Net Carbon Dioxide Emissions Research Articles

Numerical Analysis of The Temperature Characteristics of a Coal—Supercritical Water-Fluidized Bed Reactor for Hydrogen Production

Supercritical water gasification (SCWG) of coal is a promising clean coal technology, which discards the traditional coal combustion and oxidation reaction to release carbon dioxide and other pollutants and replaces coal with a gasification reduction reaction in supercritical water to finally convert coal into a hydrogen-rich gas product with no net carbon dioxide emissions and no pollutant emissions, and thus has received much attention in recent years. However, the experimental conditions of coal to the hydrogen reactor are harsh, costly, and not easy to visualize and analyze, so numerical calculation and simulation analysis are important for the design, optimization, and industrial scaling-up of the reactor. In order to study the effect of the temperature field on the hydrogen production rate of the coal supercritical water gasification hydrogen production reactor, a numerical simulation calculation model is developed for this reactor in this paper. Comparing the experimental data in the literature, the maximum relative error of the gasification product yield per kg of coal between the two is less than 5%, which verifies the accuracy of the model built and the numerical method adopted in this paper. On this basis, the effects of supercritical water temperature and coal slurry temperature on the reactor’s gasification products and reaction rate were investigated in depth. The results show that increasing the supercritical water temperature is beneficial to improve the reactor hydrogen production efficiency, while the high coal slurry temperature is not conducive to adequate reaction, thus reducing the hydrogen production efficiency. For the laboratory coal supercritical water gasification to hydrogen reactor studied in this paper, the ideal temperature of supercritical water is 850~900 K, and the ideal temperature of coal slurry is 400–450 K. The conclusions of this paper can provide some reference for subsequent industrial scale-up studies of the reactor.

Smart photovoltaic system for Indian smart cities: a cost analysis.

In this paper, a methodology and optimization using the artificial bee colony (ABC) algorithm for life cycle cost (LCC) assessment of photovoltaic (PV) system for some Indian smart cities have been presented. Smart cities are the urban areas that utilize solar power PV system with other advanced innovations. The life cycle cost with and without carbon credit earned due to solar power generation in particular smart city should be known. Smart cities aim to assist local bodies in assessing their present energy consumption and future demand. This paper also focuses on PV energy generation, savings, and efficiency with cost. Four smart cities have been selected for LCC estimation on different field condition basis. The results show that in Srinagar, energy production is maximum, i.e., 435MWh, and LCC is minimum INR4125 million with an 8.9% rate of return on it. Therefore, net carbon dioxide emission reduction per annum for smart PV system over a lifetime of 20years is 76.5 tCO2e on the overall thermal energy and 17.7 tCO2e on the overall exergy gain. LCC of smart PV system for different years has been estimated and optimized using the ABC algorithm, and the results show a 50.24% reduction in LCC. With the proposed approach, future opportunities for smart cities with smart PV system can be revealed.

Can fossil energy make a soft landing？— the carbon-neutral pathway in China accompanying CCS

Carbon capture and storage (CCS) is an essential technology in the portfolio of emission mitigation solutions. The trade-off between fossil energy substitution and CCS has essential implications for achieving carbon-neutral at an affordable cost. This study couples the technology cost curve of CCS with a dynamic computable general equilibrium (DCGE) model and explores the carbon emission scale, energy structure, and emission abatement cost in the path of carbon neutrality under different CCS penetration scenarios. The results illustrate that the emission abatement cost increases fast if only relying on the emission trading scheme (ETS). Even at a high carbon price (3500 CNY/Ton), the net carbon dioxide emission will remain at 1.5 Gt in 2060, and the average emission abatement cost is 1211 CNY/Ton. The realization of net-zero emission requires synergy between ETS and CCS. The integration of CCS can significantly alleviate the economic cost when the emission mitigation scale is more remarkable than 5.2 Gt/year. The average emission abatement cost in 2060 is 557CNY/Ton under the high CCS penetration (4.3 Gt/year) and low carbon price (700CNY/Ton) carbon-neutral scenario.

River ecosystem metabolism and carbon biogeochemistry in a changing world.

