Methanol Econ­omy

A high per­cent­age of fu­els pro­duced are used for trans­porta­tion and most of these like petrol and diesel are from oil & gas. Since long, par­tic­u­larly af­ter sud­den oil price hikes, the world has been search­ing for suit­able al­ter­na­tives. Since 1990s, methan

Chemical Industry Digest - - Chemingineering -

Though In­dia’s methanol econ­omy is yet to take off from the draw­ing boards, it has be­gun to make waves in pop­u­lar me­dia in last few months. Methanol Econ­omy is hardly a new con­cept, hav­ing been ad­vo­cated as far back as 1990s by the Chem­istry No­bel Lau­re­ate George Olah. But how we and prob­a­bly China per­ceive this new paradigm is dif­fer­ent from the way rest of the world does.

Trans­port Fuel

The at­trac­tive­ness of methanol as a clean and ef­fi­cient sub­sti­tute for petrol is quite well known. Pure methanol has been used as the fuel in the pop­u­lar Indy Car Races in USA since 1965, pri­mar­ily from safety con­sid­er­a­tions. From 1980 to 2005, USA ran a suc­cess­ful methanol cam­paign, in which tens of thou­sands of ve­hi­cles were con­verted to op­er­ate on M85, con­sist­ing of 85% methanol. But in 2005 USA aban­doned methanol in favour of crop-based ethanol, in what was clearly a po­lit­i­cal de­ci­sion. That leaves China as the big- gest user of methanol for trans­porta­tion. Con­tribut­ing 55% to the global pro­duc­tion, China pro­duces 47 mil­lion tonnes of methanol an­nu­ally. Methanol is blended with petrol in var­i­ous pro­por­tions rang­ing from 5% to 100%, 15% be­ing the most com­mon. Geely, a Chi­nese com­pany, has emerged as the world’s lead­ing methanol ve­hi­cle man­u­fac­turer, with a ca­pac­ity to pro­duce 200,000 ve­hi­cles per an­num. China has a cur­rent stran­gle­hold on the methanol econ­omy, dom­i­nat­ing both pro­duc­tion and con­sump­tion.

Fuel Cells

But blend­ing with petrol is at best a pit­stop on the long and ar­du­ous jour­ney of methanol. Many coun­tries, In­dia, France, Bri­tain and Nor­way among them, have de­clared their plans to junk in­ter­nal com­bus­tion en­gine in favour of elec­tric ve­hi­cles. In­dia has set an am­bi­tious tar­get of 2030 for go­ing fully elec­tric. How does this stack up with the adop­tion of methanol econ­omy? The an­swer is fuel cell.

Elec­tric-pow­ered ve­hi­cles have two op­tions to source their power: Bat­tery or Fuel Cell. For long, opin­ion has been di­vided equally among ex­perts on which is a bet­ter op­tion. But in a sur­vey by KPMG early this year, Fuel Cells found an over­whelm­ing back­ing from au­to­mo­bile com­pa­nies, be­cause they don’t need a charg­ing in­fra­struc­ture. And among Fuel Cells, it is the Di­rect Methanol Fuel Cell (DMFC) that has the power to pro­pel the methanol econ­omy for­ward. In­vented in 1990s by a host of in­sti­tu­tions, in­clud­ing NASA, the DMFC uses an acidic solid poly­mer, in the form of a mem­brane, as the elec­trolyte. Methanol and wa­ter re­act elec­tro­chem­i­cally to gen­er­ate power. The DMFC is ideal for trans­port ap­pli­ca­tion com­pared to the bulky hy­dro­gen based fuel cells be­cause of its high en­ergy den­sity and quick re­fu­el­ing. Daim­ler-Chrysler un­veiled the first DMFC pow­ered ve­hi­cle in 2000. In 2015, Den­mark opened the first methanol re­fill­ing sta­tion to ser­vice DMFC fit­ted ve­hi­cles. How­ever, the ef­fi­ciency of DMFC is cur­rently poor and im­prove­ments are re­quired on the cat­a­lysts

that make up the elec­trodes.

