3/2017
Ambient air interaction with lead roofing
Lead roofing represent environmental risk due to runoff loads absorbing in soil and surface water. Longterm field study lasting 112 d included monitoring of ambient air quality, pluviometric and meteorological variables, and determination of lead in aggregated week samples of wet deposition in almost natural and polluted sites. Mean lead mass concentration in runoff water of rural site was 6,8±1,6 μg/L and 14±3,2 μg/L for urban site. Those results are significantly below the limit value (50 μg/L) for irrigation water. Lead roofing probable cannot influence the surface water.
Marine Fuels after 2020
Life Cycle Assessment of CO2 capture technology of high temperature carbonate loop
Paper is focused on the current results of the study of life cycle assessment (LCA) of carbonate loop. Carbonate loop is technological system which aim is to capture CO2 from flue gases generated by the heat power plants. This paper introduces results made from life cycle assessment of carbonate loop with reference to 250MWe power unit. The assessment was made by two LCA methods – CML and ReCiPe in GaBi software. Two main were considered for the assessment: 1. 250MWe power unit without capture unit, 2. 250MWe power unit with capture unit. Scenario 2 is then divided into further three different scenarios : 2.1 Power unit in connection with carbonate loop where calcium carbonate is heated by the energy from the lignite consumption of power unit, 2.2 Power unit in connection with carbonate loop, where calcium carbonate is heated by external source of heat from natural gas, 2.3 Power unit in connection with carbonate loop, where calcium carbonate is heated by external source of heat from natural gas, and heat from carbonation process is used in a form of steam. Both LCA meth-ods are confirming the most negative scenario 2.1 if the carbonate loop is considered. The most positive scenario is 2.3 where steam can be used for further heating in the system. Also further substitution of lignite by natural gas as a source of carbonate loop heating contribute to the better environmental characterization of the whole pro-cess.
Catalytic Methanization of Biogas using Nickel Catalyst
Catalytic methanation of Biogas represents an alternative route to the currently used methods of Biogas upgrading to Biomethane. One of the most significant benefit of such approach is the incomparable increase in the overall yield of Biomethane produced from Biogas. The paper describes the basics of catalytic methanation of carbon dioxide and hydrogen to form methane and water. The main topic is the comparison of catalytic methanation of two model gas mixtures using a nickel based catalyst. The firs gas mixture which comprises of stoichiometric (1:4) ratio of carbon dioxide and hydrogen served as a reference gas. The second gas mixture with its composition simulated Biogas with the addition of hydrogen to obtain the stoichiometric ratio of carbon dioxide and hydrogen. Both gas mixtures were tested in laboratory apparatus using fixed bed reactor under pressure up to 6 MPa and temperatures up to 320 °C. It was proved that methanation using nickel based catalyst produces gas with methane mole fraction of more than 0,9 in temperature range from 200 to 220 °C. The highest methane yield was achieved using the Biogas/hydrogen mixture under the pressure of 6 MPa where the molar fraction of methane in the produced gas reached 0,98.