River networks represent the largest biogeochemical nexus between the continents, ocean and atmosphere. Our current understanding of the role of rivers in the global carbon cycle remains limited, which makes it difficult to predict how global change may alter the timing and spatial distribution of riverine carbon sequestration and greenhouse gas emissions. Here we review the state of river ecosystem metabolism research and synthesize the current best available estimates of river ecosystem metabolism. We quantify the organic and inorganic carbon flux from land to global rivers and show that their net ecosystem production and carbon dioxide emissions shift the organic to inorganic carbon balance en route from land to the coastal ocean. Furthermore, we discuss how global change may affect river ecosystem metabolism and related carbon fluxes and identify research directions that can help todevelop better predictions of the effects ofglobalchange on riverine ecosystem processes. We argue that a global river observing system will play a key role in understanding river networks and their future evolution in the context of the global carbon budget.

Study on the hydrophobic modification of PVDF membrane by low-temperature plasma etching in combination with grafting in supercritical carbon dioxide

Poly (vinylidene fluoride) (PVDF) membrane has good resistance to acid and alkali, chemical stability, high mechanical strength, piezoelectric performance features, especially has good hydrophobic, can be used as blood purification, aerospace flexible sensor pieces, architectural membrane material, water desalination, etc., but for a particular application scenario, the hydrophobic properties still need further improvement. In this study, based on the principle of bionics, low-temperature plasma was used to construct a rough structure and generate active groups on the PVDF membrane surface. Fluorinated monomers were grafted onto the PVDF membrane in supercritical carbon dioxide (scCO2) fluid. The bionic effect of the lotus leaf was constructed on the membrane surface, and the hydrophobicity of the PVDF membrane was significantly improved. The results showed that the rough structure of the PVDF membrane surface was better when the plasma etching conditions were 600W and 300s. When PVDF membrane was swelled for 3h at 35 °C and 13.56 MPa, and grafted for 6h at 100.7°Cand 26.08MPa in scCO2, the PVDF membrane contact angle could reach 140.6°, which was close to superhydrophobic. The hydrophobic reagent was covalently grafted onto the surface of the PVDF membrane by Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis. The atomic force microscopy (AFM) test showed that the membrane surface modified by this method had a combination of micro and nanostructure. Further, it confirmed the contribution of a rough surface with low surface energy to water resistance. The processing method meets the requirements of peak carbon emission and net zero carbon dioxide emission, which has important guiding significance for developing hydrophobic surfaces.

Scoping carbon dioxide removal options for Germany–What is their potential contribution to Net-Zero CO2?

In its latest assessment report the IPCC stresses the need for carbon dioxide removal (CDR) to counterbalance residual emissions to achieve net zero carbon dioxide or greenhouse gas emissions. There are currently a wide variety of CDR measures available. Their potential and feasibility, however, depends on context specific conditions, as among others biophysical site characteristics, or availability of infrastructure and resources. In our study, we selected 13 CDR concepts which we present in the form of exemplary CDR units described in dedicated fact sheets. They cover technical CO2 removal (two concepts of direct air carbon capture), hybrid solutions (six bioenergy with carbon capture technologies) and five options for natural sink enhancement. Our estimates for their CO2 removal potentials in 2050 range from 0.06 to 30 million tons of CO2, depending on the option. Ten of the 13 CDR concepts provide technical removal potentials higher than 1 million tons of CO2 per year. To better understand the potential contribution of analyzed CDR options to reaching net-zero CO2 emissions, we compare our results with the current CO2 emissions and potential residual CO2 emissions in 2050 in Germany. To complement the necessary information on technology-based and hybrid options, we also provide an overview on possible solutions for CO2 storage for Germany. Taking biophysical conditions and infrastructure into account, northern Germany seems a preferable area for deployment of many concepts. However, for their successful implementation further socio-economic analysis, clear regulations, and policy incentives are necessary.

