Valorization of Agricultural Residues for Hydrogen-Based Electricity Generation towards Circular Bioeconomy

Global crises, notably climate shocks, degraded ecosystems, and growing energy demand, enforce sustainable production and consumption pathways. A circular bioeconomy offers the opportunities to actualize resource and eco-efficiency enhancement, valorization of waste streams, reduction of fossil energy and greenhouse gas (GHG) emissions. Albeit biomass resources are a potential feedstock for bio-hydrogen (bio-H2) production, Ghana’s agricultural residues are not fully utilized. This paper examines the economic and environmental impact of bio-H2 electricity generation using agricultural residues in Ghana. The bio-H2 potential was determined based on biogas steam reforming (BSR). The research highlights that BSR could generate 2617 kt of bio-H2, corresponding to 2.78% of the global hydrogen demand. Yam and maize residues contribute 50.47% of the bio-H2 produced, while millet residues have the most negligible share. A tonne of residues could produce 16.59 kg of bio-H2 and 29.83 kWh of electricity. A total of 4,705.89 GWh of electricity produced could replace the consumption of 21.92% of Ghana’s electricity. The economic viability reveals that electricity cost is $0.174/kWh and has a positive net present value of $2135550609.45 with a benefit-to-cost ratio of 1.26. The fossil diesel displaced is 1421.09 ML, and 3862.55 kt CO2eq of carbon emissions decreased corresponding to an annual reduction potential of 386.26 kt CO2eq. This accounts for reducing 10.26% of Ghana’s GHG emissions. The study demonstrates that hydrogen-based electricity production as an energy transition is a strategic innovation pillar to advance the circular bioeconomy and achieve sustainable development goals.

Study on the Construction of Circular Economy Development System of Agriculture and Animal Husbandry in Tibet

As a basic industry in Tibet Autonomous Region,the development of agriculture and animal husbandry circular economy is of great practical significance,which is actively reflected in national high-quality development and new agriculture and animal husbandry circular model.The development direction and future trend directly determine the promotion and enhancement of regional agriculture and animal husbandry economy,which is highly valued and welcomed by academic circles.This paper mainly expounds the development connotation of agriculture and animal husbandry circular economy system from the perspective of Tibet's agriculture and animal husbandry economic development.It focuses on sorting out the construction and future direction of circular economy development system,effectively puts forward ideas and comprehensive understanding of the circular economy development system of agriculture and animal husbandry in Tibet,effectively promotes the promotion and basic change of circular economy of agriculture and animal husbandry,and effectively changes the traditional development model and new innovation model of agriculture and animal husbandry.

Evaluation of the Development of Circular Agriculture in Sichuan Province Based on the Coefficient of Variation

Circular agriculture helps to solve the drawbacks of traditional agricultural production and achieve unified economic and ecological benefits,consistent with the concept of sustainable development.Based on the theoretical perspective of circular agriculture,this paper builds the evaluation indicator system for circular agriculture in Sichuan Province,and uses the coefficient of variation to evaluate the current situation of development of circular agriculture in Sichuan Province from 2000 to 2012.Then it analyzes the obstacles to the development of circular agriculture in Sichuan Province in 2012,and sets forth the targeted recommendations.

Practical Model and Countermeasures for the Development of Ecological Circular Agriculture in Zhejiang Province,China

Development status and five principal practice modes of ecological cycling agriculture are introduced,such as the quantitative reduction mode with the characteristics of fertilizer reduction and clean production,the ecological chain connection and conversion mode including the combination of farming and grazing and the new mode of farming,the agricultural waste recycling mode with biogas as a link and the comprehensive utilization of waste,quality enhancement mode of agricultural products,and eco-cycle mode of agricultural park.Based on the analysis of the socio-economic characteristic environment of these modes,corresponding policy suggestions are put forward in order to promote the development of circular agriculture,such as improving the macro-control mechanism led by the government,promoting the construction of technological innovation system of ecological circular agriculture,and creating the atmosphere for circular agriculture development.

Evaluation on the Development of Circular Agriculture in Guizhou Province Based on Entropy Method

Vigorously developing agricultural circular economy is an effective way to achieve sustainable agricultural development,and a strategic measure to ease the pressure on agricultural resources,protect ecological and clean resources,and promote sustainable agricultural and rural economic development. From the theoretical perspective of circular agriculture,this paper builds the evaluation indicator system for circular agriculture,and uses entropy method to carry out the comprehensive evaluation of the development level of agricultural circular economy in Guizhou Province from 2003 to 2012. At the same time,this paper analyzes the obstacles to the development of agricultural circular economy in Guizhou Province in 2012,and sets forth the relevant recommendations based on these limitations,in order to improve the development level of circular agriculture in Guizhou Province.

