Description:FIELD OF INVENTION

Embodiments of the present invention relate to the field of anaerobic digestion and renewable energy production. More particularly, embodiments of the present invention relate to a composition for biogas enhancer comprising coffee waste and micronutrients to enhance yield of biogas in digesters.

BACKGROUND

Biogas is a renewable fuel produced by anaerobic digestion of organic matter through a sequence of microbial processes, namely hydrolysis, acidogenesis, acetogenesis, and methanogenesis. The efficiency of these microbial conversions depends heavily on substrate quality and micronutrient availability. Common feedstocks include livestock waste, agricultural residues such as Napier grass or cotton stalks, and the biodegradable fraction of municipal solid waste (MSW). While anaerobic digestion is a well-established and environmentally sustainable method of waste-to-energy conversion, it often suffers from operational limitations such as slow start-up, nutrient imbalance, and inconsistent methane yield due to sub-optimal microbial activity.

Conventional enhancement techniques in the art include co-digestion strategies, trace metal supplementation, and pretreatment of lignocellulosic biomass. However, each has drawbacks. Pretreatment processes (e.g., alkali or acid hydrolysis) can improve hydrolysis but add cost, introduce chemical complexity, and require strict pH control. Liquid trace element formulations may improve microbial metabolism but typically suffer from limited shelf life, dosing complexity, and incompatibility across digester types.

Reference CN111607554B discloses a mixed metal salt formulation for enhancing biogas yield from cassava distiller's grain waste liquid. The composition includes cobalt chloride, nickel chloride, ferrous chloride, calcium chloride, and magnesium sulfate, among others. Although this formulation aids anaerobic fermentation, it is specifically tuned to a single feedstock (cassava distillery waste) and operates via liquid addition to fermentation broth. It lacks compatibility with solid substrates and does not address issues such as sustained nutrient release or dry-state shelf stability.

CN111607554B discloses a mixed metal salt formulation for enhancing biogas yield from cassava distiller's grain waste liquid. The composition includes cobalt chloride, nickel chloride, ferrous chloride, calcium chloride, and magnesium sulfate, among others. Although this formulation aids anaerobic fermentation, it is specifically tuned to a single feedstock (cassava distillery waste) and operates via liquid addition to fermentation broth. It lacks compatibility with solid substrates and does not address issues such as sustained nutrient release or dry-state shelf stability.

Battista et al. (2015) investigated biogas yield from chemically pretreated coffee waste. Although alkaline pretreatment improved methane yield, it required high-temperature control and the use of caustic reagents, making the process unsuitable for simple or rural digesters. Additionally, the focus was on physical/chemical enhancement of substrate digestibility rather than microbial nutrient activation.

Several nutrient formulations have been explored to enhance anaerobic digestion efficiency, particularly those using metal salts like cobalt chloride, nickel chloride, and magnesium sulfate, which have shown benefits in systems processing substrates such as cassava distiller’s waste. Studies have also examined the use of waste coffee grounds (WCG) as co-substrates due to their high organic and mineral content. However, such conventional methods often suffer from practical limitations. Liquid formulations are prone to degradation and require careful dosing, while WCG-based approaches face challenges in solubility, uniform mixing, and adaptability across digester types. Furthermore, many existing enhancers are designed for specific feedstocks or reactor conditions, limiting their universal applicability.

Therefore, there is a need for a dry, scalable, and compositionally stable biogas enhancer that can be seamlessly integrated into different anaerobic digestion setups. Such a formulation should provide consistent nutrient availability throughout the digestion cycle, support diverse feedstock types, and eliminate the need for costly pretreatment or chemical handling. It should also be shelf-stable, easily transportable, and suitable for dosing across both small-scale and industrial biogas systems without requiring modifications to reactor design or operating protocols.

SUMMARY

This summary is provided to introduce a selection of concepts, in a simple manner, which is further described in the detailed description of the disclosure. This summary is neither intended to identify key or essential inventive concepts of the subject matter nor to determine the scope of the disclosure.

In order to overcome the above deficiencies of the prior art, the present disclosure is to solve the technical problem of providing a composition for biogas enhancer that ensures consistent nutrient availability, supports diverse organic substrate, and improves biogas yield and process stability across various anaerobic digestion systems.

An embodiment of present invention discloses a composition for biogas enhancer, the composition comprising of 40% to 60% by weight of coffee waste, 35% to 50% by weight of micronutrients and 5.0% to 10.0% by weight of sucrose.

