Global Change Biology Bioenergy最新文献

Forest management in drained forested peatlands can negatively affect water quality due to the increase in exports of organic matter and nutrients. Therefore, new methods to alleviate this impact are needed. In laboratory conditions, biochar has been shown to be a strong sorbent of organic and inorganic nutrients due to its high surface area and ion-exchange capacity. However, evidence of the adsorption capacity in field conditions is lacking. Here, we studied the water purification performance of two different biochar feedstocks (wood- and garden residue-based) in a 10-day laboratory experiment where we incubated biochar with runoff water collected from drainage ditches in clear-cut peatland forests. We measured changes in pH and concentrations of inorganic phosphorus (PO₄), total dissolved nitrogen (TDN), and dissolved organic carbon (DOC). The biochar with the best adsorbent capacity in the laboratory experiment was then tested in field conditions in a replicated catchment-scale experiment, where both clear-cutting and ditch cleaning were performed. We determined the nutrient concentration of water at the inlet and outlet of biochar filters placed in outflow ditches of four catchments. We found that under laboratory conditions wood-based biochar efficiently adsorbed TDN and DOC, however, it released PO₄. Furthermore, we found that the biochar filters reduced TDN and DOC concentration in field conditions. However, the percentage decrease in concentration was dependent on the initial concentrations of nutrients in the water and could be considered low. Moreover, we found that the biochar in the filters increased in TN content over the course of the experiment. This suggests that a wood-based biochar filter has the potential to be a water protection tool for reducing the export of nutrients from catchments with high nutrient concentration. And that the biochar from the ditches could be applied back to the regenerating forest catchment as a potential soil amendment, closing the nutrient cycle.

Owing to the enormous consumption of petroleum products and their environmental polluting nature, attention has been given to seeking alternative resources for the development of sustainable products. Biomass is a renewable source that can be converted to a variety of fuels and chemicals by different approaches, which are the best replacements for traditional petroleum-derived products. Pyrolysis is a process in which chemical bonds of biomass macromolecules such as cellulose, hemicellulose, and lignin, are fractured into small molecular intermediates under high pressure, and results bio-oil, biochar, and fuel gases as desired products. Of these pyrolysis products, bio-oil is the primary product that usually contains large amounts of oxygen and nitrogen compounds that hinder its application potential. Catalytic pyrolysis is a beneficial method that is reported to alter the constituents and quality of bio-oil and to upgrade them for diverse applications. Catalytic hydropyrolysis and copyrolysis of biomass are an alternative approaches to overcome the drawbacks raised toward product formation in the pyrolysis process. Layered double hydroxides (LDH) and their derived forms are well-known catalytic/catalytic support materials for various chemical reactions due to their superior properties, such as easy preparation, thermal stability, and tuneable acid/base properties. This review summarizes the progress in the utilization of as-synthesized LDH and their modified forms such as mixed metal oxides and functionalized/composite materials as active catalysts for the pyrolysis of various biomass sources.

Switchgrass (Panicum virgatum L.) production for biofuel has the potential to produce reasonable yields on lands not suited for conventional agriculture. We assessed nine switchgrass cultivars representing lowland and upland ecotypes grown for 11 years at a site in the upper Midwest USA for belowground differences in soil carbon and nitrogen stocks, soil organic matter fractions, and standing root biomass to 1 m depth. We also compared potential nitrogen mineralization and carbon substrate use through community-level physiological profiling in surface soils (0–10 cm depth). Average yields and standing root biomass differed among cultivars and between ecotypes, but we found no significant cultivar-related impacts on soil carbon and nitrogen stocks, on the distribution of particulate and mineral-associated soil organic matter fractions, nor on potential nitrogen mineralization or microbial community-level physiological profiles. That these traits did not differ among cultivars suggests that soil carbon and nitrogen gains under switchgrass are likely to be robust with respect to cultivar differences, and to this point not much affected by breeding efforts.

Synergistic fermentation of coal and corn straw is an effective tool to increase biomethane production. However, a large gap exists between the biomethane production conditions of corn straw filling coal mine goafs and laboratory experiments. In order to determine the effect of the field environment on synergistic biomethane production, biomethane production experiments with coal and corn straw were carried out under different conditions to find the key factors restricting the potential of biomethane production. The obtained results showed that various bacterial sources had significant influences on the biomethane production of coal and corn straw, and domesticated bacterial sources provided fermentation systems with more efficient biomethane production capacities than mine water sources. Biomethane production of coal and corn straw was relatively high under mixed conditions, but it was also promoted under unmixed conditions. Different inorganic minerals had different effects on synergistic biomethane production, which varied. For example, calcite, montmorillonite, and kaolin are common minerals in coal-bearing strata that significantly enhance synergistic biomethane production of coal and corn straw. However, pyrite was found to significantly inhibit the synergistic biomethane production effect of coal and corn straw. Highly metamorphosed anthracite coal also presented biomethane production potential when stimulated by corn straw as a carbon source. The obtained results revealed the influences of different field conditions on the biomethane production of coal and corn straw and provided a reference for the field application of corn straw filling in coal mine goafs.

