Tandem-ring mill pulverization benefits for enzymatic saccharification of biomass

A vibration mill, called a “tandem-ring mill”, which has cog-ring media in place of the ball medium of a conventional vibration mill, was developed to achieve high-impact pulverization of lignocellulosic biomass for bio-ethanol production. This study investigated pulverization characteristics of various biomass samples of Japanese cedar, eucalyptus, rice straw, rice husk, and reeds using a batch-type tandem-ring mill for 60 min and 100 min pulverizations. The pulverized biomasses were characterized by the mean particle diameter, crystallinity index, and enzymatic saccharification. The mean particle diameter of biomass was decreased rapidly in the first 20 min. Then the biomass mean particle diameter reached around 40 μm by flocculation. Furthermore, the crystallinity indexes of biomasses were decreased by pulverization. Especially, woody biomasses of cedar and eucalyptus were decreased rapidly around 10%, nearly a non-crystalline state. Woody biomasses, Japanese cedar, and eucalyptus showed high saccharification efficiency. Similarly, grass biomasses, rice straw, and rice husks showed high saccharification, aside from reeds. Therefore pretreatment of various biomasses using a tandem-ring mill was suitable for enzymatic saccharification.     

A novel integrated process for hydrogen production from biomass

A novel process, which integrated with biomass pyrolysis, gas–solid simultaneous gasification and catalytic reforming processes, was utilized to produce hydrogen. The effects of gasification temperature and reforming temperature on hydrogen yield and carbon conversion efficiency were investigated. The results showed that both higher gasification temperature and reforming temperature led to higher hydrogen yield and carbon conversion efficiency. Compared with the two-stage pyrolysis-catalytic reforming process, hydrogen yield and carbon conversion efficiency were greatly increased from 43.58 to 75.96 g H₂/kg biomass and 66.18%–82.20% in the integrated process.     

生物质秸秆成型工艺的试验研究

以节能降耗、延长设备使用寿命为出发点,以玉米秸秆和小麦秸秆为原料,对生物质秸秆的不同成型工艺进行了系统的成型试验研究,并对各种成型工艺的能耗进行了分析.结果表明:热压成型的效果最佳,在条件允许的情况下应优先选择热压成型工艺.     

Lignocellulosic biomass gasification technology in China

With the critical worldwide energy shortage and global environment concern, lignocellulosic biomass is regarded as one of the potential renewable energy resources to substitute conventional fossil fuels. Among various thermo-chemical conversion technologies, gasification is now regarded as an advanced and efficient method. Based on the mechanism of biomass gasification, this paper outlines different types of gasifiers that have been developed in China. Air gasification technology has been employed in the rural areas or forestry/agricultural processing entities. Obviously, the product gas for cooking and heating can significantly upgrade the living standard of rural residents. The product gas for heating boiler and generating electricity benefits the forest or agricultural processing enterprises. For China’s sustainable development of energy and environment, multi-cogeneration of heat, electricity and liquid fuels together with chemical feedstock will be a potential direction for efficiently utilizing product gas from lignocellulosic biomass. This means oxygen (including oxygen-enriched air) gasification and steam gasification should be taken into more consideration.     

生物质秸秆预处理技术

生物质秸秆的外形各异,几何尺寸差别较大,使得生物质秸秆的利用受到限制。为了更好地利用生物质能,满足生物质利用技术的需要,要根据具体情况来选择生物质秸秆预处理技术。目前的预处理技术主要有干燥技术、切割技术、粉碎技术、制粒技术以及成型技术。探讨预处理技术,一方面有利于完善、提高生物质技术,另一方面也提高了生物质能的利用率。     

生物质能利用技术的经济性分析

对国内生物质能利用技术的现状进行了简要介绍和分类，以经济评价为基础，对生物质直接燃烧、户用沼气池、生物质气化发电、大中型养殖场沼气工程和垃圾发电等生物质能技术进行了综合分析，提出了根据地方实际，发展不同生物质能技术的建议。     

