Carbon Sequestration Projects Research Articles

Potential technical hazards associated with four North American carbon capture and sequestration projects

Carbon capture and storage (CCS) risks depend upon the site geology, potential CO2-caprock reactions, anthropogenic pathways (legacy wellbores), and well construction and operation. Herein, we asse...

Farmers' preferred tree species and their potential carbon stocks in southern Burkina Faso: Implications for biocarbon initiatives.

The success of terrestrial carbon sequestration projects for rural development in sub-Saharan Africa lies in the (i) involvement of local populations in the selection of woody species, which represent the biological assets they use to meet their daily needs, and (ii) information about the potential of these species to store carbon. Although the latter is a key prerequisite, there is very little information available. To help fill this gap, the present study was undertaken in four pilot villages (Kou, Dao, Vrassan and Cassou) in Ziro Province, south-central Burkina Faso. The objective was to determine carbon storage potential for top-priority woody species preferred by local smallholders. We used (i) participatory rural appraisal consisting of group discussions and key informant interviews to identify priority species and functions, and (ii) landscape assessment of carbon stocks in the preferred woody species. Results revealed 79 priority tree and shrub species grouped into six functions, of which medicine, food and income emerge as the most important ones for the communities. For these functions, smallholders overwhelmingly listed Vitellaria paradoxa, Parkia biglobosa, Afzelia africana, Adansonia digitata, Detarium microcarpum, and Lannea microcarpa among the most important tree species. Among the preferred woody species in Cassou and Kou, the highest quantity of carbon was stored by V. paradoxa (1180 ±209 kg C ha-1 to 2089±522 kg C ha-1) and the lowest by Grewia bicolor (5±1.2 kg C ha-1). The potential carbon stored by the preferred tree communities was estimated at 587.9 Mg C ha-1 (95% CI: 456.7; 719.1 Mg C ha-1) in Kou and256.8 Mg C ha-1 (95% CI: 67.6; 324.4 Mg C ha-1) in Cassou. The study showed that the species that farmers preferred most stored more carbon than species that were less preferred.

Influence of rural households' livelihood capital on income derived from participation in the Forest Carbon Sequestration Project: a case from the Sichuan and Yunnan Provinces of China

We analyze survey data collected from interview of 367 randomly selected rural households from the Sichuan and Yunnan provinces of China to assess the influence of rural households' livelihood capital (physical, financial, human, natural, and social capital) on their income from participation in the forest carbon sequestration project. The project is implemented under the Climate, Community, and Biodiversity standards. Results show that, with regional differences controlled, natural capital and physical capital have a positive and statistically significant influence, whereas the human capital, financial capital, and social capital of rural households have a negative and statistically significant influence on their income from participation in the project.

Analysis of factors influencing forest carbon sequestration project in Guangdong Province and recommendations.

Analysis of factors influencing forest carbon sequestration project in Guangdong Province and recommendations.

Economic benefit of carbon sequestration project of CCER bamboo forest management in Anji County, Zhejiang Province

Based on The Bamboo Forest Management Carbon Sequestration Project Methodology and improved project economic benefit evaluation model, this research conducted a quantitative evaluation of the economic benefits of CCER bamboo forest management carbon sequestration project and analyzed the sensitivity of the net present value under different scenarios. The results showed that the net present value of bamboo forest management carbon sequestration project was 195.675 2 million yuan in total, 6.522 5 million yuan per year and 137 200 yuan per hectare under the current market conditions, which was 42.05 per cent higher than that of the traditional bamboo forest management. Total carbon dioxide emission reduction was 249 658 t; the average annual emission reduction was 8 322 t; the amount of emission reduction per hectare was 175 t·hm-2. The net present value of the project emission reduction was 4.654 0 million yuan in total, 155 100 yuan per year and 3 300 yuan per hectare. The degree of sensitivity of the net present value of the project was bamboo price > discount rate > labor price > carbon price in the same rate of change scenarios. On the basis of the research findings, the relevant suggestions were put forward from three perspectives, namely, carbon price, farmer's income, and market environment, to carry out bamboo forest management carbon sequestration project better.

