How and Why to Make Bioethanol

Ethanol (ethyl alcohol), also known as grain alcohol, is the same 'alcohol' found in all alcoholic drinks. Bioethanol is simply ethanol that has been produced using biological materials (biomass) for feedstocks. Since it relies on sunlight and photosynthesis to contribute to the growth of that biomass (plants, grasses, corn, wheat, etc), bioethanol is a renewable fuel. Bioethanol is made when biomass is converted to sugars, which are then fermented into ethanol. The process of hydrolysis seperates most of the water from ethanol, leaving an end product that is generally about 95% ethanol and 5% water. Bioethanol can be blended with conventional gasoline at any ratio, but the most common blend is E10 (10% ethanol, 90% gasoline, sometimes called Gasohol), which can be used in existing gasoline engines without modifications and without affecting vehicle warranty. Higher blends, such as E85, require a Flexible fuel vehicle (FFV).


The energy economy needs alternatives to fossil fuels, as demand rockets skyward and concern mounts over the effects of fossil fuels on climate. One possibility is bioethanol, a renewable, carbon-neutral fuel that can be used as a direct replacement for liquid petroleum gas (LPG) in internal combustion engines. Samir Bhatt gave a talk at the New Cavendish Laboratory on 26 July to describe the production of bioethanol and its possible future uses. Bhatt’s work in this area began with a project he conducted in 2004 at the University of Bath to design a bioethanol facility

from scratch, taking into account everything from material requirements, through detailed process design, to economic viability and environmental impacts. He now works as a bioinformatician at the Sanger Institute. The production of bioethanol can be broken down into five stages: feedstock growth, milling, hydrolysis, fermentation and purification. The raw material for bioethanol production is carbohydrate from plants. Any carbohydrate source can in principle be used as a feedstock. Sugar beet is the most common crop grown in the UK for this purpose. In Brazil, the world’s biggest bioethanol producer, sugar cane is the crop of choice, while the USA and Canada rely heavily on maize.
These feedstocks are processed and ground into homogeneous feed (milling) toincrease the accessible surface area of carbohydrates for hydrolysis. The hydrolysis stage breaks down the chains of complex carbohydrates such as starch into
simple sugars such as glucose. These sugars are then digested in large steel containers called fermenters by microorganisms such as yeast, which produces ethanol as a by-product of its normal metabolism. Ethanol is toxic to yeast at concentrations above about 15%, so it must be continually siphoned from the fermenter in order to maintain production. The ethanol is normally siphoned off at about 6% and must then be purified to greater than 99% to be fuel-grade for internal combustion engines. Because the profit margin for bioethanol production is small, every aspect must be optimised in order to achieve a financial return. Teams of engineers work to refine every detail of production, from recycling undigested starch to choosing the thickness of fermenter rotor blades.

With such precise optimisation, bioethanol production can and has been a success around the world. Brazil has lead the way since the creation of its 'ProAlcool' program in 1975. By 1988 a third of all Brazil’s cars were fuelled solely by
bioethanol. Ethanol/LPG blends are now widely available in the USA, where the bioethanol market is growing by around 15% per year. The USA is close to overtaking Brazil as the largest bioethanol producer.

In the UK, Tesco now sells LPG containing 5% bioethanol as standard at hundreds of petrol stations across the country, while in March Morrisons opened the nation’s first 'E85' pump, delivering a mixture of 85% bioethanol and 15% petrol. Advances in technology have improved production efficiency dramatically over the past three decades. Modern plants now take advantage of enzyme hydrolysis that improves glucose yield from complex carbohydrates, newly developed strains of yeast and bacteria that can take advantage of otherwise indigestible 5-carbon sugars such as xylose, and new
membrane technologies are making ethanol purification to fuel grade 99% quicker and cheaper. Improved efficiency,combined with expected increases in demand as fossil fuel sources become unreliable leading to higher prices, may make bioethanol an even more lucrative business in the coming years.

Indeed, the market is already growing: world production of bioethanol jumped from the energy equivalent of just over 10 million tonnes of crude oil (tonnes of oil equivalent' or 'toe') in 2002 to over 16 million toe in 2005. This is, however, still
dwarfed by total global crude oil production, which was around 4.3 billion toe for 2005. According to Futura Petroleum Ltd, bioethanol has the potential to provide 1.3 billion toe, equivalent to 30% of world crude oil consumption in 2005. Other biofuels also show great promise. Biobutanol can be produced in much the same way as bioethanol, has an energy density closer to petroleum gas and can be used in standard engines at higher concentrations than bioethanol.

No one energy source will meet the world’s needs, especially given that demand is set to grow still further. Although it is unclear how the energy market will play out over the next half-century, it seems that biofuels could play an increasingly
prominent part. David Mackay's homepage, including 'You Figure it Out', a new book on the sustainable energy crisis.

Contributed by Peter Davenport From Source http://www.bluesci.org

Read more

How to Make VCO (Virgin Cococnout Oil)

Virgin Coconut oil is everywhere these days. From cosmetics to medicines to food supplements, it is definitely a phenomenon that is here to stay. It therefore pays to gain knowledge and be familiar with virgin coconut oil.

Definition: Virgin Coconut oil is oil extracted from fresh coconut (not copra) meat by mechanical or natural means. It can be obtained with or without using heat. To protect the oil’s essential properties, the production of virgin coconut oil does not undergo chemical refining, bleaching, or deodorizing. Said to be high in vitamins and minerals, it is fit for consumption without the need for further processing.

Physical Characteristics: Pale yellow to colorless oil with a distinct taste and scent. Depending on the method used in the drying and processing, some virgin coconut oil may have a smoky flavor and slight yellowish in color. High quality virgin coconut oil should be colorless and residue free.

According to the standards set by Department of Trade and Industry-Bureau of Product Standards of the Philippines (the worlds largest exporter of coconuts), virgin coconut oil must be colorless, sediment free with natural fresh coconut scent and free from rancid odors or tastes. It is required to have a maximum of .20% moisture and volatile content to prevent rancidity and should not contain food additives. -PNS/BAFPS 22:2004 with Amendment 1:2005.

