Greenhouse Gas Mitigation Technologies Research Articles

Techno-economic analysis of chemical looping processes with biomass resources for energy production and CO2 utilization. Comparison of CLC and CLOU technologies

Bioenergy coupled with carbon capture utilization and storage (BECCUS) is an attractive greenhouse gas mitigation technology that can produce negative CO2 emissions by combining bioenergy resources with the utilization or geological storage of the captured CO2.The main objective of this work was to evaluate the technical and economic feasibility of two BECCUS technologies based on chemical looping concept with two biomass waste as fuels, i.e., swine manure and pine sawdust, for the production of thermal energy and a pure CO2 stream that is subsequently used as raw material in agricultural greenhouses. Direct use of solid biomass resources was considered for the Chemical Looping with Oxygen Uncoupling option, whereas biogas production was the starting point for Chemical Looping Combustion.The profitability of the chemical looping scenarios was assessed through the Levelized Cost of CO2. This parameter was estimated at 218.31 €/t CO2 for the Chemical Looping Combustion scenario, a value much higher than those for the Chemical Looping with Oxygen Uncoupling scenarios (73.04–87.32 €/t CO2) due to the limited conversion degree of the carbon present in the fuel waste to biogas and the need for an additional experimental plant to the Chemical Looping Combustion unit, i.e., the biogas production plant. Comparing the Chemical Looping with Oxygen Uncoupling scenarios, the economic analysis revealed that the profitability of the biomass-fueled chemical looping facility was markedly sensitive to the selling price of the biomass resource. Furthermore, the values of the Levelized Cost of CO2 parameter for the Chemical Looping with Oxygen Uncoupling scenarios were lower than those estimated in other research studies that implemented BECCUS technologies and utilized the captured CO2 for identical purposes. In the particular case of swine manure, this result becomes even more noteworthy since it demonstrates that the energy use of this biomass resource through Chemical Looping with Oxygen Uncoupling technology is an economically profitable and environmentally sustainable solution to the difficult challenge of managing this livestock waste. Therefore, it can be concluded that Chemical Looping with Oxygen Uncoupling processes fed with biomass are a very attractive BECCUS technology for heat generation where, in addition, the pure CO2 stream obtained at the outlet of the fuel reactor can be considered a marketable, high value-added product.

‘Climate Healing Stones’: Common Minerals Offer Substantial Climate Change Mitigation Potential

This review proposes that mineral-based greenhouse gas (GHG) mitigation could be developed into a substantial climate change abatement tool. This proposal was evaluated via three objectives: (1) synthesise literature studies documenting the effectiveness of geological minerals at mitigating GHG emissions; (2) quantify, via meta-analysis, GHG magnitudes that could be abated by minerals factoring-in the carbon footprint of the approach; and (3) estimate the global availability of relevant minerals. Several minerals have been effectively harnessed across multiple sectors—including agriculture, waste management and coal mining—to mitigate carbon dioxide/CO2 (e.g., olivine), methane/CH4 (e.g., allophane, gypsum) and nitrous oxide/N2O (e.g., vermiculite) emissions. High surface area minerals offer substantial promise to protect soil carbon, albeit their potential impact here is difficult to quantify. Although mineral-based N2O reduction strategies can achieve gross emission reduction, their application generates a net carbon emission due to prohibitively large mineral quantities needed. By contrast, mineral-based technologies could abate ~9% and 11% of global CO2 and CH4 anthropogenic emissions, respectively. These estimates conservatively only consider options which offer additional benefits to climate change mitigation (e.g., nutrient supply to agricultural landscapes, and safety controls in landfill operations). This multi-benefit aspect is important due to the reluctance to invest in stand-alone GHG mitigation technologies. Minerals that exhibit high GHG mitigation potential are globally abundant. However, their application towards a dedicated global GHG mitigation initiative would entail significant escalation of their current production rates. A detailed cost-benefit analysis and environmental and social footprint assessment is needed to ascertain the strategy’s scale-up potential.