Invasive alien plant species (IAPS) are a global problem, representing a threat to ecosystem functioning, biodiversity, and human health. Legislation requires the management and eradication of IAPS populations; yet, management practices are costly, require several interventions, and produce large amounts of waste biomass. However, the biomass of eradicated IAPS can become a resource by being used as feedstock for biochar production and, at the same time, implementing the management of IAPS. Here we carried out an in-depth characterization of biochar produced at 550°C derived from 10 (five woody and five herbaceous) widespread IAPS in the central-southern Alps region to determine their potential applications for soil amendment, soil remediation, and carbon storage. Biochar was produced at a laboratory scale, where its physicochemical characteristics, micromorphological features, and lead adsorption from aqueous solutions were measured. To investigate any possible trade-offs among the potential biochar applications, a principal component analysis was performed. IAPS-derived biochars exhibited relevant properties in different fields of application, suggesting that IAPS biomass can be exploited in a circular economy framework. We found coordinated variation and trade-offs from biochars with high stability to biochars with high soil amendment potential (PC1), while the biochar soil remediation potential represents an independent axis of variation (PC2). Specifically, IAPS-derived biochar had species-specific characteristics, with differences between the woody and herbaceous IAPS, the latter being more suitable for soil amendment due to their greater pH, macronutrient content, and macropore area. Biochar derived from woody IAPS showed a greater surface area, smaller pores, and had higher lead adsorption potentials from aqueous solutions, hinting at their higher potential for heavy metal pollution remediation. Moreover, biochar derived from woody IAPS had a higher fixed carbon content, indicating higher carbon stability, and suggesting that their biochar is preferable for carbon sequestration in the view of climate change mitigation.

Bioenergy with carbon capture and geological storage (BECCS) is considered one of the top options for both offsetting CO₂ emissions and removing atmospheric CO₂. BECCS requires using limited land resources efficiently while ensuring minimal adverse impacts on the delicate food-energy-water nexus. Perennial C4 biomass crops are productive on marginal land under low-input conditions avoiding conflict with food and feed crops. The eastern half of the contiguous U.S. contains a large amount of marginal land, which is not economically viable for food production and liable to wind and water erosion under annual cultivation. However, this land is suitable for geological CO₂ storage and perennial crop growth. Given the climate variation across the region, three perennials are major contenders for planting. The yield potential and stability of Miscanthus, switchgrass, and energycane across the region were compared to select which would perform best under the recent (2000–2014) and future (2036–2050) climates. Miscanthus performed best in the Midwest, switchgrass in the Northeast and energycane in the Southeast. On average, Miscanthus yield decreased from present 19.1 t/ha to future 16.8 t/ha; switchgrass yield from 3.5 to 2.4 t/ha; and energycane yield increased from 14 to 15 t/ha. Future yield stability decreased in the region with higher predicted drought stress. Combined, these crops could produce 0.6–0.62 billion tonnes biomass per year for the present and future. Using the biomass for power generation with CCS would capture 703–726 million tonnes of atmospheric CO₂ per year, which would offset about 11% of current total U.S. emission. Further, this biomass approximates the net primary CO₂ productivity of two times the current baseline productivity of existing vegetation, suggesting a huge potential for BECCS. Beyond BECCS, C4 perennial grasses could also increase soil carbon and provide biomass for emerging industries developing replacements for non-renewable products including plastics and building materials.

Camelina [Camelina sativa (L.) Crantz] is a Brassicaceae oilseed that is gaining interest worldwide as low-maintenance crop for diverse biobased applications. One of the most important factors determining its productivity is climate. We conducted a bioclimate analysis in order to analyze the relationship between climatic factors and the productivity of spring-type camelina seeded in the spring, and to identify regions of the world with potential for camelina in this scenario. Using the modelling tool CLIMEX, a bioclimatic model was developed for spring-seeded spring-type camelina to match distribution, reported seed yields and phenology records in North America. Distribution, yield, and phenology data from outside of North America were used as independent datasets for model validation and demonstrated that model projections agreed with published distribution records, reported spring-seeded camelina yields, and closely predicted crop phenology in Europe, South America, and Asia. Sensitivity analysis, used to quantify the response of camelina to changes in precipitation and temperature, indicated that crop performance was more sensitive to moisture than temperature index parameters, suggesting that the yield potential of spring-seeded camelina may be more strongly impacted by water-limited conditions than by high temperatures. Incremental climate scenarios also revealed that spring-seeded camelina production will exhibit yield shifts at the continental scale as temperature and precipitation deviate from current conditions. Yield data were compared with indices of climatic suitability to provide estimates of potential worldwide camelina productivity. This information was used to identify new areas where spring-seeded camelina could be grown and areas that may permit expanded production, including eastern Europe, China, eastern Russia, Australia and New Zealand. Our model is the first to have taken a systematic approach to determine suitable regions for potential worldwide production of spring-seeded camelina.

