Pushing the envelope for providing power with the Puxin biogas system on Palawan Island in the Philippines

 These are children from the Pasay City slum in Manila, in the Philippines.  Their future is uncertain.  Their environment is fraught with dangers. Disease vectors from toilet and organic wastes (rotting food scraps from kitchens and cafeterias and restaurants and markets)  and indoor smoke from the burning of firewood and charcoal (for those who can afford it) and garbage (for those who can't) cause disability, suffering and mortality.  Most of the families here live without electricity; a few risk the dangers, both social and physical, of illegally tapping into city power lines just so they can have some light at night to read by.

 

 This is the American Airlines gate at Chicago's O'Hare airport, one of the busiest hubs in the world for national and international travel and commerce.  Here Emerson Electronics' Insinkerator Corporation is using its market leverage and long experience in the technical engineering and marketing of food-waste grinders to inform the public that we can "grind virtually any kind of  food waste into an unending source of electrical power for a city."  The campaign challenges our spirit of innovation and the breadth of our collective vision as a society by boldly stating on one column "It's never been done before..." and then on the next column "Consider it solved!".

How can we relate these two images...?

Solar CITIES e.V. and Chance for Growth e.V. , two German non-profit organizations based in Essen, Germany, made a joint trip in March of this year, funded by Novartis Pharmaceuticals, with an Insinkerator donated by Emerson Electronics, to the Philippines to see how we can connect the "Insinkerator-based biogas" initiative that Dr. T.H. Culhane and Dr. Sybille Culhane have been building over the past three years through their work with the National Geographic Society and the Blackstone Ranch Foundation with the medical mission that Dr. Sven Volkmuth Jacynthe Omglin Hakan Celebi Eveline Hau Dr. Christian Kories Dr. Sabine List and Shervin Setareh have been conducting in Manila, Isla Verde and Palawan Island with the Alouette Foundation over the past four years.

The goal was to create what may be one of the world's first "Medical Biogas Missions", bringing together  Medical Doctors and Urban Planners and Development Professionals and Social Welfare Specialists and Engineers, all willing to go far beyond conventional borders, both geographically and philosophically, to see how we can use what we now know about the worlds of people, animals, plants and microbes to combat disease, pollution and poverty through "probiotic" rather than "antibiotic" bacteria-based solutions.

 The journey started in this shanty town region of Pasay City where Alouette's founder, Bernard Pierquin, lived for many years, studying the problems facing the urban poor, and where he  established the Alouette headquarters.  Culhane, no stranger to living in and studying slums, stayed at the foundation building  for a week while meeting with government officials and local stakeholders, visiting the offices of Social Welfare, Finance and Customs, and arguing the case for food-waste-based energy and health improvement solutions.

 Culhane also conducted meetings at the infamous garbage dump at Payatas Hills in Quezon City northeast of Manila, where 80,000 people eke out a living recycling trash around one of the world's largest landfills in a fashion similar to the Zabaleen people of Cairo, whom  Culhane worked and lived among while getting his Ph.D. in Urban Planning, and with whom the Culhane's formed Solar CITIES.

 

 Culhane discovered that that there was a "Biogas Emission Reduction Project" being conducted with international donor support at the landfill.  Essentially what is occurring is that carbon credits are being given to the sanitary landfill facility and money has now been invested in equipment to turn the methane that the landfill generates into carbon dioxide.  The first investment was in flaring equipment so that most of the methane is simply burned on-site as it is generated. The second investment was in a biogas-burning electrical generation system, enabling about 20 to 30% of the methane emissions to be transformed during the burn into electricity used by the facility itself. "The biogas plant, commissioned [in 2008,] now produces some 100KW of electricity for internal plant operations and perimeter lights of the facility" states the Philippino government website.
Organizational leaders at the site showed Culhane encouraging plans to expand that generation capacity to as much as 50 MW in phase three, providing electricity to many of the surrounding residents.

