BIOGAS in INTERNAL COMBUSTION ENGINE

1. S. I. Engines
The only adoption for a spark ignition engine is a gas (not gasoline!) carburetor to work at the supply pressure (just like an LPG conversion, but an evaporator would not be needed as the storage pressure is low). It is also a good idea to scrub the H2S (as it causes corrosion) and to derate the engine (unless you want to replace it each year if operating continuously).

Modification of S.I. Engine
S.I. engines can run completely on biogas, however, the engines are required to be started on petrol at the beginning, conversion of S.I. engine for the entry of biogas, throttling of intake air & advancing the ignition timing. Biogas can be admitted to S.I. engine through the intake manifold & air flow control valve can be provided on the air cleaner pipe connecting air cleaner & carburetor for throttling the intake air.
2. C.I.Engine:- .
iesel engines also need a gas carburetor and scrubbing, but require at least 10% diesel via the injectors for ignition (and cooling). The initial starting of diesel engine is done on pure diesel

Modification of C.I. Engine:–
C.I. engine can operate on dual fuel & the necessary engine modification include provision for the entry of biogas with intake air, provision of carburetor & system to reduce diesel supply, advanced injection timing. The entry of biogas and mixing of gas with intake air can be achieved by providing the mixing chamber below the air cleaner which facilitate through mixing of biogas with air before entering into the cylinder.
The arrangement is shown in fig. is largely used in stationary engine commercially available in India. The capacity of mixing chamber may be kept equal to the engine displacement volume. The pilot injection of cycle is required to be advanced for smooth and efficient running of engine on dual fuel. The admittance of biogas into the engine at the initial stage increases engine speed and therefore a suitable system reduces the diesel supply by actuating the control rack needs to be incorporated.There is a wide range of thoughts on what treatments should these biogases be subjected to before being used as fuel. Most operators simply remove the water present in the biogas, leaving it to the engine manufacturers to design engines which will cope with the impurities inevitably included in the biogas (significant maintenance costs);

other Operators are seriously evaluating maintenance costs against initial investments in biogas clean up technologies such as has been developed by Acrion Technologies (although Acrion's technologies are mainly aimed at biogas contaminant removal and separation into methane and carbon dioxide as feed stocks for a variety of commercial applications).

PRACTICAL DIFFICULTIES
To use the biogas as a fuel in SI engine there are some practical difficulties. It is not possible to compress the methane, separated from biogas by available method, because the gas could be liquefied through chilling below -161 0C. This process is adapted by installing the units required when there use of methane separated from biogas as a fuel. Since gas can not be compressed it requires large space for storage.

PERFORMANCE
1. In purification method, by reducing CO2 and moisture along H2S impurities in biogas, the engine performance is improved.
2. Effect of spark timing :-Biogas is slow burning fuel. Hence in order to get optimum engine performance, spark timing does not advance, and then combustion continues in major part of the expansion stroke. This reduces effective work done. By advancing, spark timing power is improved on low speed at partial throttle condition as well as high speed at full throttle condition.
EXHAUST EMMISSIONS
The exhaust emission contains three specific substances which contribute the air pollution, hydrocarbon, carbon monoxide &oxides of nitrogen. Hydrocarbons are the unburned fuel vapour coming out with the exhaust due to incomplete combustion. Hydrocarbon also occurring in crankcase by fuel evaporation. The emission of hydrocarbon is closely related to many design &operating factors like induction system, combustion chamber design, air fuel ratio, speed, load. Lean mixture lower hydrocarbon emission.Carbon monoxide occurs only in engine exhaust.

It is the product of incomplete combustion due to insufficient amount of air in air- fuel mixture. Some amount of CO is always present in the exhaust even at lean mixture. When the throttle is closed to reduce air supply at the time of starting the vehicle, maximum amount of CO is produced. Oxides of nitrogen are the combination of nitric oxide & nitrogen oxide &availability of oxygen are the two main reasons for the formation of oxides of nitrogen. The spark advance means lower peak combustion temperature. It causes high NO concentration in the exhaust. With biogas, co emission levels are low than that of gasoline.

