Needed: a price for carbon capture

Facing the global climate change crisis, many cities have proposed the goal to achieve net-zero carbon cities. The natural carbon sink in urban space is indispensable for net-zero carbon cities, but the existing measurement system has shortcomings in the measurement elements and precision. This leads to unclear control objectives and elements of spatial planning, and the relevant planning strategies lack the support of quantitative results. We included the often-ignored natural carbon sink space and soil in the measurement scope. Taking Hangzhou as an example, we built a natural carbon sink capacity measurement system with respect to the carbon sequestration and storage capacity, measured the natural carbon sink, and evaluated its carbon neutrality’s contribution in urban space. The results showed that the carbon sink capacity of soil and small green spaces in built-up areas could affect the quantity and spatial pattern of the measurement results. Both should be included in the measurement system to improve corresponding spatial planning strategies’ reliability and feasibility. Additionally, Hangzhou’s annual natural carbon sequestration offset approximately 9.87% of the carbon emissions in the same year. With respect to the contribution to carbon neutrality, the role of natural carbon sinks in urban space was necessary, but the effect was limited. Therefore, strategies to reduce carbon emissions are integral for the net-zero carbon goal. Some spatial planning strategies to improve the urban natural carbon sink capacity are discussed. A more precise and comprehensive understanding of the urban natural carbon sink capacity can support the construction of a net-zero carbon city better.

Surplus or deficit? Quantification of carbon sources and sinks and analysis of driving mechanisms of typical oasis urban agglomeration ecosystems

The impact of policies on profit-maximizing rates of reliance on carbon capture for storage versus cleaner production

Renewable energy and carbon capture and sequestration for a reduced carbon energy plan: An optimization model

Climate sensitivity in its most basic form is defined as the equilibrium change in global surface temperature that occurs in response to a climate forcing, or externally imposed perturbation of the planetary energy balance. Within this general definition, several specific forms of climate sensitivity exist that differ in terms of the types of climate feedbacks they include. Based on evidence from Earth's history, we suggest here that the relevant form of climate sensitivity in the Anthropocene (e.g. from which to base future greenhouse gas (GHG) stabilization targets) is the Earth system sensitivity including fast feedbacks from changes in water vapour, natural aerosols, clouds and sea ice, slower surface albedo feedbacks from changes in continental ice sheets and vegetation, and climate–GHG feedbacks from changes in natural (land and ocean) carbon sinks. Traditionally, only fast feedbacks have been considered (with the other feedbacks either ignored or treated as forcing), which has led to estimates of the climate sensitivity for doubled CO2 concentrations of about 3°C. The 2×CO2 Earth system sensitivity is higher than this, being ∼4–6°C if the ice sheet/vegetation albedo feedback is included in addition to the fast feedbacks, and higher still if climate–GHG feedbacks are also included. The inclusion of climate–GHG feedbacks due to changes in the natural carbon sinks has the advantage of more directly linking anthropogenic GHG emissions with the ensuing global temperature increase, thus providing a truer indication of the climate sensitivity to human perturbations. The Earth system climate sensitivity is difficult to quantify due to the lack of palaeo‐analogues for the present‐day anthropogenic forcing, and the fact that ice sheet and climate–GHG feedbacks have yet to become globally significant in the Anthropocene. Furthermore, current models are unable to adequately simulate the physics of ice sheet decay and certain aspects of the natural carbon and nitrogen cycles. Obtaining quantitative estimates of the Earth system sensitivity is therefore a high priority for future work.

A review of atmospheric carbon dioxide sequestration pathways; processes and current status in Nigeria

At least for two decades, various techniques have been developed to solve the greenhouse gas emissions problem. The carbon capture and storage (CCS) technology is the main solution to reduce carbon dioxide emissions from the industrial sector and power plant. CCS involves the capture of CO2 emissions from an exhaust gas, transporting and storing in geological storage. All of these CCS activities give several planning problems related to geographical conditions that may be an archipelago country, a considerable distance between the CO2 sources and sinks, and the difference in time of CO2 capturing and injecting to storage. The process integration technique by pinch design method can be used for CCS networks. This paper presents an application of pinch design method for CCS networks in central parts of Indonesia. The integration of carbon incentive and carbon tax is proposed to evaluate the value of CCS networks. The effect of time difference between sources and sinks on the amount of CO2 uncaptured was considered to assess the sensitivity of CCS project’s value. The results showed that the combination of pinch design method with the carbon trading and carbon tax provided a potential method to assess the effectiveness of CCS networks.

Carbon capture and utilization: More than hiding CO2 for some time

In this study, the effect of slurry concentration and carbon dioxide capture and storage (CCS) equipment on the techno-economic feasibility of a coal-to-methanol (CTM) process with coal water slurry (CWS) gasification are investigated, while the effective means to improve the economic benefit of methanol factory are proposed. The sensitive factors including production scale, coal price, and carbon tax are investigated, especially the CWS concentration is compared at 63% and 68% scenarios. A CTM plant with 180 × 104 t/a production scale shows that the saving cost could reach 29.20 × 106 US$ and the CO2 emission could be reduced by 0.65 × 106 t/a every year as the CWS concentration increases. The investment in CCS equipment would increase the production cost (PC) per methanol raising by 7–8%, while the CCS introduction would effectively alleviate the PC increment caused by the carbon tax. Note that as the carbon tax exceeded 9.42 US$/t, the benefit for CCS on the reduction of PC would be more significant. The outcomes of this study have suggested that increasing the CWS concentration is an effective method to reduce the PC and improve the economic benefit. The CCS technology could effectively reduce CO2 emissions and mitigate the raising of PC caused by carbon tax. The findings have manifested a well feasibility for environment benefit improvement by solid content increasing and CCS introduction in response to energy and environmental challenges for the cleaner production and sustainable development.