Methods Used in the Manufacture of Virgin Coconut Oil

1. Drying-Fresh coconut meat is dried to produce the oil. Low heat is used to quick dry the coconut meat.

2. Wet-milling- In this method, fresh coconut meat is not dried. The coconut meat is squeezed out to produce the milk first. The oil produced is separated from the water and solid components (which is mostly protein). It is difficult to remove the oil and various methods like boiling, fermentation, refrigeration, enzymes and mechanical centrifuge are used.

3. Fermentation- This is the traditional method. Coconut milk extracted from the fresh coconuts is fermented for 1-3 days for the oil to separate from the water and solid contents (which are mostly protein). The oil is slightly heated to reduce moisture content and be filtered.

Making Coconout Oil

1.Select only fresh and mature quality coconuts.

2.Split coconuts and collect coconut water.

3.Grate coconuts and collect coconut meat.

4.Bag the coconut meat. Use white nylon mesh bag.

5.Place bag in a Cold Press* machine. At home, you can hand press using gloves. Collect coconut milk.

6.Soak the pressed bag in coconut water and press for a second time. Collect more coconut milk.

7.Allow the coconut milk to settle undisturbed in a cabinet at 32degC for 10-17 hours.
Coconut oil will naturally separate from water and proteins.

8.Carefully collect and filter the oil and avoid mixing with the bottom water layer. The oil is colorless.

Few Tips from Cris: To filter your oil, use filter paper from the drug store. Place it on top of a funnel so that the oil will drain to your chosen container. Filter at least 2 times. Cover well and keep away from light.

article source : http://www.thevirgincoconutoil.com

Read more

Making Ice Cream Without Machine, Why Not ?

People have been making ice cream far longer than the invention of electricity so there's no reason you can't make ice cream and sorbets at home without a machine.
The advantage to using an electric or hand-cranked machine is that the final result will be smoother and creamier. Freezing anything from liquid-to-solid means you're creating hard ice crystals, so if you're making it by hand, as your ice cream or sorbet mixture freezes, you want to break up those ice crystals as much as possible so your final results are as smooth and creamy as possible.




Machines are relatively inexpensive nowadays with models costing less than $50, and yes, I've seen the ball, but if I started tossing one of those around the streets here in Paris, I'd probably get even more strange looks than I normally get. (Plus you'll need to lug some rock salt home as well.)
But not everyone has the space or the budget for a machine, so here's how you can do your own ice cream at home without a churner. I recommend starting with an ice cream recipe that is custard-based for the smoothest texture possible. You can use my Vanilla Ice Cream or another favorite, or even this Strawberry Frozen Yogurt recipe using Greek-style or drained yogurt. The richer the recipe, the creamier and smoother the results are going to be.
Ice cream made this way is best eaten soon after it's made—which shouldn't be a problem.
Making Ice Cream Without A Machine
1. Prepare your ice cream mixture, then chill it over an ice bath.
2. Put a deep baking dish, or bowl made of plastic, stainless steel or something durable in the freezer, and pour your custard mixture into it.
3. After forty-five minutes, open the door and check it.
As it starts to freeze near the edges, remove it from the freezer and stir it vigorously with a spatula or whisk. Really beat it up and break up any frozen sections. Return to freezer.
4. Continue to check the mixture every 30 minutes, stirring vigorously as it's freezing. If you have one, you can use a hand-held mixer for best results, or use a stick-blender or hand-held mixer.
But since we're going low-tech here, you can also use just a spatula or a sturdy whisk along with some modest physical effort.
5. Keep checking periodically and stirring while it freezes (by hand or with the electric mixer) until the ice cream is frozen. It will likely take 2-3 hours to be ready.
You can easily make Stracciatella ice cream with Italian-style chocolate chips:
Drizzle pure melted dark or milk chocolate (about 5 ounces, 140 g) over the almost-frozen mixture, then stir, breaking up the ribbons of chocolate as they start to freeze, to create little 'chips'.
Transfer the ice cream to a covered storage container until ready to serve.

article source :http://www.davidlebovitz.com

Read more

Industri Emping Melinjo dan Kendala yang Dihadapinya

Tanaman melinjo dapat tumbuh pada ketinggian tempat 0-1.200 m dpl. Dengan demikian, tanaman melinjo dapat tumbuh di pegunungan berhawa lembab, bisa juga didataran rendah yang relatif kering. Namun agar dapat berproduksi secara maksimal, melinjo sebaiknya ditanam di dataran rendah yang ketinggiannya tidak lebih dari 400 m dpl dan dengan curah hujan sekitar 3.000-5.000 mm/tahun merata sepanjang tahun.

Pohon melinjo sudah dapat dipanen setelah berumur 5-6 tahun. Panen dilakukan dua kali setahun. Panen besar sekitar bulan Mei-Juli, sedangkan panen kecil sekitar bulan Oktober-Desember. Sedangkan pemungutan bunga dan daun muda dapat dilakukan kapan saja. Hasil melinjo per pohon untuk tanaman melinjo yang sudah dewasa bervariasi antara 15.000-20.000 biji. Menurut petani, tanaman melinjo umur 15 tahun hasil produksi buahnya mencapai 50 kg klatak (buah yang telah dikupas kulitnya) sekali panen, berarti produksi yang diperoleh klatak 100 kg/pohon/tahun. Berbagai bagian dari pohon melinjo dapat dimanfaatkan sebagai bahan makanan. Diantaranya, daun, biji melinjo dan kulit biji melinjo sering dimanfaatkan sebagai bahan untuk sayur. Selain itu, bijinya juga dapat diolah menjadi emping.

Emping melinjo adalah sejenis keripik yang dibuat dari biji melinjo yang telah tua. Proses pembuatan emping tidak sulit dan dapat dilakukan dengan menggunakan alat-alat sederhana. Emping melinjo merupakan salah satu komoditi pengolahan hasil pertanian yang memiliki nilai tinggi, baik karena harga jual yang relatif tinggi maupun sebagai komoditi ekspor yang dapat mendatangkan devisa. Sejauh ini, emping diekspor ke negara-negara tetangga di antaranya ke Singapura, Malaysia dan Brunei. Bahkan, pasar ekspor yang potensial menjangkau Jepang, Eropa dan Amerika.

