A review of thermal-chemical conversion of lignocellulosic biomass in China

Biomass, a renewable, sustainable and carbon dioxide neutral resource, has received widespread attention in the energy market as an alternative to fossil fuels. Thermal-chemical conversion of biomass to produce biofuels is a promising technology with many commercial applications. This paper reviewed the state-of-the-art research and development of thermal-chemical conversion of biomass in China with a special focus on gasification, pyrolysis, and catalytic transformation technologies. The advantages and disadvantages, potential of future applications, and challenges related to these technologies are discussed. Conclusively, these transformation technologies for the second-generation biofuels with using non-edible lignocellulosic biomass as feedstocks show prosperous perspective for commercial applications in near future.     

Advances in thermochemical conversion of woody biomass to energy,fuels and chemicals

Biomass has been recognised as a promising resource for future energy and fuels. The biomass, originated from plants, is renewable and application of its derived energy and fuels is close to carbon-neutral by considering that the growing plants absorb CO₂ for photosynthesis. However, the complex physical structure and chemical composition of the biomass significantly hinder its conversion to gaseous and liquid fuels.This paper reviews recent advances in biomass thermochemical conversion technologies for energy, liquid fuels and chemicals. Combustion process produces heat or heat and power from the biomass through oxidation reactions; however, this is a mature technology and has been successfully applied in industry. Therefore, this review will focus on the remaining three thermochemical processes, namely biomass pyrolysis, biomass thermal liquefaction and biomass gasification. For biomass pyrolysis, biomass pretreatment and application of catalysts can simplify the bio-oil composition and retain high yield. In biomass liquefaction, application of appropriate solvents and catalysts improves the liquid product quality and yield. Gaseous product from biomass gasification is relatively simple and can be further processed for useful products. Dual fluidised bed (DFB) gasification technology using steam as gasification agent provides an opportunity for achieving high hydrogen content and CO₂ capture with application of appropriate catalytic bed materials. In addition, multi-staged gasification technology, and integrated biomass pyrolysis and gasification as well as gasification for poly-generation have attracted increasing attention.     

Energy production from biomass (Part 3): Gasification technologies

The conversion of biomass by gasification into a fuel suitable for use in a gas engine increases greatly the potential usefulness of biomass as a renewable resource. Gasification is a robust proven technology that can be operated either as a simple, low technology system based on a fixed-bed gasifier, or as a more sophisticated system using fluidized-bed technology. The properties of the biomass feedstock and its preparation are key design parameters when selecting the gasifier system. Electricity generation using a gas engine operating on gas produced by the gasification of biomass is applicable equally to both the developed world (as a means of reducing greenhouse gas emissions by replacing fossil fuel) and to the developing world (by providing electricity in rural areas derived from traditional biomass).     

Biomass gasification in India — DNES activities

Gasification of biomass, which includes a series of interlinked thermochemical processes like pyrolysis and gasoline refining, offers a promising scope to meet energy needs both for stationary and mobile purposes. The present communication is aimed at discussing the gasification programme in India with particular reference to the following five main areas: R& D, pilot-testing and evaluation including prototype production, demonstrative application and evaluation of biomass gasification, training and manpower development, commercialisation and manufacture development. Emphasis is laid upon the need to integrate energy plantation on sub-standard soils with biomass gasification.     

Charge Pumping Strategy for Rotation and Sliding Type Triboelectric Nanogenerators

Triboelectric nanogenerator (TENG) is an emerging approach for harvesting energy from the living environment. But its performance is limited by the maximum density of surface charges created by contact electrification. Here, by rationally designing a synchronous rotation structure, a charge pumping strategy is realized for the first time in a rotary sliding TENGs, which is demonstrated to enhance the charge density by a factor of 9, setting up a record for rotary TENGs. The average power is boosted by more than 15 times compared with normal TENGs, achieving an ultrahigh average power density of 1.66 kW m^?3, under a low drive frequency of 2 Hz. Moreover, the charge pumping mechanism enables decoupling of bound charge generation and the severity of interfacial friction in the main TENG, allowing surface lubricants to be applied for suppressing abrasion and lowering heat generation. The adaptability of the strategy to rotation and sliding type TENGs in low‐frequency agitations provides a breakthrough to the bottleneck of power output for mechanical energy harvesting, and should have a great impact on high‐power TENG design and practical applications in various fields.     