Prediction of Carbon Price in EU-ETS Using a Geometric Brownian Motion Model and Its Application to Analyze the Economic Competitiveness of Carbon Capture and Storage

To achieve carbon neutrality, many countries and regions are making efforts to promote the commercialization of greenhouse gas (GHG) mitigation technologies using emissions trading systems (ETSs). Accurate predictions of when the cost of GHG reduction technologies will become competitive below carbon prices could be invaluable to engineers and policy makers. In this study, carbon price movement in the EU-ETS was analyzed using a geometric Brownian motion (GBM) model. Using daily price data for the last 10 years, it tested whether the price pattern of the latter three years could be predicted by applying the first seven years of data to the GBM model. The results showed that the GBM model could well predict the upper and lower bounds of the actual carbon price. Based on the acceptable predictability of the GBM model, simulations were performed using carbon price data over the last decade, showing that carbon prices would reach around 200 EUR/tCO2 by the start of 2026. This is higher than the cost of CO2 avoided evaluated from the costs of commercial-scale carbon capture facilities for coal-fired power plants. This means that carbon capture technologies in the coal-fired power sector could become economically competitive within the next several years.

Analysis of Specific Greenhouse Gas Emissions Savings from Biogas Production Based on Agricultural Residues and Industrial By-Products

The aim of this study was to analyse specific greenhouse gas emissions savings for a variety of agricultural residues, industrial by-products, and municipal biowaste. One of the most viable alternatives to fossil fuels is bioenergy, particularly biogas produced by the anaerobic digestion of renewable feedstocks. The revised Renewable Energy Directive (D 2018/2001) recognizes that biogas production from agricultural residues, livestock production, and industrial by-products is an acknowledged greenhouse gas mitigation technology in cases where their use results in a certain level of specific greenhouse gas savings. This study delivered values for the maximum transport distance of agricultural residues and industrial by-products to achieve the greenhouse gas (GHG) emissions-saving requirement defined by Directive 2018/2001. It analysed the greenhouse gas emissions reduction for numerous feedstocks for which Directive 2018/2001 has not defined the default and typical values but which could be used as sustainable substitutes for currently dominantly used maize silage in biogas production. The results obtained in this work define the maximum transport and distribution distance for which biogas produced from considered feedstocks achieved required specific greenhouse gas emissions savings (80%), compared with fossil fuel comparator. The obtained results can be used as the constraints in the optimisation of the biomass supply chains for the feedstocks considered in this work.

Nuclear magnetic resonance studies of carbon dioxide capture

Carbon dioxide capture is an important greenhouse gas mitigation technology that can help limit climate change. The design of improved capture materials requires a detailed understanding of the mechanisms by which carbon dioxide is bound. Nuclear magnetic resonance (NMR) spectroscopy methods have emerged as a powerful probe of CO2 sorption and diffusion in carbon capture materials. In this article, we first review the practical considerations for carrying out NMR measurements on capture materials dosed with CO2 and we then present three case studies that review our recent work on NMR studies of CO2 binding in metal–organic framework materials. We show that simple 13C NMR experiments are often inadequate to determine CO2 binding modes, but that more advanced experiments such as multidimensional NMR experiments and 17O NMR experiments can lead to more conclusive structural assignments. We further discuss how pulsed field gradient (PFG) NMR can be used to explore diffusion of adsorbed CO2 through the porous framework. Finally, we provide an outlook on the challenges and opportunities for the further development of NMR methodologies that can improve our understanding of carbon capture.

Priorities for supporting emission reduction technologies in the cement sector – A multi-criteria decision analysis of CO2 mineralisation

