How Catalytic Converters वर्क?

There are millions of cars on the road in the United States, and each one is a source of air pollution. Especially in large cities, the amount of pollution that all the cars produce together can create big problems.

To solve those problems, cities, states and the federal government create clean-air laws that restrict the amount of pollution that cars can produce. Over the years, automakers have made many refinements to car engines and fuel systems to keep up with these laws. One of these changes came about in 1975 with an interesting device called a catalytic converter. The job of the catalytic converter is to convert harmful pollutants into less harmful emissions before they ever leave the car's­ exhaust system.
Up Next

Catalytic Converter Quiz
TreeHugger.com: Top 5 Engine Technologies
HowStuffWorks Forums: Is there a practical catalytic converter alternative?

Catalytic converters are amazingly simple devices, so it is incredible to see how big an impact they have. In this article, you will learn which pollutants are produced by an engine and how a catalytic converter deals with each of these pollutants to help reduce vehicle emissions.



VIDEO: Check out in-depth videos on pistons and 10 ingenious car parts videos.>>
Next Page
Ads by Google

Pollutants Produced by a Car Engine
catalytic converter in a car
The location of a catalytic converter in a car.

In order to reduce emissions, modern car engines carefully control the amount of fuel they burn. They try to keep the air-to-fuel ratio very close to the stoichiometric point, which is the ideal ratio of air to fuel. Theoretically, at this ratio, all of the fuel will be burned using all of the oxygen in the air. For gasoline, the stoichiometric ratio is about 14.7:1, meaning that for each pound of gasoline, 14.7 pounds of air will be burned. The fuel mixture actually varies from the ideal ratio quite a bit during driving. Sometimes the mixture can be lean (an air-to-fuel ratio higher than 14.7), and other times the mixture can be rich (an air-to-fuel ratio lower than 14.7).

The main emissions of a car engine are:

Nitrogen gas (N2) - Air is 78-percent nitrogen gas, and most of this passes right through the car engine.
Carbon dioxide (CO2) - This is one product of combustion. The carbon in the fuel bonds with the oxygen in the air.
Water vapor (H2O) - This is another product of combustion. The hydrogen in the fuel bonds with the oxygen in the air.

Are lawn mowers next?
Gallon for gallon, new lawn mower engines contribute 93 times more smog-forming emissions than new cars. It's no wonder that the EPA and the state regulators of California are trying hard to get golf ball-sized catalytic converters into lawn mower and other small engines. However, just like in the 1970s, the lawmakers are being met with a powerful lobby. Briggs & Stratton, the leading manufacturer of small engines, says that these regulations would make for an unsafe product that emits too much heat. Four smaller lawn mower engine manufacturers have refuted this charge. Briggs & Stratton also contends that the overheating could cause brush fires if the mowers are left running and sitting still. California democrats and the EPA think it has more to do with the bottom line. Pending regulations proposed in California could reduce emissions by the equivalent of 800,000 cars per day [source: Barringer].

These emissions are mostly benign, although carbon dioxide emissions are believed to contribute to global warming. Because the combustion process is never perfect, some smaller amounts of more harmful emissions are also produced in car engines. Catalytic converters are designed to reduce all three:

Carbon monoxide (CO) is a poisonous gas that is colorless and odorless.
Hydrocarbons or volatile organic compounds (VOCs) are a major component of smog produced mostly from evaporated, unburned .fuel.
Nitrogen oxides (NO and NO2, together called NOx) are a contributor to smog and acid rain, which also causes irritation to human mucus membranes.

In the next section, we'll look at exactly what goes on inside the catalytic converter.
VIDEO: Check out in-depth videos on pistons and 10 ingenious car parts videos.>>
Next Page Previous Page
Ads by Google
Low Cost Catalyst Aging
Catagen equipment, energy efficient catalyst aging & performance tests
www.catagen.co.uk
NOx reduction
For marine diesel applications Patented next generation technology
www.dansk-teknologi.dk
CO2 Removal
CO2 Removal made easy with the Molecular Gate adsorption system
www.moleculargate.com

© 1998-2011 HowStuffWorks, Inc

Advanced Biofuels

Mitsubishi Heavy Industries Develops Technology to Locally Produce Ethanol From Rice and Barley Straw
Date Posted: April 21, 2011

Tokyo—Mitsubishi Heavy Industries, Ltd. (MHI) has successfully established technology to produce ethanol for automobile fuel, satisfying the standards of the Japanese Automotive Standards Organization (JASO), from lignocellulose (soft cellulose) such as rice straw and barley straw.

Verification of the technology has been conducted as a joint project involving the government, academia, and the agricultural and industrial sectors in Hyogo Prefecture, supported by the Ministry of Agriculture, Forestry and Fisheries (MAFF), to study effective utilization of lignocellulose.

During the technological verification at a demonstration plant, the estimated fuel cost required for commercial-scale ethanol production was also confirmed to achieve the targeted goal.

Going forward MHI will endeavor to develop the results of the project into early commercialization of bio-refinery technology in cooperation with companies and organizations concerned.

