Present value | EPFL Graph Search

In economics and finance, present value (PV), also known as present discounted value, is the value of an expected income stream determined as of the date of valuation. The present value is usually less than the future value because money has interest-earning potential, a characteristic referred to as the time value of money, except during times of zero- or negative interest rates, when the present value will be equal or more than the future value. Time value can be described with the simplified phrase, "A dollar today is worth more than a dollar tomorrow". Here, 'worth more' means that its value is greater than tomorrow. A dollar today is worth more than a dollar tomorrow because the dollar can be invested and earn a day's worth of interest, making the total accumulate to a value more than a dollar by tomorrow. Interest can be compared to rent. Just as rent is paid to a landlord by a tenant without the ownership of the asset being transferred

Tunneling Splittings in Water Clusters from Path Integral Molecular Dynamics

Christophe Louis Joseph Jean-Luc Vaillant

We present calculations of tunneling splittings in selected small water clusters, based on a recently developed path integral molecular dynamics (PIMD) method. The ground-rotational-state tunneling motions associated with the largest splittings in the water dimer, trimer, and hexamer are considered, and we show that the PIMD predictions are in very good agreement with benchmark quantum and experimental results. As the tunneling spectra are highly sensitive to both the details of the quantum dynamics and the potential energy surface, our calculations are a validation of the MB-Pol surface as well as the accuracy of PIMD. The favorable scaling of PIMD with system size paves the way for calculations of tunneling splittings in large, nonrigid molecular systems with motions that cannot be treated accurately by other methods, such as the semiclassical instanton.

2019

Methodology for the optimal design of an integrated first and second generation ethanol production plant combined with power cogeneration

Rami Bechara, François Maréchal, Jean-Marc Schweitzer

The application of methodologies for the optimal design of integrated processes has seen increased interest in literature. This article builds on previous works and applies a systematic methodology to an integrated first and second generation ethanol production plant with power cogeneration. The methodology breaks into process simulation, heat integration, thermo-economic evaluation, exergy efficiency vs. capital costs, multi-variable, evolutionary optimization, and process selection via profitability maximization. Optimization generated Pareto solutions with exergy efficiency ranging between 39.2% and 44.4% and capital costs from 210 M

to 390 M

. The Net Present Value was positive for only two scenarios and for low efficiency, low hydrolysis points. The minimum cellulosic ethanol selling price was sought to obtain a maximum NPV of zero for high efficiency, high hydrolysis alternatives. The obtained optimal configuration presented maximum exergy efficiency, hydrolyzed bagasse fraction, capital costs and ethanol production rate, and minimum cooling water consumption and power production rate.

2016

Methodology for the optimal design of an integrated sugarcane distillery and cogeneration process for ethanol and power production

Rami Bechara, François Maréchal, Jean-Marc Schweitzer

The application of systematic methodologies for the optimal design of integrated processes has seen increased interest in literature, namely for bioprocesses. The development and application of such a methodology to ethanol and power production from sugarcane and leaves, in a combined distillery and cogeneration plant is investigated in this article. The methodology breaks down as follows: process simulation, heat integration and thermo-economic evaluation, bi-objective multi-variable evolutionary optimization, and process selection. The objective functions are exergy efficiency and capital cost, whereas the selection criterion is the maximization of the Net Present Value (NPV). This choice was motivated by the variation in process related market parameters and their impact on profitability. Optimization generated 31 optimal trade-off solutions with better results than literature. Exergy efficiency ranged between 37.6% and 41.7% and capital costs between 155 M

and 210 M

. Process selection led to a single configuration maximizing NPV for four economic scenarios. The configuration's exergy efficiency and capital costs were equal to 40.63% and 163 M$. This point presented an optimal compromise between heat integration and capital costs. This article provides a breakthrough in the application of this methodology, to the investigated process specifically. (C) 2016 Elsevier Ltd. All rights reserved.

Pergamon-Elsevier Science Ltd2016

Methodology for the optimal design of an integrated sugarcane distillery and cogeneration process for ethanol and power production

Rami Bechara, François Maréchal, Jean-Marc Schweitzer

and 210 M

Pergamon-Elsevier Science Ltd2016

Methodology for the optimal design of an integrated first and second generation ethanol production plant combined with power cogeneration

Rami Bechara, François Maréchal, Jean-Marc Schweitzer

to 390 M

2016