武汉市造纸行业资源代谢分析

资源代谢问题是造成产业系统生态环境影响的主要原因.在分析武汉市造纸行业资源代谢的基础上从资源输入-资源使用-环境胁迫-系统循环共生4个方面构建武汉市造纸行业资源代谢分析指标体系.运用模糊综合评判法和问题树模型对2007年武汉市造纸业的原材料、水、能源等资源的代谢与全国造纸行业平均水平进行了比较分析.结果表明:(1)武汉市造纸业资源代谢水平总体上评价等级为优,但某些指标与全国平均水平比还略有差距;(2)从资源输入角度分析,原材料输入生态效率及水资源输入生态效率等级为优,能源输入生态效率等级为良;(3)从资源使用角度分析,单位产品的原材料消耗及单位产品的水资源消耗等级为优,单位产品的能源消耗等级为良;(4)从环境胁迫角度分析,单位污染物工业总产值及单位产品污染物排放等级均为优,污染物达标排放率等级为良;(5)从系统循环共生分析,企业清洁生产达标率等级为良,资源持续利用及污染物治理等级为优,而中水回用率等级为差.通过代谢分析可得,武汉市造纸行业能源输入生态效率、单位产品能源消耗与全国平均水平比还有一定距离,整个行业中企业清洁生产比例还具有提升的空间;中水回用方面较弱,需要特别加强.     

Materials and Energy Flow Analysis of Paper Consumption in the United Kingdom, 1987-2010

This article presents the results of a life-cycle materials and energy flow analysis for the pulp and paper cycle in the United Kingdom. Material flows are reconstructed for the period be-tween 1987 and 1996 for all major processes associated with the paper cycle, and system energy requirements are calculated over this period using the best available data. Attention is drawn to the import dependence of U.K. paper demand, and the significant energy requirements associated with upstream forestry processes. The historical trend analysis is then used to model possible future developments in materials and energy consumption until 2010 under a variety of assumptions about process technology improvements, wastepaper utilization rates, and changing demand trends. The results indicate that policy options to increase recycling yield some energy benefits, but these are small by comparison with the benefits to be gained by reducing consumption of paper and improving process technology. The structure of the electricity supply industry in the United Kingdom means that global energy benefits could also be achieved by increasing the contribution from imported pulp.     

Environmental impacts of forest production and supply of pulpwood: Spanish and Swedish case studies

Background, aim and scope  Forest operations use large amounts of energy, which must be considered when life cycle assessment (LCA) methodology is applied to forest products. Forest management practices differ considerably between countries and may also differ within a country. This paper aims to identify and compare the environmental burdens from forest operations in Sweden and Spain focused on pulpwood production and supply to pulp mills. Materials and methods  To perform the analysis, the main forest plantations were investigated as well as the most important tree species used in pulp mills in both countries: eucalyptus and, Norway spruce and Scots pine, were taken into account for the Spanish and Swedish case studies, respectively. Energy requirements for pulpwood production and supply to Spanish and Swedish pulp mills are evaluated in this paper. All forest operations from site preparation to extraction of felled wood to the delivery point at the roadside are included within the system boundaries as well as wood transport from forest landing to the pulp mill gate. Seedling and machinery production are excluded from the system boundaries due to lack of field data. The impact assessment phase was carried out according to the Swedish Environmental Management Council and, in particular, the impact categories assessed in forest and agricultural LCAs (global warming, acidification, eutrophication and photochemical oxidant formation) were analysed. SimaPro 7.10 software was used to perform the impact assessment stage. Results  Different types of wood are produced in both case studies: softwood in Sweden and hardwood in Spain, with higher production of round wood and biomass per hectare in Sweden. Total energy use for pulpwood production and supply are in a similar order of magnitude, up to 395 MJ and 370 MJ/m³ solid under bark in Spain and Sweden, respectively. Field operations, such as silviculture and logging, are more energy-intensive in the Spanish case study. However, secondary hauling of pulpwood to pulp mill requires more energy in the Swedish case study. These important differences are related to different forest management practices as well as to pulpwood supply to the pulp mill. The eventual imports of pulpwood, application of pesticides, thinning step or final felling considerably affects energy requirements, which are reflected on the environmental results. Discussion  Although differences between both case studies were observed, several stages were investigated: wood delivery to the pulp mill by road, harvesting and forwarding, contribute considerably to acidification, eutrophication and global warming potential in both cases. The type of wood, the machines used in forest operations (mechanised or motor-manual), the use of fossil fuels and the amount of wood produced influence the results. These differences must be kept in mind in comparative studies between such different countries. Conclusions  The results obtained in this work allow one to forecast the importance of forest operations in LCA of forest products (in this case, wood pulp) and the influence of energy use in the results. Special attention has been paid in the inventory analysis stage for both case studies. It is possible to gain a better environmental performance in both case studies if alternative practices are considered, mainly focused on site preparation and stand tending in the Spanish system and on pulpwood supply in the Swedish one. Recommendations and perspectives  This study provides useful information that can assist forest-based industries in the aim of increasing their sustainability. Future work will focus on the study of several transport alternatives of pulpwood supply including railway, road and ship. In addition, pulpwood processing in Spanish and Swedish paper pulp mills considered to be representative of the “state of art” will be carried out in order to get a complete picture of this kind of forest-based industry. In addition, the use of biofuels (such as forest biomass) instead of fossil fuels and CO₂ uptake of wood via photosynthesis will be carried out in order to have a complete perspective of forest ecosystems.     

