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Biomedical subjects

R C Axtmann

Publications and source records attributed to R C Axtmann.

5 recordsLinked to original sources
PubMed1975

Emission control of gas effluents from geothermal power plants.

Geothermal steam at the world's five largest power plants contains from 0.15 to 30% noncondensable gases including CO(2), H(2)S, H(2), CH(4), N(2), H(3)BO(3), and NH(3). At four of the plants the gases are first separated from the steam and then discharged to the environment; at the fifth, the noncondensables exhaust directly to the atmosphere along with spent steam. Some CO(2) and sulfur emission rates rival those from fossil-fueled plants on a per megawatt-day basis. The ammonia and boron effluents can interfere with animal and plant life. The effects of sulfur (which emerges as H(2)S but may oxidize to SO(2)) on either ambient air quality or longterm human health are largely unknown. Most geothermal turbines are equipped with direct contact condensers which complicate emission control because they provide two or more pathways for the effluents to reach the environment. Use of direct contact condensers could permit efficient emission control if coupled to processes that produce saleable quantities of purified carbon dioxide and elemental sulfur.

Air Pollution↗
PubMed1975

Heavy metal contamination from geothermal sources.

Liquid-dominated hydrothermal reservoirs, which contain saline fluids at high temperatures and pressures, have a significant potential for contamination of the environment by heavy metals. The design of the power conversion cycle in a liquid-dominated geothermal plant is a key factor in determining the impact of the installation. Reinjection of the fluid into the reservoir minimizes heavy metal effluents but is routinely practiced at few installations. Binary power cycles with reinjection would provide even cleaner systems but are not yet ready for commercial application. Vapor-dominated systems, which contain superheated steam, have less potential for contamination but are relatively uncommon. Field data on heavy metal effluents from geothermal plants are sparse and confounded by contributions from "natural" sources such as geysers and hot springs which often exist nearby. Insofar as geothermal power supplies are destined to multiply, much work is required on their environmental effects including those caused by heavy metals.

Air↗