In accordance with an embodiment, the micronutrients comprise 1.0% to 2.0% by weight of cobalt chloride, 1.0% to 2.0% by weight of nickel chloride, 3.0% to 5.0% by weight of calcium chloride, 3.0% to 5.0% by weight of sodium chloride, 6.0% to 10.0% by weight of magnesium sulphate, 6.0% to 10.0% by weight of ferrous sulphate, 6.0% to 10.0% by weight of zinc sulphate and 6.0% to 10.0% by weight of potassium chloride.

In accordance with an embodiment, the composition for biogas enhancer comprises
50% by weight of coffee waste, 43% by weight of micronutrients, wherein the micronutrients comprise 1.5% by weight of cobalt chloride, 1.5% by weight of nickel chloride, 4% by weight of calcium chloride, 4% by weight of sodium chloride, 8% by weight of magnesium sulphate, 8% by weight of ferrous sulphate,
8% by weight of zinc sulphate, 8% by weight of potassium chloride, and 7% by weight of sucrose.

In accordance with an embodiment, the composition for biogas enhancer is applicable for use with an organic substrate used for anaerobic digestion, wherein the organic substrate comprises one or more feedstock materials.

In accordance with an embodiment, the one or more feedstock materials comprise cow dung, elephant dung, Napier grass, cotton stock, and biodegradable fraction of municipal solid waste (MSW) including vegetable peels, canteen food waste, and organic residues and combinations thereof.

In accordance with an embodiment, the coffee waste is dried to a moisture content of 6%–8%.

In accordance with an embodiment, the composition for biogas enhancer is a homogeneous mixture having a total solids content in the range of 90% to 94%, a pH between 6.1 and 6.8.

Another embodiment of the present invention discloses a method for preparing a composition for biogas enhancer, the method comprises drying coffee waste to reduce moisture content to below 10%. Blending the dried coffee waste with micronutrients and sucrose, wherein the micronutrients comprising cobalt chloride, nickel chloride, calcium chloride, sodium chloride, magnesium sulphate, ferrous sulphate, zinc sulphate, potassium chloride and testing the composition for biogas enhancer for parameters including total solids, pH, texture, and odour to ensure quality control before packaging.

In accordance with an embodiment, the blending being performed in a Rota-Mixer at variable batch sizes for a predefined duration to obtain a homogeneous mixture of the composition for biogas enhancer.

In accordance with an embodiment, the cover layer includes a vent port to facilitate air displacement and enhance sample flow.

In accordance with an embodiment, the predefined duration comprises 30 to 60 minutes according to the variable batch sizes.

In accordance with an embodiment, the blend of the composition for biogas enhancer is tested to ensure a pH between 6.1 and 6.8 and total solids between 90% and 94%.

Another embodiment of the present invention discloses a process for biogas enhancer, the process comprises providing a digester charged with an organic substrate used for anaerobic digestion thereof. Dissolving a predetermined dose of a composition for biogas enhancer in one of water and cow-dung slurry to form a dosing slurry. Introducing the dosing slurry into the digester along with the organic substrate. Maintaining anaerobic digestion conditions including one of a mesophilic and thermophilic temperature regime and generating enhanced biogas output.

In accordance with an embodiment, the composition for biogas enhancer comprises 40% to 60% by weight of coffee waste, 35% to 50% by weight of micronutrients and 5.0% to 10.0% by weight of sucrose.
In accordance with an embodiment, the composition for biogas enhancer is dosed at 0.2 to 0.8 grams per 500 mL in lab-scale digesters and up to 0.5 kg to 2 kg per ton of input substrate in industrial-scale digesters.

In accordance with an embodiment, the digester is selected from a batch-type anaerobic reactor, continuous stirred tank reactor (CSTR), or plug-flow reactor.

In accordance with an embodiment, the temperature in the digester is gradually increased from mesophilic (37°C) to thermophilic (45°C–47°C) to acclimatize microbial consortia and enhance digestion efficiency.