Prediction of Rural Women Empowerment receiving Microcredits through Carbon Sequestration Project (CSP) in South Khorasan Province (Iran)

One of the goals of the International Carbon Sequestration Project in South Khorasan Province is to study the sustainability of natural resources, especially in the rehabilitated areas, by reducing the reliance of villagers to the natural resources of the region, creating alternative livelihoods with job empowerment and solving the problems of villagers in the region, especially rural women. The purpose of this study was to predict the rural women’ empowerment who received microcredits during the project. The research was done through a descriptive-correlational method. Statistical sample includes 188 rural women who were members of the microcredit Fund. The validity of the questionnaire was confirmed by panel of research committee experts and the reliability was confirmed by calculating Cronbach's alpha coefficient to 0.95. The results of study showed that there is positively a significant correlation between rural women empowerment and variables of Membership Years, Loan Amount, and Loan adequacy, Age, Literacy Level and Income per month. But rural women empowerment could be predicted by three variables of Loan adequacy, Literacy Level and women Age. Also, Loan adequacy was known as the most powerful predictor of rural women empowerment. Given the positive impact of microcredits on rural women empowerment, as well as rural women empowerment to reduce pressure on ecosystems and improve carbon sequestration, it is proposed to increase the microcredit program and its amount.

Acculturation of rural households participating in a clean development mechanism forest carbon sequestration program: A survey of Yi ethnic areas in Liangshan, China

We present results from a survey of rural households of the Yi people that participated in the clean development mechanism forest carbon sequestration project in Liangshan, Sichuan, China. We analyze rural households’ acculturation strategies and the corresponding influencing factors of local traditional culture and modern commercial culture with forestation and a reforestation carbon sequestration project based on two dimensions and four strategies, viz., integration, assimilation, separation, and marginalization. Results indicate that rural households that took part in the forest carbon sequestration project had a higher identification with local traditional culture than with modern commercial culture. Integration and separation were two primary adaptation strategies toward traditional culture and modern commercial culture. Gender, age, education level, and land area involved in the project were significant determinants for rural households’ cultural adaptation strategies.

Transport of perfluorocarbon tracers in the Cranfield Geological Carbon Sequestration Project

AbstractA field‐scale carbon dioxide (CO2) injection pilot project was conducted by the Southeast Regional Carbon Sequestration Partnership (SECARB) at Cranfield, Mississippi. Two associated campaigns in 2009 and 2010 were carried out to co‐inject perfluorocarbon tracers (PFTs) and sulfur hexafluoride (SF6) with CO2. Tracers in gas samples from two observation wells were analyzed to construct breakthrough curves. In this work, we present the field data and numerical modeling of the flow and transport of CO2, brine, and tracers. A high‐resolution static model of the formation geology in the detailed area study (DAS) was used to capture the impact of connected flow pathways created by fluvial channels on breakthrough curves and breakthrough times of PFTs and SF6 tracers. We use the cubic‐plus‐association (CPA) equation of state, which takes into account the polar nature of water molecules, to describe the phase behavior of CO2–brine‐tracer mixtures. Our simulated results show good agreement for the 2009 tracer campaign in Cranfield, while a larger discrepancy emerges by 2010. The combination of multiple tracer injection pulses with detailed numerical simulations proves to be a powerful tool in constraining both formation properties and how complex flow paths develop over time. © 2018 Society of Chemical Industry and John Wiley & Sons, Ltd.