Explainable AI-driven net-zero carbon roadmap for petrochemical industry considering stochastic scenarios of remotely sensed offshore wind energy

Recently, several countries have focused on industrial decarbonization to ensure that the net emissions of carbon dioxide reach zero and contribute to decreasing the global mean temperature. This study aims to investigate the feasibility of a net-zero carbon roadmap for the petrochemical industry by 1) developing an explainable artificial intelligence (XAI)-based generative model to produce stochastic scenarios for offshore wind power in an electrical grid, and 2) conducting techno-economic and environmental assessments for forecasting models that define offshore wind power networks. Firstly, data processing techniques were utilized on remotely sensed offshore wind speed datasets and energy data obtained from petrochemical industrial parks. Second, a generative model was designed using a variational autoencoder (VAE) to produce different forecast scenarios of offshore wind power. Third, stochastic scenarios were developed by considering behavioral characteristics of offshore wind power with stochastic scenario uncertainties. Finally, we investigated the techno-economic and environmental assessments of the proposed renewable energy networks. Comparing to the case of offshore wind power in 2022, The proposed XAI-driven net-zero carbon roadmap indicated that the total cost of electricity generation and fossil fuel cost with carbon capture and storage (CCS) can be reduced by 4% and 42% with 41% reduction of CO2 emission. Ultimately, this may be implemented in industrial parks to aid in efforts towards carbon neutrality.

Scaling up climate ambition post-2030: a long-term GHG mitigation analysis for Thailand

ABSTRACT Thailand’s Nationally Determined Contribution (NDC) submitted to the United Nations Framework Convention on Climate Change (UNFCCC) aims to reduce 20 to 25% of greenhouse gas (GHG) emissions with respect to the projected reference level of NDC in 2030, respectively, in its unconditional and conditional scenarios. The Intergovernmental Panel on Climate Change (IPCC) states that limiting global temperature rise to 1.5°C would require net zero carbon dioxide emissions globally by around 2050. Thailand’s current energy system is highly fossil fuel dependent and requires enormous transformations to achieve more stringent GHG emission reduction targets beyond its NDC. This paper seeks to estimate the level and the intensities of Thailand’s energy system and their economy-wide effects post-2030 under the business as usual and 16 GHG emission reduction scenarios ranging from 30 to 100% by 2050. A computable general equilibrium analysis using the AIM/Hub model is employed to estimate the macroeconomic impacts of meeting the unconditional and conditional emission reductions of Thailand’s NDC in 2030 along with varying GHG emission reductions in 2050. Results show that renewables – constituting solar, wind, biomass and hydro and carbon capture and storage (CCS) technologies account for more than 95% in the power generation mix by 2050, if 100% GHG emission reduction from the 2010 level is to be achieved. Electricity generation based on biomass both with and without CCS will occupy a major share in the investments by 2050 in all the conditional and unconditional NDC scenarios. A rapid increase in carbon sequestration occurs from 2040 onwards through the deployment of CCS and bioenergy with CCS (BECCS) technologies in all the conditional and unconditional NDC scenarios. Carbon prices lie in the range of 3.4–266.2 US$/tCO2eq during 2025–2050 to achieve 100% GHG emission reductions in 2050. Imposition of early stringent mitigation target lowers the carbon prices in the conditional scenarios towards 2050 when compared to the unconditional scenarios. The rapid uptake of CCS, energy efficiency improvements and electrification of the end-use technologies are identified to be the key measures to transform the energy system of Thailand. Key policy insights By 2050, the Thai economy would face a higher fall in both the GDP and household consumption in the unconditional scenarios than those in the conditional scenarios at all levels of GHG emission reduction. Results indicate that early mitigation efforts can be less costly than the delayed ones in the long-term. The cumulative investment needed to achieve decarbonization in Thailand is estimated to exceed 355 billion US$2005 over the period 2010–2050 in the 100% GHG reduction scenarios. The transmission and distribution investments in the power sector need to increase by 30–35% to attain 100% GHG emission reductions during 2010–2050. The trade deficit improves by up to 23–29% in the various GHG mitigation scenarios in 2050.

