Article : New Biogas Opportunity

New Biogas Opportunity is Good to Digest
 

The green energy opportunities of farm waste have been interesting farmers for some years. Modern agriculture produces considerable quantities of slurry which has been stored and spread on the land as required, where of course it has continued to play its part in the cycle of production – saving costs and contributing to efficiency.

Alistair Fell of H&H Renewables

Now, thanks to pioneering work by engineers, a breakthrough in the production of biogas using small scale slurry digesters has been achieved, reports Alistair Fell of H&H Renewables, in Carlisle.
Slurry has always held a latent fascination as a potential source of fuel and has been used as such in sewage treatment works in Britain for years, however farm manure has been impractical to recover in any usable way – until, that is, the Feed-in-Tariff was introduced making it financially viable to produce biogas on farms.
Enthusiasm for anaerobic digesters [AD] was quick to bubble forth – especially as energy costs rose, and controversy began to engulf the previously untarnished image of that other form of wind energy!
In an AD plant feedstock (silage, food waste, slurry etc) goes in at one end, and methane gas is produced at the other. The use of AD on farms has been practiced in Europe for over 20 years and it is a well proven technology. The key problem is the cost of developing large scale AD, often in the range of £1-2M.
But though farmers sought other diversification opportunities to produce energy, engineers continued to work on the problem making the AD plants smaller and cheaper. Alastair Fell now reports that a breakthrough has been achieved. “There is now a commercially viable digester available on a scale small enough to work on the average farm. So at a cost of between £150K and £750K, the price begins to smell sweet as well.”read full story

Biogas From cow dung In Java, Indonesia

biogas store in polythene bag

In Java, Indonesia, people who had used firewood for cooking for a long time started using kerosene recently. But after the price of kerosene increased, some people in rural area had trouble getting enough fuel. Some had to collect firewood in the forests again. There was a concern that the forests would shrink due to tree cutting.

A village called Lembang of Java decided to use biogas instead of kerosene. Biogas is a gas generated from livestock manure or food waste through chemical reaction in the absence of oxygen. By processing livestock manure or food waste with bacteria in a closed container, a gas called methane is produced. Unlike the gases extracted from the oilfields underground, methane does not emit extra carbon dioxide (CO2) into the air when it is burned, which makes it an environmentally-friendly energy source.

In Lembang, people use plastic containers called "biodigester" (diameter 1m, length 7m). One biodigester can generate cooking gas for 1.5 families by processing about 100 kilograms of cow dung produced by one cow per week. In addition, as a byproduct, the biodigester produces about 10-20 kilograms of organic fertilizer per 100 kilograms of cow dung, which enables farmers to grow healthy vegetables without using chemical fertilizer.

By saving money for kerosene used for cooking and chemical fertilizers, more children who were once unable to go to school can receive education, and more sick people can afford adequate medical treatment. Livestock manure and food waste were mere wastes before, but now they are important sources of energy.

"What is Anaerobic Digestion?

Anaerobic digestion is a series of processes involving microorganisms that break down organic matter without gaseous oxygen. For about 150 years humans have explored how this natural process could be used to not only manage organic waste but also produce energy. The final products of the breakdown processes are biogas, mostly made up of methane, which can be used as a fuel to generate heat or electricity via a gas-powered engine. This technology is used in sewage-treatment, in the food industry, and here in New York state, especially on farms."