Tax incentives expected to drive growth of CO2 capture

A small provision in legislation that passed last month to increase U.S. government spending limits is predicted to trigger an explosion of new spending for carbon capture and sequestration (CCS) projects. The provision creates a tax credit based on tonnage of carbon dioxide captured and sequestered underground or used in some way and kept out of the atmosphere. For those who claim the credit, this benefit will increase over time, topping out at $50 per metric ton in 2026. Congress agreed to the provision with support from an unlikely combination of fossil-fuel advocates and lawmakers concerned about climate change. The policy is intended to drive down costs for capturing and sequestering the greenhouse gas emitted from power plants, refineries, and other industrial sources as well as for stripping CO2 from ambient air. At the national meeting of the Global CCS Institute on March 13, speakers predicted these tax incentives would

Cost-optimal design of pressure-based monitoring networks for carbon sequestration projects, with consideration of geological uncertainty

Leakage from geologic faults and abandoned wells represents one of the major risks to industrial-scale carbon capture and storage (CCS) projects. Current CCS regulations and best practice guidance suggest that operators emplace risk-informed monitoring, verification, and accounting (MVA) plans to protect public safety and reduce property and environmental damage. Deep subsurface pressure monitoring is regarded as one of the most cost-effective technologies for early leakage detection in CCS projects. In practice, however, the number of deep pressure monitoring wells that an operator can deploy often remains limited because of the high costs associated with drilling, instrumenting, and operating these wells. Thus, optimal design of the pressure monitoring network is essential to minimizing monitoring and liability costs and gaining public support. In this work, we present a general, binary integer programming approach to solve an optimal monitoring well network design problem under multiple constraints. Specifically, our approach helps a CCS operator to design a cost-optimal monitoring network that covers all potentially leaky locations (in a worst-case-scenario sense) while satisfying a prescribed carbon dioxide (CO2) storage performance criterion and considering geological uncertainty. Instead of using cost surrogates as has been done in many other studies, our formulation allows the user to directly assess total costs in terms of monitoring costs and potential economic losses associated with brine and CO2 leakage. Our numerical examples demonstrate that a cost-optimal monitoring network may save millions of dollars in total costs, including well construction and leakage costs. Factors exerting the most impact on the cost-optimal monitoring network design are unit leakage damage costs, pressure threshold for leakage detection, and geological uncertainty.

Variation of Contact Angles in Brine/CO2/Mica System considering Short-Term Geological CO2 Sequestration Condition

Geological CO2 sequestration has been proposed as an effective solution to mitigate excessive human-emitted CO2 in atmosphere. Knowledge of immiscible two-phase flow of CO2-water/brine is necessary to evaluate the efficiency and safety of geological storage sites. Among forces dominating fluid flow, capillary pressure is highly important because of high uncertainty in measurement due to ambiguous wettability behavior of geomaterials. In particular, time-dependent wettability of geomaterials is of interest for predicting short-term performance of the storage site. After injection of CO2 into an aquifer, both the CO2 and water/brine in rocks pores are unsaturated and tend to dissolve into each other. Present study investigates the variation of contact angle on mica sheet using a captive bubble method at a wide range of pressures and salinities under unsaturated condition. Our results showed a general increase of contact angle with time. Comparison of unsaturated contact angle with previous results in the literature showed a wide span of wettability behavior, ranging from receding to advancing contact angle values reported in the literature. The observed decrease in wettability by time due to heterogeneity and pinning effect of triple line can jeopardize the safety of geological carbon sequestration projects in short-term after injection of CO2.

Effects of the distribution and evolution of the coefficient of friction along a fault on the assessment of the seismic activity associated with a hypothetical industrial-scale geologic CO2 sequestration operation

