I have come acrossed conventional biogas storages that were constructed from burnt bricks, low-grade concrete slabs and inferior polymeric materials. Consequently, the design suffered persistence gas leakage and excessive passage of air into the reaction chamber which intern slows down anaerobic digestion. The model does not permit easy sealing of cracks and punctures from the outside gas storage tank. Several complications during maintenance make it uncomfortable and expensive to repair broken sections of the plant.
Conventional designs also have gas storage tanks permanently attached to the digester there by making portability of biogas in storage tanks not possible. The gas produced by conventional plants can only be transported to the end user through gas pipelines which may be expensive or inefficient fo longer distance pipping since gas produced from such plants are in a range of smaller quantities.
External storage units such as foldable balloons may also be employed to store more gas for future demand and perhaps transportation. Pressure boosters (a.k.a air compressors) may be required to compensate extreme pressure loses in foldable balloons. Electricity required to operate pumps hinders the attractiveness of the technology in rural (remote).
Raw biogas contains CH4 (55-70%), CO2 (30-45%), H2S (20-20,000 ppm 2%) and H2O (2-7 %) hence, the effective gas storage volume is only nearly half of the actual gas storage tank. The dense property of CO2 makes it expensive to compress biogas into smaller storage volumes as well. Impurities found in the gas will also reduce combustion efficient of the biogas
Employing the principle of hydraulics effectively could set the design to next level. Hydralics in falling water and the natural rise of gases is what is so far been used in fixed dome conventional biogas gas transportation. The resulted pressure is just enough to transport the gas hrough the end use appliances but has no contribution to compressing the gas for effective storage. The hydralics principle is used extensively in puxin and deenbhandu models.