Nanotechnology could clean up the hydrogen car's dirty little secret (Nanowerk Spotlight)

Nanotechnology could clean up the hydrogen car's dirty little secret (Nanowerk Spotlight)

Back in January, when the U.S. president announced his hydrogen fuel initiative and proposed to spend a total of $1.7 billion over the next five years to develop hydrogen-powered fuel cells, hydrogen infrastructure and advanced automotive technologies, he said that it will be practical and cost-effective for large numbers of Americans to choose to use clean, hydrogen fuel cell vehicles by 2020. According to the U.S. Department of Energy's (DOE) Hydrogen Program, the government's goal is to achieve "technology readiness" by around 2015 in order to allow industry to make decisions on commercialization by then. That's only eight years to go. Given where the technology is today, this goal seems very ambitious, to say the least. Nanotechnology could help speed up the journey to the hydrogen society, but it will take some sensational breakthroughs on the way. The three key areas for the vehicles (we will not touch on the infrastructure issues here) are clean - the emphasis is on clean - hydrogen production, hydrogen storage, and the fuel cell itself. We'll take a look at how nanotechnology will play a role in these areas.

First, let's get the terminology straight. Getting an internal combustion engine to run on hydrogen is not difficult (but it is difficult to get it to run smoothly). Some of the Hydrogen Vehicles on the road today still have an internal combustion engine, but one that uses either pure hydrogen or a mix of hydrogen and natural gas. True Hydrogen Fuel Cell Vehicles basically are electric cars (having a flashback to the 1970s here?) where fuel cells convert the chemical energy of a fuel – hydrogen – directly into electricity without any intermediate thermal or mechanical processes. Neat thing is that the exhaust consists solely of heat and water.

Hydrogen Production

Hydrogen fuel cells get their hydrogen either produced on-board by converting liquid fuels (gasoline, ethanol, or methanol) to hydrogen, or by using hydrogen that has been generated off-board and stored on the vehicle. Where that off-board generated hydrogen comes from is problem number 1: There are no hydrogen wells.

Hydrogen has to be produced, and that can be done using a variety of resources. The cleanest by far of course would be renewable energy electrolysis: using electricity to split water into hydrogen and oxygen; this electricity could be generated using renewable energy technologies such as wind, solar, geo- and hydrothermal power. The dirtiest, at least until highly efficient carbon capture and sequestration technologies are developed, is the gasification of coal. Of course you can also use nuclear energy to provide the electricity for electrolysis.

However, 95% of all the hydrogen produced in the United States today (and 50% worldwide), some 9 million tons annually, is produced from methane in natural gas using high-temperature steam – so-called steam methane reforming. Government researchers say that they see natural gas only as a 'near-term' solution; 'near-term' meaning the time it takes to come up with a better and cleaner solution that scales industrially. That solution doesn't exist yet.

And here is the dirty little secret: while politicians and the energy industry talk about the clean future of the hydrogen economy, the DOE's Hydrogen Energy Roadmap foresees up to 90% of hydrogen production coming from fossil fuels – coal, gas, oil – the rest mostly from nuclear power plants (why do you think the oil companies are investing hundreds of millions of dollars into hydrogen technology?). In other words: although hydrogen fuel cell cars themselves may emit nothing but water and heat, the process of powering the fuel cells with hydrocarbons will continue the economy's dependence on fossil fuels and leave behind carbon dioxide (sequestered or not), the primary cause of global warming.

The greatest challenge to clean hydrogen production is its cost. Unless government mandates the use of hydrogen or significantly increases the taxes on existing fossil-based fuels, the 'gallon/liter gasoline equivalent' (the amount of fuel with the energy content of one gallon/liter of gas) will be the measure used by drivers to decide what fuel to use. And the cheapest way today to produce hydrogen is from fossil fuels.

Nanotechnology's major contribution to the clean production of hydrogen lies in its application to solar cells and the catalysts used in water electrolysis. The holy grail here would be a highly efficient device that you fill with water, put in the sun, and get hydrogen without using any outside source of energy. Solar cells have the potential to make this dream come true. The two key issues for now are efficiency (which is low) and cost (which is high).

In one type of solar cell hydrogen is generated directly in a photoelectrochemical process that is based on the conversion of sunlight energy to chemical energy. It has been shown that nanoscale electrode materials, resulting in higher surface area to volume ratios, will increase the efficiency of the cell.

Another type of solar cell – a photovoltaic cell – produces electricity that can then be used to power electrolytic production of hydrogen from water. Experiments with nanowire arrays and other nanostructured materials have shown that they improve the efficiency of these cells.