To further clarify the advantages and features of the present invention, a more particular description of the invention will follow by reference to specific embodiments thereof, which are illustrated in the appended figures. It is to be appreciated that these figures depict only typical embodiments of the invention and are therefore not to be considered limiting in scope. The invention will be described and explained with additional specificity and detail with the appended figures.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be described and explained with additional specificity and detail with the accompanying figures in which:

Figure 1 is a flowchart depicting a method preparing a composition for biogas enhancer, in accordance with an embodiment of the present invention; and
Figure 2 illustrates a graphical representation of total biogas yield (in millilitres) at different concentrations of the composition for biogas enhancer under controlled mesophilic conditions, in accordance with an embodiment of the present disclosure.
Further, those skilled in the art will appreciate that elements in the figures are illustrated for simplicity and may not have necessarily been drawn to scale. Furthermore, in terms of the method steps, chemical compounds, equipments and parameters used herein may have been represented in the figures by conventional symbols, and the figures may show only those specific details that are pertinent to understanding the embodiments of the present disclosure so as not to obscure the figures with details that will be readily apparent to those skilled in the art having the benefit of the description herein.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiment illustrated in the figures and specific language will be used to describe them. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Such alterations and further modifications in the illustrated system, and such further applications of the principles of the disclosure as would normally occur to those skilled in the art are to be construed as being within the scope of the present disclosure.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such a process or method. Similarly, one or more components, compounds, and ingredients preceded by "comprises... a" does not, without more constraints, preclude the existence of other components or compounds or ingredients or additional components. Appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but not necessarily do, all refer to the same embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this disclosure belongs. The system, methods, and examples provided herein are only illustrative and not intended to be limiting.

In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise.

Embodiments of the present disclosure relate to the field of anaerobic digestion and renewable energy production. More particularly, embodiments of the present invention relate to a composition for biogas enhancer comprising coffee waste and micronutrients to enhance yield of biogas in digesters.

Figure 1 is a flowchart depicting a method (100) for preparing the composition for biogas enhancer, in accordance with an embodiment of the present invention.

According to another exemplary embodiment of the disclosure, the method (100) for preparing the composition for biogas enhancer is disclosed.

At step 102, drying the coffee waste to reduce moisture content to below 10% and achieve a total solids (TS) content in the range of approximately 90% to 94%. The drying of the coffee waste is performed using a passive, non-thermal process such as sun drying, which avoids the use of fossil-fuel-based heating. The coffee waste is spread out in thin layers under direct sunlight for a duration of 2 to 3 days, depending on ambient weather conditions. During the drying, the coffee waste is periodically turned or agitated to ensure uniform drying and prevent microbial spoilage. Upon completion of the drying, the coffee waste exhibits a dark brown color, emits no foul odor, and has moisture content below 10%, between 6% and 8%, making it suitable for stable storage and further processing. The resulting dried coffee waste is characterized by a fine to medium granular texture that supports effective blending in subsequent formulation steps.

At step 104, blending the dried coffee waste with micronutrients and sucrose is done to obtain a homogenous mixture of the composition for biogas enhancer. The dried coffee waste, having the moisture content of 6–8% and the total solids in the range of 90–94%, is mixed with a predetermined proportion of the micronutrients and sucrose in a mechanical mixer, such as a Rota-Mixer. The micronutrients include cobalt chloride, nickel chloride, calcium chloride, sodium chloride, magnesium sulfate, ferrous sulfate, zinc sulfate, and potassium chloride. Sucrose is added in the range of 5.0–10.0% by weight to serve as a readily available carbon source for microbial activation. The mixing is carried out in batches of approximately 100 kg for a duration of 30–45 minutes under dry conditions at ambient temperature to ensure uniform dispersion of all components. The resultant blend of composition for biogas enhancer is a stable, free-flowing powder with consistent texture and colour, suitable for direct application in anaerobic digesters.

At step 106, testing the composition for biogas enhancer for parameters including total solids, pH, texture, and odour to ensure quality control before packaging is carried out using standard analytical methods. The total solids content is measured by gravimetric oven-drying and is maintained within 90–94% to ensure product stability and shelf life. The pH is assessed using a calibrated digital pH meter and is typically in the range of 6.1 to 6.8, ensuring compatibility with microbial consortia in the anaerobic digesters. Texture is manually evaluated to confirm the fine to medium powder consistency that supports uniform application and blending with substrates. Odour is checked through sensory inspection to confirm the absence of foul smells, indicating effective drying and microbial safety.

