<html><head><title>Re: [Digestion] Sugar feedstock</title>
<META http-equiv=Content-Type content="text/html; charset=utf-8">
</head>
<body>
<span style=" font-family:'Verdana'; font-size: 9pt;">Hello Tony,<br>
<br>
When I was running a laboratory digester at Reading University, I wanted to make it as automatic as possible. I used dissolved sugar as a "base" feed, as it could be fed as a solution through a valve controlled by a timer. I did add small amounts of fertiliser to make sure the C:N ratio was correct - between 10:1 and 30:1. (I used ammonium sulphate, a BIG mistake, as the digester generated hydrogen sulphide; ammonium nitrate is better). At low rates of feed the digester ran very well. <br>
<br>
A student also ran some tests on molasses as a feed material for a digester. When we tried to increase the loading rate, the digester went sour: too many fatty acids were generated. Acid generation works much faster than methane generation, so the feed rate must match the methane rate. Sugar digests fairly rapidly, as it is readily available to the microbes. Sugar is therefore a good additive for other feed material. <br>
<br>
So, a biogas system runs very well on sugar, but nitrogen needs to be added and the feed rate needs to be limited. There are models for designing the right size of plant (see </span><a style=" font-family:'Verdana'; font-size: 9pt;" href="http://biogas.wikispaces.com/">http://biogas.wikispaces.com/</a><span style=" font-family:'Verdana'; font-size: 9pt;"> which has links to Paul Harris's model). Increase the sugar feed rate slowly until the gas production rate does not increase at the same rate as the feed rate, then reduce the feed rate slightly and keep it at that level. <br>
<br>
<span style=" font-size: 8pt; color: #31652c;"><i>-- <br>
Best regards,<br>
David<br>
</i></span></span><a style=" font-family:'verdana';" href="mailto:davidf@kingdombio.com">mailto:davidf@kingdombio.com</a><br>
<br>
<span style=" font-family:'verdana'; color: #31652c;"><i>Wednesday, February 6, 2013, 6:35:26 AM, you wrote:<br>
<br>
</i></span><table>
<tr>
<td width=2 bgcolor= #0000ff><br>
</td>
<td width=710><span style=" font-family:'arial'; font-size: 10pt;">Hi there.<br>
<br>
I have read with keen interest about the Indian sugar/starch digester being punted by ARTI.<br>
<br>
We have access to between 200 –300kg sugar sweepings a month and am very keen to build a floating drum type digester.<br>
<br>
Does anyone have any practical experience of using stock standard sugar as a feedstock?<br>
<br>
Regards<br>
<br>
TD<br>
<br>
<br>
<br>
<span style=" font-family:'verdana'; font-size: 9pt;">-- <br>
This message has been scanned for viruses and <br>
dangerous content by <b>Pinpoint Securemail</b>, <br>
and is believed to be clean. </td>
</tr>
</table>
<br><br>
<br>
<span style=" font-family:'Verdana'; font-size: 9pt;"> ********************************************************************<br>
Dr David Fulford CEnv MEI, 15, Brandon Ave, Woodley, Reading RG5 4PU<br>
</span><a style=" font-family:'verdana'; font-size: 9pt;" href="mailto:d.j.fulford@btinternet.com">d.j.fulford@btinternet.com</a><span style=" font-family:'Verdana'; font-size: 9pt;">, Tel: +44(0)118 326 9779 Mob: +44(0)7746 806401<br>
Kingdom Bioenergy Ltd, </span><a style=" font-family:'verdana'; font-size: 9pt;" href="http://www.kingdombio.com">www.kingdombio.com</a><span style=" font-family:'Verdana'; font-size: 9pt;">, </span><a style=" font-family:'verdana'; font-size: 9pt;" href="mailto:davidf@kindombio.com">davidf@kindombio.com</a><br>
<span style=" font-family:'Verdana'; font-size: 9pt;"> Skype Identity: djfulford</body></html>