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Showing posts with label BMW7. Show all posts
Showing posts with label BMW7. Show all posts

Wednesday, January 6, 2016

Which car Hydrogen, Fuel cell or Electric that will win the race?


Automobile industry has come a long way since the time of Henry Ford. The internal combustion engine that drives the modern car is slowly but steadily evolving into an emission free engine. The carbon pollution has caused globe to warm and changed the climate and also caused respiratory illness for millions of people around the world for decades. The Carbon pollution was completely ignored in the past while other design features of the car have undergone massive changes. However, when the smog and deteriorating air quality of Delhi and Beijing was beamed around the world in our TV sets, people realized how vulnerable they are to carbon pollution. But how to eliminate the Carbon emission from our automobiles? 1.The simple answer is to substitute the fossil fuels we use every day such as Petrol and Diesel with Carbon free fuel such as Hydrogen. Hydrogen being a light gas it has to be compressed and liquefied so that it can occupy less space. However, it requires a special ‘cryogenic tank’ to store liquid Hydrogen at – 253 C. BMW has already produced a commercial vehicle and it is in the market. However, the Hydrogen dispensing stations are limited in numbers. It uses existing internal combustion engine suitably modified for Hydrogen fuel so that they can use existing infrastructure that produces their petrol engines. There is no carbon emission except for water vapour. However, Hydrogen should be generated using renewable energy sources such as solar or wind. Hydrogen generated by reformation of natural gas will still have a Carbon foot print. It can be classified as a Carbon free car depending upon how Hydrogen is generated. However, producing liquid hydrogen or filling in a cryogenic tank is not commercially feasible for individual household. Hydrogen supply will have to be a centralized filling station. BMW has recently focussing their attention towards Fuel cell car. While those early vehicles were fun to drive, they suffered from the inefficiencies of super-cooling the liquefied hydrogen, and the hydrogen vaporizing in storage. Around the turn of the century, BMW began to research the hydrogen-powered, fuel-cell electric vehicle as an alternative to the hydrogen-powered combustion engine. 2.The other alternative is to substitute fossil fuel with compressed Hydrogen that generates an electric power using Fuel cell that drives the motor and the car. Here both fossil fuel and internal combustion engine are substituted with Hydrogen fuel and Fuel cell. This is a marked deviation from a conventional car. Honda of Japan was the first to introduce a commercial car using a Fuel cell. It uses compressed Hydrogen at 70 Mpa pressure that supplies Hydrogen to PEM (proton exchange membrane) Fuel cell that generates power that drives the motor and the car. There is no emission except for water vapour. The car runs smoothly and silently because there is no mechanical engine or moving part. It is truly a Carbon free car if the Hydrogen is generated from a renewable energy source such as solar or wind. It is ideal for houses with roof top solar panels. However, one has to install a water purifier, an electrolyser, a compressor and a compressed tank for Hydrogen storage. If the Hydrogen is generated by steam reforming of Natural gas, then it will have a Carbon footprint and cannot be classified as carbon free car. Generation of Hydrogen using roof top solar panel, electrolysis and compression is possible by individual households but it involves still some risk due to the explosive nature of Hydrogen. A centralized Hydrogen dispensing is still a safer method. Toyota Mirai Fuel cell car is a new model introduced by Toyota motor Co of Japan. It too has certain additional features such as a power generator for a remote households or camps. 2.The third alternative is to eliminate fuel as well as the engine completely; instead supply power to the motor from a storage battery. Here there is no emission or noise because there is no engine or moving parts similar to Fuel cell car. However, the battery is heavy and occupies a large space and it requires frequent charging from an external power source. The power often comes from the main power grid which carries the power generated from a power station which invariably uses fossil fuel. Though there is no Carbon emission from the electric car it still has Carbon footprint. However, if the power is generated from a renewable energy source such as solar and wind then it can be classified as Carbon free car. It is ideal for houses with roof top solar panels. However, it should be connected to the power grid in parallel. Alternatively, it can be connected to a storage battery if there is no grid. The Lithium ion battery pack in Tesla Roadster weighs 990 pounds, stores 56 kWh of electric energy, and delivers up to 215 kW of electric power. Tesla battery packs have the highest energy density in the industry. To achieve this energy density, Tesla starts with thousands of best-in-class Lithium-ion cells and assembles them into a liquid-cooled battery pack, wrapped in a strong metal enclosure. The battery is optimized for performance, safety, longevity, and cost. The cells used in a Roadster employ an ideal chemistry for electric vehicles Nickel Metal Hydride (NiMH) batteries are commonly used in hybrid cars. However, a 56 kWh NiMH battery pack would weigh over twice as much as the Roadster battery. Instead, Tesla uses Li-ion battery cells which dramatically decrease the weight of the Roadster pack and improve acceleration, handling, and range.
With Lithium-ion chemistry, there is no need to drain the battery before recharging - there is no “memory effect”. Roadster owners simply "top-off" each night.However long term supply of Lithium is still an issue. Each of the above cars have their own advantages and disadvantages. However, Fuel cell cars have certain advantages over Electric cars in spite of the advancement in battery technology primarily due to the weight of the battery and frequency and time required to charge the battery. Fuel cell car has a capacity to store Hydrogen fuel as well as to generate power onsite and this advantage will go a long way to make fuel cell cars truly carbon free not only for transportation but also for stationery power generation in remote locations. A large scale deployment of renewable energy generation such as solar and wind around the world can deliver a Car that is truly carbon free. However fossil fuel power generation will continue for years to come as the new technologies are developed to generate power using fossil fuel without emitting Carbon emission such as Carbon recycling. The real winner of the car race will depend upon how a Carbon emission free power generation technology will emerge in the future. Whatever may the power technology Fuel cell will be here to stay and if a cheap alternative catalyst is developed for Fuel cell then the race will be well and truly on. (Ref : Honda, Toyota and Roadster websites)