In an embodiment of the present invention, the composition for biogas enhancer and the method (100) for its preparation is provided. The composition for biogas enhancer comprises the coffee waste in range of 40% to 60% by weight, serving as an organic carrier and nutrient source, and the micronutrients comprising cobalt chloride (1.0%–2.0%), nickel chloride (1.0%–2.0%), calcium chloride (3.0%–5.0%), sodium chloride (3.0%–5.0%), magnesium sulfate (6.0%–10.0%), ferrous sulfate (6.0%–10.0%), zinc sulfate (6.0%–10.0%), and potassium chloride (6.0%–10.0%). The composition for biogas enhancer further includes the sucrose in the range of 5.0% to 10.0% by weight to provide an easily accessible carbon source for microbial activation. All the components are blended under the dry conditions to form the homogenous, free-flowing composition for biogas enhancer that is stable, easily dosable, and suitable for enhancing the microbial activity and the biogas yield in the anaerobic digesters.

Raw Material Collection
The coffee waste is used as the primary organic component in the composition for biogas enhancer. It is sourced weekly from various cafés located across Pune district, with an average collection volume ranging from 80 to 120 kilograms per week. The coffee waste is collected in a fresh, moist state and stored temporarily under hygienic conditions prior to processing.

Pre-processing
The collected coffee waste undergoes a sun-drying process for a period of 2 to 3 days, depending on ambient weather conditions. The drying process is passive and avoids the use of fossil-fuel-based heating, thereby making it eco-friendly and cost-effective. The goal is to reduce the moisture content to below 10% and achieve total solids (TS) in the range of 90% to 94% in the coffee waste. The final dried coffee waste appears dark brown in colour, has the fine to medium grind texture, and emits no foul odour making it suitable for stable storage and efficient blending.

Quality Characteristics of Dried Coffee Waste
Post-drying, the coffee waste exhibits the following characteristics:
Total Solids: 90% – 94%
Moisture Content: 6% – 8%
pH: 6.5 – 6.8
Texture: Fine to medium grind
These properties are ideal for maintaining shelf stability and ensuring uniform dispersion when combined with the micronutrients and sucrose.

Formulation Mixing
The coffee waste is blended with the micronutrients and sucrose using the Rota-Mixer with batch capacity of 100 kilograms. The blending process is carried out for 30 to 45 minutes under the dry conditions at ambient temperature to ensure homogeneity of the composition for biogas enhancer. The exact weight percentage of each component used in the composition for biogas enhancer is presented in Table 1 below.

Table 1: Weight percentage of components in the composition for biogas enhancer
Sr. No. Component Product Composition % Contribution Range
1 Cobalt chloride 1.5% 1.0 – 2.0%
2 Nickel chloride 1.5% 1.0 – 2.0%
3 Calcium Chloride 4% 3.0 – 5.0%
4 Sodium Chloride 4% 3.0 – 5.0%
5 Magnesium sulphate 8% 6.0 – 10.0%
6 Ferrous sulphate 8% 6.0 – 10.0%
7 Zinc sulphate 8% 6.0 – 10.0%
8 Potassium chloride 8% 6.0 – 10.0%
9 Coffee Waste 50% 40.0 – 60.0%
10 Sucrose 7% 5.0 – 10.0%

Quality Control (QC) Testing
Following the blending process, the composition for biogas enhancer undergoes quality control testing to ensure consistency, stability, and suitability for use in the anaerobic digesters. The key parameters evaluated include total solids, pH, texture, and odour. The total solids content of the composition for biogas enhancer is measured using the gravimetric oven-drying method and is maintained in the range of 90% to 94%, indicating low residual moisture and good shelf stability. The pH of the composition for biogas enhancer, measured using a calibrated digital pH meter, typically falls between 6.1 and 6.8, ensuring compatibility with the microbial consortia involved in biogas production. The texture and visual appearance of the composition for biogas enhancer are manually inspected to confirm the fine to medium brown powder that facilitates homogeneous dispersion during application. Odour is assessed through the sensory evaluation to verify the absence of foul or fermentative smells, which could indicate microbial spoilage or improper drying. Only those batches of composition for biogas enhancer that meet all defined quality control specifications are approved for packaging and distribution.

Packaging and Storage
The composition for biogas enhancer is packaged in airtight high-density polyethylene (HDPE) containers to prevent moisture ingress and contamination. It is made available in standard unit sizes of 1 kg, 5 kg, and 20 kg. Packaged units are stored in cool, dry environments at temperatures below 30°C with low ambient humidity to maintain product stability over extended periods. The dry formulation of composition for biogas enhancer enables ease of transport, extended shelf life, and direct application into the anaerobic digesters without requiring reconstitution or pretreatment.

