Last month, L&T and NTPC announced a partnership to put up a demonstration plant to convert carbon dioxide into methanol. This small step, L&T hopes, will mean a giant leap into the green fuels of the future.
Subramanian Sarma, Wholetime Director, L&T, who heads the company’s hydrocarbon engineering business, points out that there were three aspects to the conversion of carbon dioxide to liquid fuels like methanol. First, the capture of the gas, which is not a big deal, as technologies are well in hand. The second, generating hydrogen through climate-friendly ways, which basically means electrolysis of water using solar power.
Here again, the technology is not unknown, except that it needs to be improved to enhance efficiency. And finally, catalytic reduction of CO2 to methanol.
“We are evaluating technologies for each of the three segments to adopt them into the demonstration plant,” Sarma told BusinessLine in a recent chat. He said the company could consider involving technology partners.
CO2-to-liquids (or ‘emission-to-liquids’) is an emerging area globally and there is a huge market out there for one who perfects the technology. Quoting from published material, Sarma said that typically a 500 MW coal-fired power plant will annually yield methanol worth ₹6,000 crore to ₹8,000 crore, at the current market prices.
“There is a big market for methanol,” Sarma said, noting that the methanol produced through green pathways, such as that being attempted by the L&T-NTPC venture, would command a premium in the market.
Methanol can be blended with petrol and used in vehicles, but the chemical is also feedstock for a variety of products – solvents, resins, silicone, dietary supplements, acrylic sheets and a range of fuels such as dimethyl ether (DME) and oxymethyl ether (OME). It can also be used as fuel to run ships.
Sarma stressed that it was still early days and cautioned against over-optimism. “Much depends on the success of the demonstration plant,” he said. Typically, he noted, emerging technologies work well in labs and pilot plants but pose challenges while scaling up to commercial levels.
L&T signed a memorandum of understanding with NTPC because both companies had been working independently on clean technologies and hence thought “why not work together”. Sarma said that partnership was open, non-exclusive, but the understanding was that all the work relating to CO2 to fuels would be done under the collaboration. He said the demonstration plant could come up in one-and-a-half years.
Asked L&T was spurred into this area by a view that the hydrocarbons business is on a decline globally, Sarma pointed out that even global oil majors were diversifying into renewable energy and “it would be stupid not to take cognizance of what is happening elsewhere in the world.”
Very few plants
There is but only one commercial scale plant in the world that produces methanol from carbon dioxide—the George Olah plant in Iceland, owned by a company called Carbon Recycling International (CRI).
CRI literature notes that there are two pathways of converting the gas into methanol. One, is to reduce CO2 to Carbon monoxide (CO) and then reduce CO with Hydrogen to make methanol. The second is direct hydrogenation of CO2 with Hydrogen over a metal oxide catalyst. The Iceland plant follows the second method.
“Perhaps the most consequential lesson learned from this (Iceland) enterprise is that producing methanol from CO2 need not be as expensive as most experts had estimated,” says CRI in its website, noting that the production of green methanol would only cost twice as much as natural gas derived methanol.
While even a pilot plant for CO2 conversion into fuels is yet to come, notable progress has been made in the labs.
For instance, Prof Vivek Polshettiwar of the Tata Institute of Fundamental Research has developed a number of catalysts for the process such as nano gold, nano solid acids and nano silica, which have the potential to replace metallic catalysts, which are less stable.
Indian Oil Corporation has been working on a two-stage process through the bio-route (or using bacteria), converting CO2 to acetates and then converting the acetates into useful products like Omega-3.