Quantitative models of hydrolysis conversion efficiency and biomass crystallinity index for plant breeding

In conjunction with improvements to processing technology, selective breeding can be used to increase bioenergy yield potential either through an increase in total harvestable biomass or by modifying biomass conversion efficiency. In this study, the measurement of biomass composition (lignin, cellulose and hemicellulose) and proximate (fixed carbon, volatile matter, ash and moisture contents) components was conducted on leaf and tissue samples from diverse Sorghum bicolor genotypes across two environments. Multiple regression analysis was used to create models that predict two biomass conversion traits: hydrolysis yield potential (HYP) and crystallinity index (CI). CI model variables included tissue type, ash and lignin. HYP model variables included tissue type, ash, cellulose and volatile matter. The presence of ash content in all models was a salient finding of our study. Given that several models were able to predict HYP and CI in alternate grow‐out years, these models may be useful in selective breeding programmes aimed at sorghum bioenergy feedstock improvement through increased conversion efficiency.     

Immediate Effects of Logging,Mounding, and Removal of Logging Residues on Epixylic Species in Managed Boreal Norway Spruce Stands in Southern Finland

The immediate effects of bioenergy harvesting methods on epixylic species were studied in mature managed Norway spruce dominated forests in southern Finland. The treatments included logging, residue harvesting, and soil preparation as either mounding or mounding combined with stump harvesting. Altogether, 110 logs and 440 species sample plots on logs were inventoried before and after logging, and after soil preparation treatments. Logging decreased the cover and species richness in all epixylic species groups. The soil preparation decreased the cover of macrolichens, while stump harvesting was significantly most devastating both for cover and richness in bryophytes. We suggest that bioenergy harvesting critically affects the epixylic species, and therefore the use of less devastating methods and compensation for the loss of coarse woody debris is recommended on a landscape level.     

Economic feasibility of and vegetation responses to biomass harvest in managed loblolly pine plantations

We evaluated two biomass harvest methods, (1) Whole Tree Thinning (WTT; third-row thinning), and (2) Whole Tree Thinning with Fuelchips (WTTF; third-row thinning plus remove all accessible hardwood stems >2.5 cm diameter at breast height and understory shrubs in thinned area of stand) in a 21-year-old loblolly pine (Pinus taeda L.) plantation in northwest Florida for their harvesting yields and productivities, costs, and effects on groundcover. Both WTT and WTTF produced similar quantities of roundwood (~70 Mg ha^?1) and chips (8.43–13.12 Mg ha^?1) without significantly added operational time (15.77–28.12 Mg h^?1). On-board costs of chip production (US$6.93 to 10.60 Mg^?1) and total cost of roundwood and chip production (~22.5 US$ Mg^?1) of the two harvest methods also did not differ significantly. Following either WTT or WTTF, overall percent groundcover recovered within 6 months. While shrub and grass cover were similar, forb cover in WTT increased significantly following six months of harvests. Importantly, the study suggests that biomass removal is an attractive option that could be integrated with traditional silvicultural thinning methods to manage vegetation and alleviate hazardous fuel and wildfire conditions, leading to improved forest health.     

中国各省市区秸秆资源管理政策发展述评

对2003—2015年7月各省市区发布的122份秸秆资源管理政策文件进行综合述评。各省市发布的秸秆管理政策文件数与秸秆产量有关,但并非是正相关关系。对秸秆禁烧管理的政策文件约占省市区所有秸秆政策文件的41%,制订了对责任人和单位严厉的财政处罚措施。为减少焚烧、促进资源循环利用,天津、河北、黑龙江、上海、江西、山东、广东和江苏等地陆续出台了秸秆利用总体规划和相关实施方案;各省市区根据其具体条件,制订了促进秸秆还田、饲料化、发电及生产沼气等多项综合利用鼓励政策;天津、河北、吉林、上海、安徽、河南、重庆和四川对重点推广秸秆利用技术给予较高的财政补贴,不但引导了农民自行开展秸秆综合利用,而且促进了秸秆利用产业化发展。本研究认为,秸秆禁烧的关键不在"禁",而在"用",建议各省市区制订因地制宜的秸秆综合利用规划,总结当前政策实施现状和存在问题,制订更合理而有效的管理政策,促进研发和推广适宜的秸秆综合利用技术。     

Greenhouse Gas Emissions following Conversion of a Reclaimed Minesoil to Bioenergy Crop Production