An economic analysis of biomass gasification and power generation in China

With vast territory and abundant biomass resources China appears to have suitable conditions to develop biomass utilization technologies. As an important decentralized power technology, biomass gasification and power generation (BGPG) has a potential market in making use of biomass wastes. In spite of the relatively high cost for controlling secondary pollution by wastewater, BGPG is economically feasible and can give a financial return owing to the low price of biomass wastes and insufficient power supply at present in some regions of China. In this work, experimental data from 1 MW-scale circulating fluidized bed (CFB) BGPG plants constructed recently in China were analyzed; and it was found that the unit capital cost of BGPG is only 60-70% of coal power station and its operation cost is much lower than that of conventional power plants. However, due to the relatively low efficiency of small-scale plant, the current BGPG technology will lose its economic attraction when its capacity is smaller than 160 kW or the price of biomass is higher than 200 Yuan RMB/ton. The development of medium-scale BGPG plants, with capacity ranging from 1000 to 5000 kW, is recommended; as is the demonstration of BGPG technology in suitable enterprises (e.g. rice mill and timber mill) in developing countries where large amounts of biomass wastes are available so that biomass collection and transportation can be avoided and the operation cost can be lowered.     

Artificial, non-antibody binding proteins for pharmaceutical and industrial applications

Using combinatorial chemistry to generate novel binding molecules based on protein frameworks ('scaffolds') is a concept that has been strongly promoted during the past five years in both academia and industry. Non-antibody recognition proteins derive from different structural families and mimic the binding principle of immunoglobulins to varying degrees. In addition to the specific binding of a pre-defined target, these proteins provide favourable characteristics such as robustness, ease of modification and cost-efficient production. The broad spectrum of potential applications, including research tools, separomics, diagnostics and therapy, has led to the commercial exploitation of this technology by various small- and medium-sized companies. It is predicted that scaffold-based affinity reagents will broaden and complement applications that are presently covered by natural or recombinant antibodies. Here, we provide an overview on current approaches in the biotech industry, considering both scientific and commercial aspects.     

Development of a high-temperature air-blown gasification system

Current status of high-temperature air-blown gasification technology development is reviewed. This advanced gasification system utilizes preheated air to convert coal and waste-derived fuels into synthetic fuel gas and value-added byproducts. A series of demonstrated, independent technologies are combined to form the core of this gasification system. A high-temperature, rapid devolatilization process is used to enhance the volatile yields from the fuel and to improve the gasification efficiency. A high-temperature pebble bed filter is used to remove to the slag and particulates from the synthetic fuel gas. Finally, a novel regenerative heater is used to supply the high-temperature air for the gasifier. Component development tests have shown that higher gasification efficiencies can be obtained at more fuel-rich operating conditions when high-temperature air is used as the gasification agent. Test results also demonstrated the flex-fuel capabilities of the gasifier design. Potential uses of this technology range from large-scale integrated gasification power plants to small-scale waste-to-energy applications.     

Forest tree fertilization with sewage

While requirements for industrial and fuel woods are increasing in India, the area of forest land is actually decreasing. Measures for meeting the long term requirements of the country in respect of forest produce and its economic and efficient exploitation on a large scale have been initiated by the Government through its numerous afforestation programmes. The primary requisite for a successful plantation programme is raising of planting stock in the nursery.

Thus the exploitation of the resources in wastewater through recycling and reuse via the growth of forest tree seedlings could become a viable waste-management practice. A study was conducted to assess the early growth-response of some important forest-tree species to sewage and sludge applications. The results showed that the wastes had generally favourable effects on the germination and early seedling growth of forest-tree species.     

Fluidized-bed steam gasification of rice hull

Steam gasification of grain by-products can be a significant biomass conversion technology because of the need to utilize agricultural waste for non-food applications including energy resources. The most obvious beneficiary will be the developing countries whose economies are often tied to agricultural produce and are lacking in conventional fuels. One agricultural by-product that shows promise is the rice hull; it is found in abundance in the rice mills of producer countries and is considered as a waste material. Although gasification of rice hull has been proposed as a potential waste disposal and energy recovery method, little has been done to fully realize this proposition. In the present work, data were obtained for steam gasification of rice hull in a bench-scale fluidized-bed gasifier, a technology which has proven to be feasible for other grain by-products. The produced gas, which is rich in hydrogen, has been found to have a heating value ranging between 12.1 and 11.1 MJ m⁻³ at the respective reactor temperatures of 700 and 800°C; energy recovery varies between 35 and 59%.     