Monday, February 27, 2012

Fuel your car with Water

This article provides an overview on Hydrogen cars and how we can generate renewable hydrogen to fuel these cars. There are two well known brands of Hydrogen based cars already in the market, BMW7 and Honda FCX Clarity models. BMW7 works on Hydrogen Internal Combustion engine fuelled by Liquid Hydrogen. It is a 6 Liters V12 engine with 191Kw capacity and 390 N of torque. It offers 100km from 50 Liters of Liquid Hydrogen with a density of about 70-80gms/lit and and offers 100kms from Gasoline of 16.7 liters. It has a capacity of 170 liters for liquid Hydrogen storage at the rear end of the car. It can run both on Hydrogen as well as on Gasoline. Liquid hydrogen has a better power density but liquefaction is a cryogenic technology and consumes power for liquefaction. The storage tank also is of special construction because Liquid Hydrogen is stored at -253C. Honda FCX Clarity car is fuel cell car fuelled by compressed Hydrogen gas. It offers 100kms for 3.5 lits of Hydrogen (at 5000 psi pressure with density at 30gms/lit.). It has Hydrogen storage of 3.92kgs kgs with a total mileage of 240miles. Increasing Hydrogen storage gas pressure up to 10000psi, the Hydrogen power density is considerably increased making it comparable with liquid Hydrogen. Moreover fuel cell car is silent while driving because there is no combustion engine. BMW is able to use their existing conventional internal combustion engine with slight modifications suitable for Hydrogen so that they can use their existing infrastructure. But Honda FCX uses proton exchange membrane Fuel cell. It is an electrochemical device that converts Hydrogen into electricity which runs the motor for transmission of power. It is similar to an electric car in which power is stored in batteries and used to drive the motor for transmission. The only difference is the power is generated in Fuel cell car as and when hydrogen is supplied whereas in Electric cars, power is drawn from stored energy from the battery. We can inject pure Hydrogen along with Gasoline, CNG or LPG to assist the combustion to save fuel consumption up to 30% and to reduce harmful emissions. The conventional gasoline cars can be fitted with water electrolyzer to generate Hydrogen using the car battery. The electrolyzer currently sold in the market is quite different. They generate ‘water gases’ and not pure Hydrogen. They electrolyze water using pulsating DC current which essentially breaks down water into Hydrogen and oxygen molecules. The complete mixture of Hydrogen, Oxygen and undissociated water molecules are injected into fuel manifold of the car. The hydrogen will assist in the process of combustion to certain extend and help save the fuel consumption of gasoline. Renewable Hydrogen is a potential source for fuelling automobiles. One can use solar panels and simple tap water to generate hydrogen gas and store them under high pressure in cylinders. We will be releasing an eBook in the near future to design a suitable Renewable Hydrogen system and install them at homes and businesses for power generation as well as to fuel two stroke engines such as scooters and bikes. Initially the book will offer DIY kits to design and install power generation for homes and businesses up to 10Kw capacity electricity generation. We will be conducting trials on two stroke engines using renewable Hydrogen to get approvals from appropriate transport authorities for safety and usage on Indian roads. Hydrogen can be safely handled as long as we take appropriate safety measures as we normally do while handling petroleum products like gasoline or butane gas. It may look like a daunting task to fuel a car with Hydrogen gas but in reality, all necessary equipments and systems are commercially available including High pressure Carbon fiber tanks fully tested and approved.