Development Situations and Countermeasures of Low Carbon Ecological Circular Agriculture:A Case Study of Nantong City

Developing the low carbon ecological circular agriculture is an effective approach to realizing low carbon development of agriculture. Through investigation on existing measures and performance of development of low carbon type ecological circular agriculture in Nantong City, we analyzed the potential and problems of Nantong City in developing low carbon type ecological circular agriculture. Finally, with reference to domestic and foreign research achievements and practical experience, we put forward countermeasures for developing low carbon type ecological circular agriculture in Nantong City from building technical system and government guidance.

Current Situation and Countermeasures for the Development of Ecological Circular Agriculture in Zhejiang Province

Based on the analysis of present situation of ecological circular agriculture development in Zhejiang Province, the problems of limited resources, backward technology and capital shortage were proposed, and the solutions were put forward to promote the construction of modem agriculture industry system and accelerate the change from the traditional agriculture model to ecological circular agriculture model, such as choosing suitable development models according to local conditions, promoting the construction of agricultural demonstration zones, improving ecological technology, and strengthening the comprehensive utilization of resources and farming system innovation.

Path Exploration and Countermeasure Innovation for Developing Circular Agriculture in Southeast China

This paper firstly elaborated current situation of agricultural resources and ecological environment protection of China,and pointed out that circular agriculture is an inevitable choice for sustainable development of agriculture and effective approach for low-carbon economic development. Then,it analyzed mode and benefit of typical circular agriculture,such as ecological orchard in southeast hills,sightseeing ecological agricultural garden,and crop straw use. Finally,it came up with countermeasures for further developing circular agriculture,including integrating building system and establishing suitable mode,formulating production standard and ensuring food safety,strengthening technological innovation,and supporting sustainable development.

Evaluation of the Development of Circular Agriculture in Chongqing City Based on Entropy Method

The circular agriculture is conducive to achieving the purpose of efficient agricultural economy and environment- friendliness.Based on the perspective of circular agriculture theory,this paper builds the evaluation indicator system for circular agriculture,and uses entropy method and Matlab analysis tool to carry out the comprehensive evaluation of the level of agricultural development in Chongqing City during the period 2003- 2012. It analyzes the obstacles to the development of circular agricultural economy in Chongqing City in 2012,and finally puts forward the corresponding recommendations.

Breaking Key Obstacles on Developing Circular Agriculture and Promoting Agricultural and Pasture Resources Benefit

The present situation,problems and constraints of the circular agriculture development in Hebei Province are systematically analyzed,the subject modes suitable for the development of circular agriculture and the value-added potential are described,and finally some proposals are put forward.

Researches on Relationship between Circular Agriculture and Industrial Diversity

First, this paper establishes the conceptual model of circular agriculture, conducts systematic analysis on the circular agriculture on the basis of conceptual model, and discusses the characteristics of closeness and openness of circular agriculture and relationship between closeness and openness of circular agriculture. Second, this paper introduces the industrial diversity related to circular agriculture, defines the concept of industry and the concept of industries related to agriculture, and illustrates the related industries that are conducive to circular agriculture and the related industries that are not conducive to circular agriculture. Finally, this paper analyzes the mutual relationship between circular agriculture and industrial diversity as follows: in the system of circular agriculture, the industrial diversity can transform the wastes in upstream industries into resources in downstream industries; the industrial diversity creates possibility for recycling of agricultural byproducts; the industrial diversity is conducive to the diversification of industries related to circular agriculture.

Comprehensive Benefit Analysis on Development Models of Circular Agriculture in Wangcang County of Sichuan Province

Taking Wangcang County of Sichuan Province as an example,this paper made comprehensive benefit analysis on models of circular agriculture in Wangcang County. Major models include " pig- biogas- fruit", " pig- biogas- vegetable",and " pig- biogas- tea". It made cost benefit analysis of economic,social and ecological benefits. Through benefit analysis charts,it obtained that the net present value of each household building biogas pool is 6029 yuan. In this way,it significantly improved ecological environment and social benefits,and the agricultural economic development model gradually changes to sustainable development model. However,there are still problems of insufficient government input and single model of agricultural circular economy. Therefore,government should increase input and develop diversified agricultural circular economical models in accordance with local situations,to realize sustainable agricultural development.

Orientation of Government's Role in Building the Technology System of Circular Agriculture

This article expounds the economic characteristics of circular agricultural technology.Since the circular agricultural technology has characteristics and externality of public goods,the government participation is necessary in building the technology system of circular agriculture,in order to avoid "free rider" behavior in the consumption of public goods and internalize externality.We analyze the orientation of government's role in building the technology system of circular agriculture:the government is the leader,designer,organizer and regulator in building the technology system of circular agriculture;the government orientates the four roles precisely in building the technology system of circular agriculture,to ensure that they do not cross the line,but be indispensable all the while.