Without going into details here – we have plenty of news articles and spotlights on this topic on our site – it is probably safe to say that nanotechnology will play an important role in building the type of highly efficient solar cells required to become a viable alternative to fossil fuel based hydrogen production.

Hydrogen Storage

Storing the hydrogen onboard that is needed to run your car's fuel cells poses another challenge. Very roughly speaking you would need about 1 kg of hydrogen to drive 100 km (or some 2.2 lbs. per 60 miles). That means you need about 5 kg/10lbs. of hydrogen to have the same average range as today's cars. Since hydrogen's density is only 1/10th of a gram per liter at room temperature, that means you somehow need to pack 50,000 liters (∼14,000 gallons) of hydrogen into your tank. There are three ways of doing this: as a high-pressure compressed gas; a cryogenic liquid; or as a solid.

Compressed hydrogen gas tanks will likely be used in early hydrogen-powered vehicles and will need to meet cost and packaging requirements to play a role across various vehicle platforms. Honda last year announced the FCX concept car that stores 5 kg of hydrogen at 5000 psi in a tank small enough to fit into a midsize car.

Rather than using thousands of psi to compress hydrogen into a tank, or cooling it down to minus 252°C (minus 421° F) to liquefy it, an intriguing alternative of hydrogen storage has led to metal hydrides, chemical hydrides, and physisorption-based storage, where hydrogen is adsorbed onto the interior surfaces of a porous material. The stored hydrogen can then be released by heat, electricity, or chemical reaction. Many metals are capable of absorbing hydrogen as well.

Nanotechnology plays an important role here. Nanomaterials have diverse tunable physical properties as a function of their size and shape due to strong quantum confinement effects and large surface to volume ratios. These properties are useful for designing hydrogen storage materials. For instance, researchers are now investigating nanostructured polymeric materials as hydrogen storage adsorbents. The new polymer adsorbent material has shown great promise in preliminary tests.

Due to their large surface areas with relatively small mass, single-walled carbon nanotubes (SWCNTs) have been considered very promising potential materials for high capacity hydrogen storage. Theoretically, they can store hydrogen up to 7.7 wt%, as every carbon atom in SWCNTs chemisorbs one hydrogen atom. In addition, the subsequent physisorption of hydrogen on the surfaces of hydrogenated SWCNTs can increase the capacity of hydrogen storage even further. However, there is some skepticism on carbon nanotube hydrogen storage due to early mistakes in experimental publications and a rational basis for high capacity hydrogen storage materials is now being developed.

Fuel Cell

Not surprisingly, a fuel cell is essentially just the reverse of an electrolytic cell: whereas electricity is used to decompose water into its constituent gases during electrolysis, in a fuel cell water and electricity are generated by the direct recombination of hydrogen and oxygen.

A major challenge for hydrogen powered cars today is the cost of the vehicle. The cost for fuel cells alone are currently hovering between $1,000 and $3,000 per kilowatt. To compete with vehicles equipped with internal combustion engines, those figures need to drop to about $30/kW. There are several kinds of fuel cells, but Polymer Electrolyte Membrane (PEM) fuel cells – also called Proton Exchange Membrane fuel cells – are the prime candidates for use in automobiles.

Both the electrolytic and the fuel cell use expensive platinum (which currently sells for about $45,000 per kilogram) as electrode material. Researchers are looking at two ways to bring the cost of catalysts down: One way to minimize platinum usage is to increase catalytic efficiency by nanostructuring the platinum metal; another way of eliminating the use of platinum altogether is by exploring the use of much cheaper non-precious metal catalysts where the nanostructured surfaces match or exceed the catalytic properties of platinum.

Nanotechnology certainly will play a major role in a future hydrogen economy. The big question is when most of this hydrogen will be generated from renewable sources and not fossil fuels. Certainly not by 2020.

Future Cars , Loremo EV: Green Egg Omelette

Future Cars
Loremo EV: Green Egg Omelette
Bavarian-based Loremo AG began in 1993 as an idea for an extremely lightweight vehicle by engineer and automotive component developer Uli Sommer. Thirteen years later the diesel-driven Loremo LS was a surprise hit at the Geneva car show

Specs:

Type: Dedicated electric vehicle

Class: 2+2 sports car

Manufacturer: Loremo AG Propulsion

system: Central electric motor

Top Speed: 106 mph (170 km/h) .

