Suchergebnisse

China encounters heavy air pollution caused by coal consumption. China and the EU aim to decrease greenhouse gas emissions. Shifting to biogas from residues contributes to solving both problems. This study assesses China's biogas potentials and related water footprints (WFs) and compares results with potentials and WFs for the EU. Starting from a literature review on EU biogas potentials, it analyzes information resulting in a calculation methodology, its validation and application to China. Finally, it estimates WFs and makes a comparative assessment of biogas potentials of the EU and China. In the EU, biogas from agricultural, forestry and other residues might contribute 8% (5300 PJ) to primary energy consumption, in China 10% (13,275 PJ.) In the EU, agriculture contributes 41%, forestry 26%, other residues 23%, and manure 10%. The corresponding results for China are agriculture (67%), forestry (23%), manure (7%) and other residues (3%). In the EU, biogas might contribute 45% to total gas demand; in China more biogas can be produced than consumed in 2018 (185% of demand). The EU results fall in the range of residue potentials from earlier studies. Maize, wheat, barley and rapeseed contribute 78% to the EU agricultural biogas potential. In China, dominant crops are maize (49%), rice (18%), wheat (12%) and seed cotton (6%). For water, there are large differences among WFs of specific crop residues, but also between WFs for EU and Chinese crop residues. Most Chinese crop residues have larger WFs than the EU residues. Biogas from sugar beet residues has the smallest WFs, biogas from tobacco residues the largest. Although using residues for energy does not change total national WFs, it reallocates WFs over main products and residues. The comparative assessment supports better use of biogas potentials from residues with lower WFs and is also applicable for other regions and countries. ; ISSN:0048-9697 ; ISSN:1879-1026

This report aims to identify the current state of business water accounting and to design an accounting method for the business water footprint (BWF). It answers the following questions: (i) What are the main developments in sustainable business performance so far? (ii) What is the current state of business water accounting? (iii) How to design an accounting method for the business water footprint? And (iv) How to apply the method for existing situations? The term "business" is interpreted in this study in a broad sense, in order to include any form of enterprise, governmental or non-governmental organization or other form of business activity. Based on the methodology of the WF concept, this report designs an accounting method for the BWF. The method calculates the BWF per business unit, where a business unit is preferably a part of the business that produces one homogenous product (good or service) at one particular spot. The WF of a business unit is defined as the total volume of freshwater that is used, directly and indirectly, to produce the goods and services delivered by that unit expressed in terms of the volume of freshwater use per year. The WF of a business is defined as the total volume of freshwater that is used directly or indirectly to run and support the business.

This study builds upon the explorative study of Hoekstra (2006), who puts forward an argument for coordination at the global level in 'water governance'. Water governance is understood here in the broad sense as 'the way people use and maintain water resources'. One of the factors that give water governance a global dimension is 'virtual water trade' between nations, i.e. the trade in water in virtual form through trade in water-containing products. Virtual water trade involves advantages as well as disadvantages. The development of institutional arrangements to account for these disadvantages has not kept pace with the enhancement of international trade in general and virtual water trade in particular. The objective of this study is to design alternative institutional arrangements to deal with the global dimension of water governance. The study elaborates three arrangements: a Water Pricing Protocol, a Business Agreement on Sustainability Reporting of water-intensive goods, and a system of Water Footprint Permits. The three institutional arrangements are aimed to improve the ecological sustainability, economic efficiency and social equity of water governance. The arrangements aim to influence change agents in the virtual water chain (the production chain of water-containing products). Behavioural mechanisms bring about behavioural change of other agents in the virtual water chain.

Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China based on data from 875 representative reservoirs (209 with power plants). In 2010, the reservoir WF totaled 27.9 × 109 m3 (Gm3), or 22% of China's total water consumption. Ignoring the reservoir WF seriously underestimates human water appropriation. The reservoir WF associated with industrial, domestic and agricultural WFs caused water scarcity in 6 of the 10 major Chinese river basins from 2 to 12 months annually. The hydropower WF was 6.6 Gm3 yr−1 or 3.6 m3 of water to produce a GJ (109 J) of electricity. Hydropower is a water intensive energy carrier. As a response to global climate change, the Chinese government has promoted a further increase in hydropower energy by 70% by 2020 compared to 2012. This energy policy imposes pressure on available freshwater resources and increases water scarcity. The water-energy nexus requires strategic and coordinated implementations of hydropower development among geographical regions, as well as trade-off analysis between rising energy demand and water use sustainability.

Bioethanol production from non-crop based lignocellulosic material has reached the commercial scale and is advocated as a possible solution to decarbonize the transport sector. This study evaluates how much presently used transport related fossil fuels can be replaced with lignocellulosic bioethanol using crop residues, calculates greenhouse gas emission savings, and determines lignocellulosic bioethanol's land, water, and carbon footprints. We estimate global bioethanol production potential from 123 crop residues in 192 countries and 20 territories under different environmental constraints (optimistic and realistic sustainable potentials) versus no constraints (theoretical potential) on residue availability. Previous studies on global bioethanol production potential from lignocellulosic material focused on one or few biomass feedstocks, and excluded (un)constrained residue availability scenarios. Our results suggest the global net lignocellulosic bioethanol output ranges from 7.1 to 34.0 EJ per annum replacing between 7% and 31% of oil products for transport yielding relative emission savings of 338 megatonne (Mt; 70%) to 1836 Mt (79%). Emission savings range from 4% to 23% of total transport emissions in the realistic sustainable versus theoretical potential. Land, water and carbon footprints of net bioethanol vary between potentials, countries/territories, and feedstocks, but overall exceed footprints of conventional bioethanol. Averaged footprints range between 0.14 and 0.24 m2 land per megajoule (MJ−1), 74–120 L water MJ−1, and 28–44 g CO2 equivalent MJ−1, with smaller footprints in the theoretical potential caused by the exclusion of secondary residues and low price of alternative biomass chains in the sustainable potential. ; Authors B.H., J.F.S., and M.S.K, gratefully acknowledge funding by the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 689669 (MAGIC). This work reflects the author's views only; the funding agencies are not responsible for any use that may ...

The trend towards substitution of conventional transport fuels by biofuels requires additional water. The EU aims In the last two centuries, fossil fuels have been our major source of energy. However, issues concerning energy security and the quality of the environment have given an impulse to the development of alternative, renewable fuels. Particularly the transport sector is expected to steadily switch from fossil fuels to a larger fraction of biofuels - liquid transport fuels derived from biomass. Many governments believe that biofuels can replace substantial volumes of crude oil and that they will play a key role in diversifying the sources of energy supply in the coming decades. The growth of biomass requires water, a scarce resource. The link between water resources and (future) biofuel consumption, however, has not been analyzed in great detail yet. Existing scenarios on the use of water resources usually only consider the changes in food and livestock production, industry and domestic activity. The aim of this research is to assess the change in water use related to the expected increase in the use of biofuels for road transport in 2030, and subsequently evaluate the contribution to potential water scarcity. The study builds on earlier research on the relation between energy and water and uses the water footprint (WF) methodology to investigate the change in water demand related to a transition to biofuels in road transport. Information about this transition in each country is based on a compilation of different energy scenarios. The study distinguishes between two different bio-energy carriers, bio-ethanol and biodiesel, and assesses the ratio of fuel produced from selected first-generation energy crops per country. For ethanol these crops are sugar cane, sugar beet, sweet sorghum, wheat and maize. For biodiesel they are soybean, rapeseed, jatropha, and oil palm.