Global mean surface temperatures have increased by 0.6-1.2^oF since the late 19th century. The 20th century's 10 warmest years all occurred within the last 15 years. Increasing concentrations of greenhouse gases (CO₂, CH₄, SOx, NOx, and ozone) are likely to accelerate the rate of climate change. Among those gases, carbon dioxide is the biggest concern to the scientists.

Our major research programs conducted in this field are to develop an advanced biological technology for effective and efficient recovery of greenhouse gases resulting from the production and use of fossil fuels. Photosynthetic microalgae can play a huge role in carbon sequestration, because they have high photosynthetic rates per unit biomass and can be cultivated in a compact space. The ultimate goal of the project, therefore, is to construct a closed photobioreactor, which will utilize 100% of the CO₂ during algal cultivation.

Algal Cultivation

Various strains of microalgae in cultivation

Algal Cultivation for greenhouse gas recovery

In the clean room, various strains of microalgae have been cultured considering parameters such as pH, dissolved oxygen, ammonia, carbon dioxide, optical density, algal cell density, light intensity, and temperature. The laboratory is equipped with two fume hoods attached with various types of lamps, a UV-Visible spectrophotometer, a centrifugal separator, gas analyzers for sensing CO2, O 2, H2S, and SO2, ion selective electrodes for sensing various emission gases, pH meters, microscopes, and electric ovens.

Photobioreactor

Photo Bioreactor array of 50 light sources

Photobioreactor unit for algal cultivation

In addition, optical studies related to the algal cultivation have extensively been performed. A photobioreactor unit composed of 50 individual light sources and bioreactors has been set up in this laboratory. The system was very effectively utilized in previously sponsored projects, and will be modified for future programs. There have been a couple of photobioreactors constructed and applied to the algal cultivation. At the present time, a 10-L photobioreactor is being constructed.

Gas Scrubbing System

Gas Scrubbing in the wet processing room

In the wet processing room, a gas-scrubbing system has been investigated. Possible greenhouse gases such as CO 2, SO 2, etc. have been successfully separated and utilized for nutrients to support algal growth. An efficiency of almost 99% for greenhouse gas recovery has been achieved.

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Dr. J. Hwang is the Principle Investigator of the DOE supported CO₂ Bioscrubber Project. Dr. M. Jeong is assisting Dr. J. Hwang in managing the daily activities in the project. She is an analytical chemist with a biology background and supervises the work of undergraduate and graduate students (Biology and Chemical Engineering majors at Michigan Technological University).

Voice:(906) 487-2600	Michigan Technological University
Fax:(906) 487-2921	Institute of Materials Processing
E-mail: jhwang@mtu.edu	Houghton, Mi. 49931