China’s construction industry-linked economy-resources-environment flow in international trade

During construction, a large number of resources are consumed; concurrently, a large amount of greenhouse gas is emitted, which contributes to air pollution. There exist close interactions among construction regions. This study examined the main economy-resources-environment indexes associated with China’s construction industry, embodied in international trade based on the Eora database, by using the input-output model. It investigated the linkages of the economy-resources-environment nexus and suggests recommendations accordingly. We found that the total amount of input consumption and output emissions in China’s construction activities increased rapidly, both locally and abroad. China pulled much more emissions from construction-related activities abroad than the latter pulled from China. The overseas regions’ dependence on China’s construction industry gradually increased. Overall, China’s construction activities accelerated the rate of foreign countries’ resource utilization and air pollution more than it did economic profits for some of these countries. The effects on countries differed. China’s construction industry was closely related to the Asian, African, and Latin American undeveloped regions. In regard to the developed regions, cooperation with Australia, the UK, Sweden and Russia was more frequent. There existed a close relationship between all the economy-resources-environment indexes. Based on the findings, protective measures were suggested, including avoiding unnecessary construction activities, optimizing China’s economic and energy use structure, improving the efficient use of resources, strengthening environmental protection both abroad and locally, as well as reducing the export of products with high energy or resources consumption.

The embodied flow of built-up land in China?s interregional trade and its implications for regional carbon balance

Qinli Lu

Built-up land intensively concentrates human activities, and its area or the changes in its intensity dramatically affect the regional carbon balance. This study proposed a new framework to assess how in China, the interregional trade?s use of built-up land affects regional carbon balance with regard to the initial maintained land and the expanded built-up land. Then, a multiregional input-output model was used to simultaneously analyse China?s built-up land flow in interregional trade and the effect on carbon balance. Finally, hidden regional inequality was analysed. The results show that the domestic trade pulled indirect external built-up land use reached to 100286 km2 in 2012 and caused 28084 ? 104 t external province pulled carbon emissions for whole China, including 286 ? 104 t from vegetation carbon storage loss. Regionally, more developed regions were always net receivers of built-up land use, in contrast, less developed regions more frequently acted as net suppliers, but most regions experienced economic and environmental deficits. The majority of other provinces experienced a contradictory status of loss of economic profit or environmental profit. For sustainable development and regional equality, more developed regions should provide more economic and technological support for effective built-up land use and emissions reduction to less developed regions.

ELSEVIER2021

Environomic modeling and optimization of advanced combined cycle cogeneration power plants including CO2 separation options

Considering the economic importance of the electricity generation sector as well as its contribution to local, regional and global pollution, the development of new cost-effective and environmentally benign electricity generation and cogeneration systems is an essential task. In this context, combined cycle cogeneration power plants are among the most promising systems. The integration of gas turbines with a steam turbine cycle leads to complex systems and to an increasing number of technological options for their improvement. Faced with growing concerns about greenhouse gas emission, systems for CO2 separation become an additional option and compete with measures for efficiency improvement. The simultaneous consideration of economic and environmental concerns as well as the increasing system complexity and the growing number of options represent an important challenge to the engineer and require the development of new approaches and design tools. The present work contributes to the development of such an approach and its application to combined cycle cogeneration power plants and their advanced options. These options, such sequential combustion gas turbines, compressor intercooling of CO2 separation can improve performance with respect to efficiency and emissions, but require increased investment costs. These competing factors are united in a so-called environomic model which takes into account the costs of resources and capital investment, as well as the costs of pollution, and calculates a single criterion – the total cost of electricity production. The costs of pollution used in this work are based on economic studies from the literature. For internalization, a penalty factor allows the degree of pollution already present in the environment to be taken into account. Benefits due to the substitution of domestic furnaces through cogeneration are also considered. A so-called "superconfiguration" model allows the modeling of simultaneous changes in configuration and design. Uncertainties linked to thermodynamic performance and investment costs model are addressed through calibration by means of reference combined cycle power plants, as well as through a proposed method for directly taking them into account in the model. The influence of varying requirements such as the power plant size, operating time and emission limits can also be modeled, providing valuable information such as thermodynamic states, component performance and investment costs. The resulting optimization problem is of the non-linear, mixed integer type. The complex task of finding optimum solutions is accomplished by means of powerful optimization methods that allow searching of the entire solution space. In this work, a genetic algorithm was adapted to the requirements of the superconfiguration optimization, permitting the simultaneous optimization of configuration and design. Genetic algorithms work with populations instead of a single data point and rely on biological mechanisms such as mating, mutation and replacement, and provide multiple promising solutions. Reference cases with different electricity and heat demand as well as different annual operating time are optimized and analyzed in detail with respect to the solutions obtained. Based on these reference cases, sensitivity studies on the cost of pollution, as well as emission limits, show the influence of these factors on the combined cycle configuration and design, as well as on the cost structure of electricity, and demonstrate an application of the method.

EPFL1998

Multiobjective Optimisation of integrated energy systems for remote communities considering economic and CO2 emissions

Daniel Favrat, Geoffrey Basil Leyland, Xavier Pelet

The methods for designing, planning and managing integrated energy systems, while holistically considering the major economic and environmental factors, are still embryonic. However, the first phase of the design is often crucial if we want to manage resources better resource and reduce energy consumption and pollution. Considering integrated energy systems implies dealing with complex systems in which the synergy between the various components is best exploited (for example the thermal energy of a diesel engine produced during the night is complimented by the Ranking Organic Cycle of a solar thermal plant). The context of isolated communities further increases the difficulties when considering the long distance of transport required to supply fossil fuels. These sites are often located in very precarious environments, with limited or nonexistent resources except for solar energy, and with frequent additional needs for desalination (in arid zones). This paper illustrates a holistic method to rationalize the design of energy integrated systems. It is based on a superstructure (collection of models of all envisaged technologies) and a multi-objective optimisation (resources, demand, energy, emission, cost) using an evolutionary algorithm. The approach proposed allows the identification of more complete and more coherent integrated configurations characterizing the most promising designs (also taking into account the time dependency aspects). It also allows to better structure the information in view of a participative decision approach. The study shows that the economic implementation of renewable energy (solar) is even more difficult, compared to Diesel based solutions, in cases of isolated communities with high load variations. New infrastructure or retrofit cases are considered.

2005

Environomic modeling and optimization of advanced combined cycle cogeneration power plants including CO2 separation options

EPFL1998