Net Zero: Science, Origins, and Implications

This review explains the science behind the drive for global net zero emissions and why this is needed to halt the ongoing rise in global temperatures. We document how the concept of net zero carbon dioxide (CO2) emissions emerged from an earlier focus on stabilization of atmospheric greenhouse gas concentrations. Using simple conceptual models of the coupled climate–carbon cycle system, we explain why approximately net zero CO2 emissions and declining net energy imbalance due to other climate drivers are required to halt global warming on multidecadal timescales, introducing important concepts, including the rate of adjustment to constant forcing and the rate of adjustment to zero emissions. The concept of net zero was taken up through the 5th Assessment Report of the Intergovernmental Panel on Climate Change and the United Nations Framework Convention on Climate Change (UNFCCC) Structured Expert Dialogue, culminating in Article 4of the 2015 Paris Agreement. Increasing numbers of net zero targets have since been adopted by countries, cities, corporations, and investors. The degree to which any entity can claim to have achieved net zero while continuing to rely on distinct removals to compensate for ongoing emissions is at the heart of current debates over carbon markets and offsetting both inside and outside the UNFCCC. We argue that what matters here is not the precise makeup of a basket of emissions and removals at any given point in time, but the sustainability of a net zero strategy as a whole and its implications for global temperature over multidecadal timescales. Durable, climate-neutral net zero strategies require like-for-like balancing of anthropogenic greenhouse gas sources and sinks in terms of both origin (biogenic versus geological) and gas lifetime.

Applications of Hydrochar and Charcoal in the Iron and Steelmaking Industry—Part 1: Characterization of Carbonaceous Materials

The iron and steelmaking industry faces the dilemma of the need to decrease their greenhouse gas emissions to align with decarbonization goals, while at the same time fulfill the increasing steel demand from the growing population. Replacing fossil coal and coke with biomass-based carbon materials reduces the net carbon dioxide emissions. However, there is currently a shortage of charcoal to fully cover the demand from the iron and steelmaking industry to achieve the emission-reduction goals. Moreover, the transportation and energy sectors can compete for biofuel usage in the next few decades. Simultaneously, our society faces challenges of accumulation of wastes, especially wet organic wastes that are currently not reused and recycled to their full potentials. Here, hydrothermal carbonization is a technology which can convert organic feedstocks with high moisture contents to solid fuels (hydrochar, one type of biochar) as an alternative renewable carbon material. This work studied the differences between a hydrochar, produced from lemon peels (Lemon Hydrochar), and two types of charcoals (with and without densification) and an Anthracite coal. Characterizations such as chemical and ash compositions, thermogravimetric analyses in nitrogen and carbon dioxide atmospheres, scanning electron microscope analyses of carbon surface morphologies, and pyrolysis up to 1200 °C were performed. The main conclusions from this study are the following: (1) hydrochar has a lower thermal stability and a higher reactivity compared to charcoal and Anthracite; (2) densification resulted in a reduction of the moisture pickup and CO2 reactivity of charcoal; (3) pyrolysis of Lemon Hydrochar resulted in the formation of a large amount of tar (17 wt%) and gas (39 wt%), leading to its low fixed carbon content (27 wt%); (4) a pyrolyzed hydrochar (up to 1200 °C) has a comparable higher heating value to those of charcoal and Anthracite, but its phosphorous, ash, and alkalis contents increased significantly; (5) based on the preliminary assessment, hydrochar should be blended with charcoal or Anthracite, or be upgraded through slow pyrolysis to fulfill the basic functions of carbon in the high-temperature metallurgical processes.

Centennial Memory of the Arctic Ocean for Future Arctic Climate Recovery in Response to a Carbon Dioxide Removal

AbstractUnder the ongoing and potential risks from anthropogenic warming, net negative carbon dioxide (CO2) emissions are inevitable to stabilize or recover the Earth's climate. It is important not only to understand climate irreversibility in response to CO2 removal but also to understand how fast each component of the climate system will recover to its original state. Based on idealized CO2 ramp‐up and ‐down ensemble simulations, here we show that the initial buoyancy states of the Arctic Ocean, such as upper ocean salinity and density, are vital to determining how fast Arctic and global mean temperatures will recover on a centennial time scale. The denser initial Arctic oceanic condition is linked to faster recovery of the Atlantic meridional overturning circulation (AMOC) in the ramp‐down period, which is further accelerated by strong positive AMOC‐salt‐advection feedback. Faster AMOC recovery can delay Arctic temperature recovery by transporting warmer water into the northern subpolar Atlantic during the ramp‐down period. In addition, denser Arctic water enhances vertical mixing, which also results in delayed Arctic cooling under a strong vertical temperature gradient in the subpolar‐to‐polar Atlantic. Our findings suggest that the Arctic's initial states have a centennial memory for the future Arctic and global climate changes.

