Combating climate change; turn greenhouse gases into energy

Combating climate change; turn greenhouse gases into energy

SADAF SALEEM

Department of Plant Breeding and Genetics, University of Agriculture Faisalabad.

In this century, Climate change is the most discussed and threatening issue to survival on the planet. An elevated CO₂ emission in the atmosphere is the key factor contributing to climate change. Recently a number of research studies are focusing on lowering the CO₂ emission levels in atmosphere as well as plants engineering to cope with this climate change scenario. Photosynthesis is the main biochemical process which is direly affected by CO₂ concentration in the surroundings. Rate of photosynthesis increase as with increase in CO₂ concentration but levels above 340 ppm (as are present) adversely affect the photosynthesis. Excess of CO₂ reduce transpiration rate and plant growth which in turn results in less photosynthesis. So it should be our first priority to clean up the excess CO₂ from the atmosphere before it reaches to toxic levels.

Non-plant Approaches

The most sustainable and environment friendly approach to reduce greenhouse gases is to scavenge CO₂ directly into energy. This will not only meet our increasing energy demands but also efficiently remove this bad stuff from the atmosphere. Following are discussed some novel low cost and efficient CO₂ scavenger approaches.

Artificial photosynthesis

Researchers proposed novel idea of non-plant photosynthesis to lower the CO₂ levels in the atmosphere. Recently a new technology based on this idea was proposed by Fernando Uribe-Romo in University of Central Florida and published the study in 2017 in the Journal of Materials Chemistry A. The idea was based on triggering photosynthesis in a synthetic material made up of metal organic frameworks. This material in the presence of blue LED light breakdown carbon dioxide into harmless formate and formamides as solar fuel. The team is working to achieve similar results with other wavelengths of light too. Successful results may hope to reduce CO₂ levels more efficiently.

Turn CO₂ into ethanol

Converting CO₂ directly into ethanol could be one of the easiest, efficient and cheapest way to combat this greenhouse gas. Actually this conversion was accidently made by scientists working at the Oak Ridge National Laboratory in Tennessee in October 2016. They were working to convert CO₂ into methane but accidently produced ethanol from CO₂ on its own at room temperature. The catalyst used was made up of copper nanoparticles embedded in carbon nano spikes. Ethanol is renewable fuel and this could be a breakthrough to reduce major greenhouse gas at extra benefits of biofuel.

Genetically engineered algae

The process of photosynthesis is very similar in higher plants and algae. Both use water and carbon dioxide in presence of sunlight to synthesize glucose and release oxygen. Algae use bicarbonate as a source of carbon dioxide, taken up by algal cells through bicarbonate transporters. Inside the bicarbonate is converted into CO₂ and fixed by Rubisco to start series of reactions. Microalgae has great potential to capture CO₂ as bicarbonate in ponds, hence reduce CO₂ levels from power stations and other point sources of carbon dioxide emissions which are contributing to global warming. Algae under normal growth conditions use this energy for faster cell divisions and rapidly develop high masses which serve as a major source of biofuel. Recently a group of scientists at the University of California, San Diego share their findings in May 2017. They working on renewable energy sources developed eco-friendly genetically engineered algae. This could serve as better renewable biofuel as well as CO₂ scavenger to lower greenhouse gases from the atmosphere. Furthermore this GMO algae is more productive to produce protein contents as compared to crop plants hence it may serve as good replacement of animal feed and fish meal. Various trials and several biosafety concerns are under consideration before its commercial use in outdoors.

References

1. Matthew Wade Logan, Suliman Ayad, Jeremy D. Adamson, Tristan Dilbeck, Kenneth Hanson, Fernando J. Uribe-Romo. Systematic Variation of the Optical Bandgap in Titanium Based Isoreticular Metal-Organic Frameworks for Photocatalytic Reduction of CO2 under Blue Light. J. Mater. Chem. A, 2017; DOI: 10.1039/C7TA00437K
2. Song, Y., et al. (2016). “High-Selectivity Electrochemical Conversion of CO2 to Ethanol using a Copper Nanoparticle/N-Doped Graphene Electrode.” Chemistry Select 1(19): 6055-6061.
3. Sayre, R. (2010). “Microalgae: The Potential for Carbon Capture.” BioScience 60(9): 722-727.