Farmers' Cognition of Circular Agriculture and its Influencing Factors: A Case Study of Wannian County in Jiangxi Province

Based on the current situation of agricultural development and agricultural material utilization in Wannian County of Jiangxi Province,we mainly use the form of questionnaire survey and design the relevant questions,to study the farmers' awareness of circular agriculture and its influencing factors. The study results show that some factors have a significant impact on farmers' awareness of circular agriculture,such as householders' age,education level,the proportion of agricultural income to household income,having attended agriculture-related lectures,and whether to be concerned about the information related to agriculture. Through the study in this article,we aim to provide better theoretical reference for the development and study of circular agriculture in Wannian County of Jiangxi Province.

Thinking on Circular Agriculture in the Low-carbon Development Situation

The concept of low-carbon economy was introduced firstly, and then patterns and principles of circular agriculture were analyzed, finally noticeable problems during circular agricultural development were put forward, such as increasing the output of circular agriculture and farmers＇ in- come, improving the market system of agricultural products, and making an effort to improve the ability of circular agriculture to adapt to climate change.

Study on the Circular Agriculture Development in Beijing's Mountain Areas

Circular agriculture is an essential way to realize the positive recycling of ecology and harmonious development of the country construction.The sustainable development of Beijing's mountain areas depends on the background and orientation of ecological economy.Beijing's mountain areas bear the responsibility of protecting the ecological safety of the whole Beijing district and also the exploration of circular agriculture in mountain areas is very important to promote the sustainable use of agriculture resources.Beijing's mountain areas have possessed some practical experience in recycling agriculture development.Through summarizing the development mode and analyzing the development practice,the article puts forward three key segments of promoting Beijing circular agriculture development:strengthen propagate,develop superiority and built management mechanism.

Innovation of China's Circular Agricultural Development in the Perspective of Low Carbon Economy

On the basis of the concept and characteristics of circular economy, this paper analyzes the restraining factors of China's circular agricultural development as follows: issues concerning agriculture, countryside and farmers are outstanding; the problems of agricultural resources and agricultural ecological environment are serious; the quality of agricultural products cannot meet the demand of domestic and international market for food. Based on the internal requirements of low carbon economic development, this paper advances four innovative models concerning China's circular agricultural development as follows: the model of combining planting and breeding of agriculture, the developmental model of leisure and sightseeing, ecological integration model, and the developmental model of reusing agricultural byproducts. Every region should choose or create different circular agricultural model in different domains, in order to better use agricultural resources, reduce the consumption of agricultural energy inputs, reduce the emission of agricultural greenhouse gas, develop low carbon agriculture, and make great contribution for meeting the international challenges and promoting China's agricultural development.

Urban Agricultural Development from the Perspective of Circular Economy——An Analysis of Sino-Singapore Eco-city Model in Tianjin

The connotation and development of circular economy and circular agriculture are illustrated from the perspective of circular economy.Take the duplicable Sino-Singapore Eco-City in Tianjin as a case to analyze the background,significance and features of building Sino-Singapore Tianjin Eco-City and point out the sustainable developmental orientation of the "three harmony and three capabilities" as well as its inspiration on the development of Tianjin urban agriculture from the aspects of water-saving,land-saving and energy-saving.Under the direction of circular economy theory,the enhancement of economical utilization of agricultural resources and resource utilization of agricultural wastes has positive effects on improving urban environment:decentralize organic solid wastes from sewage cycle system;further study the physiological and biochemical mechanism of increasing yield and income of ecological agriculture;bring urban agriculture into city land utilization planning and city development planning.

Evaluation on the Development of Agricultural Circular Economy in Hunan Province

By using conceptual model of BPEIR(Behavior-Pressure-Effect-Impact-Response) and Delphi method,we establish the evaluation index system of agricultural circular economy including four indices,namely index of socio-economic development,index of reducing input of resources,index of recycling of resources and index of safety of environment and resources.We conduct comprehensive evaluation on developmental level of agricultural circular economy from 1998 to 2007 in Hunan Province.The analysis results show that the agricultural circular economy of Hunan Province from 1998 to 2007,on the whole,has the tendency of development with annual growth rate of 1.89%.The annual decrease rate of recycling of resources and reducing input of resources from 1999 to 2003 is 25% and 11% respectively,which has become the main factor impeding development of agricultural circular economy.After the year 2003,it is mainly reducing input of resources.