Costs of biomass pyrolysis as a negative emission technology: A case study

Biomass pyrolysis is a promising method for the creation of biochar, a potentially long‐lived carbon sink, and renewable fuels. While a number of studies of the costs of pyrolysis exist, many fail to value the carbon storage benefit associated with biochar. Here, we evaluate the costs of three types of small‐scale pyrolysis systems (slow and fast, compared with gasification) in Costa Rica. We find that under many combinations of model parameters, fast and slow pyrolysis models are cost‐effective. Net present values are positive for slow pyrolysis at carbon prices above $7 t^?1, indicating that a low carbon price is required to make slow pyrolysis cost‐effective. Likewise, fast pyrolysis is cost‐effective at any positive carbon price. Gasification is generally more costly than fast or slow pyrolysis, and the net present value of the gasification system is only positive at electricity prices over $0.15 kWh^?1 or carbon prices over $150 t^?1. Thus, both fast and slow pyrolysis models are promising methods for atmospheric CO₂ reduction.     

Development of a novel updraft multifuel biomass gasifier

The paper reports the development of a novel multifuel biomass reactor for direct heating applications such as water heating, air heating or steam generation. Studies were conducted on the reactor to maximize its heat release rate by evaluation of the sensitivities of the fuel and charging parameters to firing rate. Maximum firing rates measured for the different fuels were in the range of 8–43 kg/h for the natural draft mode and 45–130 kg/h for the forced draft mode. It is observed that the heat release rate is enhanced by up to 360% by preheating of the charge, increase of the surface-area/volume ratio of the fuel charge, decrease of the charge per feed, and adoption of forced draft mode. For wood, a fuel preheat to 80°C, a surface-area/volume ratio of 600 m^?1 and a charge per feed of 0.5–1.0 kg give a higher heat release and minimize gas temperature fluctuations.     

废弃物及生物质的超临界流体转化技术

综述了用超临界流体进行废弃物和生物质的转化。由于超临界流体的特殊性质，使得用超临界流体进行转化具有效率高、速度快、污染性副产品少的特点，是一种很有实用价值的物料处理和转化技术。     

生物质气化技术比较及其气化发电技术研究进展

生物质能是一种理想的可再生能源,由于其在燃烧过程中二氧化碳净排放量近似于零,可有效地减少温室效应,因而越来越受到世界各国的关注。首先对生物质能的概念及其转化方式进行了简单介绍,着重介绍了生物质气化技术在国内外的研究及应用发展现状,通过对固定床气化炉和流化床气化炉的技术性能的对比．提出了研究开发经济上可行、效率较高的生物质发电系统,是我国今后有效利用生物质能的发展方向。     

Biogas and biomass technology: Energy generation from biomass and waste in the Netherlands

Within the European Community, the interest in energy generation from biomass and waste is increasing. A brief overview is given of several thermal conversion technologies, of biomass production and waste availability in the Netherlands. Based on this, the possibilities for energy generation from biomass and waste in the Netherlands are evaluated.     

生物质热解液化技术经济分析

我国生物质资源十分丰富，但主要以各类农业残余废弃物为主，其特点是能量密度低、分布不集中，如果采用热解液化技术在产地将其先分散转化成生物油，然后再对生物油进行应用或再加工，则就避免了大规模收集和长距离运输生物质所带来的巨大困难。研究分析表明：热解液化设备的规模以每小时可处理2t农业残余废弃物较为适宜，且这种技术在我国具有良好的市场应用前景。     

A novel process simulation model for hydrogen production via reforming of biomass gasification tar

Process modeling and simulation are very important for new designs and estimation of operating variables. This study describes a new process for the production of hydrogen from lignocellulosic biomass gasification tars. The main focus of this research is to increase hydrogen production and improve the overall energy efficiency of the process. In this study, Aspen HYSYS software was used for simulation. The integration structure presented in this research includes sections like tar reforming and ash separation (Ash), combined heat and power cycle (CHP), hydrogen sulfide removal unit (HRU), water-gas shift (WGS) reactor, and gas compression as well as hydrogen separation from a mixture of gases in pressure swing adsorption (PSA). It was found that the addition of CHP cycle and the use of the plug flow reactor (PFR) model, firstly, increased the overall energy efficiency of the process by 63% compared to 29.2% of the base process. Secondly it increased the amount of hydrogen production by 0.518 kmol (H2)/kmol Tar as compared with 0.475 of the base process. Process analysis also demonstrated that the integrated process of hydrogen production from biomass gasification tars is carbon neutral.     