Dimethyl Ether

Another po­ten­tial ap­pli­ca­tion of methanol ex­cit­ing the In­dian think­tank is us­ing it for pro­duc­tion of dimethyl ether (DME). DME has prop­er­ties that are re­mark­ably sim­i­lar to LPG. China, the world’s largest pro­ducer of DME, used it widely to blend with LPG. But this prac­tice was banned in 2008, fol­low­ing safety con­cerns. The blended fuel was found to dam­age the rub­ber sealants of the LPG cylin­ders. De­spite the ban, the blend­ing of LPG with DME con­tin­ues to be ram­pant. DME has also been used as a sub­sti­tute for diesel with lim­ited suc­cess; the is­sues be­ing poor en­gine lu­bri­ca­tion.

Methanol

At the heart of the Methanol Econ­omy is its pro­duc­tion. It is im­por­tant to re­mem­ber that methanol is not the source of en­ergy, but only its car­rier. En­ergy de­rived from other sources, pri­mar­ily coal, nat­u­ral gas and biomass, is con­verted and stored in methanol. The ef­fi­ciency of this en­ergy con­ver­sion process is cen­tral to the suc­cess of methanol econ­omy. China pro­duces 85% of it methanol from coal and the re­main­ing from nat­u­ral gas. In­dia also wants to put coal at the cen­tre of its methanol econ­omy. Syn­gas for methanol syn­the­sis is ob­tained from nat­u­ral gas by steam re­form­ing. Coal and biomass have to be gasi­fied first and then cleaned up be­fore syn­gas can be pro­duced. China has ex­per­i­mented with dif­fer­ent types of gasi­fiers and has a very ma­ture coal gasi­fi­ca­tion tech­nol­ogy. In­dia on the other hand has strug­gled to es­tab­lish the gasi­fi­ca­tion tech­nol­ogy for its high-ash coal. Both coal and nat­u­ral gas would only be tran­si­tion fu­els be­fore we move on to biomass in or­der to meet the re­new­able en­ergy goals of Paris agree­ment.

Biomethanol

It is the re­new­able feed­stocks that per­haps pose the big­gest threat to the methanol econ­omy. The con­ver­sion ef­fi­ciency of biomass to methanol is presently in the range of 50-60%. Biomass gasi­fiers are avail­able in var­i­ous de­signs like fixed bed, flu­idised bed, en­trained bed etc. These have been suc­cess­fully demon­strated for lo­cally avail­able biomass. Scale-up, cost re­duc­tion and abil­ity to han­dle di­verse feed­stocks are key chal­lenges. Another po­ten­tial threat comes from the still-ma­tur­ing tech­nol­ogy for pro­duc­ing ethanol from cel­lu­losic biomass. Ethanol con­tin­ues to be lob­bied hard in USA. Wa­ter con­sump­tion is sig­nif­i­cantly lower for methanol pro­duc­tion than ethanol, even af­ter ac­count­ing for the methanol’s lower en­ergy den­sity.

Meth­ane Hy­drates

No over­view of methanol econ­omy can be com­plete with­out ref­er­ence to meth­ane hy­drates, de­posits of which are be­lieved to be a larger source of en­ergy than that com­bined from oil, gas and coal. The cur­rent es­ti­mate of meth­ane trapped in gas hydrate de­posits is in the or­der of 105 tril­lion cu­bic me­ters, 99% be­ing in ocean sed­i­ments. While com­mer­cial pro­duc­tion of meth­ane from gas hy­drates is at least a decade away, a ma­ture Methanol Econ­omy can im­mensely profit from it. Much re­search is un­der­way for the bi­o­log­i­cal ox­i­da­tion of meth­ane to methanol us­ing methan­otrophic bac­te­ria.

Holy Grail

The Holy Grail of Methanol Econ­omy would be to cap­ture car­bon diox­ide from the at­mos­phere and con­vert it to methanol. Such a process is in­deed fea­si­ble and has been patented by George Olah and his team. Hy­dro­gen re­quired to re­act with car­bon diox­ide can be gen­er­ated elec­trolyt­i­cally from wa­ter us­ing re­new­able so­lar en­ergy, for ex­am­ple. This will make Methanol Econ­omy car­bon-neu­tral and truly cir­cu­lar.

Post Script - This col­umn is ded­i­cated to the mem­ory of George Olah, the cham­pion of Methanol Econ­omy, who passed away in March this year.

Read­ers’ re­sponses may be sent to k.sa­has­rana­man@gmail.com or che­mindi­gest@gmail.com

K Sa­has­rana­man In­de­pen­dent Con­sul­tant - Process Engi­neer­ing, En­ergy, Util­i­ties and Safety

Newspapers in English

Newspapers from India

© PressReader. All rights reserved.