Gasifier Conversion of Internal Combustion Engines

(Gasifiers are also known as producer gas systems)

Problem Statement

Develop and post on the web site:

1 Good tested gasifier conversion designs for automotive and other mobile gasifiers,

2. Designs and requirements for producing good gasifier fuels from raw agricultural and/or forest products.

3. Training information on how to make, operate and maintain gasifiers and gasifier fuel processing equipment.

The designs should be such that they can be made with the skills and materials likely to be available in a small rural community.

Status – Pre-assessment Posted

A secondary objective is educating a number of people in how to make, operate and maintain gasifiers. In case of need these people could both build gasifiers and teach others how to do so.

Designs variations suitable for the resources (potential fuels) available in difference areas would be highly desirable. Example: a gasifier run on corn or a similar resource would be useful in the central part of the country where trees are in short supply? Is this possible?

Context

In this country, as in much of the developed world, food production and distribution are dependent on functioning internal combustion engines, as are other essential services. This project area is one of four petrochemical substitutes project areas that address keeping essential machinery running in the event of a disruption in the petrochemical supply. The other four project areas are: Bio-Diesel , Ethanol, Substitute Lubricants and Substitute Hydraulic Fluids .

Internal combustion engines are used in many applications and are available in large numbers. Being able to convert these to run on locally available fuels could significantly mitigate the effects of an infrastructure collapse or other problem cutting off petrochemical supplies. Gasifiers could be used to run existing farming equipment, vehicles, small factories, generators, etc.

Background

Gasifiers (sometimes called producer gas systems ) use solid fuels like wood chips, charcoal or coal to fuel internal combustion engines. They do this by extracting burnable gases, mostly carbon monoxide (CO), from the solid fuel, filtering out the solid particles and burning it in the internal combustion engine.

Producer gas systems were used in larger fixed installations in the early 1900's. During the Second World War producer gas conversions were used extensively in Europe and Asia for automotive applications (cars, trucks and tractors). There has been relatively little work on converting internal combustion engines since WW II. It time for this technology to be revisited.

During WW II some refined automotive conversions were developed in Sweden. See The making of the Källe-gasifier. Sweden continues research and testing work today as insurance against failures in their fuel supply. A variety of designs were used in Australia. A discussion of these can be found in a book reprinted by Lindsay Press (see reference 1)

There is literature on conversions of internal combustion engines to use producer gas, but most of it dates from the 1940s and little of it is in the form needed to make a conversion. Many questions remain inadequately answered. You will find a preliminary list of questions below. Some may have simple answers. Other question could be the starting point for one or more design, build, test and refine projects.

From a preliminary investigation it appears that basic producer gas conversions could be made in many farm or automotive repair shops. However, detailed information about how to do conversions of gasoline or diesel engines is limited.

Very few people in this country have actually done a conversion. To date I have only found a couple of exception to this. These are a FEMA funded effort documented in FEMA wood gas generator.pdf and an article in Farm Show Magazine (reference lost).

Methodology / Plan

There are two somewhat separable problems areas to achieving good workable designs. There are the engineering problems of developing designs and the construction/automotive problems of building and testing them.

There are a lot of guys and a few gals who enjoy building and showing off automotive stuff. Given some good designs to build and show off I think at least some of them would find it an interesting challenge. Some of these people would enjoy doing experimental work. Obtaining good designs is likely to take several recursions.

Two potential sources for the (free) engineering work are: 1. graduate students doing design work as part of their degree requirements and 2. engineers (retired or bored with their jobs) interested in a challenging real problems.

Professors, which challenges are appropriate for your students? Would working with the people building the conversion be a useful part of your students education? If desired, we will try to help find support for such efforts. We would like to either post the results of such work on the web site with appropriate credits or if you prefer post a link to it.

Engineers, are you bored or interested in keeping your head working in retirement? Work on these problems could be both interesting and satisfying.

If interested in any of the above please e-mail us at gassifier@postcollapse.com.

If a sponsor or sponsors can be found, contests might be used to promote work in this area. Fluctuating oil prices should both increase interest and make it easier to find sponsors for gasifier vehicle contests. Sponsoring this kind of contest could be excellent public relations.

Status

We are just beginning to work on this project area and a lot of help is needed.

We are looking for and collecting information on producer gas conversions and posting links or references to it. See below. If you know of good information or references please e-mail us at gassifier@postcollapse.com. Where copyrights preclude publication we will attempt to post references. Hopefully this material will be useful to those who would like to contribute by developing, building or testing designs. We hope the postcollapse.org web sites can be used share ideas, share lessons learned and coordinate activities. When good designs are developed then maybe we can find sponsors to sponsors for contests to make the technology better known.

As with each of these project areas we would like to find people to lead these efforts and if possible also technical experts to advise them.

Notes:

1. A gasifier conversion has 3 major parts:

    1. a gasifier partly burning fuel to make gas,

    2. a filter to remove solid particles and tars,

    3. an attachment to the vehicle with a gasifier carburetor.

The difficulty in building and maintaining the filter depends on both the fuel and the gasifier design. The best designs should require the least filtering.

Note that there is usually a cooler to cool the gas. This is often combined with the filter.

  1. Developing good designs suitable for different parts of the country ( with different available resources) will require design work and possibly considerable experimentation. I don't know what other farm products could be used to fuel producer gas systems where wood is not readily available. Good alternatives would be most useful in the prairie states where most of our food crops are grown and wood is in short supply. The similarity of corn and wood pellet stoves suggests that corn would be a good candidate fuel for a gasifier. Possibly someone with combustion engineering expertise could evaluate the possibility.