Life cycle assessment of printing and writing paper produced in Portugal

Goal, Scope and Background The environmental sustainability is one of the current priorities of the Portuguese pulp and paper industry. Life Cycle Assessment (LCA) was the methodology chosen to evaluate the sustainability of the printing and writing paper production activity. This paper grade represents about 60% of the total production of paper in Portugal and its production is expected to increase in the near future. The main goal of this study was to assess the potential environmental impacts associated with the entire life cycle of the printing and writing paper produced in Portugal from Eucalyptus globulus pulp and consumed in Germany, in order to identify the processes with the largest environmental impacts. Another goal of this study was to evaluate the effect on the potential environmental impacts of changing the market where the Portuguese printing and writing paper is consumed: German market vs. Portuguese market. Methods The main stages considered in this study were: forestry, pulp production, paper production, paper distribution, and paper final disposal. Transports and production of chemicals, fuels and energy in the grid were also included in these stages. Whenever possible and feasible, average or typical data from industry were collected. The remaining data were obtained from the literature and specialised databases. A quantitative impact assessment was performed for five impact categories: global warming over 100 years, acidification, eutrophication, non-renewable resource depletion and photochemical oxidant formation. Results In the German market scenario, the paper production stage was a remarkable hot spot for air emissions (non-renewable CO₂, NO_x and SO₂) and for non-renewable energy consumption, and, consequently, for the impact categories that consider these parameters: global warming, acidification and non-renewable resource depletion. These important environmental impacts are due to the energy requirements in the printing and writing paper production process, which are fulfilled by on-site fuel oil burning and consumption of electricity from the national grid, which is mostly based on the use of fossil fuels. The pulp production stage was identified as the largest contributor to water emissions (COD and AOX) and to eutrophication. Considering that energy consumed by the pulp production processes comes from renewable fuels, this stage was also the most contributing to renewable energy consumption. Discussion The paper distribution stage showed an important contribution to NO_x emissions, which, however, did not result in a major contribution to acidification or eutrophication. The final disposal stage was the main contributor to the photochemical oxidant formation potential due to CH₄ emissions from wastepaper landfilling. On the other hand, paper consumption in Portugal was environmentally more favourable than in Germany for the parameters/impact categories where the paper distribution stage has a significant contribution (non-renewable CO₂, NO_x, non-renewable energy consumption, acidification, eutrophication and non-renewable resource depletion) due to shorter distances needed to deliver paper to the consumers. For the remaining parameters/impact categories, the increase observed in the final disposal stage in the Portuguese market was preponderant, and resulted from the existence of significant differences in the final disposal alternatives in the analysed markets (recycling dominates in Germany, whereas landfilling dominates in Portugal). Conclusions The pulp and paper production stages were found to be of significance for almost all of the inventory parameters as well as for the impact assessment categories. The paper distribution and the final disposal stages were only of importance for some of the inventory parameters and some of the impact categories. The forestry stage played a minor role in the environmental impacts generated during the paper life cycle. The consumption of paper in Portugal led to a decrease in the environmental burdens of the paper distribution stage, but to an increase in the environmental burdens of the final disposal stage, when compared with the consumption of paper in Germany. Recommendations and Perspectives This study provides useful information that can assist the pulp and paper industry in the planning of future investments leading to an increase in its sustainability. The results of inventory analysis and impact assessment show the processes that play an important role in each impact category, which allow the industry to improve its environmental performance, making changes not only in the production process itself, but also in the treatment of flue gases and liquid effluents. Besides that concern regarding pollution prevention, other issues with relevance to the context of sustainability, such as the energy consumption, can also be dealt with.     

