Tuesday, December 29, 2015

5 Awesome Advantages of Using Biogas as a Cooking Fuel





The biogas from a home biogas plant need only be compressed by placing a weight on the biogas collection and storage sack or dome over the digester tank, and possibly filtered through water, before it can be piped direct into a cooking stove,



This is truly cheap and simple to do, and the initial "fuel" or feedstock that the biogas digester is made from is simply the waste organic material produced by the family or community which runs the digester.



In rural communities in the developing nations the following list of advantages normally will apply:



1. Biogas production needs less labour than tree felling, especially when the trees are far away from the home and need to be transported.



2. Trees can be retained. Using biogas avoids the need for constantly removing trees for firewood allowing forests and woods to recover and grow, bringing shade, shelter, and forest products, plus maybe food as well.



3. Biogas is a quick, easily controlled fuel. Turn it on at a tap, light it and the heat is there to use immediately. In contrast using wood takes time to get the fire warm enough, and the fire needs attending for that period as well.



4. Biogas emits no smoke, when burnt correctly. It has no smell when pure (unless there is a leak and then you need to know of the leak, in any event). This means massively reduced eye and respiratory irritation, and extends the lives of all who use smoky wood stoves.



5. Clean pots! Yes. Pots and dishes, in fact everything remains much cleaner when using biogas as a cooking fuel instead of wood.



In reality, these are just a few of the examples where using biogas for cooking instead of wood, or even fossil fuel alternatives such as LPG in cyclinders, (which is so expensive in the developing nations), has so many advantages.



So, why aren't more people doing it? Let us read your opinions please, in the comments box below.


Sunday, December 06, 2015

Anaerobic Digestion Creates Heat but is UK Industry Overheating?

The anaerobic digestion process creates heat, and this is especially useful when it is used on the site of the digestion plant or is piped of-site to heat homes, and be used in industries near to the AD Plant. But, in another, largely political sense has it been overheating? Has there been such a large increase in the number of AD facilities in the UK that the government has decided that like the wind power and solar industries, whatever their industry experts say the industry no longer needs government subsidies to continue to grow?

In this article we will provide information on both the "heat" and the "overheating" of the UK biogas industry. First we will look at a case study where heat exchangers have been used, as part of a renewable heat system:

HRS heat exchangers creates anaerobic digestion plant for Muntons

heat exchanger in anaerobic digestion

The food sector has invested heavily in bioenergy projects such as biomass boilers and anaerobic digestion but where heat which is generated or used in one part of a process is lost rather than reused, according to HRS.

Image by cizauskas via Flickr
One of the most common situations where heat is wasted is where businesses have installed an AD plant to manage their food waste and factory by-products, said Matt Hale, international sales manager, HRS Heat Exchangers.

Heineken, Weetabix, Maltesers & Ovaltine

In most cases the primary energy output is electricity supported by Feed-in-Tariffs (FITs) which is used on site or exported to the grid,” he added.
The electricity is generated by a gas engine combined heat and power plant, but what happens to the heat? In some cases it is used for processing or heating the food factory, but often not to its full potential.
Implementing HRS heat exchanger technology, to use waste heat from one process to fuel another, could save food factories 7.5 pence per kWh² used.”
One such company is Muntons malted ingredients based in Suffolk, UK which supplies malt to Heineken beer, Weetabix, Maltesers and Ovaltine.
The firm uses 250,000 tonnes of barley to manufacture 180,000 tonnes of malt pa, which it sells the brewing and distilling industry and makes a range of malted ingredients used in food, confectionery and baking.
The company is currently putting the finishing touches to its £5.4m on-site anaerobic digestion (AD) plant. Integral to the success of the 499 kW facility is a 3 Tank Batch Sludge Pasteuriser System with Energy Recovery from HRS Heat Exchangers, which will help turn 80,000 tonnes of Muntons’ liquid malt waste into biogas and organic fertiliser.
This biofertiliser will be then be applied to local farmland, helping the company’s network of growers to produce the barley needed to make Muntons’ malt.
“For Muntons, this whole project has been about maximising efficiency. Although they have an abundance of heat, they still wanted to recapture what they could and our heat exchangers will provide at least 40% heat regeneration,” said Hale.

AD is a fast-growing industry in the UK 

He added AD is a fast-growing industry in the UK and has seen a steep rise in operational plants: from 192 in 2009 to 335 in January 2015. AD could deliver 10% of Britain’s domestic gas demands and reduce UK greenhouse gas emissions by 2%+ if industry reaches its potential: 40TWh of energy.Via HRS heat exchangers creates anaerobic digestion plant for Muntons

Gaunts Estate Anaerobic Digestion District Heating

Gaunts Estate near Wimborne, Dorset is the site of three new district heating schemes, powered by three separate anaerobic digestion plants.

Throughout the schemes, 1600m of REHAU’s flexible, pre-insulated RAUVITHERM pipework is being installed to connect the AD plants to the various farms, dwellings and countryside buildings on the estate.

The huge jump upward in the quantity of United Kingdom gas which was supplied by biogas from anaerobic digestion (AD) and landfill gas last year, has been lept upon by the UK government as evidence that there is a similar overheating of the biogas industry in the UK to that seen in solar power farms, and wind turbines, and seems to have given them an excuse to reduce subsidies. 

The degree to which the industry has been "heating up" (in other words over-achieving government targets) making Conservative politicians confident that they can save UK taxpayers money, and still achieve EU climate change targets, is shown in the paragraphs below.

Parliamentary report shows green gas heating up

In 2014, the UK produced 37 billion cubic metres (bcm) of natural gas and biogas combined; 2.6bcm of which was generated from AD and landfill. Since then the biomethane industry has quadrupled in scale, with 40 gas-to-grid plants now generating enough indigenous gas to heat over 100,000 homes or fuel around ten per cent of the UK’s bus fleet. POST estimate that UK natural gas production will fall from 2016, with biogas becoming an increasingly important part of our gas supplies. 
The POST report’s release comes a week before the Spending Review, which will set out the government’s plans for future support for biomethane, and follows a recently leaked letter from the Energy Secretary, Amber Rudd, to her Cabinet colleagues that appears to signal recognition for biomethane’s role in a sustainable UK energy mix.  
 ADBA’s Chief Executive, Charlotte Morton, commented:

The fact that green gas represented 7% of the UK’s indigenous gas supply in 2014 represents a colossal milestone for the biogas industry. And the timing could not be better as the Chancellor considers the future of the Renewable Heat Incentive, which is crucial to facilitate further growth in biomethane, in his Spending Review announcement next week.
With continued support for additional biomethane capacity, anaerobic digestion could potentially meet 30% of UK domestic gas demand.
The UK needs 20TWh more renewable heat by 2020 to meet the government’s 12% target – biomethane could deliver a third of that. via Parliamentary report shows green gas heating up | News | ADBA | Anaerobic Digestion & Bioresources Association
Has the UK government cut the biogas subsidies so hard that they kill off the young UK anaerobic digestion plant industry, and ruin the UK's, so far, good record of compliance with climate change targets? They seem not to care about removing the heat, but will the industry go too far off-the-boil?

We will report on the effects of recent UK government announcements on biogas plant subsidy reductions again in a further posting to this blog soon.