The demonstration project to produce cellulosic bioethanol has been under way since 2008 jointly with the Hyogo Prefectural Government, the Hyogo Environmental Advancement Association (HEAA) and other entities.

MHI jointly with Hakutsuru Sake Brewing Co., Ltd. and Kansai Chemical Engineering Co., Ltd. was responsible for verification of the bioethanol production processes.

Initially, each of the three participating companies took charge of specific areas based on their expertise and conducted verification testing at their own research facility.

Next, starting in December 2009 the entire process to produce ethanol from lignocellulose was verified at a demonstration plant built specifically for the project at MHI's Futami Plant in Hyogo.

Rice and barley straws, the feedstocks, were provided by a local farmers association.

HEAA, the Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, and Mitsubishi Agricultural Machinery Co., Ltd. were responsible for the verification of effective technologies relating to feedstock collection, transportation and storage.

Among the various production processes, MHI was responsible for preprocessing and saccharification, Hakutsuru Sake Brewing for fermentation, and Kansai Chemical Engineering for distillation and dehydration.

For preprocessing and saccharification, MHI adopted a hydrothermal treatment system that enables continuous processing of feedstocks; MHI made improvements to the technologies, which were jointly developed with the New Energy and Industrial Technology Development Organization (NEDO).

The new system can produce the sugar component, which is the raw material of ethanol, more efficiently than by conventional methods, using only hot compressed water and enzyme.

The demonstration testing focused on the system's performance stability and continuous operatability and on optimization of the amount of enzyme to be applied.

In conjunction with the fermentation process, Hakutsuru Sake Brewing, in cooperation with Kobe University, established a technology to convert sugar originating from rice and barley straws into ethanol by use of yeasts.

The yeasts are selected from those actually in use or those bred with non genetically modified organism (Non-GMO) technology.

Kansai Chemical Engineering verified distillation and dehydration technologies for producing bioethanol that satisfies automotive fuel standards.

The technologies involve use of a new type of distillation column developed by the company which enables longer continuous operation than conventional systems, and a liquid phase adsorption type dehydration unit that enables processing with less energy than existing gas phase types.

The results of these various tests confirmed that biofuel satisfying JASO standards can be produced continuously, and they validated optimal operation conditions when using rice and barley straws as feedstocks.

At the same time, based on the verification results, the bioethanol production cost was estimated for a commercial-scale plant to be built in Hyogo Prefecture.

It was confirmed that total running costs from collection and transportation of feedstocks to ethanol production can be achieved below the target of 90 yen per liter.

The project's technologies for producing biofuel from lignocellulose have been drawing high expectations from various quarters as a means not only to provide an alternative energy source to fossil fuels, but also to resolve problems involving competition between food and energy that can trigger grain price hikes, and to make effective use of unused biomass resources that can be a source of greenhouse gas emissions such as methane.

Various obstacles including low productivity and large energy consumption for production had been confronted in this field, however, this results verified through the demonstration project make significant progress toward addressing and resolving these issues.

Furthermore, the technology for extracting sugar from lignocellulose verified by MHI has been drawing attention not only for its feasible application to ethanol production but also as a technology applicable to the production of basic material for bio-plastics.

These verification results from the demonstration plant are thus expected to attract attention globally.

MHI now plans to make the demonstration plant used in this project available to other business operators in Japan and abroad who are developing applications of feedstock material other than straw and targeting production of non-ethanol products.

Going forward the company will continue its pursuit of early establishment of technologies for commercial-scale bio-refinery, including bioethanol, and it will seek order receipts for both experimental and commercial systems based on its proprietary technologies in cooperation with companies and organizations concerned.

For more information, visit http://www.mhi.co.jp/en/index.html.

See Related Websites/Articles:

MHI

more ADVANCED BIOFUELS...
Advanced Biofuels

Oklahoma State University Nears Completion on Biosciences Research Center in Ardmore (Forbes)
Algae Biofuels Companies Diversify Into Renewable Chemicals and Other Product Markets (Forbes)
Analysis: Algae Could Solve World's Fuel Problems (Spiegel)
Canada-Israel Foundation Awards Rosetta Green Development Funding For Enhanced Biofuel Crops
Aeromexico Completes Transatlantic Biofuel Flight (Channel 6)
USDA Weekly National Biomass Energy Report
Illinois Biomass Working Group Forms to Study Near-Term Uses For Biomass in State
Pacific Northwest National Laboratory and Partners Develop New Catalyst For Biomass Ethanol Production
WA Sen. Cantwell: Pacific Northwest Poised to Lead Aviation Biofuels Industry
Codexis and Chemtex Partner to Develop Sustainable Alcohols For Household Products Market

More News



ATEC Steel

AGRA

BFJ

©2001-2011 Country Journal Publishing Co.
3065 Pershing Ct. • Decatur, IL 62526 • 800-728-7511 • Email: webmaster@grainnet.com
No portion of this site may be copied or reproduced without prior express written permission.