Saturday, January 28, 2006

Biodiesel Chemistry

I have had quite a bit of conversation regarding biodiesel lately. I guess it would be appropriate to share some of it as some of you might have the same questions.

Q. At what temp will biodiesel plug my fuel filter?
A. This depends on what the biodiesel is made from. Biodiesel is made from oils/fats or triglycerides. On the right of the molecule is the glycerol and the three carbon chains attached to the glycerol are the fatty acids. Notice all bonds in the carbon chains are single bonds. This is called a saturated triglyceride. Bad stuff for your arteries and a solid at room temperature. Unsaturated triglycerides have one or more double bonds and tend to be liquids at room temperature. Biodiesel made from unsaturated oils, e.g. animal fats will form wax crystals at a lower tempterature than biodiesel made from saturated oils, e.g. canola oil.

Q. Can I use a diesel fuel treatment to prevent biodiesel from turning to jelly?
A. Companies such as Enertech and PowerService make fuel treatments for biodiesel. If you read carefully, even their best products either are designed to work on a blend of only B20 or their claims are only valid for plant-based biodiesel. How many of you know what type of oil your biodiesel was made from? The only guarantee you have is putting some fuel in a mason jar and use a thermometer and a freezer to figure out the temp where it starts to cloud up.
Q. How often do I need to change my fuel filter after I start using biodiesel?
A. I don't know. Always carry a spare fuel fiter and the tools to do the job in the trunk :) Pay attention for losses of power under acceleration.

Sunday, January 15, 2006

Tools, Tools, Tools

I don't know if any of these are still available from Volvo but...

1. Valve Depressor Tool, Volvo# 9995196 21This tool is used to depress the valves without impinging on the valve shim discs enabling removal and replacement when adjusting valve clearance. Necessary for adjusting valves. See previous posts for the Hazet version
2. Camshaft Sprocket Wrench, Volvo# 9995199 21This wrench is crucial for preventing the camshaft from moving when removing/replacing or adjusting the front or rear timing belts, or removing or replacing the camshaft front or rear sprockets. This would have been a great tool to have when I did this job.
3. Camshaft Rear Sprocket Bolt Wrench, Volvo# 9995201 21This wrench is used to gain access to the camshaft rear sprocket bolt when removing/replacing or adjusting the rear timing belt, or removing or replacing the rear camshaft sprocket. Note: I have not needed this tool to do the job.
4. Diesel Injection Pump Locking Pin, Volvo# 9995193 21Locking Pin crucial for securing Bosch diesel injection pump sprocket from rotating during R&R of cam shaft drive belt. This Locking Pin also assists in locating the general timing position of pump. Note: This pin looks shorter than the one typically sold for VW's and would probably be easier to get into the pump. On the VW, the injection pump is not against the firewall
5. Camshaft Locking Plate, Volvo# 9995190 21Used for securing the cam shaft from rotating and maintaining correct timing position during R&R of cam shaft drive belt. Easy to find this Tool
6. Diesel Injection Pump Dial Gauge Holder, Volvo# 9995194 23 Used for accurate adjustment of the Bosch diesel injection pump. This Dial Gauge Holder screws into the back of the injection pump and comes equipped with a 10cm dial indicator extension pin. Easy to find this Tool
7. Dial Indicator For use with the Injection Pump Dial Gauge Holder above. This is a precision instrument of high quality. Easy to find this Tool

Friday, January 06, 2006

Tachometer and a "Green" method of Biodiesel Production

Yesterday my tachometer decided that it would start working again :) Yahoo! I guess sometimes if you wait long enough, your car might fix itself... SoDak is still going strong and starting fine in sub-zero temps, but in desperate need of some front strut inserts.

Biodiesel made with sugar catalyst(From the journal Nature)

The production of diesel from vegetable oil calls for an efficient solid catalyst to make the process fully ecologically friendly. Here we describe the preparation of such a catalyst from common, inexpensive sugars. This high-performance catalyst, which consists of stable sulphonated amorphous carbon, is recyclable and its activity markedly exceeds that of other solid acid catalysts tested for ‘biodiesel’ production. The esterification of higher fatty acids by liquid acid catalysts such as sulphuric acid (H2SO4) is a process commonly used for biodiesel production, but it involves high consumption of energy and the separation of the catalysts from the homogeneous reaction mixtures is costly and chemically wasteful. Recyclable solid acids, such as Nafion1–4, make better catalysts, although they are also expensive and their activity is less than that of liquid acids1. Sulphonated naphthalene carbonized at 200–250 C is a solid acid catalyst that has been used successfully for ethyl acetate formation5; however, it is a soft material and its aromatic molecules are leached out during liquid-phase reactions above 100 C or when higher fatty acids are used as surfactants, so its catalytic activity is rapidly lost. We have devised a strategy to overcome these problems by sulphonating incompletely carbonized natural organic material to prepare a more robust solid catalyst. Incomplete carbonization of natural products such as sugar, starch or cellulose results in a rigid carbon material that is composed of small polycyclic aromatic carbon sheets in a three-dimensional sp3-bonded structure. Sulphonation of this material would be expected to generate a stable solid with a high density of active sites, enabling a high-performance catalyst to be prepared cheaply from naturally occurring molecules. The scheme we use to sulphonate incompletely carbonized saccharides is shown in Fig. 1. First, D-glucose and sucrose are incompletely carbonized at low temperature to induce pyrolysis and the formation of small polycyclic aromatic carbon rings; sulphonite groups (–SO3H) are then introduced by sulphuric acid (see supplementary information). Structural analysis6–8 indicates that the prepared samples consist of sheets of amorphous carbon bearing hydroxyl and carboxyl (–OH and –COOH) groups, as well as high densities of –SO3H groups. This black powder is insoluble in water, methanol, benzene, hexane, N,N-dimethylformamide and oleic acid, even at boiling temperatures. It can be moulded into hard pellets or thin flexible films by heating with 0.5–5.0% by weight of binding polymer; the two forms have comparable stability and catalytic performance. The thin films act as electrically insulating proton conductors whose properties (0.09 siemens cm1 at 50 C and 100% humidity) are comparable to that of Nafion (0.1 siemens cm1 at 80 C). High-grade biodiesel is produced by esterification of the vegetable-oil constituents oleic acid and stearic acid. The activity of our solid sulphonated carbon catalyst in this reaction is more than half that of a liquid sulphuric acid catalyst and much higher than can be achieved by conventional solid acid catalysts (see supplementary information). There was no loss of activity or leaching of –SO3H during the process, even for samples subjected to repeated reactions at 80–180 C after having been recovered by simple decantation. The activity is double that of a carbonized sulphonated naphthalene catalyst tested previously5, which decreased rapidly on recycling at 80 C. Carbon catalysts identical to those described here have also been successfully produced from carbonized starch and cellulose (results not shown). Saccharide molecules may therefore be generally suitable for preparing these catalysts, which can be used as a replacement for liquid sulphuric acid in esterification reactions. In addition to biodiesel production, such environmentally benign alternative catalysts should find application in a wide range of other acid-catalysed reactions.