  2. A lot of progress has been made in both control theory and combustion engineering since most of the work on automotive gasifier was done. Some of this should be relevant to gasifier designs.

  3. Gasifiers conversions usually produce less power than the gasoline version, however supercharging can be used to boost power.

  4. Well documented designs and assembly procedures will be needed for others to make and install conversions. Clear operation, maintenance and repair manuals will also be needed to keep them running. Computer based or video training courses would be highly desirable if we can find someone to make them. Other skills will be needed to make good training material.

  5. Gasifiers can also be used for other purposes such as gas lighting and cooking. Before the widespread use of electricity many cities had piped gas from coal based gasifiers (gas works). The use of gasifiers for other than fueling internal combustion engines is discussed in the Local Infrastructure pages.

  6. Personal note from projects coordinator: As good gasifier conversion designs become documented I intend to teach some of my younger friends and relations gasifier conversion skills by having them help me to convert an old pickup truck. I think it could be a fun project as well as educational. I also intend to encourage associates and friends to undertake similar projects.

    People with the skills to build gasifiers should be much better off than most in the event of a major collapse. In hard times useful skills become even more valuable. Getting older children involved in building producer gas conversions or some of the other projects could be good for them both in the short term and long term. Such involvement should also teach safety rules. [Safety is a concern since breathing carbon monoxide, an odorless gas is dangerous and can be lethal]

Gasifier Questions:

Answers to these questions would be quite useful. Some may have simple answers, others will probably require analysis, design work and experimentation.

1. How does one convert a fuel injected engines? [all conversion information we have seen addresses converting carburetor engines most newer gasoline engines use fuel injection.] From a quick look at some fuel injected engines is seems a conversion to a duel fuel system might be straight forward.

1.cut off electricity to fuel injectors in gasifier mode

2. cut of gasifier gas inlet in the air intake path for gasoline operation.

2. How does one convert small 2-cycle engines? [many useful smaller engines, such as chain saws, are 2-cycle.] For portable devices the gasifier and filter will probably need to be separated from the engine and connected with a flexible hose. How does one inject the needed oil? (Saab had some interesting solutions for their 2-cycle automobiles, injecting the oil through the crank shaft, but that would require considerable engine modifications.)

3. How does one convert diesel engines? [An alternative to gasifiers is discussed in the Bio-Diesel project area web page.]

4. What performance is to be expected from gasifier conversions compared to an unconverted engine? (Some of the literature indicates that turbo charging or supercharging can compensate for anticipated performance losses.)

5. In scaling gasifier design for different size engines what needs to be scaled? How?

6. What range of engine sizes can a single design cover?

7. What common parts could be used for several different size engines?

8 What range of fuels could be used effectively in a producer gas system, and what must be done to adjust them for different fuels and fuel properties?.

9 What tools, instruments and techniques would be most useful to repair/adjust gasifiers?

10. How is each fuel best prepared? [ For example, the literature indicates that charcoal is the most convenient fuel for automobile gasifiers. What is the best simple way to make good appropriate charcoal?]

11. What kind of measurements should be made on fuels to assess usefulness? How are the measurements done? Moisture content is clearly a issue for most fuels.

12. How easy is it to make duel fuel producer gas/gasoline (or producer gas/diesel) engines? How does one do this?

13. Could inexpensive sensors and electronics significantly improve producer gas engine performance and or range of performance? [Can inexpensive sensors and microprocessors be used to significantly improve gasifier performance or adjust a common design to use different fuels and engine sizes? How can one improve these systems using control theory?] (If significant improvements can be made with inexpensive electronics, then some precollapse investment might be considered)

If you are interested in learning more or possibly contributing some of your time and effort please please e-mail us at gasifier e-mail. This effort can use a lot of help and I think much of it will be fun to do.

Links:

A good general discussion of gasifiers as well as a discussion of recent work is found in “ Wood Gas as Engine Fuel” published by the Forestry Department of Food and Agriculture Organization of the United Nations .

Gasifier truck conversion -- http://www.motherearthnews.com/top_articles/1981_May_June/Mother_s_Woodburning_Truck

A variety of information on gasifiers, mostly not automotive, web site of engineering company that has done a variety of gasifier work -- http://www.fluidynenz.250x.com/

 PDF of FEMA funded design -- http://www.webpal.org/webpal/b_recovery/3_alternate_energy/woodgas/fema_wood_gas_generator.pdf  

Web version of NEMA funded design (same content as above) -- http://www.gengas.nu/byggbes/index.shtml--

Kalle Gasifier - WW II design used in Sweden -- several interesting refinements of basic automotive gasifier  -- http://www.hotel.ymex.net/%7Es-20222/gengas/kg_eng.html  

References

1. "Wood gas as engine fuel" by the Food and Agriculture Organisation of the United Nations (FAO) concentrates on downdraught gasification. This is considered the best type of gasifier for fuel grade wood gas. It covers most aspects of building gasifiers for fuelling engines. The web version can be found on the FAO website at Wood gas as engine fuel (web). A PDF version can also be found at Wood gas as engine fuel (PDF)

2. "Handbook of Boimass Downdraft Gasifier Engine Systems" By T.B Reed and A. Das, US Department of Energy, Solar Energy Research Institute. Handbook

3. “ Producer as for Motor Vehicles” by John D. Cash and Martin G. Cash (Book on conversion of done in Australia) Reprinted by Lindsay Publications