September 2011 (PDF format 670 KB) - Indian Stainless Steel ...

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SIGNIFICANT POTENTIAL FOR STAINLESS STEEL IN BIO ENERGYBiogas typically refers to a gas producedby the biological breakdown of organicmatter in the absence of oxygen. Organicwaste such as dead plant (straws ofcrops like wheat, rice, jowar, bajra, huskof rice etc.), animal material, animaldung, kitchen and human waste etc., canbe converted into a gaseous fuel calledbiogas.The gases-methane, hydrogen andcarbon monoxide (CO) can becombusted or oxidized with oxygen. Thisenergy release allows biogas to be usedas a fuel. Raw biomass can be used asa fuel in any country for any heatingpurpose, such as cooking.Nearly 700 million Indians still burnbiomass as the primary source of energyfor cooking in inefficient cookstoves whichburn wood and other agricultural matterand add to air pollution. In addition, it isa source of health problem in kitchenswith insufficient ventilation.India is the world’s fifth-largest andsecond-fastest-growing producer ofgreenhouse gas emissions. Generatingelectrical power by burning biogas (amixture of methane and carbon dioxideproduced by the bacterial degradation oforganic matter) harnesses thesegreenhouse gases and reduces demandfor fossil fuel-fired generating plants.The Government is exploring thedevelopment of community-drivenbiomass based resources programs tomeet the basic energy needs of thepopulation in areas where electrificationis not possible, such as remote villages.As a climate change co-benefit, a largescale conversion to biomass-energy candecrease India’s greenhouse gasemissions.BIOGAS ENERGY POTENTIALThe Government of India’s Ministry ofNew and Renewable Energy Sources ispreparing a national bio-energy missionto boost power generation from biomass,a renewable energy source abundantlyavailable in India. Surplus biomass inIndia is estimated to be 150 milliontonnes. This could potentially be usedto generate 16 giga watts(16000 MW) ofpower.During the 12th Five-Year Plan (2012-2017), the Indian Government isenvisaging to facilitate large-scale capitalinvestments in biomass-fired powerstations. It will provide power for day-todayrequirements of the population,encourage development of ruralenterprises and provide employment toa large number of people in thecountryside. This could also help in thestabilization of electricity grid.Nearly 70% of the country’s populationlives in villages with marginal access toelectricity. Currently, India has a totalinstalled capacity of 3,000 MW ofbiomass-based power generation. Theministry of new and renewable energy istargeting to double this capacity duringthe 12th Plan (2012-17).According to some estimates, biomassfrom agro and agro-industrial residuecould potentially generate 25,000 MW ofpower in India. This can be further raisedwith wasteland-based integrated energyplantation and power generationsystems.Each MW generated from biomassplants would be able to cover about 6,000rural households. The ministry hasearmarked 3,400 crore for the variousincentive schemes under the biomassmission.POWER GENERATION EQUIPMENTWe present a case study (from ‘NickelMagazine’, volume 23, number 3, June2008) where M/s Capstone TurbineCorporation of Chatsworth, California,U.S.A. installed their first micro turbineto produce biogas energy in Purulia,West Bengal in 2006. Based on thisexperience, they installed few moremicro-turbines at different locations inIndia for generating more biogas energy.The Purulia installation is at a dairy farmand consists of two 30-kilowatt microturbinesystems, one of which is forbackup. These can run either linked orindependently of the power grid. “Whenthe grid is down, it is connected to thedairy to keep it running”.The micro-turbines use nickel alloys andstainless steel in components such asthe combustion chamber, spinningturbine, main rotor shaft, recuperatorhousing etc., all of which runcontinuously with minimal maintenance.Austenitic stainless steels are the mostcost-effective material for the systemsthat clean and compress the corrosivebiogas prior to combustion in microturbines.Biogas is mostly methane with hydrogensulphide present as a contaminant. Whenhydrogen sulphide is mixed with water(with which biogas is always 100%saturated), it becomes a weak acid(hydrosulphuric acid). Carbon dioxideforms a mild carbonic acid in thepresence of water. “Biogas is verycorrosive, which is why we use a lot ofstainless steel”.“Stainless steel has good corrosionresistance to those acids. Predominantlywe use S30400 and S30403, thoughsometimes customers request S31600and S31603, as these are more resistantto corrosion. The S30403 might last 40-50 years whereas the S31603 can last100 years.”A typical compression and cleaningsystem takes the gas drawn off the topof the sludge in a digester, where manurehas decayed for 20-30 days, andcompresses and cleans it before it isburned. In a simplified description of thisprocess, the gas first passes throughfilters that remove the hydrogen sulphide.These tanks will typically be constructedof stainless steel plate 4.8 or 6.4mmthick and are made to withstand negativepressure. The gas then passes througha compression system, where it is raisedto pressures as high as 8.4 kilogramsper square cm (kg/cm2). The piping usedin this process is typically stainlesssteel. Next it passes through heatexchangers to reduce the temperatureto about 4 °C, forcing more water out ofthe gas. The gas is then re-heated to27 °C, reducing the relative humidity to25%. Subsequently, the gas passes intostainless steel vessels where siloxane,a chemical used in lubricants andpersonal care products, is filtered out.Since siloxane turns into a glass-likesubstance at high temperatures it mustbe removed before the gas is burned.After this step, the biogas is delivered toan end-use device, such as a turbine,internal cubustion engine, or fuel cell.CONCLUSION:Given the big plans the Government hasfor use of bio-gas for energy productionin India, austenitic stainless steels havea significant market potential in thissector because they have proved to bethe most cost-effective material for thesystems that clean and compress thecorrosive biogas prior to combustion.STAINLESS INDIA / VOL. 16, NO.3 PAGE 6