Dalam sebuah presentsi potensi agroindustri emping melinjo di suatu kabupaten, beberapa orang peserta menampakkan kegusarannya. “Emping? Wah, asam urat itu!” Tampaknya persepsi bahwa emping identik dengan asam urat sudah demikian merasuk dan menyebar ke masrakarat luas. Seorang dokter lalu mencoba meluruskannya. “Pak, asam urat itu tidak ada hubungannya dengan emping atau jeroan dan lain-lain. Asam urat itu penyebabnya metabolisme tubuh tidak sempurna. Kalori yang seharusnya dibakar oleh oksigen menjadi tenaga dan urine; karena oksigen yang masuk kurang, proses pembakarannya tidak sempurna. Akibatnya limbah tubuh yang seharusnya berupa urine dan keringat, jadinya uric acid berupa kristal yang berujung runcing. Kalau kristal ini mengendap di ginjal, jadilah batu ginjal. Kalau mengendap di tulang rawan atau otot, jadilah nyeri tulang atau otot.” Terpaksalah acara presentasi agroindustri di kabupaten itu sedikit dibelokkan ke asam urat, sekadar meluruskan presepsi bahwa emping tidak ada urusan dengan sakit seseorang. Itulah kendala pertama pengembangan agroindustri emping melinjo. Yang pertamakali akan menentang upaya demikian, justru boss-boss para pengambil keputusan yang biasanya kurang olahraga, banyak stres, pikirannya tidak bersih hingga terkena gangguan asam urat. Kalau mereka diajak berbicara tentang emping, pasti dengan segera akan menolaknya.

Melinjo (Gnetum gnemon), adalah tanaman asli Asia Tenggara, khususnya Indonesia. Habitat tumbuhan ini tersebar dari Assam (India) sampai ke Fiji (Pasifik). Tanaman ini bisa tumbuh mulai dari dataran rendah sampai tinggi (0 sd. 1.200 m. dpl.) Bentuk tanaman berupa pohon setinggi 20 m. dan berbatang lurus. Produk melinjo yang bernilai ekonomis adalah biji buah tuanya untuk emping; buah muda, bunga dan daun muda untuk sayur asam dan lodeh. Kulit buah tua pun di Jateng dan DIY memiliki nilai komersial cukupbaik untuk dikonsumsi sebagai bahan sayur. Satu pohon melinjo yang sudah berumur di atas 5 tahun dan terawat baik, mampu menghasilkan biji melinjo sebanyak 50 kg. per pohon per tahun. Dengan harga Rp 5.000,- per kg. maka dari satu pohon melinjo dpat diperoleh pendapatan Rp 250.000,- Kalau populasi tanaman dalam satu hektar 400 pohon (jarak dalam 5 X 5 m.), maka hasil dari tiap hektar kebun melinjo adalah 20 ton melinjo senilai Rp 100.000.000,- Pendapatan ini masih akan bertambah kalau kita memanen daun muda dan bunga jantannya. Sebab tanaman melinjo memang ada yang berumah satu (bunga jantan dan betina ada dalam satu pohon), ada juga yang berumah dua (bunga jantan dan betina terpisah dalam dua pohon). Jenis melinjo unggul yang selama ini banyak dikembangkan masyarakat secara komersial adalah melinjo medan yang bunga jantan serta betinanya terpisah pada pohon yang berbeda.

Kendala utama pengembangan agroindustri emping melinjo adalah kurangnya pasokan bahan baku. Dua sentra industri emping besar di Indonesia adalah Kec. Limpung di Kab. Batang, Jateng; dan Kec. Menes, Kab. Pandeglang, Banten. Irinisnya, di Kec. Limpung boleh dikatakan tidak ada tanaman melinjo. Di Menes dan Kab. Pandeglang pada umumnya, populasi tanaman melinjo masih cukup banyak. Meskipun bukan termasuk jenis melinjo unggul. Sentra-sentra emping lain yang tersebar di Jateng, DIY dan Jatim, relatif kecil jika dibandingkan dengan Limpung dan Menes. Namun kalau kita bicara populasi tanaman melinjo terbanyak, justru ada di Lampung. Sebenarnya bukan hanya lampung, melainkan seluruh pulau Sumatera. Karena pintu keluar melinjo sumatera ini adalah Provinsi Lampung, maka dikenallah melinjo sumatera ini sebagai melinjo lampung. Dari pelabuhan penyeberangan Bakauhuni ke Merak, melinjo lampung ini akan didistribusikan ke sentra-sentra emping yang tersebar di Jawa. Terutama ke Menes dan Limpung. Sebab meskipun populasi tanaman melinjo di Pandeglang bahkan Banten pada umumnya masih tinggi, namun populasi tersebut tetap tidak dapat mengimbangi permintaan industri emping. Karena suplai dari Lampung tetam sangat diandalkan oleh Menes. Hingga kadang-kadang ada hal yang tidak masuk akal. Melinjo sumatera itu sudah diangkut ke Batang di Jawa Tengah. tetapi karena ada informasi bahwa harga di Pandeglang jauh lebih tinggi, maka melinjo lampung yang sudah terlanjur masuk Jateng itu kembali dibawa ke Banten.