Hydrogen peroxide for fuel oxidation to achieve CO2 capture from lime production

• New concept & process for direct capture of carbon dioxide in lime production. • Use of an aqueous hydrogen peroxide mixture as an oxidiser instead of air. • Adiabatic flame temperature with aqueous hydrogen peroxide mixture as oxidiser. • Process models in Aspen Plus and comprehensive sensitivity analysis. Lime production is a highly carbon-intensive process for which new technology for carbon dioxide capture is needed, if it is to meet zero-emission targets. Hydrogen peroxide is an oxidant that decomposes exothermically to oxygen and water. That is, it can potentially be used as an alternative oxidant to air for the combustion of the hydrocarbon fuels, thereby avoiding the dilution of the product flue gas with nitrogen, which is otherwise present in air combustion, and enabling the direct capture of carbon dioxide. This paper presents a preliminary thermo-dynamic assessment of this potential use of hydrogen peroxide, here introduced as an aqueous solution The adiabatic flame temperature for the combustion of methane or carbon (as surrogates for natural gas and coal/biomass respectively) is estimated for various concentrations of hydrogen peroxide in water and compared with those for the combustion of methane and carbon with air. Also reported is a plausible approach for heat recovery in the lime-manufacturing process, which provides the enthalpy for vaporisation of the aqueous solution of hydrogen peroxide by heat recovery from the flue gases. The performance of the proposed process was evaluated using Aspen Plus software. The net carbon dioxide captured, emitted and avoided are compared with those from a reference cycle, together with the first law efficiency of the cycle and the fraction of energy supplied from the fuel. Also reported is the sensitivity of the performance to variation in key operating parameters. This reveals the importance of the carbon footprint of the upstream processing options to produce the hydrogen peroxide on the net carbon dioxide emissions of the process. The potential viability and challenges of the proposed system are also discussed.

Comparison of waste heat recovery exchangers of furnace combusted with different fuels

This study investigates and compares the low-temperature waste heat recovery exchangers of glass melting furnaces using liquid natural gas (LNG), methanol and dimethyl ether (DME) as fuels. A glass melting furnace with a production of 1 t/year was used to combust the fuel with air, and the waste heat exchanger served to recover the heat from the flue gas at a low temperature to preheat the air. The net present value (NPV) and carbon dioxide (CO2) emissions acted as the evaluating parameters of the heat exchanger. The results showed that the methanol combustion programme yielded the maximum NPV and carbon dioxide emissions. The LNG combustion programme yielded the lowest values and the parameters in the DME combustion programme are always in the middle. Considering the income of the heat exchanger and carbon dioxide emissions, the glass melting furnace with DME as the fuel is the optimal programme.