All of this is good in its way, and it was wonderful to see Garbage trucks with signs on them saying "no source separation, no collection!", encouraging Manila's citizens to use separate bins for organic and inorganic waste and be aware of what they are putting in them. In this way the Filipino municipalities are tackling the solid waste management problem properly and aggressively.

What was missing, from our perspective, was a recognition of the greater efficiencies that can be achieved by following the lead of municipalities in Stockholm, Sweden, the UK, Australia and parts of the U.S. where it has been shown that by grinding food waste at source through devices like the Insinkerator and other kitchen-sink-based "disposals", the problem of smelly organic waste accumulating in communities is completely eliminated, fewer fossil-fuel burning, carbon emitting, noisy and expensive garbage trucks are needed and the energy balance in producing electricity through biogas can be radically improved.  Sewage systems already exist and water carriage of food waste to water treatment plants costs next to nothing given that much is gravity fed and the pumping energy is almost the same regardless of what is in the waste water.   The mix of food waste and toilet waste in the pipes and water treatment plant improves the quality and rate of the anaerobic and aerobic phases of digestion and the caloric quantity of the water entering the plant, which was rather energy poor when it was just fecal material and soaps, is radically improved so that it makes much more economic sense to capture methane and generate electricity at the water treatment plant than the landfill.

Be that as it may, we have to applaud the Payatas dumpsite for embarking on a biogas-as-renewable-energy path.

If there was one thing that we found disturbing, it was that, when visiting a family living next to the dumpsite who are pioneering the now-famous "water bottle solar light" in their shanty, we learned that the "trash recyclers" in the community used to make their own biogas at home the way we have been teaching people to do since visiting ARTI India in Pune, creating do-it-yourself biodigestors from recycled water tanks, but that they were "shut down" by the municipality and the development agencies, being told it was "too dangerous." Now forbidden to make their own fuel from their garbage, they are forced to deliver all of the organic waste they recycle to the landfill. They are told that one day they will be able to buy lower cost electricity made from the landfill gas, but for now these desperately poor people must purchase gas bottles to cook on.  From our perspective and experience, home-made biogas is not only cheaper and more reliable than bottled gas, but much safer since it is under low pressure and is produced in controllable volumes. The development agencies don't feel the same way, however,  so we hope we can continue the dialog with them and the social welfare agency  in the future so that the garbage pickers can return to their former practice of biogas innovation and slum dwellers in places like Pasay City can also join the ranks of all of us around sharing our home-scale decentralized solutions for self-provisioning.

 Since we were unable on this trip to convince authorities to let us do home scale biogas in the city, we flew to the island of Palawan to another of the Alouette Foundation sites, a school in the tranquil,  verdant and beautiful rainforest region  where abused girls from the shanty towns are given a chance to get an education and relief from urban violence. The girls go from living along a river like  this:

 To a river like this:

 Palawan Island, of course, is world famous as having been one of "National Geographic's Top 20 Destinations in the world for 2011" and is a magnet for tourists wishing to dive spectacular coral reefs, explore incredible caves and trek or zip-line through majestic tropical rainforests.

 Palawan draws tourists from all over the world, but we didn't have time to do these spectacular recreations... our "medical biogas mission" was our focus on this trip, and instead of diving into the crystal clear waters, we were diving into 2 meter deep hole we helped dig in front of the kitchen at the girl's school.

 Armed with 35  40 kilogram bags of cement Dr. Kories (left below) and Dr. Volkmuth (right below) and I began construction of a Puxin 10m3 biodigestor, using molds that we imported from China.

 We had the molds shipped along with a fiberglass family sized (2m3) digestor and biogas stoves, rice cookers, lamps and solar pumps) in a large shipping container that we had to get from China to Manila, then from Manila to Palawan harbor and then from the harbor to the village an hour into the interior of the island. The cost of the two Puxin systems and the appliances was about $8500 including the shipping from China ($5500 for the 10m3 system molds, $1000 for the family size prefab digestor and about $2000 for shipping).  But it cost an additional $2500 (and a week of negotiation) to get everything out of customs in Manila and get it shipped and trucked to the girls school. 