As a major contributor to climate change, the cement sector urgently needs to develop and implement greenhouse gas (GHG) mitigation technologies to drastically lower its emissions to reach carbon neutrality by 2050. Among the most promising technologies is CO2 mineralisation in which CO2 is transformed into a thermodynamically stable carbonate. CO2 mineralisation not only offers permanent storage of CO2 but also potentially avoids emissions by partially substituting conventional cement with the obtained carbonation products. Besides overcoming technical barriers, successful development and implementation of CO2 mineralisation require support from key stakeholders. While existing studies already provide technology-related data and assess CO2 mineralisation pathways, knowledge remains scarce about stakeholder priorities and perceptions. Using a multi-stakeholder expert survey, the present study examines: a) the priorities of different stakeholders in supporting CO2 mineralisation, b) their perceptions on the performance of CO2 mineralisation concepts, and c) their priorities if tasked with communicating CO2 mineralisation technologies to other groups. Hereby, we follow a multi-criteria decision analysis approach, based on an analytical hierarchy process, by comparing indicators from the three common sustainability pillars (i.e., environmental, economic, and social impacts). Our results indicate that key stakeholders strongly prioritise the health implications of CO2 mineralisation technologies and generally value social impacts highly. Hence, an in-depth research is needed to provide knowledge-based guidance on health issues and ways to fairly distribute costs and create positive employment outcomes. Additionally, stakeholders of all affiliations give second priority to reducing carbon footprint of cement, showing that they discount potential environmental and economic trade-offs associated with emission reduction goals. The results reveal that these concepts are perceived as compatible with other GHG mitigation approaches, such as carbon capture and storage. Moreover, if tasked with convincing different target groups to support CO2 mineralisation, stakeholders prioritise diverse themes, recognising that communication strategies must address the specific concerns of each group. Overall, the results can help investors, managers, and policymakers to ensure that upcoming decisions in R&D, investments, and the design of support mechanisms align with the priorities of key stakeholders. Our results facilitate communicating technological potentials and risks and can foster successful development and implementation of CO2 mineralisation pathways.

Greenhouse gas mitigation technologies in agriculture: Regional circumstances and interactions determine cost-effectiveness

Agriculture, forestry and other land use are important components of a global strategy to limit climate change. Using the example of EU agriculture, this paper examines the potential contribution of technological (i.e. technical and management-based) greenhouse gas mitigation options to climate targets. The quantitative framework presented allows to analyze disparities between marginal abatement cost curves (MACCs) derived from two different commonly used approaches, and between aggregated and regional MACCs. Results highlight the importance of assessing mitigation of agricultural emissions from a multi-dimensional perspective, considering regional heterogeneity of biophysical and economic circumstances and comprising both carbon-dioxide (CO2) and non-CO2 emissions. Regarding the ranking of technologies in terms of mitigation potential and costs, the results underline the need to consider technologies in a combined manner, avoiding the simple aggregation of mitigation potentials by individual measures without taking their interactions into account. Focusing only on standalone MACCs can lead to an overestimation of the mitigation potential. Conversely, measures classified as relatively high cost in standalone and aggregated MACCs should not be discarded, as they can still be cost-effective in some regions. The analysis shows that there is no ‘one size fits all’ rule that could be followed for identifying technologies that should be implemented in all regions. From a policy perspective the results imply that farmers should be granted some flexibility to adopt a set of cost-effective mitigation options that best fits their circumstances.

Effect of different mitigation options on growth, productivity and economics of wheat (Triticum aestivum)

Wheat (Triticum aestivum L.) is second most important food grain after rice and is consumed in different forms. The production of wheat in India is currently facing new challenges due to increasing population and adverse impacts of climate change. The production of wheat has increased significantly after the introduction of high yielding varieties. Modern wheat cultivars require adequate amount of nitrogen (N) fertilizer and several irrigations for economical production. The amount and type of nitrogen fertilizers not only affect the production of wheat but also has impact on climate change due to emission of nitrous oxide. A field experiment was conducted in 2016-17 to study the impact of water management (3 and 5 irrigations) and nitrogen fertilizer (urea, neem coated urea (NCU), urea with thiourea, and leaf colour chart (LCC) based N application) on wheat production and profitability. The nitrogen-management practices and irrigation practices significantly influenced the yield parameters, cost of cultivation, net returns and benefit to cost ratio of wheat crop. Grain yield was increased by 15.89% (p ≥ 0.05) in 5 irrigations compared to 3 irrigations. The grain yield increased by 3.0%, 3.4% and 5.9% in treatments where N was applied using NCU, LCC based N application and urea + thiourea respectively, over urea treatment. Grain yield per kg of N applied was highest in LCC based N application treatment followed by thiourea + urea, NCU and urea N treatments. Highest gross returns was from thiourea treatment however the net returns and B: C ratio were highest in LCC based urea N application due to higher biological yield and saving of 20 kg nitrogen per ha. The study revealed that the economic performance of greenhouse gas mitigation technologies where N was applied based on the plant requirement using leaf colour chart and 5 irrigations was the best followed by application of nitrification inhibitor thiourea with urea and 5 irrigations.