Carbon capture and storage (CCS) in geological formations is considered as a promising option that could limit CO2 emissions from human activities into the atmosphere. However, there is a risk that pressure buildup inside the storage formation can induce slip along preexisting faults and create seismic event felt by the population. To prevent this to happen a geomechanical fault stability analysis should be performed, considering uncertainties of input parameters. In this paper, we investigate how the distribution of the coefficient of friction and the applied frictional law could influence the assessment of fault stability and the characteristics of potential injection-induced seismic events. Our modelling study is based on a hypothetical industrial-scale carbon sequestration project located in the Southern San Joaquin Basin in California, USA, where the stability on a major (25km long) fault that bounds the sequestration site is assessed during 50 years of CO2 injection. We conduct nine simulations in which the distributions of the coefficients of static and dynamic friction are changed to simulate a hardening and softening phase before and during rupture. Our main findings are: (i) variations in friction along the fault have an important effect on the predicted seismic activity, with maximum magnitude ranging from 1.88 to 5.88 and number of seismic events ranging from 338 to 3272; (ii) the extreme values of the coefficient of friction (lowest and highest) present along the rupture area control how much stress is accumulated before rupture; and (iii) an argillaceous caprock can prevent the development of large magnitude seismic events but favor the occurrence of a large number of smaller events.

Evaluating the Situation of Environmental Culture’s Reproduction in Rural Areas (Case Study: A Pilot of Carbon Sequestration Project in Jazmourian)

Evaluating the Situation of Environmental Culture’s Reproduction in Rural Areas (Case Study: A Pilot of Carbon Sequestration Project in Jazmourian)

Multi-temporal mesoscale hyperspectral data of mixed agricultural and grassland regions for anomaly detection

Flight-based hyperspectral imaging systems have the potential to provide valuable information for ecosystem and environmental studies, as well as aid in land management and land health monitoring. This paper examines a series of images taken over the course of three years that were radiometrically referenced allowing for quantitative comparisons of changes in vegetation health and land usage. The study area is part of a geologic carbon sequestration project located in north-central Montana, approximately 580ha in extent, at a site requiring permission from multiple land owners to access, making ground based validation difficult. Classification based on histogram splitting of the biophysically based parameters utilizing the entire three years of data is done to determine the major classes present in the data set in order to show the constancy between data sets taken over multiple years. Additionally, a method of anomaly detection for both single and multiple data sets, using Median Absolute Deviations (MADs), is presented along with a method of determining the appropriate size of area for a particular ecological system. Detection of local anomalies within a single data set is examined to determine, on a local scale, areas that are different from the surrounding area and depending on the specific MAD cutoff between 50–70% of the anomalies were located. Additionally, the detection and identification of persistent (anomalies that occur in the same location over multiple data sets) and non-persistent anomalies was qualitatively investigated.

Development and evaluation of the coaxial cable casing imager: a cost‐effective solution to real‐time downhole monitoring for CO2 sequestration wellbore integrity

AbstractCO2 leakage is a major concern in a geological carbon sequestration projects due to adverse environmental consequences, where the main leakage risk is identified to be along existing wells through a thick, low‐permeable cap rock. To pursue robust and cost effective real‐time downhole monitoring technology for CO2 sequestration wellbore integrity, a permanently deployed coaxial cable casing imager is developed and evaluated in laboratory in this paper. The prototype of the casing imager consists of evenly distributed coaxial cable strain sensors helically wrapped around the pipe. The system is deployed on both PVC pipe and steel pipe to test its performance in casing deformation monitoring, including axial compression, radial expansion, bending, and ovalization. The strain sensors are pre‐stressed and then helically wrapped onto the pipe with high strength epoxy. Multiple linear variable differential transformers (LVDTs) or strain gauges are used as an independent measurement of the actual pipe deformation in comparison to the casing imager measured pipe deformation. The test results demonstrated the ability of the lab‐scale casing imager prototype in real‐time casing deformation monitoring, including axial compression, radial expansion, bending, and ovalization, which would prove of great value in evaluating wellbore integrity state and providing early warnings of leakage risk that will contaminate the groundwater during CO2 injection. The low cost and high robustness of the distributed coaxial cable sensors will greatly lower the downhole monitoring cost and increase the system longevity. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

The Role of Combating Desertification Projects in Promotion of Local People’s Social Capital (The Case of Shahdad Carbon Sequestration Project)