source: miracle-kids.net

Article: Namibia, Biogas a Good Alternative

Article: Namibia, Biogas a Good Alternative

analysis

BIOGAS has been used for over 3000 years as an effective fuel for cooking and lighting. As fossil-based fuels become scarcer and more expensive and carbon dioxide emission levels become of greater concern, the benefits and potential of biogas as a source of energy supply are being increasingly recognised.
Biogas is a mixture of methane and carbon dioxide. It is produced by the action of bacteria on vegetable/organic material in airless conditions, which is why the process is also known as "anaerobic digestion".
One of the main attractions of biogas technology is its ability to generate biogas out of organic waste that is abundant and freely available.
The potential gas production from some animal dung is highlighted by the fact that the manure from one dairy cow can produce 9kg of LPG equivalent (a small gas cylinder) in 20 days.
Applications for boigas
Biogas technology can be implemented as a decentralized sanitation solution, which provides energy security and nutrient rich pathogen free waste water which can be used for food production.
There are over 30 million operational biogas digesters in the world as at 2007.
China alone has over 25 million residential biogas systems installed - with over a million now being installed each year - as well as over 100,000 sewage treatment plants capturing biogas for conversion to useful energy.
Normally, manure that is left to decompose releases two main gases that cause global climate change: nitrous dioxide and methane.
Most household in the SADC region obtain their energy for cooking and heating from biomass. Potential biomass energy supplies include municipal solid waste, industrial residues and energy plantations.
Through the Programme for Biomass Energy Conservation, SADC in partnership with the German Agency for Technical Cooperation are promoting efficient energy-saving wood stoves in the region.
This programme promotes a switch to renewable energy sources through the introduction of biogas, solar cookers, and fuels can include crop residues.
Advantages of biogas technology
Biogas can make an important contribution to the protection and improvement of natural resources and the environment.
Slurry, a residue from the process, is a high-grade fertilizer that can replace expensive mineral fertilizers, in particular nitrogen.
The technology is ideal for effective and productive management of livestock waste.
The technology provides an efficient wet sanitary system - that enhances effective waste product disposal.
It provides an integrated system for waste treatment, energy and fertiliser production.
The use of biogas enables rural women to save time for productive agriculture, leisure and family care and welfare.
Use of biogas technology improves the standard of living and can directly contribute to economic and social development of a country.
A biogas digester can be locally produced or built, and locally operated. The cost of the technology is therefore largely independent of exchange rate fluctuations.
It is a low maintenance sanitation system which generates resources which requires no electrical and synthetic chemical inputs.
The technology has the potential to permanently employ many thousands of people should its potential be reached in the country.
This technology is feasible for small holders with livestock producing 50 kg manure per day, an equivalent of about 6 pigs or 3 cows.
This manure has to be collectable to mix it with water and feed it into the plant. Toilets can also be connected. With an optimum at 36
C° the technology especially applies for those living in a (sub) tropical climate. This makes the technology for small holders in developing countries often suitable.
Recently, our visit to Nepal included an initial set of briefings with parliamentarians and government and NGO staff, followed by five days of site visitations to various field activities.
The delegation was exposed to a range of new ideas and concepts. Some that appear suitable for introduction to Namibia's 71 communal conservancies include:
Household Biogas Plants - Nepal has pioneered an innovative approach of generating biogas that can be used for cooking in individual households, while at the same time, improving household hygiene and reducing deforestation.
A high quality biogas plant requires minimal maintenance costs and can produce gas for at least 15-20 years without major problems and re-investment.
The slurry is a clean organic fertilizer that potentially increases agricultural productivity. Domestic biogas technology is a proven and established technology in many parts of the world, especially Asia. Therefore, I advocate that the usage of domestic biogas could be the best solution in Namibia, especially in our rural areas.
http://allafrica.com/

Article: Fill the tank - with biogas from food waste

 Article: Fill the tank - with biogas from food waste

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Leftover fruit and vegetables from markets don’t always have to end up on the compost heap. Researchers in Stuttgart are developing a new system aims to turn that waste into biogas for cars.

