A “zero waste” venture to ease fuel shortage
by Rita T. dela Cruz
Volume 9 Issue No. 2
It is true that one man’s junk is another man’s treasure. In agriculture, farm wastes such as rice straw, bio-solids from vegetables, grasses, biodegradable feedstock, and manure do not immediately find themselves into the garbage as they could be potential alternative sources of fuel energy.
These agricultural wastes are being converted into biogas fuel through an anaerobic process. Biogas comprised primarily of methane and carbon dioxide which could be used as fuel for generating electricity at homes and farms particularly in remote areas in the province where electricity is limited. These could also be burned directly for cooking, heating, lighting and process heat, and absorption refrigeration.
One question remains. How to generate biogas fuel from these agricultural wastes?
Introducing the portages
The portable biogas generator or portagas was developed by a group of researchers from the Bureau of Soils and Water Management (BSWM) lead by Dr. Rogelio Concepcion and Dr. Gina Nilo with Mr. Alan Anida, Mr. Carlos Serrano, Ms. Leonora de Leon, and Mr. Victorcito Babiera.
The feasibility and development of the portagas were undertaken for five years, from 2001 to 2006.
According to Dr. Nilo, all common biogas generators have two main parts: digester (where the slurry is mix and fermented to produce the gas); and gas holder (where the gas is collected and connected to a burner for cooking or lamp for lighting).
Prior to the development of the portagas, BSWM developed four biogas generators.
The first ever model is an integrated batch type generator developed in 2000. It is called “integrated batch type” because the gas holder is not separated from the digester.
In 2001, it was modified into a split-batch type (digester and gas holder are separated) and was referred to as PortaGas Model-1 or Pm-1. It has a floating gas holder attached to a Bunsen burner for cooking.
The previous model was further developed with the coming of Pm-2 in 2002 using a surplus burner from a non-functional auto-ignition LPG stove.
Then, a more refined model, Pm-3 was developed in 2003 with a pre-fabricated cast-iron manual gas stove and simplified gas holder fittings.
Finally, the most simplified model, Pm-4, which is the upshot of the portagas. Continue reading “Portable Biogas Generator”