Word to the wise -- you need an import permit from a local non-profit to even be able to send anything to the country and then you need to spend a week getting tax exemption before you even start the shipping if you want to get the goods in duty free.  We ended up having to pay a mere 1% industrial import duty on most of the items, and that is okay (they were going to levy 15% on what they considered "domestic" goods like the biogas cookstoves and food grinders and lamps until I discovered a law that says that "if the highest value base item is taxed at 1% as an industrial or agricultural good then smaller parts that are part of the same system get taxed at the same rate), but the paper work and internal shipping still cost us thousands. For small non-profits like ours this is a giant "Ouch!"

 In any event, here is what we brought in to the island of Palawan -- a full set of Puxin molds and gas holders for the 10m3 system, a 2m3 family sized system and the relevant appliances.

In the above photograph, all the metal and fiberglass parts for the 10m3 system are displyed on the lawn in front of the school. The system comes with plates so that you can either build your biodigestor above the ground or below the ground. When you build above the ground you set up two sets of plates and pour cement between them. When you build underground you can let the walls of the hole you dig serve the same function as the outer mold plates you would use above ground to hold the cement; this means you can dig a smaller diameter hole.

 In the above photograph we demonstrate that it is valuable to set up your plates like a jigsaw puzzle before you get to building so that you can make sure you have all the parts and so you can label them for quick assembly and disassembly.  The beauty of the Puxin system is that once the cement dries in a couple of days (as little as 48 hours) you can remove the plates and use them to build another system immediately.

Above, Dr. Sven Volkmuth from Chance for Growth gets familiar with the molds which he now uses as part of his medical missions to eliminate the root causes of diseases like cholera, typhoid, dysentary and indoor smoke that plague his patients who hadn't previously had ways of dealing with the bad effects of organic and toilet waste caused infirmities and the fire and burn hazards and pollution and deforestation that come from wood and charcoal based fuels.

 The Puxin system plates go together in just a couple of hours (most of the difficulty in  building a biogas  system now that we have the Puxin  is simply the amount of time and labor it takes to dig the hole! The rest is simple).  The only tools needed to assemble the plates with the supplied metal hooks are some hammers and a crowbar in addition to a supplied steel rod.

 Assembling the frame of the fiberglass gas holder is simple.  The gas holder is the only part you need to order from Puxin once you have the molds; everything else can be obtained locally.  We purchased six 1 cubic meter gas holders, one of which goes on the top of the digestor itself and the others which can be used as extra gas storage chambers for the system so that we can store enough for continuous electricity generation.

 We painted the metal plate molds with grease to make it easy to remove them once the cement cured.

 And then jumped in the hole to start assembling.

Within a short while we had the main chamber of the digestor ready for cement pouring.

 Although Puxin told us that they have constructed thousands of systems without needing any rebar reinforcement, the local masons were concerned about shifting soils and earthquakes in their region and felt it was worth the extra time to put rebar in before pouring the concrete.

Before pouring cement on top of the "cow stomach" we placed 100mm sewer pipe sections where we wanted the feeding and effluent holes to go. We placed the feeding hole near the kitchen and the effluent hole facing the garden so we can direct the resultant fertilizer there. Every time the kids feed the digestor an equal amount of high quality fertiizer automatically goes to their garden to produce nutritious food.

 Before we finished assembling the neck/gas holder molds, we started building a wall out of concrete block inside the digestor. This addition is not in the Puxin plans but it is a Solar CITIES innovation, borne out of the idea that biogas bacteria are most efficient when they form biofilms and don't work very well floating in the tank.  We want to radically increase the surface area available to the bacteria and at the same time ensure that the methane bubbles are not impeded. Vertical walls work well for this and the holes inside the concrete blocks give not only additional surface area but refuge to bacteria protected from temperature and acidity fluctuations. Meanwhile, the vertical surface enables bacteria to live in all temperature regions of the tank; since the bottom of all water tanks is the coldest area and that is where the sludge granules form, most biogas tanks don't work very efficiently.  We want the bacteria to be able to live in the warmest regions of the tank toward the top) without having to do much or any mixing.