Zero-to-63: 15 seconds

Vehicle range: 95 miles

Fuel(s) : Electric

Battery system: 20 kWh Lithium-ion

Time to full battery recharge: NA Tailpipe emissions: No

Price: €30,000 ($42,900)

Availability: 2011 in Europe
The manufacturer says

"You need to crack eggs to make an omelette."

Overview.

A portmanteau for ‘low resistance mobile’, Bavarian-based Loremo AG began in 1993 as an idea for an extremely lightweight vehicle by engineer and automotive component developer Uli Sommer.

Thirteen years later, the diesel-driven Loremo LS was one of the surprise hits at the 2006 Geneva car show, despite presenting little more than the body. Although the EV represents the next stage in development for Loremo, ostensibly nothing about it beyond powertrain is supposed to change from the LS, leaving in place, among other aspects, the patented lightweight steel structure and brilliant body design.

What we like

The wing door. This is the most dynamic aspect of the vehicle's design, the so-called "gate" or wing door, which swings upward and to the front, what we ordinarily recognize as the hood. Opening the wing door also reveals a compartment for baggage or whatever else you might need to transport.
The dashboard

love minimalist cockpits and dashboards, and Loremo has crafted a work of art here, featuring nothing more than a single combined instrument panel and an optional touch screen PC.

The vehicle weight

At a mere 1,300 pounds (590 kg), the Loremo EV is just the kind of ultra-lightweight vehicle that Loremo is trying to pioneer—although it's a little strange that the EV could weigh no more than 100 lbs more than the diesel Loremo LS.

The seating configuration.

The 2+2 seating doesn't mean that four adults can fit–it's more like 2 adults in front, 2 kids in back (facing the back window); those rear seats can be folded to create trunk space. Additionally, the two bucket seats in front only adjust vertically–there's no horizontal adjustment. Rather, the driver can make adjustments to the pedals and to the steering wheel to better suit him.
What we don’t

The cost:Fast-forward to 2011; the Loremo EV is available at a local dealership. The economy has improved. There are a handful of dedicated EV's either on the market already or coming very soon. Would you drop over $40,000 on this neat little vehicle? This is double the estimated price for the company's diesel-only vehicle, and ideally needs to come down a bit to be competitive.
The provincial ambition: Loremo has all but ruled out introducing their modest line of vehicles into the US market. Right now they're only targeting Germany and the EU.

Conclusions
Loremo's participation in the Automotive X-Prize should help to raise the company's profile (they're bringing the diesel-driven Loremo LS to the challenge), and attract a whole new fan base. I hope so.
With the exception of its price, the Loremo EV has so much going for it: good performance specs, great styling, a sportscar profile with more than a measure of practicality. In short, she's attractive on almost every level. But could she be a little too innovative? As a vehicle with the potential to be one of the few mass-market ultralight vehicles that's neither an NEV nor a 3-wheeler, you have to wonder about potential competition. Without competition, Loremo may have no incentive to lower their price or increase performance. Consequently they may also have no buyers.

BY-WIRE-STEERED SYSTEM

BY-WIRE-STEERED SYSTEM

By-wire-steered system is integration of electronic devices and mechanical systems in order to improve the performance of the steering system.Recent advances in dependable embedded system technology, as well as continuing demand for improved handling and passive and active safety improvements, have led vehicle manufacturers and suppliers to actively pursue development programs in computer-controlled, by-wire subsystems. These subsystems include steer and brake-by-wire, and are composed of mechanically decoupled sets of actuators and controllers connected through multiplexed, in-vehicle computer networks.A steer-by-wire system replaces the traditional mechanical linkage between the steering wheel and the road wheel actuator (e.g., a rack and pinion steering system) with an electronic connection. This allows flexibility in the packaging and modularity of the design. Since it removes the direct Kinematic relationship between the steering and road wheels, it enables control algorithms to help enhance driver input.There is no mechanical link to the driver.

Steer- and brake-by-wire provide a number of packaging and assembly advantages over conventional subsystems. For instance, electromechanical brake-by-wire subsystems require no hydraulic fluid to store or load at the assembly plant and permit more modular assembly, thus reducing the number of parts to be handled during production. Steer-by-wire systems have no steering column and may also eliminate cross-car steering assemblies such as racks. Arguments for ‘by-Wire’ systems include production costs, packaging and traffic safety . The ‘by-Wire’ technology as in drive, brake and steer is gaining ground and is undoubtedly an automotive solution of the future.