Quantification of technological progress in greenhouse gas (GHG) capture and mitigation using patent data

Greenhouse gas emissions from anthropogenic sources are believed to be the main cause of global warming. We estimate performance improvement rates of various GHG capture and mitigation technologies using a method based on patent centrality.

Assessment of GHG mitigation and CDM technology in urban transport sector of Chandigarh, India.

The increase in number of vehicles in metropolitan cities has resulted in increase of greenhouse gas (GHG) emissions in urban environment. In this study, emission load of GHGs (CO, N2O, CO2) from Chandigarh road transport sector has been estimated using Vehicular Air Pollution Inventory (VAPI) model, which uses emission factors prevalent in Indian cities. Contribution of 2-wheelers (2-w), 3-wheelers (3-w), cars, buses, and heavy commercial vehicles (HCVs) to CO, N2O, CO2, and total GHG emissions was calculated. Potential for GHG mitigation through clean development mechanism (CDM) in transport sector of Chandigarh under two scenarios, i.e., business as usual (BAU) and best estimate scenario (BES) using VAPI model, has been explored. A major contribution of GHG load (~50%) in Chandigarh was from four-wheelers until 2011; however, it shows a declining trend after 2011 until 2020. The estimated GHG emission from motor vehicles in Chandigarh has increased more than two times from 1065Gg in 2005 to 2486Gg by 2011 and is expected to increase to 4014Gg by 2020 under BAU scenario. Under BES scenario, 30% of private transport has been transformed to public transport; GHG load was possibly reduced by 520Gg. An increase of 173Gg in GHGs load is projected from additional scenario (ADS) in Chandigarh city if all the diesel buses are transformed to CNG buses by 2020. Current study also offers potential for other cities to plan better GHG reduction strategies in transport sector to reduce their climate change impacts.

Impacts of technological change on energy use efficiency and GHG mitigation of pomegranate: Application of dynamic data envelopment analysis models

Greenhouse gas (GHG) mitigation in agriculture should be approached, among others, through changes in farm management and technology use. The application of new GHG mitigation technologies are essential to promote a cleaner environment. This is critical since not all new technologies are environmentally friendly. To understand whether and to what extent such technologies mitigate GHG, this survey study was conducted to measure the amount of the dynamic energy consumption and productivity growth of pomegranate production during 2009–2015 in the Fars province, Southwest Iran. Dynamic DEA models were employed for the efficiency analyses. The data were gathered from pomegranate gardeners through questionnaires by face-to-face interviews. The validity and reliability of the questionnaires were tested and confirmed respectively through a pilot study and Cronbach’s alpha. Using simple random sampling method, 55 pomegranate gardeners were chosen for the survey. The dynamic DEA revealed that our gardeners had the best performance in 2013, 2014 and 2015. The average energy consumption was 42,230 MJ/ha to produce 17,300 kg/ha pomegranate. The highest output-input energy ratio was also obtained in 2013, 2014 and 2015 of 1.013. The most efficient gardeners consumed more renewable energy especially in the form of farm yard manure. Accordingly, the gardeners with the least efficiency should enhance pomegranate yield and reduce the extra energy inputs of around 10,000 kg/ha (58% of average) and 25,000 MJ/ha (59% of the average), respectively. Malmquist index showed that the best efficient gardeners had annual positive technology change of 8.3%. Statistical analyses confirmed that each positive percentage of technology change reduces the energy input by 710 times and CO2 emission mitigation by 634 times meaning that the gardeners used some energy efficient technologies that lead to lower GHG emissions. The technology change can be predicted by some of the socio-demographic attributes of the gardeners such as farming experience, net income and participating in extensional classes. The study concludes that highly efficient pomegranate production besides new technology use policies would ultimately contribute to the robust climate change mitigation from this sector.