مطالعه حاضر با هدف بررسی نقش پروژه ترسیب کربن در بهبود سرمایه اجتماعی مردم محلی تحت پوشش پروژه در منطقه شهداد استان کرمان انجام شد. جامعه آماری تحقیق حاضر شامل اعضای گروه‌های توسعه روستاهای تحت پوشش پروژه ترسیب کربن به تعداد 456 نفر و مردم محلی شش روستای خارج از پروژه ترسیب کربن به تعداد 1428 نفر بود. حجم نمونه براساس جدول کرجسی و مورگان 218 نفر تعیین شد. برای مقایسه، همین تعداد نمونه از بین مردم محلی خارج از پروژه انتخاب شد. نمونه‌ها به روش نمونه‌گیری تصادفی طبقه‌ای با انتساب متناسب انتخاب شدند. پرسش‌نامه ابزار اصلی جمع‌آوری داده‌ها بود. روایی محتوایی این پرسش‌نامه را اساتید رشته ترویج و آموزش کشاورزی و کارشناسان ستادی و صفی طرح ترسیب کربن در سازمان جنگل‌ها، مراتع و آبخیزداری کشور تأیید کردند. برای تعیین پایایی پرسش‌نامه از ضریب آلفای کرونباخ استفاده و مقدار آن برای بخش‌های مختلف پرسش‌نامه بین 70/0 تا 90/0 محاسبه شد. با توجه به نتایج تحقیق، بین سرمایه اجتماعی مردم محلی تحت پوشش پروژه در قبل و بعد از اجرای طرح اختلاف معنی‌دار وجود دارد. همچنین بین سرمایه اجتماعی مردم محلی تحت پوشش پروژه و خارج از پوشش پروژه نیز اختلاف معنی‌دار وجود دارد. در مجموع می‌توان گفت پروژه ترسیب کربن بر سرمایه اجتماعی مردم محلی که شرط لازم برای توسعه اجتماعی محسوب می‌شود تأثیر مثبت داشته است.

Effect of Exclosure Age on Carbon Sequestration Potential of Restorations in Tigray Region, N. Ethiopia

Conversion of degraded free grazing lands into exclosures is one option to promote natural regeneration of plants and to restore degraded ecosystems in Ethiopia. The present study investigated the change in ecosystem carbon stocks (ECS) and the enhancement of plant species richness and diversity following the establishment of exclosures on free grazing lands in Tigray, Ethiopia. Exclosures of 10, 15, and 20 years old were selected and each exclosure was paired with an adjacent free grazing land. A total of 120 quadrants were sampled using a stratified preferential sampling design technique with flexible systematic model. The differences in carbon stocks and vegetation composition between an exclosure and free grazing lands were assessed using a paired t-test. Data analyses also included descriptive statistics, inferential statistics using one way ANOVA, t-test and Chi-square test. All exclosures displayed higher ECS, and plant species richness, diversity and aboveground standing biomass than the free grazing lands. Differences in ECS between exclosures and free grazing lands varied between 32.96 and 61.0 t. ha^-1 increasing with exclosure age. Over a period of 20 years, the carbon dioxide sequestered in the investigated exclosures was 223.88 t. ha^-1. Differences in plant species richness and aboveground standing biomass between exclosures and free grazing lands also increased with exclosure age. The results of the present study confirm that establishment of exclosures on degraded free grazing lands in the Northern Highlands of Ethiopian is a viable option to restore ECS. The study showed that ECS in exclosures, in free grazing lands and the change in ECS following the establishment of exclosures on free grazing lands can be predicted using easily measurable biophysical and management-related indicators. Such information is necessary for the establishment of baseline information for carbon sequestration projects, for evaluation of whether exclosure establishment should be expanded, and for policymakers to take into account the value of exclosures in their management decisions. Although the study showed that exclosures are effective to restore ECS, expansion of exclosures would increase grazing pressure on the remaining free grazing area. Therefore, the decision to establish additional exclosures should also include an economical analysis and an evaluation of the social consequences of such a decision.