This study provides a comparative assessment of greenhouse gas (GHG) emissions when converting a reclaimed minesoil that was previously under meadow to miscanthus (Miscanthus  × giganteus ) and maize (Zea mays L.) land uses in Ohio, USA. Additionally, effluent from an anaerobic digester at rates of 0, 75, 150, and 225 kg N ha⁻¹ rates was also assessed for C and nutrient fertilization. Results from the study show that land use conversion to maize had the highest net release of GHG equivalent of 6·6 Mg CO_2equ ha⁻¹ y⁻¹, on average, across effluent application rates. Under miscanthus land use with no and high effluent application rates, net GHG equivalent on average was 4·3 Mg CO_2equ ha⁻¹ y⁻¹, which was larger when compared with that under the meadow land use (1·6 Mg CO_2equ ha⁻¹ y⁻¹). Miscanthus land use under medium rates of effluent application had similar net GHG equivalent (7·1 Mg CO_2equ ha⁻¹ y⁻¹) to the maize land use. The application of effluent did increase CO₂–C and N₂O–N emissions; but increases in above‐ground–below‐ground biomass production (1·6 Mg C ha⁻¹) in the meadow land use and C input from effluent retained in the soil in the miscanthus and maize land uses offset most of the effluent‐induced GHG equivalent emissions. Contribution of cumulative N₂O–N to GHG equivalent emissions in general was 11% when no effluent was applied and 22% when effluent was applied across land uses. Findings from this study show that land use changes from antecedent meadow to maize and miscanthus during the first year of establishment would result in net increase of GHG emissions. Published 2017. This article is a U.S. Government work and is in the public domain in the USA     

囊盘菌(Ascocoryne)挥发性气体成分多样性及其产烃分析

[目的]内生真菌紫胶囊盘菌(菌株NRRL 50072)首次被发现能产生石化燃料类似成分的挥发性有机代谢产物,这为生物质能源的发展开辟了新的途径,但囊盘菌属的真菌是否都具有该类代谢属性需要进一步明确。[方法]通过组织表面消毒分离囊盘菌不同菌株,经最大似然法构建分子系统发育树明确亲缘关系,利用顶空固相微萃取方法结合气质联用技术(HSSPEM-GC-MS),进行挥发性成分测定和分析。[结果]不同囊盘菌菌株均能产生挥发性烃、醇、酯、醛、酮和酸等代谢产物,但产物存在高度的多样性,即使近缘的菌株之间其挥发性产物也存在很大差异。[结论]囊盘菌属真菌可能普遍具有产挥发性烃类的能力,但其代谢产物种类具有菌株专化性。因此,发现或遗传工程创造目标新菌株资源是深入研究和开发利用囊盘菌真菌生物柴油的重要基础。     

系统动力学在生物质能源产业发展研究中的应用

为促进中国生物质能源产业协调、可持续发展,文中从产业发展影响研究、产业发展政策研究、产业发展优化研究3个方面对系统动力学在生物质能源产业发展研究领域中的应用进行了综述和分析,提出在今后研究中针对产业发展影响研究应深入到对于社会发展具体方面的影响研究、针对产业发展政策研究应加快探究如何实现产业发展过程中市场和政府作用的平衡、针对产业发展优化研究应引入情景分析等多元方法的应用。此外,文中还讨论了系统动力学在林木生物质能源产业发展研究中的适用性。     

生物质能发电技术现状与展望

文章综述了物质燃烧发电、生物质气化发电、沼气工程发电等生物质能发电技术及其发展现状和存在的问题。生物质能发电技术的加速发展,实现了大量废弃生物质能的利用。在我国电力短缺的条件下,生物质能发电将有广阔的发展前景。     

全球生物质能资源评价

随着全球能源供需矛盾的日益突出,人类对开发利用各类新能源寄予厚望,生物质能就是其中之一。生物质能的发展对保障能源安全、培育新的经济增长点、促进农村生活水平的提高等具有积极意义。不过,对生物质能资源的不合理开发也可能会威胁粮食安全,并可能对生态环境造成不利影响。本文对全球生物质能资源进行了系统评价,认为目前以粮食为主要原料的生物质能发展模式不可持续,应积极发展基于纤维素乙醇的不消耗粮食的第二代生物燃料技术。     

纤维素类能源草在京郊地区的经济效益与生态价值评价

纤维素类能源草是一类重要的能源植物与良好的生物质资源。对柳枝稷、荻、芦竹3种纤维素类能源草从农业种植到纤维素乙醇制备的整个过程进行了经济效益与生态价值的初步评价,结果表明,以柳枝稷、荻、芦竹为原料,每制备1.00 t纤维素乙醇的经济效益分别为4 147.85,1 185.08,2 019.76元,柳枝稷最优,芦竹次之,荻再次之;每制备1.00 t纤维素乙醇所需种植的柳枝稷、荻、芦竹的大气净化生态价值分别为4 639.28,4 351.25,4 320.39元,柳枝稷最优,荻次之,芦竹再次之;3种纤维素类能源草均具有强大的固定大气CO₂的能力,对于降低温室气体CO₂浓度、促进土壤碳的积累具有积极作用。