Construction of Greenhouse Gas Inventory of Private Industry of Chungcheongbuk-do and Analysis of Greenhouse Gas Mitigation Technology

Greenhouse gas (GHG) emissions of private industry of Chungcheongbuk-do were estimated. GHG emissions were classified by industry and GHG emissions ratio of each industry of Chungcheongbuk-do was found. Characteristics of GHG emissions of Chungcheongbuk-do and GHG mitigation technology were analyzed. To calculate GHG emissions, equations proposed through GHG emissions calculation guidelines published by Korean Energy Agency in 2009 were used. As a result, GHG emissions ratio of cement, semiconductor, paper and petrochemical industry was about 73%, 16%, 5%, and 2% respectively. GHG mitigation technologies of cement, semiconductor and waste were investigated. For cement, amine technology, for semiconductor, scrubber system and for waste, land fill gas utilization were analyzed.

Unintended possible consequences of fuel input taxes for individual investments in greenhouse gas mitigation technologies and the resulting emissions

Background: South Africa is planning to introduce a carbon tax as a Pigouvian measure for the reduction of greenhouse gas emissions, one of the tax bases designed as a fuel input tax. In this form, it is supposed to incentivise users to reduce and/or substitute fossil fuels, leading to a reduction of CO2 emissions.Aim: This article examines how such a carbon tax regime may affect the individual willingness to invest in greenhouse gas mitigation technologies.Setting: Mathematical derivation, using methods of linear programming, duality theory and sensitivity analysis.Methods: By employing a two-step evaluation approach, it allows to identify the factors determining the maximum price an individual investor would pay for such an investment, given the conditions of imperfect markets.Results: This price ceiling depends on the (corrected) net present values of the payments and on the interdependencies arising from changes in the optimal investment and production programmes. Although the well-established results of environmental economics usually can be confirmed for a single investment, increasing carbon taxes may entail sometimes contradictory and unexpected consequences for individual investments in greenhouse gas mitigation technologies and the resulting emissions. Under certain circumstances, they may discourage such investments and, when still undertaken, even lead to higher emissions. However, these results can be interpreted in an economically comprehensible manner.Conclusion: Under the usually given conditions of imperfect markets, the impact of a carbon tax regime on individual investment decisions to mitigate greenhouse gas emissions is not as straight forward as under the usually assumed, but unrealistically simplifying perfect market conditions. To avoid undesired and discouraging effects, policy makers cannot make solitary decisions, but have to take interdependencies on the addressee´s side into account. The individual investor´s price ceiling for such an investment in imperfect markets can be interpreted as a sum of (partially corrected) net present values, which themselves are a generalisation of the net present values known from perfect markets

Public Health Co-Benefits of the Diffusion of Innovative Greenhouse Gas Mitigation Technologies in Abu Dhabi

The emirate of Abu Dhabi has been active in the implementation of innovative technologies to reduce its carbon footprint from energy consuming activities in the power supply and transport sectors. While the reduction in GreenHouse Gas (GHG) emissions from these technologies has been quantified, to date, there has not been a comprehensive assessment of the positive impacts that such measures could have on public health. These are considered a “co-benefit” of GHG mitigation, namely the simultaneous improvement in air quality and public health associated with the dissemination of technologies that reduce GHG emissions. Public health co-benefits include reductions in the incidence of, for example, respiratory illnesses, cardiovascular disease, and allergies. A scenario-based, integrated damage model was developed to integrate local meteorology and air quality conditions, innovative technology performance characteristics in power supply and transport, demographic features/trends, and epidemiological dose-response functions. The results of the study indicate that future efforts in the Abu Dhabi Emirate to expand and intensify GHG-reducing activities using innovative technologies - particularly in the energy and transport sectors where the majority of potential GHG reductions exist - will lead to substantial public health co-benefits.