Triple bottom line study of a lignocellulosic biofuel industry

Growing concerns about energy security and climate change have prompted interest in Australia and worldwide to look for alternatives of fossil fuels. Among the renewable fuel sources, biofuels are one such alternative that have received unprecedented attention in the past decade. Cellulosic biofuels, derived from agricultural and wood biomass, could potentially increase Australia's oil self‐sufficiency. In this study, we carry out a hybrid life‐cycle assessment (LCA) of a future cellulose‐refining industry located in the Green Triangle region of South Australia. We assess both the upstream and downstream refining stages, and consider as well the life‐cycle effects occurring in conventional industries displaced by the proposed biofuel supply chains. We improve on conventional LCA method by utilising multi‐region input–output (IO) analysis that allows a comprehensive appraisal of the industry's supply chains. Using IO‐based hybrid LCA, we evaluate the social, economic and environmental impacts of lignocellulosic biofuel production. In particular, we evaluate the employment, economic stimulus, energy consumption and greenhouse gas impacts of the biofuel supply chain and also quantify the loss in economic activity and employment in the paper, pulp and paperboard industry resulting from the diversion of forestry biomass to biofuel production. Our results reveal that the loss in economic activity and employment will only account for 10% of the new jobs and additional stimulus generated in the economy. Lignocellulosic biofuel production will create significant new jobs and enhance productivity and economic growth by initiating the growth of new industries in the economy. The energy return on investment for cellulosic biofuel production lies between 2.7 and 5.2, depending on the type of forestry feedstock and the travel distance between the feedstock industry and the cellulose refinery. Furthermore, the biofuel industry will be a net carbon sequester.     

Valorisation of wastepaper using the fibrolytic/hydrogen producing bacterium Ruminococcus albus

The present study aimed to investigate the biotransformation of different kinds of wastepaper to hydrogen by the fibrotylic bacterium Ruminococcus albus. Five different types i.e. paper tissue, office paper, illustrated magazine paper, paperboard and newspaper, were selected as representatives of the most common types of wastepaper found in municipal solid wastes. The percentage of total carbohydrates measured as glucose equivalents, ranged from 50% to 100% (w/w), whereas the bioconversion by R. albus ranged from 18% to 100% of their initial weigh. The only metabolic products detected in all cases were acetate, ethanol, formate, hydrogen and carbon dioxide. The hydrogen yields ranged from 46 to 280 L H₂/kg paper, indicating that wastepaper could be a promising candidate for second generation biohydrogen production. Subsequently, hydrolysis was investigated for paper tissue and paperboard. It was shown that in both cases the degradation process could be satisfactory described by zero order kinetics and it was identified to be the rate limiting step for the whole process, controlling biomass growth and metabolites generation rate.     

Pulp Nonfiction: Regionalized Dynamic Model of the U.S. Pulp and Paper Industry

This article presents a modeling framework that enhances our ability to analyze the implications of policy for future sustainability of industrial systems. The framework quantifies the relationship between physical input and waste flows, capital vintage, and investment behavior in the U.S. pulp and paper industry. A regional vintage model is developed that simultaneously incorporates investment decisions, vintage structure of the capital stock, and physical material and energy flows, in addition to paper demand. Each capital vintage is specified by size, output structure, and age-specific retirement rates, as well as fiber use and energy intensities. Both embodied and disembodied technological change are incorporated, as well as greenhouse gas emissions from fuel use, and decomposition and incineration of waste. Estimated equations are used to simulate industrial futures until 2020, from a system of nonlinear differential equations.
Our results demonstrate the economic and physical inter-dependence between material and energy flows and the central role energy prices have in decision-making. For instance, an increase in average energy prices, ceteris paribus , will on average discourage paper recycling, which has implications for greenhouse gas emissions as well as for changes in energy intensity. The analysis of the data reveals diminishing rates of energy self-generation, and the immense longevity of capital, which hampers rapid change in input and carbon intensity. This stresses the importance of investment-led strategies in facilitating faster capital turnover to enhance future sustainability of the system.     

