practical test 20200616 vs1

Page 1

SOLAR AND BIOMASS POWER PRODUCTION AY 2019-20 16th June 2020 Prof. Giampaolo Manzolini Time: 2 hours Instructions for the examination: 1) Clearly indicate your name on all the sheets you will deliver. 2) The score refers to exercises done in a comprehensive manner with exact numerical results. Numerical results correct but not accompa- nied by explanations will not be taken into account. The final score can be normalized according to the average results. 3) Answer briefly and clearly only to the asked questions. Calculations and explanations which do not respond to the questions will not be considered for evaluation even if correct. 4) Talking with colleagues and / or cheating will cause the cancellation of the exam. 5) All the needed data for the resolution of exercises lies on this paper. It is NOT ALLOWED to use material other than this (e.g. books, clipboard etc.). 6) Not all the provided inputs are necessary for the problem solving Exercise 1 (16 points) Consider a biogas plant consisting of a digester with the characteristics of the feedstock reported below. Question a) determine the size of the digester considering a minimum HRT of 23 days and a maximum OLR of 3.5 kgCOD/m3/day the design constraint reported (5 points) Assuming that the actual Biogas Methane Production efficiency (η BMP) is function of the Hydraulic Retention Time (HRT) according to the following equation: 𝜂𝜂= 1 − 1 0.33∙𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑; Question b) calculate the electricity production on yearly base and the resulting LCOE knowing that the supply of the feed is constant throughout the year and the economic assumptions are reported in the table below (4 points) Feedstock cost 5 €/t Power Block cost 1200 €/kWel Digester cost 600 €/m3 Indirect and contingency cost 50% of total installed cost Operation and…