Mitigation of greenhouse gas emission from rice–wheat system of the Indo-Gangetic plains: Through tillage, irrigation and fertilizer management

Rice–wheat cropping systems (RWCS) of the Indo-Gangetic plains (IGP) of India are tillage, water and energy intensive and an important source of greenhouse gas (GHG) emission. Developing agronomic management in RWCS that lead to minimum adverse impact on soil, enhances water use efficiency, reduces GHG emission and are climate resilient is required. The aim of this study was to evaluate different combinations of GHG mitigation technologies for rice and wheat and to find suitable low carbon options for RWCS in the IGP. Seven management systems i.e. conventionally tilled wheat (CTW); zero tilled wheat (ZTW); transplanted puddled rice (TPR); dry direct seeded rice (DSR); intermittent wetting and drying (IWD); application of neem oil coated urea (NOCU); and surface application of rice residue (RR) were experimented in six combination of rotations [CTW-TPR, ZTW-TPR, ZTW-IWD, ZTW-DSR, ZTW+RR-DSR and (ZTW-TPR)+NOCU] for two consecutive years. Among these rotations, ZTW-DSR and ZTW+RR-DSR showed the lowest global warming potential (GWP) and GHG intensity in both the years. Adoption of these systems in the Indian-IGP can reduce GWP of the conventional RWCS (CTW-TPR) by 44–47% without any significant loss in the system yield. This was mainly due to significantly low CH4 emission (82.3–87.2%) in DSR as compared to TPR due to prolonged aerobic condition under DSR. However, frequent wetting and drying in DSR led to higher denitrification emissions of N2O (60–70%). Significantly higher emissions of N2O were observed in ZTW treatments (8–11%). NOCU was found effective in reducing N2O emission from ZTW (17.8–20.5%) leading to lower GWP as compared to CTW. Application of rice residue in ZTW treatment also reduced N2O emission (11–12.8%). There was no significant effect of different treatments in rice on GHG emission from the succeeding wheat crop; however, ZTW and ZTW+RR were found to enhance CH4 emission from the succeeding rice treatments.

Economic Analysis of Different Greenhouse Gas Mitigation Technologies in Rice-Wheat Cropping System of the Indo-Gangetic Plains

To reduce the greenhouse gas (GHG) emission from rice and wheat cultivation several mitigation options have been suggested. However, economic impact of these technologies has been poorly documented. In the present study economic analysis of some emerging GHG mitigation technologies for rice-wheat system of the Indo-Gangetic Plains has been carried out. The experiment consisted of six combinations of wheat- rice crop rotation using eight treatments, including conventionally tilled wheat (CTW), zero tilled wheat (ZTW), transplanted puddled rice (TPR), dry direct seeded rice (DSR), intermittent wetting and drying (IWD), application of rice straw (RS) with ZTW and use of neem oil-coated urea (NOCU) in TPR and ZTW. Cost of various inputs and income from grain and straw were used for computing the benefit to cost (B : C) ratio in the different treatments. ZTW showed higher yield and B : C ratio compared to CTW along with reduction in fuel consumption during tillage operation. In spite of lower yield under DSR and IWD, saving of water, labour and energy in these treatments lowered the cost of cultivation and enhanced B : C ratio similar to TPR. Application of rice straw and NOCU also showed positive impact on crop yield. B : C ratio of rice-wheat system ranged from 1.62 to 1.86 in the first year and from 1.86 to 2.16 in the second year. B : C ratio was significantly higher in all the treatments in the experimented rice-wheat system compared to conventional system, i.e. CTW-TPR. The ZTW + RR - DSR (WR5) showed highest B : C ratio followed by ZTW + DSR (WR4) in both the seasons.

A framework for technological learning in the supply chain: A case study on CdTe photovoltaics