Sentra industri emping di Menes memang cukup besar. Ekspor ke Timur Tengah dan Eropa tersendat bukan karena kurangnya permintaan, tetapi justru karena pasokan melinjo segar yang selalu tertinggal. Para produsen dan padagang emping sendiri memang kurang begitu bergairah untuk melayani permintaan ekspor. Sebab, “main di pasar lokal pun masih sangat longgar, menguntungkan dan tidak repot.” Selain itu memang ada perbedaan jenis emping antara pasar lokal dengan ekspor. Pasar lokal lebih menghendaki emping tipis berukuran kecil (@ 2 – 3 biji melinjo). Sementara pasar ekspor menginginkan emping setengah utuh yang hanya terdiri dari satu biji melinjo dan dalam kondisi siap konsumsi. Kerepotan untuk melayani pasar ekspor memang sangat beralasan. Eksportir dari Menes yang mengirim ke Timur Tengah dan Eropa, sebenarnya masih dalam volume yang sangat kecil berupa emping tipis. Yang akan mengkonsumsi emping demikian hanyalah bangsa kita sendiri yang sedang merantau menjadi TKI atau para mahasiswa kita yang sedang belajar di Eropa sana. Karenanya persyaratan standar mutu produk lalu menjadi kurang penting. Kalau kita serius melayani permintaan emping setengah utuh tersebut, maka persyaratan standar mutu produk (Codex) dan standar Sanitary serta Pythosanitary (SPS) menjadi sangat penting. Adanya persyaratan yang ketat inilah antara lain yang juga menjadi alasan keengganan pelaku emping kita untuk melakukan ekspor.
Kendala psikologis dari para penentu keijakan (soal asam urat); kendala pasokan bahan mentah dan kendala persyaratan mutu (teknik produksi emping); adalah tiga permasalahan yang telah menghambat pertumbuhan agroindustri emping di Indonesia. Tentu ada pertanyaan, seberapa strategiskah komoditas ini bagi bangsa kita? Kita tahu bahwa masing-masing bangsa pasti memiliki komoditas unggulan yang menjadi semacam “trade mark” bagi bangsa tersebut. Misalnya saja Perancis unggul pada komoditas wine (anggur), parfum dan bumbu. Belanda dikenal melalui bunganya, dengan tulip sebagai bunga nasional mereka. Thailand dikenal oleh dunia luar karena durian monthongnya. Padahal anggur yang dibanggakan oleh Perancis sebenarnya berasal dari lembah sungai Tigris dan Euphrat. Bahan baku parfum dan bumbu Perancis kebanyakan dari Italia, India, dan Indonesia. Durian monthong yang dibanggakan Thailand sebenarnya berasal dari Kalbar. Lalu apa produk agroindustri kebanggaan Indonesia? Jambu air kita telah lolos hingga sekarang bisa dibudidayakan dengan sangat baik oleh Taiwan. Belimbing kita justru berkembang di Malaysia. Melinjo adalah komoditas yang saat ini hanya berkambang baik di Indonesia. Tidak di India dan Srilanka, tidak pula di negara Asean lainnya. Kalau kita menyia-nyiakannya, bisa saja suatu ketika justru Vietnam yang diam-diam mengembangkannya lalu tahu-tahu mereka sudah bisa memproduksi emping berkualitas tinggi untuk ekspor.

Kasus “tercurinya” komoditas unggulan ini, bukan hanya monopoli Indonesia. Timur Tengah (negara-negara Arab) selama dikenal sebagai penghasil produk-produk dari unta. Mulai dari karpet (bulu unta), daging unta dan minyak samin (dari susu unta). Selan itu Timur Tengah juga identik dengan minyak zaitun (olive oil) dan kurma. Namun mereka tidak mengembangkannya dengan serius karena tiba-tiba ada rejeki minyak dan sibuk perang. Tahu-tahu sekarang ini mereka harus mengimpor daging dan susu unta dari Australia. Karena di negeri ini unta bukan hanya sudah bisa diternak dengan sangat intensif, tetapi juga sudah menjadi liar dan hidup bebas di padang gurun. Australia juga sudah mampu mengembangkan kurma unggul yang dalam waktu 2,5 tahun bisa mulai berbuah. Zaitun pun, sudah bisa ditanam di Australia dalam skala yang untuk ukuran Eropa Selatan sudah sangat besar. Namun Australia sendiri juga kecurian makadamia. “Nut” asli Australia ini telah dikembangkan dan diproses serta dikemas dengan cukup baik oleh Afrika Selatan dan Hawaii. Dan buah kiwi, sebenarnya milik RRC. Kiwi adalah buah hutan yang tombuh liar di Cina timur laut. Namun tahu-tahu buah eksotis ini bisa menjadi “trade mark” nya New Zaeland. Meskipun Indonesia sendiri sebenarnya telah “mencuri” karet dan sawit yang sebenarnya milik negara-negara Afrika dan Amerika tropis.

Kembali ke masalah melinjo, pertama-tama yang harus dilakukan adalah memutus hambatan psikologis dari para penentu kebijakan. Kalau beliau anti emping karena menderita sakit asam urat, bukan berarti penanaman melinjo harus dilarang dan industri emping berhenti. Kedua, pengembangan areal malinjo secara besar-besaran layak untuk dilakukan oleh Pemkab dan Pemprov. Para penangkar benih di Pekalongan, Lampung Tengah, siap dengan melinjo medannya yang unggul dalam jumlah jutaan batang per tahun. Balai Besar Industri Hasil Pertanian (BBIHP) di Bogor telah siap untuk mendisain mesin-mesin sederhana yang bisa memproduksi emping setengah utuh. Pasar sejak dulu sudah siap untuk menampungnya. Namun istilah “pasar yang sudah sejak dulu siap untuk menampungnya” ini jangan diartikan secara sederhana. Kenmudian pertanyaan yang muncul adalah, siapa yang memerlukan, berapa volumenya, mana teleponnya dan sebagainya. Sebab pengertian pasar dalam konteks ini adalah adanya peluang kebutuhan emping. Tetapi siapa yang akan menjadi importir di Belanda, di Timur Tengah, di Hongkong dan lain-lain, masih perlu penggarapan yang akan makan waktu, biaya dan juga tenaga. Yang disebut sebagai “pasar” di sini bukan sesuatu yang sudah ready stock hingga kita tinggal telepon, kirim barang dan uang ditransfer.

