trade-offs, technological advancement, and public perception need to be addressed.
Potato production under rainfed conditions requires sustainable management strategies, including integrated agroecological approaches that combine nutrient inputs with plant-based biopreparations to maintain tuber yield and quality while reducing foliar disease pressure. This three-year field study (2022–2024) evaluated the effects of garlic (Allium sativum) and horsetail (Equisetum arvense) teas, alone or combined with compost derived from medicinal plant residues, on growth, yield, tuber quality, and disease incidence of the traditional variety Desiree under rainfed conditions in South Banat, Serbia. Treatments included garlic tea (GT, 2 L/ha), horsetail tea (HT, 2 L/ha), a combination of both teas (GHT, 2 + 2 L/ha), compost alone (Comp, 100 t/ha), compost combined with both teas (CompGHT), and an untreated control. The combined CompGHT treatment consistently enhanced tuber number per plant (8.1 vs. 5.0), average tuber weight (62.5 vs. 38.7 g), total tuber weight (≈506 vs. 193 g/plant), and marketable yield (35.2 vs. 21.8 t/ha), representing a 52–62
Industrial hemp (Cannabis sativa L.) is gaining recognition for its versatility, particularly as a source of fiber, seeds, and bioenergy. While the stems are predominantly utilized for fiber production, the residual biomass from processing (e.g., leaves, hurds, and other by-products) can be converted into solid biofuels or further valorized through bioethanol and biogas production. At the same time, industrial hemp oil (IHO) can be converted into biodiesel via transesterification. This review examines seed pretreatment, oil extraction, biodiesel production, and the physicochemical properties of the resulting fuels. Although interest in IHO has increased in recent years, relatively few studies compare advanced extraction approaches with traditional ones in terms of yield or oil quality. Most work on IHO transesterification still relies on base catalysts, whether homogeneous or heterogeneous, whereas newer catalytic strategies remain less explored. Available findings are compared here to highlight variations in oil yield, reaction conditions, and fuel properties among different cultivars. These characteristics depend not only on processing methods but also on cultivar choice, growing conditions, and agricultural practices. Looking ahead, a more integrated use of industrial hemp biomass in biorefinery concepts could help maximize value from oil, seed cake, and other residues. Such approaches align with the Sustainable Development Goals by encouraging resource efficiency and environmental stewardship. Even so, challenges remain, particularly scaling up production, refining processes, and ensuring social responsibility throughout the value chain.
Basil (Ocimum basilicum) is sensitive to water quality, particularly in drought-prone regions, and exhibits pronounced metabolic plasticity in response to salinity stress, which significantly affects its growth and aromatic profile. Two genotypes (Greek, Sweet) were cultivated under controlled conditions and irrigated with rainwater enriched with NaCl (0, 40, and 80 mM). Volatile organic compounds (VOCs) were analyzed directly from native plant material using headspace gas chromatography–mass spectrometry (HS-GC-MS) in scan mode. Nineteen VOCs were identified, revealing distinct genotype-specific chemotypes: sesquiterpenes predominated in Sweet (70.39%) and phenols in Greek basil (59.15%). Increasing salinity systematically enhanced monoterpene and phenolic fractions while reducing sesquiterpene abundance. Key compounds, including eucalyptol, β-pinene, cis-β-farnesene, and eugenol, showed pronounced salinity-dependent modulation, indicating their role in stress adaptation and interplant signaling. These findings provide insights into genotype-specific VOC responses under salinity and highlight rainwater as a suitable irrigation matrix for controlled studies. Tested basil genotypes showed a broad and shifting response to salinity—its compounds change in complex, genotype‑dependent ways, with some molecules rising and others declining, reflecting both stress adaptation and altered chemical signaling.
Biomass and plastic waste pose severe environmental challenges, contributing to soil, water, and air pollution. A promising circular economy approach involves converting these waste materials into reusable, carbon-rich products. In this study, biochars were produced via the pyrolysis of agricultural wastes from corn, tobacco, and tomato-biomass sources that are rarely employed for this purpose. To investigate improvements in physicochemical properties, co-pyrolysis was performed with high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), and their mixture (PsMix) at 10% and 50% weight ratios. The novelty of this work lies in the combined treatment of underexplored agricultural residues with mixed plastic waste streams, reflecting real industrial conditions where pre-sorting is uncommon. The methodology included systematic evaluation of carbon content and calorific values, alongside morphological characterization by SEM. The specific surface area and pore size distribution were assessed through the Brunauer-Emmett-Teller method. Results demonstrated that co-pyrolysis increased the carbon content up to ~70%. Some selected combinations, such as corn with 10% PsMix (32.7 MJ/kg) and tobacco with 10% HDPE (27.4 MJ/kg), reached levels comparable to coke. Moreover, co-pyrolysis significantly improved the specific surface area, with values up to 204.2 m2/g (tobacco + 10% PP) and 197.2 m2/g (tomato + 50% PS), suggesting suitability for medium- to high-performance adsorption applications. The results of these investigations showed that co-pyrolysis of agricultural and plastic waste produces biochar with fuel characteristics, but also with adsorption properties. In addition, the degradation of accumulated quantities of these types of waste contributes to sustainable solutions in the circular economy.