Process of Using the Composition for Biogas Enhancement
In an embodiment of the present invention, a process is provided for using the composition for biogas enhancer to improve the efficiency and stability of the biogas production via the anaerobic digestion. The process comprises preparing a dosing slurry of the composition for biogas enhancer and introducing it into the anaerobic digester charged with one or more organic substrate.

The application process begins with commissioning the anaerobic digester using cow dung as inoculum source. The cow dung naturally contains a rich and diverse microbial consortium comprising acidogenic, acetogenic, and methanogenic bacteria. These microbes initiate and sustain anaerobic digestion process, eliminating the need for artificial microbial seeding. Once the microbial population is stabilized under the anaerobic conditions, the composition for biogas enhancer is introduced in the anaerobic digester.

The application process in an operational anaerobic digester, the composition for biogas enhancer can be directly applied along with the organic substrate such as Napier grass, municipal solid waste (MSW) organics, food waste slurry, or another biodegradable feedstock. In such cases, the composition for biogas enhancer is preferably pre-dissolved in the water or the cow dung slurry to ensure uniform distribution within the anaerobic digester, thereby enabling immediate microbial access to the micronutrients and accelerating the enhancement of the biogas yield.
The composition for biogas enhancer is dosed by dissolving a predefined quantity in either water or the cow dung slurry to form the dosing slurry. The dosing quantity varies by scale: in lab-scale reactors, the composition for biogas enhancer is typically applied at 0.2 to 0.8 grams per 500 mL of digestate. In industrial-scale operations, the composition for biogas enhancer may be applied in the range of 0.5 kg to 2 kg per ton of the organic substrate, depending on the organic substrate’s characteristics and the anaerobic digester type.

The dosing slurry is introduced into the anaerobic digester simultaneously with the organic substrate. The organic substrate may comprise one or more feedstock materials, including but not limited to:
Napier Grass: a high-fiber lignocellulosic biomass;
Cotton Stock: fibrous agricultural residues from cotton plants;
Cow Dung: used both as the organic feedstock material and the microbial inoculum;
Elephant Dung: similar to the cow dung, but with higher lignocellulosic content;
Biodegradable Municipal Solid Waste (MSW): including vegetable peels, canteen food waste, and other pulped organic residues manually segregated from inorganics such as plastics, metals, and glass.

The process is applicable to various types of the anaerobic digesters, including batch-type reactors, continuous stirred tank reactors (CSTRs), and plug-flow reactors. The anaerobic digestion is carried out under either mesophilic conditions (approximately 37°C) or thermophilic conditions (approximately 45°C to 47°C).

In certain embodiments, particularly in the industrial-scale operations, the digester may be transitioned gradually from mesophilic to thermophilic regimes. This is accomplished using a controlled temperature ramping strategy, typically increasing the temperature by 1–2°C per week, to acclimatize the microbial consortia without causing disruption or shock. This approach enables more efficient hydrolysis and methanogenesis, especially for fibrous or high-solid organic substrate.

The composition for biogas enhancer works synergistically with the native microbial consortia present in the anaerobic digester to improve the anaerobic digestion process. It supports acidogenesis by facilitating the breakdown of complex organic matter into volatile fatty acids and intermediates. It further promotes acetogenesis, enabling the efficient conversion of these intermediates into acetic acid, carbon dioxide, and hydrogen precursors essential for the biogas production. The presence of the micronutrients in the composition for biogas enhancer, enhances methanogenesis by activating key enzymatic pathways involved in methane formation. Additionally, the composition for biogas enhancer helps stabilize the pH and buffer capacity within the anaerobic digester environment, ensuring microbial homeostasis. This combined action reduces the lag phase typically observed in the biogas production and leads to higher cumulative biogas yields over the digestion cycle.

The overall effect of the invention is a substantial improvement in biogas volume, digestion efficiency, and process stability, across a range of the organic feedstock materials and reactor configurations.

The present invention is explained further in the following specific working examples, which are only by way of illustration and are not to be construed as limiting the scope of the invention.

Working Examples

Example 1: Lab-Scale Evaluation of Biogas Enhancer
A laboratory-scale experiment was conducted to evaluate effectiveness of the composition for biogas enhancer under the mesophilic conditions. The anaerobic digestion was carried out in 500 mL airtight laboratory reactors using the fresh cow dung slurry as the organic substrate. The composition for biogas enhancer was tested at four different dosages: 0.2 g, 0.4 g, 0.6 g, and 0.8 g per 500 mL reactor volume. All setups were maintained at a constant temperature of 37°C to simulate the mesophilic conditions, and the biogas yield was recorded daily over a period of 30 days.