The exploitation argument against commercial surrogacy

This paper discusses the exploitation argument against commercial surrogacy: the claim that commercial surrogacy is morally objectionable because it is exploitative. The following questions are addressed. First, what exactly does the exploitation argument amount to? Second, is commercial surrogacy in fact exploitative? Third, if it were exploitative, would this provide a sufficient reason to prohibit (or otherwise legislatively discourage) it? The focus throughout is on the exploitation of paid surrogates, although it is noted that other parties (e.g. ‘commissioning parents’) may also be the victims of exploitation. It is argued that there are good reasons for believing that commercial surrogacy is often exploitative. However, even if we accept this, the exploitation argument for prohibiting (or otherwise legislatively discouraging) commercial surrogacy remains quite weak. One reason for this is that prohibition may well ‘backfire’ and lead to potential surrogates having to do other things that are more exploitative and/or more harmful than paid surrogacy. It is concluded therefore that those who oppose exploitation should (rather than attempting to stop particular practices like commercial surrogacy) concentrate on: (a) improving the conditions under which paid surrogates ‘work’; and (b) changing the background conditions (in particular, the unequal distribution of power and wealth) which generate exploitative relationships.     

Application of a conventional fishery model for assessment of entrainment and impingement impact

Synopsis A conventional stock assessment model is applied to determine the impact of entrainment and impingement at the Monroe Power Plant on the yellow perch stock of the Western basin of Lake Erie. Parameters of the model are estimated using power plant data, biological data available in the literature, and commercial catch data. The model is applied to estimate the age structure and biomass of the perch stock and to estimate the impact of the power plant on abundance of the impingeable stock and abundance and biomass of the exploited stock. The level of impact was examined under a range of mortality conditions. Under the most extreme conditions examined of full pumping, high fishing mortality, and low natural mortality, the fishable biomass is reduced by 1.7%. This impact is not large, but there are several other power plants and many additional water intakes around the Western basin of Lake Erie.     

Economic analysis of biomass power generation schemes under renewable energy initiative with Renewable Portfolio Standards (RPS) in Korea

An economic analysis of biomass power generation was conducted. Two key technologies--direct combustion with a steam turbine and gasification with a syngas engine--were mainly examined. In view of the present domestic biomass infrastructure of Korea, a small and distributed power generation system ranging from 0.5 to 5 MW(e) was considered. It was found that gasification with a syngas engine becomes more economically feasible as the plant size decreases. Changes in the economic feasibilities with and without RPS or heat sales were also investigated. A sensitivity analysis of each system was conducted for representative parameters. Regarding the cost of electricity generation, electrical efficiency and fuel cost significantly affect both direct combustion and gasification systems. Regarding the internal rate of return (IRR), the heat sales price becomes important for obtaining a higher IRR, followed by power generation capacity and electrical efficiency.     

Biomass gasification: Development cooperation in Belgium

Development cooperation in the field of biomass gasification between Belgium and the Developing Countries, Indonesia and Zaire is discussed. Results from the fluidized-bed gasification of Eucalyptus deglupta wood in Indonesia and the testing of a moving-bed gasifier in a remote location in Zaire are presented. The impact of these technologies on the rural communities is analyzed.     

生物质气化制取代用天然气的模拟

介绍了生物质气化制取代用天然气的技术,并利用Aspen Plus软件建立了串行流化床生物质气化制取代用天然气的模型,并对整个流程进行模拟。着重研究了气化过程中操作参数(气化温度Tg、S/B)对甲烷化反应过程主要指标(包括甲烷产率、碳转化率等)的影响。研究结果表明提高气化温度和S/B有利于提高气化产物中生物质合成气的浓度,并得到较高氢碳比的合成气,从而可以提高甲烷的产率和整个系统的碳转化率;为获得较高的甲烷产率和碳转化率,适宜的气化温度为700～750℃,S/B值在0.4左右。     

Effects of Irrigation and Nitrogen on the Performance of Aerobic Rice in Northern China

Aerobic rice is a new production system in which specially-developed varieties are grown under non-flooded, non-puddled, and non-saturated soil conditions. In 2003-2004, irrigation x Nitrogen experiments were carried out near Beijing using variety HD297. Water treatments included four irrigation levels, and Nitrogen treatments included different fertilizer N application rates and different numbers of N splits. The highest yields were 4460 kg/ha with 688 mm of total (rain plus irrigation) water input in 2003 and 6 026 kg/ha with 705 mm of water input in 2004. Because of the quite even distribution of rainfall in both years, the four irrigation treatments did not result in large differences of soil water conditions. There were few significant effects of irrigation on biomass accumulation, but yield increased with the total amount of water applied. High yields coincided with high harvest index and high percentages of grain filling. The application of fertilizer N either reduced biomass and yield or kept it at the same level as 0 N and consistently reduced the percentage grain filling and 1 000-grain weight. With the highest water application, five splits of N gave higher yield than three splits, whereas three splits gave higher yield than five splits with lower water applications.     