Agroindustri emping adalah bisnis yang sangat-sangat padat karya. Mulai dari panen, pengupasan kulit buah, proses pembuatan emping, pemasakan (oven) dan pengemasan, semuanya memerlukan tenaga kerja dalam jumlah yang sangat banyak. Memang agroindustri ini juga memerlukan modal besar. Namun nilai investasi tersebut relatif kecil jika dibanding dengan jumlahtenaga kerja yang bakal bisa diserap olehnya. Lain dengan aroindustri udang yang sangat padat modal. Dalam kondisi ekonomi Indonesia yang masih sangat susah dewasa ini, kita tidak perlu harus menunggu uluran tangan IMF atau World Bank sambil tidur-tiduran atau sibuk saling menyalahkan. Melinjo adalah komoditas yang sangat strategis bukan hanya untuk menghidupkan perekonomian rakyat, melainkan juga untuk prestise bangsa.

sumber : www.bi.go.id
http://foragri.blogsome.com

Read more

Making Biogas From Human Waste ? Why not

Biogas is generated when bacteria degrade biological material in the absence of oxygen, in a process known as anaerobic digestion. Since biogas is a mixture of methane (also known as marsh gas or natural gas, CH4) and carbon dioxide it is a renewable fuel produced from waste treatment. Anaerobic digestion is basically a simple process carried out in a number of steps that can use almost any organic material as a substrate - it occurs in digestive systems, marshes, rubbish dumps, septic tanks and the Arctic Tundra.

Humans tend to make the process as complicated as possible by trying to improve on nature in complex machines but a simple approach is still possible, as I hope you see in some of the links below. As methane is very hard to compress I see its best use as for stationary fuel, rather than mobile fuel. It takes a lot of energy to compress the gas (this energy is usually just wasted), plus you have the hazard of high pressure. A variable volume storage (flexible bag or floating drum are the two main variants) is much easier and cheaper to arrange than high pressure cylinders, regulators and compressors.
Human Waste as a Resource
Treating human waste through Anaerobic Digestion is an incredibly ethical sanitation technology. Anaerobic Digestion occurs in biodigesters and produces a fuel (biogas), removes Biochemical Oxygen Demand (BOD) from sewage, conserves nutrients (especially nitrogen compounds) and most importantly reduces pathogens. Human waste damages the environment because it is loaded with BOD, nutrients, and anthropozoonotic diseases. This can cause a host of environmental problems that can lead to ecosystem collapse such as rendering a water body uninhabitable for many organisms. Untreated sewage causes algal blooms, red tide, and so called dead zones. Humans also suffer from untreated sewage (also called black water). Waterborne disease transmitted through human excrement is a leading cause of death worldwide, especially in the so-called developing world. Some diseases caused by untreated human sewage are Cholera, Typhoid fever, Paratyphoid fever, Salmonella, Dysentery, Gastroenteritis, Leptospirosis, Meningitis, Hepatitis, and various parasitic diseases.
The amount of biogas that can be yielded from human waste is limited in comparison with livestock manure and other feedstocks. Are stomachs are just too efficient! David House states in his excellent book that 1000 lbs of humans produces about 0.6 cubic meters of biogas (enough cooking fuel for about 1 to 2 persons). But that amount quickly adds up, please reference the internet for example projects especially in Rwanda, India and Thailand.
Untreated sewage, along with causing a prevalence of disease, developing countries are also disposing of valuable nutrients in places where fertilizers aren’t available. Biodigesters turn waste into a biofertilizer. There is also a major flaw in the sewage treatment systems of developed countries where enormous amounts of energy are used to aerate and treat sewage; Anaerobic Digestion treats sewage and also produces energy rather than consumes it. This article discusses considerations for human waste treatment and various options are outlined.
Important! Considerations
A handful of considerations need to be made for treating human waste. There are IMPORTANT disease related issues and some common physical considerations. The number 1 issue is handling human waste. Operators that handle human waste without any precautions will inevitably get sick. The waste handling process must consider the handlers. Ideally a waste treatment system will eliminate any direct handling by humans.
Typical biodigester effluent is NOT sterile. Anaerobic digestion creates a competitive environment where pathogens are out competed by non-infectious microorganisms and therefore are edged out in terms of populations. This means that pathogens are REDUCED, but not entirely eliminated. However, studies in thermophilic biodigesters (45-55 degrees C) have shown a much greater reduction of pathogens than in ambient temperature and lower temperature biodigesters (see biodigesters capable of controlling pathogens section). A waste treatment system needs to address the issue of disease during the process via pre or post treatment or the effluent needs to be disposed of accordingly.
One common consideration in designing biodigesters to fit into an already existing system is that usually human excrement is heavily diluted to facilitate movement. Toilet flushes consume large volumes of water (range from 1.3 to 2.5 gallons but about 2 gallons in the US) and designing a biodigester with for example a 30-day hydraulic retention time (HRT) for treating flushed waste requires a very large volume biodigester at a 2 gallon per flush dilution. There are biodigester designs, however, that can handle an HRT, or the amount of time a biodigester retains a waste, of only a few hours. These designs are sludge retaining reactors such as an Upflow Anaerobic Sludge Blanket (UASB) and even better performing Fixed Film Reactors. One last important factor to consider is ammonia toxicity as human waste has been reported to have a low C: N ratio. This problem can be solved via dilution and co-digestion of a carbon rich feedstock such as molasses. Animal waste is inherently safer to treat then human waste because they tend to carry less human pathogens, though consideration for some manure born pathogens ought to be made as well.
Treatment Methods: Heat Pre-treatment
During this process human excrement would be pasteurized to 70 degrees C before entering the biodigester. This would be done best before dilution to reduce energy costs and can be done using waste steam, passive solar heating, or direct combustion of biogas or any other fuel source. The process would make more of the human excrement available for Anaerobic Digestion and would in fact likely increase the amount of biogas produced. Heat pre-treatment can also lower the HRT. Sterilization upfront will deal with any pathogen related effluent issues down the line and produce a biofertilizer for comestible (fit for human consumption) crops.
Treatment Methods: Treatment through Retention
Very long retention times for sewage have the ability to virtually destroy pathogens. The amount of time human excrement should be retained varies. In a very warm climate you may want to retain the waste for 60-90 days, however in cold climates (20 degrees C and below) 150 or more days of retention are recommended. Retention time can be controlled via the biodigester HRT or by holding the effluent for an additional period of time. The option that is the most economic should be considered as well as safety factors such as the access to holding tank and any other issue that involves potential exposure to humans and animals. Safety Warning: Retention methods to destroy pathogens should be confirmed by lab results before adoption.
Treatment Methods: Post Treatment and Sterilization
Biodigester effluent may also be treated in a secondary treatment phase such as Ultrafiltration, Ultraviolet Light (UV), a Treatment Wetland, Composting, or Aerobic Treatment. Ultra filtration consists of running the effluent through a membrane that only allows solubles to pass through. At the moment this technology is more likely to be used in the developed world but appropriate solutions using materials such as mangroves and other plants might be used. Ultrafiltration is practical for concentrated wastewaters that have had most solids settled out. UV treatment is a common water treatment technology however may only be practical for dilute effluents where turbidity is not an issue. A treatment wetland provides additional treatment as well as habitat for wildlife. Essentially a movement gradient is created and planted with wetland plants that facilitate nutrient and pathogen removal. This is the way wastewaters, such as storm runoff, are naturally treated in the environment. A composting process maybe allowed used to treat the effluent however it must first be dried to facilitate aeration, which is land and energy intensive. Care must be made to ensure that no one breathes in the dust from the fresh effluent during this process. The effluent may also go through an aerobic treatment process to polish the effluent however this is expensive, intensive, and removes nutrients from a productive system. Other waste treatment options may include sand filters and clarifiers.
Treatment Methods: Biodigesters Capable of Controlling Pathogens
As previously alluded to, some biodigester processes are able to control virtually all the pathogens found in sewage. These are thermophilic biodigesters, phase biodigesters, and staged biodigesters. In a thermophilic biodigester the environment within the biodigester is so hot that many pathogens are unable to survive. The environment is also far more competitive than in a regular biodigester. Pathogens are usually acclimated and most happy around body temperature. Fortunately many of the organisms capable of carrying out Anaerobic Digestion are thermophiles, or heat loving organisms. However caution must be made with the previously mentioned ammonia toxicity, as thermophilic biodigesters are far more sensitive to this issue than ambient and lower temperature biodigesters. A phase biodigester separates the respective phases that material must undergo during the anaerobic digestion process. Organic material undergoes hydrolysis, acidogenesis, acetogenesis, and methanogenesis. Essentially a container can facilitate the conversion of organics to solubles (hydrolysis), the production of acids (acidogenesis and acetogenesis) or methane production (methanogenesis). In phase Anaerobic Digestion two or more containers are used to separate the phases. This can be done physically (removing organics as they are hydrolysed), chemically (inhibiting methane production or buffering acids to a pH where methanogenesis can occur) or biologically (acidifying the first reactor(s)). If a reactor is allowed to acidify to inhibit methane production the low pH will also create an extreme environment where some pathogens are unable to live. After an acidic environment they will be introduced to a methane-producing environment that additionally removes pathogens through microbial competition. A two-phase biodigester capable of eliminating pathogens might have an acidifying first tank, which is then fed into a thermophilic, methane producing second tank. Staged biodigesters can work in the same way by changing the competition mechanisms in various stages (reactors) though still not quite separating the phases.
Applying Effluent
Completely eliminating pathogens is not necessary when adequate care is given to applying the effluent. Biodigester effluent that still contains pathogens can be applied into subterranean leachfields (with a clarifier), used for non-edible crops and in some cases forage crops, and applied directly to land. However all these things require safety considerations. The amount of human exposure needs to be taken into consideration. Groundwater and water body contamination are all potential threats to releasing effluent not completely void of pathogens into the environment. Direct land application needs to take direct exposure into account such as use of land by children and adults. Non-edible crops are another option and also allow for nutrient capture. Crops could include energy crops, biomass production, and many others. Exposure to humans however is again a risk that must be accounted for. The simplest and safest way to dispose of effluent is to simply inject it in an already existing sewer system.
Conclusion
Biodigesters offer a variety of benefits to the person interested in ethical treatment of human waste. The most important consideration, which has not necessarily always been effectively managed, is the danger pathogens in human waste pose to health. These systems are scalable from the household, community level to the larger industrial scale applications. Successful applications can be found worldwide and as well as in history. Best of all, Anaerobic Digestion offers to turn waste into a resource.
Further Reading
Bitton G. Wastewater Microbiology. 3rd Ed.Wiley-Liss 2005
van Haandel, A.C., Lettinga, G. Anaerobic Sewage Treatment: A Practical Guide for Regions with a Hot Climate J Whiley 1994
House, D. The Complete Biogas Handbook 3rd Ed 2007 www.completebiogas.com
Speece, R. E. Anaerobic Biotechnology for Industrial Wastewaters Archae Press 1996