Figure 2 illustrates a graphical representation (200) of total biogas yield (in millilitres) at different concentrations of the composition for biogas enhancer under the mesophilic conditions. The composition for biogas enhancer was evaluated at four different dosages 0.2 g, 0.4 g, 0.6 g, and 0.8 g per 500 mL anaerobic reactor. As shown, the biogas yield increases with the composition for biogas enhancer concentration up to 0.6 g, which yielded the highest biogas volume of approximately 443.33 mL. Beyond this optimum, a further increase to 0.8 g resulted in a decline in the biogas output to 111.67 mL, indicating possible microbial inhibition at higher concentrations. The data as shown in the Table 2 demonstrate that the optimum dosage range for enhanced methane generation lies between 0.4 g and 0.6 g of the product per reactor volume, in accordance with an embodiment of the present disclosure.

Table 2: Biogas yield at different dosage range (Lab-Scale)
Product Concentration (in grams) Total Biogas (ml)
0.2 136.67
0.4 401
0.6 443.33
0.8 111.67

Example 2: Field-Scale application in continuous stirred tank reactor (CSTR)
A full-scale trial was carried out in a continuous stirred tank reactor (CSTR) having a capacity of 1500 m³. The organic substrate consisted of the Napier grass and the cow dung (total solids ~8%). The composition for biogas enhancer was applied at a rate of 3 kg/day (1 kg per shift), mixed with 200 L of water and dosed into the pretreatment tank. The trial was conducted over a period from January 8, 2025, to March 1, 2025, under the mesophilic conditions with continuous mixing.

Following the application of the composition for biogas enhancer, daily biogas yield increased from an average of 800–1000 m³ to 1100–1250 m³ as shown in Table 3. Additionally, the total solids reduction improved significantly from 36.25% to 55.5%.

Table 3: Field-Scale Performance in CSTR
Parameter Baseline (Before
Product) After Product Improvement
Biogas Yield
(m³/day) ~800 – 1000 1100 – 1250 ↑ 25–30%
TS Reduction (%) 36.25% 55.5% ↑ Digestion efficiency

The application of the composition for biogas enhancer resulted in an enhancement of the biogas yield by 47.23%, based on the total solids input. A 19.25% improvement in the total solid reduction was observed, contributing to more complete digestion. This increase in solids breakdown also led to a reduction in scum formation, thereby improving operational stability and reducing the need for mechanical intervention.

Example 3: Thermophilic Transition in Plug Flow Reactor
A separate field trial was conducted at a 1403 m³ plug flow reactor treating he organic substrate consisting of cotton stalk, elephant dung, and cow dung (approx. 20 tons/day). The composition for biogas enhancer was dosed at 7.5 kg/day mixed in 200 L of water. The plug flow reactor was gradually transitioned from the mesophilic (37°C) to thermophilic (45–47°C) conditions over four weeks, allowing microbial adaptation.

During the trial period (January 8 to March 1, 2025), the biogas yield rose from a baseline of ~200–950 m³/day to 600–1100 m³/day as shown in Table 4. Total solids reduction improved from 26.96% to 37.54%, reflecting enhanced digestion performance and stability under the thermophilic conditions.

Table 4: Performance in Plug Flow Reactor under thermophilic transition
Parameter Baseline (Before
Product) After Product Improvement
Biogas Yield
(m³/day) ~200 – 950 600 – 1100 ↑ 25–30%
TS Reduction (%) 26.96% 37.54% ↑ Digestion efficiency

The application of the composition for biogas enhancer under the thermophilic conditions resulted in a 25.9% increase in biogas yield, based on the total solids input. Furthermore, a 10.58% enhancement in the total solids reduction was achieved, indicating more efficient digestion and conversion of complex biomass. As with the CSTR system, the reduction in residual solids contributed to lower scum formation, thereby facilitating improved operational continuity and reduced downtime.

Numerous advantages of the present disclosure may be apparent from the discussion above. In accordance with the present disclosure.

While specific language has been used to describe the invention, any limitations arising on account of the same are not intended. As would be apparent to a person skilled in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein.