Key prospects and major development of hydrogen and bioethanol production

Cheap Production of bioethanol from renewable lignocellulosic waste has the imperative potential to economically cut burgeoning world dependency on fossils while reducing net emission of carbon dioxide (CO2), a principal greenhouse gas (GHGs). This paper highlights key benefits and status of bioethanol production technologies, aiming mainly on recent developments and its key potentials in Pakistan. Most sector of Pakistan economy heavily rely on the energy and power that is being produced using traditional approaches like from oil and hydel. However, the sedimentation in dams cut-down the energy generation and overwhelmed severe energy crisis that are witnessed since last decade. Thus, Pakistan must go to avail alternative sources of energy like hydro, biomass and solar so that energy security can be ensured to recover the tremendous loss of economy. Renewable biomass is abundantly available in Pakistan which can be used to produce bioethanol and electricity. Currently, 22 distilleries are producing the ethanol from sugar cane bagasse and out of these only 8 distillation units are producing motor fuel grade ethanol. The current bioethanol production of country is about 403,500 tons/year along with 2423 tons of biodegradable waste available in major cities. In addition, Pakistan produces 6.57, 0.5, 0.66, and 2.66 million tons of sugarcane, corn, rice, and wheat straw per annum, respectively. This biomass can produce 1.6 million liters of bioethanol which can produce approximately 38% of Pakistan's electricity annually. Despite having large potential, Pakistan is still producing a few volumes of ethanol from sugarcane bagasse. The production of bioethanol can be boosted using (I) pretreatment of agricultural biomass by alkali (II) enzymatic and bacteria-based hydrolysis of the biomass (III) post-hydrolysis using pressurized steam above 100 °C (IV) Fermentation of the biomass@ 7–10 h and (V) and (VI) distillation of bioethanol. This study recommends (1) increase R&D capacities mainly in the west and central regions of Pakistan, (2) initiate mega-projects to promote integrated bio-ethanol production at agriculture farms by providing 1/3 subsides, (3) purchase of bioethanol directly from the major agricultural farms, (4) produce bioethanol related manpower from the key research institutes as specified in this study.

Ranking and Evaluation of CO2 Storage Sites Using an Advanced Workflow

The world is in urgent need of carbon capture and storage (CCS) sites/facilities to achieve ambitious net carbon dioxide (CO2) emission reduction goals. After CO2 capture and transport, storage is the third step of the CO2 journey. Accessing and utilizing regional seismic information is a significant part of any workflow attempting to identify and characterize proposed subsurface CO2 storage sites. In this paper, we have developed and implemented a workflow over a proof-of-concept (PoC) area to assess CCS storage capacity and containment at a candidate saline aquifer site. Injectivity and monitoring/monitorability are assessed as part of an extended workflow. The integrated PoC CCS site assessment workflow allows validation of the various workflow elements and technologies, with the view to creating an efficient and scalable tool for regional site identification and characterization. The current project has been established using a PGS regional multi-client broadband seismic dataset in the North Sea which comprises an extensive cross-border regional dataset in the UK and Norway. The broadband nature of the seismic data allows significant and efficient site assessment, by providing detailed 3D characterization of the subsurface, away from areas with well control, and the parameterization of more accurate/reliable attributes for key storage attributes such as net-to-gross, porosity, and thickness. Finally, the integrated workflow and data integration allowed us to perform an efficient carbon storage site risk assessment as part of an overall site ranking process.

Escalating carbon emissions from North American boreal forest wildfires and the climate mitigation potential of fire management.

Wildfires in boreal forests release large quantities of greenhouse gases to the atmosphere, exacerbating climate change. Here, we characterize the magnitude of recent and projected gross and net boreal North American wildfire carbon dioxide emissions, evaluate fire management as an emissions reduction strategy, and quantify the associated costs. Our results show that wildfires in boreal North America could, by mid-century, contribute to a cumulative net source of nearly 12 gigatonnes of carbon dioxide, about 3% of remaining global carbon dioxide emissions associated with keeping temperatures within the Paris Agreement’s 1.5°C limit. With observations from Alaska, we show that current fire management practices limit the burned area. Further, the costs of avoiding carbon dioxide emissions by means of increasing investment in fire management are comparable to or lower than those of other mitigation strategies. Together, our findings highlight the climate risk that boreal wildfires pose and point to fire management as a cost-effective way to limit emissions.

Carbon Dioxide Neutralization Across the Global Supply Chain

The increased impacts of climatic change and global warming has led many organizations to adopt green initiatives in several areas of their business processes. Many multinational companies are moving towards reduction of carbon emission across its various operations. Carbon neutrality is the process where steps are taken to achieve net zero carbon dioxide emissions. This article proposes measures to achieve carbon neutrality across the supply chain globally. As part of its sustainability initiative, organizations have decided to reduce carbon consumption across their plants. This calls for estimation of carbon dioxide emissions and reducing the carbon footprint in the entire supply chain process. It also involves gauging greenhouse CO2 emissions during the transportation process for all TMC regions and transportation models used by various companies. The main calculations include total CO2 emissions, CO2 emissions per ton of goods transported, CO2 emissions per transport Km. These calculations are done based on factors such as full truck load, less truck load, sea mode of transportation, and air mode of transportation. An analysis is performed on the resulting calculation figures for different modes of transportation such as road, air, and sea. The analysis shows that there is an increase in overall CO2 for air mode of transportation. The least increase in overall Co2 is sea mode of transportation. Through this analysis, it helps the company to take better decisions regarding the mode of transportation that they need to adopt to achieve carbon neutrality.