article source : www.appropedia.org

Read more

How to Make Bioetanol From Cassava

Bioethanol is simply ethanol that has been produced using biological materials (biomass) for feedstocks. Since it relies on sunlight and photosynthesis to contribute to the growth of that biomass (plants, grasses, corn, wheat, etc), bioethanol is a renewable fuel. Bioethanol is made when biomass is converted to sugars, which are then fermented into ethanol. The process of hydrolysis seperates most of the water from ethanol, leaving an end product that is generally about 95% ethanol and 5% water. Bioethanol can be blended with conventional gasoline at any ratio, but the most common blend is E10 (10% ethanol, 90% gasoline, sometimes called Gasohol), which can be used in existing gasoline engines without modifications and without affecting vehicle warranty. Higher blends, such as E85, require a Flexible fuel vehicle (FFV)

Developed countries have developed alternative energy that can replace the role of petroleum and natural material resources (especially minerals) that functions as a fuel. Petroleum reserves dwindling due to increasing population needs and the bombast of the world (only China has a population of 1 billion ...) is the driving factor in giatnya scientists seeking new energy sources renewable, cheap and safe for the environment (especially those derived from vegetable ).

Some alternative fuels popular is biodiesel, biogas, biofuels, hydrogen and nuclear energy. Biofuel is one derived from biomass. Biofuel is fuel derived from plants or animals, usually from agriculture, the remaining solids are also of forest products.

Let's see biofuels, especially ethanol. Through the process sakarifikasi (complex sugar solution into simple sugars), fermentation, and distillation, crops such as corn, sugar cane and cassava can be converted into fuel.

Incidentally some time ago found a way of making ethanol from cassava is applied by Mr. H Soerawidjaja Tatang. The following processing capacity of 10 liters per day:

1. 125 kg of peeled fresh cassava, all kinds of dapal utilized. Clean and cut up small size.