中国生物质能源技术现状与展望

煤燃烧释放了占全球1／3以上的碳,是造成全球气候变暖的元凶之一。中国75％的电力源自煤炭；煤变油更会加快煤炭的枯竭速度!生物质能源再次浮出水面一次性化石燃料资源的日趋枯竭使人们不得不把注意力转向可再生能源。目前可再生能源中的生     

ILGAR – A novel thin-film technology for sulfides

Ion layer gas reaction (ILGAR), a novel thin-film technology for sulfides is introduced. Its peculiarity is the low-temperature conversion of a solid metal salt precursor into a sulfide compound by reaction with gaseous H₂S. The capability of this technique is demonstrated by the preparation of CdS, which is either of cubic or hexagonal polycrystalline structure. Spectralphotometric measurements reveal a high optical band gap of 2.78 eV. A subsequent annealing process reduces this value to 2.45 eV. This fact as well as XRD results indicate a nanocrystalline structure of the ILGAR-deposited CdS thin films.     

煤与生物质共热解工艺的研究进展

热解是将固态原料转化为液体燃料、可燃气和焦的重要途径,是实现生物质资源清洁、高效利用的重要技术。将生物质与煤混合共热解是生物质资源利用的重要方法,两者混合热解不仅有助于降低CO_2的排放量,还能有效地解决能源短缺和环境污染带来的问题。文章综述了煤与生物质共热解技术的研究进展,系统地介绍了共热解过程中煤与生物质的相互作用以及热解温度、混合比例、滞留时间、升温速率、矿物质成分、物料粒径和热解反应器类型等因素对热解过程的影响,并对煤与生物质共热解技术的发展前景进行了展望。     

生物质水热技术研究现状及发展

生物质水热转化技术作为一种新的生物质利用技术,在亚临界或超临界水下,将生物质直接转化为高品位气态、液态和固态产物。该技术具有原料适应性广、低成本和高转化率等特点,具有很好的应用前景。文章综述了近年来生物质水热技术研究的最新进展,分别对水热液化、水热气化和水热碳化3方面内容进行分析,对目前存在的问题提出了建设性的意见。     

生物质能的转化和利用技术研究

能源短缺成为影响中国未来发展的主要问题之一。生物质能的应用有助于解决我国能源短缺的问题，同时能够减小化石燃料使用带来的负面影响。文章主要介绍了生物质能的概念、生物质能利用的意义及生物质能的转化和利用技术，而且还提出实际利用过程中需要解决的问题以及未来的发展方向——以生物质为核心的多联产系统。     

生物质合成气发酵生产乙醇技术的研究进展

20世纪70年代以来,开发低成本、可再生的能源已成为各国的研究热点。以生物质为原料生产的燃料乙醇是一种很有应用潜力的能源。文章简要讨论了生物质合成气发酵生产乙醇的技术途径．分析了该技术的优点、工艺过程、生产成本和市场化进程,特别介绍了美国BRI公司和密西西比乙醇公司（ME）在生物质合成气发酵生产乙醇方面所做的工作;同时,指出了我国发展生物质合成气发酵技术的必要性和应用前景。     

生物质户用供热技术发展现状及展望

介绍了国内外生物质户用供热产业、技术的发展现状,分析了国外应用比较广泛的生物质供热设备的特点以及生物质和太阳能联合供热系统,指出了生物质供热技术存在的主要问题,并提出我国生物质户用供热技术的发展方向,发展生物质户用供热技术将有效地缓解由农村传统供热带来的资源环境问题,具有良好的环境、经济和社会效益。