The climate change implications of offshoring Finnish pulp production to South America

Purpose  

Offshoring of pulpwood production outside Europe is more and more common, which increases transport distances and also changes production technologies, raw material supply and energy production profiles. In this paper, we aim to compare the life cycle greenhouse gas emissions of pulp production from Finnish boreal hardwood and from South American eucalyptus. Special emphasis was placed on analysing the contribution of transport to overall climate impacts.     

Anthropogenic Carbon Stock Dynamics of Pulp and Paper Products in Germany

Carbon‐based materials (CBMs) for energetic and material purposes combine biogenic and anthropogenic carbon cycles. In the latter, numerous manufactured products with various in‐use lifespans accumulate as anthropogenic carbon stocks. Understanding the behavior of these stocks is an important requirement to estimate not only future waste amounts, source for secondary raw materials, but also the impacts and effects in carbon emissions and carbon management. Previous models have estimated material stock changes; however, a lack of research in carbon stocks is perceived. Moreover, studies follow in‐use lifespan estimation approaches, such as decay functions, which do not coincide with observed consumption and waste treatment patterns. In the first part of this article, we present a carbon stock‐flow model to analyze inter‐relationships between carbon flows and stocks from raw materials to waste treatment processes considering a consumer perspective, where the dynamics of anthropogenic carbon stocks are completely described. In the second part, we study the pulp and paper industry in Germany under a scenario approach to analyze the behavior, development, and impacts of paper stocks and flows between 2010 and 2040. The model provided coherent results, with industrial data estimating 33.9 million metric tons in 2010 in paper stocks, equivalent to 410 kilograms per person. Consumption per capita and in‐use lifespan of products were identified as the most significant variables in carbon stock building. Model simulations show a sustained growth in stocks for the next 30 years, with increase in waste and carbon emissions. But in combination with recycling and reuse mechanisms and consumption patterns, environmental impacts are reduced.     

U.S. Federal Initiatives to Support Biomass Research and Development

This article provides a brief overview of federal initiatives in the United States to support biomass research, demonstration, and development. The interest in the biomass industry and U.S. federal efforts to spur development of, increased production of, and use of biopower, biofuels, and biobased products, collectively known as the "biomass industry", are discussed. A growing level of leadership from the executive branch of the federal government and support by the U.S. Congress are documented. Five important policy drivers that support this heightened emphasis on biomass for power, fuels, and products are identified and discussed. The current status of U.S. dependence on these renewable energy sources is briefly outlined. Federal biomass funding activity for the current fiscal year by the U.S. Department of Agriculture and the U.S. Department of Energy, two major federal participants in research, demonstration, and development for this industry, is briefly outlined. This funding commitment is placed into an overall context of total federal support for all research and development. Finally, the article suggests future market penetration targets for this industry, emphasizes the importance of infrastructure development necessary to support the industry's growth, and notes the payoff from such development for farmers, foresters, rural communities, and the environment.     

Decomposition Analysis of Finnish Material Flows: 1960–1996

To the extent that environmental impacts are the consequence of the magnitude of total material input into production in an economy, they can be lessened by reducing the use of materials—by concentrating on what has been called qualitative growth. This article presents a summary of Finnish resource use over the period 1960–1996 as a means of evaluating the trends in material use and providing a basis for assessments of sustainability. It adapts the technique of decomposition analysis developed in the field of energy studies to distinguish the effects of changes in aggregate economic activity ("activity effect"), composition of industrial activity ("structural effect") and materials intensity of use ("intensity effect") on a sectoral basis.p
According to the analysis presented here, materials consumption in Finland has grown substantially between 1960 and 1996 in the electricity, gas and water supply, pulp and paper production, civil engineering, and mining and quarrying sectors. In the same period, the ratio of GDP/mass of material mobilized has improved by 175 percent. Economic growth has caused the largest increases in materials use in the building of infrastructures; for example roads, waterways, means of supplying electricity, gas, and water, and in the production of paper and paper products. The least growth took place in the transport, basic metals production, and mining and quarrying sectors.     