2. Dry cassava which has been chopped up to a maximum water content of 16%. Just a dried cassava into cassava. Aim to be more durable so that producers can save as a raw material reserves

25 kg of dried cassava 3.Masukkan into the eel tank stainless steel 120-liter capacity, then add water until it reaches the volume of 100 liters. Heat dried cassava to 100 "C for 0.5 hours. Stir until cooked cassava into pulp and thickens.

4. Chill cassava porridge, and enter into langki sakarifikasi. Sakarifikasi is the process of decomposition of starch into glucose. After the cold, enter the fungus Aspergillus that will break down starch into glucose. To describe the 100 liters of cassava starch porridge. to 10 liters of solution fungus Aspergillus or 10% of the total pulp. Fungi concentrations reached 100-million cells / ml. Sebclum used, Aspergilhis dikuhurkan on cassava porridge was cooked to the adaptive nature of the chemical pulp with dried cassava. Breed fungi break down starch and work

5.Dua hours later, cassava porridge into 2 layers: water and sediment sugar. Stir again starch into sugar that is then put into fermentation tank. However, before making sure blood sugar is fermented starch solution up to 17-18%. That is the maximum sugar content like Saccharomyces unluk bacteria live and work break down sugar into alcohol. If high lebth sugar, add water until it reaches the desired level. Otherwise, add the sugar solution in order to achieve maximum sugar content.

6 Cover tightly fermentation tank to prevent contamination and Saccharomyces work more optimally extract the glucose. Aka anaerobic fermentation lasted not require oxygen. In order for optimal fermentation, keep the temperature at 28-32 "C and pH 4,5-5,5.

7. After 2-3 days, the starch solution into 3 layers. The bottom layer of protein deposition. On top of water, and ethanol. It is fermented beer containing 6-12% ethanol

8.Sedot ethanol solution with a plastic tube through a filter paper measuring 1 micron to filter out sediment protein.

9. Although filtered, ethanol was still bercampurair. To separate them, do distillate or distillation. Heat the mixture of water and ethanol at a temperature of 78 "C or the boiling point of ethanol equivalent. At that temperature evaporates first ethanol than the drip boiling water 100 ° C. Ethanol vapor flowed through the pipes so water-soaked and re-condensed into liquid ethanol.

10 The results of the distillation of 95% ethanol and insoluble in gasoline. In order larul, required ethanol yield is 99% ethanol or dried. Therefore, the need distilled absorbent. 95% ethanol is heated 100 "C. Angene temperature, ethanol and water evaporates. Steam them and then passed into the pipe walls were coated zeolite or starch. Zeolite will absorb the remaining water content up to 99% ethanol obtained ready dieampur denganbensin. Ten liters of ethanol 99%, need 120 to 130 liters of beer are produced from 25 kg of dried cassava

Read more

How to Make Charcoal

Charcoal is the black residue consisting of impure carbon obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis, the heating of wood, sugar, bone char, or other substances in the absence of oxygen (see pyrolysis, char and biochar). The resulting soft, brittle, lightweight, black, porous material resembles coal and is 85% to 98% carbon with the remainder consisting of volatile chemicals and ash

Historically, production of wood charcoal in districts where there is an abundance of wood dates back to a very ancient period, and generally consists of piling billets of wood on their ends so as to form a conical pile, openings being left at the bottom to admit air, with a central shaft to serve as a flue. The whole pile is covered with turf or moistened clay. The firing is begun at the bottom of the flue, and gradually spreads outwards and upwards. The success of the operation depends upon the rate of the combustion. Under average conditions, 100 parts of wood yield about 60 parts by volume, or 25 parts by weight, of charcoal; small scale production on the spot often yields only about 50%, large scale was efficient to about 90% even by the seventeenth century. The operation is so delicate that it was generally left to colliers (professional charcoal burners).
The massive production of charcoal (at its height employing hundreds of thousands, mainly in Alpine and neighbouring forests) was a major cause of deforestation, especially in Central Europe. In England, many woods were managed as coppices, which were cut and regrew cyclically, so that a steady supply of charcoal would be available (in principle) forever; complaints (as early as the Stuart period) about shortages may relate to the results of temporary over-exploitation or the impossibility of increasing production to match growing demand. The increasing scarcity of easily harvested wood was a major factor for the switch to the fossil fuel equivalents, mainly coal and brown coal for industrial use.
The modern process of carbonizing wood, either in small pieces or as sawdust in cast iron retorts, is extensively practiced where wood is scarce, and also for the recovery of valuable byproducts (wood spirit, pyroligneous acid, wood tar), which the process permits. The question of the temperature of the carbonization is important; according to J. Percy, wood becomes brown at 220 °C, a deep brown-black after some time at 280 °C, and an easily powdered mass at 310 °C.[citation needed] Charcoal made at 300° is brown, soft and friable, and readily inflames at 380 °C; made at higher temperatures it is hard and brittle, and does not fire until heated to about 700 °C.
In Finland and Scandinavia, the charcoal was considered the by-product of wood tar production. The best tar came from pine, thus pinewoods were cut down for tar pyrolysis. The residual charcoal was widely used as substitute for metallurgical coke in blast furnaces for smelting. Tar production led to rapid deforestation: it has been estimated all Finnish forests are younger than 300 years by their age. The end of tar production in the end of the 19th century meant also rapid re-forestation.
The charcoal briquette was first invented and patented by Ellsworth B. A. Zwoyer of Pennsylvania in 1897[1] and was produced by the Zwoyer Fuel Company. The process was further popularized by Henry Ford, who used wood and sawdust byproducts from automobile fabrication as a feedstock. Ford Charcoal went on to become the Kingsford Company.
The direct method uses heat from the incomplete combustion of the organic matter, which is to become charcoal. The rate of combustion is controlled by regulating the amount of oxygen allowed into the burn and is stopped by excluding oxygen before the charcoal itself begins to burn. This is the ages old method used by colliers to make charcoal in a pit, pile (clamp) or, more recently, in metal or masonry chambers (kilns). See the links below for more information.
The indirect method uses an external heat source to "cook" organic matter contained in a closed but vented airless chamber (retort). This is usually carried out in a metal or masonry chamber (furnace). The indirect method results in a higher yield of high quality charcoal with less smoke and pollutants and requires less skill and attention than the direct method.
For my first tests, I decided to try the indirect method. There had been some posts on a pyrotechnics newsgroup describing a procedure for making small quantities of willow or grapevine charcoal in a cookie tin or five gallon bucket. For the furnace, I used a 55 gal oil drum with the top cut out and a 12" wide X 10" high hole cut in the lower side for maintaining the fire. I used two iron rods stuck through the sides about 8" from the bottom to support the retort. I also kept the top which had been cut out. After the fire was well established , the top was placed on the drum and supported by rods to help hold the heat in yet allow a good draft. The retort was a 16 gal. steel drum with lid and I cut about six 3/8" holes in the bottom with an acetylene torch. I burned it out well in the furnace to eliminate petroleum residues. These drums are used for lubricants such as transmission fluid and gear grease and are readily available.