STAINLESS STEEL IS IDEAL FOR MITIGATING AIR POLLUTION IN COMMERCIAL VEHICLESCommercial vehicles constitute 1.1% of total vehicular population in Delhi, but account for 90% of total vehicular pollution.THE GOVERNMENT MUST TAKE STRINGENT MEASURES TO CONTROL POLLUTION BY DIESEL COMMERCIAL VEHICLESFossil fuel-based vehicles using petroland diesel emit various air pollutants likeCO (carbon monoxide), HC (unburnedhydrocarbons), NOx (nitrogen oxides),SOx (Sulphates) and PM (particulatematter). These pollutants in auto exhaustare responsible for major diseases andare extremely harmful for humans. InDelhi, for instance, one out of every thirdchild is currently suffering from Asthmaand related respiratory diseases.A study conducted by IIT Delhi in 2007established that even though CNGoperated buses are present in Delhi sincethe year 2000, pollution due to dieselcommercial vehicles is a major sourceof air pollution in the city. Althoughcommercial vehicles constitute only1.1% of the total vehicular population inDelhi, they account for 90% of the totalvehicular pollution in the city. People ofDelhi will distinctly remember the daywhen all diesel based buses were sentoff the road and CNG buses wereintroduced, one could start seeing theblue sky over Delhi. This highlights theeffect of diesel vehicles on the airpollution in cities.This is not only the case with developingcountry like India; a similar situationprevails in developed countries like USA,Japan, Europe and our close neighbourChina. Pollution is the cause of concernespecially for urban areas in India.Hence, tight control over the emission ofdiesel commercial vehicles is absolutelyessential all over the country to protectthe health of humans, especially in urbanareas where there is heavy traffic.Through strict emission norms andeffective implementation all across thecountry, we can achieve growth of bothhealth and wealth of India. Stainlesssteels play a very useful role in themitigation of pollution from diesel/petrolpowered vehicles.A survey has revealed that over 900million people in India are affected by airpollution. The number of prematuredeaths through harmful emission keepson increasing. Deterioration of health isthe major and visible result of airpollutants which has been released byvehicular exhaust.Given below are the health impacts ofair pollution caused by vehicles:Oxides of nitrogen (NOx): This gas canmake children susceptible to respiratorydiseases in winters.Moreover, increased nitrogen loading inwater bodies, particularly coastalestuaries, upsets the chemical balanceof nutrients used by aquatic plants andanimals. Additional nitrogen accelerates“eutrophication,” which leads to oxygendepletion and reduces fish and shellfishpopulations. NOx emission in the air isone of the largest sources of nitrogenpollution in water bodies.Carbon monoxide (CO): It combineswith haemoglobin to lessen the amountof oxygen that enters our blood throughthe lungs. The binding with otherhaemoglobin in proteins causes changesin the function of the affected organs suchas the brain and the cardiovascularsystem, and also the developing foetus.It can impair our concentration, slow ourreflexes, and make us confused andsleepy.Sulphur dioxide (SO 2) : SO 2in the airis caused due to combustion of fossilfuels. It can oxidize and form sulphuricacid mist. SO 2in the air leads to diseasesof the lungs and other lung disorderssuch as wheezing and shortness ofbreath. Long-term effects are moredifficult to ascertain as SO 2is oftencombined with that of SPM.Suspended Particulate Matter (SPM):Suspended matter consists of dust,fumes, mist and smoke. The mainchemical component of SPM that is ofmajor concern is lead, others beingnickel, arsenic, and those present indiesel exhaust. These particles whenbreathed in, lodge in our lung tissues andcause lung damage and respiratoryproblemsIt is important to understand that theabove pollutants are not only affecting thehealth of human beings, but all forms oflife on the planet earth.Key Factor for Air Pollution –Diesel Commercial VehiclesBoom in industrial and agricultural outputin India, alongwith the favourable policiesof government towards farmers andfactors such as migration of populationtowards urban centres for education,jobs, medical facilities andentrepreneurial opportunities contributeto high density of population in urbancentres. To supply food, vegetables, dairyproducts, clothing and other day-to-dayneeds of urban centres with highpopulation, we need more and morediesel commercial vehicles. This is anecessary evil, which is necessary tofeed India.Impact of pollutionDiseases caused due to vehicularpollution include Asthma, Alzheimer,Strokes, Pulmonary diseases andirritation in eyes etc., depending upon theexposure to air pollution. This effectivelyshortens the life span of living beings.The effect is much greater in urban areasbecause of higher vehicular population.STAINLESS INDIA / VOL. 16, NO.3 PAGE 7Continued on page 9
Page 1: ISSN 0971-9482STAINLESS INDIAIndian
Page 5: Metro Rail Systems Sprout in Cities
Page 9 and 10: Continued from page 7Emission stand
Page 11 and 12: Continued from page 9MATERIALFACTOR

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