辽宁省能源消费与经济增长的灰色关联

我国能源消费与经济增长的矛盾日益突出.辽宁省是我国重工业基地和能源消耗大省,经济发展对能源依赖性强,能源供不应求的状态日益显著.为了深入了解辽宁省能源消费与经济增长的关系,提出科学的低碳发展建议,本文基于2000—2012年辽宁省能源消费与经济增长相关数据,应用灰色关联分析,分别对辽宁省能源消费产业和能源消费品种与经济增长的相关性进行实证分析.结果表明: 在各产业能源消费中,批发零售业和住宿餐饮业能源消费量很少,但与经济增长的关联程度最大,工业消费量最大,却与经济增长的关联度较弱;在能源消费品种中,石油和水电能源消费量与经济增长的灰色关联度显著,但煤炭能源消费量与经济增长的关联度不显著,表明煤炭的利用效率低.为实现低碳可持续发展,辽宁省应转变经济增长方式、调整产业结构、优化能源结构、提高能源利用效率,特别是应大力发展生产性服务业,推进清洁能源和可再生能源的开发.     

Environmental Assessment of Wood‐Based Biofuel Production and Consumption Scenarios in Norway

In Norway, the boreal forest offers a considerable resource base, and emerging technologies may soon make it commercially viable to convert these resources into low‐carbon biofuels. Decision makers are required to make informed decisions about the environmental implications of wood biofuels today that will affect the medium‐ and long‐term development of a wood‐based biofuels industry in Norway. We first assess the national forest‐derived resource base for use in biofuel production. A set of biomass conversion technologies is then chosen and evaluated for scenarios addressing biofuel production and consumption by select industry sectors. We then apply an environmentally extended, mixed‐unit, two‐region input?output model to quantify the global warming mitigation and fossil fuel displacement potentials of two biofuel production and consumption scenarios in Norway up to 2050. We find that a growing resource base, when used to produce advanced biofuels, results in cumulative global warming mitigation potentials of between 58 and 83 megatonnes of carbon dioxide equivalents avoided (Mt‐CO₂‐eq.‐avoided) in Norway, depending on the biofuel scenario. In recent years, however, the domestic pulp and paper industry—due to increasing exposure to international competition, capacity reductions, and increasing production costs—has been in decline. In the face of a declining domestic pulp and paper industry, imported pulp and paper products are required to maintain the demand for these goods and thus the greenhouse gas (GHG) emissions of the exporting region embodied in Norway's pulp and paper imports reduce the systemwide benefit in terms of avoided greenhouse gas emissions by 27%.     

辽宁省能源消费和碳排放与经济增长的关系

在广泛收集资料的基础上,对辽宁省的能源利用效率、能源消费强度与经济增长的关系进行探索,其目的为辽宁省的节能与CO2减排及经济的快速发展提供科学依据。结果表明:辽宁整体单位GDP能耗高出全国水平52%—70%,第二产业单位GDP能耗是第三产业的5.67—8.41倍,第一产业的7.2—9.0倍;辽宁能源利用率只有全国平均水平的60%左右,第二产业能源利用效率只有第一产业的11.89%,第三产业的12.60%;GDP年增长速率大于能源消费量年增长速率,能源投入增加促进了国民生产总值的提高,但是经济增长并不是完全依赖能源消费的增长;能源消费量与经济增长的关系,呈现出"N型"曲线特征,随着GDP的增加,能源消费量出现反复上升和下降过程,辽宁省能源消费和经济增长关系没有达到长期的均衡性,尚处于非平衡的发展阶段。     

长白山次生针阔混交林叶凋落物中有机物分解与碳、氮和磷释放的关系

采用分解袋法,研究了长白山次生针阔混交林内9种树种叶凋落物34个月的分解过程.结果表明:在次生针阔混交林中,不同树种叶凋落物的初始N和P浓度存在很大差异,叶凋落物分解速率(k)与初始N浓度和C/N显著相关.有机物剩余百分率与C剩余百分率呈显著的线性正相关关系,与N和P剩余百分率之间呈显著的二项式回归关系. N和P剩余百分率在初期阶段随有机物分解而增加,达到峰值后逐渐降低. 随着有机物剩余百分率的下降,C/N和C/P均呈逐渐降低趋势,各种叶凋落物之间C/N和C/P的差异逐渐减小,分解末期分别趋近于23和350. 随有机物剩余百分率的降低, N/P变化不明显,当有机物剩余百分率低于25%时,不同树种叶凋落物之间N/P差异显著下降. 有机物剩余百分率可用来预测C、N和P的剩余百分率.      