After the retort was loaded with air dried hickory the top was sealed and the drum was placed in the furnace or burn barrel. Wood scraps and bark were placed under the retort and around the sides and lit with newspaper assisted by a little burnt motor oil to get things off to a fast start. There was right much smoke for the first hour, but as things heated up and the moisture was driven off, it burned so clean that all you could see were heat waves. With the vent holes located in the bottom of the retort, the vapors and gasses were discharged into the hottest part of the fire and burned.

I stopped the first test too soon and only had about 1/3 charcoal. The rest was charred chunks of wood. The second test burned for about 3 hours, until the gasses had just stopped burning around the holes in the bottom. Results: 56# of wood yielded 17 1/2# charcoal or 32% by wet weight. Assuming an EMC (equilibrium moisture content) of 12%, The yield exceeds 35% on a dry matter basis. This is very good as most direct burns result in 20 to 25% at the best. I got over 2 1/2 five gallon buckets of good lump and only one large (4"X6") chunk showed signs of incomplete conversion with some brown in the center.

I was going to run a series of trials to compare the indirect method with direct (bottom lit) and direct (top lit). After several burns using the retort, I decided that there were such obvious advantages to the indirect method that I abandoned studies of direct burns. The retort method is easy, reliable, and does not require the skill and attention of direct burns. The equipment and materials which I used are readily available worldwide. As the gasses and volatiles are discharged into a hot bed of coals, I believe that most of the pollutants are burned, adding to the furnace heat. I also suspect that yield and quality are better. From what I have read, 35% by dry weight is excellent; the resulting charcoal burns hot and clean; you can almost light it with a match.

The indirect method also appears to be more compatible with heat recovery and waste wood utilization systems. I live on a farm in Virginia and my wife operates a small sawmill. Disposing of slabs and wood waste is a serious problem. I can burn a lot of the hardwood slabs in my indoor masonry heater/cooker. We have not found an economical use for pine slabs (we can't give them away) and have started burning them in a field. This is obviously a wasteful and polluting practice. My ultimate goal is to build a small masonry furnace that would hold several 55 gallon drum retorts and recover heat for domestic space heating during the winter. Charcoal could be a marketable by-product. I would burn pine slabs and waste wood in the furnace and make charcoal from hardwoods in 55 gallon drums. This approach appears to be very energy efficient as the gasses released by destructive distillation are utilized.

Read more

How to Make Cassava Flour

CASSAVA (Manihot esculenta Crantz.) is one of the most important cash crops in Thailand and Philippines. It is planted in about 1.2 million hectares, producing 17.7 million mt each year in Thailand. About 50-60% of this production serves as a raw material for cassava chips and pellets. These are exported to be mixed into livestock feeds, mainly to the European Common Market and some countries in Asia.
However, the price of cassava products is unstable, depending on the market demand each year. One way of solving this problem is to add value to them cassava through diversified usage, especially industrial utilization and human consumption. Processing cassava flour for human food is one solution to the problem of unstable prices for cassava products.

Adaptability of the technology

Thailand imports wheat flour for baked goods and other food products to a value of about US$120 million each year. The use of a locally produced cassava flour to replace wheat flour as a source of carbohydrate would reduce the cost of production and save on foreign exchange. The production of cassava flour is a simple technology that farmers can do for themselves. In this way, farmers can increase their incomes.

How to make the flour

To produce cassava flour, first wash the fresh roots then peel them. Wash the peeled roots. The roots are then chopped into small pieces about 5 x 0.5 x 0.2 cm, and sun-dried for two or three days (or dried in a hot air oven at 55oC). After drying, the moisture content of the cassava chips should be less than 8%. The chips are then milled, and the flour sieved through an 80 mesh sieve. Finally, the flour is packaged in plastic bags. Packaged in this way, the flour can be stored for at least eight months. The yield recovery of flour is about 20-40%, depending on the cultivar, the time of harvest, and the equipment used.

Avoiding Toxicity Problems

Good-quality cassava flour should be white and have a good smell. It should not be contaminated by insects or undesirable microorganisms. If drying takes place outdoors, this should be done on sunny days, otherwise the chips may smell bad and turn brown. It is best to use cassava cultivars which contain a low level of cyanogenic compounds, since these are potentially toxic. However, the cyanogenic content of fresh roots is not a serious problem in cassava flour production, since it is almost entirely eliminated during flour processing. Furthermore, Thailand's traditional cassava cultivars do not contain a high level of hydrocyanic acid. Our experiments on dried chips of cassava from nine cultivars found that the hydrocyanic content fell from 13.5-114.7 ppm in the fresh roots to 0.40-2.37 ppm in the flour. The level varied according to the cultivar and the time of harvest.

Cassava flour as substitute for wheat flour

Cassava flour does not contain any gluten. If it is used to replace wheat flour 100%, the quality of the product will be different. A suitable ratio for replacing wheat flour that consumers find acceptable depends on the kind of food. For example, cassava flour can replace 75% of wheat flour in sponge cakes and chiffon cakes, 50% in butter cakes and cookies, 25% in doughnuts and spaghetti, and 20% in bread. Cassava flour can be used to replace 25-50% of the rice starch in noodles, and will make the noodles softer and more elastic.

Source:www.agnet.org

Read more