Natural Leaf Made Triboelectric Nanogenerator for Harvesting Environmental Mechanical Energy

Distributed environmental mechanical energy is rarely collected due to its fluctuating amplitudes and low frequency, which is usually attributed as “random” energy. Considering the rapid development of the Internet of things (IoT), there is a great need for a large number of distributed and sustainable power sources. Here, a natural leaf assembled triboelectric nanogenerator (Leaf‐TENG) is designed by utilizing the green leaf as an electrification layer and electrode to effectively harvest environmental mechanical energy. The Leaf‐TENG with good adaptability has the maximum output power of ≈45 mW m^?2, which is capable of driving advertising LEDs and commercial electronic temperature sensors. Besides, a tree‐shaped energy harvester is integrated with natural Leaf‐TENG to harvest large‐area environmental mechanical energy. This work provides a new prospect for distributed and environmental‐friendly power sources and has potential applications in the IoT and self‐powered systems.     

The Origin of the USDA Regional Biomass Research Centers

The U.S. Department of Agriculture (USDA) Regional Biomass Research Centers (RBRC) were created to contribute to the planning, research, and development of entire long-term sustainable biofuel production supply chains based on agricultural and forest-based feedstocks. The intent of the centers is to provide a catalyst that links feedstock genetic development, sustainable production and management, logistics, conversion, co-product production, distribution, and market demand suited to the available economic, social, and natural resources within different regions. The centers provide a coordinated, region-based research focus designed with relatively short-term deliverables to help accelerate the commercial production of biomass and other biofuel feedstocks. The centers provide a leadership structure for coordinating biomass research across the country, providing a national perspective that complements other USDA agency efforts designed to help US rural communities participate in the emerging biofuels and biobased products economy. Through coordination with the RBRC, USDA research and service agency programs and resources have been leveraged with the U.S. Department of Energy (DOE) and other federal department, university, and private industry efforts to help accelerate commercial advancement of advanced biofuel production to promote rural economic opportunities and achieve transportation biofuel policy goals.     

Simulation of biomass gasification with a hybrid neural network model

Gasification of several types of biomass has been conducted in a fluidized bed gasifier at atmospheric pressure with steam as the fluidizing medium. In order to obtain the gasification profiles for each type of biomass, an artificial neural network model has been developed to simulate this gasification processes. Model-predicted gas production rates in this biomass gasification processes were consistent with the experimental data. Therefore, the gasification profiles generated by neural networks are considered to have properly reflected the real gasification process of a biomass. Gasification profiles identified by neural network suggest that gasification behavior of arboreal types of biomass is significantly different from that of herbaceous ones.     

Microbial amelioration of crop salinity stress

The use of soil and irrigation water with a high content of soluble salts is a major limiting factor for crop productivity in the semi-arid areas of the world. While important physiological insights about the mechanisms of salt tolerance in plants have been gained, the transfer of such knowledge into crop improvement has been limited. The identification and exploitation of soil microorganisms (especially rhizosphere bacteria and mycorrhizal fungi) that interact with plants by alleviating stress opens new alternatives for a pyramiding strategy against salinity, as well as new approaches to discover new mechanisms involved in stress tolerance. Although these mechanisms are not always well understood, beneficial physiological effects include improved nutrient and water uptake, growth promotion, and alteration of plant hormonal status and metabolism. This review aims to evaluate the beneficial effects of soil biota on the plant response to saline stress, with special reference to phytohormonal signalling mechanisms that interact with key physiological processes to improve plant tolerance to the osmotic and toxic components of salinity. Improved plant nutrition is a quite general beneficial effect and may contribute to the maintenance of homeostasis of toxic ions under saline stress. Furthermore, alteration of crop hormonal status to decrease evolution of the growth-retarding and senescence-inducing hormone ethylene (or its precursor 1-aminocyclopropane-1-carboxylic acid), or to maintain source-sink relations, photosynthesis, and biomass production and allocation (by altering indole-3-acetic acid and cytokinin biosynthesis) seem to be promising target processes for soil biota-improved crop salt tolerance.