An integrative and prospective approach to regional material flow analysis: Modeling the decarbonization of the North Rhine-Westphalian steel industry

North-Rhine Westphalia is the center of the German and European steel production. Its steel industry is heavily based on the primary production route and emits up to 30 Mt CO₂ annually. One possible and increasingly prominent alternative to reduce these emissions is the hydrogen-based direct reduction. While this technology allows for a near climate-neutral production of primary steel, it poses substantial impacts on regional energy and material flows. Hence, the aim of this paper is to quantify the alterations in energy and material flows over time via integrating top-down energy and material flow models with bottom-up process models. The resulting values of emissions, energy, and material flows are then used to develop prospective scenarios that depict the requirements and consequences of potential pathways toward a climate-neutral steel production by 2045. The outcomes show that decarbonizing the North Rhine-Westphalian steel industry leads to an additional demand for renewable energies of up to 52.5 TWh per year, which represents 10% of the current electricity production in Germany. As securing the green electricity demand is a large challenge, the study also analyzes the impact of a partial recourse to natural gas as a reducing agent in combination with other measures like carbon capture and utilization/storage. The results show that such a recourse would reduce the electricity demand to 36.8 TWh. Hence, the paper illustrates relevant implications of the different scenarios, which can be used by policymakers to develop more realistic and resilient strategies for reaching carbon neutrality.     

An assessment of biomass for bioelectricity and biofuel,and for greenhouse gas emission reduction in Australia

We provide a quantitative assessment of the prospects for current and future biomass feedstocks for bioenergy in Australia, and associated estimates of the greenhouse gas (GHG) mitigation resulting from their use for production of biofuels or bioelectricity. National statistics were used to estimate current annual production from agricultural and forest production systems. Crop residues were estimated from grain production and harvest index. Wood production statistics and spatial modelling of forest growth were used to estimate quantities of pulpwood, in‐forest residues, and wood processing residues. Possible new production systems for oil from algae and the oil‐seed tree Pongamia pinnata, and of lignocellulosic biomass production from short‐rotation coppiced eucalypt crops were also examined. The following constraints were applied to biomass production and use: avoiding clearing of native vegetation; minimizing impacts on domestic food security; retaining a portion of agricultural and forest residues to protect soil; and minimizing the impact on local processing industries by diverting only the export fraction of grains or pulpwood to bioenergy. We estimated that it would be physically possible to produce 9.6 GL yr^?1 of first generation ethanol from current production systems, replacing 6.5 GL yr^?1 of gasoline or 34% of current gasoline usage. Current production systems for waste oil, tallow and canola seed could produce 0.9 GL yr^?1 of biodiesel, or 4% of current diesel usage. Cellulosic biomass from current agricultural and forestry production systems (including biomass from hardwood plantations maturing by 2030) could produce 9.5 GL yr^?1 of ethanol, replacing 6.4 GL yr^?1 of gasoline, or ca. 34% of current consumption. The same lignocellulosic sources could instead provide 35 TWh yr^?1, or ca. 15% of current electricity production. New production systems using algae and P. pinnata could produce ca. 3.96 and 0.9 GL biodiesel yr^?1, respectively. In combination, they could replace 4.2 GL yr^?1 of fossil diesel, or 23% of current usage. Short‐rotation coppiced eucalypt crops could provide 4.3 GL yr^?1 of ethanol (2.9 GL yr^?1 replacement, or 15% of current gasoline use) or 20.2 TWh yr^?1 of electricity (9% of current generation). In total, first and second generation fuels from current and new production systems could mitigate 26 Mt CO₂‐e, which is 38% of road transport emissions and 5% of the national emissions. Second generation fuels from current and new production systems could mitigate 13 Mt CO₂‐e, which is 19% of road transport emissions and 2.4% of the national emissions lignocellulose from current and new production systems could mitigate 48 Mt CO₂‐e, which is 28% of electricity emissions and 9% of the national emissions. There are challenging sustainability issues to consider in the production of large amounts of feedstock for bioenergy in Australia. Bioenergy production can have either positive or negative impacts. Although only the export fraction of grains and sugar was used to estimate first generation biofuels so that domestic food security was not affected, it would have an impact on food supply elsewhere. Environmental impacts on soil, water and biodiversity can be significant because of the large land base involved, and the likely use of intensive harvest regimes. These require careful management. Social impacts could be significant if there were to be large‐scale change in land use or management. In addition, although the economic considerations of feedstock production were not covered in this article, they will be the ultimate drivers of industry development. They are uncertain and are highly dependent on government policies (e.g. the price on carbon, GHG mitigation and renewable energy targets, mandates for renewable fuels), the price of fossil oil, and the scale of the industry.     

