Journal of Energy Bioscience 2025, Vol.16, No.2, 53-63 http://bioscipublisher.com/index.php/jeb 57 can be further enhanced by using biological and physicochemical additives, such as enzymes or immobilizing microorganisms on biofilters, to intensify biogas production. Moreover, the integration of anaerobic biorefinery concepts can generate not only bioenergy but also high-value biochemical products from the same feedstock, thereby improving the overall economic feasibility of the process. 5.3 Potential of hemp for biohydrogen through gasification Hemp also holds promise for biohydrogen production through gasification processes. Gasification, particularly microwave-assisted gasification (MAG), is a novel and promising technology for converting biomass into biohydrogen and biosyngas. This method offers the potential for high selectivity and efficiency in biohydrogen production, although further research is needed to enhance these aspects and ensure cost-effective industrialization (Arpia et al., 2021). The use of hemp biomass in such gasification processes could contribute to a sustainable bioeconomy by providing a renewable source of hydrogen, which is a clean and efficient energy carrier. The development of optimal operating conditions and system designs for gasification will be crucial in realizing the full potential of hemp for biohydrogen production. 6 Hemp-Derived Biochar for Energy and Soil Health 6.1 Pyrolysis of hemp biomass to produce biochar Pyrolysis is a thermochemical process that converts biomass into biochar, syngas, and bio-oil by heating it in the absence of oxygen. Hemp biomass, due to its high cellulose and lignin content, is an excellent feedstock for biochar production. The pyrolysis process can be optimized by adjusting parameters such as temperature, heating rate, and residence time to maximize biochar yield and quality. For instance, slow pyrolysis at temperatures ranging from 300 ℃ to 600 ℃ has been shown to produce biochar with high carbon content and stability, which is crucial for its application in soil amendment and carbon sequestration (Hoang et al., 2021; Nan et al., 2021). 6.2 Dual benefits: renewable energy source and soil amendment Hemp-derived biochar offers dual benefits as a renewable energy source and a soil amendment. During pyrolysis, the volatile components of hemp biomass are converted into syngas and bio-oil, which can be used for energy production, while the remaining solid fraction becomes biochar. This biochar can be applied to soils to improve fertility, water retention, and crop yields. Studies have demonstrated that biochar application increases soil organic carbon, cation exchange capacity, and water holding capacity, leading to enhanced plant growth and reduced need for chemical fertilizers (Lehmann et al., 2006; Mohan et al., 2018; El-Naggar et al., 2019). Additionally, the use of biochar in soil can mitigate greenhouse gas emissions by reducing the release of CO2, N2O, and CH4 from soils (Stewart et al., 2013; Peters et al., 2015). 6.3 Carbon sequestration potential and sustainability implications The carbon sequestration potential of hemp-derived biochar is significant. Biochar is highly recalcitrant, meaning it decomposes very slowly in soil, thereby locking carbon away for extended periods. This makes it an effective tool for mitigating climate change by sequestering atmospheric CO2. Research indicates that biochar can sequester up to 50% of the carbon from the original biomass, compared to much lower retention rates from burning or natural decomposition (Woolf et al., 2010; Ghodake et al., 2021). Furthermore, the application of biochar to soils not only sequesters carbon but also enhances soil health and productivity, contributing to sustainable agricultural practices. The integration of biochar production with bioenergy systems can create a carbon-negative process, where more carbon is sequestered than emitted, thus offering a sustainable solution to both energy production and climate change mitigation (Sohi, 2013; Stewart et al., 2013). 7 Case Studies 7.1 Example 1: hemp bioethanol project in Europe The cultivation of industrial hemp in Europe has seen significant political support, particularly for bioenergy applications (Figure 2). A notable project involves the production of bioethanol from hemp biomass. The high cellulose content of hemp makes it an excellent candidate for bioethanol production. Studies have shown that hemp biomass can be effectively converted into bioethanol, with various pretreatment technologies enhancing
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