精馏过程的节能和优化设计的探讨

精馏过程的节能,对于减少能源消耗,降低生产成本和保护环境具有十分重要的意义.在精馏过程中可以采用最适宜回流比操作和最佳进料状态,使用中间冷凝器和中间再沸器,高效精馏、热泵精馏.合理安排多组分物料分离流程,直接利用过程热量及开发应用高效换热器等措施.本文从最佳回流比R的选择、进料温度及进料状态的确定等方面,详细的分析了在精馏塔的设计过程中,如何实现设计的优化问题,以实现节能降耗.     

Optimal investment with fixed financing costs

Models with a premium on external finance produce counterfactual predictions about liquidity management. We address this shortcoming by introducing a fixed cost of increasing external finance into an otherwise standard investment/financing problem. This additional financial friction is well-motivated by case studies and our analysis shows that it generates more realistic predictions about liquidity management: firms hold external finance and idle cash simultaneously, and may invest an additional dollar of cash flow in liquidity rather than repaying external funds or investing in productive capital. In addition to better fitting the stylized facts about the time-series and cross-sectional pattern of liquidity holding, these results may help shed light on the fragility of estimates of investment–cash flow sensitivities.     

Public finance and the optimal speed of transition*

We develop a general equilibrium model that jointly considers the influence of capital accumulation constraints and of labour market frictions on the process of transition. We endogenize the economic and budgetary costs of different government policies and show that, early in transition, governments ought to subsidize state firms. Provided that intertemporal commitment is feasible, this policy limits the initial output fall, which relaxes capital accumulation constraints, accelerates transition, and increases welfare. Moreover, by resorting to indirect – instead of direct – taxes, governments can bring the path of transition closer to the first best. Yet, political pressures may induce a policy of suboptimal subsidization.     

Analysing Materials and Energy Flows in an Industrial District using an Enterprise Input–Output Model

Recent approaches to sustainable development leave much room for policies at a local level. In fact, it is becoming evident that targets such as increasing resource productivity, preserving natural cycles, or extending the present level of welfare, are best pursued within the confines of a local area. In particular, environmental changes are best brought about by considering local systems of firms as cornerstones of cooperative strategies and using data on materials and energy use in physical terms. In this paper, an enterprise input–output model is developed for an industrial district, i.e. a local group of firms specialized in the production of a single final output. The model allows for a detailed quantitative analysis of materials and energy flows and the consequent generation of waste and pollution. As a planning tool, the model may be used to evaluate alternative scenarios, such as the possibility of re- using waste taking account of sustainability requirements. An empirical case study applies the model to an industrial district in Southern Italy producing leather sofas.     

Environmental protection versus economic growth

This paper presents and analyses the differences in the eco-models implemented worldwide （such as whether and how carbon taxes being ＂recycled＂）, or in their efficiency parameters （inconsistent parameter values that account for different results）. This is the assumption that a real tradeoff exists between the production of environmental goods. The present article empirically proves that something must be given up in order to gain something else, and once equations are specified to trace out the path of the economy over time, the natural economic formulation of such equations will embody the notion of economic and bio-tradeoffs.     

农业供应链金融视角的农户信贷约束缓解效应研究——来自湖南农户的经验证据

采用多元多值非条件Logistic回归方法,依据湖南省50个县(市、区)1059个农户样本数据,考察农业供应链金融对农户信贷约束的缓解效应。结果显示：农户参与农业供应链金融能够缓解供给型与需求型农户信贷约束,缓解效应随着农户收入增长、金融发展和农户社会资本提升而减弱,机制检验证实了信息对称、信用等级、交易成本、抵押替代在缓解农户信贷约束过程中起到部分中介效应。鉴于此,需要在创新模式、优化环境以及加强引导上着力发展农业供应链金融。     

结构异质性对中国能源高质量发展的影响研究

基于结构异质性对能源高质量发展影响的理论分析,使用稀疏主成分分析方法测度中国能源高质量发展水平,构建中国和八大经济区域面板分位数回归模型,实证研究了结构异质性对中国能源高质量发展的影响。结果表明：2003—2020年中国能源高质量发展水平有所提升,但仍存在明显的区域发展不平衡问题,西部地区和北部沿海地区的能源高质量发展水平更高。产业结构与能源高质量发展水平呈负相关关系,能源消费结构、资本配置结构与能源高质量发展水平呈正相关关系。     

能源新论——兼论树立科学的能源观

能源在人类社会中是一个历史范畴,不同文明时期的主导能源之间有着深刻的历史联系。工业社会的主导能源本质上是化学能源,这决定了它的局限性。面对工业能源危机,人类必须开拓出比化学能源更深层次的新能源,这就是物理能源。物理能源的开发利用及其向主导能源的转化,是今日经济社会发展的必然趋势。     

外资进入对本土企业风险承担的影响：资本逐利还是风险规避

外资自由化作为我国资本市场开放的重要内容,在促进境内外资本要素互联互通的同时,也深刻影响着微观企业行为。以我国2007—2017年A股上市公司作为研究样本,实证检验外资进入对我国本土企业风险承担的影响。研究发现：外资进入能够显著提升企业的风险承担水平。进一步地,外资进入对企业风险承担的促进效应在融资约束严重、股权集中度更高和市场化进程缓慢地区的企业中更加显著。此外,在不同资本市场开放水平,外资进入对企业风险承担的作用存在明显差异。     

Carbon Taxes and Joint Implementation. An Applied General Equilibrium Analysis for Germany and India

Germany has committed itself toreducing its carbon emissions by 25 percent in2005 as compared to 1990 emission levels. Toachieve this goal, the government has recentlylaunched an environmental tax reform whichentails a continuous increase in energy taxesin conjunction with a revenue-neutral cut innon-wage labor costs. This policy is supposedto yield a double dividend, reducing both, theproblem of global warming and high unemploymentrates. In addition to domestic actions,international treaties on climate protectionallow for the supplementary use of flexibleinstruments to exploit cheaper emissionreduction possibilities elsewhere. One concreteoption for Germany would be to enter jointimplementation (JI) with developing countriessuch as India where Germany pays emissionreduction abroad rather than meeting itsreduction target solely by domestic action. Inthis paper, we investigate whether anenvironmental tax reform cum JI providesemployment and overall efficiency gains ascompared to an environmental tax reformstand-alone. We address this question in theframework of a large-scale general equilibriummodel for Germany and India where Germany mayundertake JI with the Indian electricitysector. Our main finding is that JI offsetslargely the adverse effects of carbon emissionconstraints on the German economy. JIsignificantly lowers the level of carbon taxesand thus reduces the total costs of abatementas well as negative effects on labor demand. Inaddition, JI triggers direct investment demandfor energy efficient power plants produced inGermany. This provides positive employmenteffects and additional income for Germany. ForIndia, joint implementation equips itselectricity industry with scarce capital goodsleading to a more efficient power productionwith lower electricity prices for the economyand substantial welfare gains.