 With the neck assembled it was a simple matter to finish pouring the cement and then place the gas holder inside after removing the plates 24 hours later (the stomach plates need to wait 48 hours before removal).

The finished 10m3 Puxin digestor in operation, with the gas collector painted by the schoolgirls. The digestor itself is underground and the grass has been replanted over it.  Only the feed inlet (left) and the slurry outlet (right) as well as the neck of the gas holder can be seen above ground. In other installations one can dig deeper and bury the whole unit. We chose to put the neck above ground because we hit a lot of rocks below 2 meters.

There was, however, a problem with the installation -- after we left the school builders didn't quite understand the hydraulic pressure concept of the Puxin system and made the feeding inlet and fertilizer outlet to low relative to the height of the gas holder neck of the system.  Because of this there was insufficient pressure to push the gas out of the fiberglass dome gas holder.  Culhane created this animated gif in GIMP to show what the finished digester should have looked like.

The picture above shows how it should appear now.  With the gray feeding inlet raised and the blue fertilizer outlet raised, both to the same height as the gas holder neck, the water will reach the top of all three areas when the gas holder is filled with 1m3 of gas and that pressure will push the gas out to the kitchen.


The Puxin Manual  "Puxin Proposal for Household Digesters", which you can find in our facebook group "Solar CITIES Biogas Innoventors and Practitioners" gives the following information:

"

The working principle of storage tank is performed by the pressure, produced by water inside of tank.

The pressure is caused by the distance between water level of gasholder and water level of concrete tank

The pressure change when storage biogas or using biogas:

1. Change of water level when storaging biogas:

The water level of concrete storage tank is increasing; the water level of gasholder is decreasing at the same time.

2. Change of water level when using biogas:

The water level of storage tank is decreasing; the water level of gasholder is increasing at the same time

The most important point when using the storage system at the first time, is to

push the air in the gasholder out, before storage biogas, in order to avoid the biogas inside of gas holder to explode because of mixing with air and not to burn because of low concentration 

The way:

Removing the gas pipe which connects the gasholder, and then feeding water in the storage tank until above the gasholder, showing:

 

 Meanwhile, we had the family size 2.5m3 digestor to set up:

 This was a no-brainer because all it involved was having a couple of us carry it and set it in place and then fill it with a couple hundred Kgs of manure.  The hardest part was building a place for the PVC balloon gas holder to be protected from getting stepped on by dogs and keep it out of the sun. And that wasn't hard at all thanks to the presence of some orchid mounts.

 The finished family system looked like this, with the gray hose carrying the fertilizer to the banana trees.  The system came with a sulfur removal cartridge and we made our own water condensation trap out of a discarded soda bottle and a T.

 

 

 The Puxin system also came with a gas lamp -- a typical pressure kerosene camping lamp (the kind that use a gauze mantel) with a battery electric starter, so that we don't need to use electricity to light the kitchen.

 We also brought an Insinkerator Food waste grinder  (now lovingly known as a "feedstock preparation device" or "compost companion") to make the "mouth, teeth and jaws of our artificial sacred cow" digestor.  We demonstrated that the Insinkerator is  so easy to install that "even a monkey could do it! (er... providing it was a genetically engineered monkey with an enlarged cerebral cortex... ! ... but certainly it is so easy that any human child could do it! This business of making biogas at home from food scraps ain't rocket science folks!)