The arguments to support such ‘by-Wire’ systems include reduced production costs and packaging advantages and improved traffic safety. Emerging drive-by- wire technologies offer new possibilities for designing the steering characteristics of road vehicles. When the mechanical link between the steering wheel and the front wheels is replaced by sensors, controllers and actuators, enormous flexibility is achieved in terms of the control device applied and in terms of the transfer function of the steering system. This offers new possibilities for optimizing the steering system for mass-produced vehicles. However, the flexibility is of even greater advantage in the area of car adjustment for drivers with physical disabilities.The transition to purely electrical steering systems will take place step by step via systems with mechanical or hydraulic backup. Development and production of the next generations of electrical steering systems up to purely electrical steering systems create high safety demands on components and systems. Reliable and safe electrical steering systems can be realized by using appropriate safety techniques for these new systems and their components combined with the know-how of safety relevant vehicle systems.

The main limitations of by-wire-steered system are the requirement of a 42 Volts car supply, high output alternator and new generation batteries.The steer-by-wire principle becomes absolutely necessary when Future innovative steering functions, such as vehicle dynamic interventions, collision avoidance, individual wheel steering, tracking assistance, automatic lateral guidance, and finally autonomous driving functions have to be implemented in a system compound of various vehicle systems.

INTRODUCTION

By-wire-steered system is an application of ‘MECHATRONICS’, which is the integration of electronic devices and mechanical systems in order to improve the performance of the system .Recent advances in dependable embedded system technology, as well as continuing demand for improved handling and passive and active safety improvements, have led vehicle manufacturers and suppliers to actively pursue development programs in computer-controlled, by-wire subsystems. These subsystems include steer and brake-by-wire, and are composed of mechanically decoupled sets of actuators and controllers connected through multiplexed, in-vehicle computer networks. There is no mechanical link to the driver.

Steer- and brake-by-wire provide a number of packaging and assembly advantages over conventional subsystems. For instance, electromechanical brake-by-wire subsystems require no hydraulic fluid to store or load at the assembly plant and permit more modular assembly, thus reducing the number of parts to be handled during production. Steer-by-wire systems have no steering column and may also eliminate cross-car steering assemblies such as racks. Arguments for ‘by-Wire’ systems include production costs, packaging and traffic safety.The ‘by-Wire’ technology as in drive, brake and steer is gaining ground and is undoubtedly an automotive solution of the future.

The arguments to support such ‘by-Wire’ systems include reduced production costs and packaging advantages and improved traffic safety (a boon for everybody involved). Emerging drive-by- wire technologies offer new possibilities for designing the steering characteristics of road vehicles. When the mechanical link between the steering wheel and the front wheels is replaced by sensors, controllers and actuators, enormous flexibility is achieved in terms of the control device applied and in terms of the transfer function of the steering system. This offers new possibilities for optimizing the steering system for mass-produced vehicles. However, the flexibility is of even greater advantage in the area of car adjustment for drivers with physical disabilities.

A steer-by-wire system replaces the traditional mechanical linkage between the steering wheel and the road wheel actuator (e.g., a rack and pinion steering system) with an electronic connection. This allows flexibility in the packaging and modularity of the design. Since it removes the directKinematic relationship between the steering and road wheels, it enables control algorithms to help enhance driver input.The transition to purely electrical steering systems will take place step by step via systems with mechanical or hydraulic backup. Development and production of the next generations of electrical steering systems up to purely electrical steering systems create high safety demands on components and systems.

Reliable and safe electrical steering systems can be realized by using appropriate safety techniques for these new systems and their components combined with the know-how of safety relevant vehicle systems.‘Steer-by-Wire’ (SbW) there exists a legislation obstacle as European regulations require a mechanical connection between the steering wheel and the wheels. The column electric power steering (C-EPS) in the Opel Astra is therefore only an electric

hybridization at steering level: the steering torque levels will increase when the car picks up speed. The “Dual drive” system in the Fiat Punto has an EPS with dual settings: the driver can activate the “city” mode and obtain gentler steering when parking. The main limitations of by-wire-steered system are the requirement of a 42 Volts car supply, high output alternator and new generation batteries.The steer-by-wire principle becomes absolutely necessary when Future innovative steering functions, such as vehicle dynamic interventions, collision avoidance, individual wheel steering, tracking assistance, automatic lateral guidance, and finally autonomous driving functions have to be implemented in a system compound of various vehicle systems