As part of its plan to transition to an energy secure and environmentally sustainable future, Canada has had a national carbon pricing system since 2019. When first introduced, the $20 (‘$’ refer to Canadian dollars (CAD) in this paper) per tonne price was widely accepted by most Canadians and seen as a way of helping Canada meet its emissions reduction pledges made at the 2015 United Nations Climate Change Conference (COP 21) in Paris. The Canadian system is novel in that it both charges consumers for their emissions and reimburses them for their expected emissions; this is intended to raise awareness of their emissions and encourage those who can afford to opt for lower-emissions energy services to do so. By 2023, the combination of the carbon price reaching $65 per tonne and the post-pandemic economic slowdown was seized on by numerous politicians as a way of pushing back against the carbon pricing system, with most demanding the entire system be scrapped. The debate intensified in late 2023 and into 2024, when the federal government removed the carbon tax on home heating oil because the reimbursement was insufficient to cover the cost of the tax. In this paper, we consider the recent actions of two Canadian provinces, Saskatchewan and Nova Scotia, embroiled in the federal carbon pricing system debate due to the removal of the carbon tax on fuel oil for space heating. The objective of this paper is to identify how some of the reasons, including global post-pandemic inflation and other challenges facing Canadians, such as those cited in third-party polls, have contributed to a rise in the system’s unpopularity. Our method estimates and compares the impacts of the carbon tax on the household energy services for space and water heating, lighting and appliances, and private (i.e., household) transportation for different types of housing (apartment, single-attached, and single-detached) and number of occupants (two, three, and four) in Saskatchewan and Nova Scotia. The results of this work show that while Saskatchewan households have higher energy intensities than those in Nova Scotia, the impact of the carbon tax on Nova Scotians using fuel oil for heating was greater than in Saskatchewan. In Saskatchewan and Nova Scotia, natural gas and electricity, respectively, are used for heating. This paper concludes with a summary of our findings and potential options for improving perceptions of the system.

Background: A techno-economic analysis has been performed for a coal-fired power plant retrofitted with solvent-based post-combustion carbon capture (PCC) technology where thermal energy is partially supplied by solar thermal collectors. The plant is compared with a generic PCC plant where all the thermal energy is provided by steam bled from the steam cycle. A suite of solar thermal collectors which include flat plate collectors, compound parabolic collectors, linear Fresnel collectors, evacuated tube collectors (ETCs) and parabolic trough collectors (PTCs) have each been tested for their viability. The plant has been simulated for several different locations in Australia: Sydney, Townsville and Melbourne. Objectives: This study investigates the integration of solar thermal energy in the energy mix of a power plant by using it to partially compensate for the debilitating energy penalty burdened by the introduction of the carbon capture process. Methods: The overall system consists of three subsystems: power plant, PCC plant and solar collector field. A base case scenario is studied in which there is no heat integration between the three subsystems and is compared to a system with heat integration. Additionally, incentives such as renewable energy certificates (RECs), carbon tax/credits and government subsidies have been considered in the economic model and a sensitivity analysis has been performed for each scenario of incentives for all five solar collector technologies at the three locations. Results: The ETC is found to be the best performer amongst solar collectors when the three subsystems have good heat integration while the PTC is the best performer in the case of no heat integration. The best location for the solar-assisted PCC (SPCC) plant is found to be Sydney. Conclusions: The SPCC plant is only economically viable in Sydney and Townsville once incentives such as RECs, carbon tax and subsidies are taken into account. By the use of solar energy and the available government incentives for their deployment, the cost of carbon capture is shown to be reduced.

An approach to the evaluation and management of natural carbon sinks: From plant species to urban green systems

Will blue hydrogen lock us into fossil fuels forever?

Carbon Capture and Storage (CCS) euphoria is turning the oil and gas operations upside down, without having any perceptible impact on atmospheric carbon dioxide (CO2) that continues to increase. It is intended to show that the current CCS regimen has serious technical and fiscal constraints, and questionable validity. Carbon Capture, Storage, and Utilization (CCUS) is also discussed briefly. There is ample data to show that the CO2 concentration in the atmosphere is unrelentingly increasing, and the annual global CCS is about 0.1% of the 40 billion tonnes emitted. As much as 30% of the carbon dioxide captured is injected/re-injected into oil reservoirs for oil production and is not CCS at all. Several CCS methods are being tested, and some are implemented in dedicated plants in the world. A number of impediments to CO2 capture are identified and limited remedies are offered. It is shown that the problem is so gigantic and has so many dimensions that limited solutions have little efficacy. For example, about one-half of the world's population lives at less than $5 a day and has no recourse to CCS technologies. Major facets of the CCS problem are: (1) Validity of the future atmospheric CO2 concentrations based on the 100+ climate models for global warming. This is not the main discussion but is touched upon. (2) Impact of the desired CO2 concentrations on coal, oil, and gas production. (3) Principal CCS methodologies, including Direct Air Capture. (4) CCS vis-à-vis carbon tax, carbon credits, and carbon trading. (5) CCS subsidies – Is CSS workable without subsidies? At this time, No. The current tax credits for CCUS do not make sense. Finally, attention is given to CCS on a world scale – showing that so long as the great disparities in the living standards exist, CCS cannot be achieved to any significant level. All of the above is seen against the backdrop of oil and gas production and achieving Net Zero. It is shown that globally CCS has not increased beyond ∼0.1% of the global CO2 emissions in the past 20 years. The problem is that in CCS, there is injection only, no production! The paper offers partial solutions and concludes that oil and gas will continue to be energy sources far beyond the foreseeable future, and oil companies will accomplish the needed CSS.

Optimal deployment of renewable electricity technologies in Iran and implications for emissions reductions