This monkey was rescued by the girls at the Alouette foundation after its habitat had been disturbed. Much of the remaining  rain forest is disappearing because the trees are cut for firewood or charcoal and primates and other wildlife are increasingly in danger of extinction just so that we humans can cook and bathe with hot water. Since biogas from food waste can entirely eliminate the need for firewood and charcoal, we wanted to introduce this monkey to the front end technology of its possible salvation.  "Brother monkey" Culhane says, "this Insinkerator can help protect your species and the rain forest that you love so much. Won't you join us in turning food waste and monkey poop into biogas?"  Not surprisingly the monkey was quite willing to donate everything it produced to the effort! The wacky video below shows the reaction of the monkey to all this ... (note: we were told that  if the school hadn't rescued the monkey, it would have ended up on somebody's dinner plate. We tried to convey to the monkey how much better it is is to contribute poop and food scraps to the biogas than his own skin and bones!)

 With the Insinkerator in place in the school kitchen (kindly donated by Emerson Electronics Insinkerator corporation to our Public Health and Education project)  and the lamp and cook stove and rice cooker hooked up everything was ready for the kids to start generating their own cycle of food-waste-to fuel.

 

The children were taught how the food scraps they produce every day can be used to create their own  biogas and biocompost.

In the video above we explain the health benefits of the Puxin family digestor to the Filipino child responsible for its care and maintenance.

The girls at the school generating more feedstock for their energy production system which works 7 days a week, 24 hours a day, come rain or shine!

 The girls, having helped create their own renewable-energy and fertilizer producing system and now responsible for its care, feeding and maintenance, are exciting by the prospect of being scientists and engineers who can discover and implement solutions to their own environmental and economic and health challenges.

 

 The teachers, parents, cooks and other staff,  were also given professional development training in Insinkerator-based biogas.

 

 And finally, Solar CITIES and Chance for Growth held the "First International Conference on Biogas Systems in Palawan", holding an event for the community, the social welfare division, and the press.

We discussed with everybody how much useful  solar energy is  embedded in the huge amounts of food waste we all generate, from banana peels to avocado pits to rotten tomatoes and how we can capture and make use of it...

 We talked with women's groups about how kitchens and bathrooms are the new frontiers for environmental improvements and economic opportunity because they consume the most energy (1/3 of all human consumption) and water and produce the most wastes, and we talked about how the women of the world can lead the charge to save our environments because these domains traditionally belong to them.

 We demonstrated how using a food waste grinder like the Insinkerator to increase surface area can radically improve the transformation rate of organic garbage into rich compost (with an insinkerator compost can be created in 3 to 6 days rather than 3 to 6 months!) ending soil depletion and soil infertility, and how the Insinkerator slurry in a biodigestor can be turned into liquid fertilizer in 24 hours.

 

 

 The conference participants, now armed with their  Puxin biogas system molds, can now replicate hundreds and hundreds of 10m3 community scaled digestors throughout the island for the mere cost of cement (about $300 to $400 worth per digestor), a gas holder and some plumbing supplies (about $250) and the labor to dig a hole and pour cement.  This means that for as little as  $750 each in capital costs (let us say $1000 including possible labor and transport),  groups throughout the island of Palawan can now, from their 10m3 systems,  provide up to 20 hours of cooking fuel (or 5 hours of electricity generation) every day... forever.

 Meanwhile,  Bernard and the small staff living next to the school, using the 2m3 family systems, can now cook all their meals on what just they produce from their kitchen garbage, showing that there is a biogas system appropriate for everyone at every scale.

 And when you have your first biogas meal, and observe the clean, odor-free, smoke-free flame that God helped us create  through the power of His first creations, those tiny invisible bacteria who are the alpha and the omega of this island earth, and think about the miracle of how you were able to cooperate with them symbiotically and  take something that is often considered a terrible health hazard -- the organic waste that comes from your kitchen and bathroom and routinely contaminate our air, land and water, causing the untimely death and suffering of women and children the world over -- and turn it into life and health giving heat and energy and fertilizer, you might, like us, decide to join the world-wide mission to empower families and communities through biogas-based-development.