Our Technology

We ensure permanence of our plants. We provide tailor made services that satisfies the needs of our customers. Our experts study the exact requirements and find the right solution that optimizes the operation of your plant. Our team of experienced and expert professionals is always ready to take care of all your needs, quickly and efficiently. We try to build powerful public-private-people alliances for effective and sustainable community development with our technology. We focus on cumulative progress in every project that we undertake in the community.

Green Elephant has installed 02 No’s of anaerobic digester based on CSTR technology to treat 600 m³/day of spent wash generated by the distillery of Kisanveer Satara SSK Limited, Bhuinj. The Continuous Stirred Tank Reactor (CSTR) is a moderate rate, complete mix, anaerobic digestion process.

Green Elephant has its expertise in large-scale as well as mid-scale biogas plants (GreenBox™). The raw material is loaded with the pumps and the gas is stored and protected against whether in digesters having four stirring devices and double membrane roofs.

The technology of anaerobic digestion is being used since 1800. Now-a-days increasing number of anaerobic digestion plants are being built worldwide to generate clean renewable energy. Mid-scale biogas plants, such as the GreenBox™, are mainly used to treat the waste produced at homes, farms and supermarkets. This helps to divert and reuse the waste from landfill.

We supply reactors for industrial effluents to generate biogas for a wide range of industries such as distilleries, pulp & paper, rayon grade pulp, pharmaceuticals, food processing, petrochemicals, maize processing, dairies, etc. This is the technology that removes Sulphur from the biogas, natural gas and other gas streams.

Various industries having anaerobic digesters are currently using biogas as supplementary fuel for their boilers. With this, they get an option to produce clean biogas that generates their own captive power. Bio-scrubber is an economically attractive technology to remove H2S from biogas, natural gas and sour gas streams.

The Bio-scrubber is a caustic scrubber in which the utilized caustic solution is continuously regenerated in a bioreactor. The solution entering the scrubber at the top is sulphide free, resulting in a high concentration difference between the gas and liquid phases. At the same time, very high removal efficiency, in excess of 99%, can be easily obtained.

The valuable elemental, ‘Sulphur’, is obtained as by-product with purity up to 80 -90 %. Sulphur has no of applications in different types of industries. It can be directly used as fertilizer or as an additive to the fertilizers.

Advatages
i) Clean bio-technology for H2S cleaning.
ii) Low cleaning cost of biogas as up to 92 % of the caustic solution is recycled.
iii) Very high H2S removal efficiency – over 99 %.
iv) H2S reduction up to less than 200 ppm guaranteed with a Bio-scrubber system.
v) Partial absorption of Carbon Dioxide.
vi) No expensive catalyst and chemical required.
vii) Operation at ambient temperature and pressure.
viii) Elemental sulphur as by-product with 80 – 90 % purity.

Process Description

Green Elephant Engineering (GEE) has an improved water scrubbing process for biogas upgrading. This allows us to offer flexible, high quality twin-line gas upgrading plant, which can be delivered as prefabricated modules with final assembly on site.

The process consists of a scrubber process that includes absorption of Carbon Dioxide and Hydrogen Sulphide in circulating water. The upgrading system uses reused water in a re circulation process. The entire process is controlled by a PLC system, that can be monitored by a computer system.

Detailed Description:

1) The incoming Hydrogen Sulphide stripped biogas is compressed to 7-10 bar with a reciprocating compressor. The biogas usually contains small concentrations of Hydrogen Sulphide. Therefore an oil free compressor is needed. The compressed biogas is cooled with water from a cooling system.

2) After the cooling step, Carbon Dioxide and Hydrogen Sulphide are removed in a scrubber. The scrubber is packed with packing material for excellent mass and heat transfer. The absorption in the scrubber is most efficient at a low and constant water temperature. Carbon Dioxide and Hydrogen Sulphide will be removed by scrubbing in the absorber. The re-circulated water is fed into the absorber at the top, while the biogas flows through the absorber counter current, to the water. Intensive contact takes place in the absorber and the Carbon Dioxide and Hydrogen Sulphide contents in the biogas are reduced.

The absorber is filled with so called contact media for intensive mass transfer. On the top, there is water spraying system and a droplet separator. Since Carbon Dioxide and Hydrogen Sulphide are better soluble in water than methane, it is a very good method to remove Carbon Dioxide from the biogas and enrich the gas with Methane. Some methane will also be absorbed, but it can be recycled in the gas-freeing steps.

3) Used circulated water contains dissolved gasses including minor amounts of Methane. Therefore, the water is flashed to the pressure of 2 bar in a flash vessel in order to minimise the Methane losses. The water is partly degassed and gas from the flash tank is re-circulated into the inlet of the up-gradation unit. The Methane losses are controlled by adjustments of the pressure in the flash tank.

4) An adsorption dryer is installed after the water absorption column has removed water from the up-graded biogas. The dryer is self regenerating and consists out of two identical columns with drying agent. The columns are working alternately controlled by the PLC system.

5) The up-graded biogas is being dried and polished after the absorption stage before being delivered to the compression unit. In order to run the process optimally, CO2, CH4, H2O, H2S and Wobble Index are measured continuously. The PLC system controls the process according to the analysis’ results.

6) The clean biogas is fed to the high pressure compressor line where it is compressed at 250 bar and filled in the cascade through high pressure manifold.

The GreenBox™ is a state of the art, pre-fabricated, re-locatable, anaerobic digestion plant that provides customers with a potential zero discharge solution for organic waste, available in different capacities and degrees of automation.

The GreenBox ™ is a part of a larger portfolio of small, medium and large-scale biogas plants successfully being operated by Green Elephant, having international experiences in the biogas industry and numerous successfully commissioned references in India.

The GreenBox™ has the potential to reduce considerably carbon dioxide emissions. It is manufactured in IS 2062 grade steel with all flanges and connections as per ANSI standards and certification. Life of the GreenBox™ is approximately 15 years and the inside is coated by Epoxy with 550 microns for durability and non-corrosion. The GreenBox ™ is an award-winning Indo-German environmentally scientific waste disposal solution. The GreenBox ™ is available in different sizes starting from 500 kg per day, 1000 kg per day, and 1500 kg per day, 2000 kg per day and onwards.

Benefits of Biogas

Cleaner Environment


We use natural anaerobic digestion to produce clean energy. Thus, we contribute to the sustainable and clean environment. Producing biogas through anaerobic digestion reduces landfill waste, produces nutrient-rich liquid fertilisers, and requires less land than aerobic composting. We eliminate methane by disposing fermentable organic matter, thereby reducing the emission of methane gas (CH4) into the atmosphere. As a greenhouse gas, Methane is 21 times stronger than carbon dioxide. We produce clean and environment friendly organic fertilisers through this process.

Better Economics


Biogas reduces the cost of complying with Environmental Protection Agency (EPA) combustion requirements and can create a source of income for farmers or food producers. Industries and citizens can produce independent electricity and heat for their own needs. Alternatively, they can feed this produced energy into the electricity and gas grids. This reduces a countries dependency on fossil fuels and helps to develop a competitive economy.

Local Improvement


Biogas overpowers on traditional non-renewable resources, such as oil, coal and natural gas. Producing biogas creates jobs and benefits local communities. Citizens and industries make themselves independent from the suppliers and thus save costs.