{"id":3802,"date":"2016-09-20T21:54:28","date_gmt":"2016-09-20T19:54:28","guid":{"rendered":"https:\/\/www.biobang.com\/web\/?p=3802"},"modified":"2023-05-22T17:00:16","modified_gmt":"2023-05-22T15:00:16","slug":"once-upon-a-time-there-was-the-surface-crust-on-the-digester-2","status":"publish","type":"post","link":"https:\/\/www.biobang.com\/web\/da\/once-upon-a-time-there-was-the-surface-crust-on-the-digester-2\/","title":{"rendered":"Once upon a time, there was… the surface crust on the digester"},"content":{"rendered":"\n
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In the latest years, the problem of environmental pollution is particularly important, and the renewable energy sources are moving towards an increased and more efficient use. In this context, a relevant role is played by biogas, a gaseous biofuel (essentially methane), produced by some species of bacteria, which cause the fermentation of biological (either vegetal or animal) organic residues.<\/p>\n

The process was originally designed in order to recycle scrap materials from agriculture (straws and stalks of cereals), food industry (flour, confectionery, fruit and vegetables, cheese factories) or zootechnics (animal waste); but nowadays, also some cereals, cultivated on purpose, are commonly used. These materials, called \u00abbiomass\u00bb, are stored into dedicated silos (digesters), where the bacteria can act. It may occur even some weeks or months before the fermentation process is completed. The gas is then collected into big cylinders, for its normal use as an energy source.<\/p>\n

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\nBioBANG<\/span> BioBANG installed on the Biogas Plant<\/strong>\n<\/p>\n\n

The performance rate (tons of biogas per ton of biomass) and efficiency (time and electric or mechanical energy needed) of a plant can widely vary, according to many different factors and conditions (e.g., the biomass quality), but for sure, the more homogeneous and uniform is the incoming material, the higher the performance rate.<\/p>\n\n

BioBANG<\/span> can make the difference right here. By means of a special process (the so-called \u00abContrica®<\/sup> Cavitation\u00bb), BioBANG<\/span> makes the biomass homogeneous, facilitates bacteria in their fermentation activity, creates a regular flow inside the digester, and prevents the fermented material from standing either on the digester floor or walls. This \u00abold\u00bb material, in fact, could dry up, thus generating a hard crust, which (if not readily removed) could decrease the system performance and even brake the mixer.<\/p>\n\n

This is exactly what happened, some time ago, to an old-established farm, hosting a biogas plant. This company, whose main activity is cattle and pigs raising, some years ago, had a widescreen foresight in technology and decided to install a small system, to recycle its liquid scraps (i.e., animal waste), blended with on-purpose cultivated cereals. \n<\/p>\n

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\n Surface crust on the digester\u200b<\/strong>\n<\/p>\n

\nAt the beginning, everything fine. Just a few months after its start-up, however, the biogas system was not so performant as it was expected to be. In other words, it needed more time and energy to produce the same amount of fuel. It was but a small decrease, which was neither changing the payback time nor the capacity to supply the energy for the company internal consumption. So, the problem was qualified as normal, common to most of such types of equipment and hence neglected.<\/p>\n

\nAs time passed, however, the system performance was getting lower and lower, even if very slowly, and some little malfunctions were detected, which brought the technicians to decide for an internal repair. A thin crust was observed for the first time, both on the floor and on the sidewalls of the digester, composed of some dried, solid biomass. Again, the fact was considered as \u00abnormal\u00bb or, at least, \u00abunavoidable\u00bb. A periodical operation of maintenance and cleaning, made at the right moment, would prevent this event from increasing and becoming pervasive to the system. <\/p>\n\n

But sometimes facts overcome decisions and, in April 2016, with a performance of only 220 kW out of 550kW (and nevertheless still accepted by the owner!), the system, all of a sudden, broke down.\nThe technicians went into the digester and found a 2-meter-thick surface crust, which had caused the main mixer to crack. The only known strategy to eliminate the crust and recover the system to work, was long, expensive and risky. They would have to stop the equipment, open the digester, move the liquid biomass out, mechanically remove the crust and replace the broken mixer. Then, the system could restart. With two big issues: (i) the mechanical removal of the crust could have damaged the digester walls and (ii) the crust could rise up again in less than one year.<\/p>\n\n

A real nightmare.<\/p>\n\n

In the first days of May 2016, the company decided to contact BioBANG<\/span>. As a matter of fact, they were already aware about the cavitator and the beneficial effect it could have on their process, but had never decided to try and install it in their plant.
\nBioBANG<\/span> technicians, after a deep analysis, decided to avoid the removal of the crust, the digester opening and the replacement of the mixer, at least in the first step, but simply to immediately install BioBANG<\/span> in recirculation<\/span>. It was a challenge: should BioBANG have been able to melt and liquefy the surface crust, with no other external operation, the system would have been repaired with no additional costs, the investment return unchanged, the efficiency of 550kW restored and BioBANG<\/span> completely paid back in a while.
\nWhat happened? Only a few days after BioBANG<\/span> was installed, the surface crust was already getting thinner, in a fortnight it showed sensitively lower and, 2 months later, it.<\/p>\n

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Surface crust
\nearly May 2016\u200b\n<\/div>\n
\nSurface crust
\nend May 2016 \n<\/div>\n
\nSurface crust
\nearly June 2016\n<\/div>\n

During the treatment, there was no need to turn off the system, which has been regularly producing the biogas, with a slightly but steadily increasing performance. Thanks to BioBANG<\/span>, moreover, they could use some kinds of biomass with a higher quantity of fibers, cheaper for sure, but also lower in efficacy, with the \u00abtraditional\u00bb biogas generating systems. BioBANG<\/span>, in fact, is the only existing technology that is able to rapidly and completely digest all kinds of biomass, allowing up to a 20% saving in the daily charge.<\/p>\n

\nThis story clearly shows how the proper installation and use of BioBANG<\/span> can quickly turn a serious problem to a biogas plant into an opportunity to improve technology and save money. BioBANG<\/span> was able to completely overcome, in a short time, one of the most critical and frequent issues in biogas generation: the surface crust in the digester. Its action, in fact, transfers 100% of energy also to the poorest type of biomass, thus improving such requirements as mixing attitude, viscosity and pumping capability. In this way, the maximum performance rate of 550 kW can be easily and steadily achieved.<\/p>\n\n

In this way, the plant owner not only avoided spending money to stop the system (missed production), open the digester, remove the solid biomass, replace the mixer and, last but not least, re-create the biological equilibrium after the re-start; but also had a revenue. The best performance, in fact, was achieved with the smallest effort.<\/p>\n\n

Today, BioBANG<\/span> is working at its highest level of performance; the same quantity of biogas as before is obtained with a lower daily amount of biomass, no generation of surface crusts, lower power energy consumption. Absolutely unique.\nFinally, we can say that BioBANG<\/span> turned the incipit of a story into its conclusion: \u00abOnce upon a time, there was \u2026 a surface crust on the digester\u00bb<\/i>.<\/p>\n\n

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\nDigester at the end of June 2016<\/strong>\n<\/p>\n

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\nBESTIL DIN PR\u00d8VE MED BioBANG\u00ae<\/span> <\/a>\n<\/div>\n<\/div>\n\n<\/div>\n
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