‘Marginal lands’ are low productivity sites abandoned from agriculture for reasons such as low or high soil water content, challenging topography, or nutrient deficiency. To avoid competition with crop production, cellulosic bioenergy crops have been proposed for cultivation on marginal lands, however on these sites they may be more strongly affected by environmental stresses such as low soil water content. In this study we used rainout shelters to induce low soil moisture on marginal lands and determine the effect of soil water stress on switchgrass growth and the subsequent production of bioethanol. Five marginal land sites that span a latitudinal gradient in Michigan and Wisconsin were planted to switchgrass in 2013 and during the 2018–2021 growing seasons were exposed to reduced precipitation under rainout shelters in comparison to ambient precipitation. The effect of reduced precipitation was related to the environmental conditions at each site and biofuel production metrics (switchgrass biomass yields and composition and ethanol production). During the first year (2018), the rainout shelters were designed with 60% rain exclusion, which did not affect biomass yields compared to ambient conditions at any of the field sites, but decreased switchgrass fermentability at the Wisconsin Central–Hancock site. In subsequent years, the shelters were redesigned to fully exclude rainfall, which led to reduced biomass yields and inhibited fermentation for three sites. When switchgrass was grown in soils with large reductions in moisture and increases in temperature, the potential for biofuel production was significantly reduced, exposing some of the challenges associated with producing biofuels from lignocellulosic biomass grown under drought conditions.

This article reports the results of a discrete choice experiment with 183 German biogas plant operators designed to elicit the respondents' plans for biogas utilization pathways after the end of guaranteed feed-in tariffs. Participants could choose between ‘flexibilization’ for demand-based electricity generation and conversion to biomethane upgrading for direct feed-in into the natural gas grid. A binomial logit model revealed a 37% probability of switching to biomethane upgrading. These plants are characterized by higher capacities, several involved shareholders, secured succession, costly digestate disposal and belonging to the upper performance quartile. Mixed logit estimations conducted separately for the two investment concepts revealed a very high overall willingness to invest: 71% for flexibilization and 82% for biomethane upgrading. The respondents demand a return on investment of 19% for flexibilization and 26% for biomethane upgrading. Within the flexibilization, twofold overbuilding (installed capacity equals 2 times the rated power) is clearly preferred to fivefold overbuilding. For the biomethane upgrading, private ownership of the upgrading plant is preferred to a joint investment in a central upgrading facility. Limiting the use of energy crops reduces the propensity to invest in both models, while a longer utilization period enhances it. The respondents consider lack of planning reliability as the biggest obstacle to invest, followed by long approval procedures and high investment costs due to restrictive legal requirements.

With rapid growth of global population, meeting the increasing demand for food has become a significant challenge. This challenge is further compounded by limited arable land and the necessity to address the nutritional needs of both humans and animals. However, the utilization of straw biomass, which is readily available as an agricultural by-product, presents a sustainable solution to this problem. Microbial fermentation has emerged as a highly effective method for converting non-food biomass into protein, particularly known as single-cell protein (SCP). Compared to traditional protein sources, SCP production through microbial fermentation is rapid and efficient, and requires minimal land resources. This review provides a comprehensive review of the research advancements in SCP from agricultural biomass, including pretreatment methods, microbial strains, and fermentation processes involved in the bioconversion of straw biomass. Due to the complexity of straw-based biomass (SBB), it is essential to customize industrial strains and optimize the fermentation process to achieve the highest protein yield and productivity. Additionally, improving the compatibility between tailored processes and cost-effective industrial strains can lead to the production of protein substitutes that are not only highly nutritious but also economically viable. Hence, the application of SCP derived from SBB presents a dual solution by reducing the need for managing agricultural residues and providing a sustainable source of protein. However, the production of SCP from SBB also has some limitations, such as protein-synthesis efficiency, production cost, and difficulty to scale-up the production process. In the future, there is great potential for significant advancements in the targeted conversion of SBB into protein by customizing high-performance microbial strains. Several sensor and machine learning technologies will predict and monitor real-time dynamic changes in the fermentation process of SBB, offering an opportunity to improve the production of sustainable SCP in an environmentally friendly and precise manner.