Net carbon dioxide emissions from an eroding Atlantic blanket bog

The net impact of greenhouse gas emissions from degraded peatland environments on national Inventories and subsequent mitigation of such emissions has only been seriously considered within the last decade. Data on greenhouse gas emissions from special cases of peatland degradation, such as eroding peatlands, are particularly scarce. Here, we report the first eddy covariance-based monitoring of carbon dioxide (CO2) emissions from an eroding Atlantic blanket bog. The CO2 budget across the period July 2018–November 2019 was 147 (± 9) g C m−2. For an annual budget that contained proportionally more of the extreme 2018 drought and heat wave, cumulative CO2 emissions were nearly double (191 g C m−2) of that of an annual period without drought (106 g C m−2), suggesting that direct CO2 emissions from eroded peatlands are at risk of increasing with projected changes in temperatures and precipitation due to global climate change. The results of this study are consistent with chamber-based and modelling studies that suggest degraded blanket bogs to be a net source of CO2 to the atmosphere, and provide baseline data against which to assess future peatland restoration efforts in this region.

Improving the economics of fossil-free steelmaking via co-production of methanol

Steelmaking is responsible for 7% of the global net emissions of carbon dioxide and heavily reducing emissions from currently dominating steelmaking processes is difficult and costly. Recently, new steelmaking processes based on the reduction of iron ore with hydrogen (H2) produced via water electrolysis have been suggested. If the electricity input to such processes is fossil-free, near-zero carbon dioxide emissions steelmaking is achievable. However, the high electricity demand of electrolysis is a significant implementation barrier. A H2 storage may alleviate this via allowing a larger share of H2 to be produced at low electricity prices. However, accurately forecasting electricity market dynamics is challenging. This increases the risk of investment in a H2 storage. Here we evaluate a novel methanol-based H2 storage concept for H2-based steelmaking that also allows for the co-production of methanol. During electricity price peaks, the methanol can be reformed to produce H2 for the steelmaking process. During prolonged periods of low electricity prices, excess methanol can be produced and sold off, thus improving the prospects of storage profitability. We use historical electricity prices and a process model to evaluate methanol and fossil-free steel co-production schemes. Methanol co-production is found to have the potential to improve the economics of H2 supply to a fossil-free steelmaking process by up to an average of 0.40 €/kg H2 across considered scenarios, equivalent to a 25.0% reduction in H2 production electricity costs.

Progress in the Use of Biosourced Phenolic Molecules for Electrode Manufacturing

In the era of renewable technologies and clean processes, carbon science must adapt to this new model of a green society. Carbon materials are often obtained from petroleum precursors through polluting processes that do not meet the requirements of sustainable and green chemistry. Biomass is considered the only renewable source for the production of carbon materials, as the carbon in biomass comes from the consumption of carbon dioxide from the atmosphere, resulting in zero net carbon dioxide emissions. In addition to being a green source of carbon materials, biomass has many advantages such as being a readily available, large and cheap feedstock, as well as the ability to create unique carbon-derived structures with well-developed porosity and heteroatom doping. All these positive aspects position biomass-derived carbon materials as attractive alternatives in multiple applications, from energy storage to electrocatalysis, via adsorption and biosensors, among others. This review focuses on the application of phenolic resins to the production of electrodes for energy storage and the slow but inexorable movement from petroleum-derived phenolic compounds to biosourced molecules (i.e., lignins, tannins, etc.) as precursors for these carbon materials. Important perspectives and challenges for the design of these biosourced electrodes are discussed.