The figures and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, order of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts need to be necessarily performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples.
, Claims:WE CLAIM,
1. A composition for biogas enhancer, the composition comprising:
40% to 60% by weight of coffee waste;
35% to 50% by weight of micronutrients; and
5.0% to 10.0% by weight of sucrose.

2. The composition as claimed in claim 1, wherein the micronutrients comprise
1.0% to 2.0% by weight of cobalt chloride;
1.0% to 2.0% by weight of nickel chloride;
3.0% to 5.0% by weight of calcium chloride;
3.0% to 5.0% by weight of sodium chloride;
6.0% to 10.0% by weight of magnesium sulphate;
6.0% to 10.0% by weight of ferrous sulphate;
6.0% to 10.0% by weight of zinc sulphate; and
6.0% to 10.0% by weight of potassium chloride.

3. The composition as claimed in claim 1, wherein the composition for biogas enhancer comprises
50% by weight of coffee waste;
43% by weight of micronutrients, wherein the micronutrients comprise
1.5% by weight of cobalt chloride;
1.5% by weight of nickel chloride;
4% by weight of calcium chloride;
4% by weight of sodium chloride;
8% by weight of magnesium sulphate;
8% by weight of ferrous sulphate;
8% by weight of zinc sulphate;
8% by weight of potassium chloride; and
7% by weight of sucrose.

4. The composition as claimed in claim 1, wherein the composition for biogas enhancer is applicable for use with an organic substrate used for anaerobic digestion, wherein the organic substrate comprises one or more feedstock materials.

5. The composition as claimed in claim 1, wherein the one or more feedstock materials comprise cow dung, elephant dung, Napier grass, cotton stock, and biodegradable fraction of municipal solid waste (MSW) including vegetable peels, canteen food waste, and organic residues and combinations thereof.

6. The composition as claimed in claim 1, wherein the coffee waste is dried to a moisture content of 6%–8%.

7. The composition as claimed in claim 1, wherein the composition for biogas enhancer is a homogeneous mixture having a total solids content in the range of 90% to 94%, a pH between 6.1 and 6.8.

8. A method (100) for preparing a composition for biogas enhancer, the method comprising:
drying coffee waste to reduce moisture content to below 10%;
blending the dried coffee waste with micronutrients and sucrose,
wherein the micronutrients comprising cobalt chloride, nickel chloride, calcium chloride, sodium chloride, magnesium sulphate, ferrous sulphate, zinc sulphate, potassium chloride; and
testing the composition for biogas enhancer for parameters including total solids, pH, texture, and odour to ensure quality control before packaging.

9. The method (100) as claimed in claim 8, wherein the blending is performed in a Rota-Mixer at variable batch sizes for a predefined duration to obtain a homogeneous mixture of the composition for biogas enhancer.

10. The method (100) as claimed in claim 8, wherein the predefined duration comprises 30 to 60 minutes according to the variable batch sizes.

11. The method (100) as claimed in claim 8, wherein the blend of the composition for biogas enhancer is tested to ensure a pH between 6.1 and 6.8 and total solids between 90% and 94%.

12. A process for biogas enhancer, the process comprising:
providing a digester charged with an organic substrate used for anaerobic digestion thereof;
dissolving a predetermined dose of a composition for biogas enhancer in one of water and cow-dung slurry to form a dosing slurry;
introducing the dosing slurry into the digester along with the organic substrate;
maintaining anaerobic digestion conditions including one of a mesophilic and thermophilic temperature regime; and
generating enhanced biogas output.

13. The process as claimed in claim 12, wherein the composition for biogas enhancer comprises:
40% to 60% by weight of coffee waste;
35% to 50% by weight of micronutrients; and
5.0% to 10.0% by weight of sucrose.

14. The process as claimed in claim 12, wherein the composition for biogas enhancer is dosed at 0.2 to 0.8 grams per 500 mL in lab-scale digesters and up to 0.5 kg to 2 kg per ton of input substrate in industrial-scale digesters.

15. The process as claimed in claim 12, wherein the digester is selected from a batch-type anaerobic reactor, continuous stirred tank reactor (CSTR), or plug-flow reactor.

16. The process as claimed in claim 12, wherein the temperature in the digester is gradually increased from mesophilic (37°C) to thermophilic (45°C–47°C) to acclimatize microbial consortia and enhance digestion efficiency.

Dated this 28th day of August 2025

Vidya Bhaskar Singh Nandiyal
Patent Agent (IN/PA-2912)
Agent for Applicant