In affluent countries like Germany, food doesn't always land on people's plate - quite often it ends up in the trash instead. A recent study found that Germans throw away an incredible 11 metric tons (around 12 million short tons) of food each year.
In Stuttgart, Germany's de facto automobile capital, researchers are trying to feed some of this waste from the local fruit and vegetable market directly into a biogas plant. They're even building a service station for cars to tank up with the gas directly at the plant itself.
With the rising prices of petrol, biogas made from food waste could be an attractive - and more sustainable - alternative.
From the market into the tank
Stuttgart's wholesalers market is the third biggest in Germany. Titus Steiger, head of a busy fruit and vegetable trading company, is one of hundreds of traders and farmers based at there.
Leafy vegetables have to be sold quickly, he told DW, within three days. "After that we have to give them away. With herbs we only have two days," Steiger said.
The Stuttgart market produces 2,000 kilograms (2,200 pounds) of green waste, or biowaste, every year. Currently, these food scraps are collected by the city and composted.
In many regions of Germany, biogas from organic waste is increasingly being used to run heating systems and produce electricity.
The new project in Stuttgart is being run by the Frauenhofer Institute for Interfacial Engineering and Biotechnology and is set to show that energy from food waste can also be used to run cars. The experiment is part of a project called Etamax, which received 6 million euros ($8 billion) from Germany's Federal Research Ministry.

In this gleaming facility, food waste is transformed into fuel

In the pilot phase, the project will be collecting leftover fruit and vegetables from the nearby central market and several cafeterias, and then fermenting it into methane.
In a two-stage process, which lasts several days, various microorganisms digest the waste, which produces biological methane. After being pressurized, it can be used to fuel vehicles that normally run on compressed natural gas.
"Food waste has high water content and low lignin and lignocellulose content. That makes it ideal for this digestive process," Ursula Schliessman, a Fraunhofer scientist, said.
Lettuce or lemons: the right mix
Karl Kübler, who heads up Stuttgart's market, said the kind of food waste can fluctuate wildly according to season.
If it's melon season, for example, and "suddenly we have a cold spell, no one buys the melons and then we have a huge quantity of melons that are thrown out all at the same time," Kübler said.
The waste even varies from day to day. Sometimes there will be more lettuce thrown away, sometimes citrus fruits - which contain a lot of acid.
This means the scientists have to balance the pH of the material for it to be digested in the fermenter. To do this, different kinds of biowaste are stored in separate containers, where the pH and other parameters are measured.
"Then we have a specially developed system to calculate how many liters of waste have to be taken from which containers and then put in with the microorganisms," said Schliessmann.
The correct balance has to be maintained so that the microorganisms have a consistent environment in which to carry out their digestion.
Nothing is wasted
After the biogas is produced, fluid residue and any bits that cannot be fermented are put to use in other projects.
The water from the digestion process, which contains nitrogen and phosphorous, is used as a nutrient for algae, which can produce oil for use in diesel engines.
The remaining residue is turned into methane using another process - so that the organic waste is completely re-used.
The next step is to get the gas into cars.
Avoiding demand for waste
Since the system runs on food waste, it does not compete in any way with the actual production of food, as is the case when the biofuel ethanol is made from maize or other crops.
Ethanol has been the subject of a lot of criticism, especially because it uses up valuable land which could be used for growing food crops. Many also question whether it takes more energy to grow the crops than is produced.
But organic leftovers are just that. Right now in the best scenario they are composted, but for biogas proponents they represent considerable source of untapped energy.
Environment groups like Friends of the Earth Germany (BUND), say it makes sense to use food waste for biogas.

Culture of waste: Worldwide, half of all food prodcued ends up in the trash

However, Berthold Friess, who heads the organization in the German state of Baden-Württemberg where the new fermenter is located, warns that technology of this kind should not be allowed to create an artificially high demand for food waste.
Studies have indicated that around half the world's food already ends up being thrown away. "The aim should really be to make sure as little food as possible is thrown away at markets," Friess said.
He also calls for the development of lighter, more economical cars and the improvement of public transport, to reduce the use of limited natural resources like oil and gas and to put less pressure on the climate.
Biogas in future energy mix
Schliessmann hopes that smaller biogas plants like this one could someday be seen in every city and play an important role in the energy mix of the future.
"The advantage of this kind of technology is that we can put it in the middle of a city where people are living because there is no smell and it is a closed system," he said.
When the plant officially starts up at the end of April, the German car company Daimler will fill up test cars with different mixes of methane gas to find out what works best.
Author: Irene Quaile and Kate Hairsine
Editor: Holly Fox

source: www.dw.de,