Chemi-refiner mechanical pulping of flax shives: refining energy and fiber properties.

Oil-seed flax shive has been promoted as a raw material for low-end paper making because of its overall cost benefit over hardwood and groundwood pulp and increasing demand for low-cost pulp in rigid packaging applications. We have made refiner mechanical pulp from oil-seed shives by using a 300 mm Sprout-Bauer pilot refiner. The factors controlled during refining were: consistency, multi-pass refining, temperature, spacing between the plates and polyol-anhydride reactant concentration. Based on the results in this study it is apparent that unmodified shives develop low mechanical strength, shorter fibers and large amount of fines. Chemical modification of shives with a pre-reacted mixture of polyol-anhydride reduces refining energy consumption, improves strength performance but decreases scattering coefficient. From the results of investigation it is suggested that chemically modified refiner pulp from shives cannot be used for high-grade paper manufacture but it can be used as a low-cost filler for low-end applications in packaging or low-performance decorative papers.     

Enzymatic approaches in paper industry for pulp refining and biofilm control

The use of enzymes has a high potential in the pulp and paper industry to improve the economics of the paper production process and to achieve, at the same time, a reduced environmental impact. Specific enzymes contribute to reduce the amount of chemicals and energy required for the modification of fibers and helps to prevent the formation or development of biofilms. This review is aimed at presenting the latest progresses made in the application of enzymes as refining aids and biofilm control agents.     

青菜/油菜茬口下水稻栽植方式对温光资源利用和产量的影响

轻简化栽培和优质稻是当前我国水稻生产的主要方向,气象因子是对水稻生长发育和产量形成影响最大的环境因素,但在不同轻简化栽植方式下水稻产量与其田间小气候的关系鲜有研究。为探究西南地区不同前作下杂交稻各生育阶段温、光和水等气候因子与水稻产量形成的关系,在2019—2020年,以杂交籼稻‘宜香优2115'为试验材料,采用两因素裂区设计,主区为青菜和油菜2种前作,副区为机直播、毯苗机插和人工移栽3种栽植方式,研究杂交稻产量对气候因子的响应及水稻植株对温光资源的利用。结果表明: 与油菜-水稻模式相比,青菜-水稻模式下杂交稻积温生产效率和降水生产效率显著提高,进而提高了有效穗数、结实率和千粒重,2年产量分别提高了12.7%和8.3%。与人工移栽相比,机插稻提高了单位面积有效穗数、全生育期光能生产效率、积温生产效率、籽粒光能利用效率和降水生产效率,2年平均产量提高了4.6%;而机直播全生育期降水生产效率、光能生产效率、积温生产效率、籽粒光能利用效率、每穗粒数和千粒重都显著降低,导致2年平均产量下降了8.7%。与2019年相比,2020年机插稻和人工移栽稻在同一茬口下提前一个月播种造成花后生育期缩短、气温降低和降雨量增多,导致有效积温和光辐射量大幅减少,积温生产效率、光能生产效率、降水生产效率和籽粒光能利用效率以及每穗粒数、结实率和千粒重均大幅降低,进而导致产量严重降低。用偏最小二乘法回归分析建立的气象因子产量预报方程标准化回归系数显示,水稻产量与阶段生育期或全生育期内有效积温和总辐射量呈正相关关系,与全生育期内降水量呈显著负相关关系。综上,青菜-水稻模式下机插秧与西南地区稻季光温资源匹配度最高,更有利于温光资源的充分利用和获得高产,但不宜过早播种或移栽。