THE OPTIMAL ROTATIONS OF GMELINA STAND ON TWO CARBON PROJECTS: LENGTHENING ROTATION AND AFFORESTATION

Forest plantation may contribute economically and socially as a provider of wood raw materials for industry and providing jobs for local people. In addition, forest plantation may also contribute as watershed protection and carbon sequestration. Projects on carbon sequestration from plantation forest can be conducted in two types: (1) afforestation and (2) lengthening forest rotation. One of the potential carbon markets operationalized in the field is voluntary market with Verified Carbon Standard mechanism. This study aimed to analyze the optimal rotations of gmelina forests on two carbon projects: lengthening rotation and afforestation. The method used in this study was by using Hartman model ( i.e. Faustmann) by maximizing profit with the revenue source from timber and carbon sequestration project. The results of this study showed that carbon price will affect the optimal rotation for lengthening forest rotation of VCS project. Meanwhile, for VCS afforestation project, carbon price had no effect on the optimal rotation on gmelina forest. The NPV value of afforestation project was relatively higher than that of NPV value of lengthening forest rotation project, since the amount of carbon that can be credited relatively higher in afforestation project.

Simulating the Cranfield geological carbon sequestration project with high-resolution static models and an accurate equation of state

A field-scale carbon dioxide (CO2) injection pilot project was conducted as part of the Southeast Regional Sequestration Partnership (SECARB) at Cranfield, Mississippi. We present higher-order finite element simulations of the compositional two-phase CO2-brine flow and transport during the experiment. High-resolution static models of the formation geology in the Detailed Area Study (DAS) located below the oil-water contact (brine saturated) are used to capture the impact of connected flow paths on breakthrough times in two observation wells. Phase behavior is described by the cubic-plus-association (CPA) equation of state, which takes into account the polar nature of water molecules. Parameter studies are performed to investigate the importance of Fickian diffusion, permeability heterogeneity, relative permeabilities, and capillarity. Simulation results for the pressure response in the injection well and the CO2 breakthrough times at the observation wells show good agreement with the field data. For the high injection rates and short duration of the experiment, diffusion is relatively unimportant (high Péclet numbers), while relative permeabilities have a profound impact on the pressure response. High-permeability pathways, created by fluvial deposits, strongly affect the CO2 transport and highlight the importance of properly characterizing the formation heterogeneity in future carbon sequestration projects.

Effects of in situ stress measurement uncertainties on assessment of predicted seismic activity and risk associated with a hypothetical industrial-scale geologic CO2 sequestration operation

Carbon capture and storage (CCS) in geologic formations has been recognized as a promising option for reducing carbon dioxide (CO2) emissions from large stationary sources. However, the pressure buildup inside the storage formation can potentially induce slip along preexisting faults, which could lead to felt seismic ground motion and also provide pathways for brine/CO2 leakage into shallow drinking water aquifers. To assess the geomechanical stability of faults, it is of crucial importance to know the in situ state of stress. In situ stress measurements can provide some information on the stresses acting on faults but with considerable uncertainties. In this paper, we investigate how such uncertainties, as defined by the variation of stress measurements obtained within the study area, could influence the assessment of the geomechanical stability of faults and the characteristics of potential injection-induced seismic events. Our modeling study is based on a hypothetical industrial-scale carbon sequestration project assumed to be located in the Southern San Joaquin Basin in California, USA. We assess the stability on the major (25 km long) fault that bounds the sequestration site and is subjected to significant reservoir pressure changes as a result of 50 years of CO2 injection. We present a series of geomechanical simulations in which the resolved stresses on the fault were varied over ranges of values corresponding to various stress measurements performed around the study area. The simulation results are analyzed by a statistical approach. Our main results are that the variations in resolved stresses as defined by the range of stress measurements had a negligible effect on the prediction of the seismic risk (maximum magnitude), but an important effect on the timing, the seismicity rate (number of seismic events) and the location of seismic activity.