Accounting for technological changes and innovation is important when assessing the implications of rapidly-developing greenhouse gas (GHG) mitigation technologies. Technological learning curves have been commonly used as a tool to understand technological change as a function of cumulative production. Traditional learning curve approaches, however, do not distinguish the direct and upstream, supply chain technological changes by which cost reductions are achieved. While recent advances in learning curves have focused on distinguishing the different physical and economic drivers of learning, forecasted technological changes have not been applied to estimate the potential changes in the environmental performance of a technology. This article illustrates how distinguishing the different effects of technological learning throughout the supply chain can help assess the changing costs, environmental impacts and natural resource implications of technologies as they develop. We propose a mathematical framework to distinguish the effects of learning on the direct inputs to a technology from the effects of learning on value added, and we incorporate those effects throughout the supply chain of a technology using a life cycle assessment (LCA) framework. An example for cadmium telluride (CdTe) photovoltaics (PV) illustrates how the proposed framework can be implemented. Results show that that life cycle GHG emissions can decrease at least 40% and costs can decrease at least 50% as cumulative production of CdTe reaches 100GW. Technological learning in supply chain processes can further reduce emissions and costs by up to 1–2%. Lastly, we discuss the implications of using this new technological learning framework in the long-term assessment of the costs, environmental impacts and resource requirements of technologies using life-cycle assessment.

Comparison of Pine Bark, Biochar and Zeolite as Sorbents for NH4+‐N Removal from Water

To assist the adoption of biochar production as a greenhouse gas mitigation technology, evidence is required that biochar can provide additional economic benefits covering its current cost of manufacture. Biochar has the potential to be used as sorbent for NH4+‐N removal from wastewaters. Two batch studies were conducted to compare (i) sorption of NH4+‐N on pine biochars with different particle sizes and (ii) sorption of NH4+‐N on pine biochar in comparison to alternative sorbents, zeolite (clinoptilolite) and pine bark. Decreasing the particle size of the feedstock (pine chip), or the biochar by crushing after pyrolysis, did not affect its NH4+‐N sorption properties. Sorption of NH4+‐N on comparative sorbents, when added at a dose of 39 mg NH4+‐N L−1, followed the order zeolite > biochar > bark. Zeolite proved to be the most efficient sorbent for NH4+‐N g−1 removal followed by biochar and bark. Biochar has the potential to be used as a cost effective commercial sorbent for removing NH4+‐N from waste streams.

Implications and future direction of greenhouse gas emission mitigation policies in the building sector of China

Abstract A common starting point in assessing greenhouse gas (GHG) reduction policy implications in the built environment is to look at industry specific policies. This paper addressed the glaring gap between national all-economy policy options that actually determine industry-specific programs, and their downstream impacts and implications to the building and construction sector. National carbon policy schemes were organised into two basic types: indirect pricing mechanisms, and direct pricing mechanisms. Their features and comparative strengths and limitations were critically reviewed under a common framework, drawing from a wide body of literature. The status of the application of the GHG reduction policies in China was reviewed. A green building case is studied to quantitatively present the effectiveness and deficiencies of the current GHG mitigation policies in the building sector of China, and their implications to a building's life cycle. Based on China's current status of the policy system, this paper identifies the future direction of building's GHG mitigation policies of China. Policies directly aiming to GHG mitigation in the building sector should be implemented in holistic and comprehensive pathway, to balance the costs and benefits of the stakeholders for the promotion of building GHG mitigation technologies.

The Impact of Offshore Wind Farms on Marine Ecosystems: A Review Taking an Ecosystem Services Perspective

The rapid increase in renewable energy generation from wind has increased concerns about the impacts that wind arrays have on the marine environment and what these impacts mean for society. One method for identifying the impacts of offshore wind farms (OWFs) on human welfare is through the assessment and valuation of ecosystem services. Using an ecosystem services approach, this paper reviews the impacts of OWFs on the ecosystem services delivered by marine environments. During the construction phase, supporting services such as reduced energy capture and nutrient cycling are changed due to the introduction of hard substrate and the reduction in soft sediment habitat at turbine bases. This may lead to changes in all other ecosystem services, both negative and positive. Quantifying these changes, however, is a challenge partly due to data limitations and a lack of clear understanding of the impacts of OWFs on the marine ecosystems. Scientific effort needs to quantitatively explore the impacts of OWFs on ecosystem functionality and the gathering of data that enables the assessment of changes to ecosystem services. Data needed to better quantify and value the impacts of OWFs on ecosystem services are suggested. The development of methods which integrate socioeconomic valuation of ecosystem services into the evaluation of renewable energy devices compliments efforts in assessing the environmental impacts and should enable a holistic assessment of the impact of renewable energy production and greenhouse gas mitigation technologies on the U.K. carbon footprint.